US2038198A - Automatic control for refrigerating apparatus - Google Patents

Description

April 21, 1936'. J REPLQGLE 2,038,198

' AUTOMATIC CONTROL FOR REFRIGERATING APPARATUS Filed Aug. 22, 1927 2 Sheets-Sheet 1 Z4 y M91214!- April 21, 1936- J. R; REPLOGLE 2,038,198

AUTOMATIC CONTROL FOR REFRIGERATING APPARATUS Filed Aug. 22-, 1 927 2 Sheets-Sheet 2 a fi rs fl'.

l nvenwr 707711 I? Fep/oy/e.

Patented Apr. 21, 1936 I v UNITED STATES PATENT-OFFICE.-

AUTOMATIC common non REFRIGER- ATING APPARATUS John R. Replogle, Detroit, Mich., assignor to Kelvinator Corporation, Detroit, ltIich., a corporation of Michigan Application August 22, 1927, Serial No. 214,559

15 Claims. (01. 62-3) The present invention relates to refrigerating system co po at y invention associated system of the type having a high pressure side, wi h a r f ing pp r including a. heat dissipator such as a compressor Fig. 2 is a vertical, sectional view through the and condenser, and havi a l pressure id i refrigerant control structure taken substantially cluding a plurality of evaporators. on line 2-2 in Fig. 1; 5

One of the objects of the present invention is to 3 is a p Sectional w ila to provide a refrigerating system and control there- 2, showing the valve and actuating mech n in for in which refrigerant is not withdrawn from p Po t one of the evaporators until the predetermined 4 is a detailed, pe spective view of the sevdesired high temperature of the evaporator is eral elements comprising the V lv actuating 10 attained although the heat dissipating device is mechanism;

operating to withdraw refrigerant from one or Fig- 5 is a nta s t nal vi w tak n n more of the evaporators of the system. e 5-5 of Fig. 2.

Another object of the present invention is to T e mechanical refrigerating apparatus hereprovide a refrigerating system and control therein described is associated with a plurality 0f 15 for in which the flow ofrefrigerant from one of Chambers B and in'which is desirable the evaporators automatically stops after the premaintain difiel'ent predetermined ranges of tom-- determined desired low temperature of the evapperatures by means of evaporators D of the floodorator is attained although the heat dissipating ed type. The refrigerating apparatus includes a device is operative to withdraw refrigerant from heat dissipating device herein shown aspa comone or more of the other evaporators of the syspressor-condenser unit 10, the compressor portc 111. tion of which is driven by means of a power ap- More specifically it is an object of the invention pliance, such as an electric motor M. A common to p de a valve in the refrigerating line'leadsectional refrigerant feed conduit ll leads from ing from an evaporator to the heat dissipating the condenser to the evaporator D in chamber A, 25 device, which valve will remain closed, to prevent and acommon sectional refrigerant return suction the flow of refrigerant from said evaporator to conduit. l2 extends from the evaporator D in the heat dissipating device until a predetermined c ambe A to the p Branch feed 6011- high temperature is attained in said evaporator, duits l3 connect the common feed conduit II with although the device is operating to withdraw rethe evapo in chambers B and d branch 30 frigerant from another or other evaporators of conduits l4 connect the evaporators D in chamthe system and which valve will close although the bers B and C with the common return conduit heat dissipating device is operating to withdraw I2. I A pr ssu controlled sw h mechanism refrigerant from another or :other evaporators of responsive to the Pressure of the refrigerant the system. In carrying out the above objects, in the common return conduit I2 through the 3;, a snap acting valve is placed in the refrigerating onduit controls h operation of t powe line leading from the evaporator to the heat disappliance. 0f the refrigerating pp a sipating device and is responsive to pressure in is *i to start stop Power this line and is arranged to open when a predeappliance when a maxlmum and a mlmmum 40 termined high pressure is attained in the evappressure are respectively reached in the return 40 orator and will not close until a predetermined cnduiti the 9410mm m member A being in open communication with the refrigerant low pressure is attained in the evaporator.

