US2724246A

US2724246A - Method and means for improving the utilization of volatile refrigerants in heat exchangers

Info

Publication number: US2724246A
Application number: US420395A
Authority: US
Inventors: Charles E Lowe
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-04-01
Filing date: 1954-04-01
Publication date: 1955-11-22
Anticipated expiration: 1972-11-22

Description

Nov. 22. 1955 c. E. LOWE 2,724,246

METIZOD AND MEANS FOR IMPROVING THE UTILIZATION OF VOLATILE REFRIGERANTS IN HEAT EXCHANGERS Filed April 1, 1954 6 Sheets-Sheet l LB 5 (r3 (1) & INVENTOR. CHERJJES 12. ow

PXTTORNYCY NOV. 22, 1955 c, E, LOWE 2,724,246

METHOD AND MEANS FOR IMPROVING THE UTILIZATION OF VOLATILE REFRIGERANTS IN HEAT EXCHANGERS Flled April. 1, 1954 6 Sheets-Sheet 2 mnmw ME I m 2m M M NW C RT TO RN TzY NOV. 22, C. E. LOWE METHOD AND MEANS FOR IMPROVING THE UTILIZATION OF VOLA'IILE REFRIGERANTS IN HEAT EXCHANGERS Filed April 1, 1954 6 Sheets-Sheet I5 FIGES.

Li INVENTOR. ,1 cHf-iRLEs 32.);ow

fTTORNEY NOV. 22, 1955 c E LOWE 2,724,246

METHOD AND MEANS FOR TMPROVING THE UTILIZATION OF VOLATILE REFRIGERANTS IN HEAT EXCHANGERS Filed April 1, 1954 6 Sheets-Sheet 4 IN V EN TOR. CiHBRLES 2. LOWE,

FIGA.

BTTORNEY Nov. 22, 1955 c. E. LOWE 2,724,246

METHOD AND MEANS FOR IMPROVING THE UTILIZATION OF VOLATILE REFRIGERANTS IN HEAT EXCHANGERS Flled ApIlL l, 1954 6 Sheets-Sheet 5 INVENTOR. RLfi E- L E ETTORNEY Nov. 22, 1955 C. E. LOWE METHOD AND MEANS FOR IMPROVING THE UTILIZATION OF VOLATILE REFRIGERANTS IN HEAT EXCHANGERS Filed April 1. 1954 FIG. 10.

6 Sheets-Sheet 6 INVENTOR. HARLES E.LOWEJ :BTTORNEY i United States Patent O METHOD AND MEANS FOR IMPROVING THE UTILIZATION OF VOLATILE REFRIGERANTS IN HEAT EXCHANGERS Charles E. Lowe, Orlando, Fla.

Application April 1, 1954, Serial No. 420,395 11 Claims. (Cl. 62115) The present invention relates to heat exchange systems employing a volatile refrigerant liquid and which may be used for the heating or cooling of water, air, or of other gases or liquids, ,as in heat-pumps, refrigeration, air-conditioning or ice-making apparatus or the like, and is concerned more particularly with the more efficacious employment of the refrigerant in an evaporator or workperforming ,heat exchange instrumentality. This application is a continuation-in-part of my co-pending application, Serial No. 314,364, filed October 11, 1952.

Heretofore, and so far as is known, insystems employing heat exchangers of the evaporator type-into which a volatile refrigerant is discharged for contact with tubes, coils or other surfaces to effect a heat-exchange therebetween and thus vaporize the refrigerant into a low-pressure fluidthe normal charge of refrigerant is such as to substantially flood the evaporator or to have a substantially large quantity of the liquid refrigerant retained in the bottom portion of the evaporator during the operational cycle. This has resulted in very slow and sluggish vaporization of the refrigerant with an accompanied inefliciency in the output of the heat exchanger unit.

Attempts have been made to overcome this situation by introducing the liquid refrigerant at the sides or at the top of the evaporator or by the employment of baflies to guide and direct the refrigerantall for the purpose of causing the liquid refrigerant to flow over the surfaces of the evaporator to better absorb the heat therefrom and to vaporize. Another such attempt has been to introduce a portion of the high-pressure liquid refrigerant through jets and/ or injectors into an evaporator flooded with low pressure or expanded liquid refrigerant for the purpose of creating a circulating movement of the liquid refrigerant within the evaporator, as in United States patents to Phillips No; 2,123,021 or to Boileau No. 2,132,932. These attempts to improvevaporization of the liquid refrigerant in, so-called, flooded systems could have theoretically some beneficial results in given circumstances, but, so far as I know, they are not employed, Further, it has been proposed to by-pass a portion ofthe high-pressure gaseous refrigerant from the compressor of the system to act as the impellent for aspirating low-pressure or expanded liquid refrigerant in an evaporator, as in United States Patent No. 2,159,251, thus short cycling part of the capacity of the compressor or other refrigerant pump.

