US2538861A

US2538861A - Refrigeration expansion valve

Info

Publication number: US2538861A
Application number: US777198A
Authority: US
Inventors: Franklyn Y Carter
Original assignee: Detroit Lubricator Co
Current assignee: Detroit Lubricator Co
Priority date: 1947-10-01
Filing date: 1947-10-01
Publication date: 1951-01-23
Anticipated expiration: 1968-01-23

Description

Jan. 23, 1951 F. Y. CARTER 2,538,861

REFRIGERATION EXPANSION VALVE Filed Oct. 1, 1947 v 3 Sheets-She'et 1.

INVENTOR.

ATTQRNEY Jan. 23, 1951 Filed Oct. 1, 1947 F. Y. CARTER REFRIGERATION EXPANSION VALVE 5 Sheets-Sheet 2 INVENTOR.

BY y

ATTORNEY Jan. 23 1951 F. Y. CARTER 2,538,861

REFRIGERATION EXPANSION VALVE Filed m. 1, 1947 s Sheets-Sheet 3 2 mmvrm 4 [WW M/ WK M 1 [44:0 ATTORNEY Patented Jan. 23, 1951 REFRIGERATION EXPANSION VALVE Franklyn Y. Carter, Dearborn, Mich., assignor to Detroit Lubricator Company, Detroit, Mich., a

corporation of Michigan Application October 1, 1947, Serial No. 777,198

8 Claims.

This invention relates to new and useful improvements in refrigeration expansion valves.

One of the objects of this invention is to provide a refrigeration expansion valve having new and improved control means therefor.

Another object is to provide a gas charged expansion valve having means to vary the maximum operating pressure thereof.

Another object is to provide an air conditioning system utilizing an expansion valve having a variable maximum operating pressure to control dehumidification of the air.

Other objects will become apparent from time to time throughout the specification and claims as hereinafter related.

In the accompanying drawings, to be taken as a part of this specification, ther are clearly and fully illustrated several preferred embodiments of this invention, in which drawings:

Figure l is a diagrammatic view of a refrigerating system having an expansion valve with an expansible chamber for controlling maximum operating pressure of the valve and a thermostatic bulb element for controlling said expansible chamber, the expansion valve and expansible chamber being shown in vertical cross-section,

Fig. 2 is a view in elevation of an expansion valve similar to that shown in Fig. 1 with the upper portion of the valve shown in brok 11 section and having an expansible chamber for controlling the maximum operating pressure of the valve, the expansible chamber being controlled by a thermal expansive element,

Fig. 3 is a diagrammatic view of a refrigerating system utilizing the valve and expansible chamber shown in Fig. 2,

Fig. 4 is a diagrammatic view of a refrigerating system including an expansion valve and expansible chamber similar to that shown in Fig. 2 but having an electrically operated heat motor for controlling the expansible chamber, the expansible chamber being shown enlarged and in partial section,

Fig. 5 is a diagrammatic view of an expansion valve having an expansible chamber shown in section, the expansible chamber being pneumatically controlled, and

Fig. 6 is a diagrammatic view of a refrigerating system having an expansible chamber shown in section, the expansi'nle chamber being controlled by a manual adjustment screw.

