US2730299A - Coiled tube continuous centrifuge - Google Patents

Description

COILED TUBE CONTINUOUS CENTRIFUGEI Filed Nov. 27, 1955 3 Sheets-Sheet l INVENTOR; WILLIAM H. KELSEY,

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Jan. 10, 1956 w. H. KELSEY COILED TUBE CONTINUOUS CENTRIFUGE 3 Sheets-Sheet 2 Filed Nov. 27, 1953 F/G Z.

IN V EN TOR.

WILLIAM H. KELSEY,

*1 mm Krrawvzra.

Jan. 10, 1956 w. H. KELSEY 2,730,299

COILED TUBE CONTINUOUS CENTRIFUGE Filed Nov. 27, 1955 3 Sheets-Sheet 3 INVENTOR, WILLIAM H. KELSEY,

United States Patent 055cc 2,730,299 Patented Jan. 10, 1956 2,730,299 CUILED TUBE CQNTENUUUS CENTRIFUGE William H. Keisey, fltockton, Utah, assignor to Combined Metals Reduction Company, Salt Lake City, Utah, a corporation of Utah Appiication November 27, 1953, Serial No. 394,561 9 Claims. (Cl. 2333) This invention relates to centrifugal machines for operating upon metallurgical and other industrial pulps and slurries in the processing of same for a variety of purposes, and is concerned particularly with a machine of this type adapted for handling a continuous flow of material.

The centrifugal machine of the present invention is closely related to that illustrated and described in my copending application for U. S. Patent, Serial No. 292,450, filed June 9, 1952, and entitled Continuous Centrifuge. It differs, however, in several important respects, principally in the formation of the centrifuge chamber.

The machine of my aforementioned application for patent is characterized by the provision of a convoluted, continuous, flexible rib extending longitudinally of and open to the centrifuge chamber, so as to form a deformable part of the latter, and by the provision, further, of mechanism for progressively squeezing such flexible rib during the rotation of the centrifuge chamber, in order to induce what I choose to call a peristaltic action within and along the rib, for transporting material through and out of the chamber.

The machine of the present invention likewise embodies a convoluted, continuous, flexible rib, and makes use of the so-called peristaltic action for the transportation of material being processed, but employs a coiled, flexible tube to provide the centrifuge chamber, thereby obtaining the convoluted flexible rib as a necessary'and incidental feature of the centrifuge chamber itself.

While it is preferred that the tube be wholly formed of a flexible resilient material, such as rubber suitably reinforced for strength and wear as may be required in any given instance of use, so that the body of the tube is integral and flexible throughout its, entire circumferential extent in the manner of a hose, other constructions are possible, so long as that longitudinally extending portion of the tube which faces outwardly from the rotative axis is flexible.

In the preferred instance, where the tube is in the nature of a hose, a backing of rigid material is ordinarily provided, though it is not always necessary, depending upon the structural characteristics of the tube and the use to which the machine is to be put. In both instances, however, rotatable supporting structure is provided for carrying the tube, and, especially in the first instance, it is preferred that such supporting structure include a rigid backing for the tube.

Regardless of the manner of construction, however, the coiled tube provides an elongate centrifuge chamber of coiled configuration, and has at least the outer longitudinal portion thereof flexible and preferably also resilient in character.

A principal object of the present invention is to provide the functional advantages of my previously developed continuous centrifuge in a machine of lower cost and having the advantage of considerably lower maintenance costs.

Other objects and purposes of the invention are to provide for greater stability of the centrifuge chamber in operation, for greater facility of charging and discharging the centrifuge chamber, for enhancing the rapidity with which any given centrifuging operation is accomplished, for enhancing the effectiveness of the centrifuging operation, for obtaining a more positive peristaltic action, for enabling relatively quick and easy replacement of parts subject to wear, and for facilitating the fabrication and supply of flexible components of the centrifuge chamber.

Further objects and features of the invention will become apparent from the following detailed description of the preferred specific embodiment illustrated in the accompanying drawings.