Furthermore, prior to my invention, heating and cooling systems of the reversible type, wherein there is a heatexchanger that serves as a condenser on the cooling cycle and as an evaporator on the heating cycle, the charge of refrigerant in the system is controlled by that required for the cooling cycle and which, usually is more than required for the heating cycle. Nevertheless, during the heating cycle in such a system, the greater portion of liquid refrigerant, discharged into the evaporator (usually through an expansionvalve), does not quickly vaporize but flows into and remains on the bottom of the evaporator and is not sufiicient in volume to properly flood or contact the heating surfaces of the evaporator so as to be 2,724,246 Patented Nov. 22, 1955 vaporized to best advantage, thus resulting in slow and inefficient vaporization. To increase the amount of the refrigerant charge above that required or permissible for the cooling cycle in such systems of a given size or rating, to partially overcome the condition just mentioned, would raise the head pressure in the system to a point that would be dangerous and damage the system or would cause the safety devices to shut-off and open with such frequency that the efiiciency of both the cooling and heating cycles would be of little or no utility. t

Also, in some systems, where water tubes or coils are disposed within the evaporators, the water flowing in said tubes or coils freezes causing inefficient operation or a shut-down of the system until the condition is remedied or, should the tubes break or rupture, allowing the water to flow into the conduits for the refrigerant and hence damaging the system. i

I have found that superior results are obtained, in any given case, at much less cost and with a smaller evaporator by introducing only high-pressure liquid refrigerant into a non-flooded evaporator, by means of an atomizing injector or aspirator pump, which also functions as a restricter to nebulize the high-pressure liquid refrigerant,

compressor (or its equivalent) as a low pressure gas;

and any of the nebulized refrigerant that is not vaporized may be renebulized with the injected on-coming charge of high-pressure liquid refrigerant. In practice I have found that the amount of unvaporized refrigerant is relatively small during the cycle of operation and that I need to use only about 30% of the normal charge of liquid refrigerant employed in a flooded type evaporator or chiller and approximately 50% employed in the, socalled, dry expansion chillers (now most generally in use) with a much smaller evaporator for a given work-load, resulting in a more rapid response from the system and a greater work output atless cost then heretofore.

The object of the present invention, therefore, is to render evaporator units, when used as a chiller or inheat exchange systems of a heat-pump or the like, more efficient than heretofore obtainable by substantially increasing the output of a given system and, in some systems, the same result is obtainable with a liquidrefrigerant charge substantially less than that previously regarded a normal charge for such system. t

Another object of the invention is to provide an improved injector nozzle which has an accelerated pick-up of the liquid being injected or pumped thereby. A still further object of the invention is the provision of an improved type of heat exchanger which may be used either as a condenser or vaporizer, which is not susceptible of being ruptured, by freezing, with all of the attendant disadvantages known in the art as a result there of and which is relatively inexpensive to manufacture.

The objects of the present invention may be attained in a very inexpensive and practical manner by providing one or more injector (aspirator-pump) nozzles in the bottom of a non-flooded chambered evaporator and through which the liquefied refrigerant is introduced into the evaporator at substantially condenser pressure, the type of nozzle being such as to function as a restrict'or to expand and nebulize the liquid emittedtherefrom and as an aspirator-pump. The bottom of the evaporator may be (and preferably is) provided with one or more sumps into each of which an injector nozzle is operatively disposed. The nozzle is so placedor, when more than one is employed, are spaced along the said bottom--to cause the nebulized refrigerant to fill the entire vaporizer and absorb the heat .from the surfaces thereof, thus vaporizing the refrigerant very rapidly which vapor passes from the evaporator. Such small portion of nebulized liquid refrigerant, that has not been vaporized, drops to the bottom of the evaporator and flows to the sump where it is picked-up by such injector nozzle or nozzles and again entrained and nebulized thereby with the on-coming highpressure liquid refrigerant in a continuing cycle with the result that very little liquid refrigerant remains on the bottom of the vaporizer at any one time, i. e., often less than two inches in depth. It is preferred for efficient operation that the discharge end of the nozzle project, at least, slightly above the normal liquid refrigerant lever in g the evaporator.

. While this nebulization of the liquid refrigerant may be accomplished with any suitable chambered evaporator, it is preferred to employ a novel type of vaporizer consisting of a vertically disposed casing having greater height andwidth than depth, over the exterior surfaces of which flows a heat-bearing ora cooling liquid (as the case may require); and that the interior and exterior surfaces of the evaporator be provided preferably with vertically disposedfins to more quickly effect the heat exchange, the bottom wall of casing having one or more of my improved injector nozzles disposed in and supported there- .bytodirect the emitted liquid refrigerant introduced into the casing upwardly thereof, and there being a vapor take-off in the casing above said nozzles.

