US2173136A - Refrigerating apparatus and method - Google Patents

Description

' 9, 1939. a. F. RANDEL:

- REFRIGERATING APPARATUS AND IETHQD Filed Oct. 10, 1936 v 4 Sheets-Sheet 1 INVENTOR @o FOLKE RANDEL ATT IQNEY Sept. 19, 1939.

B. F. RANDEL REFRIGERATING APPARATUS AND IE'I'HOD Filed Oct. 10, 1936 4 Sheets-Sheet 2 TNVEN LKE'FMNDEL 7 ATTOR Sept. 19, 1939.

B. F. RANDEL "2,173,136

REFRIGERATING APPARATUS AND IETHOD iled Oct. 10, 1936 4 Sheets-Sheet 3 I I I INVENTOR @0 Few: RANDEL Maw ATTORNEY 19 1939. RANDEL 2,173,136

' REFRIGERATING APQPARATUS AND lax-50D Filed Oct. 10, 1936 4 Sheets-Sheet 4 INVENTOR g0 FQLKER VEL QM ATTORNEY Patented Se als, 1939 UNITED STATES PATENT OFFICE 3 Claims.

(Granted under the act of 'March a, 1883, as amended April 30, 1928; 370 0. G. 757) The present invention relates to a method of and apparatus for refrigerating, and ,it has a particular relation to a system in which an inert gas is employed for neutralizing the pressures. One of the objects of the invention is the pro-' vision of a method of and apparatus for refrigerating wherein an evaporating medium is circulated through the refrigerating system by generating a heated vapor and projecting the same into the path of the evaporating medium so as to propel this medium over a refrigerating and an absorbing liquid.

Another object of the invention is the provision of a refrigerating apparatus which employs a refrigerating liquid, an absorbing liquid, an inert pressure equalizing gas forevaporating the former and transferring it to the latter and a heated vapor for circulating the gas over said liquids. A further object of the invention is the provision of improved means for reducing the temperature of a refrigerating chamber. 7

With these and other objects in view, as well as other advantages that may be incident to the use of the improvements, the invention consists in the parts and combinations thereof hereinafter set forth and claimed, and with the understanding that the several necessary elements constituting the same may be varied in proportion 30 and arrangement without departing from the nature and scope of the invention, as defined'in the appended claims.

In order to make the invention more clearly understood, there are shown in the accompanying 35 drawings, means for carrying the invention into practical use, without limiting the improvements in their useful application to the particular construction', which, for the purpose of explanation, have been made the subject of illustration. 40 In the accompanying drawings:

' Fig. 1 is a diagrammatic view of an apparatus for providing the motive force required to circulate an inert pressure equalizing gas through a refrigerat ng system by generating a heated vapor 45 and projecting the same into the path of the gas; Fig. 2 is a similar view of a modified form of apparatus for circulating the gas;

Fig. 3 is a diagrammatic view of a refrigerating system embodying the invention;- 50 Fig. 4 is a similar view of a still further embodiment of the invention; I

Fig. 5 is a diagrammatic view illustrating the invention as applied to a refrigerating cabinet;

Fig. 6 is an enlarged transverse sectional view 55 through the refrigerating coils:

Fig. 7 is a diagrammatic view of a still further embodiment of the invention; and

Fig. 8 is a transverse sectional view taken on line 8-8 of Fig. 7.

Referring to the drawings, and particularly to 5 Figs. 1 and 2 thereof, an apparatus for generating the motive force is shown as comprising a boiler 12 containing a liquid III which is heated in some suitable way, so as to vaporize the same. The

vapor rises through a pipe H and passes into a 10 I vapors passing through the condenser 0 will attain a certain velocity, and if there was present another vapor, such as an inert or a noncondensible gas as hydrogen or nitrogen, the molecules of the vapor of the motive medium will act 1 upon the molecules of the other gas and by imp ct cause a closed circulation of this gas downwardly through the condenser and thence upwardly through a pipe I8 which is located exterior of the condenser and which communicates therewith adjacent to its upper and lower ends. The principle is very similar to so-called mercury vapor or molecular pumps, which are used in vacuum practice. This vapor or noncondensible gas will thus cause a motion of the other gas down: wardly through the condenser c and thence up through the pipe l8 back to the point where it again enters the condenser.

The motion caused is entirely independent of other forces as difference of specific weight or ejector force. The direction may therefore be in any direction, upwards, downwards, or horizontal.

In Fig. 2 there is illustrated an arrangement for imparting upward vertical motion to the inert gas. The motive liquid medium is vaporized in the boiler b and pauses upwardly through tubes I9 and 20 into the condenser c where it is cooled by water in a jacket 2| through which a cooling medium 'is circulated from an inlet pipe II to a discharge pipe 22. In the tube 20, the molecules of the motive vapor act upon the molecules of the gas so as to drive the same upwards through the condenser c, where the motive vapor is liquefied to flow back into the boiler 22 through a pipe 22'.

The gas will continue to flow through a pipe 23 into the tube 26, and thence back into the condenser c. It should be understood that it is not intended that any great differences of pressure shall. occur. The pressures are practically the same throughout, the intent being to simply cause circulation of the gas against virtually no resistance.

