US1978469A - Refrigerating system - Google Patents

Description

Oct. 30, 1934. J. MARINGER HEFRIGERATING SYSTEM 2' Sheets$heet 1 Filed Jan. 11, 1-952 Oct. 30, 1934.

L. J. MARINGER 1,978,469

REFRIGERATING SYSTEM Filed Jan. 11, 1932 Y 2 Sheets-Sheet 2 Patented Oct. 30, 1934 PATENT OFFICE REFRIGERATING SYSTEM Lawrence J. Maringer, Buffalo, N. Y., assignor to R. G. Wright & Company, Buffalo, N. Y.

Application January 11, 1932, Serial No. 585,870

15 Claims.

This invention relates to refrigerating systems in which an accurate temperature control of the medium which is being cooled is desired.

The objects of this invention are to provide 6 a refrigerating system, by means of which the temperature of the medium whichis being cooled can be automatically and accurately controlled; also to provide a refrigerating system in which the evaporator is fully flooded with liquid refrigerant, and in which liquid refrigerant is supplied to the evaporator only at times during which the level of the liquid circulated in the evaporator drops below a predetermined point, and when at the same time increased refrigeration is desired; also to provide a refrigerating system of this kind including a thermo-responsive member acted upon by the medium which is being,

cooled and through, which communication is established between the evaporator and the compressor when refrigeration is required, to withdraw vapor from the evaporator to the compressor and to supply liquid refrigerant to the evaporator; also to provide a system of this kind provided with means for automatically operating a refrigerating system of this kind under all conditions; also to provide a system of this kind adapted for cooling of fluids in which refrigeration is interrupted whenever the flow of fluid being cooled is interrupted; also to provide a system of this kind with a safety or blow off valve, by means of which vapor may be discharged from the evaporator if the vapor pressure becomes excessive; also to improve refrigeration systems in other respects hereinafter specified. In the accompanying drawings, the refrigeration system embodying this invention is disclosed as employed in connection with the cooling of a liquid, such for example as milk by circulating the same in contact with the outer wall of a part of an evaporator, but it will be understood that it is not intended to limit this invention to use in connection with cooling liquids, since, obviously, the inventon can be employed for producing refrigeration in any liquid, solid, or gaseous medium. In the accompanying drawings:

Fig. 1 is a side elevation, partly broken away, of a liquid cooling apparatus having a part of a refrigerating system embodying this invention 53 applied thereto;

Fig. 2 is an enlarged central sectional elevation of a supply tank or container for use in connection with the circulation of liquid refrigerant in the evaporator;

Fig. 3 is a fragmentary elevation on a still larger scale, showing a float controlled switch for use in connection with the controlling of the supply of liquid refrigerant to the container;

Fig. 4 is a diagrammatic view of the refrigerating system and electrical connections for con- 80 trolling the same.

Fig. 1 shows a cooling apparatus in which warm liquid may enter through a tube 7 and pass through a series of tubes 8 which are partly surrounded by larger tubes 9 to which suitable preliminary cooling liquid, such as water, may enter through a pipe or duct 10, and 11 represents a discharge duct for this cooling medium. This portion of the apparatus may or may not be used in connection with my refrigerating system and serves merely to effect preliminary cooling of the liquid by means of cold water; a final cooling being effected by a refrigerant in accordance with my improved system.

The liquid leaves the preliminary cooling apparatus through a pipe 12 and enters into a pipe 14 from which it flows through a number of similar pipes or ducts 15 which are also partly surrounded by larger pipes 16 containing the refrigerant. 17 represents the discharge pipe through which the cooled liquid is discharged, flow of liquid through the pipe 1'7 being controlled by means of a valve 18 having a handle 19. 20 represents a base for the apparatus including legs 21 for supporting the same from the floor.

