US3927300A - Electric fluid heater and resistance heating element therefor - Google Patents

Electric fluid heater and resistance heating element therefor Download PDF

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US3927300A
US3927300A US447513A US44751374A US3927300A US 3927300 A US3927300 A US 3927300A US 447513 A US447513 A US 447513A US 44751374 A US44751374 A US 44751374A US 3927300 A US3927300 A US 3927300A
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heating element
channels
heater
structural body
honeycomb structural
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US447513A
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Shigetaka Wada
Noboru Yamamoto
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NGK Insulators Ltd
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NGK Insulators Ltd
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    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05BELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00Ohmic-resistance heating
    • H05B3/10Heater elements characterised by the composition or nature of the materials or by the arrangement of the conductor
    • H05B3/12Heater elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material
    • H05B3/14Heater elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material the material being non-metallic
    • H05B3/141Conductive ceramics, e.g. metal oxides, metal carbides, barium titanate, ferrites, zirconia, vitrous compounds
    • AHUMAN NECESSITIES
    • A45HAND OR TRAVELLING ARTICLES
    • A45DHAIRDRESSING OR SHAVING EQUIPMENT; EQUIPMENT FOR COSMETICS OR COSMETIC TREATMENTS, e.g. FOR MANICURING OR PEDICURING
    • A45D20/00Hair drying devices; Accessories therefor
    • A45D20/04Hot-air producers
    • A45D20/08Hot-air producers heated electrically
    • A45D20/10Hand-held drying devices, e.g. air douches
    • A45D20/12Details thereof or accessories therefor, e.g. nozzles, stands
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24HFLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
    • F24H1/00Water heaters, e.g. boilers, continuous-flow heaters or water-storage heaters
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24HFLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
    • F24H3/00Air heaters
    • F24H3/02Air heaters with forced circulation
    • F24H3/04Air heaters with forced circulation the air being in direct contact with the heating medium, e.g. electric heating element
    • F24H3/0405Air heaters with forced circulation the air being in direct contact with the heating medium, e.g. electric heating element using electric energy supply, e.g. the heating medium being a resistive element; Heating by direct contact, i.e. with resistive elements, electrodes and fins being bonded together without additional element in-between
    • F24H3/0411Air heaters with forced circulation the air being in direct contact with the heating medium, e.g. electric heating element using electric energy supply, e.g. the heating medium being a resistive element; Heating by direct contact, i.e. with resistive elements, electrodes and fins being bonded together without additional element in-between for domestic or space-heating systems
    • F24H3/0417Air heaters with forced circulation the air being in direct contact with the heating medium, e.g. electric heating element using electric energy supply, e.g. the heating medium being a resistive element; Heating by direct contact, i.e. with resistive elements, electrodes and fins being bonded together without additional element in-between for domestic or space-heating systems portable or mobile
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24HFLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
    • F24H9/00Details
    • F24H9/18Arrangement or mounting of grates or heating means
    • F24H9/1854Arrangement or mounting of grates or heating means for air heaters
    • F24H9/1863Arrangement or mounting of electric heating means
    • F24H9/1872PTC
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01CRESISTORS
    • H01C1/00Details
    • H01C1/14Terminals or tapping points or electrodes specially adapted for resistors; Arrangements of terminals or tapping points or electrodes on resistors
    • H01C1/1406Terminals or electrodes formed on resistive elements having positive temperature coefficient
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01CRESISTORS
    • H01C7/00Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
    • H01C7/02Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material having positive temperature coefficient
    • H01C7/022Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material having positive temperature coefficient mainly consisting of non-metallic substances