In the drawings:

Fig. 1 represents a View partly in elevation and partly in central vertical section taken approximately along the line 11 of Fig. 3;

Fig. 2, a horizontal section taken on the line 22 of Fig. 1, portions being broken away and certain structure in the background being eliminated for convenience of illustration;

Fig. 3, a horizontal section taken approximately along the line 3-3 of Fig. 1;

Fig. 4, a horizontal section taken on the line 44 of Fig. 1; and

Fig. 5, a detail in fragmentary vertical section taken on the line 5-5 of Fig. 4.

Referring now to the drawings:

The preferred embodiment illustrated has the rotative axis of its centrifuge bowl extending vertically, though it should be realized that it may be disposed horizontally, or at any desired angle relative to the vertical or the horizontal, as may be found suitable for particular instances of use;

Since the characteristic feature of the invention resides in the fact that the centrifuge bowl proper is a coiled tube through which the material being operated upon flows continuously, provision is made for supporting the tube in its coiled condition and for maintaining it in such coiled condition during the rotation thereof.

In the form illustrated, the tube it constituting the centrifuge bowl proper, is closely coiled in helical formation about a correspondingly helical, receiving channel 11:: formed in the outer circumferential surface of a rigid, supporting and backing cylinder 11, which is rigidly affixed to an elongate hollow shaft rotatably mounted in a stationary structural framework.

The centrifuge tube in is of hose-like character, being made up of flexible resilient material, such as rubber, suitably reinforced to impart strength and durability without unduly altering its flexible character. In this connection, it should be noted that, while tubes or hosing having desirable characteristics of flexibility and resiliency are readily obtainable on the open market in sizes conforming to most requirements, the continual transverse flexure to which the centrifuge tube of this machine is subjected during operation makes it highly desirable that the tubes or hosing be structurally reinforced by cord, fabric, or the like in the manner of an automobile tire, so as to be durable and withstand hard usage. It is preferred that the tubing be vulcanized or otherwise firmly secured to the walls of the receiving channel 114:.

The size of the tubing in cross-section is not critical and may conform to processing requirements in any given instance, considering the material to be processed and the desired through-put capacity of the machine per unit time.

The supporting cylinder 11 may be fabricated and may be mounted for rotation in various ways. It is preferred, however, that it be so constructed and associated with other parts of the machine as to be readiiy and. conveniently removable, together with the centrifuge tube coiled therearound, for replacement of such tube when necessary, and so as to be just as readily and conveniently replaceable, following repairs to or replacement of such centrifuge tube.

In the presently preferred construction illustrated, the supporting cylinder 11 is provided with reinforcing spiders 12 at its respectively opposite, open ends, and with a tubular, axially disposed member 13 extending longitudinally thereof and rigidly secured to the respective spiders 12, centrally thereof, as by welding. The opposite ends of the tubular member 13 are open, but an intermediate portion of such member is closed off by respective partition plates 14 welded across the tubes interior, thereby leaving opposite end portions 13a and 1311, respectively, of such tubular member open as flow passages.

As so constructed, this centrifuge bowl portion of the machine is adapted to be easily slid into and out of position relative to mutually spaced, rotatably mounted, hollow shaft structures, and, forthe purpose of rigidly securing such centrifuge bowl structure to the shaft structures by which it is received, the respective end spiders 12 of the supporting cylinder 11 extend outwardly of the latter to form securement flanges 12a at opposite ends of the centrifuge bowl structure.

The mutually spaced, rotatable, hollow shaft structures adapted to receive and secure the centrifuge bowl structure are here shown as made up of mutually aligned, tubular, shaft sections 15 and 16, respectively, rotatably mounted in respective antifriction bearings 17 and 18, which are, in turn, supported by horizontally extending frame members 19 and 20, respectively, Figs. 1 and 4, of a structural framework comprising a triangularly configurated base frame 21, advantageously fabricated from structural steel I-beams, as shown, and mutually spaced uprights or columns 22 rising from the corners of such base frame.

