US2240177A

US2240177A - Refrigeration

Info

Publication number: US2240177A
Application number: US181276A
Authority: US
Inventors: Curtis C Coons; Rudolph S Nelson
Original assignee: Hoover Co
Current assignee: Hoover Co
Priority date: 1937-12-23
Filing date: 1937-12-23
Publication date: 1941-04-29
Anticipated expiration: 1958-04-29

Description

April 1941- c. c. COONS ETAL 4 REFRIGERATION Fil ed Dec. -2:5, 1937 Cari'z' s'C. Coon BY 7 Rudofiqh 6'. Nelson Patented Apr. 29, 1941 REFRIGERATION Curtis C. Coons, North Canton, Ohio, and Rudolph S. Nelson, LarchmonhN. Y., assignors to The Hoover Company, North Canton, Ohio, a corporation of Ohio Application December 23, 1937, Serial No. 181,276

15 Claims. (01. 62-1195) This invention relates to absorption refrigeration apparatus and more particularly to means for circulating the fluids therein and for producing efllcient rectification.

More particularly this invention relates to apparatus in which a motor-driven fan is utilized to circulate an inert gas, preferably a. dense inert gas, utilized as a pressure equalizing medium between an absorber and an evaporator, and in which a part of the inert gas is bled ofi from the discharge side of the fan for the purpose of elevating liquid refrigerant to a higher elevation and also for the purpose of directing separate streams of liquid refrigerant to separate destinations.

It is an object of this invention to provide an apparatus in which are combined the advane, tages of a reflux rectifier operating substantially adiabatically and a condenser which extends Well below the evaporator. Heretofore, the designers of refrigerating apparatus have. been greatly hampered by space limitations due to the fact that it was necessary to locate the condenserentirely above the evaporator in order that liquid refrigerant might flow into the evaporator by gravity. Reflux rectifiers are known in the prior aria-however, the priorrectifiers re quire complicated condenser structures in order to provide separate streams of liquid refrigerant, or they rely upon mechanical dividing devices which are uncertain in operation. The present invention achieves the desirable result of permitting the condenser to extend below the evaporator while simultaneously providing positive trouble-free division of the liquid refriger ant with a simple apparatus. y

With our invention it is possible to use a condenser of considerable vertical extent whereby an ample supply of refrigerant is assured 'at all times for rectification and other purposes and all this without exceeding the space limitations inherent in domesticrefrigerators.

vide liquid refrigerant between an evaporator and a reflux rectifier.

An additional object is to provide a refrigerant divider which is also capable of conveying one portion of the refrigerant into the evaporator at a point above the source of liquid refrigerant.

Still more specifically, it is an object of this invention to utilize a dense inert gas such as nitrogen for the purposes just described.

Another object of the invention is to provide for positive circulation of the inert gas and the condensate within a multi-fluid' absorption refrigerating system, and more particularly to provide means whereby said fluids may be divided and circulated at the proper relative rates.

A further important object of the invention is to provide for control of the liquid refrigerant destined for a plurality of separate points by the an adiabatic reflux rectifier in which the liquid It is therefore an object of this invention to provide a construction in which a common means isutilized to circulate the pressure equalizing medium, to elevate the liquid refrigerant into the evaporator, and to divide liquid refrigerant discharged from the condenser into separate streams whereby one of these streams may simple expedient of creating a pressure differential in different parts of the refrigerating system.

It is a further important object of this invention to provide a refrigerating system utilizing without the intervention of movable dividers, orv

flow restrictors.

Other objects and advantages reside'in' certain novel features in the arrangement and construction of parts which will be apparent from the following description taken in connection with the accompanying drawing. in which the figure illustrates a continuous three fluid absorption refrigerating system embodying my invention.

