US2199258A - Dehydrator - Google Patents

Description

April 3o, 1940.

J. E. GRAY DEHYDRATOR Filed June 17, 1958 www@ am@ FIGZ.

45 Referring now more particularly to Fig. l, there known as slaked lime. Activated alumina will 45 55 gasket II.v The screen and the gasket are held line.l Thus, the refrigerant (under pressure) 55 Patented Apr. 30, i940 UNITED STATES v*PATENT OFFICE DEHYDBATOB 4'Application Junelv, 193s, serial No. 214,313

4 claims. (ci. 21o-131,)

This invention relates to dehydrators, and with in place by the circular end of the inserted regard to certain more specific features to lterhousing I. ing dehydrators for refrigerating and like The cap 5 is also provided with ribs II for supsystems. porting another similar screen I5. However, in- 5 Among the several objects of the invention may stead of using a gasket such as I1, there is located be noted the provision of a' filtering dehydrator between the circular end of the inserted body I by means of which substantially longer periods and the cap 5 a retainer ring I9 which has a rof operation may occur without clogging and cross section of generally S-shape providing an without the excessive pressure drop incident to outwardly directed flange 4 and an inwardly dil0 a clogged condition; the provision of apparatus rected flange 6. The outer fiange .4 is held by 10 of the class described which avoidsfor longer the inserted end of the body I and the inner periods, undesirable evaporation into a gas of flange 6 serves as a holder for the flange 2l of. a refrigerating liquid before the liquid reaches the ne-mesh conical screen 23, the latter also being, expansion valve; the provision of a dehydrator for example, of the order of 150-mesh. The apex of. the class described which is simple in form of the conical screenv 23 is directed upstream. 15 and consequently more economical to makeandI Its base is near the wall I so as to form a cirwhich is an improvement upon devices such as cular trough-like sump. shown in United States Patents 1,804,836, Between the screen flange 2| and the circular 1,839,350 and 1,866,659. Other objects will be in screen I5 is located a disc of standard compressed part obvious and in part pointed out hereinafter. felt 25. The disc maintains its own shape inde- 20 'I'he invention accordingly comprises the elependently and forms a .diaphragm covering the ments and combinations of elements, features of open base of the conical screen 23. Between the construction, and arrangements of parts which cone 23 and the felt disc 25 is located a mass of will be exemplified in the structures hereinafter loose, bulk felt 29. Its conical shape is deter- 25 described, and the scope of the application of mined by the conical screen 23. Both portions 25 which will be indicated in the following claims. 25 and 29 are' preferably fibrous. Other forami- In the accompanying drawing, in which is ilnous material may be used.,- lustrated one of various possible embodiments of On the outside of the cone 23 and within the the invention, body I is located dehydrating material such as :i0 Fig. 1 is a longitudinal section of, the device; lumps of activated alumina or calcium oxide 21. 30 and, 'I'he lump form of the material renders the total Fig. 2 is a side elevation. mass of it foraminous. After assembly, both Similar Vreference characters indicate correcaps 3 and 5 are soldered to the body I or othersponding parts throughout the several views of wise autogenously fastened. A suitable linethe drawing. leading from the accumulator is attached to the 35 The present invention is directed particularly adapter .1, and a suitable line is attached to the to dehydrators for use in the liquid lines of readapter 9 and leads to the expansion valve. They irigerating systems. These are generally located device may be used elsewhere in a refrigerating between the receiver and the expansion valve or system, but it is intended that only liquid refrig- 40 valves. A purpose of the dehydrator is to preerant shall flow through it. 40 vent the passage of moisture to the expansion Dehydrating agents such as those above noted valve and other parts. -In serving this purpose, partially break down into a fine powder. For the dehydrator shouldl not permit the passage example, calcium oxide, upon the addition of into the liquid line of solid particles. moisture, forms calcium hydrate, generally is shown at numeral I an elongated housing, pre'l, break down because of erosion which is due to erably made of a copper tube or the like. On rubbing of one particle against another.

this housing at one end is an inlet cap 3 having In either of the above and similar cases, the an inlet adapter 1, and at the other end an outlet small particles will clog the ordinary fine, fiat 'cap 5 having an outlet adapter 9. screen, thereby causing a pressure drop in the 50 Within the cap 3 are three ribs II, which, with refrigerant. Such pressure drop in the refrig` a shoulder I3 form a support for a fine-mesh erant is detrimental because it causes a partial inlet screen I5, for example, of -the order oievaporation of the refrigerant and consequently 'meslL Adjacent the edge of the screen is a results in delivery of gas bubbles into the liquid which, reaches the expansion valve, instead of being'l homogeneous is composed of li f d and gas bbles. `Expansion valves do no operate properly if there are gas bubbles in the liquid.

i A former solution-of the problem was to provide a more open filter', thus allowing particles to pass into the piping system. This procedure has obvious disadvantages.

'Ihe present invention operates as follows:

l The refrigerating fluid. with its entrained moisture, enters through the screen I5. Beyond thescreen it passes by the lumps of dehydrating agent 21 and during this passage has the moisture absorbed or adsorbed therefrom by uniting with -jl the dehydrating agent.

Any small particles of theA dehydrating agent that break off and become free are carried along with the refrigerating fluid. The general direction of flow of the refrigerating fluid is exempli- 1 9 fled by the vertical arrow A which carries the particles along until the screen 23 is reached. Since the very'iine screen 23 presents between its interstices only very small (if any) components of its openings in the longitudinal direction, the

small solid detachments 2 do not readily ilnd their way through and are deflected, more or less as shown by the arrow B. The straight-line characteristic of the arrow is diagrammatic. Actually, the liquid streams through the lumps of the dehydrating agent 21 in more or less sinuous contour. However, so far as the action at the surface of the screen is concernedthe arrow is illustrative.