The mutually opposed ends of shaft sections 15 and 16 are provided with slideway members in the form of outwardly extending, circumferential plates 23 and 24, respectively, which make for convenient positioning of the centrifuge bowl structure between the rotatable hollow shaft structures, and for convenient rigid securement of such received centrifuge bowl structure in position by suitable fastening means, such as bolts 25 passing through the flanges 12a.

As so assembled, the opposed shaft sections 15 and 16 and the tubular member 13 of the centrifuge bowl structure, together, make up an elongate, rigid, rotatable shaft, to which the centrifuge tube 19 is rigidly secured by means of its supporting and backing cylinder 11.

The composite shaft and associated centrifuge bowl structure may be rotated in any suitable fashion, for example, by means of an electric motor (not shown) connected with a drive sheave 26 by V-belts, in conventional manner.

Feed of material to this centrifuge machine and discharge therefrom of lighter components, usually liquid, separated from such material during its passage along the elongate and coiled centrifuge chamber 27 provided by the tube 10, are advantageously and preferably accomplished through the respective hollow and open opposite end portions of the composite shaft.

Thus, the material to be processed is introduced in any suitable fashion into the open upper end 28 of the shaft section 15, passing down through such section into the flow passage 13a of the shaft member 13.

In order to establish a fluid-tight, flow connection between the flow passage 13a and the adjacent end 10a of the centrifuge tube, a nipple 29 extends outwardly from the shaft member 13, and has such tube end 10a snugly fitted thereover, a clamping collar 30 being applied to render the connection secure.

The supporting cylinder 11 is formed with. an internally flanged opening, 31 for accommodating the extension of tube 10 to the feed connection afore-described.

In much the same way, the opposite end 1% of the centrifuge tube 10 is connected in fluid-tight, materialfiow relationship with the flow passage 13b in the opposite end portion of shaft member 13, and discharge therefrom passes into the hollow interior of shaft section 15 and out the open lower end thereof. Control of the discharge is effected, in this instance, by an aperturcd plug 32 threaded into the free end of a sleeve coupling 33, which is secured, as by welding, to the open lower end of the shaft section 16. By removing such plug 32 and replacing the same with another having a discharge orifice 32a of different size, the rate of discharge flow is effectively established to accord with any given operating run of the machine.

For the purpose of conveniently and continuously discharging heavier or solid components of the feed material as segregated by centrifugal action against those interior walls 34 of the tube 16 which are remotely disposed relative to the supporting cylinder 11, such tube is partitioned longitudinally along a portion of its discharge end by means of an internal, dividing wall 35, such wall providing a flow passage 36 terminating in a closed pocket 36:: adjacent the discharge end of the tube. A depending, flexible nipple 37 leads from such closed pocket, and is provided with an encircling, annular, squeeze valve 38, which may be adjusted from time to time to regulate the size of the discharge opening as desired. Thus, heavier or solid portions of the material fed to the machine, as separated from lighter or liquid portions of such material by the centrifugal action of the machine, and as transported along wall 34 of the centrifuge tube 10 by the peristaltic or wave action about to be described, are effectively discharged separately from such lighter portions.

A stationary trough 39, of annular formation and equipped with one or more discharge chutes 40, provides an excellent way of receiving the discharge from nipple 37 as the centrifugal bowl structure executes its rotary motion. The discharge chutes may empty into any suitable container (not shown).

As in my aforementioned, copending application for Patent Serial No. 292,450, means are provided for establishing transportative wave action along the length of the outwardly projecting, flexible rib provided by the centrifuge tube, thereby insuring positive and continuous travel of the heavier components of the feed material through and out of the centrifuge chamber.

In this instance, as in that of my said previous application for patent, a series of rollers are provided at intervals about the circumferential periphery of the coiled centrifuge tube 10 and extending longitudinally with the rotative axis of such tube. As shown, rollers 41 are rotatably mounted in respective sets of eccentric bearings 42 and 43, which bearings are supported by bracket members 44 and 45, respectively, secured to and supported by members 46 and 47, respectively, of respective structural frames attached, as by welding, to the uprights 22.

