US1769113A - Refrigerating process and apparatus - Google Patents

Description

3y 1, 1930. R. w. DAVENPORT 1,769,113

REFRI(FrERA'IINCr PROCESS AND APPARATUS Filed Aug. 3, 1926 I N V EN TOR. Famsom 14/. 0a ven p or 7 A TTORNE Y.

Patented July 1, 1930 UNITED STATES PATENT OFFICE RANSOM W. DAVENPORT, OF DETROIT, MICHIGAN, ASSIGNOR TO CHICAGO PNEUMATIC TOOL COMPANY OF- NEW YORK, N. .Y., A CORPORATION OF NEW JERSEY REIBIGEBATING PROCESS AND APPARATUS Application filed August 3, 1926. Serial No. 126,782.

This invention relates to processes and apparatus for producing heat transforming effects with particular reference to closed cycle systems utilizing lubricating Working substances of the type disclosed in my copending application Serial No. 60,311 filed October 3, 1925, and distinguishes in certain important respects from m previously disclosed methods and means or producing refrigeration with a lubricating refrigerant whose physical constitution resembles a solution of viscous and volatile liquids, as set forth in my copending applications, Serial No. 85,580 filed February 2nd, 1926; Serial No. 88,164 filed February 15th, 1926; Serial No. 95,531 filed March 18, 1926; Serial No. 106,825 filed May 5th, 1926; and Serial No. 106,826 filed May 5, 1926.' These previous disclosures all involve the concentrating or thickening of the working substance for lubricating purposes and the feeding of the thickened liquid to the pump. Such feeding of the lubricating concentrate, however,

is substantially continuous and is effected largely by gravity so that the pump) necessarily must be on a lower level or eneath the evaporator containing the working substance. 4

One object of the invention is to devise processes and apparatus for utilizing lubricating refrigerants Without restriction as to the position of the pum relative to other parts of the apparatus. other object is to permit the eriodic return of the concentrated solution to ortowardsthe ump.

Other objects will be apparent from t e de-' tailed description of the invention which follows.

In carrying out the present invention the ste common to my previous disclosures which involves the returnin of the concentrate to the pump is also per ormed, but in a different manner and by means of different apparatus, so that the usual machine unit which contains the pump may be placed above the evaporator if desired. My improved process contemplates periodically interrupting the withdrawal 0 the vaporized worklng substance from the concentrating chamber in order to draw concentrate therefrom for lubricating purposes. The change in the fluid'being withdrawn is effected in alternation and entirely automatically. The automatic regulation ma be controlled by the variations of the liquid level in the concentrating chamber and the change is preferably instantaneous. The concentrated lubricating 'liquid'which is withdrawn may be passed directly to the pump or other pressure reducing device if the latter is adapted to handle surges of liquid, or'it may be stored and fed in small amounts. The invention further comprises suitable apparatus for practicing the improved process.

In order to illustrate the invention and the manner of its use one form and arrangement of apparatus is shown in the accompanying drawings in which:

Fig. '1 is a view largely diagrammatical in character of a refrigerating system; and

Fig. 2 is a view on an enlarged scale'partly in section and partly in side elevation of the automatic. control apparatus.

The apparatus diagrammatically indicated in Flg. 1 for practicing my improved process consists essentiall of an evaporator A disposed in the'f'zone rom which heat is to be extracted as in the storage compartment of a refrigerator, a pump or compressor B and a condenser C,these parts being connected together to form a closed cycle system. The parts with the possible exception of the evaporator A may be of any suitable or desired type, a prime mover 0 some kind (not shown) being necessary to drive pump B.

Evaporator A terminates in-a concentrating vessel A, the outlet a of the evaporator proper being disposed adjacent the top of concentrator A so as to permit a body of J spaced from the bottom of tinct from conduit D it is shown as connect- I.

ing with conduit D at point d adjacent pump B. Condenser C connects with evap-' orator A through a conduit F controlled by a valve or expansion device G of any suitable or desired type.

