US1758074A - Heat-transforming apparatus - Google Patents

Description

y 1930- R. w. DAVENPORT 1,758,074

HEAT TRANSFORMING APPARATUS Filed March 10, 1927 INVENTOR. Ransom 14 0a venp 0 7 A TTORNE Y.

Patented May 13,1930

PATENT oFFIcEi RANSOM W. DAVENPORT, OF PETROIT. MICHIGAN, ASSIGNOR TO CHICAGO PNEUMATIC TOOL COMPANY, OF NEW YORK, N. Y.,' A CORPORATION 01? NEW JERSEY HEAT-TRANSFORMING APPARATUS Application filed March 10, 1927. Serial No. 174,267.

This invention relates to processes and aparatus for transforming heat and particuarly to refrigerating systems. More particularly it concerns closed cycle refrigerating systems using Working substances of the class which comprises a solution of a lubricant in a volatile liquid. Lubricating refrigerants of the described type are disclosed in my copending application, Serial No. 60,311, filed October 3rd, 1925. Processes and apparatus providing for the circulation of such a lubricating refrigerant through a closed circuitin whichthe volatile component is used for producing refrigeration and the less volatile component for lubrication, are disclosed in my copending application Serial No. 88,164, filed Feb. 15, 1926 of which the present invention is in the nature of an improvement. My last named application relates to the step which involves maintaining a body of lubricant solution under the temperature and pressure of discharge from a refrigerating compressor to give the vapor of the volatile component time to distill off, thus concentrating the lubricant which is then returned hot to the lubricating system of the compressor.

One object of the present invention is to provide improved ways and means for using lubricating refrigerants of the described type. Another object is to control the viscosity of the lubricating ingredient which is fed back to the lubricating system. Other objects will be apparent from the detailed description which follows:

In the present invention, previously disclosed processes and apparatus are improved by the addition of ways and means for performing an additional step with a view to securing better lubrication of the moving parts and'more perfect sealing of thespaoes which must hold compression. It has been discovered that lubricant after having come to equilibrium with the volatile vapor at the temperature and pressure of discharge may then be cooled, thereby increasing its viscosity and improving its sealing and lubricating properties. The cooling step, however, must be performed out of direct surface contact with the hot vapor of the volatile component had to the accompanying drawing which shows diagrammatically a closed cycle refrigerating system with the compressor and associated parts in vertical section.

The essential elements of the refrigerating system disclosed are the pump or compressor, 1., the condenser 2, and the evaporator 3. A suitable feeding device or so called expansion valve 4 controls the feeding of the working substance from condenser 2 to evaporator 3. Since these essential elements of the system may be of any suitable or desired type, the condenser 2 and evaporator 8 are indicated diagrammatically and a conventional form of pump or compressor is illustrated in section. A suitable lubricatin g system is provided for the pump such as a body of lubricant 5 in the crank case arranged to reach the moving parts of the pump by the s lash from the crank shaft and connecting ro s.

In the form of system shown, pump 1 is arranged to withdraw from evaporator 3 through communicating conduit 6, the vapor of the refrigerant and discharge the same into condenser 2 whence the condensate is fed back to evaporator 3 through feeding device 4. As in my copending application Serial No. 88,164, the system provides for the separation of the refrigerant into its volatile and non-volatile components upon the high pressure side of the system at the high temperature of compression and" by fractional distillation. To this end a still 7 is provided between condenser 2 and compressor 1 and into which the compressor discharges through conduit 8. Still 7 is maintained at the desired high temperature to effect fractional distillation of the compressed vapor in any suitable manner as by covering the still with heat insulating material or by the application of heat thereto, if necessary. The fluids discharged by pump 1 are retained in still 7 a sufficient period to enable the components' of the working substance to separate. The distillate or lubricant gathers in the lower part of still 7 .below the inlet opening and is drawn off by a pipe 9 which returns the lubricant to the lubricating system of the compressor, while the vapor of the volatile component of the working substance passes from still 7 by a conduit 10 to condenser 2 and thence back to evaporator 3.

The system as heretofore described does not differ substantially from the disclosure of my aforesaid copending application Serial No. 88,164. The present invention has to do particularly with the treatment of the lubricant after it enters conduit 9 and before it passes into the crank case of compressor 1.

