US2262657A - Refrigeration - Google Patents

Description

A. D. SIEDLE REFRIGERATION Nov. l l, 1941.

2 Shee'rts-Sheet 1 Filed Oct. 10, 1938 INVENTOR Arnold D., J'edle ATTORNEY Nov. ll, 1941. I A. D. SIEDLE 2',262,6 57

` REFRIGERATION Filed oc. o, 1938 2 Sheets-Sheet 2 I 3 I INVENTOR ,l Arnold D. ''edle /6' Patented Nov. 11, 1941 Arnold D. Siedle, Carlton, Ohio, asignor to The u Hoover Company, 'North cto, Ohio, a corporation of Ohio Application October o, 1938, serial No. 234.143

'o cams. (Ci. 62-1195) Referring now to the drawings in detail and I This invention relates to the art oi reirigeration and particularly to a novel absorption refrigerating system which is constructed and arranged automatically to freeze blocks of ice in a body of water to a predeterminedsize and then to discontinue the production of refrigeration for ice freezing purposes for a period of time sufiicient to allow previously ormed ice blocks 'to float to the surface of the water from which they have been ormed.

Previous reirigerating systems have been proposed in which the production of ice and the melting period thereof are regulated by various forms of thermostatic control mechanisms which may be within or without the reirigerating system. However, all such previous constructions necessitate'the use of control means which add considerably to the cost and Complexity of the apparatus.

Accordingly, it is a principal 'object of the pres-' ent invention to provide a refrigerating system of the above referred to character in which the production and melting periods of the ice are automatically regulated without the intervention of any speciah form of control means within or 'without the system and without necessitating 'cooled absorber A, a liquid heat exchanger L. a

as burner G for heating the boiler B, a solenoid the provision of any moving parts'in order to o efiect the desired control of the apparatus.

More specifically, it is an object of this invention to provide a reirigerating system of the character above referred to which will automatically store refrigerant liquid enroute from the condenser to the evaporator ior a period of time sufllcient to permit previously formed ice blocks to inelt free of the walls oi the water container and to discharge such accumulated liquid periodically into the evaporating zone in order to produlce another crop of ice biocks. v

' It is a further object oi one form of the invention so to arrange the rerrigerant accumulating 40 means that the same operates to interrupt the flow of pressure' equalizing medium through the evaporator of the reirigerating system to accelerate the melting of previously tormedice blocks.

Other andmore specific objects ot the invention will become apparent as the description proceeds when taken in connection with the accompanying drawings, in which: A

Figure 1 is a diagrammatic representation oi a reirigerating system embodying' the present oo invention. I

Figure 2 is a transverse sectional view of the I evaporator structure of the present invention.

Figura 3 is a fragmentary diagrammatic. illustration of a modified form oi theinvention.

type embodying avboiler B, an analyzer D, a rectier R a tubular air-cooled condenser C,` an evaporator E, a gas heat exchanger H, a tubular airliquid circuits constitutinga complete reiriger ating system to which reference will be made in' more detail hereinafter.

The above described refrigerating system` will be charged with a suitable refrigerant, such as ammonia, a. suitable absorbent, such as water,

and a suitable inert pressure equalizing medium preferably a dense inert gas such as nitrogen.

The application of heat to the boiler B generates refrigerant vapor from the strong solution therein contained. The refrigerant vapor so liberated passes upwardly through the analyzer D in 'counterfiow relationship to strong solution fiowing downwardly'ther'ethrough. I'urther refrigerant vapor is generated in the analyzer from the strong solution by the heat 'of condensation of absorption solution vapor which is generated in the boiler. The refrigerant vapor iormed in the'analyzer is conveyed therefrom to the upper portion of the condenser C by means oi a conduit ll which includes the air-cooled rectifier R. The rectifier R causes condensation of any vapor of absorption solution which may pass through 'the analyzer. The refrigerant vapor supplied to the condenser is liqueiied therein by heat exchange relationship with the .surrounding air and is discharged in liquid phase through a conduit II into a syphon chamber !3. A small vent conduit II is connected between the chamber |3 and the outer .pass of the gas heat exchanger H.

