US1447575A - Eor preventing emui - Google Patents

Description

Mar. 6, 1923.v 14,447,575

. l H. J. SMITH. METHOD' FOR .PREvENmNzG EMULSIFICATION oF REFRIGERAUNG AGENT IN THE SEALINLS QTL!l FILED rfa. 5, 1921. 3 SHE1TTHT L,-

.JPJ- f6 COMPRESSE) GASTO ATTORNEY @6, 1923. 1,447,575. WLSMITH..

METHOD FOR PREVENTING EMULSIFICATION 0F BEFHIGE'RAUNG AGENTZIN THE SEALING OIL.

man 55a. 5,. 1921, s SHEETS-SHEET 2.

ATTORNEY H. 1. SMITH.

Mar. 6, 1923.

METHOD FOR PREVENTIN EMULSIFICATION 0F REFRIGEHATING AGENT IN THE SEALING OIL.

S SHEETS-SHEET 3.

flLE FEB.5.1921.

Patented Mar. 6, 1923.

UlTE S'lrilES 1,447,575 rrENr orrlce.

HAZOR JUDSON SMTH, 0F CHXCAGU, LLNOS. ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, OF ONE-FOUR TH TO WLLABJD REID AND ONE-HALF T0 ALFRED HASTINGS CHAPIN, BOTH OF SPR'INGFIELI), MASSACHUSETT METHOD FR PREVENTING EMULSlEICATION OF ,REFRIGERATING AGENT IN T'IE SEALING OIL.

Application filed February 5, 1921.

fo @ZZ whom t may conce/m:

Be it known that l, .Heron Jonson SMITH, a citizen of the United. States', residing in Chicago. (loolr Coun-ty:y Stater of lllinois, have inifented certain new and useful `Iniprovenients in` Methods for Preventing Emulsiiication of` Refrigeratinn Agent in the Sealing Oil, of which the following is a specification, reference being made to the accompanyingl drawings, forming a part thereof. f

This invention relates to refrigeratingsysf tems of thesmall Lor miniature type; and more particularly to' ice machines of the type designed and intended to be self-operating. l f

Under certain conditions of operation, such as following a relatively long idle or stand periodwhen the compressor may 1be as cold vas the condenserU or folle'wing` a stand period duringwhich the expansion valve has leaked and a. quantity of the refrigerating liquid has more or less flooded theflowside1 by which l mean the coils in the hrine tank, it has been found that7 in ice machines where oil is used as a sealing medium,y Awhenthe machine starts up again some ofthe liquid refrigerating' agent will he drawn directly into the compressor. The compressor and the sealing medium or oil having cooled off or become cold. there is no immediate-ly available heatvto tend to throw olf the refriggcrating gas or liquid to the condenser and the cold oil will rapidly take/on or absorh las or liquid refrigerating agent. Once started. this absorption. increases .rapidly and. instead of the compressor warming up and permittine` Ythe oil and gas or` liquid to separate and i @jas to pass on to the con'- d f 5nd its absorbed refrigeratina` ,r circulated. as a sealing and luhricatin inediuin and injected into the meel' nism a pointhaving a lowerire than the hiojh side. rlhis allows rip "ating agent to boil out ofthe oil, setting up a conrlition of internal refrigerae tion. and thecompressor and sealingmediuin will not colder and colder until the vmachine is actually refrigerating in the compressor, itself. I hen it gets to doing' this it will not x :t itself. too little or no refrigeration is taking place in the expansion coils and the vSerial No. 442,893.

machine will continue to run without doingl Yits work of properly cooling the boX. Y ln the use of ethyl chloride, sulphur dioxide. pictet iuid, methylic ether or ammonia in an oil sealed pump the fundamental conditions leading to supercharging or emulsification are quite similar and the method We have perfected and the valve here shown are nearly indispensable to a reliable machine.