Definitions

  • An electric fluid heating element comprises a column- Mar. 9, Japan haped honeycomb gagtural of an electrically conductive cermaic material having a positive temper- U-S- Clature oefficient of resistance
  • The has a multi- 3 1 5 3355/22 252/520 plicity of substantially uniform parallel channels ex- [51] Cum H053 3/14; HOlC 7/02; F24H 1/10; tending therethrough with each of the channels being F24H 3/04 bounded by a partition wall which is substantially uni-
  • the body has a Surface to volume 23, ratio in the range of 10 to 60 cm /cm and is selfcon- 362, 58; 252/518 520 trolling without the necessity of a safety device such as a fuse or thermostat.
  • Ohmic electrodes are mounted [56] References Cited on oppsoite surfaces of the body to supply heating UNITED STATES PATENTS current thereto.
  • the heating element can be used as 927,173 7/1909 Schluter 219/381 the heating means in an air heater, humidifier of liquid 1,334,809 3/1920 Simon et a1. 219/381 UX heaten 3,163,841 12/1964 Willett 219/374 UX 8 Cl 8 D F. 3,244,860 4/1966 Lindley 219/382 x rawmg gums OHMIC ELECTRODE PTC CERAMIC MATERIAL OHMIC ELECTRODE sheet 1 of5 3,927,300
  • This invention relates to heating elements, and more particularly to a heating element comprising a ceramic article having a positive temperature coefficient of electric resistance (hereinafter referred to as PTC ceramic article).
  • the element is composed of a honeycomb structural body and includes a pair of ohmic electrodes.
  • the element is adapted to generate a large amount of heat radiation with a small volume without any risk of overheating and breaking.
  • the invention also includes a heater comprising this heating element which is particularly useful as an air heater, dryers inclusive of a hair dryer, air towel, liquid heater, humidifier, volatilizer and the like.
  • honeycomb structural body shall be understood to mean a structural body having a multiplicity of channels extending therethrough and generally parallel to each other and having high surface-to-volume ratios.
  • Metal has a small specific resistance and hence is commonly used in linear form in the heating element. If such heating element is used, for example, in a hair dryer and a fan is used to feed air therethrough, and suction opening is clogged, the metal constituting the heating element becomes overheated, causing a fire. Eventually there is a risk of the metal being oxidized and broken.
  • the ceramic article having a negative temperature coefficient of electric resistance is commonly formed into a rod having a pair of ohmic electrodes mounted thereon and used as a heating element.
  • a ceramic article for example, silicon carbide in order to generate a given amount of heat radiation without overheating the heating element per se, a number of these heating elements must be used simultaneously. Alternatively temperature control means must be used, and as a result, the assembly becomes complex in construction and/or there is a risk of the heating element being broken. Thus, such a heating element is not suitable for use with domestic heaters.
  • a PTC ceramic article made of semiconductive barium titanate has commonly been formed into a disc-shaped pellet on which are mounted a pair of ohmic electrodes for use as a heating element.
  • Such kind of heating element can only generate the amount of heat radiation corresponding to a few watts from one heating element.
  • a large heat radiating plate must be added thereto.
  • this kind of heating element is subjected to restrictions in its construction.
  • a number of heating elements each including the above described heat radiating plate are required.
  • the use of the measures described is extremely uneconomical and results in considerable constructional disadvantage as that it could not be applied to domestic heat radiators.
  • a heating element comprising a cylindrical PTC ceramic article which is provided at its inner and outer surfaces with ohmic electrodes has been known. If this heating element has its surface area of about 1,000 cm in order to obtain a sufficiently large amount of heat radiation, for a the diameter of 5 cm it is necessary to make the length longer than 30 cm. As a result, the volume of the heating element becomes too large as compared with the volume of the customary type of heating element. Thus, the mechanical strength of the heating element becomes lowered and this type of heating element has not achieved any importance in actual practice.
  • the invention is based upon recognition of the fact that a PTC ceramic article composed of a honeycomb structural body provides a heating element which is small in volume and which can generate a large amount of heat radiation without overheating and breaking.
  • the invention thus provides a heater comprising the above described heating element and particularly useful in air heater, dryers inclusive of a hair dryer, air towel, liquid heater, humidifer, volatilizer and the like.
  • the principal object of the invention is to provide a heating element comprising a PTC ceramic article composed of a honeycomb structural body.
  • Another object of the invention is to provide a heater, which comprises a heating element comprising a PTC ceramic article composed of a honeycomb structural body and particularly useful as an air heater, dryers inclusive of a hair dryer, air towel, liquid heater, humidifer, volatilizer and the like.
  • a further object of the invention is to provide various types of heaters each having a preferable construction.
  • a still further object of the invention is to provide a method of producing a heating element comprising a PTC ceramic article composed of a honeycomb structural body and to provide a method of forming ohmic electrodes therefor.
  • FIG. 1 is a perspective view of a preferred embodiment of the heating element according to the invention.
  • FIG. 2 is a section along line IIII in FIG. 1;
  • FIG. 3 is a perspective view of another embodiment of the heating element according to the invention.
  • FIG. 4 is a section along line IV-IV in FIG. 3;
  • FIG. 5 is a graph which illustrates the relation between the amount of heat radiated from the heating element according to the invention and the amount of air fed to the heating element;
  • FIG. 6 is a perspective view of a preferred embodiment of an air heater employing the heating element according to the invention, a part being broken away for clarity;
  • FIG. 7 is a perspective view of a preferred embodiment of a liquid heater employing the heating element according to the invention, a part being broken away for clarity;
  • FIG. 8 is a perspective view of a preferred embodiment of a humidifier employing the heating element according to the invention, a part being broken away 3 for clarity.
  • a heating element 1 is shown according to the invention which is composed of a honeycomb structural body provided with a multiplicity of channels 2 extending therethrough and generally parallel to each other. Each of these channels 2 is bounded by a partition wall 3 which is substantially uniform in thickness.
  • the honeycomb structural body constructed as above described insures extremely high surface-tovolume ratios.
  • the partition walls 3 are provided at their opposed end surfaces substantially perpendicular to theaxial direction of the channels 2 with a pair of ohmic electrodes 4, 5, respectively.
  • the thickness of both the partition wall 3 and ohmic electrodes 4, 5 is shown in enlarged scale in FIGS. 1 and 2 for clarity.
  • BaCo TiO SiO and La O were weighed with mole ratios of l.00:1.02:0.02:0.003, respectively, mixed in a ball mill with rubber lining for 12 hours, dried and calcined at 1,100C for 3 hours.
  • the calcined raw material was roughly pulverized by a double roll crusher with alumina rolls and then finely pulverized in a ball mill with rubber lining for 6 hours.
  • the finely pulverized particles were passed through a screen with a mesh of 149 microns and then dried.
  • To 100 parts by weight of the dried powders were added 4 parts by weight of methyl cellulose, 16.5 cc of 12% polyvinyl alcohol water solution, 3 parts by weight of polyethylene glycol and 8.5 parts by weight of water.
  • the mixture was well blended in a kneader and then subjeted to de-ain'ng while blending with the aid of a de-airing pug mill.
  • the product thus obtained was extruded from the de-airing pug mill through a honeycomb structural body forming nozzle so as to form a green body composed of a honeycomb structural body.
  • the green body thus obtained was dried by means of a freeze drying method using dry ice and then fired in a standard electric furnace using silicon carbide heaters at l,350 C for 2 hours.
  • a column shaped honeycomb structural body having a diameter of 4 cm and a thickness of 1 cm (length of channels) and provided with a multiplicity of channels each square in section having each side of 0.195 cm and bounded by a partition wall having a thickness of 0.03 cm was thereby obtained.
  • the honeycomb structural body has surface-to-volume ratios of about 16 cm /cm and total surface area of about 200 cm Ohmic electrodes were provided for each end surface substantially perpendicular to the axial direction of the channel, thus completing a heating element.
  • The, ceramic compositions are not restricted to the above described ceramic composition and any other customary compositions which can obtain a positive temperature coefficient of electric resistance may also be used.
  • Examples of such ceramic compositions are those described in U.S. Pat. Application Ser. No. 431,397 filed on Jan. 7, 1974 which is a continuationin-part of Application Ser. No. 256,368 filed on May 24, 1972; now abandoned and those described in U.S. Pat. No. 2,981,699, No. 3,373,120 and No. 3,441,517, respectively.
  • the honeycomb structural body may be formed by any methods other than the above described extrusion method. Examples of these methods are a press method, a method of producing a bundle of a number of green ceramic pipes and then firing the bundle, or a method of forming a honeycomb structural body comprising coating ceramic raw material particles suspended in an organic binder on the surface of sheet of paper and the like, corrugating the coated sheet of paper and the like, accumulating the corrugated sheet of paper and the like and firing the accumulated sheet of paper and the like as disclosedin U.S. Pat. No. 3,112,184.
  • sectional configuration of the channels may be formed into any configurations other than square as shown in FIGS. 1 and 3, such, for example, as triangular, hexagonal or any other polygonal, circular and the like sectional configurations (not shown).
  • the outer configuration of the honeycomb structural body constituting the essential part of the heating element is shown as columnar in shape in FIG. 1 and rectangular parallelepipe in shape in FIG. 3, but if necessary the outer configuration of the honeycomb structural body may be of cube, polygonal columnar in shape (not shown).
  • the honeycomb structural body is provided at its each end surface substantially perpendicular to the axial direction of the channels with the ohmic electrode.
  • these ohmic electrodes may be mounted on any positions other than end surfaces of the honeycomb structural body.
  • the honeycomb structural body may be provided at its each side surface 6, 7 which is substantially parallel to the axial direction of the channels and opposed to each other with a pair of electrodes 8, 9 as shown in FIGS. 3 and 4.
  • Whether the ohmic electrodes should be mounted on the surfaces substantially perpendicular to the axial direction of the channels or mounted on the outer surfaces of the honeycomb structural body substantially parallel to the axial direction of the channels may be determined depending on the outer configuration of the honeycomb structural body its mechanical strength, the purpose to which the honeycomb structural body is used, the amount of heat radiation, the restriction in design of the heater into which the honeycomb structural body is incorporated as a heating element and any other various conditions.
  • FIGS. 2 and 4 the thickness of the partition wall 3 and ohmic electrodes 8, 9 is shown in enlarged scale for clarity.
  • the ohmic electrodes may be formed on the outer surfaces of honeycomb structural body by means of such a common method as those described, for example, in U.S. Pat. No. 3,676,211, British vPat. No. 1,252,490, Electrodes for Ceramic Barium Titanate Type Semiconductors by H. M. Landis, Journal of Applied Physics, 1965, Vol. 36, Nos. 6, pages 2,000 to 2,001 and the like. But, it is preferable to form the ohmic electrodes on the outer surfaces of the honeycomb structural body by means of the following method in order to produce the heating element according to the invention.
  • the silver paste baking method comprises coating silver paste on the ceramic article by means of a screen printing method and-baking the coated surfaces.
  • silver paste having the typical composition used with a customary condenser for example, Silver Paste 7095 made by E. I. Du Pont de Nemours and Company, could not provide the ohmic electrodes which are well suited for the PTC ceramic article.
  • Such a disadvantage can be obviated by the use of a silver paste containing indium.
  • such indium containing silver paste is expensive.
  • the silver paste developed by the invention consists of silver and zinc with a range of weight ratios of 2:1 to 40:1, glass powder, and an organic solvent. This silver paste after coating is baked at a temperature of 420 to 550C.
  • the aluminum hot spraying method is capable of providing electrodes which can eliminate the above described difficult problem which has been encountered with the silver paste baking method.
  • the aluminum hot spraying method it has been the common practice to spray aluminum against surfaces of a ceramic article in a direction substantially perpendicular thereto so as to expedite adherence of aluminum to those surfaces, as described in the US. Pat. No. 3,676,211. If aluminum is sprayed from a direction perpendicular to the surfaces which is substantially perpendicular to the axial direction of the channels of the honeycomb structural body, that is, from the direction substantially parallel to the axial direction of the channels, aluminum becomes adhered 'to the inner wall surfaces of all of the channels, thereby shortcircuiting the sprayed surfaces.
  • the invention provides an improved method wherein aluminum is sprayed in a direction inclined from the surfaces which is substantially perpendicular to the axial direction of the channels by an angle of to 60, preferably, to 45.
  • the ceramic article is plated with nickel as a whole.
  • the invention provides an improved electroless nickel plating method by which nickel is plated on surfaces only substantially perpendicular to the axial direction of the channels and which comprises immersing the honeycomb structural body into silicon resin or wax, for example,,to mask the total body with the resin or wax, grinding the surfaces substantially perpendicular to the axial direction of the channels to remove the mask, subjecting activating treatment only to the mask removed surface, and immersing the body into nickel salts solution to form ohmic electrodes on the surfaces only substantially perpendicular to the axial direction of the channels.
  • each channel is maderound in shape at its corner edges.
  • These masked round corner edge portions can prevent a penetration of the activating treating liquid into the channels due to surface tension and hence prevent an electroless plating against the inner walls of the channels, thereby preventing shortcircuit across the electrodes.
  • a heater employing the heating element according to the invention will now be described in greater detail.
  • a heating element comprising a PTC ceramic article composed of a honeycomb structural body which is provided with a multiplicity of channels each square in cross section with a side of 0.125 cm and bounded by partition walls whose thickness is 0.02 cm.
  • the heating element is provided at its surface substantially perpendicular to the axial direction of each channel with ohmic electrodes.
  • a curve 101 graphically illustrates the relation between the amount of air Q (m /min) fed into the channels of the heating element at 20C and the amount of heat P (watt) radiated from the above mentioned heating element.
  • the amount of heat radiation is about 230 watts when the amount of air fed is 0.1 m /min, whereas if the amount of air fed is increased to 0.5 m /min which is 5 times larger than 0.1 m /min, the amount of heat radiation becomes also increased to about 450 watts. If the amount of air fed is substantially zero, that is, if the forced draft is stopped and use is made of natural convection air caused by the heat radiated from the heating element, the amount of heat radiation becomes only 20 watts.
  • a heater comprising the heating element according to the invention and means for feeding fluid through the heating element such, for example, as'a fan, pump, water pressure of city water and the like can prevent an overheating of the heating element when the fluid feeding means becomes stopped without intentionally providing a safety device such as a tempera-' ture fuse, thermostat and the like.
  • the heater of this invention when use in combination with means for feeding fluid through the heating element, is capable of changing the amount of heat radiation by varying the amount of fluid. It is possible, therefore to control a large electric power with the aid of a small electric power.
  • the amount of air on the order of 0.2 m /min can be fed by means of a fan driven by an electric motor of about 20 watts.
  • the control of the 20 Watts motor in its rotating speed ensures a control of the amount of heat radiation corresponding to electric power of 300 Watts which is about 15 times larger than 20 Watts.
  • the heating element according to the'invention it is important to make the surface-to-volume ratios'of the honeycomb structural body large. Even when the amount of passing air per unit volume of the heating element is the same, the larger the surface-to-volume ratio the larger the amount of heat radiation.
  • another heating element comprising a PTC ceramic article composed of a honeycomb structural body which is provided with a multiplicity of channels each square in cross section with a side of 0.195 cm and bounded by partition walls whose thickness is 0.03 cm.
  • the particulars of the PTC ceramic article are as follows.
  • the diameter is 4 cm, thickness (length of each channel) 1 cm, Tc--190C, the-surface-to-volume ratios about 16 cm /cm and the total surface area about 200 cm
  • This element is made of the same ceramic composition as those of the body from which the curve 101 was derived.
  • the heating element is provided at its surface, substantially perpendicular to the axial direction of each channel, with fohmic electrodes.
  • a curve 102 graphically illustrates the relation between the amount of air Q (m /min) fed into the channels of the above mentioned heating element at 20C and the amount of heat P (Watt) radiated from the heating element.
  • a comparison between the curves 101 and 102 clearly shows that the amount of heat radiation P (watt) shown by the curve 101 which is plotted when the surface-to-volume ratios are about 24 cm /cm is larger than that shown by the curve 102, which is plotted in the case of the surface-to-volume ratios are about 16 cm /cm
  • P watt
  • the frictional resistance of the fluid passing through a multiplicity of channels against the honeycomb structural body is proportional to the surface-to-volume ratios under the same configuration of the channels, so that the'surface-to-volume ratios should be determined in association with the kinds of fluid and means for feeding fluid through the heating element.
  • the surface-to-volume ratios it is preferable to determine the surface-to-volume ratios to a range from to 60 cm /cm with respect to the honeycomb structural body of the heating element according to the invention. Any structural body having some holes made, for example, by boring could neither make the thickness of the partition will bounding the holes substantially uniform, nor obtain the surface-to-volume ratios in the range of 10 to 60 cm /cm.
  • the Curie Temperature (Tc) of the PTC ceramic article of the heating element according to the invention is determined according to what purposes the heating element is used. If the heating element is used for a handy hair dryer, the heating element is restricted in its size.
  • the Curie Temperature (Tc) of the PTC ceramic article is made relatively high that a heating element small in volume can radiate a desired amount of heat.
  • the amount of heat radiation is associated not only with the Curie Temperature (Tc) of the PTC ceramic article, but also with the surface-tovolume ratios of the honeycomb structural body. It is preferable to make the Curie Temperature (Tc) 150 to 200C for the handy hair dryer.
  • the heating element according to the invention is used for a heater, a plurality of heating elements may be used according to the desired amount of heat radiation and to the other designs.
  • a customary heating element made of nickel-chrome wire, for example, may be included in a plurality of heating elements.
  • heating elements may electrically connected in series and/or in parallel with each other by techniques known in the art, it is-found to be preferable to connect in parallel from our investigation.
  • FIG. 6 is shown a preferred embodiment of the heating element according to the invention as applied to an air heater.
  • an air heater 10 comprising a heating element 1, and means for feeding fluid through the heating element 1 such as a fan 12 driven by a motor 11.
  • Such means can feed air into a multiplicity of channels of the heating element 1.
  • Means for feeding fluid through the heating element 1 is settled to be aligned with the channels of the honeycomb structural body of the heating element 1 and the assembly is enclosed in a housing 13.
  • arrangement and electrical connections are so designed that the heating element 1 is provided at its opposed surfaces substantially perpendicular to the axial direction of the channels with ohmic electrodes, and that the heating element 1 is sandwiched between a pair of terminal plates 14 and 15.
  • insulating spacers (not shown) are inserted-between these terminal plates 14, 15 and the housing 13 so as to electrically insulate the former from the latter.
  • the air heater 10 shown in FIG. 6 will operate as follows. If a switch 16 is turned ON, the fan 12 is rotated to suck air through an inlet opening 17 adapted to control the amount of air passing therethrough into the heating element 1. At the same time, electric current is supplied to the heating element 1 to bring it into a heat radiating condition, and as a result, the air passing through the channels is heated and blown out of the air heater 10.
  • the amount of heat radiated from the heating element 1 becomes small in the manner as described above.
  • a safety device such as a temperature fuse, thermostat and the like.
  • the air heater shown in FIG. 6 with or without any modification may be used as a hair dryer, domestic or industrial dryers, air towel, room heater and the like.
  • FIG. 7 is shown another preferred embodiment of the heating element according to the invention asressa of about 1,500 cm and ohmic electrodes pro-' vided on the side surfaces of the honeycomb structural body which is substantially parallel to the axial direction of each channel, and heat insulating material 21 covering the heating element 1 and enclosed in a housing 22.
  • a pipe 20 is also provided for feeding water to the channels.
  • the inlet pipe 19 is connected to, for example, a city water faucet (not shown) to feed water into-the pipe 20, so that the water passing through the multiplicity of channels is heated and flows out of an outlet pipe 23.
  • the liquid heater 18 shown inFlG. 7 will-operate as follows. If the switch 16 is turned ON, heat is radiated from the heating element 1 and hot water flows out of the outlet pipe 23. f a
  • the liquid heater 18 was fed with city water at 20C at a rate of about-l l/min and at the same time the pair of electrodes were applied "with voltage-of 240 volts, the city water heated to about 60C flowed from the outlet pipe 23.
  • the amount of heat radiation was 2.9 kilowatts.
  • the amount of heat radiated when the water supply was stopped became smaller than 100 watts, thereby involving no danger due to overheating of the heating element 1.
  • the electrical insulation of both the electrodes against an electric conductive liquid such as water may be effected by coating the heating element 1 as a whole, exclusive of the lead wires led out of the electrodes, with corrosion resistant materials such as fluorine resin (Teflon made by E. I. Du Pont de Nemours and Company, Polyflon, Daiflon and Neoflon made by Daikin Kogyo Co., Ltd. Osaka, Japan and the like), fluorine rubber (Viton made by Du Pont), silicone resin, silicone rubber, silicone varnish and the like.
  • fluorine resin Teflon made by E. I. Du Pont de Nemours and Company, Polyflon, Daiflon and Neoflon made by Daikin Kogyo Co., Ltd. Osaka, Japan and the like
  • fluorine rubber Viton made by Du Pont
  • silicone resin silicone rubber
  • silicone varnish silicone varnish
  • such coating can protect the heating element 1 from being corroded by corrosive liquid such as acids, alkalis and the like.
  • a pipe having a small diameter and made of anti-corrosion material such as stainless steel may be inserted into each of the channels of the heating element whereby the corrosive fluid can pass through the pipe without making contact with the inner surface of each of the channels.
  • the liquid heater shown in FIG. 7 is not provided with means for feeding fluid through the heating element, such as provided for the air heater shown in FIG. 6, but the city water pressure or gravity serves as means for feeding liquid through the heating element.
  • the liquid heater shown in FIG. 7 is connected to the city water faucet and adapted to heat the city water.
  • the liquid heater shown in FIG. 7 may also be used as a heater for drinks such as Japanese Sake and the like, and an oil preheater for heating liquid fuel and the like.
  • FIG. 8 a further preferred embodiment of the heating element according to the invention is shown as applied to a humidifier.
  • a humidifier 24 comprising a housing 26 enclosing water contained therein and a heating element 1.
  • a water absorbing mat 27 which is supported in a space above the water 25 and on which is disposed the heating element 1.
  • the water absorbing mat 27 is provided at its periphery with a bundle of fibers 28, such as woven cloth secured at its one end to the mat 27, the other end being immersed into the water 27.
  • the fiber bundle 28 and mat 27 permit the water to be supplied to the surface substantiallyperpendicular to the axial direction of the channels of the honeycomb structuralbody with the aid of capillary phenomenon of the fiber bundle 28 and the mat 27;
  • the humidifier shown in FIG. 8 ' will operate as follows; If the switch 16 is turned ON, the water in contact with one of the surfaces substantially perpendicular to the axial directionof the channels of the honeycomb structural body of the heating element 1 is heated by the heating element 1 and converted into steam which is exhausted from an opening 29 provided at the'top of the housing 26 and arranged above the heating element 1.
  • a heating element comprising a PTC ceramic article composed of a column shaped honeycomb structural body provided with a multiplicity of channels each square in cross section with a side of 0.125 cm and bounded by partition walls whose thickness is 0.02 cm, the honeycomb structural body having a diameter of 3.5 cm, a thickness (length of each channel) of 1 cm, Curie Temperature (Tc) of 190C, surface-to-volume ratios of about 24 cm /cm and total surface area of about 240 cm and ohmic electrodes provided on both surfaces substantially perpendicular to the axial direction of each channel. Water at 20C was treated by applying voltage of volts across the ohmic electrodes.
  • the water was evaporated at a rate of 4 cc/min.
  • the housing 26 is provided at its side wall with a window 30 through which can peep the change in liquid level and provided at its cover with an opening 31 through which is added liquid when the liquid level becomes lower than a desired level.
  • the humidifier shown in FIG. 8 with or without modifications may be used as a volatilizer, distillator, fractionator and the like for use with domestic or industrial water and any other liquids such as oil.
  • a heating element consisting essentially of:
  • a column-shaped honeycomb structural body of electrically conductive ceramic material said body having a multiplicity of substantially uniform parallel channels extending therethrough with each of said channels being bounded by a partition wall which is substantially uniform in thickness, said structural body also having a surface-to-volume ratio in the range of 10 to 60 cm /cm and having a positive temperature coefficient of electrical resistance;
  • a pair of ohmic electrodes mounted on the opposite surfaces of the body and in electrical contact therewith;
  • the heating element of claim 1 in which the ohmic electrodes are mounted on opposite surfaces substantially perpendicular to the axial direction of the channels.
  • a fluid heater which comprises:
  • a pair of ohmic electrodes mounted on the opposite surface of the body
  • the heater of claim 5 in which the surface to volume ratios are 10 to 40 cm /cm 8.
  • the heater of claim 7 in which the surface to volume ratios are 12 to 30 cm /cm UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3, 3 DATED DGC'B'ZiiDGl" 1.5, 1975 INVENTORKS) I Nada et a1 It is certified that error appears in the above-identified potent and that said Letters Patent are hereby corrected as shown below:

