US2281254A - Apparatus for washing impurities from gas - Google Patents

Description

April 2 8, 1942. A. w. ANTHONY, JR

APPARATUS FOR WASHING IMPURITIES FROM GAS Filed Sept. 17, 1940 Patented Apr. 28, 1942 APPARATUS FOR WASHING IMPURITIES FROM GAS Waltham, Mass., assignor Alfred W. Anthony, Jr., to Pease, Anthony E quipment Company, Cambridge, Mass, a corporation of Massachusetts Application September 17, 1940, Serial No. 357,105

3 Claims.

The present invention is concerned with improvements in the type of apparatus disclosed in the prior patent to Pease No. 1,992,762, dated February 26, 1935.

It is the purpose of this general type of apparatus as disclosed in the Pease patent to promote an intimate gas and liquid contact for the purposes of removing impurities, solid or otherwise, present in the gas, and providing extended surface for chemical or mechanical interaction. This is accomplished mainly by imparting a whirling or spinning velocity to the gas as it rises in the treating chamber, and delivering into the rising body of gas centrally thereof a finely divided liquid spray which is caused to partake of the spinning velocity of the gas and work outwardly to the boundary of the treating zone. The delivery of this liquid to the gas body generally takes place at the lower portion of the treating zone, and I have found that there may be some tendency, particularly when a reduced volume of gas is delivered to the chamber, for a certain percentage of the finely divided liquid droplets to carry upwardly along the axis of the delivery zone and thence outwardly without making intimate contact with the surrounding spinning gas body.

I have discovered that through the provision of a diverting surface located in the central or delivery portion of the treating zone and above the region of liquid delivery, I can divert the rising column of finely divided liquid sufiiciently to cause the liquid droplets to partake of the spinning velocity of the surrounding gas body, which then engenders suflicient the droplets outwardly to the edge of the zone, where the liquid droplets strike the surrounding wall of the zone.

For the accomplishment of my discovery I have found that a generally conical diverting surface of a diameter not greater than half the diameter of the treating chamber and located centrally thereof, will satisfactorily divert a col umn of droplets suificiently to cause an outward spinning or traverse through centrifugal force to the outer boundaries of the gas body.

In-the accompanying drawing illustrating the p'fiferred form of my invention, Fig. 1 represents a section in elevation of a scrubbing tower embodying my invention; Fig. 2 is a section on the line 22 of Fig. 1; and Figs. 3 and 4 are sectional views illustrating slight modifications of the diverting surfaces.

The illustrated embodiment of the invention is shown in connection with a scrubbing tower or energy to spin the like of the general nature disclosed in the Pease patent above referred to. Such a scrubbing tower has a circular casing l0, elongated in the direction of its axis and upright in its working position. The gas to be treated is admitted through a conduit l2, having a tangential admission I 4 adjacent the lower end of the treating chamber, and serving to admit gas in such a manner as to cause a generally whirling or revolving motion of the gas body which progresses upwardly and finally emerges through the central outlet I6, as indicated somewhat by arrows in Fig. 1. The scrubbing liquid is admitted through a pipe 28, which connects with a centrally disposed spray column 20, having a series of spray nozzles 22 which serve to deliver substantially along the axis a great quantity of finely divided droplets. It may be stated that the division of this spray is so fine that it is not possible under ordinary conditions to precipitate the spray by virtue of its initial momentum completely across the gas body to the wall of the treating chamber. However, the spray in its finely divided condition is picked up and entrained in the revolving gas body, and through centrifugal force thereby engendered works outwardly, causing a complete and intimate contact with the gas body, and finally engaging with the wall of the chamber.

In this type of structure, and depending upon the volume. of gas treated with relation to the size of the treating chamber, there may be a small volume of spray-laden gas which clusters about the axis, and which does not traverse the gas body to accomplish its intended function. This small volume of spray under normal conditions works upwardly, remaining in the center of the chamber where the spinning velocity of the gas is so low as not to engender any substantial centrifugal force in the liquid, finally emerging through the outlet in the form of entrainment.

This objection I obviate in a very simple manner, by providing a disk 30 located axially of the treating chamber and having a diameter approximately one-third to one-half of the diameter of the treating chamber. This disk may be supported at intervals by brackets 32, extending from the wall of the treating chamber and/or by a centrally disposed post 34, as indicated in Fig. 1. The under surface of the disk diverts this rising column of liquid spray outwardly to a point where the spinning velocity of the gas body will create sufficient centrifugal force upon the spray particles themselves to work them outwardly to the wall of the treating chamber. In

actual practice, I find that there is a concentration of wetness in the form of a ring on the wall of the treating chamber about and slightly above the surface of the disk when the diverting surface is employed, showing that such spray as would otherwise pass upwardly through the outlet at low gas loadings, is diverted and precipitated on the wall of the chamber and eventually passes down and outwardly through the waste 40.

In Figs. 3 and 4 I have shown a slightly modifled form of such a diverting surface, in both cases the diverting surface, instead of being that of a flat disk, is an outwardly flaring cone 50, supported in the same manner as previously described, and serving to divert axially moving liquid particles. The structure shown in Fig. 4 differs from that in Fig. 3, as the diverting surface 50 may be surmounted by a similar but reversed conical surface 52 to close the space within the diverting surface. In either case the surface functions in much the same manner as the flat disk-like surface to divert these flne particles of liquid outwardly to zones of higher tangential velocity, which spin them to the wall of the chamber.

In this connection it is understood and must be appreciated that the prime function of the diverting surface is in connection with a treating chamber where the delivery of the liquid particles to the surrounding gas body is of such a character that they cannot normally with the initial velocity imparted thereto traverse the entire body of gas, but must rely upon the spinning velocity of the surrounding gas body to pick up and impart suiiicient momentum for the desired traverse to the wall of the chamber.

What is claimed is:

1. Apparatus for gas-liquid contact, comprising an elongated treating chamber, means for imparting a spinning velocity to the body of gas within the chamber, means for delivering centrally of the spinning gas body a spray of liquid divided into droplets preponderantly so fine as to be incapable of traversing the gas body through their initial momentum, and means for interposing centrally of the chamber above the delivery of the liquid spray a diverting surface of a diameter of about one-third to one-half the diameter of the chamber in a position to divert outwardly an axially rising cloud of droplets which otherwise would pass through the outlet without traversing the gas body, the chamber being substantially unobstructed in the space surrounding said surface.

2. Apparatus for gas-liquid contact, comprising an elongated treating chamber of generally circular cross-section, means for introducing gas tangentially of the chamber at one end thereof, axially located means for introducing a spray of finely divided droplets into the central portion of the gas body, the numerical preponderance of the droplets being incapable through their initial momentum to traverse the gas body to the margin of the treating zone, and a divertting disk located axially of the treating chamber and beyond the liquid spray, the surface of the disk being adapted to divert that portion of the spray confined to the axis of the treating chamber outwardly to a point at which centrifugal force acts upon and causes the spray to traverse the gas body to the margin thereof, the chamber being substantially unobstructed in the space surrounding said disk.

3. Apparatus for gas-liquid contact, comprising an elongated treating chamber of generally circular cross-sections, means for admitting gas at one end of the chamber, means for removing treated gas from the opposite end of the chamber and centrally thereof, means for delivering a plurality of sprays of liquid axially of the chamber and near the end at which the gas is introduced, and a diverting disk of about onethird to one-half the diameter. of the chamber located axially of the chamber and interposed between the spray device and outlet, to outwardly divert the finely divided liquid to the zones of higher rotational velocities of the gas, the chamber being substantially unobstructed in the space surrounding said disk.

ALFRED W. ANTHONY, JR.

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