A further object of the present invention is to return suctmn condmt' FY ET provide a system and control therefor in which the condenser to the con r0 amsm an s arranged to operate mechanism to open the 45 the pressure or temperature differential between switch when a predetermined excessive pressure the evaporator-s is positively limited to a certain is present in the condenser The switch opera, Vaiileing mechanism for automatically controlling the These and other obJects of the invention will motor operation by predetermined pressure in the pp more fully in the following detailed high and low side of the system is fully described scriptio taken in connection with the 3600111- in my co-pending application for Letters Patent, panying drawings which illustrate a preferred Serial No. 475,344 filed June 6, 1921, now Patent embodiment of the invention No. 1,823,002 granted September 15, 1931.

In the drawings: Assuming that it is desirable to maintain maxi- Fig. l is a diagrammatic view of a refrigerating mum temperatures of 15 F., 30 F., and 45 F. in 55 range in the chambers B and 0" different predetermined pressures must be maintained within the evaporators associated with said chambers. This is accomplished by providing a refrigerant control mechanism disposed between the evapcrators in chambers B and C and the return suction line for preventing the discharge of the expanded refrigerant from the said evaporators into the return conduit until a pressure is reached. I

Each control mechanism is composed of an automatically closing valve mechanism which is moved to open position after a predetermined pressure is attained withinthe evaporator associated therewith. A valve housing T connects each of the branch conduits H with the return conduit I2, and comprises a casing 20, preferably a casting having an interior chamber 2| and provided with an inlet. port 22 into which the branch conduit |4 extends. An outlet port 23 is provided in thecasing wall to connect the chamber 2| with a passage 24 extending across the lower portion of the casting and connected to form a part of the return conduit l2, suitable leak proof fittings 25 being'provided for such connections.

The valve mechahism is associated with th casting T and is arranged to open and close the outlet port 23. A metal bellows is secured at its lower end to a boss IS on the upper portion of the casting 20, the upper end of the bellows being secured to an end-p1ate26 through which the reduced end portion 21 of the rod 28 extends, the enlarged end of this extends interiorly of the chamber-2| and is connected with the motion multiplying portion of the mechanism. The upper reduced end of the rod extends through the opening 29 in the dome-shaped casing 30 surrounding the bellows, and an'adjustable nut 3| is screwed into the opening 29 and provided with "the annular spring seat 32.

The reduced section of the rod projects through the nut 3| and is surrounded by the coil spring 33 which is arranged between the valve seat 32 and the nuts which are adjustably secured to the threaded end of the reduced section of the rod. The coil spring 34 extends around the rod section 21 and is arranged between the spring seat 32 and the end plate 26 of the bellows. It will be seen that the position of the nut 3| adjusts the tension of the coil spring 34 while the nuts 35 adjust the tension of the spring 33. It will be seen that the interior of the bellows is in communication with the interior of the adjacent evaporator through the conduit M which opens into the chamber 2| and an opening I! in the casing through which the rod extends, so that refrigerant from-the evaporator will expand the bellows and move the rod attached thereto against the resistance of the springs 34.

The nut 3| is secured in adjusted position by the lock nut 8 which sciews on the threaded ex.-

terior thereof and into engagement with the easing 30. The tension of the spring 34 bearing against the bellows can be varied by adjustment of the nut 3|, so that by moving the nut toward the bellows the resistance to be overcome by refrigerant pressure before the valve mechanism is .evaporator at a desired high pressure.

away from the bellows the refrigerant pressure required to move the valve mechanism to open position is decreased. As the refrigerant pres-' sure in the evaporators D are in definite relation to the temperature exteriorly of the evaporators, the high temperature in the chambers can be automatically controlled by adjustment of the nut to permit the refrigerant to escape from the The spring 33 is shorter than the spring 34 so that when the valve mechanism is in open position the spring 33 exerts no tension against the nuts 35, but as the valve mechanism moves to closed position the spring 33 is compressed by the nuts 35 and retards the normal closing effect of the spring 34. This retarding effect by the spring 33 upon the closing movement of the valve mechanism determines the pressure in the bellows at which the valve closes so that by adjusting the nuts 35 toward or-away from the sylphon the pressure range of the refrigerant in the evaporator can be respectively increased or decreased,'

causing a relative variable range in the temperature adjacent the evaporator.