Referring to the drawings by characters of reference in Fig. 1 there is an air conditioning system comprising a refrigerant compressor l driven by a motor 2 supplying compressed refrig' rant to a condenser 3 which is in turn connected to a liquid refrigerant receiver 4. A conduit 5 runs from the receiver 4 to an expansion valve 8 which controls flow of refrigerant to an evaporator I, the evaporator 1 being connected by a conduit 8 to the suction side of the compressor l. The refrigerant evaporator l is positioned within an enclosure 9 and is operable to cool air circulating therewithin. The refrigeration expansion. valve '6 is a conventional gas-charged thermostatic expansion valve comprising a movable valve member In which is urged towards a valve seat II by a spring l2. The expansion valve 8 has a pressure responsive diaphragm 13 which is operable through a thrust rod [4 to vary the opening of the valve member [0. There is an adjustment screw member l5which is operable to vary the compression of the spring I2 thereby to determine the superheat setting for the valve. A cover member l6 encloses a space I! over the pressure responsive diaphragm l3 and is operable to receive gas1ous pressure for the operation of the diaphragm l3. From the cover member I6 a conduit I8 runs to a maximum operating pressure control member i9 which is in turn connected by a conduit 20 to a thermostatic bulb element 2| positioned'at the outlet end of the evaporator l. The thermostatic bulb element 2i contains a volatile liquid for transmitting gaseous pressure to the space ll enclosed above the diaphragm l3 of the expansion valve 6. The amount of volatile liquid contained in the bulb element 2 I, the conduits l8 and 20, and the space I! is such that all of the same may be contained within the space ll. The control member l9 comprises a body member 22 having a transverse passageway 23 therethrough and a cap or cover member 24 screw-thnadedlycarried thereby as at 25. The body member 22 has a cylindrical cavity or chamber 26 therein communicating with a cylindrical cavity 21 of smaller diameter into which opens the passageway 23. Positioned in and sealing the opening from the chamber 26 is a flexible hollow bellows 28 having a spring 29 positioned against the end thereof and urging the same towards a compressed position. There is a thrust member 30 positioned at the open end of the bellows 28 and having an annular flange portion 3| and a cylindrical projecting portion or tongue 32 hearing against the inner face of the end wall of the bellows 28 in opposition to the spring 29. The cap member 24 has an annular shoulder portion 33 cooperable with the annular flange portion 3| of the thrust member 30 and operable to limit movement thereof in the direction of thrust of the spring 29. The cap member 24 has an aperture 34 centrally positioned the conduit 39 to the bellows 38.

perature of the air circulating over the bulb elein th end wall thereof and a cylindrical plug member screw-threadedly positioned therein. The plug member 35 has a longitudinal cylindrical aperture 36 extending therethrough. The plug member 35 terminates inside the cap member 24 in an annular disc portion 31 which has a flexible hollow bellows 38 secured thereto having a closed end wall bearing against the thrust member 30. The aperture 36 in the plug membLr 35 opens into the hollow interior of the bellows 38 and is operable to receive a conduit 39 leading to a thermostatic bulb element 40.

In operation this expansion valve and system functions as follows:

During normal cooling operation air is circulated within the enclosure 9 and heat removed therefrom by the refrigerant evaporator which is controlled by the expansion valve 6 functioning as a conventional gas type thermostatic expansion valve. The maximum operating pressure control member |9 is shown in an intermediate position of operation, itsnormal position being with the thrust member 3!! moved into engagement with the face of the body member 22 and the bellows 28 fully expanded. When the bellows 28 are fully expanded the volume of the space enclosed within the member l9, i. e. the

space

25 and 21 and passageway 23, is at a minimum value. The bulb element is positioned in the path of circulating air within the enclosure 9 and contains a volatile liquid which is responsive to the temperature of such circulating air and is operable to transmit pressure through As the temment 40 to the evaporator 1 decreases the pressure in the bellows 38 will decrease permitting the spring 29 to force the bellows 28 towards a collapsed position. As the bellows 28 is forced towards collapsed position the volume of space en-- closing the volatile liquid and its vapors from the bulb element 2| is gradually increased thereby permitting the volatile liquid in the bulb element 2| to enter the gas phase in greater quantity until all of said volatile liquid will be in the gas phase when the bellows 28 has been compressed to a position limited by engagement of the annular flange 3| of the thrust member 36 with the annular shoulder 33 of the cap member 24. It is then seen that as the temperature 1 of air circulating over the bulb element 40 is -decreased the bellows 28 is compresed thus increasing the volume of the space enclosing the volatile liquid from the bulb element 2| and eventually permitting all of the same to enter the gas phase. The expansion of the space enclos- I ing the volatile liquid from the bulb element 2| ture due to increased throttling through the expansion valve. The starving of the evaporator 1 and lowered temperature of the portion thereof is operable to cause greater amounts of moisture to be condensed thereon thereby increasing the rate of dehumidification of the air circulating within the enclosure 9-. It is seen then that this system provides a novel means for controlling the dehumidiflcation of air within an air conditioning system. In normal operation the air passing over the evaporator is cooled and continuously circulated within the enclosure 9. the cooling being principally the removal of sensible heat. When the temperature of the air circulating within the enclosure 9 drops to a predetermined value the bellows 28 in the control member l9 has been compressed a predetermined amount suflicient to increase the volume of the space enclosing the volatile liquid controlling the diaphragm |3 of the expansion valve 6 thereby decreasing the pressure of the same causing increased throttling of refrigerant passing to the evaporator 1 thereby to starve the evaporator l and increase the rate of dehumidification as heretofore described.