Abstract

An electric fluid heating element comprises a column-shaped honeycomb structural body of an electrically conductive cermaic material having a positive temperature coefficient of resistance. The body has a multiplicity of substantially uniform parallel channels extending therethrough with each of the channels being bounded by a partition wall which is substantially uniform in thickness. The body has a surface to volume ratio in the range of 10 to 60 cm2/cm3 and is selfcontrolling without the necessity of a safety device such as a fuse or thermostat. Ohmic electrodes are mounted on oppsoite surfaces of the body to supply heating current thereto. The heating element can be used as the heating means in an air heater, humidifier or liquid heater.

Description

4 United States Patent Wada et a1. Dec. 16, 1975 1 ELECTRIC FLUID HEATER AND 3,265,865 8/1966 Hager 219/300 x 2 21828 .1121: 212/221 u1 mg e a THEREFOR 3,691,346 9/1972 Dyre et al. 219/374 [75] Inventors: Shigetaka Wada, Kuwana; Noboru Yamamoto Nagoya, both of Japan FOREIGN PATENTS OR APPLICATIONS 512,667 10/1920 France .1 219/374 1 Asslgneel NGK Insulators, Nagoya, 932,558 7/1963 United Kingdom 219/300 Japan 499,074 l/l939 United Kingdom 219/382 [22] Filed: Mar. 4, 1974 Primary Examiner-A. Bartls [21] Appl. No.: 447,513
[57] ABSTRACT [30] Foreign Apphcatlon Pnonty Data An electric fluid heating element comprises a column- Mar. 9, Japan haped honeycomb tructural of an electrically conductive cermaic material having a positive temper- U-S- Clature oefficient of resistance The has a multi- 3 1 5 3355/22 252/520 plicity of substantially uniform parallel channels ex- [51] Cum H053 3/14; HOlC 7/02; F24H 1/10; tending therethrough with each of the channels being F24H 3/04 bounded by a partition wall which is substantially uni- [58] Field of Search 219/381, 382, 374376, f in thickness The body has a Surface to volume 23, ratio in the range of 10 to 60 cm /cm and is selfcon- 362, 58; 252/518 520 trolling without the necessity of a safety device such as a fuse or thermostat. Ohmic electrodes are mounted [56] References Cited on oppsoite surfaces of the body to supply heating UNITED STATES PATENTS current thereto. The heating element can be used as 927,173 7/1909 Schluter 219/381 the heating means in an air heater, humidifier of liquid 1,334,809 3/1920 Simon et a1. 219/381 UX heaten 3,163,841 12/1964 Willett 219/374 UX 8 Cl 8 D F. 3,244,860 4/1966 Lindley 219/382 x rawmg gums OHMIC ELECTRODE PTC CERAMIC MATERIAL OHMIC ELECTRODE sheet 1 of5 3,927,300
U.S. Patent Dec. 16, 1975 OHMIC ELECTRODE PTC CERAMIC MATERIAL ommc ELECTRODE PTC CERAMIC MATERIAL OHMIC ELECTRODE U.S. Patent Dec. 16, 1975 Sheet20f5 3,927,300
m? SURFACE TO VOLUME RATIO ABOUT 24 CM2/CM3 E 200 \SURFACE T0 VOLUME RATIO Q ABOUT l6 cm /cm 0./ 0:2 0:5 014 0'5 O(m /min) Sheet 3 of 5 3,927,300
US. Patent Dec. 16, 1975 US. Patent Dec. 16,1975 Sheet40f5 3,927,300
US. Patent Dec. 16,1975 Sheet50f5 3,927,300
ELECTRIC FLUID HEATER AND RESISTANCE HEATING ELEMENT THEREFOR BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to heating elements, and more particularly to a heating element comprising a ceramic article having a positive temperature coefficient of electric resistance (hereinafter referred to as PTC ceramic article). The element is composed of a honeycomb structural body and includes a pair of ohmic electrodes. The element is adapted to generate a large amount of heat radiation with a small volume without any risk of overheating and breaking. The invention also includes a heater comprising this heating element which is particularly useful as an air heater, dryers inclusive of a hair dryer, air towel, liquid heater, humidifier, volatilizer and the like.
In the in the remainder of the specification, the term honeycomb structural body shall be understood to mean a structural body having a multiplicity of channels extending therethrough and generally parallel to each other and having high surface-to-volume ratios.
2. Description of the Prior Art Heretofore, it has been the common practice to use metals and ceramics having a negative or a positive temperature coefficient of electric resistance.
Metal has a small specific resistance and hence is commonly used in linear form in the heating element. If such heating element is used, for example, in a hair dryer and a fan is used to feed air therethrough, and suction opening is clogged, the metal constituting the heating element becomes overheated, causing a fire. Eventually there is a risk of the metal being oxidized and broken.
The ceramic article having a negative temperature coefficient of electric resistance, is commonly formed into a rod having a pair of ohmic electrodes mounted thereon and used as a heating element. A ceramic article for example, silicon carbide, in order to generate a given amount of heat radiation without overheating the heating element per se, a number of these heating elements must be used simultaneously. Alternatively temperature control means must be used, and as a result, the assembly becomes complex in construction and/or there is a risk of the heating element being broken. Thus, such a heating element is not suitable for use with domestic heaters.
In addition, a PTC ceramic article made of semiconductive barium titanate has commonly been formed into a disc-shaped pellet on which are mounted a pair of ohmic electrodes for use as a heating element. Such kind of heating element, however, can only generate the amount of heat radiation corresponding to a few watts from one heating element. As a result, in order to cause it to generate the amount of heat radiation corresponding to several watts, a large heat radiating plate must be added thereto. Thus, this kind of heating element is subjected to restrictions in its construction. Moreover, if it is desired to obtain a large amount of heat radiation with the aid of a high electric power of, for example, more than 1 KW, a number of heating elements each including the above described heat radiating plate are required. The use of the measures described is extremely uneconomical and results in considerable constructional disadvantage as that it could not be applied to domestic heat radiators.
In addition, a heating element comprising a cylindrical PTC ceramic article which is provided at its inner and outer surfaces with ohmic electrodes has been known. If this heating element has its surface area of about 1,000 cm in order to obtain a sufficiently large amount of heat radiation, for a the diameter of 5 cm it is necessary to make the length longer than 30 cm. As a result, the volume of the heating element becomes too large as compared with the volume of the customary type of heating element. Thus, the mechanical strength of the heating element becomes lowered and this type of heating element has not achieved any importance in actual practice.
SUMMARY OF THE INVENTION The invention is based upon recognition of the fact that a PTC ceramic article composed of a honeycomb structural body provides a heating element which is small in volume and which can generate a large amount of heat radiation without overheating and breaking.
The invention thus provides a heater comprising the above described heating element and particularly useful in air heater, dryers inclusive of a hair dryer, air towel, liquid heater, humidifer, volatilizer and the like.
The principal object of the invention, therefore, is to provide a heating element comprising a PTC ceramic article composed of a honeycomb structural body.
Another object of the invention is to provide a heater, which comprises a heating element comprising a PTC ceramic article composed of a honeycomb structural body and particularly useful as an air heater, dryers inclusive of a hair dryer, air towel, liquid heater, humidifer, volatilizer and the like.
A further object of the invention is to provide various types of heaters each having a preferable construction.
A still further object of the invention is to provide a method of producing a heating element comprising a PTC ceramic article composed of a honeycomb structural body and to provide a method of forming ohmic electrodes therefor.
Other objects, advantages and capabilities of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings showing only a preferred embodiment of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a preferred embodiment of the heating element according to the invention;
FIG. 2 is a section along line IIII in FIG. 1;
FIG. 3 is a perspective view of another embodiment of the heating element according to the invention;
FIG. 4 is a section along line IV-IV in FIG. 3;
FIG. 5 is a graph which illustrates the relation between the amount of heat radiated from the heating element according to the invention and the amount of air fed to the heating element;
FIG. 6 is a perspective view of a preferred embodiment of an air heater employing the heating element according to the invention, a part being broken away for clarity;
FIG. 7 is a perspective view of a preferred embodiment of a liquid heater employing the heating element according to the invention, a part being broken away for clarity; and
FIG. 8 is a perspective view of a preferred embodiment of a humidifier employing the heating element according to the invention, a part being broken away 3 for clarity.
DESCRIPTION OF THE PREFERRED EMBODIMENT The preferred embodiments of the invention will now be described in greater detail with reference to the accompanying drawings.
In FIGS. 1 and 2 a heating element 1 is shown according to the invention which is composed of a honeycomb structural body provided with a multiplicity of channels 2 extending therethrough and generally parallel to each other. Each of these channels 2 is bounded by a partition wall 3 which is substantially uniform in thickness. The honeycomb structural body constructed as above described insures extremely high surface-tovolume ratios. The partition walls 3 are provided at their opposed end surfaces substantially perpendicular to theaxial direction of the channels 2 with a pair of ohmic electrodes 4, 5, respectively. The thickness of both the partition wall 3 and ohmic electrodes 4, 5 is shown in enlarged scale in FIGS. 1 and 2 for clarity.
A preferred method of producing the heating element according to the invention will now be described.
BaCo TiO SiO and La O were weighed with mole ratios of l.00:1.02:0.02:0.003, respectively, mixed in a ball mill with rubber lining for 12 hours, dried and calcined at 1,100C for 3 hours. The calcined raw material was roughly pulverized by a double roll crusher with alumina rolls and then finely pulverized in a ball mill with rubber lining for 6 hours. The finely pulverized particles were passed through a screen with a mesh of 149 microns and then dried. To 100 parts by weight of the dried powders were added 4 parts by weight of methyl cellulose, 16.5 cc of 12% polyvinyl alcohol water solution, 3 parts by weight of polyethylene glycol and 8.5 parts by weight of water. The mixture was well blended in a kneader and then subjeted to de-ain'ng while blending with the aid of a de-airing pug mill. The product thus obtained was extruded from the de-airing pug mill through a honeycomb structural body forming nozzle so as to form a green body composed of a honeycomb structural body. The green body thus obtained was dried by means of a freeze drying method using dry ice and then fired in a standard electric furnace using silicon carbide heaters at l,350 C for 2 hours. A column shaped honeycomb structural body having a diameter of 4 cm and a thickness of 1 cm (length of channels) and provided with a multiplicity of channels each square in section having each side of 0.195 cm and bounded by a partition wall having a thickness of 0.03 cm was thereby obtained. The honeycomb structural body has surface-to-volume ratios of about 16 cm /cm and total surface area of about 200 cm Ohmic electrodes were provided for each end surface substantially perpendicular to the axial direction of the channel, thus completing a heating element.
The, ceramic compositions are not restricted to the above described ceramic composition and any other customary compositions which can obtain a positive temperature coefficient of electric resistance may also be used. Examples of such ceramic compositions are those described in U.S. Pat. Application Ser. No. 431,397 filed on Jan. 7, 1974 which is a continuationin-part of Application Ser. No. 256,368 filed on May 24, 1972; now abandoned and those described in U.S. Pat. No. 2,981,699, No. 3,373,120 and No. 3,441,517, respectively.
In addition, the honeycomb structural body may be formed by any methods other than the above described extrusion method. Examples of these methods are a press method, a method of producing a bundle of a number of green ceramic pipes and then firing the bundle, or a method of forming a honeycomb structural body comprising coating ceramic raw material particles suspended in an organic binder on the surface of sheet of paper and the like, corrugating the coated sheet of paper and the like, accumulating the corrugated sheet of paper and the like and firing the accumulated sheet of paper and the like as disclosedin U.S. Pat. No. 3,112,184.
In addition, the sectional configuration of the channels may be formed into any configurations other than square as shown in FIGS. 1 and 3, such, for example, as triangular, hexagonal or any other polygonal, circular and the like sectional configurations (not shown).
The outer configuration of the honeycomb structural body constituting the essential part of the heating element is shown as columnar in shape in FIG. 1 and rectangular parallelepipe in shape in FIG. 3, but if necessary the outer configuration of the honeycomb structural body may be of cube, polygonal columnar in shape (not shown).
In the embodiment shown in FIGS. 1 and 2, the honeycomb structural body is provided at its each end surface substantially perpendicular to the axial direction of the channels with the ohmic electrode. But, these ohmic electrodes may be mounted on any positions other than end surfaces of the honeycomb structural body.
For example, the honeycomb structural body may be provided at its each side surface 6, 7 which is substantially parallel to the axial direction of the channels and opposed to each other with a pair of electrodes 8, 9 as shown in FIGS. 3 and 4. Whether the ohmic electrodes should be mounted on the surfaces substantially perpendicular to the axial direction of the channels or mounted on the outer surfaces of the honeycomb structural body substantially parallel to the axial direction of the channels may be determined depending on the outer configuration of the honeycomb structural body its mechanical strength, the purpose to which the honeycomb structural body is used, the amount of heat radiation, the restriction in design of the heater into which the honeycomb structural body is incorporated as a heating element and any other various conditions.
In FIGS. 2 and 4, the thickness of the partition wall 3 and ohmic electrodes 8, 9 is shown in enlarged scale for clarity.
The ohmic electrodes may be formed on the outer surfaces of honeycomb structural body by means of such a common method as those described, for example, in U.S. Pat. No. 3,676,211, British vPat. No. 1,252,490, Electrodes for Ceramic Barium Titanate Type Semiconductors by H. M. Landis, Journal of Applied Physics, 1965, Vol. 36, Nos. 6, pages 2,000 to 2,001 and the like. But, it is preferable to form the ohmic electrodes on the outer surfaces of the honeycomb structural body by means of the following method in order to produce the heating element according to the invention.
' When forming the ohmic electrodes on the surfaces substantially perpendicular to the axial direction of the channels as shown in FIGS. 1 and 2, it is preferable to use the silver paste baking method, the aluminum hot spraying method or electroless nickel plating method.
When forming the ohmic electrodes on the outer surfaces of the honeycomb structural body substantially parallel to the axial direction of the channels as shown in FIGS. 3 and 4, it is preferable to use the aluminum hot spraying method. These methods will now be described, respectively.
The silver paste baking method comprises coating silver paste on the ceramic article by means of a screen printing method and-baking the coated surfaces. However, silver paste having the typical composition used with a customary condenser, for example, Silver Paste 7095 made by E. I. Du Pont de Nemours and Company, could not provide the ohmic electrodes which are well suited for the PTC ceramic article. Such a disadvantage can be obviated by the use of a silver paste containing indium. On the other hand, such indium containing silver paste is expensive.
The silver paste developed by the invention consists of silver and zinc with a range of weight ratios of 2:1 to 40:1, glass powder, and an organic solvent. This silver paste after coating is baked at a temperature of 420 to 550C.
It is preferable to apply such silver paste baking method to a PTC ceramic article whose Curie Temperature (Tc) is lower than a temperature of about 150C. This is because of the fact that silver is subjected to surface diffusion at a temperature higher than 200C so that there is a risk of the silver coated surfaces being shortcircuited to each other at a temperature higher than 200C after long use.
The aluminum hot spraying method is capable of providing electrodes which can eliminate the above described difficult problem which has been encountered with the silver paste baking method. In the aluminum hot spraying method, it has been the common practice to spray aluminum against surfaces of a ceramic article in a direction substantially perpendicular thereto so as to expedite adherence of aluminum to those surfaces, as described in the US. Pat. No. 3,676,211. If aluminum is sprayed from a direction perpendicular to the surfaces which is substantially perpendicular to the axial direction of the channels of the honeycomb structural body, that is, from the direction substantially parallel to the axial direction of the channels, aluminum becomes adhered 'to the inner wall surfaces of all of the channels, thereby shortcircuiting the sprayed surfaces. In order to obviate such disadvantage, the invention provides an improved method wherein aluminum is sprayed in a direction inclined from the surfaces which is substantially perpendicular to the axial direction of the channels by an angle of to 60, preferably, to 45.