, Referring to the drawing in detail, it will be seen that I have illustrated a refrigerating sys; tem comprising a boiler B, a reflux rectifier R, a condenser C, an evaporatorE, an absorber A, and a. pressure equalizing medium circulating pump Fdriven by a motor G. These elements may be of any desired construction and are diagrammatically illustrated. Preferably the absorber and condenser are air-cooled. The evaporator may be provided with a finned box-c001 duit I I connects the boiler B and a gas separation chamber l2 forming the lower portion of to the boiler B vaporizes refrigerant from the -refrigerant absorbent solution, preferably amand absorption solution are elevated through the I conduit Ii and discharge into the separation chamber I2 wherein the liquid and vapor separate. The refrigerant vapor and entrained absorption solution travel upwardly through the rectifier R across plates I3 which form a tortuous passage therethrough. Refrigerant liquid, which is supplied to the upper end of the rectifier in a manner to be described hereinafter. flows downwardly over the plates l3 and is vaporized by contact with the vapors flowing upwardly through the rectifier R with consequent condensation of absorption liquid vapor entrained in the refrigerant vapor. As a result of this alctionsubstantially pure refrigerant vanor is discharged from the rectifier R through the conduit M which leads'to the upper end of the air-cooled condenser C.

. The refrigerant vapor is condensed by heat exchange with ambient air -passlngover the condenser C and is discharged through a conduit l5 leadingto the lower end of a U-shaped conduit l6 forming a part of a pumping mechanism now to be described.

The legs of an inverted U-shaped conduit ll are connected to the legs of the conduit [6 below the liquid level normally existing in the lower part of the condenser-C. The bight portion of the inverted U-shaped member I? is connected to the high pressure discharge conduit l8 of the fan F by means of a bleed-off conduit I91. The structure just described forms, a pair of connected gas-lift liquid pumps a and b, or a twin gas lift pump, as we prefer to designate it. When the gas fan is in operation astream of dense inert pressure equalizing medium, such as nitrogen, is discharged through' the conduit l9 into the U-shaped conduit I! where it splits into two flow relationship with refrigerant vapor and absorption liquid vapor flowing upwardly there-,

distinct streams, one going to the pump a and one to the pump 12. The inert gas entering that portion of the U-shaped conduit I6 forming the pump a elevates liquid refrigerant therethrough into the evaporator E, and the inert gas entering that portion of the U-shaped conduit l6 forming the pump b elevates liquid refrigerant therethrough into a separation chamber 20.

The inert gas discharged into the separation chamber 20 exits therefrom through a conduit 2| which connects into the discharge portion of the elevating pump a and is carried into the evaporator E. The separation chamber 20 is also connected to the condenser C by means of a vent conduit 22. Liquid refrigerant elevated into the separation chamber; 21 is discharged therefrom through a caudal-Q23 which opens into the top portion of the reflux rectifier R. The conduit 23 includes a U shaped liquid seal portion 24 which prevents vapors from the rectifier or inert gas from the chamber 20 from passing through the conduit 23. An overflow conduit 25 is connected between the conduit 23 and the condenser C just'below the vent 22 which conveys non-condenslble vapors from the condenser.'

The condenser is designed to operate in such fashion that all condensation occurs above the point of connection of the vent 22 thereto;. those portions of the condenser C which are positioned below the vent conduit 22function as a precooler for the liquid refrigerant. The liquid refrigerant discharged into the reflux rectifier R flowsdownwardly .therethrough in counter evaporator.

through in a manner previously described.

The liquid refrigerant discharged through the pump a into the evaporator E flows downwardly therethrough in counterflow relationship with a stream of inert pressure equalizing medium supplied from a source to be described hereinafter.

The liquid refrigerant vaporizes into the pressure equalizing medium to produce refrigeration and the resulting mixture of pressure equalizing medium and refrigerant vapor is discharged from the upper end of the evaporator E through a conduit 26 which passes through a. gas heat exchanger 21 and then connects to the suction inlet of the gas fan F. The pressure equalizing medium refrigerant vapor mixture is discharged under pressure from the gas fan F through the conduit l8 into the lower end of the absorber A.