Liquid refrigerant of any suitable kind such, for example, as ammonia, may be used in connection with my refrigerating system in such a manner that the liquid refrigerant is circulated in an evaporator, such for example as the pipes 16, in contact with the medium to be cooled, which, in the particular case illustrated, is passed through the pipes 14 and 15 conducting the liquid to be cooled, and means are provided for collecting the vaporized refrigerant from pipes 16. An evaporator of any other suitable or desired form may be provided and the evaporator itself may be provided with a space in which vaporized refrigerant may collect or a container connected with the evaporator may be employed. In the construction shown, a container or reservoir 24 is provided which may be connected with the evaporator in any suitable manner to provide for a circulation of the liquid refrigerant. in the evaporator and for the collection of vaporized refrigerant. In the construction shown, the container 24 has two pipes 25 and 26 connecting with the evaporator, but it will be understood that as many pipes or connections with the evaporator may be employed as may be desired. In order to produce a thermmsiphon circulation, the pipes 16 are inclined as shown in Fig. 1, so that the refrigerant, as it becomes warmed by contact with the pipes 14 and 15, may flow upwardly toward the pipe connecting with the container 24. The inclination of the pipes 16 also causes gas or vapor formed in the evaporator to flow upwardly toward the container 24.

The upper portion of the container 24, as is clearly shown in Fig. 2, is arranged to receive vaporized refrigerant, and baflles 28 of any suitable construction may be employed in this portion of the refrigerant container 24 to eliminate or separate liquid refrigerant from vaporized refrigerant when the latter is withdrawn from the container 24 through the pipe or duct 29. Within the container 24 is also provided a float chamber 30, in which a float 31 is mounted on one end of an arm 32, the other end of which is pivoted at 33 and has a mercury switchv 34 mounted thereon, the switch being arranged so that when the float arm is in the lower position indicated in Fig. 3, the switch will be closed, owing to mercury flowing into contact with both terminals of the switch which extend into the container for the mercury. These terminals are connected to conductors 35 and 36 which extendout of the refrigerant container 24. 3'7 is a stop against which the float or float arm may rest when in its lower position in which contact is made through the mercury switch 34. The float chamber may be separatedfrom the interior of the container 24 by means of a perforate housing 38, so that agitation of the liquid refrigerant in the container 24 will not change the position of the float.

40 represents an inlet pipe for admitting the liquid refrigerant to the container 24. The flow of refrigerant through the pipe 40 is controlled by means of a valve 41, preferably actuated electrically, for example, by means of a solenoid 42, the valve being normally closed by a spring or other suitable means (not shown), and being opened when current passes through the solenoid 42. 43, Fig. 1, represents a filter or strainer for the liquid refrigerant in the pipe 40.

The discharge pipe 29 through which vaporized refrigerant is withdrawn. from the container 24 is also controlled by means of an electrically operated valve 46, which may be constructed similarly to the valve 41, and which is also normally closed by a spring or any other means. The pipe or duct 29 leads to the compressor for the refrigerant. Preferably, a safety valve of any suitable construction is also provided through which vaporized refrigerant may escape from the evaporator or container 24 when the pressure becomes excessive. A safety device 48 is shown in Fig. 1,.

which is connected by pipes 49 and 50 connecting i with the pipe 29, in such a manner as to bypass the electrically controlled valve 46. During the normal operation of the, apparatus, the safety valve 48 is closed so that no vapor escapes through the bypass pipes 49 and 50. 51 represents a separator or strainer in the. vapor discharge pipe 29,

which may also be of any suitable or desired construction, such as is commoply employed in vapor passages of refrigerating systems.

Referring now to Fig. .4, in which are shown diagrammatically the parts of the refrigerating system which are connected with the pipes 29 and 40, 54 represents a compressor, to the inlet passage of which the pipe 29 leads. The compressor subjects the vapor withdrawn from the pipe 29 to pressure and then discharges the same through a passage 55 to a condenser 56 of any usual or suitable construction, in which the compressed vapor is condensed into liquid form, and is then conducted to a storage reservoir 5'7. The pipe or duct 40 receives liquid refrigerant from the reservoir 57, as clearly shown in Fig. 4.