In Fig. 3 there is illustrated the application of the principle of circulation to actual refrigerating apparatus. The illustration is diagrammatic and no attempts have been made to show actual construction. In this figure a motive medium, for instance, mercury or some hydrocarbon liquid is vaporized in a boiler b and passes upwards through a pipe 24 and inlet tube 25 into a con denser c where the vapors are liquified by coming in contact with a cooling tube or coil 26. The liquid flows downwardly and collects in the lower portion 21 of the condenser from where it returns to the boiler b through a pipe 28.

Let it be assumed that the mediums entering the refrigeration process proper are ammonia as refrigerant, water as absorbent and nitrogen as inert pressure equalizing gas. Also, let it be assumed, that the liquid ammonia is contained in an evaporator e, which communicates through a loop 29 with an absorber a containing the absorbent. The evaporator and absorber are practically a continuous apparatus such as a long tube partially filled with the liquid mediums and allowing for a space above the liquids for vapors and gas to flow. This evaporator-absorber tube communicates at one end through a tube 30 with the upper end of the condenser c which in turn communicates through a pipe 3| with the evaporator e. The evaporator e, absorber a and condenser c are in fact one continuous vessel which may be a tubeof the same diameter, and having suitable loops for. trapping and separating the different liquids.

The absorber a also communicates at one end through a pipe 32 and cooling device 33 with a separator s, and at the other end through a pipe 34 with the lower end of the coil 26. This coil is located within the condenser c and its upper end communicates through a pipe 35 with the separator s, thus completing a closed circuit through which the absorbent circulates when heat is applied to the coil 26. It should be noted that the absorbent does not have to be lifted to fall byv gravity through the absorber, as the liquid levels are the same throughout. In fact, the construction of the apparatus is such as to demand a minimum of force to cause circulation. No percolator is required to lift any of the mediums to higher points.

In passing through absorber the absorbent will absorb the ammonia vapor there, so that the liquid passing over to the coil 26 is a rich solution of water and ammonia. If now the motive medium vaporized in the boiler b has a higher boiling point than the solution, this solution in the coil 26 will boil and the motive medium in transferring its heat to same will condense. Mercury, for instance, will condense very readily and will cause vaporization of the'ammonia from the solution. Many other suitable motive mediums can be used such as a hydrocarbon liquid having a higher boiling point than the ammonia water solution. Water has such a higher boilingpoint, and although it is also used as absorbent it could be used as a motive medium. In this case, although of the same nature as the absorbthe pipe 36 acting as a rectifier and the pipe 3] asa condenser. Liquid formed in the pipe 36, flows back into the separator 8, while condensed ammonia flows into the evaporator e. The liquid formed in the rectifier 36 may also be allowed to be trapped and caused to flow into the pipe 34, so as to again'pass through the coil 26 without passing through the absorber a.

The flow of motive vapor through the condenser 0 causes the flow of the inert gas from the pipe 25, through the condenser c, pipe 3|, evaporator e, pipe 29, absorber a and pipe 30 back to the condenser c. In passing through the evaporator e the gas picks upv vaporized ammonia, causing a reduction in temperature, and carries it into the absorber a where it is transferred to the absorptionliquid flowing therethrough in an opposite direction, the free inert gas passing again to the condenser c.

In Fig. 4, I illustrate still further a development of the invention. For the sake of simplicity, the different tubings are-indicated by single lines. The motive medium is vaporized in the boiler b as before, the vapors rising through a pipe 38 into the condenser c. The vapor is condensed by passing the heat of vaporization to the solution in a coil 39 located in the condenser, ammonia vapors and water liquid rising through pipe 40 into the separator s. Ammonia vapor passes upwardly through a pipe 4| and into a refrigerant condenser c, where it is liquefied. From the condenser c the liquefied ammonia flows through a pipe 42 into the evaporator e. In order to prevent liquid refrigerant from escaping from the evaporator e, the ends of the tube terminate in loops 43 and 44.

In passing through the condenser c, the motive vapor will cause motion of the inert gas, such as nitrogen, down through the condenser, thence upwardly through a pipe 45, thence over loop 46 and into the absorber a. From the absorber the inert gas passes upwardly through a pipe 41 and over the loop 44 into the evaporator e, thence over loop 43 and downwardly through a pipe 48 back to condenser c.

The weakened solution collecting in the separator s will flow through a pipe 49to the absorber a and thence through a pipe 50 into the lower end of the coil 39, thus completing its circulation. The loop 46 will prevent motion in the reverse direction.

In passing through the absorber a, the solution will be enriched by absorbing the ammonia from the mixture of ammonia and nitrogen. The medium thus entering'evaporator e from the absorber a is substantially pure nitrogen, and this gas will cause evaporation of the liquid ammonia,

- thus causing refrigeration.

It should be noted that the absorber and evaporator constitute a continuous tubing, the evaporator entering refrigerator cabinet 1' at right angles from the absorber a, which preferably is located on the back of the cabinet, as shown in Fig. 5. The absorber a is located below the evaporator e, but it may also be located on the same level, or at a higher level than the evaporator.