In Fig. 3 there is a diagrammatic view of an air conditioning-or refrigerating system similar to that shown in Fig. 1 comprising a compressor driven by a motor 2 supplying refrigerant to a condenser 3 which is in turn connected to a receiver 4. The receiver 4 is connected by a conduit 5 to an expansion valve 6 which is in turn connected to a refrigerant evaporator I from which a conduit 8 leads to the suction side of the compressor There is a thermostatic bulb element 2| connected by a conduit 20 to a cover member l6 in the expansion valve 6. In this form of the invention, however, the maximum pressure control member I9 is connected in parallel with the bulb element 2| rather than in series, it being connected by a conduit 4| to the cover member 6 of the expansion valve 6. In Fig. 2 the expansion valve 6 shown in the system of Fig. 3 is enlarged, partially broken away and the control member I9 is shown in vertical section. In this form of the invention all parts or portions of parts which are common or essentially common to those in Fig. 1 will be given the same ref.rence numbers and duplication of terminology given will thereby be avoided.

. The expansion valve 5 in Fig. 2 is shown only in suflicient detail to show the connection to the control member l9 inasmuch as the detail construction of the valve is immaterial, it being merely a conventional gas charged thermostatic expansion valve. The control member H] in Fig. 2 is similar to that shown in Fig. l with a slight change in that the bellows 28 of Fig. 1 has been replaced with a flexible diaphragm 42. In the control member IQ of Fig. 2 there is an annular dish-shaped member 43 having a flexible diaphragm 42 thereacross which is held in position and sealed thereto by a cover member 44. The cover member 44 and diaphragm 42 enclose an expansible and contractable chamber 45 which is communicable with the space ll above the flexibl diaphragm l3 of the expansion valve 8 through the conduit 4|. There is a body member 46 carried by the annular dish-shaped member 43 which carries a thermostatic control member 4'1. The thermostatic member 41 comprises an annular hat-shaped member 48 and encloses a thermostatically expandible material 49 having a high rate of expansion in passing from the solid to liquid states. There is an annular sleeve member 56 to which the hat-shaped member 48 is secured by an annular flange portion 5|, the sleeve member 50 extending into the hollow interior of the body member 46. There is a flexible diaphragm 52 sealed and secured by the sleeYQ member 50 and th hat-shaped member assaaer 48 for transmitting the expansive force of the expansive material 48. The sleeve member 88 has an annular disc member 88 at its upper end which has a spring 54 bearing thereagainst at one end and against the end wall of the body member 48 at the other end for holding the thermostatic member 41 yieldably secured thereto. The sleeve member 58 is hollow and has a longi-" tudinally movable piston member 55 positioned -therein. A cylindrical plug member 88 is positioned between the flexible diaphragm 52 and the piston member 55 and is operable to transment 41 is positioned in the path of circulating air and is operable to respond to the temperature thereof. At higher temperatures the expansive material 49 is expanded and the

pistons

55 and 58 move to an extreme upward position compressing the diaphragm 42 against th inner face of the cover member 44 thereby decreasing the volume of the cxpandible chamber 45 to a minimum value. As the temperature of air circulating within the enclosure 9 decreases the temperature of the thermal expansive material 49 likewise decreases causing the same to contract permitting the

pistons

55 and 58 to move downward and the diaphragm 42 to move away from the inner face of the cover member 44 thereby increasing the volume of the chamber 45 and providing the heretofore described adjustment of maximum operating pressure of the expansion valve 8.