The weak solution which collects in the lower part of the chamber, l2 by reason of the discharge of the'condult II and the condensation of absorbent vapor in the reflux rectifier R is discharged through a conduit 28, liquid heat exchanger 29; and conduit 30 into the upper end of the absorber A. The lean absorption solution flows downwardly through the absorber A in counterflow to the upwardly flowing stream of refrigerant vapor and pressure equalizing medium whereby to absorb the refrigerant vapor.

The purified pressure equalizing medium exists from the absorber A through the conduit 2% which leads to the gas heat exchanger 21 from which it is conducted into the lower end of the evaporator E by means of the conduit 30.

The strong absorption solutionwhich collects in the lower end of the absorber A is discharged therefrom through a conduit 3| into the solution reservoir S. The strong solution is conveyed' from the reservoir S into the boiler B by means of a conduit 32 which includes the inner member of the liquid heat exchanger 29.

From the foregoing description it will be seen that I have provided a refrigerating system in which the pressure equalizing medium under a slight pressure above that generally prevailing in the system is utilized as an elevating device whereby the condenser may be positioned at any desired level independently of the level of the It .will further be seen that the pressure equalizing medium also functions positively to divide the stream of refrigerant discharged from the condenser whereby a portion of the condensate is separated from the remainder thereof and is conveyed into a reflux rectifier.

Gas is forced through the conduits l9 and I1 whenever the gas pump F is operating; however, the gas discharged through the legs of the conduit i1 is not in a continuous stream but in alternate slugs or bubbles. It has been observed sures a positive and proportional division of the liquid supplied thereto.

While I have illustrated and described but a single embodiment of my invention, it is to be understood that it is capable of expression in other .yariations and constructional forms without departing from the spirit of th invention and the scope of the appended claims.

We claim:

' ing a rectifier, a condenser, and an evaporator in 1. That improvement in the art of refrigeration by means of an absorption system comprising a boiler. a reflux rectifier, a condenser, an evaporator. said vessels all being in open communication. and means for propelling a stream said evaporator, which consists in generatingrefrigerant vapor in the boiler, passing the vapor through the rectifier and into the. condenser to dividing means to prevent by-passing of refrigerant vapor or inert gas around said condenser.

3. An absorption refrigerating system including a boiler assembly, a condenser, an evaporator, and. an absorber connected in circuit to .form a complete system, said system including means for propelling a dense inert gas in a local circuit including said evaporator and said absorber, means for diverting from said localcircuit a portion of said dense inert gas under pressure, means operated by said diverted portion of inert gas operable todirect one portion of the liquid discharged by said condenser to said evaporator wherein it is vaporized by the absorption of heat in the presence of inert gas and for diverting another portion ofsaid condensate to another portion of said system wherein it is vaporized by the absorption of heat in the presence of vapor expelled by said boiler assembly.

4. The method of operating an absorption refrigerating system which includes .the steps of inof an inert pressure equalizing medium through be condensed, injecting a portion of said proopen communication, means for propelling a dense inert gas through a'circuit including said evaporator, means for diverting a portion of said propelled dense inert gas into liquid discharged by said condenser to form a plurality of liquid streams, means for conveying one of said streams intosaid evaporator, means for conveying the other of said streams into said rectifier, said last mentioned means including a liquid seal.

8. Absorption refrigerating apparatus including a rectifier, a condenser, and an evaporator in open communication, means for propelling a dense inert-gas through a circuit including said I evaporator, means for diverting a portion of said propelled dense inert gas into liquid discharged by said condenser to form a plurality 'of liquid,

streams, means for conveying one of said streams into said evaporator, means for conveying the other of saidstreams into said rectifier, saidlast mentioned means including a liquid seal, and an overflow connection between said condenser and said last mentioned means.

