US2100504A - Restricted flow refrigerant feeding device - Google Patents

Description

Nv.3o,1937. M cRQSLEY UAL' 2,100504 Rssrnlcrn FLow REFRIGERANT FEEDING'DEVIGE Filed oct. 19, 1954 iii' ATTORNEYS.

'Patented Nov.i30, 1937 UNIT-Eo STATES 2,100,504 A I :insmeren FLow aEFnrGEaANT FEED;

ING DEVICE Lewis M. Crosley and John `w. Dunn, cincinnati,

Ohio, assig'nors to Th e-Crosley Radio Corporation, Cincinnati, Ohio, a corporation of Ohio Application October 19, 1934, Serial No. 749,090

4 claims.

Our invention relates to devices adapted to feed, for example, the evaporator of an electric refrigerator with refrigerant from the condenser, and is designed to supplant the capillary tube.

l Capillary tubes have been successfully -used in re frigeration systems which were properly designed therefor to provide a continuous restricted ow oi' refrigerant from the condenser to an evaporaf Ator which was kept substantially continuously full l of the refrigerant and wasl therefore known as a :Hooded type evaporator. In an exemplary system of this type eight feet of so-called capillary tubing, whichis a relatively thick walled metal tubing of quite small internal diameter, is used. The use l5 of so much tubing involves the problem of condensing it into a suitable space, which has usually been done by coiling it at one or more places in its length. It involves also the use of a relatively great quantity of such tubing, which is essentially of high cost.

. Itis an object of our invention to provide a restricted ow device which is very much more economical of space. It is also an object of our invention to provide a device which does not involve the use of anything like the same quantity of expensive capillary tubing, but employs a very much shorter length of such tubing, if any. It is an object of our invention to provide an assembly characterized by restricted passageways using members, some if not alll of which, would notbecharacterized by small internal volume or capacity if used alone. It is another object of our invention to secure restriction by means not hitherto employed in the same or analogous uses. u These and other objects of our invention which will be set forth hereinafter, or will be apparent to one skilled in the art' upon reading these specications, we accomplish by that certain construction and arrangement of parts of which we shall now describe two exemplary embodiments, it being understood that these embodiments do not by any means exhaust the combination characterizing our invention as set forth in the appended claims.

have found that restricted lflow devices which are much more economical of space, can be constructed to advantage and with economy, by the insertion-of tubes or tube-like structures one inside the other, utilizing the space between the external diameter of the smaller tube and the internal diameter of the larger tube as the desired restricted passage-way. Thus by choosing tubes or tube-likestructures having a proper relationship of internal to external diameter, we are able Vspectively with the devices of Figs. 1 and 2.

` smallest internal tube indicated at 2, is con- Fssentially in the practice of our invention, we

vboth of these tubes there is slipped a third tube '8, one end of which is closed as at 9, by attach- (CL-13H2) in some instances, to

, and external diameters will remain the same.

lConsequently in our structures We contemplate the use of two or more tubes, one inside the other, and employ as respects these tubes, a counter-now of the refrigerant therein, as will hereinafter be more fully explained. In general within practical limits any number of tubes may be placed one inside the other. Both the number of tubes'and the space diierences between their internal-and external diameters will determine the overall length of the restricted now device. Whenl employing even numbers of tubes, theA refrigerant will be introduced and withdrawn from essentially the same end of the device. When using odd numbers of tubes the refrigerant will be introduced and withdrawn from opposite ends of the device. This is on the assumption that common ttings are used connecting with the several tubes. This, however, is not a limitation onthe broadest aspects .of our invention, inasmuch as onetube may be passed through the wall of another and soldered orwelded thereto, so that separate ttings may be employed, as will be clear.

In the drawingr- A l Figure 1 shows an embodiment of our invention employing three tubes.`

Figure 2 shows another embodiment employing two tubes.

Figs. 3 and 4 show refrigerators equipped re- In Figure 1 we have shown an exhaust tting at'l, adapted for example, to be connected to -the evaporator I1 of a refrigeration system. The

nected to this ttlng as at 3. The tube 2y has an open end ,beveled if desired, to prevent clogging. Over the tube 2 there is slipped another tube B. This Vtube has a closed end t and an open end 1, likewise beveled if desired. Over ment to the fitting and the. other end oi' which is attached to a fitting I8, so as to con` nect with the bore H thereof. The ntting Il may be thought of as connected to .thecondenser n desired, spacing means the tube 5, the

2 of an electric refrigerator, as in Figure 3. If vfor the tubes may be provided, comprising' a series of kinks yformed radialy around the tubes and spaced, for example,

120 apart, as indicated in Figs. 1 and 2 at 22.