Other objects and advantages of the present invention will'be apparent as the detailed description of this invention proceeds.- v

In the drawings, which illustrate several adaptations of the inventions as -now-devised and used,

Figure .1 is :a schematic illustration of a system for heating water employing my invention;

Figure 2 is a schematic illustration of a system for cooling water employing my invention;

Figure .3 is a .schematic'illustration of a conventional reversible cycle :heating and cooling system which has beenmodified to incorporate the present invention at X;

Figure 4 is a schematic illustration of a reversible system for making ice or chilling water employing my invention;

Figure 5 is a longitudinal sectional view through the improved injector nozzle of my invention which is em- ,ployed to carry out the objects of the invention and illustrated as being disposed in a sump-portion of a heat exchanger; 7

Figure 6 is a section of the improved evaporator equipped with the improved injector nozzle and taken substantially on line 6-6 of Figure 4;

Figure 7 is a fragmentary transverse sectional view of the improved evaporator and'taken substantially on line 77 of Figure 6;

characters of reference refer to similar and like parts; and, as can be observed, the drawings show the improvementsof this invention in several adaptations to illus- :trate the principles'thereof.

Figures 1 and v2 illustrate very simple systems employ- .ing 7 the improvements of this invention :and each :system comprises a condenser and an evaporator, as at 11 and 12 ply, such as water for one example.

and at 11 and 12 respectively, interconnected by suitable tubing or pipe with a compressor, or its equivalent, as at 13 and 13 respectively in a conventional manner but without the interposition of the conventional expansion valve between the condenser and the evaporator, the system shown in Figure 1 being arranged to function as a heat-pump and the system shown in Figure 2 being arranged to function as a cooling or freezing unit.

While the condensers and evaporators are shown in Figures 1 and 2 as being in accordance with the improvements of this invention, it is obvious that they be of any other operable type, provided, that with respect to carrying-out the nebulization of the volatile refrigerant liquid, the evaporator should be of hollow chamber type having heat-bearing surfaces associated therewith and into which evaporator the high pressure liquefied refrigerant is discharged, through an injector nozzle X, to produce an agitated mist or spray that fills the evaporator and continuously bathes the heat-bearing surfaces of said evaporator. Since the evaporator chamber willbe under muchless pressure than the entering refrigerant, the nebulized refrigerant, :due to its expansion, is distributed throughout the evaporator chamber in a continuous movement over its interior surfaces and will more quickly and efliciently collect the heat from the said heat-bearing surfaces of the .evaporator, thus vaporizing or gasifying rapidly, and will be drawn ,as a low-pressure gas to the suction sideof the compressor or its equivalent. Should any of the nebulized refrigerant accumulate within the evaporator in liquid form, -it is entrained by the injector nozzle ,X with the oil-coming charge passing therethrough and be renebulized thereby, thus maintaining substantially all the liquid refrigerant within the evapo rator, during the cycle of operation, in a finely divided and agitated state.

With particular reference to the heat-pump shown in Fig. '1, the compressor 13, when operated, circulates the refrigerant in the system in .the direction of the arrows, drawing into it the low pressure gaseous refrigerant within the .evaporator'12 through a return ,COl'ldlllt 14 and discharging it, .asa hot high pressure gas, into anoutlet conduit .15 throughwhich it flows to the condenser 11 where said gaseous refrigerant is liquefied. This high pressure liquefied refrigerant then ,passes from: the condenser 11 through a conduit 16 to the evaporator l zinto which the liquid refrigerant is nebulized, through as aspiratoror injector :nozzle X-under the condenser pressure, to fill 'the evaporator with a mist or fine spray that impinges ,upon andbathes all the surfacesof theevaporator. This-nebulizationof the liquid refrigerant causes quick and speedy vaporization of the refrigerant, which vapor or gas is drawn by the compressor 13 thereinto through conduit 14 and is again compressed in a continuous cycle. The heat-pumpof Fig. l derives its heat from -t-he; con denser 11, which may be of the radiation or air cooled-type 20 and ll 'shown in Figures 3. an d.,4, respectively,-but is-here shown ,asa water cooled type ,wherein thecooling water is sprayed or :flows from a distributor head 17 and, by passing over the condenser .11, ,quicklys-absorbs the heat from the hot gases therein, the hot ;water being'collected in a tank or receiver .18 from which it ;is -,circulated, as .by a .purnp 19, through a heating-system, containing a radiator or radiators .or other utilitar-ian unit, generally indicated-at .20, which-dissipates the heat fromthe water, The unit .20 may be connected with .thedistributonheajd 17 to deliver cooled-waterto vthe condenser. A replenishing or make-up waterline may :be ;connec ted,.as at 2/1, to the tank 18. A distributor head 22,;similar to-the1head 17, is ;arra-nged over the evaporator :12 and connected to .a suitable source .of a :heat-bearing transfer agent a of sup- A collector tank 23 underlies the evaporator 12 to receive the -transfer agent that-has flowed over the evaporator. Thetankzs may be connected to a waste-pipe or the transfer agent therein may be recirculated to the head 22 after its temperature has been permitted to rise for its functional put poses, as by being circulated in pipes subjected to anambient air or buried in the earth for two examples.