In the electroless nickel plating method, the ceramic article is plated with nickel as a whole. Such method, therefore, could not be applied to the invention. Thus, the invention provides an improved electroless nickel plating method by which nickel is plated on surfaces only substantially perpendicular to the axial direction of the channels and which comprises immersing the honeycomb structural body into silicon resin or wax, for example,,to mask the total body with the resin or wax, grinding the surfaces substantially perpendicular to the axial direction of the channels to remove the mask, subjecting activating treatment only to the mask removed surface, and immersing the body into nickel salts solution to form ohmic electrodes on the surfaces only substantially perpendicular to the axial direction of the channels. In this method, it is important to mask the honeycomb structural body with the resin or wax such that each channel is maderound in shape at its corner edges. These masked round corner edge portions can prevent a penetration of the activating treating liquid into the channels due to surface tension and hence prevent an electroless plating against the inner walls of the channels, thereby preventing shortcircuit across the electrodes.
A heater employing the heating element according to the invention will now be described in greater detail.
As an example, use is made of a heating element comprising a PTC ceramic article composed of a honeycomb structural body which is provided with a multiplicity of channels each square in cross section with a side of 0.125 cm and bounded by partition walls whose thickness is 0.02 cm. The particulars of the PTC ceramic article are as follows. The diameter is 4 cm, thickness (length of each channel) 1 cm, Tc=lC, the surface-to-volume ratios about 24 cm /cmi and the total surface area about 300 cm The heating element is provided at its surface substantially perpendicular to the axial direction of each channel with ohmic electrodes.
In FIG. 5, a curve 101 graphically illustrates the relation between the amount of air Q (m /min) fed into the channels of the heating element at 20C and the amount of heat P (watt) radiated from the above mentioned heating element. As seen from the curve 101, the amount of heat radiation is about 230 watts when the amount of air fed is 0.1 m /min, whereas if the amount of air fed is increased to 0.5 m /min which is 5 times larger than 0.1 m /min, the amount of heat radiation becomes also increased to about 450 watts. If the amount of air fed is substantially zero, that is, if the forced draft is stopped and use is made of natural convection air caused by the heat radiated from the heating element, the amount of heat radiation becomes only 20 watts.
As described above, when various kinds of fluid inclusive of air pass'through a multiplicity of channels of the heating element according to invention, the heating element with a small volume can radiate a large amount of heat. Thus, a heater comprising the heating element according to the invention and means for feeding fluid through the heating element such, for example, as'a fan, pump, water pressure of city water and the like can prevent an overheating of the heating element when the fluid feeding means becomes stopped without intentionally providing a safety device such as a tempera-' ture fuse, thermostat and the like.
In addition, in the heater of this invention (when use in combination with means for feeding fluid through the heating element) is capable of changing the amount of heat radiation by varying the amount of fluid. It is possible, therefore to control a large electric power with the aid of a small electric power.
For example, if use is made of air as fluid, the amount of air on the order of 0.2 m /min can be fed by means of a fan driven by an electric motor of about 20 watts. As a result, as seen from FIG. 5, the control of the 20 Watts motor in its rotating speed ensures a control of the amount of heat radiation corresponding to electric power of 300 Watts which is about 15 times larger than 20 Watts.
In the heating element according to the'invention, it is important to make the surface-to-volume ratios'of the honeycomb structural body large. Even when the amount of passing air per unit volume of the heating element is the same, the larger the surface-to-volume ratio the larger the amount of heat radiation. For comparison, use is made of another heating element comprising a PTC ceramic article composed of a honeycomb structural body which is provided with a multiplicity of channels each square in cross section with a side of 0.195 cm and bounded by partition walls whose thickness is 0.03 cm. The particulars of the PTC ceramic article are as follows. The diameter is 4 cm, thickness (length of each channel) 1 cm, Tc--190C, the-surface-to-volume ratios about 16 cm /cm and the total surface area about 200 cm This element is made of the same ceramic composition as those of the body from which the curve 101 was derived. The heating element is provided at its surface, substantially perpendicular to the axial direction of each channel, with fohmic electrodes. In FIG. 5, a curve 102 graphically illustrates the relation between the amount of air Q (m /min) fed into the channels of the above mentioned heating element at 20C and the amount of heat P (Watt) radiated from the heating element. A comparison between the curves 101 and 102 clearly shows that the amount of heat radiation P (watt) shown by the curve 101 which is plotted when the surface-to-volume ratios are about 24 cm /cm is larger than that shown by the curve 102, which is plotted in the case of the surface-to-volume ratios are about 16 cm /cm The frictional resistance of the fluid passing through a multiplicity of channels against the honeycomb structural body is proportional to the surface-to-volume ratios under the same configuration of the channels, so that the'surface-to-volume ratios should be determined in association with the kinds of fluid and means for feeding fluid through the heating element. It is preferable to determine the surface-to-volume ratios to a range from to 60 cm /cm with respect to the honeycomb structural body of the heating element according to the invention. Any structural body having some holes made, for example, by boring could neither make the thickness of the partition will bounding the holes substantially uniform, nor obtain the surface-to-volume ratios in the range of 10 to 60 cm /cm The Curie Temperature (Tc) of the PTC ceramic article of the heating element according to the invention is determined according to what purposes the heating element is used. If the heating element is used for a handy hair dryer, the heating element is restricted in its size. As a result, the Curie Temperature (Tc) of the PTC ceramic article is made relatively high that a heating element small in volume can radiate a desired amount of heat. The amount of heat radiation is associated not only with the Curie Temperature (Tc) of the PTC ceramic article, but also with the surface-tovolume ratios of the honeycomb structural body. It is preferable to make the Curie Temperature (Tc) 150 to 200C for the handy hair dryer.
As will be described later, if the heating element according to the invention is used for a heater, a plurality of heating elements may be used according to the desired amount of heat radiation and to the other designs. In this case, a customary heating element made of nickel-chrome wire, for example, may be included in a plurality of heating elements.
.Though these heating elements may electrically connected in series and/or in parallel with each other by techniques known in the art, it is-found to be preferable to connect in parallel from our investigation.
In FIG. 6 is shown a preferred embodiment of the heating element according to the invention as applied to an air heater.
Referring to FIG. 6, an air heater 10 comprising a heating element 1, and means for feeding fluid through the heating element 1 such as a fan 12 driven by a motor 11. Such means can feed air into a multiplicity of channels of the heating element 1. Means for feeding fluid through the heating element 1 is settled to be aligned with the channels of the honeycomb structural body of the heating element 1 and the assembly is enclosed in a housing 13. In the present embodiment, arrangement and electrical connections are so designed that the heating element 1 is provided at its opposed surfaces substantially perpendicular to the axial direction of the channels with ohmic electrodes, and that the heating element 1 is sandwiched between a pair of terminal plates 14 and 15. It is a matter of course that insulating spacers (not shown) are inserted-between these terminal plates 14, 15 and the housing 13 so as to electrically insulate the former from the latter.
The air heater 10 shown in FIG. 6 will operate as follows. If a switch 16 is turned ON, the fan 12 is rotated to suck air through an inlet opening 17 adapted to control the amount of air passing therethrough into the heating element 1. At the same time, electric current is supplied to the heating element 1 to bring it into a heat radiating condition, and as a result, the air passing through the channels is heated and blown out of the air heater 10.
Between ON and OFF, a state which the fan 12 continues its air feeding operation and the heating element 1 stops its heating operation may be employed.
During heating of the heating element 1 by the current supplied thereto, even if the fan 12 becomes stopped or the air inlet opening 17 gets cloggedby a towel, a curtain or the like, to cause no air to pass through the multiplicity of channels of the heating element 1, the amount of heat radiated from the heating element 1 becomes small in the manner as described above. As a result, there is no risk of the heating element 1 being overheated or of a fire being caused without intentionally providing a safety device such as a temperature fuse, thermostat and the like. The air heater shown in FIG. 6 with or without any modification may be used as a hair dryer, domestic or industrial dryers, air towel, room heater and the like.
In FIG. 7 is shown another preferred embodiment of the heating element according to the invention as aparea of about 1,500 cm and ohmic electrodes pro-' vided on the side surfaces of the honeycomb structural body which is substantially parallel to the axial direction of each channel, and heat insulating material 21 covering the heating element 1 and enclosed in a housing 22. In this embodiment, a pipe 20 is also provided for feeding water to the channels. The inlet pipe 19 is connected to, for example, a city water faucet (not shown) to feed water into-the pipe 20, so that the water passing through the multiplicity of channels is heated and flows out of an outlet pipe 23.
. The liquid heater 18 shown inFlG. 7 will-operate as follows..If the switch 16 is turned ON, heat is radiated from the heating element 1 and hot water flows out of the outlet pipe 23. f a
If the liquid heater 18 was fed with city water at 20C at a rate of about-l l/min and at the same time the pair of electrodes were applied "with voltage-of 240 volts, the city water heated to about 60C flowed from the outlet pipe 23. In this case, the amount of heat radiation was 2.9 kilowatts. The amount of heat radiated when the water supply was stopped became smaller than 100 watts, thereby involving no danger due to overheating of the heating element 1.
The electrical insulation of both the electrodes against an electric conductive liquid such as water may be effected by coating the heating element 1 as a whole, exclusive of the lead wires led out of the electrodes, with corrosion resistant materials such as fluorine resin (Teflon made by E. I. Du Pont de Nemours and Company, Polyflon, Daiflon and Neoflon made by Daikin Kogyo Co., Ltd. Osaka, Japan and the like), fluorine rubber (Viton made by Du Pont), silicone resin, silicone rubber, silicone varnish and the like.
In addition, such coating can protect the heating element 1 from being corroded by corrosive liquid such as acids, alkalis and the like.
Alternatively, as means for preventing the heating element 1 from being corroded by the corrosive fluid, provision may be made for a pipe having a small diameter and made of anti-corrosion material such as stainless steel and this pipe may be inserted into each of the channels of the heating element whereby the corrosive fluid can pass through the pipe without making contact with the inner surface of each of the channels.
The liquid heater shown in FIG. 7 is not provided with means for feeding fluid through the heating element, such as provided for the air heater shown in FIG. 6, but the city water pressure or gravity serves as means for feeding liquid through the heating element. In addition, the liquid heater shown in FIG. 7 is connected to the city water faucet and adapted to heat the city water. But, the liquid heater shown in FIG. 7 may also be used as a heater for drinks such as Japanese Sake and the like, and an oil preheater for heating liquid fuel and the like.
In FIG. 8 a further preferred embodiment of the heating element according to the invention is shown as applied to a humidifier.
Referring to FIG. 8, a humidifier 24 comprising a housing 26 enclosing water contained therein and a heating element 1. In the present embodiment, it is important that one of the surfaces substantially perpendicular to the axial direction of the channels of the honeycomb structural body is always in contact with the water 25. In order to make one of the surfaces substantially perpendicular to the axial direction of the channels of the honeycomb structural body always contact with the water 25, provision is made for a water absorbing mat 27 which is supported in a space above the water 25 and on which is disposed the heating element 1. The water absorbing mat 27 is provided at its periphery with a bundle of fibers 28, such as woven cloth secured at its one end to the mat 27, the other end being immersed into the water 27. The fiber bundle 28 and mat 27 permit the water to be supplied to the surface substantiallyperpendicular to the axial direction of the channels of the honeycomb structuralbody with the aid of capillary phenomenon of the fiber bundle 28 and the mat 27;
The humidifier shown in FIG. 8 'will operate as follows; If the switch 16 is turned ON, the water in contact with one of the surfaces substantially perpendicular to the axial directionof the channels of the honeycomb structural body of the heating element 1 is heated by the heating element 1 and converted into steam which is exhausted from an opening 29 provided at the'top of the housing 26 and arranged above the heating element 1.
In the present embodiment, use was made of a heating element comprising a PTC ceramic article composed of a column shaped honeycomb structural body provided with a multiplicity of channels each square in cross section with a side of 0.125 cm and bounded by partition walls whose thickness is 0.02 cm, the honeycomb structural body having a diameter of 3.5 cm, a thickness (length of each channel) of 1 cm, Curie Temperature (Tc) of 190C, surface-to-volume ratios of about 24 cm /cm and total surface area of about 240 cm and ohmic electrodes provided on both surfaces substantially perpendicular to the axial direction of each channel. Water at 20C was treated by applying voltage of volts across the ohmic electrodes. The water was evaporated at a rate of 4 cc/min. The housing 26 is provided at its side wall with a window 30 through which can peep the change in liquid level and provided at its cover with an opening 31 through which is added liquid when the liquid level becomes lower than a desired level.
The humidifier shown in FIG. 8 with or without modifications may be used as a volatilizer, distillator, fractionator and the like for use with domestic or industrial water and any other liquids such as oil.
While several examples have been herein disclosed, it is obvious that various changes can be made without departing from the spirit and scope of the invention as set forth in the appended claims. Further, it is to be understood that all matter hereinbefore set forth is to be interpreted as illustrative and not in a limiting sense.
What is claimed is:
l. A heating element consisting essentially of:
a. a column-shaped honeycomb structural body of electrically conductive ceramic material, said body having a multiplicity of substantially uniform parallel channels extending therethrough with each of said channels being bounded by a partition wall which is substantially uniform in thickness, said structural body also having a surface-to-volume ratio in the range of 10 to 60 cm /cm and having a positive temperature coefficient of electrical resistance;
b. a pair of ohmic electrodes mounted on the opposite surfaces of the body and in electrical contact therewith;
0. Means for feeding fluid through said channels.
2. The heating element of claim 1 in which the ohmic electrodes are mounted on opposite surfaces substantially perpendicular to the axial direction of the channels.
3. The heating element of claim I in which the surface to volume ratios are 10 to 40 cm /cm 4. The heating element of claim 3 in which the surface to volume ratios are 12 to 30 cm /cm 5. A fluid heater which comprises:
b. A pair of ohmic electrodes mounted on the opposite surface of the body;
c. Means for feeding fluid through said channels.
6. The heater of claim 5 in which the ohmic electrodes are mounted on the opposite end surfaces substantially parallel to the axial direction of the channels.
7. The heater of claim 5 in which the surface to volume ratios are 10 to 40 cm /cm 8. The heater of claim 7 in which the surface to volume ratios are 12 to 30 cm /cm UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3, 3 DATED DGC'B'ZiiDGl" 1.5, 1975 INVENTORKS) I Nada et a1 It is certified that error appears in the above-identified potent and that said Letters Patent are hereby corrected as shown below:
Delete column 1 line 5 sai fi channels.]
r, do} I-ieans for feeding fluid through Signed and Sealed this Arrest:
RUTH C. MASON C. MARSHALL DANN Amnrrrrrg Officer (mnmissimu'r nflau'nrr umi Trarlvmurkx UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT 3, 2 i73- DATED DQ681108? 1.5:, 1f??? INVENTORKS) i r ggt a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below Delete column 1-4,), line 59, {(CF t'leans fer fluid through said channelsj Signed and Scaled this eleventh Of May1976 [SEAL] Arrest.
RUTH c. MASON c. MARSHALL DANN Arrr'srmg ()jji'cer (ummr'xsimu'r ujlarenrs and Trademarks