In the form of the invention shown in Fig. 4 there is a refrigerating system very similar to that shown in Fig. 3, the essential difference being in the means for adjusting the volume of the maximum operating pressure control member I9. The member l9 comprises an annular dishshaped member 88 havin a flexible diaphragm 8| positioned thereacross and sealed thereto by a dish-shaped cover member 82. The diaphragm 8| divides the space between the cover member 82 and the dish-member 88 into two

chambers

83 and 84. There is a conduit 85 leading from the cover member 82 and chamber 83 to a T con nection 88 joining the conduit 28 from the bulb element 2| and the conduit 8 leading to the expansion valve 8. There is a conduit 81 leading from the annular dish-shaped member 88 and chamber 84 to a closed cylindrical container 88 which contains a volatile liquid and is operable as a heat motor. There is an electric heating coil 89 positioned around the container 88 which is supplied with current from a power source 18 and controlled by a thermostat II (shown diagrammatically) In this form of the invention the operation is very similar to those heretofore described:

The electric heating coil 89 is normally energized and heat supplied to the container 88 to cause the volatile liquid therewithin to vaporize and supply pressure to the chamber 84. The expansion of the chamber 84 by the pressure of vapor therein will cause the diaphragm 8| to be compressed against the inner face of the cover member 82 thus causing a minimum volume for the chamber 88. The thermostat II is positioned in the path of air circulating over the evaporator I and is operable upon decrease of temperature of said circulating air to a predetermined value to de-energize the electric heating coil 88 thus permitting the volatile liquid in the container 88 to cool and condense thereby decreasing the pressure in the chamber 84 permittin the diaphragm 8| to move to a position against the inner face of the annular dish-shaped member 88. This operation of the member l9 as described perform the same function as the members I! in the other forms of the invention heretofore described in that a predetermined increase in volume of the expansible chamber 83 will cause a predetermined decrease in the maximum operating pressure of the expansion valve 8 causing the same to throttle flow of refrigerant to the evaporator I and thu increase the rate of dehumidification of the air circulating thereover.

In the form of the invention shown in Fig. 5 the expansion valve 8 is shown diagrammatically and the control member H is shown in sectional .view to illustrate the operation thereof. The control member I9 comprises a body member I2 having an enlarged cylindrical end portion 13 and a smaller cylindrical portion 14. The smaller cylindrical end portion 14 has an end wall member I5 which is connected by a conduit I8 to the expansion valve 8 operable to control the effective volume containing th thermostatic liquid from the thermostatic bulb 2 I. There is a flexible hollow bellows II sealed to the end wall 15 of the member l9 and operable to form an expansive and contractible chamber for controlling the maximum operating pressure of the expansion valve 8. In the large cyclindrical portion 18 there is larger bellows I8 which is sealed to the end wall member I8 which has a conduit 88 opening thereinto. The bellows I8 is urged toward a compressed position by a spring 8| and has a thrust rod 82 operatively interconnecting the bellows I8 and II. Th conduit 88 is connected to a thermostat 83 (shown diagrammatically) which is in turn connected by a conduit 84 to a source of pneumatic pressure 85. This form of the invention operates almost identically with that shown in Fig. 1, the only difference being that the pressure of the bellows I8 is supplied from a pneumatic pressure source 85 and controlled by a pneumatic thermostat 83 instead of a bulb element 48 as shown in Fig. 1.

As in the other forms of the invention th thermostat83 is operable upon the temperature of circulating air being cooled to a predetermined value to permit pressure within the bellows 18 to exhaust and the spring 8| to push the same toward collapsed position thereby expanding the bellows II and permitting the volatile liquid in the expansion bulb 2| to enter the gas phase thereby to decrease the maximum operating pressure of the expansion valve 8.

In the form of the invention shown in Fig. 6 the control member 9 has been altered as to make it manually adjustable. In this form of the invention as that shown in Fig. 4there is a T connection 88 joining the conduit 28 from the thermostatic bulb element 2|, the conduit l8 leading to the expansion valve 8 and the conduit 85 leading from the control member 8. The conduit 85 leads to a sealed flexible bellows 88 which is closed at both ends and is operable to vary the volume enclosing the thermostatic liquid from the bulb element II. The bellows 80 has a spring 81 therein which adjusts the same towards normal expanded position. The control member l8 has a main body member or casing "which encloses the bellows 86 and which has an adjustment screw 89 extending thereinto. The adjustment screw 89 is operable upon movement to expand or contract the bellows 86 thereby to perform the desired adjustment of maximum operating pressure which was accomplished in the other forms of the invention by automatic means.