Figure 2 discloses a system similar to that shown in Fig. 1 with the same parts rearranged to function as cooling apparatus, said parts being designated by the same reference numerals as in Fig. l but raised by the exponent a. i It will be observed that the circulating system for the heat transfer agent, which includes the parts 17*, 18 19 and 20 is arranged in association with the evaporator 12 instead of being associated with the condenser 11 as in Figure 1; and the distributing head 22* and the collector tank 23 are arranged in association with the condenser 11 instead of being associated with the evaporator 12, as in Figure l. With this arrangement, it is clear that a heat transfer agent or medium, discharged from the distributing head 17 and flowing over the evaporator 12 is cooled and delivered to the radiator or other cooling unit or device ZO -and is returned to the type shown in Figure 3 as a reversible cycle system. Such conventional reversible-cycle heating and cooling system generally comprises a compressor 13 having its intake and discharge sides connected with a conventional reverse-cycle valve 24 controlled by a suitable actuator, indicated at 25, and which actuator may, in turn, be thermostatically and/or manually controlled in any well known manner now commonly practiced. The reverse-cycle valve 24 is connected by a conduit 14 to a heat exchanger M -12 which alternately serves as a condenser and evaporator, and is here shown. as the conventional cylindrical type heat exchanger having internal water tubes 26 connected with and controlled by a conventional supply means indicated at 26*. The reverse-cycle valve 24 is also connected by a conduit 15" with a radiator 20 through which ambient air may be forced by a fan 27. In accordance with the present improvement, the bottom Wall b of the heat exchanger is provided with one or more injector nozzles X, as previously explained, and connected with the radiator 20* by conduit 16 This conduit connection 16* may have included therein, adjacent the radiator 20*, a conventional expansion valve 28 which discharges into a distributing head 29 from which the expanded refrigerant passes through tubes 29 to the radiator 20". Of course, it is understood that other types of heat exchangers may be employed instead of the radiator 20 but where an expansion valve 28 is employed the conduit 16 is provided with a bypass tube p to by-pass the expansion valve 28. The by-pass tube p is provided with a check valve v positioned to close against the flow ofthe refrigerant from the exchangerl1 ll2 to the expansion valve 28 and to open when the flow of the refrigerant is from the radiator 20* through the conduit 16 to the heat-exchanger 11 --12 The arrangement shown in Figure 3, when functioning as a heat pump system, is such that thereverse-cycle valve 24 will be actuated to allow the refrigerant to pass from the discharge side d of the compressor 13*, as a hot high pressure gas, into the pipe 15 and fiow directly to the radiator 20 it being noted that the expansion valve 23 is now closed or inactive due to the provision of the usual equalizer tube 28* and the feeler-bulb 28 connected, respectively, with the radiator 20 and the conduit 15 (which is now the hot high pressure gas line). Cooler ambient air, or returned air from the system, is drawn or forced by the fan through the radiator 20 and isheated by extracting the heat from the gases in said radiator, which now acts as a condenser and liquefies the refrigerant therein as a high-pressure liquid. The refrigerant flows, as a high. pressure condensed liquid, from the radiator 20 through the tubes 29*, distributing head 29, by-pass p and conduit 16 to the in 6 spirator or injector nozzle or nozzles X in the bottom b of the heat exchanger 11 -12 and is nebulized therein in the manner indicated by the arrows and as previously explained, forming a low pressure gas which is drawn by the suction side of the compressor 13 through the tube 14 back into the compressor in a continuous flow. The injector nozzles X, in Figure 3, may be inserted directly into the bottom b of the heat exchanger 11 -.--12 or the heat exchanger may be provided on its bottom with a plurality of sumps as shown in Figure 5.

When the valve 24 is actuated to reverse the cycle of the system to function for cooling, the hot compressed refrigerant gas, discharged from the compressor 13 at d, is delivered through the conduit 14 to the heat exchanger 11"----12 and passes over, or otherwise contacts, the tubes 26, thus liquifying the hot gas.

The liquified refrigerant drops to the bottom of the heat exchanger 1l -12 and passes, as a high pressure liquid, through the nozzles X in the bottom thereof and through the conduit 16 to the expansion valve 28 where the liquid refrigerant is discharged into a distributing head or drum 29 and, thence, through the tubes 2% into individual portions of a coil or radiator 20". Air passing through the radiator, by means of the fan 27, is chilled; and the refrigerant, absorbing the heat from the air, is converted into a low pressure gas and returns to the suction side s of the compressor 13 through the conduit 15 From the disclosure thus far it will be manifest that the nebulization of the liquid refrigerant may be accomplished in any suitable type of chambered heat exchanger by means of one or more injector nozzles X, shown in Figure 5, threaded in the bottom side of the heat exchanger, or said nozzle may be welded or soldered in position. It will be manifest also that, should the nozzles X in any given case be found too restrictive of the flow of the condensed refrigerant when passing from the heatexchanger, such as 11 --12 to the heat-exchanger 20 in Figure 3, when the system is functioning for cooling purposes, a bypass, provided with a one-way check valve, similar to by-pass 2, may be employed between the interior of the heat-exchanger li -12 and conduit 16 to permit the free flow of the high-pressure condensed refrigerant to the conduit 16 but which will close to the passage of high-pressure liquefied refrigerant from the conduit 16 to the heat-exchanger lir -12 and, thus direct such passage of the high-pressure condensed refrigerant entirely through the nozzles X at condenser pressure.