The s stem is arranged to operate with a lubricatlng working substance consisting of a mixture of a volatile liquid and a lubricant, such as disclosed in my aforementioned copending application, Serial No. 60,311 filed October 3, 1925. A typical working substance is methylene chloride having grease in solution in the proportions of 85% methylene chloride and 15% grease. A body of this liquid mixture is placed in evaporator A and in the concentrator chamher A. On starting pump B, it will be evident that the-gaseous contents of the eva orator AA including the vapor of the wor 'ng substance will be withdrawn through both conduits D and E if the same are open and if the body of liquid is at or about the level indicated at w. With the proper amount ofworking substances in the system, the concentrated lubricant will gradually accumulate in concentrator A raising the level of the liquid therein above the opening to conduit E whereupon the vapor of the working substance will continue to be drawn off through conduit D.

With the liquid level standing above the 0 ening to conduit E, it will be evident that ii the opening to conduit D is closed the entire suction effect of. pump B will operate through conduit E to draw liquid from concentrator A and discharge it into pump B. The means for restricting or closing the vapor line while the concentrate is being sucked up are preferably'automatic in operation. Such means may comprise a float controlled by the level of the liquid in concentrator A operating a snap valve disc on to and oil the vapor pipe inlet when the liquor is respectively high and low in level. The variation in the level may be great so that the liquid is drawn away only at rare intervals, or small,.in which event the liquid will be drawn away more frequently.

In the form' shown conduit D carries adjacent its extremity a collar 3 having projections or ears 4 (Fig. 2) in which is mounted a shaft or pivot- 5. A float-member 6 is mounted upon pivot 5, also a closure plate 7 for the open end of conduit D. Float member 6 is arranged to operate closure 7 with a snap action by means of a coiled spring 8 secured atone end to member 6 at a point 9 s aced from pivot 5 and at its other end to c osure 7 adjacent the outer extremity ofthe latter. By suitable disposing members 6 and 7 relative to each other and b connecting the spring, 8 thereto at suita le spaced points member 6 will throw valve 7 in response to predetermined variations in the level of the liquid in concentrator A. With the arrangement shown closure valve 7 will open when the liquid level is at w and close when the liquid is at y. With the float in its lower position and valve 7 open, the pull or lie of the spring 8 is indicated bythe full line indication of the spring in Fig. 1 and by the broken line m in Fig. 2. With the rise of the liquid to the y level the position of the float is indicated in broken outline in Fig. 1 and in full lines in Fig. 2, the pull of spring 8 upon the open valve then being indicated by broken line at (Fig. 2). This causes the valve to move toits closed or full line position shown in Fig. 2. With the fall 0 the liquid level to a: the inclination of the-float is indicated in full lines in Fig. 1 and in broken lines in Fig. 2. The pull of spring 8 upon the closed valve indicated by broken line 0 (Fig. 2 is such as to cause the valve 7 to move to open position. A stop 11 may be provided to fix the extent of opening of valve 7. With the parts so far described it will be'apparent that when the system is in operation the gaseous and the liquid contents of concentrating chamber A are withdrawn by pump B in alternation. The periods during which conduit D is open for the withdrawal of vapor are preferably longer than the periods during which conduit E is receiving the total suction effect of the pump to withdraw li uid, a proper arrangement and adjustment 0 the float control mechanism being efiective to establish the duration of such periods and the quantity of liquid withdrawn at any one time.

If pump B is not adapted to handle surges of liquid such as will result when conduit' D is closed, or if the lubrication of the pump will be better accomplished by a gradual feeding of the concentrate, suitable means may be provided for storing the liquid withdrawn from chamber A and erinitting it to pass in limited amount to t e pump. One manner of effecting this result is shown in Fig. 1 wherein conduit E .isenlarged at E to form a chamber in which is positioned beneath the open end of the conduit a receptacle E for the li uid concentrate. This receptacle may be o any desired size so as to hold the entire charge or only a part thereof and the bottom of the receptacle is formed with a small opening as'indlcated to .permit a dribble of liquid into the conduit the liquid passes oif as vapor leaving the prises disposing a body of the working subconcentrated lubricant to be periodicallyrestance in the zone from which heat is to be moved through pipe E. While the invention extracted, reducing the pressure on said body is applicable to conventional refrigerating to produce vaporization of the volatile liquid systems, in which the working substance is so .as to cause a heat absorbing effect and vaporized by straight pumping, it has parto concentrate the lubricant, periodically ticular-application to closed cycle systems stopping the removal of vapor to withdraw operating on the vapor-gas'principle as disconcentrate for lubricating purposes, returnclosed in my copending application, Serial ing the withdrawn fluid to said bod after No. 15,172, filed March 19, 1925. Fig. 1 illuscondensing the vapor and diluting t e con trates either system since the characterof centrated lubricant with the condensate, and the feeding device G determines the operat controlling the periods of vapor and liquid ing characteristics of the system. If device withdrawalautomatically in response to G is arranged to passliquid only, the sys: variations in the level of said body.