It should be noted that the maximum operating pressure referred to throughout the speciflcation is well known to the art'being the maximum suction pressure of the evaporator I at which the valve 6 will open. This maximum operating pressure can also be expressed as the pressure within the bulb element 2! when the volatile liquid therewithin has entirely entered the gas phase less the pressure equivalent of the superheat setting of the valve. It should be further noted that although some forms of this invention are shown to use flexible bellows and others to use flexible diaphragms any suitable pressure responsive member or equivalent thereof could be substituted to perform the same function herein. It should also be noted that when the aforementioned maximum operating pressure is decreased by.a predetermined amount so that all of the liquid in the bulb or power element enters the gas phase the valve will at that point have changed from a thermostatic action to an -automatic" or pressure responsive action since the bulb or power element can no longer respond to the evaporator temperature.

system operable to supply gaseous pressure for moving said pressure responsive member; said thermostatic liquid being of a predetermined quantity such that the same may be completely vaporized within the range of normal operating temperatures of said valve, the pressure and temperature at which said thermostatic liquid is completely vaporized being determined by the amount of liquid present and the volume of said pressure system; a movable wall member in said pressure system for varying the volume thereof, and means to move said movable wall member to vary the volume of said pressure system thereby to vary the temperature and pressure at which said thermostatic liquid will be completely vaporized.

2. A refrigeration expansion valve comprising a movable valve member, a pressure responsive member operatively connected to said valve member and operable to move the same, a wall member enclosing a space above said pressure responsive member, a bulb element operable to contain a thermostatic liquid for supplying gaseous pressure to said pressure responsive member, a conduit interconnecting said bulb element and said enclosed space; said enclosed space, said conduit, and said bulb element forming an enclosed 8 4 same may\be completely vaporized within the range of normal operating temperatures of said valve, the pressure and temperature at which said thermostatic liquid is completely vaporized being determined by the amount of liquid present 1 and the volume of said pressure system, means forming an expansible and contractable chamber communicable with said enclosed pressure system, means operable to expand and contract said chamber to vary the volume of said pressure system, and said last named variations in pressure system volume being operable to vary the temperature and pressure at which said thermostatic liquid will be completely vaporized.

3. A refrigeration expansion valve comprising a movable valve member, a pressure responsive member operatively connected to said valve member and operable to move the same, a wall member enclosing a space above said pressure responsive member, a bulb element operable to contain a thermostatic liquid for supplying gaseous pres-- sure system operable to control said pressure repressure system operable to control said pressure sponsive member, said thermostatic liquid being of a predetermined quantity such that the same may be completely-vaporized within the range of normal operating temperatures of said valve, the pressure and temperature at which said thermostatic liquid is completely vaporized being determined by the amount of liquid present and the volume of said pressure system, means forming an expansible and contractable chamber communicable with said enclosed pressure system, thermostatic means operable to expand and contract said chamber to vary the volume of said pressure system, and said last named variations in pressure system volume being operable to vary the temperature and pressure at which said thermostatic liquid will be completely vaporized.

4. A refrigeration expansion valve comprising a movable valve member, a pressure responsive member operatively connected to said valve member and operable to move the same, a wall member enclosing a space above said pressure responsive member, a bulb element operable to contain a thermostatic liquid for supplying gaseous pressure to said pressure responsive member, a conduit interconnecting said bulb element and said enclosed space; said enclosed space, said conduit, and said bulb element forming an enclosed pressure system operable to control said pressure responsive member, said thermostatic liquid being. of a predetermined quantity such that the same may be-completely vaporized within the range of normal operating temperatures of said valve, the pressure and temperature at which said thermostatic liquid is completely vaporized being determined by the amount of liquid present and the volume of said pressure system, means forming an expansible and contractable chamber communicable with said enclosed pressure system, a heat motor operable to expand said chamber thereby to provide a predetermined increase in volume of said enclosed pressure sysstem, an electric heating coil for said heat motor, a thermostat for controlling energization of said heating coil, and said predetermined increase in volume being operable to reduce by a predetermined amount the temperature a d pressure at which said thermostatic liquid will be completely vaporized.