As many of such nozzles X may be employed in spaced relation along the bottom of the evaporator as may be found sufiicient to fill the same with the nebulized refrigerant, according to its size or capacity, and which, during the injecting operation, will maintain the unvaporized liquid refrigerantthat may drop to and accumulate on the bottom of the evaporator-to a point just above the injector passages 36 of the nozzle X and below its discharge orifice 35 (see Fig. 5), or to cover said orifice in some other types of injector nozzles which may be employed and which have to be primed to start the injecting operation. The exterior ends of the nozzle or nozzles X is or are connected to a supply conduit, such as 16, 16 or 16'. It is preferred that the nozzles X be disposed in sumps 38 formed in a bottom wall b of the evaporator, as shown particularly in Figure 5. Each sump is dimensioned so that the accumulated liquid will drain and collect therein and that the top of the sump is, at least, above the injector passages 36 of the injector nozzle and it is preferred that the discharge orifice 35 of the injector nozzles X project above their sumps 38 and above the normal liquid levelin the evaporator.

The injector nozzle X, shown in Figure 5, is of my improved construction which gives extremely quick acceleration and force in injecting or entraining the liquid refrigerant in the bottom of the heat-exchanger.

30. projecting from one end of a threaded boss 31 havinga. wrench-head 32 on its other end. The jet nozzle 30 is conical externally and internally terminating in an axiallydisposed discharge opening 30 and commumcating at its base with a passage 33 in said boss and-wrenchhead. 32. The passage 33 is internally threaded to receive the threaded end of the conduit tube, suchas 16, 16 or 16' Surrounding the impeller jet nozzle 30 is a sleeve 34 which has its inner end suitably secured to the boss 31 in any suitable manner, soldering being shown. The interior of the sleeve 34 is formed to provide a Venturi throat 35 at a distance beyond the discharge opening. 30 of the impeller jet, this throat being preferably formed by having its inner portion 35 conical and spaced from the exterior conical surface of the impeller jet 30 and converging to the throat 35 and by having its outer portion 35 formed with a conical surface diverging from said throat 35 to provide the discharge orifice 35 The crosssectional area of the throat 35' should be in the order of about twice that of the crosssectional area ofthe impeller jet opening 30 Injector passages 36 are provided in the sleeve 34 to communicate the exterior of the sleeve with the interior thereof and are positioned at a point in the sleeve between its inner end and the impeller-jet opening 30*, these passages being preferably circumferentially about the sleeve. The injector passages 36 may be of any configuration or dimension, but it is preferred that they compose a circumferential series of passages of about ,4 inchin diameter to form strainer screen to exclude sediment or any foreign matter larger than the throat 35 from passing into the injector nozzle, the total opening area of the passages 36 being in excess of the space area bet-ween the inner surface of the sleeve 34 and the jet nozzle 30 at the point where they oppose, and, preferably, not less than 3:1 with respect to the narrowest cross-sectional area of the throat 35, thus providing adequate admission of the liquid to be injected or pumped. The nozzles X may be periodically cleaned by merely unscrewing them; however, in practice it has been found thatthis screen is an over-precaution and seldom needs to be cleaned.

The injecting action of the injector nozzle X is m'aterially enhanced by the provision of an interceptor bar or bafile 37 extending transversely across the passage of the impeller-jet 30 at a point substantially inwardly of and aligned athwart its orifice 30 as shown in Figure '5' of the drawings. This transverse baflle 37 consists of-a bar or rod having its ends swedged or soldered in suitable openings drilled in the nozzle wall. The surface of the bar opposing the flow of the impeller liquid through the jet 30 is flat, as shown at 37 in Fig. 5, and is of a width to obstruct about one-third of the area of the passage in the jet nozzle 30 at the point where the bar is posi-- tioned. The back surface of the bar 37 may be rounded, as shown.

that by the employment of the bar 37 with the flat surface 37*, the injecting action of the nozzle X has been greatly increased by the propelling action of the impelling refrigerant emitted from the impeller jet30 and creates such a suction orimpelling-actionon the fluid, being injected through the injector-passages 36, that the injection action can be started without priming or the liquid covering the top of the injector-nozzle so long as the liquid merely covers the injector passages 36. In the use of my injector nozzle X constructed as above, with the jet discharge opening 30 of inch in diameter and and l0; are constructed; in accordance with my present improvement; to etfecvquick heat 'exchange'in connec- From practical operation, it has-been found tion 'with'a nebulized volatile refrigerant and to preventdamage thereto, due to freezing of the heat-transfer agent or medium and/or its seepage into the system with the refrigerant clue to rupture caused by said freezing. This improved heat-exchanger may serve eitherv as an evapo-' rator or-as a condenser, as shown; but, when used as a condenser, it need not'be equipped with the nozzle X except in a reversible system where the heat-exchanger acts alternately as condenser or an evaporator accord ing to the direction of cycle of operation, as is well understood in the art.