tem operates in the conventional manner by to pass a stream of gas, vapor and liquid the liquid and a lubricant, the process of refrigsystem operates on the vapor-gas principle. eration which comprises disposin a body of The vapor-gas arrangement eflects a greater the liquid mixture inthe zone'o? refrigeraconcentration of the lubricant since the contion, withdrawing in alternation first the tents of the evaporator chamber E under vapor of the liquid and then the liquid itthis s stem are drawn oif at approximately self, the former to cause absorption of heat the hlghest temperature obtaining in the and to effect concentration of the liquid and chamber in which evaporator A. is mounted the latter for lubricating purposes, storing rather than at the relatively low uniform the withdrawn liquid and feeding it contemperature of the, working substance as stantly in limited amount to the parts rein conventional systems. quiring lubrication, condensing the vapor,

With the arrangement herein disclosed the diluting the liquidwith the condensate, and vapor conduit is normally wide open and no. returning the liquid so diluted to said body. loss of efiiciency through wire drawing is, 4.-. In a closed cycle system utilizing as a occasioned. Yet the machine unit which inworking substance a mixture of a volatile cludes the pump may be at any reasonable liquid and a lubricant, the process of refrigheight above the evaporator since the full eration which comprises disposing'a bod of pressure difference of the two sides of the the liquid mixture in the zone of rerigsystem is available to lift the concentrate. eration,'withdrawing in alternation first the While the process and apparatus aspects vapor of the liquid and then the liquid itof the invention have been described in what self, the former to cause absorption of heat is now considered to be their preferred and to effect concentration of the liquid and forms, it is to be understood that the inthe latter for lubricating purposes, storing vention is not limited to the specific details the withdrawn liquid and feeding it conthereof but covers all changes, modifications stantly in limited amount to the parts reand adaptations within the scope of'the apquiring lubrication, condensing the vapor,

pended claims. diluting the liquid with the condensate, re-

I claim asvmy invention: turnlng the liquid so diluted to said body, 1. The process of refrigeration with a and controlling the periods of vapor and working substance consisting of a volatile liquid withdrawal automatically in response liquid and a lubricant in solution which to variations in the level of said body.

comprises dis osing a body of the working 5. In a refrigerating system, in comblnasubstance in t e zone from which heat is to ,tion, an evaporator for containing a liquid be extracted,reducing the pressure on said to be evaporated, a pump, a plurality of .body to produce vaporization of the volatile fixed connections between said pump and liquid so as to cause aheat absorbing effect said evaporator, means controlling at least and to concentrate the lubricant, periodione of said connections to cause said cally stopping the removalof vapor to withto withdraw either the gaseous or the iqui draw concentrate for lubricating purposes, contents of said evaporator, and a condenser returning the withdrawn fluids to said body rc elving thedlscharge from said pump and after condensin ,the vapor and diluting the directing the same to said evaporator. concentrated lu ricant with the'condensate, 6; In a refrigerating system, in comblnaand controlling the periods of vapor and 51011, an evaporator forcontamlng a liquid liquid withdrawal automatically in response t be eyaporated, a pump, a plurality of to the operating characteristics of the fixfid nnectlons be ween saldpump and system. said evaporator, me ans controlling at least 2.The -process of refrigeration with a one of said connections so that said pump working substance consisting of a volatile withdraws the gaseous contents of said liquid and alubricant in solution which comevaporator for a given period and then 3. In a closed cycle system utilizing as astraight pumping. If device G is arranged .working substance a mixture of a volatile withdraws liquid only from said evaporator, and means for removing heat from the liquid and vapor discharged from said pump before returning the same to said evaporator.