The liquid collecting in the syphon chamber 13 is peroidically discharged the'eirom, in a man ner to be described in detail her'einaiter, through a syphon conduit IS into the bottom portion o! the evaporator E. The'exact construction ofthe evaporator E will be described in detail hereinafte'r: tor the present it is suflicient to note that the liquidreirigerant discharged from the con'- duit I! into the evaporator evaporates into a proiormed in the evaporator is conveyed therefrom through 'the conduit I'I into the inner path of These elements are suitably connected the gas heat exchangerH from which it is 'conveyed through the conduit s into thebottom portion of the absorber A.

The rich pressure equalizing medium refrigerant vapor mixture flows upwardly through the absorber A in counterflow relationship to Weak solution fiowing downwardly therethrough. The

refrigerant vapor content of the mixture is absorbed in the solution and the resulting lean gas is conveyed from the upper portion of the absorber into the suction inlet of the circulating fan F by a conduit !9. T'he lean gas is placed under 4 pressure in' the'fan F and is discharged therefrom into the outer path of the gas heat exchanger H through a conduit 22. The lean gas is then conveyed from the' outer path of the gas heat exchanger H to the bottom portion of the evaporator E through 'a conduit 23.

The lean solution frmed in the boiler by'the generation of refrigerant vapor is conveyed therefrom to the upper portion of the absorber A through a conduit 24, the inner path of the liquid heat 'exchanger L, and a conduit 25. It is apparent that theupper endof the absorber is at an elevation above the normal liquid level preand the burner Gr is under the complete control -of a single box-temperature responsive thermo'- 1. v A heat conducting plate 42 separates the coil 40 from the storage portion of the compartment 41. The compartment 4! will be provided with any suitable form of insulated door structure not shown. The free end of the coil structure 40 communicates with a riser conduit 43 which joins v a horizontally positioned evaporator ice-freezing vailing in the boileranalyzer system wherefore some means must be provided in order to elevate the lean solution into the absorber. For this purpose, a small gas bleed conduit 26 is connected between the lean gas discharge conduit 22 of the circulating fan F and the conduit 25 below the liquid level normally prevailing. therein whereby the lean solution i's elevated into the absorber by gas lift action. The lean solution I flows downwardly through the absorber by gravity' in counterfiow relationship to the rich pressure equalizing medium' refrigerant vapor mixture in the manner described heretofore. The

refrigerant vapor content of the mixture is absorbed in the absorption solution and the heat of absorption is rejectd to the surrounding air by fins mounted on the exterior wall of the ab sorber vessel. The strong solution formed in the absorber is conveyed from the bottom portion thereof to the upper'portion of the analyzer D by means of the-conduit 28, the'outer path of the liquid heat exchanger` L, and the conduit 23.

The burner G is suppliedwith gas through a gas conduit 30 which is govemed by the solenoid valve S. The burner G is provided with any suitable form of safety cut-off mechanism which will operate automatically to discontinue the supply' of gas thereto whenever there is complete failure of flame at the burner. A small by-pass 3! is provided around the solenoid valve S in order to' maintain a small pilot origniting flame onthe burner G.

Electrical energy is supplied to the apparatus from a. suitable source ofvsupply represented by the wires 33 and 34. The wire 33 connects directly to one terminal of a thermostatic control mechanism, 35 which will be mounted to beresponsive to the temperature of the air within the refrigeratng storage compartment; Any suitable or desired form of thermostatic switch may be provided, but preferably the mechanism will include a'manually operable temperature adjusting mechanism. The other terminal of the thermostatic control 35 is connecteddirectly to the solenoid S by means of a wire 35. -The motor isconduit 44. The conduit 44 terminates in a riser conduit 45 which joins a second ice-freezing conduit 46 positioned directly above the conduit 44. The conduit 46 communicates with a horizontally positioned ice-freezing conduit 41 through a rear cross-connecting conduit 40. The conduit 41 is horlzontally positioned in -spaced relationship with the conduit 46. The conduit 41 communicates with a riser conduit 49 which is parallel to the riser 45 and opens into a horizontally'positioned ice-freezing evaporator conduit 50. The