' As shown, pipe 9 is of relatively small bore and of considerable length and extends to a point beneath the crank case of the compressor where it expands into an enlarged cooling coil 9 which extends upwardly and connects with the crank case above'the oil level therein. Connections 9, 9 accordingly form a trap so that the unbalanced pressure due to the crank case tending to run under reduced pressure may be counter-poised by the column of oil in the coil. Any suitable or desired means may be provided for removing heat from the lubricant trapped in coil 9*. The most effective means for this purpose utilizes a cool or cold liquid such as water and by preference coil 9 is arranged to be immersed in such a liquid. To this end a casing 11 encloses the coil and is arranged to be continuously or intermittently supplied with water through pipe 12 which may connect with the water supply for the cooling of cendenser 2 in the event that water is used for that purpose. The cooling water which enters the top of casing 11 passes off into a waste pipe 13. With this arrangement the cooling of the hot oil which is separated out in still 7 is effected practically out of direct surface contact with the hot vapor retained in adiabatic still 7, since the connecting pipe 9 is restricted to a very small area for this very purpose. In consequence the hot oil which passes countercurrent to the cooling water through coil 9 passes into the crank case of compressor 1 in a cool'condit-ion and of much higher viscosity than when it leaves the compressor. By thus maintaining cool oilin the crank case the operating characteristics of the pump are improved and larger clearances are permissible without impairing the operation of the same.

In full detail the operating process of the apparatus herein disclosed comprise the following steps:

1st :-Compressing the vapor of the refrigerant and raising its temperature and pressure in the compressor;

2nd :-Mixing the vapor with lubricantwhich works into the compression space;

3rd z- -Discharging the hot mixture into a vessel or still and adiabatically effecting equilibrium between the vapor phases and the liquid phases of the mixture by allowing the same to remain for a time with the said phases in contact; 0

4th:-Removing some of the liquid phase and cooling it out of contact with the hot vapor phase;

5th :--Returning the liquid at approxi mately the temperature of the cooling medium or environment into the compressor and there using it for sealing and lubrication;

6th :Conducting some of the vapor from the adiabatic still into a condenser and cooling the same to liquefy the vapor;

7th :Feeding the condensed vapor into the evaporator; and b 8th:Evaporating the liquid to produce refrigeration.

While both the process and the apparatus aspects of the invention have been herein disclosed in what is now considered to be a preferred form, it is to be understood that the invention is not limited to the specific details thereof, but covers all changes, modifications and adaptations within the scope of the appended claims.

I claim as my invention:

1. In a closed cycle refrigerating system in which the working substance has dissolved therein lubricant from the lubricating system, the process of continuously separating out said lubricant at the high temperature of compression, extracting heat from the separated lubricant while out of contact with the hot vapor phase of the refrigerating system, and returning the separated and cooled lubricant to the lubricating system.

2. In a heat engine of the compressor-condenser-evaporator type utilizing a working substance having lubricant in solution, the process of transforming heat which coniprises circulating said working substance through said engine in a closed cycle, continuously effecting separation of the lubricant from the working substance at one point substantially adiabatically, removing the separated lubricant from the zone of separation, and removing heat from the separated lubricant to restore its viscosity.

3. In a heat engine of the compressor-condenser-evaporator type utilizing a working substance having lubricant in solution, the process of transforming heat which comprises circulating said substance through said engine in a closed cycle, continuously effecting separation of the lubricant from the worklng substance at one point substantially adiabatically by fractional distillation, removing the separated lubricant from the zone of separation, and removing heat from the separated lubricant to restore its viscosity.

4. In a closed cycle system of the compressor-condenser-evaporator type utilizing mutually soluble substances for refrigeration and for lubrication the process of preventing or nullifying the effects of leakage between the refrigerating system and the lubricating system which comprises the continuous separation of lubricant from the refrigerant substantially adiabatically on the high pressure side of the system and gradually returning the separated lubricant in a relatively cool of the volatile ingredient at the temperature of discharge from said compressor under substantially adiabatic conditions, removing a portion of said solution from contact with said vapor, cooling said portion to approximately the temperature of said condenser, and feeding the cooled solution back to said compressor while condensing, feeding and evaporating the volatile ingredient to transform heat.

6. In a closed cycle system of the compressor-condenser-evaporator type having a lubricating system for the compressor, the thermodynamic process which comprises compressing the Vapor of the refrigerant and raising its temperature and pressure in the compressor, mixing the hot compressed vapor with lubricant which works out of the lubrieating system, retaining the hot discharged mixture at its high temperature to effect separation of the lubricant by fractional distillation, moving the separated lubricant out of contact with the hot vapor phase of the refrigerating system, extracting heat from the separated lubricant, returning the cooled lubricant to the lubricating system, condensing the hot refrigerant vapor in the condenser to liquefy the same, feeding the liquid refrigerant to the evaporator and evaporating the same to produce refrigeration, and continuously repeating the above steps,

7 In a heat engine having a compressor, a condenser, an evaporator, and connections to form a closed cycle system through which the working substance is circulated, a lubricating system for said compressor containing lubricant soluble in said working substance, means operating substantially adibatically at the heat of compression for separating'lubricant from the Working. substance, means for returning the separated lubricant to the lubricating system, and means for restoring the viscosity of the separated lubricant while out of contact with the hot vapor phase of said system.