7. In a refrigerating system, in combination, an evaporator for containing a liquid to be evaporated, a pump, connections from said pump to said evaporator so arranged that one draws liquid and the other gas, means operating with a' snap action automatically at intervals to cause said pump to withdrawfrom said evaporator. in alternation either the gaseous or the liquid products thereof, and a condenser in the connection from said pump to said evaporator.

8. In a refrigerating system, in combination, an evaporator foncontaining a liquid to be evaporated, a pump, connections from said pum to said evaporator so arranged that one rawsliquid and the other gas, control means for'at least one of said connections operating automatically with a snap action in response-to changes in the level of the liquid in said evaporator for causing said pump to withdraw in alternation from said evaporator either the .gaseous or the liquid products thereof, and condensing means in the connection from said pump -to said evaporator.

9. In a refrigerating system, in combination, an evaporator containing a refrigerant solution, a pump, a connection from sa1d pump to said evaporator for gas, a. connection from said pump to said evaporator for liquid, a valve for closing-said gas connection, means for effecting a quick action of said valve, and connecting means including a condenser from said pump to said evaporator.

10. In a refrigerating system, in combination, an evaporator containing a refrigerant solution, a pump, a connection from said pump to said evaporator for gas, a connection from said pump to said evaporator for liquid, a valve for closing said gas connection, a float device controlled by the level of said solution, means connecting said device to said valve arranged to be offcentered by the movement of said device to throw said valve with a snap'action, and a connection from said pump to said evaporator including a condenser.

11. In a heat transforming system the combination with a concentrating evaporator containing a lubricating refrigerating solution, of a pump adapted to evaporate and to be lubricated by said solution,a connectionbetween said pump and said evaporator for vapor, a connection between said pump and said evaporator for liquid, control means for one of said connections with in evaporator and operating automatically'with a snap action in response to the operating conditions of the system, and a return connection from said pump to said evaporator including a condenser.

12. In a heat transforming system the combination with a concentratin evaporator containing a lubricating refrigerating solution, of a pump adapted to evaporate and to be lubricated by said solution, a connection between said pump and said evaporator for va'por, a connection between said pump and said evaporator for liquid, means comprising a float controlled by the liquid level in said evaporator acting to close said vapor connection while said liquid level is between predetermined limits, and a condenser forming a part of the return connection from said pump to said evaporator.

13. In a refrigerating system, in combination, a concentrating evaporator containing a lubricating refrigerant solution, a pump adapted to evaporate and to be lubricated by said solution, means whereby said pump withdraws either vapor or liquid from said evaporator, means for feedin the liquid withdrawn by said pump in limited quantity to said pump to lubricate the same, and means including a condenser for returning the discharge of said pump to said evaporator.

14. refrigeranting system comprising a concentrating evaporator containing a lubricating refrigerating solution, a pump, a connection for vapor from said evaporator to said pump, a connection for liquidfrom said evaporator to said pump, means operating automatically and periodically to close said vapor connection, means in said liquid connection for storing liquid and feeding it at a predetermined rate to said pump, and a connection from said pump to said evaporator including a condenser.

15. A refrigerating system comprising a concentrating evaporator containing a lubricating refrigeratlng solution, a pump, a connection for vapor from said evaporator to said pump, a connection for liquid fromsaid evaporator to said pump, means controlled by the level of the solution in said evaporator for automatically and periodically closin I said vapor connection, a receptacle in sa1d liquid connection for intercepting and storing liquid withdrawn from said evaporator, said rece tacle having a restricted opening for ceding the liquid at a predetermined rate to said pump,

and a connection from said pump to said evaporator including a condenser.

Signed by me' at'Detroit, Wayne County, Michigan, this 30th day of July, 1926.

RANSOM W. DAVENPORT.

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