Claims (8)

1. A heating element consisting essentially of: a. a column-shaped honeycomb structural body of electrically conductive ceramic material, said body having a multiplicity of substantially uniform parallel channels extending therethrough with each of said channels being bounded by a partition wall which is substantially uniform in thickness, said structural body also having a surface-to-volume ratio in the range of 10 to 60 cm2/cm3 and having a positive temperature coefficient of electrical resistance; b. a pair of ohmic electrodes mounted on the opposite surfaces of the body and in electrical contact therewith; c. Means for feeding fluid through said channels.
2. The heating element of claim 1 in which the ohmic electrodes are mounted on opposite surfaces substantially perpendicular to the axial direction of the channels.
3. The heating element of claim 1 in which the surface to volume ratios are 10 to 40 cm2/cm3.
4. The heating element of claim 3 in which the surface to volume ratios are 12 to 30 cm2/cm3.
5. A fluid heater which comprises: a. a column-shaped body of electrically conductive ceramic material said ceramic body having a multiplicity of substantially uniforms parallel channels extending therethrough with each of said channels being bounded by a partition wall which is substantially uniform in thickness, said body having a surface to volume ratio in the range of 10 to 60 cm2/cm3, said ceramic material having a positive temperature coefficient of electrical resistance; b. A pair of ohmic electrodes mounted on the opposite surface of the body; c. Means for feeding fluid through said channels.
6. The heater of claim 5 in which the ohmic electrodes are mounted on the opposite end surfaces substantially parallel to the axial direction of the channels.
7. The heater of claim 5 in which the surface to volume ratios are 10 to 40 cm2/cm3.
8. The heater of claim 7 in which the surface to volume ratios are 12 to 30 cm2/cm3.
US447513A 1973-03-09 1974-03-04 Electric fluid heater and resistance heating element therefor Expired - Lifetime US3927300A (en)