It will be seen that the conical shape has advantages in that a sloping surface is presented by the screen, whereby liquid flow is accommodated with little interference while solid particles are deflected. At the same time, the deflected particles are guided into relatively harmlessperipheral positions.

The solid particles 2 that are deflected ultimately iind their way down to the peripheral trough-like space between the base of the cone 23 and the body I, thereby' letting the apex of the cone and the portion surrounding it free for the passage of fluid. It will be seen that there is an advantage in the fact that the free portion of the screen is centrally located, because it is in the central portions of a tube that the ilow is most free, anyway.

Although a vertical position is preferable, such as shown in the drawing, the device may be used in other positions. The operation is substantially the same, becauseg'tlie liquid flow through the device tends to maintain the separated particles more or less as indicated, even if not exactly as indicated, in Fig. l.

Very ne particles that circulate at Vthe surface ofthe screen 23,-substantially the sa e as the. so fluid, and that find their way through the screen are primarily caught by the loose felt 29. Particles that are so fine that they pass through the loose felt 29 are caught by the standard compressed felt pad 25, but, it may be observed 65 that there will be very' few of these.

The purpose of making the material within the cone of a loose fibrous structure, whereas that within the disc is of al tightly-packed fibrous structure, is that in a loose structure the blocked 70 particles tend better to distribute themselves rather than to become packed over a definite surface. apparatus will freely` transmit fluid. The tightly packed disc being behind the loosely packed ma- 7s terial within the conical screen receives only'a..

This lengthens the life during which the f vv-tively dense filtering material lon said screen, a

sacaste very small amount of comminuted material to be ltered out. Thus. it will beseen that the i to clog operation.

The tightly packed fibrous material isthen protected against clogging and serves the function primarily of removing very fine particles. These much-more slowly clog the filter than the larger `particles would, were they permitted to. enter the4 disc-of fibrous material.

Since there is (l) a tendency'for--a Vcentral portion of sceen 23 always to be free of large particles, and (2) since the relatively large mass of loose felt 29 requires a long period before clogging occurs from the few particles that mayl get through the screen, and (3) since there are only a few exceedingly line particles that reach the surface of felt disc 25, it follows that the device has a relatively long effective life during which free passage exists therethrough without excessive pressure drop.

Besides the above advantages, it will be seen that the conical screen presents a larger area so that the screen 23 may have a substantial part of its base portion completely clogged before the free area becomes less than the free area of either of screens I6.

structurally, the device has the advantage that the cone 23 is springingly held down on the disc 2l by the flanged ring I9. The natural tendency of the loose material 29 to expand when packed in place serves to insure that the space within the cone 23 remains substantially filled and Without deleterious voids. These facts eliminate the requirement of niceties in manufacture.

In view of the above, it will bev seen that there is avoided, by means of the present apparatus, the quick reduction in capacity which occurs with ordinary iine-mesh screens or materials, and at the same time the apparatus avoids the ineffectiveness of non-clogging coarse-mesh screens.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in carrying out the above constructions without departing from the scope of the invention, it is intended that allsmatter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense. c

I claim: l

1. In a dehydrator, a tubular body member having an inlet, and an outlet cap having a passage therethrough covered by a relatively iiat screen, a preformed disc ofresilient filtering material on said screen, a conical screed extending into said body member and spaced from said flat-screen and having a flange on said disc, an inwardly and outwardly flanged ring having its inward flange over the screen flange and its outward flange adapted to be held upon assembly by the body ,member and outlet cap whereby the conical screen is springingly held in position against the disc.

2. A dehydrator comprising a tubular body member having an inlet, an outlet cap for the body having a passagef'tlierethrcugh covered by a relatively at screen, a preformed disc of relaconicalnscreenspaced from said ilat screen and having a flange on the margin of said disc, an

inwardly and outwardly ilanged ring having its inward flange over the screen flange and its outward ange adapted to be held upon assembly by the body member and outlet cap, whereby the t conical screen is sprlngingly held in rposition against the disc, and relatively loose filtering material contained within the body member between the disc and the conical screen.

3. A dehydrator comprising a body portion having an inlet, an outlet cap fastened to the body portion having a passage therethrough covered by a relatively flat screen, a preformed disc of relatively dense lterlng material on said screen, a conical screen spaced from said flat screen and having a flange on said disc, an inwardly and outwardly flanged ring having its inward flange over the screen flange and its outward flange adapted to be held by said body portion and outlet cap upon assembly. whereby the conical screen is springingly held in position against the disc, and loose brous material between the disc and said conical screen, the apex of said conical screen being directed upstream with respect to the flow through the body portion, and

said body portionl being filled with a Ioraminous mass of dehydrating agent.

4. A dehydrator comprising an inlet cap, a tubular body fastened thereto, a screen disc held between said cap and body, an outlet cap fastened to the body and having a passage therethrough covered by a screen disc, a preformed disc of relatively dense felt on said screen, a projecting screen spaced'from said flat screen and having a flange on said feit disc, an inwardly. and outwardly flanged ring containing the felt disc and having its inward vflange over the screen flange and its outward flange adapted to be held upon assembly by said tubular body, whereby the projecting screen is springingly held in position against the disc, and loose fibrous material between the disc and said projecting screen, the end of said projecting screen being directed upstream with respect to the flow through the tubular body, and said body being filled with a'foraminous dehydrating mass which is contained between the first-named screen and the projecting screen.

JOHN E. GRAY.

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