8. In a heat engine having a compressor, a-

' substance therein and conducting it into said lubricating systems, and means for extracting heat from said separated substance while out of cont-act with the hot vapor phase of said cycle and before it enters said lubricating systems. 1

9. In a heat engine having a compressor, a condenser, an evaporator and connections to form a closed cycle system through which a working substance is circulated, a lubricating system for said compressor containing lubricant soluble in said working substance, means for fractionally distilling out from said working substance at the high heat of compression any lubricant which becomes mixed with said working substance and conducting it into said lubricating system, and means for extracting heat from said separated lubricant while outof contact with the hot vapor phase of said cycle and before it enters said lubricating system.

10. In a heat engine having a compressor, a

condenser, and an evaporator for a working substance comprising a solution of lubricant in a volatile liquid, means for maintaining solution and vapor discharged from said compressor in contact without substantial loss of heat while equilibrium is reached, means for removing a portion of the solution out of contact with the vapor phase and for cooling said portion, and means for feeding said cooled portion into said compressor to lubricate and seal the moving parts thereof.

11. A refrigerating system comprising a compressor, a condenser and an evaporator connected together to form a. closed circuit for the working substance, a lubricating system for said compressor containing lubricant soluble in the working substance, thermally operated means intermediate said compressor and said condenser for continuously separating out lubricant from said working substance, means for moving said separated lubricant out of contact with said thermal means, and means for extracting heat from said separated lubricant and feeding the same to said compressor.

12. A heat engine utilizing a working substance containing lubricant in solution comtrap in said connection, and means for cooling the lubricant in said trap. I

13. A heat engine utilizing a working substance containing lubricant in solution comprising a compresser, a condenser and an evaporator connected together to form a closed thermodynamic circuit, a still in the connection between said compressor and said condenser for separating the lubricant from the volatile component of the working substance, a connection for conducting the lubricant from said still to said compressor, said connection having means for maintaining a body of the lubricant substantiallyout of contact with the hot vapor in said still, and means for cooling said body of lubricant.

14. A heat engine utilizing a working substance containing lubricant comprising a compressor, a condenser and an evaporator connected together to form a closed thermodynamic circuit, a still in the connection between said compressor and said condenser for separating the lubricant from the volatile component of the working substance, a connection for conducting the lubricant from said still to said compressor, said connection providing a trap and having a restricted portlon exposing only a small surface area of lubricant to the hot vapor in said still, and means directing cooling fluid counter-current to the movement of lubricant in said trap.

15. A heat engine utilizing a working substance containing lubricant' comprising a compressor, a condenser and an evaporator connected together to form a closed thermodynamic circuit, a still in the connection between said compressor and said condenser for separating the lubricant from the volatile component of the working substance, a connection for conducting the lubricant from said still to said compressor, said connection providing a trap and having a restricted portion exposing 0111 a small surface area of the lubricant to the liot vapor in said still, and means for immersing said trap portion of said connection in cooling liquid.

16. Refrigerating apparatus utilizing a. working substance containing lubricant in solution comprising a compressor, a condenser and an evaporator connected together to form a closed thermodynamic circuit for said working substance, a still in the connection between said compressor and said condenser arranged to operate substantially adiabatically at the heat of compression for separating out the lubricant component of the working substance by fractional distillation, means for feeding the separated lubricant to the crank case of said compressor including a conduit of restricted bore and of substantial length providing a trap, and means for bringing the trapped lubricant into thermal contact with a cooling fluid to remove heat from and to increase the viscosity of the lubri cant.

17. Refri crating apparatus utilizing a working su stance containing lubricant in solution comprising a compressor, a condenser and an evaporator connected together to form a closed thermodynamic circuit for said working substance, a still in the connection between said compressor and said condenser arranged to operate substantially adiabatically at the heat of compression for separating out the lubricant component of the working substance by fractional distillation, means. for feeding the separated lubricant to the crank case of said compressor including a conduit of restricted bore and of sub stantial length terminating in a coil forming a trap and means for passing cooling fluid over said coil to cool the separated lubricant and to increase the viscosity of the same.

18. Refrigerating apparatus utilizing a working substance containing lubricant in solution comprising a compressor, a condenser and an evaporator connected together to form a closed thermodynamic circuit for said working substance, a still in the connection between said compressor and said condenser arranged to operate substantially adiabatically at the heat of compression for separating out the lubricant component of the working substance by fractional distillation, means for feeding the separate lubricant to the crank case of sa1d compressor including a conduit of restricted bore and of substantial length merging into an ascending coil of increased size, a casing enclosing said coil, and means for passing water through said casing and over said coil counter-current to the movement of lubricant therein for removing heat from and for increasing the viscosity of the lubricant.

Signed by me at Detroit, in the county of Wayne and State of Michigan, this 7th day of March, 1927.

RANSOM W. DAVENPORT.

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