The detailed construction. of the heat-

exchangers

11, 11*, 12 and 12 is more. particularly shown in Figs. 6 and 7; and, in addition to its above mentioned advantages, also may be employed as an ice-maker, as will be later described. These heat-exchangers comprise a vertically' positioned and generally rectangular shaped casing C having a height and width greater than its thickness-or depth. The casing is preferably-constructed from sheet metal with spaced and opposed sidewalls s, end wall e, bottom wall b and a top wall t. The dimensions of the casing C may be that designed for a required or given capacity. When the casing .C is to be used as a heat-exchanger with a liquid heat-transfer agent or medium, such for instance as water; its side walls s converge upwardly, as shown, so that the heat-transfer agent may flow downwardly and exteriorly of'the. casing. C from an overlying source of supply. If the side walls s converge upwardly, as shown in Figs. 1, 2, 4, 6 and 7, as preferably for use withra liquid transfer medium, the top'wall t may be omitted and the top edges of the side walls s may meet. When employed asan evaporator, the bottom wall b of the casingC is provided with one or moresurnps 38 in which a nozzle X is disposed, as explainedabove.

The exterior, and preferably the interior, surfaces of the casing C are provided with finsf to accelerate the heat exchange. These fins, preferably formedof elongated strips of sheet metal, substantiallyright-angular in cross-section, are arranged vertically on said surfaces of the side walls s and end walls e extending from the top to the bottom thereof and lying in close relation with one of their angular portions fiat against said walls and secured thereof by welding or soldering, thus reinforcingsaid walls.

In Figures 8 and 9 isshown a further extensionof my improved evaporator C which may be employed in any system having a pressure differential from a high to a low side and does not require internal circulating tubes therein, but may be submerged in a heat medium from which heat may be extracted by conductivity or radiagive rigidity to the same, if necessary. One or more injector nozzles X may extend into the bottom of the chamber C through the bottom wall 43 to direct its spray upwardly into the chamber C and connected (as described in connection with Figs. 1, land 3) to a high pressure conduit'16, 16 or 16, whereby the liquefied refrigerant will be nebulized by theinjector nozzles X,.

as previously explained, until-it has absorbed sufficient heat from the side walls of the chamber. C to gasify and 1 discharge from the chamber C through conduit 14, as

a low pressure gas.- The charge of refrigerant required, with the heat exchanger C, may be only enough to keep thepassages 36 in the injector nozzles -X covered innormal operation, as indicated, thereby usingrless refrigerant and functioning more effectively. Of 'course, fins flshown in Figs. 6 and 7, may be arranged within, as well as as panels in the walls of buildings and which does not require the use of expensive cooling coils or of a isocalled honey-comb construction. This cooling unit, like the heat-exchanger shown in Figs. 6, 7, 8 and 9, comprising a rather narrow vertical disposed elongated chamber C" having side walls 50, end walls 51, a top wall 52 and a bottom wall 53, all of heat conducting material, and the side walls may be connected by stayrods 54 to give strength and rigidity to the structure, if

necessary. Baffles 55 are thermally connected to the walls of and suitably arranged in said chamber C to deflect and transfer, one to the other, liquefied refrigerant emitted into the top of said chamber and to direct it downwardly to the bottom of said chamber. One or more injector nozzles X may extend into the chamber C" through the bottom wall 53 and connected to conduit 16 supplying a high pressure liquified refrigerant thereto. Connected to each injector nozzle X is a vertical pipe 57 extending to the top of the chamber C? and provided with a downwardly direct discharge end 57, whereby the nebulized refrigerant showers downwardly of said chamber and is intercepted by said baflies 55, thus absorbing the heat from the walls of said chamber. Any refrigerant that is vaporized by this action passes as low pressure gas back to the compressor, or the like, through pipes 14 as shown in Figs. 1 and 2; but such of the refrigerant which is not vaporized falls into the bottom of the chamber C" and is again picked-up (as previously explained) by injection through passages 36 in said injectornozzles X and redischarged at 57 until it has absorbed suflicient heat to gasify and discharge from the chamber C" through low pressure conduit 14. If desired, the exterior surfaces of the side walls 50 may be provided with fins 7 as shown in Figs. 6 and 7.

Further utilization of the improvements of my invention is shown in Figures 4 and 6, wherein there is disclosed a novel system for making ice and/or chilling water for commercial purposes.

sheet toa permissible or desired degree, anyexcess water flowing into thetank 23 for recirculation. When the desired thickness of ice has formed on the walls of the evaporator 12, the reverse-cycle valve 24 may be manu ally actuated, or may be automatically actuated by a control means 25, shown in Fig. 3 or other equivalent means, which in turn is preferably actuated by a timing device or thermostat not shown, to cause the hot refrigerant gas, from the compressor 13, to flow directly into the evaporator 12 by means of pipe 14, where the heat of said gas causes the ice adhering to the surfaces of the evaporator to drop therefrom into a bin 60. The bottom of the bin may have a conveyor belt 61 therein to move the ice therefrom. After a predetermined time lapse, the control means is again actuated, either by said timing means or by a thermostat 62, to operate reversecycle valve 24 to reverse the operation of the system to repeat its cooling or freezing operation, just described, until the machine is shut-down or stopped. Of course, it is understood from the foregoing description that, after the hot refrigerant gas enters the evaporator 12 from pipe 14 during the heating cycle, it liquifies and returns to the condenser 11 through pipe 16 where it vaporizes and passes to the suction side of the compressor 13. The fins f, on the exterior surface of the evaporator 12, will cause the ice to form much more rapidly and in long and narrow strips that are easily handled and may be easily broken to desired lengths or crushed.

