US2536274A

US2536274A - Desiccant cartridge and method of making

Info

Publication number: US2536274A
Application number: US723591A
Authority: US
Inventors: Richard S Gaugler
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1947-01-22
Filing date: 1947-01-22
Publication date: 1951-01-02
Anticipated expiration: 1968-01-02

Description

Jan. 2, 1951 R. s. GAUGLER 2,536,274

DESICCANT CARTRIDGE AND METHOD 0F MAKING Filed Jan. 22, 1947 INVENToR.

i I BY ,Mk

Patented Jan. 2, 1951 DESICCANT CARTRIDGE AND METHOD OF MAKING Richard S. Gaugler, Daytonkphio, assignor to General Motors Corporation, Dayton, Ohio, a

corporation of Delaware Application January 2z, 1941, semi No. 723,591

4 Claims.

This invention relates to refrigerating apparatus and more particularly to an improved drier unit for use in refrigerant circuits and to an improved method of making the drier unit.

It is an object of this invention to provide a low cost drier unit or desiccant cartridge which is not subject to breakage when handled roughly.

It is another object of this invention to provide an improved method and apparatus for manufacturing drier units of uniform size.

It is another object of this invention to provide drier units of uniform size in which granular particles of a desiccant material are compactly arranged within an outer perforated casing.

VFurther objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawing:

Figure l is an elevational view showing a woven wire tube of the type used inthe manufacture of the drier unit;

Figure 2 is an elevational view with parts broken away showing apparatus used in the manufacture of the drier unit and showing one drier unit in the process of manufacture;

Figure 3 is an elevational view of a ldrier unit; and,

Figure 4 is a sectional view taken on line 4-4 of Figure 3 showing the arrangement of the spiral reinforcing wire within the woven wire tubing which forms the outer casing of the unit.

This application is related to application S. N. 697,980, filed September 19, 1946, wherein there is shown and claimed one form of drier unit.

It has been found desirable to maintain complete uniformity in the outer dimensions of the drier umts and to make them sufficiently rigid so that the likelihood of breakage during rough handling will be largely or entirely eliminated. Both of these desirable objectives are accomplished by my invention as set forth more fully hereinafter.

The outer casing of the drier unit is made by taking a section of expansible woven wire tubing Il, such as shown in Figure 1 of the drawing, and twisting the lower end of the tubing as indicated at I2 in Figures 2 and 3 and then inserting this into a sizing tube or fixture I4 having an internal diameter substantially equal to the desired external diameter of the finished drier unit. As shown in the drawing, the tubing Il) consists of interwoven wires extending helically in opposite directions.

(Cl. 21o-131) In order to expand the woven wire tubing to the desired diameter, pressure is first applied to push the upper end toward the lower end of the tubing and then a helically wound relatively stiil' wire I6 is forced into the upper end of the tubing while the tubing is mounted within the fixture I4. Woven wire tubing of this type may be purchased cheaplyvand comes in long lengths of small divthe funnel 20.

The fixture I4 is vibrated by means of the vibration producing element 22 while the loose granular material is being fed into the tubing I0 so as to cause the granules to be packed in place. Since vibration producing elements are old and well known, and since the details of construction of the vibrating element are immaterial they need not be shown or described in greater detail.

After the tubing I0 has been filled to the desired level, the upper end of the tubing'is twisted as indicated at 24 in Figure 3 so as to close the upper end of the tubing. Closing the tubing against the ends of the wire I6 and the desiccant I8 prevents foreshortening of the tubing thereafter. Any dust which may result from abrasion of the particles during the filling operation may be blown off, if desired, during or subsequent to the filling operation. The aembly is thereafter removed from the fixture I4 andis coated with a moisture permeable, moisture insoluble but dustproof material.