A The use of a stream of water' to cool the condenser and then the compressor brings new factors into the problem of preventing` emulsilication or supercharging. In an air `cooled machine there is bound to vhe a relative balance of the surfaces of the compressor and condenser so far as convection is concerned and the fact that the compressor is the initial source of heat tends to maintain 'during operation a'higher temperature in the compressor than in the condenser. Under ordinary conditions the use of a protective mechanism is limited to the first part of a run after bot-h compressor and condenser `have cooled tor practically air temperature.

,The natural balance of the elements (coinpressor and condenser) naturally protects the poil during runs under ordinary conditions and follow the natural variations of the day.

In a water cooled machinea series of new factors are brought in which either singly or in combination produce pressure-temperature conditions which result in supercharging or'emulsification. lwill enumerate a vfew, of. them. lf the water is allowed to flow yafter the machine stops running` it will chill both condenser and compressor to practically the saine temperature and the machine will immediately emulsify when it starts. lf the stream of water through the cooling system'betoo `great the temperature differential between incoming and discharge water will -be low and therefore the-compressor will run at about the temperature of the condenser and eniulsiiication follows. lf the stream of water is too small for the proper cooling of the machine and condenser then the pressure of the high side will run up to a high point and the machine suffer a loss in efficiency as a result.

f If thewater fails to flow while the machine is in operation the pressure and temperature oit the high side will rise along the pressure-teniperature line of the agent used and the oil will becolne eniulsified or supercharged. lt noir While supercharged the Water cornes into the condenser and thence to the compressor the rapid drop in ternperature ot the condenser will result in a 'apid drop in its pressure with the result that the agent iinpounded in the oil Will boil oli into the condenser and if the temperature drop of, the condenser has been sun'llicientl),7 rapid the boiling agent Will talre the oil with. it int-o the condenser. This puts a machine completely out ot service and leaves the coinpressor Without lubrication or seal. A ina.- chine regulated by therniostatic ineens troni the boi; or brine Will thus run to a brealr-l down and either destroy the compressor or the electric motor.

therefore use in the Water cooled niachines tiro pressure-teinperature valves 2S and d. controls the lion7 or' refrigerating gas to the inlet ot the compressor; and -l is connected in the water line 1]. to the coinpressor 2 and controls the flor." of Water to the compressor. rl`he compressor Water line ll in which the pressure-tempeinture valve el is situated is a ley-pass line troni thctail of the condenser l. A pressure reliet valve. l2 in the discharge line from the condenser situated behind the inlet to the compressor luy-pass forces the Water through the 'bypass it the `valve e be open, otherwise it overiows through the relief valve 'l2 it the conditions Within the compressor hold the pressure-temperature valve in a closed position.

lt will be readily understood from the above description that these Valves 3 and Il: will shut oii the suppl)T of Water to the conipressor jacket and the supply of gas to the compressor it the teanperature-pressure conditions Within the compressor are such as to perlnit eniulsication and these Valves will stag7 closed until the friction of the pump ias raised the ten'iperature ot the conipressor above the danger point. It during the run the low side floods or decided change in the conditions Within the conipressor occur the valves will close unt-il the te;nperatiu'e-pressure has returned to the predetermined point.

To prevent eniulsilication lo a harmful extent the temperature ot the oil when in contact nfith the gas in the high side. must be enough higher than the condensing ternperature (for the given condition. of air or Water teinp atures) 'to present superheated suritaceto the contact et' the gas. This difference in ten'iperature between gas and oil a 1fari.l ile and is atlected b r' the nature oit the oil and the kind ot retrigerating gas used. No hard and fixed rule ,has been arrived at because of the Variable: stated. However *for any'- combinationloi loil land agent there is a Working dierence that is easily obtained by obserration and it is at this point or just above it that We are operating.