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Cited By (97)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4032752A (en) * 1975-09-03 1977-06-28 Ngk Insulators, Ltd. Heating elements comprising a ptc ceramic article of a honeycomb structure composed of barium titanate
DE2752752A1 (en) * 1976-11-26 1978-06-01 Ngk Insulators Ltd PROCESS FOR MANUFACTURING BODIES WITH A HONEYCOMB STRUCTURE FROM CERAMIC MATERIALS OF THE BARIUM TITANATE GROUP WITH POSITIVE TEMPERATURE RESISTANCE COEFFICIENTS
US4107515A (en) * 1976-09-09 1978-08-15 Texas Instruments Incorporated Compact PTC resistor
US4108125A (en) * 1976-09-10 1978-08-22 Texas Instruments Incorporated High efficiency early fuel evaporation carburetion system
US4123851A (en) * 1975-07-18 1978-11-07 Hitachi, Ltd. Clothes drier
US4141327A (en) * 1976-09-09 1979-02-27 Texas Instruments Incorporated Early fuel evaporation carburetion system
DE2904276A1 (en) * 1978-02-06 1979-08-16 Ngk Insulators Ltd BARIUM TITANATE HOMOLOGOUS CERAMIC MATERIALS
DE2905905A1 (en) * 1978-02-22 1979-08-23 Tdk Electronics Co Ltd COMB-SHAPED HEATING ELEMENT
US4177778A (en) * 1976-07-29 1979-12-11 Nippondenso Co., Ltd. Carburetors with heating device
US4180901A (en) * 1976-09-09 1980-01-01 Texas Instruments Incorporated Compact PTC resistor
US4198669A (en) * 1976-09-09 1980-04-15 Texas Instruments Incorporated Compact PTC resistor
US4212275A (en) * 1976-11-05 1980-07-15 Nissan Motor Company, Limited Carburetor
US4245146A (en) * 1977-03-07 1981-01-13 Tdk Electronics Company Limited Heating element made of PTC ceramic material
US4264888A (en) * 1979-05-04 1981-04-28 Texas Instruments Incorporated Multipassage resistor and method of making
DE2946799A1 (en) * 1979-11-20 1981-05-21 Siemens AG, 1000 Berlin und 8000 München Heating element with PTC honeycomb body - made from small extruded ceramic pipes sintered together and having current supply points on opposite faces
US4279234A (en) * 1979-01-12 1981-07-21 Texas Instruments Incorporated Early fuel evaporation of carburetion system
US4316077A (en) * 1975-12-31 1982-02-16 Texas Instruments Incorporated Elastic hair dryer having selectively variable air output temperature
US4369029A (en) * 1979-03-29 1983-01-18 Kernforschungsanlage Julich Gmbh Ceramic recuperator and method for the heating of combustion air
US4401879A (en) * 1981-02-20 1983-08-30 Texas Instruments Incorporated Self-regulating electrical resistance heater and fuel supply system using the heater
US4447706A (en) * 1979-03-27 1984-05-08 Danfoss A/S Nozzle assembly with integrated PTC heater for prewarming fuel oil
US4598686A (en) * 1985-03-28 1986-07-08 Casco Products Inc. Fuel vapor recovery system for automotive vehicles
US4629864A (en) * 1983-12-23 1986-12-16 Black & Decker, Inc. Hot air gun
US4654510A (en) * 1979-10-11 1987-03-31 Tdk Electronics Co., Ltd. PTC heating apparatus
US4717401A (en) * 1986-09-24 1988-01-05 Casco Products Corporation Fuel vapor recovery system
US4721846A (en) * 1986-07-02 1988-01-26 Casco Products Corporation Canister heater with PTC wafer
US4736718A (en) * 1987-03-19 1988-04-12 Linder Henry C Combustion control system for internal combustion engines
US4855571A (en) * 1988-01-29 1989-08-08 Industrial Technology Research Institute Positive temperature coefficient ceramic heating element for heating a fluid
US4886956A (en) * 1988-10-26 1989-12-12 Gte Products Corporation Method of electroding PTC heaters
US5206476A (en) * 1991-09-30 1993-04-27 General Motors Corporation Supplementary automobile duct heater
US5266278A (en) * 1990-07-06 1993-11-30 Ngk Insulators, Ltd. Honeycomb heater having integrally formed electrodes and/or integrally sintered electrodes and method of manufacturing such honeycomb heater
US5461695A (en) * 1992-08-05 1995-10-24 Paul Ritzau Pari-Werk Gmbh Nebulizing assembly with heating equipment
US5513296A (en) * 1994-06-08 1996-04-30 Holmes Products Corp. Air heater with angled PTC heaters producing diverging heated airflow
US5586214A (en) * 1994-12-29 1996-12-17 Energy Convertors, Inc. Immersion heating element with electric resistance heating material and polymeric layer disposed thereon
US5634457A (en) * 1992-09-30 1997-06-03 Nippon Chemical Plant Consultant Co., Ltd. Gas heating apparatus
US5758826A (en) * 1996-03-29 1998-06-02 Siemens Automotive Corporation Fuel injector with internal heater
US5835679A (en) * 1994-12-29 1998-11-10 Energy Converters, Inc. Polymeric immersion heating element with skeletal support and optional heat transfer fins
EP0919154A2 (en) * 1997-11-29 1999-06-02 Samsung Electronics Co., Ltd. Hair dryer
US5930459A (en) * 1994-12-29 1999-07-27 Energy Converters, Inc. Immersion heating element with highly thermally conductive polymeric coating
US6102303A (en) * 1996-03-29 2000-08-15 Siemens Automotive Corporation Fuel injector with internal heater
US6109543A (en) * 1996-03-29 2000-08-29 Siemens Automotive Corporation Method of preheating fuel with an internal heater
US6124579A (en) * 1997-10-06 2000-09-26 Watlow Electric Manufacturing Molded polymer composite heater
US6135360A (en) * 1998-06-01 2000-10-24 Siemens Automotive Corporation Heated tip fuel injector with enhanced heat transfer
US6181874B1 (en) * 1995-08-30 2001-01-30 Isis Innovation Limited Heating element
US6188051B1 (en) 1999-06-01 2001-02-13 Watlow Polymer Technologies Method of manufacturing a sheathed electrical heater assembly
US6233398B1 (en) 1994-12-29 2001-05-15 Watlow Polymer Technologies Heating element suitable for preconditioning print media
US6263158B1 (en) 1999-05-11 2001-07-17 Watlow Polymer Technologies Fibrous supported polymer encapsulated electrical component
WO2002017681A2 (en) * 2000-08-22 2002-02-28 A.T.C.T Advanced Thermal Chips Technologies Ltd. Liquid heating method and apparatus particularly useful for vaporizing a liquid condensate from cooling devices
US6392206B1 (en) 2000-04-07 2002-05-21 Waltow Polymer Technologies Modular heat exchanger
US6392208B1 (en) 1999-08-06 2002-05-21 Watlow Polymer Technologies Electrofusing of thermoplastic heating elements and elements made thereby
US6422481B2 (en) 1998-06-01 2002-07-23 Siemens Automotive Corporation Method of enhancing heat transfer in a heated tip fuel injector
US6433317B1 (en) 2000-04-07 2002-08-13 Watlow Polymer Technologies Molded assembly with heating element captured therein
US6516142B2 (en) 2001-01-08 2003-02-04 Watlow Polymer Technologies Internal heating element for pipes and tubes
US6519835B1 (en) 2000-08-18 2003-02-18 Watlow Polymer Technologies Method of formable thermoplastic laminate heated element assembly
US20030036001A1 (en) * 1995-09-29 2003-02-20 David James Electrical energy devices
DE10163012A1 (en) * 2001-12-20 2003-07-10 Siemens Ag Heating system, for a railway carriage, has heating modules with thermostat control in a honeycomb structure giving the air flow channels and a fan blower to move air through it
US6607804B1 (en) * 1998-03-09 2003-08-19 Thomas Josef Heimbach Gesellschaft Mit Beschrankter Haftung & Co. Molded part made of an electrically conductive ceramic and process for the production of contact zones on such molded parts
US20040065068A1 (en) * 2002-06-17 2004-04-08 Hitachi Metals, Ltd. Ceramic honeycomb filter
US20050085057A1 (en) * 2002-11-12 2005-04-21 Manabu Hashikura Gas heating method and gas heating device
US20050098684A1 (en) * 2003-03-14 2005-05-12 Watlow Polymer Technologies Polymer-encapsulated heating elements for controlling the temperature of an aircraft compartment
US6939522B1 (en) * 1999-11-19 2005-09-06 Ngk Insulators, Ltd. Honeycomb structure
US20060013574A1 (en) * 2003-06-10 2006-01-19 Denso Corporation Electrical heater, heating heat exchanger and vehicle air conditioner
US20060174507A1 (en) * 2005-02-09 2006-08-10 Lin Cheng P Far infrared ray hair dryer
US20070280651A1 (en) * 2006-06-05 2007-12-06 Adda Corp. Fan with a function of far infrared ray emission
US20080067262A1 (en) * 2006-09-14 2008-03-20 S.C. Johnson & Son, Inc. Aerosol Dispenser Assembly Having VOC-Free Propellant and Dispensing Mechanism Therefor
US20080223426A1 (en) * 2007-03-15 2008-09-18 Ibiden Co., Ltd. Thermoelectric converter and method of manufacturing thermoelectric converter
US20080307880A1 (en) * 1999-05-31 2008-12-18 Emitec Gesellschaft Fur Emissionstechnologie Mbh Ceramic Honeycomb Body and Method for Producing the Same
EP2051561A1 (en) * 2007-10-16 2009-04-22 Liebherr-Aerospace Lindenberg GmbH Device with at least one cold conductor
US20090212041A1 (en) * 2006-09-01 2009-08-27 Werner Kahr Heating Element
US20110110652A1 (en) * 2009-11-09 2011-05-12 Technical Analysis & Services International, Inc. (TASI) Active air heater
US20110202019A1 (en) * 2009-12-04 2011-08-18 Mt Industries, Inc. Hand held skin treatment spray system with air heating element
US20110240631A1 (en) * 2007-04-04 2011-10-06 Michael Luppold Electrical heating unit, particularly for cars
US20110309068A1 (en) * 2006-01-30 2011-12-22 Jie-Wei Chen Heating element for a hot air device
US20130186966A1 (en) * 2010-07-21 2013-07-25 Koshiro Taguchi Highly-efficient, hot-water generating, car-mounted heater with internal liquid flow path
US20130287378A1 (en) * 2012-03-22 2013-10-31 Ngk Insulators, Ltd. Heater
US9151295B2 (en) 2008-05-30 2015-10-06 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
USD746971S1 (en) 2012-05-15 2016-01-05 Airius Ip Holdings, Llc Air moving device
US20160025329A1 (en) * 2013-04-17 2016-01-28 Venkata Sundereswar Rao VEMPATI Energy efficient pressure less steam generator
US9335061B2 (en) 2008-05-30 2016-05-10 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
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US20170136138A1 (en) * 2015-11-18 2017-05-18 Xiaoyuan MA Aroma Burner
FR3044545A1 (en) * 2015-12-04 2017-06-09 Welter's Co Ltd HOT AIR AND INFRARED AIR TYPE THERAPEUTIC APPARATUS WITH MULTIPLE FUNCTIONS
US9702576B2 (en) 2013-12-19 2017-07-11 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
USD805176S1 (en) 2016-05-06 2017-12-12 Airius Ip Holdings, Llc Air moving device
USD820967S1 (en) 2016-05-06 2018-06-19 Airius Ip Holdings Llc Air moving device
US10024531B2 (en) 2013-12-19 2018-07-17 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
CN108365086A (en) * 2018-02-08 2018-08-03 重庆医科大学 A kind of piezoelectric ceramics electrode and preparation method thereof
US10221861B2 (en) 2014-06-06 2019-03-05 Airius Ip Holdings Llc Columnar air moving devices, systems and methods
US10487852B2 (en) 2016-06-24 2019-11-26 Airius Ip Holdings, Llc Air moving device
USD885550S1 (en) 2017-07-31 2020-05-26 Airius Ip Holdings, Llc Air moving device
USD886275S1 (en) 2017-01-26 2020-06-02 Airius Ip Holdings, Llc Air moving device
USD887541S1 (en) 2019-03-21 2020-06-16 Airius Ip Holdings, Llc Air moving device
EP3773061A4 (en) * 2019-06-19 2021-02-17 Farouk Systems, Inc. Lava rock containing hair styling devices
CN112567885A (en) * 2018-08-13 2021-03-26 日本碍子株式会社 Heater member for heating vehicle cabin, method of using the same, and heater for heating vehicle cabin
CN114763308A (en) * 2021-01-15 2022-07-19 日本碍子株式会社 Ceramic body and manufacturing method thereof, heater member, heater unit, heater system, and purge system
US11528980B2 (en) 2017-12-21 2022-12-20 Farouk Systems, Inc. Lava rock containing hair styling devices
US11598539B2 (en) 2019-04-17 2023-03-07 Airius Ip Holdings, Llc Air moving device with bypass intake