In the operation of the apparatus thus far described, it will be obvious that when both the valves 41 and 46 are closed and when the evaporator is exposed to a medium of a higher temperature than that of the refrigerant in the evaporator, vaporization of the refrigerant in theevaporator results and the pressure of refrigerant vapor within the container 24 rises rapidly, and at the same time. increases the temperature of the refrigerant, so that the evaporation andcorresponding refrigerating action is quickly reduced and ceases entirely when a certain pressure is attained within the container 24. If refrigeration is desired, the valve 46 is opened to permit vapor to be withdrawn from the container 24 by the compressor 54, and as soon as the vapor pressure in the container 24 is reduced, evaporation of liquid refrigerant takes place, resulting in cooling of the medium contacting with the evaporator. As the liquid refrigerant becomes evaporated, the liquid level within the container 24 will be reduced, causing the float to drop, and the valve 41 is then opened to admit liquid refrigerant to the container 24 until the desired liquid level has again been attained.

The actuation of the refrigerating system can be readily carried on automatically, and preferably the refrigeration is controlled by thermostatic means, such for example as a thermostatic member 60 of any suitable construction, which may be arranged to extend intothe medium which is being cooled. In the construction shown, this member extends into one of the tubes 15 which are arranged within the evaporator pipes 16. The thermostatic member 60 may contain an expansible gas, the pressure of which is communicated by a tube 61 to a switch device 62, which may be of any desired construction, serving to close a circuit when the temperature of the medium to which the thermostatic element 60 is exposed rises above a certain point. A switch of this kind is diagrammatically indicated in Fig.

4, in which a bellows 63 is provided which is acted upon by the expansible gas, and which in turn acts upon a lever 64 on which a mercury switch 65 may, for example, be mounted. In Fig.

4, the parts are shown in the position which they occupy when the medium acting on the thermostatic member 60 is at a temperature above that 180 desired, the bellows 63 being then extended to move the lever 64 into a position in which a circuit is closedby the mercury in the switch 65. This circuit is connected to one side of a line controlled by a switch 66, a conductor 6'! connecting with one terminal of the mercury switch 65, and a second conductor 68 being connected with the other terminal of the switch 65.

When the refrigerating system is applied to a liquid cooler, such for example as a milk cooler, the flow of milk or other liquid may be interrupted at times. For example, in milk coolers, it is customary to permit the milk to flow into a tank of a bottle filling machine and means are provided for shutting off the flow of milk from the cooler to the filling machine tank when the tank becomes filled. This may be done either by a hand operated valve, by means of a float operated valve in the tank of the bottle filling machine, or by both of these means. When the flow of liquid 150 through the pipes 14 and 15 which are acted upon by the refrigerant, is interrupted, the refrigerating action must also be interrupted, since otherwise the liquid might freeze or become excessive- 1y cooled in the pipes 14 and 15. For this purpose,

one or more switch or circuit breaking devices may be employed, which are so arranged as to break an electric circuit in which the electric means for opening the valves 41 and 46 are included. In the construction shown, a mercury switch '70 is provided for this purpose, and conductors 68 and '71 are connected to the two terminals of the switch 70. The switch 70 may be actuated in any suitable or desired manner so that it will be in open circuit position when the .flow of fuid through the cooler is interrupted by any means. For the purpose of illustrating one example as to how this switch may be operated, it is shown in Fig. 1 as connected with the movable part of the valve 18, and is shown in circuit closing position when the valve is open. It will be understood, however, that this switch may be operated by means of any device which either interrupts the flow of milk or other liquid through the cooler or which is acted upon by the flow of liquid to break the circuit through the switch when the flow is interrupted, and it will also be understood that two or more switches may be employed and arranged in series, for example, one switch may be actuated by the hand valve and another by a float controlled valve, not shown.