The apparatus shown and described in connection with Fig. 4 may also be economically employed for chilling water for commercial or industrial purposes and, to this This novel system is preferably of the reversible cycle type similar to that shown in Figure 3 and may comprise a compressor or equivalent 13, a reverse-cycle valve 24, a condenser 11, an evaporator l2all conveniently arranged and interconnected in the usual manner. The condenser 11 may be of any desired or convenient type, but is here shown as an air cooled type. The evaporator 12 is of the type, hereinbefore described in connection with Figs. 1, 2, 6 and7, comprising a, vertically disposed hollow casing having bottom wall b, upwardly converging side wall s and relatively narrower end walls e, the bottom b having one or more sumps 38 therein, in which are mounted injector nozzles X preferably of my improved type above described. A water distributor head 22 is arranged and supported over the apex of the side-walls s to direct a water spray downwardly onto the declining surfaces thereof. The distributor head 22 is supplied from a suitable source, which may be an open tank 23 disposed under the evaporator 12 to catch water that may flow therefrom. The tank 23 may be supplied by a feedpipe 21 controlled by a water-level means 39; and the water from the tank 23 maybe pumped therefrom to said distributor head 22, by a pump 19. With this arrangement, water discharged from the distributor head 22 flows over the exterior surfaces of the side walls s of the evaporator 12 and is caused to freeze thereon, during the nebulization therein of the high pressure liquefied refrigerant flowing thereto through pipe 16 from the condenser 11, which, in turn, receives. hot refrigerant gas through pipe 15 from the discharge side of the compressor 13. The gradual freezing of said water flowing from the head 22 will increase the thickness of the ice end, the cold water flowing down the side-walls s of the evaporator may be collected in the tank 23 and the distributor head may be connected directly to the supply pipe 21, the pump 19 being employed to discharge the cold water to a service system, and, in such case, the water-level control valve 39 may not be used.

Having thus described my invention and the several manners in which the same may be performed, it will be seen that the objects thereof are attained by the con structions therein disclosed; but, since the said constructions are susceptible to modifications and variations (some of which being stated and others being obvious after stating my invention), it is to be understood that the invention herein described is to be limited only by the scope of the appended claims.

Letters Patent is:

1. As a method of more effectually utilizing a volatile liquified refrigerant in a circulating heat-exchange system having a condenser-means and an enclosed evaporator-chamber with heat-transfer surfaces; the steps of continuously passing to said chamber only the liquified refrigerant, coming from said condenser means, while under pressure from the condenser and discharging the same into said chamber, under said pressure, in a nebulized stated causing all but a small percentage of said discharged refrigerant to flash and causing .a non-flooded condition of said chamber, during the operation of the system; said discharge of the refrigerant into said chamber inspirating therewith any unvaporized refrigerant that has been previously discharged and collects in said cham her, as a liquid body, to renebulize the same; and drawing the vaporized or gasified refrigerant from said chamber intothe system.

2. As a method of more effectually utilizing a volatile liquified refrigerant in a circulatingheat-exchange system having a condenser means and an enclosed evaporatorchamber with heat-transfer surfaces; the steps of continuously injecting in a nebulized state all of the condensed liquified refrigerant, coming from the condenser means, directly into the non-flooded evaporator chamber and under condenser pressure, during the operation of the system, causing rapid gasification of said refrigerant; said injecting of said refrigerant in said chamber inspirating therewith only, thenebuli zed. refrigerant that collects in the chambenas a .liquid body, to renebulize the same; anddrawingtth e vaporized or gasified refrigerant from said chamber into thesystem. 7

32 In an apparatus employing a circulating refrigerant andmwhich. includes a system having a condenser means for converting-the refrigerant, in its gaseous phase, to a high pressure liquid and. a heat-exchanger to-gasify said high-pressurealiquid; the improvement being-that saidheat-exchanger has an enclosed chamber therein connected in-said system, ,one orv more atomizing injector nozzles located in saidchamber and connected-directly to-the condenser insaid system to have allof the refrigerant from the condenser pass therethrough in its liquid phase-and substantially undercondenser pressure, during the operation-of said-system, whereby said liquefied refrigerant acts as .a high-pressure liquid impellant pumping medium for said injector nozzle or nozzles, which latter ncbulizes the liquefied refrigerant passing therethrough; thearrangement being such that-the emitted nebulized liquid refrigerant impinges upon and contacts the interior surfaces within said -chamber,.efiecting quick gasificationof-the refrigerant without floodingsaid chamber with a liquid body, and inspirates any ungasified low-pressure refrigerant ,.-thatiaccumulates in said chamber, with the on-comingi-high-pressure liquefied impellant refrigerant and re-nebulize the same, whereby said interior surfaces ofsaidheat-exchanger maybe repeated and continuously bathed-bythenebulized liquefied refrigerant, during op eration ofthe-system, until gasified and drawn from said chamber, asalow pressure gas, to beagain converted to a-high'pressure gas.-