The mechanism for actuating the valve which is connected to the rod 28 multiplies the motion of the rod and moves with a snap action. In Fig. 2 the mechanism is in position closing the valve while Fig. 3 the mechanism is in a position opening the valve. The valve when closed positively prevents any of the refrigerant within the chamber 2| from leaking through the outlet port 23 into the passage 24 through the casing 29 which forms apart of the common return line. As the temperature within the chamber, associated with an evaporator which is in communication with the chamber 2|, increases, the pressure within the evaporator is relatively increased, this increased refrigerant pressure expands the bellows and moves the valve rod upwardly. The lower end of this rod is pivoted to a lever member 40 having one end provided with' arms 4| to which are secured the coil springs 42. The springs are also secured to a bell crank 43 which is in turn attached to the valve member 44 which engages the valve seat 45 at the mouth of the outlet port 23. The valve member is provided with a recess in which a coil spring 10 is seated, the spring bearing against an end of the member 43 which is pivotally secured to the valve member by the pin 1 I. As the rod 28 moves upwardly it rocks the member 40 which is pivoted to the bracket 46 by means of the pin 41, this bracket being rigidly secured to a wall of the casing 20 by means of the screws or other fastening devices 48. Supported on the pin 41 adjacent to the member 40 is a cam member 49 which is provided with the punched out lug 5|! which engages within the forked end 5| of the member 40. Movement of the member 40 will move the cam 49 which is also pivoted to the pin 41. The cam 49 is arranged to engage the arm 52, the beveled edge 53 of the cam engaging the ear 54 of the arm as the cam moves in the direction, as shown by the arrow in Fig. 2. The arm also provided with an ear 55which engages in either one of the notches 53 or 57 in the bell crank .43 which is pivotally supported on the pin 41. The arm. 52 is pivotally mounted upon the pin l which is secured to the bracket 46,.and a spring member 1 normally exerts upward pressure against the arm 52, the spring extending around the pin 1 atone end and being anchored against the bracket 46. The ear 55 is shown en gaged in the notch 56 in Fig. 2 and as the cam operated to open is increased and when moved 49 passes over the car 54 it will depress the arm 52 and move the ear 55 out of engagement with the notch 58. As the member 40 is rocked on itsv pivot the upper spring 42 will be stressed and placed under tension so that when the ear 55 of the arm is disengaged from the notch 51 the spring will exert a force on the bell crank 43 attached to the valve and rock the bell crank on its pivot in a clock-wise direction as viewed in Fig. 2,'thus moving the valve away from its seat and opening the outlet port 23.

It will be seen that the valve operating mechanism moves with a snap action as one of the springs 42 will so effect the member 43 when the lever 40 passes dead center in either direction. The ear 55, when the valve is opened, will be moved into thenotch 51 of the bell crank by the spring 1, and the valve actuating mechanism will be positioned as shown in Fig. 3 with the valve held open. The refrigerant, which is thus allowed to flow into the return conduit may or may not sufilciently increase the pressure in the return conduit to trip the pressure controlmechanism S-which is in communication with the return conduit to start the power appliance. -As the vaporized refrigerant is discharged from the e aporator through the chamber 2| and the port 23 into the return conduit the pressure of the refrigerant in the evaporator is reduced, this-reduced pressure permitting the bellows to contract thus moving the valve rod downwardly and moving the member 40 in a. counter clock-wise direc- I tion and rocking the cam 49 in a direction as indicated by the arrow in Fig. 3. The beveled edge 50 of the cam now engages the ear 54 and depresses the arm 52 to disengage the ear 55 from the notch 51 of the bell crank. The movement of the member 40 will reduce the tension in the upper spring 42 and increase the tension of the lower-spring 42 so that when the ear 55 is disengaged from the notch 5'! the tension of the lower [spring will cause the valveto snap shut after the member 40 passes dead center and instantaneously close the port 23.

It will thus be seen that the mechanism I have provided is positive in its action, operates instantaneously when a certain predetermined pressure is reached in the evaporator associated therewith, and as a result of this positive valve action the flow of the vaporized refrigerant fromthe evaporator into the return conduit is controlled in such a manner as to positively prevent the discharge of said-vaporized refrigerant into the return conduit until a definite predetermined maximum'temperature is reached in the chamrefrigerant in said evaporator. With the mechanism described the valve can be adjusted to be opened at a predetermined pressure, and can be adjusted to close at a predetermined lower pres- "sure than the opening pressure, thus permitting 'a temperature range in the chambers to be cooled.