Each set of bearings is adapted for manual adjustment about the rotative axis of the particular roller concerned, as by means of a handle 48, Figs. 1 and 3, for moving the roller toward or away from the centrifuge tube, substantially radially thereof. 'For maintaining the position of the roller in any given adjustment thereof, a clamping bolt 49 is accommodated by an arcuate slot 50 formed in an extension 45a of the bracket member 45.

In the operation of preferred embodiments of the continuous centrifuge of the invention, whether vertically disposed as here shown, or otherwise, the pulp or other material to be treated is continuously fed into one end of the coiled centrifuge tube, as mentioned hereinbefore, and is discharged in separated condition at the opposite end of such tube, the heavier components discharging separately from the lighter components. Other possible constructions may, however, provide for this or for additional material introduction be apparent to those skilled in the art. Summarizing the operation of the specific construction illustrated, the pulp to be treated is introduced into the machine through the upper open end 28 of the rotating composite shaft, and passes down through section thereof and into the upper end of the elongate and coiled l0 centrifuge chamber 27 by WEB of flow portion 135 Of shaft member 13. Within the cent ifuge chamber, such material to be treated is subjected t centrifugal force active by reason of the rapid rotati n o the tube as secured in position on supporting cylinder 11. The 15 heavier or solid components are thrown outwardlypf the rotative axis of the centrifuge bowl structure of the machine, and against the inner wall 34 of the flexible rib portion 100 of the centrifuge tube. There, they are acted upon and movedwalpn the length of the centrifuge chamber 27, toward the disch nd thereof, by the advancing wave or peristaltic ammbuthe several rollers 41. The latter are adjusted into greatmr protruding flexible less indenting relationship with the rib portion 13c of the tube as the require.

As the heavier components, which tend to hug the inner wall 34 of the tube, reach the entrance 51, Fig. 3, of the discharge pocket passage 36, formed by internal partition 35', they travel down the length of such pocket and out of the discharge nipple 37, being deposited in stationary trough 39 continuously as the centrifuge bowl structure rotates.

The lighter components remain in the main passage 52 of the discharge portion of the tube, and pass out of the centrifuge chamber by way of flow passage 13b and sec tion 16 of the shaft and discharge orifice 32a of plug 32.

The degree of segregation of the components of differing specific gravities and the density of the discharge products may be varied and controlled by regulating 40 either the rate of rotation of the centrifuge bowl structure, the depth to which the rollers 41 indent the flexible rib portion 190 of the centrifuge tube, or the feed and discharge rates of the material supplied to the machine, or all of them. 45

It will be realized that the faster the centrifuge bowl structure rotates, the greater will be the tendency to throw the lighter components outwardly against the inner wall 34 of the centrifuge chamber, and to advance them to discharge along with the heavier components.

Furthermore, the deeper the rollers 41 indent the flexible outer wall of the centrifuge tube, the greater will be the tendency for lighter components to pass to discharge with the heavier components, inasmuch as the rate of travel of the heavier components to discharge is increased and less opportunity is afforded for working such lighter materials out of the traveling bed of heavier materials and into the line of flow of the lighter materials.

On the other hand, increasing the rate of material feed and discharge, and, thus, the rate of flow of material along and through the centrifuge chamber, will tend to decrease the proportion of lighter components mingled with the heavier components by reason of the lesser time given for centrifugal force to act and the greater resistance to its efiect.

in connection with the above, it should be noted that, as in the continuous centrifuge of my aforementioned pending application, the rolling over and over of the solid particles (by reason of the progressively advancing waves of the peculiar peristaltic action), in combination with the centrifugal force, promotes a high degree of classification of the solid particles. The heavier particles crowd the lighter particles away from the flexible inner wall surface 34, and bring them into the line circumstances may 25 of action of the flow of the lighter components through the centrifuge chamber.

The tube diameter will also determine, to a certain extent, the results accomplished by the machine. For example, tubes of relatively large diameter will ordinarily be best employed for processing materials containing mostly coarse particles, while tubes of relatively small diameter will be employed to process materials containing mostly fine particles.