In Fig. 5 there is illustrated an apparatus wherein the evaporator e and absorber a are located on the same level. In this figure only the evaporator and the absorber are shown, the other parts being similar to the arrangement shown in Fig. 4. The absorber a is located at the rear of a cabinet 1' and the evaporator e is located at right angles thereto, projecting inside of the cabinet. Vapors enter through a pipe 5| leading to the loop 44 and pass out through a pipe 52 leading to the loop 43. Liquid ammonia enters through pipe 49. Solution enters through the pipe 42 and discharges through pipe 52. The loop 44 prevents solution from coming in con tact with liquid ammonia. The entire apparatus is onecontinuous tube, forming suitable coils, to present large surfaces of liquids.

Fig. 6 shows a section through the above evaporator. The tubes 53 form the evaporator coil e, containing liquid ammonia to a certain height, allowing for vapors to pass above the surface. These coils are enclosed in a frame 54, and suitable arrangement is made to support freezing trays 55 above and below the coil e.

Fig. '7 illustrates an application of the principle to a differently constructed apparatus. The motive medium is vaporized in a boiler b, the vapors pass upwards through a pipe 56 and enters the, upperportion of the condenser c. The generator 51 contains a rich solution which is boiled by the hot vapors of the motive medium. Absorbent and refrigerant vapors rise in the generator 51 to the separator s, the weak solution passing through a pipe 68 into an absorber a. The refrigerant vapor passes upwards through a pipe 59 to a refrigerant condenser c, the liquid refrigerant entering an evaporator e.

The evaporator is made of two shells till and GI, arranged in coaxial spaced relation and together defining a refrigerating chamber surrounded by an evaporator space. These shells may be cylindrical as shown, or rectangular, oval, square, etc. The inner shell is formed with a longitudinally extending well 62 (Fig. 8), into which the liquid refrigerant is discharged. This liquid will overflow the well and run downwards hugging the outer surface of the inner shell in the form of a thin film. I

An inert gas enters an inlet pipe 63 located at the low part between the two shells, and passes upwardly through the space around the shell and discharges therefrom through a pipe 64. In passing upwards the refrigerant, being presented to same in a thin film on the inner cylinder will evaporate and form a mixture of vapors. This evaporation. will remove heat from the freezing trays 65, sliding in on suitable shelves 66. Be-

tween the two cylinders may be placed ribs to separate same and to conduct heat from the chamber into the evaporator.

The mixture of inert gas and refrigerant vapor flows through pipe 64 into the absorber a, fitted with suitable splashtrays 61. The weak absorbent liquid will pass from the separator s into the .absorber a through a pipe 68 and will absorb the refrigerant vapor, allowing inert gas only, or substantially so, to pass through pipe 69 into the condenser c. The action in this condenser to cause the general flow of fluids is similar to the action described heretofore.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the thereon ortherefor.

payment of any royalties space to circulate an inert gas over a supply of liquid refrigerant to evaporate and entrain the same, thence over a supply of liquid absorbent'to transfer the vaporized refrigerant thereto, and thence back over said supply of refrigerant in a closed circuit; heating the absorbent by said a heated motive vapor to vaporize and liberate the refrigerant absorbed thereby; condensing the vaporized refrigerant thus liberated and returning it to said supply of refrigerant; and returning the absorbent free of refrigerant to said sup,-

ply of absorbent.

2. A refrigerating apparatus comprising an evaporator for containing a supply of liquid re,-

frigerant; an absorber communicating with said evaporator for containing a supply of liquid absorbent, said evaporator and absorber also containing an inert gas; means for projecting a heated vapor into the path of the inert gas to propel said gas over the refrigerant and absorbent to evaporate the same and to transfer it to the absorbent; means communicating with said absorber below the liquid level of the absorbent therein and heated by the heated vapor for heating said absorbent and refrigerant absorbed thereby to vaporize and liberate the latter; means for condensing the liberated refrigerant and returning it to said evaporator, and means for returning the absorbent free of refrigerant to said absorber.

3. A refrigerating apparatus comprising an evaporator for containing a vaporizable refrigerant; an absorber communicating with said. evaporator for containing a liquid absorbent; a first condenser communicating with said absorber and said evaporator and forming therewith a closed circuit, said evaporator, absorber and first condenser containing an inert gas; a first boiler disposed within said first condenser and communicating with said absorber below the liquid level therein; a. separator communicating with said first boiler and with said absorber below the liquid level therein; a second condenser communicating with said separator and with said evaporator; a second boiler for containing a supply of liquid motive-medium and communicating with said first condenser above and below the fluid level therein and forming therewith a closed circuit; and means for supplying heat to said second boiler to vaporize the liquid motive medium therein, the vaporized motive medium passing through said first condenser to cause the circulation of said inert gas through said evaporator,

absorber and said first condenser to evaporate said refrigerant causing cooling and to transfer the same to said absorbent and transferring its heat to said first boiler to cause the circulation of the absorbent through said absorbeigflrst boiler

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