Thus it is apparent that I have provided a mule vtiple refrigerating system including a single heat dissipating device operatively associated with a plurality of evaporators in which the temperature of each evaporator may be controlled and maintained entirely independent of another or others in the system. All evaporators may be maintained between the same maximum temperatures or each may be maintained between different ranges of temperature than all the others. The

withdrawal of gaseous refrigerant from one evapincreased to its predetermined maximum temperature. Also, the lowering of the temperature of an evaporator, demanding withdrawal of gaseous refrigerant, will continue until its temperature is decreased to the desired predetermined minimum at which time, the evaporator will be shut off from the heat dissipating device, even though the heat dissipating device is operating to withdraw gaseous refrigerant from another evaporator, and will remain shut off until the predetermined maximum high temperature is attained. Furthermore, by positively preventing the escape of gaseous refrigerant from an evaporator until 'itsdesired maximum high temperature is attained, gaseous refrigerant cannot pass to and condense in and disturb the temperature of another evaporator. It'will thus be seen that when the evaporators are to be operated at different temperatures, the snap acting valve prevents the lowering of pressure on the higher temperature evaporator and thereby positively prevents the pressure diflerential between the evaporator from decreasing to less thanthe desired value, or it.

maybe said that the snap acting valve maintains the pressure differential between the evaporators above a certain desired value.

Although I have illustrated but one form of my invention and have described in detail but a single application thereof, it will be apparent to those skilled in the art that many minor modifications and changes may be made therein without departing from the spirit of my invention or from the scope of the appended claims.

What I claim is:

1. In an artificial refrigerating system for maintaining different maximum temperatures within a. plurality of chambers, having a single compressor-condenser unit and power appliance, a plurality of evaporators associated with said chambers and adapted to contain liquid refrigerant, and common refrigerant feed and return conduits for connecting said evaporators with the compressor-condenser unit, the combination therewith of means affected by the pressure within thereturn conduit to control the operation of the power appliance, and means affected by the pressure in one of the evaporators to positively prevent a premature discharge of refrigerant from said evaporator into the return conduit until a predetermined temperature is reached in the chamber associated with said evaporator.

2. In an artificial refrigerating system for maintaining definite maximum temperatures within a plurality of chambers having a single compressor-condenser unit and power appliance, a plurality of evaporators associated with said chambers and adapted to contain liquid refrigerant, a common refrigerant feed and return conduit for connecting said evaporators with the compressor-condenser unit, a combination therewith of means afl'ected by the pressure within the return conduit to control the operation of the power appliance, a valve for regulating the flow maximum or minimum pressure is reached in the evaporator.

3. In an artificial refrigerating system, the combination with a single compressor-condenser unit and power appliance, of a plurality of chambers, a plurality of evaporators each being associated with one of said chambers and adapted to contain liquid refrigerant, refrigerant feed and return conduits for connecting said evaporators with the compressor-condenser unit, means for controlling the operation of the power appliance, and means afiected by the pressure in one of the evaporators to positively prevent a premature discharge of the refrigerant from the said evaporator into the return conduit until a predetermined temperature is reached in the chamber associated with said evaporator.

4. In an artificial refrigerating system, the combination with a single compressor-condenser unit and power appliance, of a plurality of chambers, a plurality of evaporators each being associated with one of said chambers and adapted to containJiquid refrigerant, refrigerant feed and return conduits for connecting said evaporators with the compressor-condenser unit, means for controlling the operation of the power appliance, a valve for regulating the flow of the refrigerant from one of the evaporators into the return conduit, means responsive to the pressure internally of said evaporator for actuating said valve and including a snap action valve control for maintaining said valve in either its closed or open position until a predetermined maximum or minimum pressure is reached in the said evaporator.

5. In an artificial refrigerating system; the combination with a heat dissipating device, of a plurality of evaporators operatively connected with the heat dissipating device; and means, affected by the pressure in one of the evaporators, to positively prevent a discharge of refrigerant from said evaporator until the pressure in the evaporator attains a certain value.