5. An air conditioning system comprising a refrigerant evaporator for removing heat from air circulating within an enclosure; an expansion valve for controlling flow of refrigerant to said evaporator, said expansion valve comprising a valve member, a pressure responsive member operatively connected to said valve member and operable to move the same, a cover member forming with said pressure responsive member an enclosed space, a bulb element communicable with said enclosed space and operable to contain a thermostatic liquid for supplying gaseous pressure thereto, said thermostatic liquid being of a quantity capable of being contained entirely within said enclosed space, means forming an expansible and contractable chamber communicable with said enclosed space and operable upon a predetermined expansion to provide a predetermined increase in the effective volume of said enclosed space thereby to decrease by a predetermined amount the maximum operating pressure of said valve, means cooperable with and operable to expand said chamber, and said predetermined decrease in maximum operating pressure being operable to cause said valve member to throttle fiow of refrigerant to said evaporator thereby decreasing the temperature of a portion of said evaporator to a point below the dew point of water vapor in said circulating air for more efficient dehumidification.

6. An air conditioning system comprising a refrigerant evaporator for removing heat from air circulating within an enclosure; an expansion valve for controlling flow of refrigerant to said evaporator, said expansion valve comprising a valve member, a pressure responsive member operatively connected to said valve member and operable to move the same, a cover member forming with said pressure responsive member an enclosed space, a bulb element communicable with said enclosed space and operable to contain a thermostatic liquid for supplying gaseous pressure thereto, said thermostatic liquid being of a quantity capable of being contained entirely within said enclosed space, means forming an expansible and contractable chamber communicable with said enclosed space and operable upon a predetermined expansion to provide a predetermined increase in the efiective volume of said enclosed space thereby to decrease bya predetermined amount the maximum operating pressure of said valve, thermostatic means positioned in the path of said circulating air and responsive to the temperature thereof, said thermostatic means being cooperable with said chamber and operable upon cooling of said circulating air to a predetermined temperature to cause said predetermined expansion of said chamber, and said predetermined decreasein maximum operating pressure being operable to cause said valve member to throttle flow of refrigerant to said evaporator thereby decreasing the temperature of a portion of said evaporator to a point below the dew point of water vapor in said circulating air for more efficient dehumidiflcation.

7. A refrigeration expansion valve comprising a movable valve member, a pressure responsive member operatively connected to said valve member and operable to move the same, a wall member cooperable with said pressure responsive member to form an enclosed space, a bulb element operable to contain a thermostatic liquid for supplying gaseous pressure to said pressure responsive member, a casing member having a passageway therethrough and an aperture communicable with said passageway, a conduit interconnecting said bulb element and one end of said passageway, a second conduit interconnecting the other end of said passageway and said enclosed space, a movable wall member closing said casing aperture and forming an expansible and contractable chamber communicable with said passageway, and means cooperable with said movable wall member to expand and to contract said chamber.

8. A refrigeration expansion valve comprising a movable valve member, a pressure responsive member operatively connected to said valve member and operable to move the same, a wall member cooperable with said pressure responsive member to form an enclosed space, a bulb element operable to contain a thermostatic liquid for supplying gaseous pressure to said pressure responsive member, a conduit interconnecting said bulb element and said enclosed 'space, a casing member having an aperture thereinto, a movable wall member cooperable with and closing said aperture and operable to enclose an expansible and contractable chamber, means interconnecting said chamber and said enclosed space, and means cooperable with said movable wall member operable to expand and to contract said chamber.

' FRANEYN Y. GAR'I'ER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PA'I'EN'I'S Number Name Date 2,199,498 Kaufman May 7, 1940 2,227,760 Newcum Jan. 7, 1941 2,242,334 Wile May 20, 1941 2,297,872 Carter Oct. 6, 1942 2,319,993 Kaufman May 25, 1943 2,475,558 Seligman July 5, 1949