ice-freezing evaporatorconduit 50 is positioned in the same plane with and parallel 'to the icefreezing evaporator conduit- 44. i The ice-freezing evaporator conduit 50 is connected directly to the ,rich gas discharge conduit l1. A liquid drain conduit 52 is connected between the gas outlet portion of the conduit 50 and the gas inlet portion of the conduit 40 after extending downwardly below the plane of the conduit 40 to form a liquid gas seal.. .V i

A drain conduit 55 opens into the top portion of the' gas discharge end of the conduit 40 and connects to 'the rich solution conduit 29.

Each of the ice-freezing conduits 44, 46, 41

r and 50 is provided with a 'plurality of spaced heat connected to the wire 36 by means ofawire 31.

The other line wire 34 connects directly to the motor M and is connected to the solenoid valve i S by means of a wire 30. Asa result of this arrangement the energization of the motor M conducting pads 56 which are adapted to receive the slightly tapered side walls 51 of a water tank 58-shown in dotted lines in Figure 1. The water tank 58 rests upon the top wall of the insulated compartment 4flwith the side walls 51 thereof in firm thermal contact with the freezing pads 55. The arrangement of the tank and evaporator is such that the tank may be removed from the evaporator by vsliding it forwardly or by lifting it upwardly as may be desired.

-The operation of this form of the invention u is as fo'llows: Assuming that the apparatus has not been Operating the temperature' within the ref'igerating chamber will have risen to cause the thermostat 35 to energize the circulating motor M and the solenoid valve S to vsupply gas to the burner G. Under these conditions, re-

frigerant vapor will be generated and will ultimately find its way through the conduit |2 into the syphon chamber I 3. `The 'liquid refrigerant will accumulate in the syphon chamber |3 until it shall have reached a depth sufiicient to cha'ge the syphon conduit l5. Once the syphon conduit |5 is charged it will syphon out all refrigerant previously collected in the chamber |3 and all' refrigerant discharged thereinto until the liquid level within the chamber I 3 haslowered sufliciently to break the seal on the syphon. The capacity of the conduit !5 is larger than the capacity o'f the conduit |2 in order that the conduit !5 may uitimately empty the chamber |3 to break the seal and to discontinue the discharge of refrigerant therethrough. The vent conduit |4 serves to purge the condenser C of incondensible products and to equalize the pressure in the conduit 23 and the chamber !3.

The liquid refrigerant discharged through the conduit l5 meets a propelled stream of gas which is circulated through the evaporator by the circulating fan F. The liquid refrigerant so dis-V sure that the ice blocks prevlously formed will have melted free otithe interier walls of the tank. Therefore, when the discharge conduit |5 again becomes operative a fresh crop ot ice' blocks will u v be formed in the water tank.

This operation will continue for as long as the control mechanism 35 maintains the energization of the solenold valve S and the circulating'motor M. The 'air within the refrigerating comparte ment is cooled by contact with the exposed walls of the tank 58 which are extensive. The temperature of the walls of the tank 58 'is normally maintained above the freezing point of water wherefore there is no frost formation thereon 'and the air within the reirigerating compartment is not unduly dried. Any frost which forms on the various exposed ice freezing evaporator conduits 'during the refrigerating cycle will melt drain 52 is sealed the velocity of flow of the gas v through the evaporator is increased and the remaining liquid discharged by the syphon |5 is propelled through the evaporator by the gas stream as it is evaporating to produce refrigeration. Any liquid refrigerant not evaporated in the conduit 40 is then propelled by the gas stream through the conduits 43, 44, 45, 46, 41, 48. 49 and 50; respectively, in all of which conduits evaporation occurs to produce refrigeration.