6. In an artificial refrigerating system; the combination with a heat dissipating device, of a plurality of evaporators operatively connected with the heat dissipating device; and means, affected by the pressure in one of the evaporators, for positively preventing the discharge of refrigerant from the evaporator after the pressure in the evaporator decreases to a predetermined minimum and until the pressure in the evaporator increases to a predetermined maximum.

7. In an' artificial refrigerating system; the combination with a heat dissipating device, of a plurality of evaporators operatively connected with the heat dissipating device; and means, affected by the pressure in one of the evaporators and operable after the temperature of said evaporator has attained a predetermined maximum, for positively maintaining the evaporator connected with the heat dissipating device until the temperature of the evaporator decreases to a predetermined minimlim and for positively preventing a discharge of refrigerant from the said evaporator to the device until the pressure of the evaporator increases to a predetermined maximum.

8. In an artificial refrigerating system; the combination with a heat dissipating device, of a plurality of evaporators operatively connected with the heat dissipating device; a valve for controlling the flow of refrigerant from one of said evaporators; mechanism for positively maintaining said valve closed while the temperature,

of the said evaporator increases from a predetermined minimum temperature to a predetermined maximum temperature; and means, affected by a predetermined maximum pressure in the said evaporator, for opening said valve.

9. In an artificial refrigerating system; the combination with a heat dissipating device, of a plurality of evaporators; means operatively connecting the evaporators with the heat dissipating device; a valve for controlling the flow of refrigerant from one of said evaporators, said valve having a wide open position and a positively closed position; and means, affected by a predetermined pressure in the said evaporator, for causing said valve to move with a snap action from one of said positions to the other position.

10. In an artificial refrigerating system; the combination with a heat dissipating device, of a plurality of evaporators; means operatively connecting the evaporators with the heat dissipating device; a valve for controlling the fiowof refrigerant from one of said evaporators, said valve having a wide open position and a positively closed position; and means, affected by a predetermined maximum pressure in the said evaporator, for causing said valve to move with a snap action from the closed position to the open position.

11. In an artificial refrigerating system; the

combination with a heat dissipating device, of a plurality of evaporators; means operatively connecting the evaporators with the heat dissipating device; a valve for controlling the flow of refrigerant from one of said evaporators, said valve having a wide open position and a positively closed position; and means, affected by a predetermined minimum pressure in the said evaporator, for causing said valve to move with a snap action from the open position to the closed position.

12. In an artificial refrigerating system; the combination with a heat dissipating device, of a plurality of evaporators; means operatively connecting the evaporators with the heat dissipating device; a valve for controlling the fiow of refrigerant from one of said'evaporators, said valve having a wide open position and a positively closed position; and means, affected by a predetermined maximum pressure in the said evaporator, for causing said valve to move with a snap action from the closed position to the open position and, affected by a predetermined minimum pressure in the said-evaporator, for causing said valve to move with a snap action from the open position to the closed position.

13. 'A refrigerating system comprising, in combination; a low pressure side including a plurality of evaporators; a refrigerant circulating unit operatively connected with said evaporators for delivering liquid refrigerant to and formducing the pressures insaid evaporators; means, responsive to changes in conditions in said system, for controlling the operation of said refrigerant circulating unit; and refrigerant flow control means, influenced by pressure conditions in said low pressure side, to positively limit the pressure reduction in one of said evaporators relative to the pressure reduction in the other.

14. An artificial refrigerating system comprising, in combination; a high pressure side including a heat dssipator, and a low pressure side including a low temperature evaporator and a high temperature evaporator, said evaporators being operatively connected with the high pressure side; and means for maintaining a temper ture difierential between said evaporators while heat is being dissipated in the high pressure side,

said means being influenced by pressure in the low pressure side of the system for positively maintaining the pressure differential between the evaporators above a certain desired value.

15. An artificial refrigerating-system comprising, in combination; a high pressure side including a heat dissipator, and a low pressure side including a low temperature evaporator and a- 10 high temperature evaporator, said evaporatorsbeing operativeiy connected with the high preswhile heat is being dissipated in the high pres-' sure side, said means being influenced by pressure in the low pressure side of the system for positively preventing the pressure diflerential between theevaporators from decreasing to less than a certain desired value.

JOHN R. REPLOGLEQ

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