4. Anevaporator for-a circulating volatile refrigerant systemhaving a condenser means and a compressor means, said evaporator comprisingta hollow body member forming a chamber having. an outlet removed upwardly from thebottom-thereof, an atomizing injector nozzle mounted in: the bottom of said chamber for connection in a circulatingsystem-toreceive liquefied refrigerant therefrom at substantially condenserpressure-and to function as a restrictor and positioned to. direct its emitted liquefied re= frigerant upwardly to impingeupon the interior surfaces of said-chamber in a finely dividedstateand pass through saidoutlet asalow pressuregas, saidnozzle having an inspirator passage therein positioned to cause any ungasi fied refrigerant accumulating on the bottom of said chamber to be entrained with the highpressure liquefied refrigerant, beingintroduced into said chamber, so as to be renebulized' therewith, whereby said chamber is not flooded with a liquid body-of said refrigerant and the surfaces of said chamber are continuously bathed-withnebulizedliquid refrigerant, while the system is-in operation,-until gasified and drawn from'said chamber.

5. The subject matter ofclaim 4 wherein said chamber has a sump in the'bottom thereof into which liquid refrigerant on the bottom of said chamber flows, saidnozzle being positioned in said sump and having theinspirator passage thereinwithinand communicating with the-sump, the discharge orificeof said nozzles projecting above said sump and above the normal level ofanyac cumulated liquefied refrigerant in said chamber.

6. The subject-matter of claim 4 wherein said heat exchanger is a-vertica'lly disposed enclosed hollowcasing of heat conducting material of greater height and width than cooling" system employing a volatile refrigerant; saidevaporator comprising a closed panel member of heat mally connected tosaid walls of said chamber to deflecta'nd pass said refrigerant one to the other in its downward passage in said chamber, any liquefied refrigerant accumulatingin thebottom 'of said chamber may be repeatedly inspirated by. said nozzleor nozzles with the impelling' medium upwardly in said tube and discharged therefrom untilgasified, said chamber having a gas outlet therein adapted to beconnected inthe cooling system.

9.' Incombination with a reversible heat exchange system employinga volatile refrigerant, of a heat exchanger alternately actingas a-condenser and as an evaporator upon reversed" cycles of said system, said heat exchanger being. .a vertically disposed wall-enclosed chamber having two opposed sides converging upwardly from its bottom,- a water spray device arranged to direct its spray onto the exterior surfaces of I said inclined sides of said walls,

atomizing injector nozzle means located in the bottom of said chamber andiconnected in said system with the high pressure'liquefied refrigerant and positioned to direct the nebulized refrigerant upwardly into said chamber to impinge the walls thereof, saidnozzles having an inspirator passage therein adapted tobe surrounded by liquefied refriger'ant accumulatin'gon thebottom of said chamber to re'atomize the same withthe oncoming pressure charge of the liquefied refrigerant, said chamber having an outlettherein removed upwardly from said nozzles and connectedin said system to draw gasified refrigerant therefrom as a low pressure; gas, whereby ice may be formed on said exterior inclined surfacesof said heat-exchanger andmaybe released therefrom uponreversing the cycle ofthe system allowing said ice to move downwardly off said surfaces.

10L The subject matter of claim 9 wherein there is a collector to receive excess water flowing from said inclined surfaces of the heat exchanger and connected with the water supply to said spray device, and means for receiving and collecting the ice dropping from said heat exchanger. v

11'. A vaporizer for a circulating volatile refrigerant comprising :a shell-like heat-exchanger in the form of a walled chamber of heat conducting material and devoid of fliiid circulating tubes therein for a separate heat-' exchange medium and having an inlet and an outlet for said refrigerantto pass thereinto and therefrom, respectively', atomizing injector-nozzle means located in the bottom portion of said heat-exchanger to be surrounded by any liquified refrigerant in the bottom of said heat exchanger for aspirating said liquified refrigerant and-connected in acirculating system at the inlet of said heatexchanger',- said nozzle means being positioned to direct its emitted spray to impinge upon and contact the interior surfaces-within said heat-exchanger, whereby said interior surfaces ofsaid heat-exchanger may be repeatedly and continuously bathed by atomized refrigerant emitted from said nozzle means while the system is in operation until gasified or vaporized.

References Cited'in thefileof this patent UNITED STATES PATENTS 2,117,506 Reinhardt May 17,

2, 23,921 Y Phillips- July 5, 1938 2,132,932 Boileau Oct; 11, 1938 Brizzolara' May 23, 1939 Anderson et al. Oct. 6, 1942" 2,381,589 Hayes Aug. 7, 1945