The conductor 71 connects with a conductor '72 leading to a solenoid 73 or other electric device for operating the valve 46, the other terminal of the electric device being connected with a conductor '74 with the other terminal of the control switch 66. Consequently, when the temperature of the liquid is above that desired, and when liquid is flowing through the pipes 14 and 15 of the cooler, as for example is the case when the valve 18 is open, current will flow through the solenoid or other electric device to open the valve 46, thus enabling the compressor to withdraw vapor from the container 24' through the pipe 29, reducing the pressure therein and causing refrigeration. When the temperature of the medium which is being cooled drops to a desired point, the thermostat causes the lever 64 to swing in a direction to open the circuit through the mercury switch 65, so that the valve 46 again becomes closed, which permits pressure to build up in the evaporator, causing refrigeration to be reduced and finally interrupted. Similarly, if the flow of liquidis interrupted, for example, when the handle 19 of the valve 18 is turned into a closed position, the mercury switch will be moved out of its horizontal position so that the circuit through this switch is broken, thus also causing the valve 46 to be closed.

The valve 41 is also controlled through the thermostat 60 and the valve 18, and furthermore, through the float 31, since, obviously, the valve 41 'should remain closed until the-liquid level within the container 24 drops to a point requiring more liquid refrigerant in the container. Consequently, the conductor 71 is connected to a branch conductor '75 leading to the solenoid or other electric actuating device 42, and the return circuit from the solenoid is completed through conductors 36 and 35 and through the mercury switch 34 of the float.- When the levelof the liquid in the container 24 is low, the 'float will occupy the position shown in Figs. 3 and 4, thus completing the circuit through the switch 34 and permitting the liquid supply valve 41 to be opened.

Any other electrical connections to accomplish the results described may be employed, or if desired, other means for effecting the automatic regulation of the system may be used in place of those shown.

The system described has been found to be very satisfactory for an accurate regulation and control of temperature. When the valves 41 and 46 are closed, refrigeration continues for a very brief interval of time during which enough refrlgerant is evaporated to raise the pressure within the evaporator to the point where further evaporation stops. In order to allow for the additional refrigeration which takes place during this interval of time, it is desirable to subject the thermostatic member 60 to the action of the liquid some time before it is discharged from the cooler and to have this thermostatic member set to operate at a temperature slightly above that ultimately desired. This is done in the construction illustrated by placing the thermostatic member 60 into the pipe above the lowest pipe l5 of the cooler, as shown in Fig. 1. In this way, a closer regulation of the temperature of the liquid discharged from the cooler can be obtained. The refrigerating system does not interfere with the cleaning of the pipes, through which the milk or other liquid passes, and even if these pipes are cleaned with hot water, no ill effects result, since the safety valve 48 will permit vapor to escape to the compressor if the pressure within the evaporator and container 24 becomes excessive.

I claim as my invention:

1. In a refrigerating system, the combination of an evaporator in contact with the medium to be cooled, supply means for maintaining said,

evaporator fully flooded with liquid refrigerant, thermo-sensitive means subjected to the temperature of said medium to be cooled, means controlled by said thermo-sensitive means to regulate the pressure in said evaporator for regulating the temperature of said medium to be cooled, and means also actuated by said thermo-responsive means for closing said supply means to prevent the supply of liquid refrigerant to said evaporator when said medium has been cooled to the desired temperature.

2. In a refrigerating system, the combination of an evaporator in contact with the medium to be cooled, means including a float for'maintaining said evaporator fully flooded with liquid refrigerant, thermo-sensitive means subjected to the temperature of said medium to be cooled, a valve controlling the discharge of vapor from said evaporator, and means actuated by said thermosensitive means for closing said valve when the temperature of sa d medium to be cooled is lowered to the desired degree, said thermo-responsivemeans in conjunction with said float acting to automatically prevent the supply of liquid refrigerant to said evaporator when said medium has been cooled to the desired temperature.