Preferably granular4 anhydrous calcium sulphate is used as the desiccant, although other materials such as lime, silica gel, or other alkaliv earth oxides may also be used. The coating ma- V terial which I prefer to use is cellulose acetate,

' although other materials such as ethyl cellulose, methyl cellulose, or any oi. the hydroscopic coatings of cellulose esters or ethers, may be used depending upon the particular application. Thus in a refrigerating system employing Freon refrigerant, it is preferred to use anhydrous calcium sulphate granules coated withvcellulose acetate so as to completely enclose the anhydrous calcium sulphate whereby fine particles of calcium sulphate are prevented from passing through the coating. l

The coating operation may be performed by sat urating the entire assembly comprising the screen tubing Il, the reinforcing helical wire IB and a granular desiccant material Iii,v with a ve to ten percent solution of celluloseacetate and thereafter allowing the excess solution to drain oi from the assembly so as to leave a porous structure. Theassembly may be saturated in any manner such as by dipping it into a liquid solution of a coating material or by placing the assembly in a vessel, evacuating the vessel of air. replacing the evacuated air with the liquid solution so as to fill all of the voids, and thereafter removing the assembly from the vessel and allowing the excess solution to drain off leaving only a. thin cohesive binding coating on the parts. Woven wire tubing material which will provide approximately a 16-mesh screen closure for the desiccant material is preferably used.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows:

1. A cohesive drier unit of large effective surface area comprising a perforated casing; a hellcal-shaped reinforcng member within said perforated casing contacting and supporting the inner wall of said casing to prevent its collapsing and crushing; a granular desccant material within ,said casing; and a binding coating for said granular desiccant material, said reinforcing member, and said casing comprising a moisture permeable, moisture insoluble but dustproof combined binding and coating material; said coating serving to bond said granular desiccant, said re'nforcing member and said casing into a unitary cohesive structure.

2. The method of fabricating a drier unit of the type in which a desiccant material is disposed within an expansible woven wire tube which comprises closing one end of said tube, expanding said tube while confined within a fixture having an internal diameter substantially corresponding to the nal external diameter of said drier unit, placing an expander element within said tube for establishing the internal diameter of said tube, placing granular desiccant material within the tube, closing the other end of said tube and thereafter applying a moisture permeable, moisture insoluble but dustprooi' binding coating to the exposed surfaces of said desiccant material and said tube.

3. In combination, a flexible woven wire tube element having helically extending interlaced l 4 wires, a rigid helical wire within said tube limiting inward exing of said tube element, said tube element having closed end-portions engaging the ends of said spiral wire so as to prevent foreshortening of said tube element, desiccant material within said tube element, and a coating of water permeable bonding material on the surface of said desiccant material and said helical wire and said woven wire tube element for increasing the rigidity of the assembb'.

4. The method of fabricating a drier unit of the type in which a desiccant material is disposed within an expansible woven wire tube which comprises closing one end of the tube, expanding the tube to the desired nal diameter of the drier unit, placing an expander element within said tube for establishing the minimum internal diameter of the tube, vibrating the tube and expander element while placing granular desiccant material within the tube, closing the other end of-the tube, and thereafter applying a thin moisture permeable moisture insoluble dustproof binding coating to the entire assembly including the entire surfaces of the desiccant material andthe expander element and said tube to bind the as- The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 913,325 Touzimsky Feb. 23, 1909 1,137,480 Gwynn Apr.- 27, 1915 1,218,975 yBrison Mar. 13, 1917 1,704,634 Snider Mar. 5, 1929 1,839,350 Slagel Jan. 5, 1932 2,175,775 Hum Oct. 10, 1939 2,203,815 Dahl et al June 11, 1940 2,260,608 Cormack Oct. 28, 1941 2,267,918 Hildabolt Dec. 30, 1941 2,365,149 Anderson Dec. 19, 1944 2,388,390 Cook et al. Nov. 6, 1945 2,433,531 Ryan Dec. 30, 1947 FOREIGN PATENTS Number Country Date 100,667 Australia Apr. 15, 1937 OTHER REFERENCES Mercks Index. 4th edition, 1930, Merck 8; Co. Inc., Rahway, N. J., p. 155.