-9. Absorption refrigerating apparatus including a rectifier, a condenser, and an evaporator in open communication, means for propelling a troducing propelled streams of inert gas intoconnected columns of refrigerant liquid to ele-- vate the same to a higher elevation, directing the liquid elevated through one of said columns into the presence of a propelled stream of pressure equalizing medium to produce refrigeration, and

directing the liquid elevafid through the other of said columns into contact'with a mixture of refrigerant vapor and the vapor of an absorbent for the refrigerant,

5. In a continuous absorption refrigerating system having a plurality of interconnected parts in open communication, includingan evaporator and rectifier, a- U-tube having the upper ends of the legs thereof connected to said evaportor and to said rectifier, a conduit supplying liquid refrigerant to the lower portion of the U -tube, power-driven means for propelling a pressure equalizing medium through certain of said parts, and means connecting each leg of said U-tube to the discharge side of said power-driven means.

6. Absorption refrigerating apparatus of the type in which an inert gas is employed as apres-t veying the remainder of said liquid to said evaporator.

7.-Absorption refrigerating apparatus includ- 7 dense inert gas through a circuit including said evaporator, means for diverting a portion of said propelled dense inert gas into liquid discharged by said condenser to form a plurality of liquid streams, means for conveying one of said streams into said evaporator, means for conveying the other of said streams into said rectifier, said last mentioned means including a liquid seal, and means venting said condenser and each of said liquid streams into the inert gas circuit.

10. In a continuous absorptionrefrigerating' system havinga plurality of interconnected partsv in open communication, including an evaporator and rectifier, a U-tube having the upper ends of the legs thereof connected to said evaporator and to said rectifier, ,a conduit supplying liquid refrigerant to the lower portion of the U-tube,

power-driven means for propelling a pressure equalizing medium through certain of said parts,- means connecting each leg of said U-tube to the discharge side of said power-driven means, and means for venting pressure equalizing medium from the discharge ends of said U-tube to the suction side of said power driven means.

11. Absorption refrigerating apparatus comprising 'a boiler, a condenser, an evaporator and a rectifier connected in circuit to form a refrigeratin'g system, means for conveying a portion of the liquid refrigerant discharged from said condenser into said rectifier including a gas lift pump, and means for diverting gas into said pump to operate the same from a portion of said system normallyrcontaining thesame.

' 12. An absorption refrigerating system comprising an inert gas circuit including an evaporator and an absorber, means for circulating inert gas through said circuit, a boiler, a recti-' fier connected to receive vapor from said boiler,

means for liquefying vapior discharged from said a rectifier connected to'receive vapor from said.

said evaporator, and means for conveying the.

other body of liquid discharged by said pump to said rectifier.

14. Absorption refrigerating apparatus comprising an inert gas circuit including an evaporator and an absorber, means for circulating an inert gas through said inert gas circuit, a solution circuit including a boiler and said absorber, a rectifier connected to receive vapor from said boiler, means for liquefying refrigerant vapor discharged from said rectifier, a twin gas lift pump for receiving liquefied refrigerant from the liquefying means, means for supplying inert gas to said twin gas lift pump, means for conveying one body of liquid discharged by said pump to said evaporator, means for conveying the other body of liquid discharged by said pump to said inert gas through said inert gas circuit, a solution circuit including a boiler and said absorber,

rectifier, and an overflow means arranged to determine the maximum liquid head on said pump and to discharge into said rectifier.

, 15. That improvement in the art of producin refrigeration by utilizing a refrigerant an absorbent therefor having a higher boiling point than the refrigerant and a pressure equalizing medium inert with respect to the refrigerant and the absorbent which improvement includes the steps of applying heat to a solution of the refrigerant in the absorbent to liberate refrigerant vapor, condensing the refrigerant vapor, directing a plurality of streams of pressure equalizing medium into said condensate to divide the same into a plurality of separate streams, producing refrigeration by conveying one of said streams into the presence of a body of said pressure equalizing medium, and directing another of said streams of condensate into contact with absorbent vapor liberated when heat is applied to the absorption solution whereby the absorbent vapor condenses and additional refrigerant vapor is produced by the heat of condensation of the absorbent vapor.

CURTIS C. COONS. RUDOLPH S. NELSON.