The liquid is propelled by the frictional drag exerted thereon by a relatively high velocity stream of nitrogen which drags or sweeps the liquid through the evaporator as it is evaporating. The broad invention of propelling the liquid refrigerant by the .inert gas is disclosed and claimed in the co-pending application of Curtis C. Coons and William H. Kitto, Serial No. 386395, filed April 2nd, 1941. A

During initial operation of the system a very 'large portion of the refrigerant will evaporate in the conduit 40 thereby rapidly lowering the temperature within the compartment 4I. Once the temperature oi' the compartment 4| is lowered relatively little refrigeration is required therefor even when 'foodstufis or frozen desserts and the like are placed in the chamber H because there is substantially no heat loss through the wall thereof. Any liquid refrigerant which may not evaporate prior to the time at which it reaches the conduit l'l i's discharged through the conduit 52 into the evaporator coil '40 to be 're-circulated through the evaporator.

4 The above described operation of the apparatus will continue until such time as the conduit l5 shall have emptied the chamber l'sumciently to break the syphon seal, whereupon liquid re-.

frigerant will again begin to collect in the ham ber !3. The liquid refrigeraut in the evaporator is continuously recirculated therethrough until it is' substantially entirely evporated. The pads 55 are so proportioned that the quantity of liquid discharged through the -condult l5 will be sufllcient to freeze ice blocks of a predetermined'size on the interior side' walls of `the tank 50 wherever such walls are in directthermai contact with' one of the freezing pads. 'After the syphon seal is broken and the residual liquidrefrigerant in free. thereof during the ice melting cycle and .may be collected in any suitable tray or may simply be allowed to evaporate into the air within the refrige'rating compartment.

The recirculating conduit 52 need not be e charged after the inital operation of the system as the refrigerant therein contained will not evaporate appreciably into the inert gas after the syphon conduit has become inoperative.

The above described refrigerating system liquefles and discharges liquid refrigerant into the syphon chamber substantially continuously and the refrigerant liquid alternately collects in that I chamber and is then discharged therefrom .at a relatively rapid rate into the evaporation zone. By the provision of the recirculatingxdrain 52 the rather large amount of liquid refrigerant discharging throughthe conduit |5 is not wasted. It is simply continuously recirculatedthrough the evaporator until it has evaporated to produce refrigeration'. The freezing period of the apparatus extends over into what would normallybe the melting period during which liquid refrigerant is again collected in the chamber !3 to recharge the syphon conduit `|5. This ls ,a desirable feature for the reason that the freezing period for 4 the ice blocks will normally'be longer than the period required for the same to melt free of ,the

inner wall of the water tank 58.

Referring now to Figure 3, there is disclosed a .modified form of the'invention. This form of the invention is designed and intended to be' utilized with the refrigerating system disclosed in Figure 1, therefore only such portions of' the apparatus has been illustrated as will be necessary to delineate the difference between the con- I struction illustrated in Figures 1 and 3. certain portions ofthe apparatus disclosed in Flgure 3 are identical with parts illustrated in' Figure 1 and are therefore given the same reference characters primed.

In this form of the invention the rich gas discharges from the conduit 60, which' communicates with the ice-freezin'g evaporator conduit '50', into the top portion oi' a syphon chamber SI. A rich gas discharge conduit 62 connects the inner passage of the gas heat exchanger HQ u with the lower portion of the syphon' discharg'e chamber GL' The conduit 02 extends upwardly the evaporator has evaporated,` reirigeration will 5 to charge the syphon conduit !5 is 'ample to in -2 except in the following Duringthe substantially the same as the operation oi'the in a loop an appreciable distance above its point of connection with the chamber GL The syphon discharge. conduit l5i connects to the conduit 40' as before. x

The operation of this 'form of the invention form of the invention disclosed in-Flgures 1 and ice melting cycle of the apparatus the liquid 'efrigerant discharging through the conduit |2' will accumulate in the lower portion ot the chamber SI and will eventually seal the inlet to the conduit 62, thereby stopping the inert gas flow through the evaporator. This stoppage of inert gas flow through the evaporator" will accelerate ice melting and will positively insure that there is no production of refrigeration due to residual liquid in the evaporator during normal ice melting' periods.