In order to establish and hold this predetermined dilierence in temperature We use a pressure-temperature valve as shown .in the accompanying drawing. rllhis valve is automatic and is so constructed that it remains closed until the temperature ot the oil which surrounds it has attained the predetermined diilierence above the temperature of the condenser. rl`he temperature ot 'the condenser is always evidentI in the pressure of the high side along kthe pressure-tempera.- ture curve of the particular agent which is used in the machine. rihereiore we have a pressure in the hieh side ot the machine that corresponds with the temperature ot the liquefied agent in the condenser. lWe use a pressure sensitive element.charged with the sanie liquefied gas as is used :tor the retrigerating process or a` gas ot siniilar pressureteniperature characteristics and this presw sure sensitive element then becomes a teinperature sensitive element and its pressure for temperature will be alo the same liuc or curve as the pressure for temperature curve ot the agent Within the condenser. Now if the temperature ot the compressor and its oil be the same as the temperature of the condenser the element sulnnerged Within the oil Will have a pressure Within it equal to the pressure upon it and therefore in equilibrium. New the valve itself is connected to a diaphragm exposed to the pressure of the high side and therefore the pi vs sure element cannot open the valve to which it is connected until the heat ot the oil and the element itsell is enough higher than the temperature of the condenser to set up a pressure Within the element great enough to overcome the pressure oit the high side on its ends and the pressure ot the high side against the diaphragm which carries the Valve. The relationship of the areas ot the ends of the elenient and the diaphragm determines the ratio ot heat required to open the Valve. or determines how rnurh hotter the compressor nuist be as compared to the condenser before the inachine can open its inlet lines and taire gas trom the @pension coils. Naturally the conm.. sor will heat up rapidly itt the inlet line l shut olL1 the compressor i allowed m pull a high vacuum against the pressure of the con denser. The trictional heat alone Without a negative heatY subtraction is sufficient to heat up the compressor and the oil Within It. is soon after the machine starts to .run as this heat Jfactor or ditl'erei al is developed the lonT side opens aiuomaticall;T and the um chine functions a retrigeratinf; machine Without the possibility oi emulsilication or supercharge of .the oilV c No condition ca for the .condenser water 4it the valve be.

can arise that 4`can cause superchargei as the valve automatically closes olf the low side unless the pressure-temperature condition is favorable and correct.

Under certain conditions kof temperature y and pressure l of the compressor and the y almost certain to emulsify and this re-4 quires a service call for correction.

The obj ect of thisinvention is to produce a method or system that will eliminate these objectionable features by .preventing the supercharging oil.: the sealing oil.

Having thus set. rforth my invention I will now describe an embodiment thereof.

Figure I is a diagrammatic view of my refrigerating system with the pressure temperature valvesconnected in the inlet line and the water vline .of the compressor.

Figure IIillustrates a section through thek compressor online A B.`

Figures III7 IV and V are details of the valve usedvin my system.

Figure VI is a section through the pump i member along the line w-JyFigure I.

Referring now by reference to the rdrawings:

In the diagrammatic sketch Figure II have chosen to illustrate a water cooled machine showing ther condenser l `and compressor 2 with the two .pressure-temperature valves 3 and .4 in the lines Valve Sis in the gas vreturn line yfrom the expansion coils u, 3() and the valve 4 inthe byepass water line from .the tail ofthecondenser.

The valves are submerged'in the `sealing oil in the oil pocket Shown at 5, directly under the oil separator 32 Figure II. The line 6 is the gas discharge line from the compressor oil separatorto .the condenser.

Gas from the expansion coils enters the pres* sure-temperature valve-3,4 at 7 and leave it at 8 thence passing to the inlet of theI compressor at 9. The inlet 9 is in thetace plate l0 which carries the members of the pump or compressor assembly. Water which has been -used to cool the condenser l passes oil".

through thejpipe 1l .and .either flows to the ldrain through the. relief valve AAl2 or lenters the AApressure-temperatnre valve 4v at -118,

.leaves Aitgat .14andr'enters the ,compressor jacket. atll after whichit passes around the icompressor,y absorbing its "heat and leaves the jacket throughfthe overflow atV 16.