These means, however, are not necessary to the operativeness of the structure, andmay be omitted. In the operation of this device, the refrigerant first enters and passes 8, the difference between the external diameter of tube 5 and the internal diameter of the tube 8 'forming a restricted passagewa Having passed through the tube 8 to the left-hand end therof, the refrigerant blocked by the closed end 9 of tube 8 returns through tube 5 to the righthand end o f the device. To d'o this it must pass through the space difference between the internal diameter of' tube 5 and the external diameter if the ratios of these diameters are correctly chosen, again forms a restricted passageway interposing resistance to the flow of the refrigerant. As hereinabove indicated, it makes no essential difference whether the tube 2 is centered in the tube 5 or not. Having passed through the tube 5 to the right-hand end of the device, and being .blocked by the closed end 6 of refrigerant must next travel through the tube 2 in order to reach its outlet at the fitting 3. This tube may be conveniently of small bore and may therefore provide a restricted passageway interposing a useful amount of the total resistance frigerant. However, this is not necessary and a tube 2 of relatively large internal diameter may be employed if desired, providing the-necessary resistance is built up in` other-parts of the restricted flow'device. y

The length of the device and the respective ratios of internal to external diameters of the tubes, control the amount of resistance interposed to the flow of the refrigerant. .It will be clear .that the thickness of the walls of the tubes in and of itself is not a controlling factorv as to the resistance of the system. Tubes should, of course, have sufiicient wail thickness to withstand the diil'erences between the pressure inside of them and the pressure outside of them, but beyond this limitation theirwalis may be Vthick or thin, as is through a tting vgiven even number of found convenient.

In Figure 2 we have shown a type of device emtwo tubes. Here a tube I2 lies inll, to which the outer tube is connected, and which has a side outlet member I5. The outer tube will be closed at the end which lies furthest from the fitting il, and this closed end may be provided as at It with a sump or trap for the collection of impurities or sludge, which has passed through the inner tube but might not pass through the space between the two tubes. Or the end of the tube Il may be turned over' for a like purpose.

The device of Figure 2 is Y Figure 4 where it is connected to a condenser I9 and also to an evaporator 20 `by means'of a tube 2l. i

It will readily be understood how the device of Figure 2 may be modied to include any other The combined a8'- 'perhaps 4 easiest by dressing through the tube 4as will serve to feed tothe passage of the retw'o tubes, one inside the other,

indicated at IB in semblyof tubes in either of the modiilcations may be coiled or bent or otherwise disposed in such a way' as will be found convenient in the assembly of a refrigerator. It will be understood also that the amount of restriction or resistance interposedA to the ow of refrigerant as between any two tubes may be controlled` in a variety of ways, but the outerksurface of an inner tube. Y

ModificationsV may be made in our invention Without departing from the spirit thereof.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:- s

1. A restricted iiow of device comprising at least two tubes, one inside the other, said tubes being of substantial length and means at the end thereof for introducing uid and for causing said fluid to traverse a path which comprisesl the bore of one tube and the space between said tube and the other tube for substantially the entire length of said device, said path being of'such dimensions an evaporator from a condenser in a mechanical refrigerator, and maintain an appropriate level of refrigerant therein. n

2'. A restricted flow device comprising at least two tubes, one inside the other, said tubes being of substantial length and means at the end thereof for introducing fluid and`for causing said fluid to traverse a path which comprises the'bore of one tube and the space between said tube and the other tube for substantially the entire length of said device, the number of said tubes so assembled being odd, and means at opposite ends of said assembly for introducing and withdrawing a fluid, said path being of such dimensions as will serve to feed an evaporator from `a condenser in a mechanical refrigerator, and maintain an appropriate level of refrigerant therein.

3. A restricted flow device comprising at least said tubes being of substantial length and means at the end thereofffor introducing fluid and for causingwsaid fluid to traverse a path which comprises the bore of one tube and the space .between said tube and the 'other tube for substantially the entire length of said device, the number of said tubes being even,

and. means'. at 'one end drawing a` fluid'.said path being of such dimensions as will serve to feed an evaporator-from.

condenser in a mechanical refrigerator. and4 maintain an appropriate therein.

level of refrigerant 4. A restricted ow devicel comprising a plurality of substantially concentric tubes, alternate tubes being closed at alternate ends and means for introducing and withdrawing a fluid from said assembly, such that said fluid is caused to pass in alternate directions through lsaid assembly in paths comprising the internal space of each of said assembly for with-

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