In order that this apparatus may come; into operation reasonably quickly after the syphon becomes operative, the syphon in this case is of larger capacity than the syphon described in connection with Figure 1 in orderthat it may lower the liquid level in the syphon chamber to permit inert gas flow through the evaporator. Also the syphon |5,' is provided with a U-shaped portion extending downwardly below its point of connection to the conduit 40' similar to the U- shaped traps in the conduits 52 and 52'. This is necessary in order to prevent by-passing of the inert gas from the relatively high pressure conduit 40' into the relatively low pressure chamber SI. The quantity of liquid in the evaporator is too large to be evaporated on one cycle of operation thereof, wherefore there is a continuous circulation of liquid refrigerant through the evaporator and the recirculating drain 52'. The apparatus is so proportion'edthat refrigeration will be produced by recirculated liquid refrigcrrefrigerant into the evaporator, and means for collecting liquid refrigerant which has traversed I said evaporator under theimpetus of the inrt gas and for returning such liquid refrige'ant to said evaporator for recirculation therethrough. e

2. Absorption refrigerating apparatus comp'rising an evaporator, liquid refrigerant producing means; means for intermittently discharging a predetermined quantity of liquid refrigerant into said evaporator comprising a container, means for conveying liquid refrigerant from said producing means .to said container, and a syphon connecting said container and said evaporator arranged ,to'become operative when the liquid level in said container reaches a predetermined level and then to drain said container, means tor circulating an inert gas through said evaporator with suflicient velocity and pressure to circulate liquid refrigerant through said evaporator, and

ant substantiallyup to the time the collecting I liquid seals the inlet'to the inert gas conduit 62. The duration oi thisperiod will be suflicient to -means, means for intermittently' discharging a v form ice blocks of 'the desired predeternined size.

The present invention provides a simple highly i efllcient absorption refrigerating system constructed and arranged alternately -to produce ice within a large body of water and then to permit previously formed ice to melt free ot the containing walls of the water tank whereby the various ice blocks may float to the surface of the water to be ladled threfrom as needed. {This is accompiished without the intervention of control means of any character whatsoeverexcepting `only of course the accumulating syphon ta'nk which is absolutely independent of any thermally means for collecting liquid refrigerant which has traversed said evaporator and tor retuming such liquid refrigerant to said evaporator' for recirculation therethrough. e

. 3. Absorption refrigerating apparatus comprising' 'an evaporator, liquid refrigerant producing predetermined quantity of liquid refrigerant into said evaporator comprising a, container, means for conveying liquid refrigerant from said producing means to said container, and a syphon connecting'said container and said evaporator arranged -to become operative when' the liquid level in said container reaches a predetermined level and then to drain said container, the dis-- charge rate of said syphon being greater than' the rate at which liquid is supplied to said container, and means for circulating an inert gas through said evaporator. v

4-. Absorption rei'rigerating ap'paratus comprising an evaporaton\ liquid refrigerant prod'u'cing responsive mechanism, contains no moving parts,- i

and is fully automatic in operation.

The refrigerating efl'ect may be discontinued as desired either by eliminating 'the supply of liquid' refrig'erant to: the evaporating zone or by utilizing the collection ot liquid refrigerant to block.

inert gas flow through the evaporator.

'invention regulates the production of ice automatically in; relation to the demand therefor as follows; During periods of warm weather the rate of heat'loss through the box increases which causes the box temperature responsive the'rmostat to cycle more frequently .with .consequent increase in the rate of production of'ice; however, it is during periods oi warm weather that the demand' for ice is greatest; therefore the de-.

mand in production of ice isautonatically geared to the demand therefor by the ambient temperature. p a While the invention has been illustrated and described in detail it is not to be limited thereto as various changes may be made in the construction, arrangement and proportion of parts without departing from' the spirit of the invention or the scope of the appended claims. i I claim: I