The object .of the relief valve 12k inthe line 11 is to set upa back pressure in-that line .which will force the water stream .through the pressure-temperature valve '4 -sion of the element 27, 28 and 29.

closed. By holding r the drawings up to the light you will see a complete refrigeration cycle inf which: blue is the liquid refrige- 4.the cross arm 23 which vis inturn attached by the bolts 24 to the cross arm 25. Sup ported upon the plate 17 by the bolts 26 is the diaphragm head `plate 27 to which is attached the diaphragm 28. The head 29 closes the opposite end of the diaphragm 28 and produces a sealed chamber within the assembly 2'?, k 28 and 29. The formation of the heads 27 and 29 permit of their interlocking rand establishing a limit of expan- This element is rcharged with liquid `retrig: ;erant like that used in the machine or a similar volatile liquid and its gas. Its pressure Jfor temperature curve will be identical with that of the liquid refrigerant within the high side. The kpassage 7 is attached to the line frein the expansion coils andthe passage 8 iszattached to the inlet of the compressor. Now'if the valve be closed the compressor cannot take gas from the expansion coils neither can ity draw liquid refrigerant from a flooded low side.

When the temperature of the oil within the compressor and surroundingthe thermal thermal element. Thepressure of the condenser then pressing` against the head will forcibly close the valve. With the inlet shutr off the temperature of the compressor will 'rapidly rise vbecause of the frictional .heat

of themoving parts and the rapid motion of* the sealing oil through the gears.

.soonas the compressor and the oil within it have-taken on sutlicient heat to raise the ytemperature. of the thermalelelnent to where `its.internal pressure is:` suicient to overcome .the pressure ofthe high side onboth the head29andthe headvv22, the valve will open and because of the tact that. the machine is pulling a high vacuum in the Apassage 8 while the valve is closed; and because` high vacuum will be reduced to the working back-pressure of the machine when the valve this w is open, the relief of that part of the di'f- '.ferential pressure of 22 which was represented bythe high vacuum will let the valve Y" snap open to its limit. This limit is lined by the posit-ion of the plate 27 as related to the closed position ot the valve When the areas of the two heads 29 and 22 are the same the opening point or the valve occurs when the temperature or the oil is at the point Where the pressure for temperature factor Within the thermal element 27, 28, 29 is equal to tvvice the pressure for temperature 'factor in the condenser. With ethyl chloride and a condenser temperature of 8O degrees Fahr., the temperature of the oil necessary to open the valve would be approximately 10S degrees Fahr. Modiiication or the ratios ot areas of the tivo heads will produce any predetermined temperature dii'l'ereutia-l but We tind that ethyl chloride Works best when the above ratio is maintained or exceeded.

By reterrmg` artieularly to Eigure l the gas enters at 7 passes through the thermostatic valve seat 2O coming out at 8, passing through the tube to inlet 9 of the compressor, Which is driven by a motor coupled to drive shaft D, passing through the pump l), the gas and oil enter the oil separator @il and gas are here sepa-rated, the oil drops down into oil pocket 5 and gas is discharged at 6 to the condenser', see Figure il.

rlhe Water from the condenser enters the valve l at 13 and passes out through le to inlet l5 of water jacket or' the compressor l? and out at 16. ln the event the thermostatic valve 4 is closed by internal conditions the water then passes through the check valve l2.

Emulsilication as used in this specilication, means the suspension ot the refrigerating agent in the sealing oil; it is the surcharging ot the oil.

The oil level is shown at line Figure Il' but may be any place so long as the thermostatic valves are submerged.

The method herein described is carried forth by means illustrated, but changes or modifications may be made Without departingl` from the salient features of my invention; and l' therefore intend the following claims to cover such modilications as naturally fall Within the lines of invention.

claim:

l. In a. refrigerating machine or' the type described the combination of means to con trol the heat dissipation of the compressor to maintain the temperature oi the compressor at a point suiiiciently higher than the temperature or thecondenser to prevent the sealing medium Within the compressor 'from absorbing a deleterious amount of the reiirigerating agent and means for closing the suction lipe of the compressor until a predetermined ten'iperature and pressure ratio has been attained Within the compressor.

2. ln a refrigerating machine of the type described the combination With a compres sor and a condenser means for automatically closing the suction line of the compressor when the temperature of the compressor falls to a point as compared With'the temperature of the condenser When harmful emulsiication may occur and opening the suction line to the compressor when a predetermined ratio et temperature has been attained.