Families Citing this family (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5080649A (en) * 1973-11-19 1975-06-30
JPS50106149U (en) * 1974-02-06 1975-09-01
JPS5150428U (en) * 1974-10-15 1976-04-16
JPS5176839U (en) * 1974-12-13 1976-06-17
JPS5628704Y2 (en) * 1975-01-31 1981-07-08
JPS5192441A (en) * 1975-02-12 1976-08-13
JPS5818815Y2 (en) * 1975-03-14 1983-04-16 株式会社東芝 coffee liquid extraction equipment
JPS5825967Y2 (en) * 1975-03-14 1983-06-04 株式会社東芝 coffee liquid extraction equipment
JPS51130938A (en) * 1975-05-10 1976-11-13 Ngk Insulators Ltd Heat generating element
JPS51159064U (en) * 1975-06-12 1976-12-17
JPS528996U (en) * 1975-07-07 1977-01-21
JPS5216054U (en) * 1975-07-23 1977-02-04
JPS5229638A (en) * 1975-09-02 1977-03-05 Mitsubishi Electric Corp Heat releasing unit
JPS5241043U (en) * 1975-09-17 1977-03-23
JPS5553100Y2 (en) * 1975-11-07 1980-12-09
JPS5273363A (en) * 1975-12-17 1977-06-20 Hitachi Ltd Thermistor with positive characteristics and method of making same
JPS5314430A (en) * 1976-07-07 1978-02-09 Hitachi Heating Appliance Co Ltd Circuit for heating unit
JPS5316134A (en) * 1976-07-29 1978-02-14 Nippon Denso Co Ltd Carburetor having heater for use in internal combustion engine
DE2760239C2 (en) * 1976-09-09 1990-12-06 Texas Instruments Inc., Dallas, Tex., Us
JPS5475638A (en) * 1977-11-28 1979-06-16 Ngk Spark Plug Co Ltd Suction heater for internal combustion engine
DE2821207C2 (en) * 1978-05-13 1983-07-07 Danfoss A/S, 6430 Nordborg Atomizing burners for oil firing systems
US4310747A (en) * 1978-07-26 1982-01-12 The Fluorocarbon Company Method and apparatus utilizing a porous vitreous carbon body particularly for fluid heating
US4220846A (en) * 1978-07-26 1980-09-02 The Fluorocarbon Company Method and apparatus utilizing a porous vitreous carbon body particularly for fluid heating
US4334350A (en) * 1978-07-26 1982-06-15 Chemotronics International, Inc. Shareholders Method utilizing a porous vitreous carbon body particularly for fluid heating
DE2840242C2 (en) * 1978-09-15 1984-08-23 Siemens AG, 1000 Berlin und 8000 München Heating device for preheating heating oil
JPS55116317A (en) * 1979-03-01 1980-09-06 Orient Kk Hot wind hand drier
DE2946842C2 (en) * 1979-11-20 1983-04-14 Siemens AG, 1000 Berlin und 8000 München A heating element made of PTC thermistor material consisting of a honeycomb body
JPS58101491U (en) * 1981-12-28 1983-07-09 松下電器産業株式会社 Positive temperature coefficient thermistor heating element
DE3204207C2 (en) * 1982-02-08 1985-05-23 Siemens AG, 1000 Berlin und 8000 München Electrical resistance with a ceramic PTC body and method for its manufacture
CA1231748A (en) * 1985-02-11 1988-01-19 Kosta Pelonis Electric heater employing semiconductor heating elements
JP2898364B2 (en) * 1990-07-06 1999-05-31 日本碍子株式会社 Electrode integrated honeycomb heater and method for manufacturing the same
DE4216008C5 (en) * 1992-05-12 2006-06-01 Suntec Industries France, S.A. Preheater for the nozzle of an oil burner
DE10118599B4 (en) * 2001-04-12 2006-07-06 Webasto Ag Electric heater
DE10201262B4 (en) * 2002-01-15 2006-09-07 Webasto Ag resistance
GB2454022A (en) * 2007-10-27 2009-04-29 Uav Engines Ltd Fuel heating apparatus to aid cold starts in low ambient temperatures
AU2011318436B2 (en) 2010-09-28 2015-07-02 Baxter Healthcare Sa Optimization of nucleation and crystallization for lyophilization using gap freezing
US8966782B2 (en) 2010-09-28 2015-03-03 Baxter International Inc. Optimization of nucleation and crystallization for lyophilization using gap freezing
CN107218721A (en) * 2017-06-01 2017-09-29 华南理工大学 A kind of high-temperature heat flux transmitter

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US927173A (en) * 1908-05-20 1909-07-06 Fried Krupp Germaniawerft Ag Electric heater.
US1334809A (en) * 1918-11-13 1920-03-23 Simon Jules Electric resistance-furnace
US3163841A (en) * 1962-01-02 1964-12-29 Corning Glass Works Electric resistance heater
US3244860A (en) * 1962-04-26 1966-04-05 Parsons C A & Co Ltd Heaters for gases
US3265865A (en) * 1963-10-09 1966-08-09 Armstrong Cork Co Electrical duct heater
US3582613A (en) * 1968-10-11 1971-06-01 Othmar W Pies Fluid-heating device
US3619560A (en) * 1969-12-05 1971-11-09 Texas Instruments Inc Self-regulating thermal apparatus and method
US3691346A (en) * 1969-07-03 1972-09-12 Danfoss As Electrically heated catalytic air purifier

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3279931A (en) * 1963-02-13 1966-10-18 Corning Glass Works Glass-ceramic body and method of making it
JPS419800Y1 (en) * 1964-08-20 1966-05-11
US3413442A (en) * 1965-07-15 1968-11-26 Texas Instruments Inc Self-regulating thermal apparatus
JPS4528568Y1 (en) * 1965-12-23 1970-11-04
JPS4318230Y1 (en) * 1965-12-23 1968-07-27
US3400250A (en) * 1966-01-03 1968-09-03 Texas Instruments Inc Heating apparatus
JPS5239561Y2 (en) * 1971-10-18 1977-09-07
JPS553371Y2 (en) * 1975-09-12 1980-01-26

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US927173A (en) * 1908-05-20 1909-07-06 Fried Krupp Germaniawerft Ag Electric heater.
US1334809A (en) * 1918-11-13 1920-03-23 Simon Jules Electric resistance-furnace
US3163841A (en) * 1962-01-02 1964-12-29 Corning Glass Works Electric resistance heater
US3244860A (en) * 1962-04-26 1966-04-05 Parsons C A & Co Ltd Heaters for gases
US3265865A (en) * 1963-10-09 1966-08-09 Armstrong Cork Co Electrical duct heater
US3582613A (en) * 1968-10-11 1971-06-01 Othmar W Pies Fluid-heating device
US3691346A (en) * 1969-07-03 1972-09-12 Danfoss As Electrically heated catalytic air purifier
US3619560A (en) * 1969-12-05 1971-11-09 Texas Instruments Inc Self-regulating thermal apparatus and method