1. Reirigerating apparatus 'comprising an means, means for intermittently discharging'a predetermined quantity otliquid reirigerant into said evaporator comprising a container, means for conveying liquid refrigerant from said producing means to said container. and a syphon connecting said container and said evaporator arranged to become operative when theliquid level in said container reaches a predetermined level; and then to drain said container, means 'tor circulating an inert gas through said evaporator, said container being seriaily connected to said evaporator for flow of inert gam therethrough and arranged to block such-flow when a predetermined quantity of liquid has collected therein, and'means arranged' to convey liquid refrigerant 'from apart of said evaporator having a high refrigerant' vapor concentration' to a part of said evaporator havinga low refrigerant vapor concentration. v 4 w 5. Absorption refrigerating apparatus comprising means :tor producing refrigerantvapo',

a condenser, an insulated compartnent, a 'water r container, a rreezing coi having portions in heat transfer relationship with said compartment and said container means for intermittently supplying refrigerant discharged from said condenser to said ireezing coil, and means for 'propelling an inert gas through said coil to circulate the liquid refrigerant therethrough as it is evapv said container, means for intermittently supplying refrigerant discharged from said condenser to said reezing coil, means for propelling an inert gas through said coil to circulate the liquid refrigerant therethrough as it is evaporating to produce refrigeration, and said intermittently operative refrigerant liquid supply means including means constructed and arranged to obstruct the flow of inert gas through said coilduring periods when refrigerant is not supplied thereto.

7. Absorption refrigerating apparatus comprising an evaporator, liquid refrigerant producing means, means for intermittently discharging a predetermined quantity of liquid ref'igerant into said evaporator comprising a container, and a syphon connecting said container and said evaporator arranged to become operative when the liquid level in said container reaches a predeterminedlevel and then to drain said container, the

discharge rate of said syphon being greater than the rate at which liquid is supplied to said container, and means for circulating an inert gas throughsaid evaporator, said container being serially connected to said evaporator for flow oi' inert gas therethrough and arranged to block such flow when a predetermined quantityof liquid has collected therein.

8. Absorption refrigerating apparatus comprising an evaporator, liquid refrigerant producing means, means for intermittentiy discharging a predetermined quantity of liquid refrigerant into said evaporator, means for circulating an' inert gas' through said evaporator, and a. liquid circulating drain including a U-shaped loop portion arranged to form a gas'sealing liquid trap connecting the gas inlet and outlet portions of said evaporator, the portion of said drain connected to .the gas inlet portion of said evaporator being positioned to fill said U-shaped portion of -said drain with liquid supplied to said evaporator from said intermittently operative discharge means.

9. An absorption refrigeratingsystem comprising an inert gas. circuit including an evaporator' and an absorber, a boiler, liquid conveying means connecting said boiler and said absorber for flow of absorbing liquid therethrough, means for liquefying .refrigerant vapor generated in said boiler, liquid conveying means for conducting refrigerant liquid from said liquefying means to said evaporator, and means in said liquid refrigerant conducting means for intermittently collecting the refrigerant liquid supplied thereto to alter the operation of the system and for thereafter discharging the collected liquid to allow normal operation of the system to 'ne resumed, said collecting means being included in said inert gas circuit, the arrangement being such that collection of a predetermined quantity of liquid refrigerant will block the flow of inert gas until such collected liquid is discharged, and means arranged to convey liquid refrigerant from a part of said evaporator having a high refrigerant vapor concentration to a part of said evaporator having a low refrigerant vapor concentration.

10. That method of producing' refrigeration i which includes the steps of intermittently supplying refrigerant liquid to an evaporating zone at a rapid rate, propelling an inert gas through the evaporating zone to circulate the liquid but' at a rate insuflicient to evaporate all the liquid supplied thereto, recirculatingunevaporated liquid from the gas outlet portion to the gas inlet portion of the evaporating zone, and evaporating residue liquid refrigerant into the circulating inert gas during periods when no liquid is supplied to the evaporating zone. v

' ARNOLD D. SIEDLE.

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