3. ln a retrigerating machine of the oil sealed type, the combination with a compressor and a condenser of a temperature-pressure responsive means for closing oit the cooling Water 'from the compressor when the temperature ol" the compressor as compared to the temperature ot the condenser Will permit deleterious supercharging or the oil and open ing the cooling Water circuit when the temp n rature ot the compressor has risen suriciently to overcome the hazard of supercharging.

ln a re'lfrigerating machine of the oil sealed type, the combination or' temperature pressure operated valves which close the suction line ot the compressor and shut orf the cooling Water to the l'compressor when the temperature ot the compressor does not exceed the temperature of the condenser by a predetermined amount and which maintain the valves in the open position when the temjgierature or the compressor exceeds the temperature yof the condenser by the pred ,ermined amount.

o. se a rerrigerating machine of the type described the combination of a condenser cooling circuit1 a compressor cooling circuit using the tail of the condenser stream, a `ssure reliervalve permitting escape of the condenser' cooling stream ahead of the compressor When the compressor Water circuitis closed and means for automatically controlling the stream of cooling medium through the compressor said means'being actuated by the changes in the temperature pressure condition of the compressor, for the purpose set forth.

6. ln a refrigerating machine of the type described, a compressor shell, a rotary pump element Within the shell, an oil body Within the shell, a valve having a temperature sensitive element submerged inthe oil and a diaphragm exposed on one side to the pressure of the high side and exposed upon the other side to a lower pressure, so arranged that the valve remains closed until the temperature surrounding the sensitive element produces a pressure within the sensitive element which exceeds the pressure of the high side a predetermined degree.

7. ln a retrigerating machine of the type described, a valve having a diaphragm eX- posed to the pressure of the high side, a pressure element charged. with the retrigerating agent used in the machine or a volatile agent ot similar physical properties, saiddiaphragm and valve being normally in the closed position as the result of the pressure of the high side upon the said diaphragm and capable of being moved to the open position by the pressure element When the temperature of the pressure element exceeds the temperature of the condenser to a predetermined degree.

8. In a refrigerating machine of the type described the method of preventing emulsiication of, the sealing medium which consists of maintaining the temperature of the sealing medium when exposed to contact With the refrigerating agent in the high side at a point of temperature sufficiently higher than the temperature of the condenser to overcome the tendency of the sealing medium to absorb a deleterious amount of the refrigerating agent.

9. In a refrigerating machine of the type described the method of preventing supercharging of the sealing medium With` refrigerating agent in solution which eonsistsof maintaining the temperature of the sealing medium While exposed to contact with the refrigerating medium in the high side at a point sufficiently higher than the temperature of the condenser to limit the absorption of refrigerating agent to a non-deleterious amount.

10. In a refrigerating machine of the type described, the combination with ya compressor and a condenser of means responsive to the pressure of the condenser and the temthe inlet to the compressor when the temperature of the compressor approaches the temperature of the condenser.

l2. In a refrigerating machine of the type described the combination of a compressor temperature controlling means actuated by the pressure of the condenser and temperature of the compressor and means to open the inlet to the compressor when the temperature of the condenser exceeds the temperature of the compressor by less than a predetermined amount.

13. In a retrigerating machine using oil fin the system which serves as a sealing mekthe temperature at which the oil Will absorb a deleterious amount of refrigerating agent at the Working pressure and the use of means for shutting off the inlet passage to the compressor While the frictional heat of the idling compressor raises the temperature of the oil to the predetermined point.

15. In a refrigerating machine of the type described, the combination with a compressor and a condenser of means Jfor automatically closing the suction line of the compressor when the temperatureI of the compressor falls toa point as compared with the temperature of the condenser at Which harmful supercharging may occur and for opening the same aforesaid line to the compressor when the predetermined ratios of temperature. have been attained.

In testimony whereof, I have signed my name to this specification in the presence of two Witnesses.

n HAZOR JUDSON SMITH. Witnesses:

vWILLARD REID, ELLA M. Trrus.

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