In all instances of use, the diameter and length of tube, the rate of rotation, the depth of indentation, and the through-put rate will be selected and controlled ,with a view toward the particular material to be processed and the nature of the results desired.

The coiled centrifuge tube provides a particularly advantageous centrifuge chamber, in that, among other things, it elongates the zone of centrifugal action, while restricting it transversely. This means that not only is wide variation possible, but that, generally speaking, the centrifugal throw of the material is decreased over conventional centrifuge chambers, while the path of centrifugal action is extended.

This feature of the invention is not only of importance in connection with the flexible rib and transportative wave action of the particular embodiment shown, but can beapplied to advantage in the construction of continuous centrifuges generally.

Whereas this invention-is'here illustrated and described with respect to a particular preferred construction thereo, it should be understood that various changes and various other construction are possible within the scope of the concepts here taught and defined in the claims which follow.

I claim: 1

1. A continuous centrifuge machine, comprising an elongate tube coiled about a rotative axis, said tube defining a centrifuge chamber internally thereof and having at least, that longitudinally extending portion thereof which faces outwardly from said rotative axis formed of flexible material; supporting means for said tube; means mounting said supporting means for rotation about an axis coincident with the said rotative axis of the tube; means for rapidly rotating said supporting means; means for feeding material to be processed into said tube; means for separately discharging from said tube segregated components of the said material fed into and processed within said tube; and means for transversely indenting the said flexible portion of said tube at multiple locations along the length of the tube as it rotates.

2. A continuous centrifuge machine, as set forth in claim I, wherein the material feeding means is disposed at one end of the tube; and wherein a pair of outlets separated transversely of the tube at the other end thereof provide the segregated components discharge means.

3. A continuous centrifuge machine, as set forth in claim 2, wherein the pair of outlets is provided by a longitudinal partition in the tube adjacent the said other end of the latter, said partition terminating against the outwardly facing portion of the tube to define a closed pocket thereat, and an opening from said closed pocket to the exterior of the tube.

4. A continuous centrifuge machine, as set forth in claim 3, wherein a dependent nipple defines the opening from the closed pocket to the exterior of the tube.

5. A continuous centrifuge machine, as set forth in claim 4, wherein there is additionally provided an annular trough below the nipple and in registry with its path of rotation.

6. A continuous centrifuge machine, as set forth in claim 1, wherein the tube is coiled helically about the tube supporting means, which extends longitudinally thereof as a backing therefor, said means being provided with receiving formations of helical characterjswithin which the tube isfirmly secured. a

7. A continuous centrifuge machine, as set forthi claim 6, wherein the mounting means for the tube sup porting means aligned, hollow shaft structures, between which the said tube supporting means is rigidly secured, and comprises, further, a structural framework in which the said shaft Comprises pp y Elxtellding 1 5 structure to the said hollow shaft structures.

structures are provided with respective slideway members for removably and replaceably receiving the tube supporting structure; and wherein fastening means removably secure opposite ends of said tube supporting 9. A continuous centrifuge machine, as recited in claim 1, wherein the means for'siipporting the tube com- "prises a rigid backing cylinder having ahelical channel structures are mounted for rotation; wherein the mateformed about and extending longitudinally of its exterrial feeding means includes a flow connection between the hollow interior of one of said shaft structures and one end of the tube; and wherein the segregated components discharge means includes a flow connection between the hollow interior of the other of said. shaft structures and the opposite end of the tube, and a separate 15 outlet contiguous to the outer portion of said tube.

8. A continuous centrifuge machine, as set forth in claim 7, wherein the tube supporting means constitutes a structure independent of the hollow shaft structures,

and wherein mutually opposed ends of said hollow shaft 20 1o nal ircumferential surface; and wherein the tube is a rubber hose fitted andsecured within said channel.

liReferen ces"Cited in the file of this patent ,"UNITED STATES PATENTS Bradbury Oct. 22, 1912 Brock Nov. 15, 1938 Leia "WLW/ FOREIGN a tams

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