Cited By (138)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4123851A (en) * 1975-07-18 1978-11-07 Hitachi, Ltd. Clothes drier
US4032752A (en) * 1975-09-03 1977-06-28 Ngk Insulators, Ltd. Heating elements comprising a ptc ceramic article of a honeycomb structure composed of barium titanate
US4316077A (en) * 1975-12-31 1982-02-16 Texas Instruments Incorporated Elastic hair dryer having selectively variable air output temperature
US4177778A (en) * 1976-07-29 1979-12-11 Nippondenso Co., Ltd. Carburetors with heating device
US4180901A (en) * 1976-09-09 1980-01-01 Texas Instruments Incorporated Compact PTC resistor
US4198669A (en) * 1976-09-09 1980-04-15 Texas Instruments Incorporated Compact PTC resistor
US4141327A (en) * 1976-09-09 1979-02-27 Texas Instruments Incorporated Early fuel evaporation carburetion system
US4107515A (en) * 1976-09-09 1978-08-15 Texas Instruments Incorporated Compact PTC resistor
US4108125A (en) * 1976-09-10 1978-08-22 Texas Instruments Incorporated High efficiency early fuel evaporation carburetion system
US4212275A (en) * 1976-11-05 1980-07-15 Nissan Motor Company, Limited Carburetor
DE2752752A1 (en) * 1976-11-26 1978-06-01 Ngk Insulators Ltd PROCESS FOR MANUFACTURING BODIES WITH A HONEYCOMB STRUCTURE FROM CERAMIC MATERIALS OF THE BARIUM TITANATE GROUP WITH POSITIVE TEMPERATURE RESISTANCE COEFFICIENTS
US4293514A (en) * 1976-11-26 1981-10-06 Ngk Insulators, Ltd. Method of producing honeycomb structural bodies consisting of barium titanate series ceramics having a positive temperature coefficient of electric resistance
US4245146A (en) * 1977-03-07 1981-01-13 Tdk Electronics Company Limited Heating element made of PTC ceramic material
DE2904276A1 (en) * 1978-02-06 1979-08-16 Ngk Insulators Ltd BARIUM TITANATE HOMOLOGOUS CERAMIC MATERIALS
DE2905905A1 (en) * 1978-02-22 1979-08-23 Tdk Electronics Co Ltd COMB-SHAPED HEATING ELEMENT
US4232214A (en) * 1978-02-22 1980-11-04 Tdk Electronics Company Limited PTC Honeycomb heating element with multiple electrode layers
US4279234A (en) * 1979-01-12 1981-07-21 Texas Instruments Incorporated Early fuel evaporation of carburetion system
US4447706A (en) * 1979-03-27 1984-05-08 Danfoss A/S Nozzle assembly with integrated PTC heater for prewarming fuel oil
US4369029A (en) * 1979-03-29 1983-01-18 Kernforschungsanlage Julich Gmbh Ceramic recuperator and method for the heating of combustion air
US4264888A (en) * 1979-05-04 1981-04-28 Texas Instruments Incorporated Multipassage resistor and method of making
US4654510A (en) * 1979-10-11 1987-03-31 Tdk Electronics Co., Ltd. PTC heating apparatus
DE2946799A1 (en) * 1979-11-20 1981-05-21 Siemens AG, 1000 Berlin und 8000 München Heating element with PTC honeycomb body - made from small extruded ceramic pipes sintered together and having current supply points on opposite faces
US4401879A (en) * 1981-02-20 1983-08-30 Texas Instruments Incorporated Self-regulating electrical resistance heater and fuel supply system using the heater
US4629864A (en) * 1983-12-23 1986-12-16 Black & Decker, Inc. Hot air gun
US4598686A (en) * 1985-03-28 1986-07-08 Casco Products Inc. Fuel vapor recovery system for automotive vehicles
US4721846A (en) * 1986-07-02 1988-01-26 Casco Products Corporation Canister heater with PTC wafer
US4717401A (en) * 1986-09-24 1988-01-05 Casco Products Corporation Fuel vapor recovery system
US4736718A (en) * 1987-03-19 1988-04-12 Linder Henry C Combustion control system for internal combustion engines
US4855571A (en) * 1988-01-29 1989-08-08 Industrial Technology Research Institute Positive temperature coefficient ceramic heating element for heating a fluid
US4886956A (en) * 1988-10-26 1989-12-12 Gte Products Corporation Method of electroding PTC heaters
US5266278A (en) * 1990-07-06 1993-11-30 Ngk Insulators, Ltd. Honeycomb heater having integrally formed electrodes and/or integrally sintered electrodes and method of manufacturing such honeycomb heater
US5206476A (en) * 1991-09-30 1993-04-27 General Motors Corporation Supplementary automobile duct heater
US5461695A (en) * 1992-08-05 1995-10-24 Paul Ritzau Pari-Werk Gmbh Nebulizing assembly with heating equipment
US5634457A (en) * 1992-09-30 1997-06-03 Nippon Chemical Plant Consultant Co., Ltd. Gas heating apparatus
US5513296A (en) * 1994-06-08 1996-04-30 Holmes Products Corp. Air heater with angled PTC heaters producing diverging heated airflow
USRE37642E1 (en) * 1994-06-08 2002-04-09 The Holmes Group, Inc. Air heater with angled PTC heaters producing diverging heated airflow
US5835679A (en) * 1994-12-29 1998-11-10 Energy Converters, Inc. Polymeric immersion heating element with skeletal support and optional heat transfer fins
US5930459A (en) * 1994-12-29 1999-07-27 Energy Converters, Inc. Immersion heating element with highly thermally conductive polymeric coating
US5586214A (en) * 1994-12-29 1996-12-17 Energy Convertors, Inc. Immersion heating element with electric resistance heating material and polymeric layer disposed thereon
US6432344B1 (en) 1994-12-29 2002-08-13 Watlow Polymer Technology Method of making an improved polymeric immersion heating element with skeletal support and optional heat transfer fins
US6233398B1 (en) 1994-12-29 2001-05-15 Watlow Polymer Technologies Heating element suitable for preconditioning print media
US6181874B1 (en) * 1995-08-30 2001-01-30 Isis Innovation Limited Heating element
US20030036001A1 (en) * 1995-09-29 2003-02-20 David James Electrical energy devices
US6109543A (en) * 1996-03-29 2000-08-29 Siemens Automotive Corporation Method of preheating fuel with an internal heater
US5758826A (en) * 1996-03-29 1998-06-02 Siemens Automotive Corporation Fuel injector with internal heater
US6102303A (en) * 1996-03-29 2000-08-15 Siemens Automotive Corporation Fuel injector with internal heater
US6124579A (en) * 1997-10-06 2000-09-26 Watlow Electric Manufacturing Molded polymer composite heater
EP0919154A3 (en) * 1997-11-29 2001-01-24 Samsung Electronics Co., Ltd. Hair dryer
EP0919154A2 (en) * 1997-11-29 1999-06-02 Samsung Electronics Co., Ltd. Hair dryer
US6607804B1 (en) * 1998-03-09 2003-08-19 Thomas Josef Heimbach Gesellschaft Mit Beschrankter Haftung & Co. Molded part made of an electrically conductive ceramic and process for the production of contact zones on such molded parts
US6135360A (en) * 1998-06-01 2000-10-24 Siemens Automotive Corporation Heated tip fuel injector with enhanced heat transfer
US6422481B2 (en) 1998-06-01 2002-07-23 Siemens Automotive Corporation Method of enhancing heat transfer in a heated tip fuel injector
US6263158B1 (en) 1999-05-11 2001-07-17 Watlow Polymer Technologies Fibrous supported polymer encapsulated electrical component
US6434328B2 (en) 1999-05-11 2002-08-13 Watlow Polymer Technology Fibrous supported polymer encapsulated electrical component
US20080307880A1 (en) * 1999-05-31 2008-12-18 Emitec Gesellschaft Fur Emissionstechnologie Mbh Ceramic Honeycomb Body and Method for Producing the Same
US8529842B2 (en) * 1999-05-31 2013-09-10 Emitec Gesellschaft Fuer Emissionstechnologie Mbh Ceramic honeycomb body and method for producing the same
US6188051B1 (en) 1999-06-01 2001-02-13 Watlow Polymer Technologies Method of manufacturing a sheathed electrical heater assembly
US6392208B1 (en) 1999-08-06 2002-05-21 Watlow Polymer Technologies Electrofusing of thermoplastic heating elements and elements made thereby
US6939522B1 (en) * 1999-11-19 2005-09-06 Ngk Insulators, Ltd. Honeycomb structure
US6748646B2 (en) * 2000-04-07 2004-06-15 Watlow Polymer Technologies Method of manufacturing a molded heating element assembly
US6433317B1 (en) 2000-04-07 2002-08-13 Watlow Polymer Technologies Molded assembly with heating element captured therein
US6392206B1 (en) 2000-04-07 2002-05-21 Waltow Polymer Technologies Modular heat exchanger
US6519835B1 (en) 2000-08-18 2003-02-18 Watlow Polymer Technologies Method of formable thermoplastic laminate heated element assembly
US6541744B2 (en) 2000-08-18 2003-04-01 Watlow Polymer Technologies Packaging having self-contained heater
US6965732B2 (en) 2000-08-22 2005-11-15 A.T.C.T. Advanced Thermal Chips Technologies Ltd. Liquid heating method and apparatus particularly useful for vaporizing a liquid condensate from cooling devices
WO2002017681A3 (en) * 2000-08-22 2002-07-18 A T C T Advanced Thermal Chips Liquid heating method and apparatus particularly useful for vaporizing a liquid condensate from cooling devices
WO2002017681A2 (en) * 2000-08-22 2002-02-28 A.T.C.T Advanced Thermal Chips Technologies Ltd. Liquid heating method and apparatus particularly useful for vaporizing a liquid condensate from cooling devices
US6539171B2 (en) 2001-01-08 2003-03-25 Watlow Polymer Technologies Flexible spirally shaped heating element
US6744978B2 (en) 2001-01-08 2004-06-01 Watlow Polymer Technologies Small diameter low watt density immersion heating element
US6516142B2 (en) 2001-01-08 2003-02-04 Watlow Polymer Technologies Internal heating element for pipes and tubes
DE10163012A1 (en) * 2001-12-20 2003-07-10 Siemens Ag Heating system, for a railway carriage, has heating modules with thermostat control in a honeycomb structure giving the air flow channels and a fan blower to move air through it
DE10163012B4 (en) * 2001-12-20 2006-01-26 Siemens Ag Heating, in particular for a rail vehicle
US20040065068A1 (en) * 2002-06-17 2004-04-08 Hitachi Metals, Ltd. Ceramic honeycomb filter
US7090714B2 (en) * 2002-06-17 2006-08-15 Hitachi Metals, Ltd. Ceramic honeycomb filter
US20050085057A1 (en) * 2002-11-12 2005-04-21 Manabu Hashikura Gas heating method and gas heating device
US20050098684A1 (en) * 2003-03-14 2005-05-12 Watlow Polymer Technologies Polymer-encapsulated heating elements for controlling the temperature of an aircraft compartment
US20060013574A1 (en) * 2003-06-10 2006-01-19 Denso Corporation Electrical heater, heating heat exchanger and vehicle air conditioner
US10487840B2 (en) 2004-03-15 2019-11-26 Airius Ip Holdings, Llc Temperature destratification systems
US11053948B2 (en) 2004-03-15 2021-07-06 Airius Ip Holdings, Llc Temperature destratification systems
US9714663B1 (en) 2004-03-15 2017-07-25 Airius Ip Holdings, Llc Temperature destratification systems
US11703062B2 (en) 2004-03-15 2023-07-18 Airius Ip Holdings, Llc Temperature destratification systems
US11365743B2 (en) 2004-03-15 2022-06-21 Airius Ip Holdings, Llc Temperature destratification systems
US9631627B2 (en) 2004-03-15 2017-04-25 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
US20060174507A1 (en) * 2005-02-09 2006-08-10 Lin Cheng P Far infrared ray hair dryer
US20110309068A1 (en) * 2006-01-30 2011-12-22 Jie-Wei Chen Heating element for a hot air device
US20070280651A1 (en) * 2006-06-05 2007-12-06 Adda Corp. Fan with a function of far infrared ray emission
US20090212041A1 (en) * 2006-09-01 2009-08-27 Werner Kahr Heating Element
US8373100B2 (en) 2006-09-01 2013-02-12 Epcos Ag Heating element
US20080067262A1 (en) * 2006-09-14 2008-03-20 S.C. Johnson & Son, Inc. Aerosol Dispenser Assembly Having VOC-Free Propellant and Dispensing Mechanism Therefor
US20080223426A1 (en) * 2007-03-15 2008-09-18 Ibiden Co., Ltd. Thermoelectric converter and method of manufacturing thermoelectric converter
US20110240631A1 (en) * 2007-04-04 2011-10-06 Michael Luppold Electrical heating unit, particularly for cars
US8212647B2 (en) 2007-10-16 2012-07-03 Liebherr-Aerospace Lindenberg Gmbh Device having at least one PTC resistor
RU2488983C2 (en) * 2007-10-16 2013-07-27 Либхерр-Аэроспейс Линденберг Гмбх Device with ptk resistor
US20090121824A1 (en) * 2007-10-16 2009-05-14 Franz Feuerstein Device having at least one PTC resistor
EP2051561A1 (en) * 2007-10-16 2009-04-22 Liebherr-Aerospace Lindenberg GmbH Device with at least one cold conductor
US9151295B2 (en) 2008-05-30 2015-10-06 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
US9970457B2 (en) 2008-05-30 2018-05-15 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
US9335061B2 (en) 2008-05-30 2016-05-10 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
US9459020B2 (en) 2008-05-30 2016-10-04 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
US20110110652A1 (en) * 2009-11-09 2011-05-12 Technical Analysis & Services International, Inc. (TASI) Active air heater
US20110202019A1 (en) * 2009-12-04 2011-08-18 Mt Industries, Inc. Hand held skin treatment spray system with air heating element
US20130186966A1 (en) * 2010-07-21 2013-07-25 Koshiro Taguchi Highly-efficient, hot-water generating, car-mounted heater with internal liquid flow path
US10184489B2 (en) 2011-06-15 2019-01-22 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
US9383119B2 (en) * 2012-03-22 2016-07-05 Ngk Insulators, Ltd. Heater
US20130287378A1 (en) * 2012-03-22 2013-10-31 Ngk Insulators, Ltd. Heater
USD783795S1 (en) 2012-05-15 2017-04-11 Airius Ip Holdings, Llc Air moving device
USD746971S1 (en) 2012-05-15 2016-01-05 Airius Ip Holdings, Llc Air moving device
USD926963S1 (en) 2012-05-15 2021-08-03 Airius Ip Holdings, Llc Air moving device
US9664378B2 (en) * 2013-04-17 2017-05-30 Venkata Sundereswar Rao VEMPATI Energy efficient pressure less steam generator
US20160025329A1 (en) * 2013-04-17 2016-01-28 Venkata Sundereswar Rao VEMPATI Energy efficient pressure less steam generator
US9702576B2 (en) 2013-12-19 2017-07-11 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
US11092330B2 (en) 2013-12-19 2021-08-17 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
US10024531B2 (en) 2013-12-19 2018-07-17 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
US10641506B2 (en) 2013-12-19 2020-05-05 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
US10655841B2 (en) 2013-12-19 2020-05-19 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
US11221153B2 (en) 2013-12-19 2022-01-11 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
US10221861B2 (en) 2014-06-06 2019-03-05 Airius Ip Holdings Llc Columnar air moving devices, systems and methods
US11713773B2 (en) 2014-06-06 2023-08-01 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
US11236766B2 (en) 2014-06-06 2022-02-01 Airius Ip Holdings Llc Columnar air moving devices, systems and methods
US10724542B2 (en) 2014-06-06 2020-07-28 Airius Ip Holdings, Llc Columnar air moving devices, systems and methods
US20170136138A1 (en) * 2015-11-18 2017-05-18 Xiaoyuan MA Aroma Burner
FR3044545A1 (en) * 2015-12-04 2017-06-09 Welter's Co Ltd HOT AIR AND INFRARED AIR TYPE THERAPEUTIC APPARATUS WITH MULTIPLE FUNCTIONS
USD820967S1 (en) 2016-05-06 2018-06-19 Airius Ip Holdings Llc Air moving device
USD805176S1 (en) 2016-05-06 2017-12-12 Airius Ip Holdings, Llc Air moving device
US11421710B2 (en) 2016-06-24 2022-08-23 Airius Ip Holdings, Llc Air moving device
US10487852B2 (en) 2016-06-24 2019-11-26 Airius Ip Holdings, Llc Air moving device
US11105341B2 (en) 2016-06-24 2021-08-31 Airius Ip Holdings, Llc Air moving device
USD886275S1 (en) 2017-01-26 2020-06-02 Airius Ip Holdings, Llc Air moving device
USD885550S1 (en) 2017-07-31 2020-05-26 Airius Ip Holdings, Llc Air moving device
US11528980B2 (en) 2017-12-21 2022-12-20 Farouk Systems, Inc. Lava rock containing hair styling devices
CN108365086A (en) * 2018-02-08 2018-08-03 重庆医科大学 A kind of piezoelectric ceramics electrode and preparation method thereof
CN112567885B (en) * 2018-08-13 2023-02-28 日本碍子株式会社 Heater member for heating vehicle cabin, method of using the same, and heater for heating vehicle cabin
CN112567885A (en) * 2018-08-13 2021-03-26 日本碍子株式会社 Heater member for heating vehicle cabin, method of using the same, and heater for heating vehicle cabin
USD887541S1 (en) 2019-03-21 2020-06-16 Airius Ip Holdings, Llc Air moving device
US11598539B2 (en) 2019-04-17 2023-03-07 Airius Ip Holdings, Llc Air moving device with bypass intake
US11781761B1 (en) 2019-04-17 2023-10-10 Airius Ip Holdings, Llc Air moving device with bypass intake
EP3773061A4 (en) * 2019-06-19 2021-02-17 Farouk Systems, Inc. Lava rock containing hair styling devices
CN114763308A (en) * 2021-01-15 2022-07-19 日本碍子株式会社 Ceramic body and manufacturing method thereof, heater member, heater unit, heater system, and purge system

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NL7403188A (en) 1974-09-11
NL161030C (en) 1979-12-17
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DE2410999B2 (en) 1976-07-08
JPS5148815B2 (en) 1976-12-23
JPS49114130A (en) 1974-10-31

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