3. A refrigerating system for cooling a flowing fluid medium, including an evaporator against which said medium flows and in which liquid refrigerant is vaporized, a refrigerant control valve which is closed for confining refrigerant in said evaporator when further cooling is to be retarded, a valve controlling the flow of said fluid medium in contact with said evaporator, and means actuated by said second valve for closing said first mentioned valve upon movement of said second valve to closed position.

actuated by movement of said fluid control valve to closed position to break said circuit to close said refrigerant control valve.

5. A refrigerating system, including means for compressing and liquefying vaporized refrigerant, an evaporator in which liquid refrigerant is vaporized, means for maintaining a supply of liquid refrigerant in said evaporator including an electrically controlled valve through which liquid refrigerant may flow to said evaporator, said valve being normally closed, means for conducting vaporized refrigerant from said evaporator to said compressing and liquefying means and including an electrically operated valve which is normally closed, a thermostatic device subjected to the action'of a medium which is being cooled, an electric circuit for the electric operating means of each of said valves, a switch controlling the flow of electricity in each of said circuits, said switch being controlled by said thermostatic device and opened when said medium has been cooled to the desired extent, a float controlled switch in the circuit of the electric operating means of said first mentioned valve, said switch being closed only when the liquid refrigerant in said evaporator fallsbelow a predetermined level.

6. A refrigerating system for cooling a fluid medium, including an evaporator which contacts with said medium and in which a liquid refrigerant is vaporized, a valve controlling the flow of medium contacting with said evaporator, means for maintaining a supply of liquid refrigerant in said evaporator, means for withdrawing vaporized refrigerant from said evaporator including an electrically operated valve which is normally closed, a thermostatic device exposed to the temperature of said medium, a switch closed by said thermostatic device when the temperature of said medium is above that desired, a circuit including said switch and said electric means for operating said second valve, and a second switch in said circuit which is opened when said first mentioned valve is closed, to interrupt refrigeration, when said first mentioned valve is closed.

'7. A refrigerating system for cooling-a fluid medium, including an evaporator which contacts with said medium and in which a liquid refrigerant is vaporized, a valve controlling the flow of medium contacting with said evaporator, means for compressing and liquefying vaporized refrigerant, a connection between said last mentioned means and said evaporator for supplying liquid refrigerant to said evaporator, an electrically actuated liquid refrigerant, supply valve in said connection, said valve being normally closed when said electric means are inoperative, a connection through which vaporized refrigerant is withdrawn from said evaporator and supplied to said compressor, said last mentioned connection including an electrically operated valve which is normally closed when the electric operating means therefor are inoperative, an electric circuit for each electric valve operating means, a thermostatic device exposed-to the temperature of said medium, an electric switch closed by said thermostatic device when the temperature of said medium is above that desired, said switch controlling the supply of electricity to both of said circuits, a switch operated by said first mentioned valve and connected in series with said first mentioned switch and opened when said first mentioned valve is in closed position, a switch in the circuit of said liquid refrigerant supply valve, and means for moving said switch into circuit closing position when the level of liquid refrigerant in said evaporator falls below a predetermined point.

-8. A refrigerating system, including a compressor, an evaporator in-which liquid refrigerant may circulate, a container for liquid'refrigerant connected with said evaporator, the upper portion of said container forming a chamber for vapor, a valve controlled duct connecting the vapor chamber of said container with said compressor, a valve controlled duct for conducting liquid refrigerant to said container, means for causing the valve of said first mentioned duct to open and establish communication between said container and said compressor whenever refrigeration is desired, and said valve of said second duct being opened to admit refrigerant to said container only when the level of refrigerant in said container falls below a predetermined point and when refrigeration is desired, and means for closing the valves of both of said cuts when refrigeration is to be interrupted.

9. A refrigerating system, including an evaporator, a container for liquidrefrigerant closely connected with the evaporator to produce free circulation of the refrigerant in the evaporator and container, passages connecting said container with a compressor, one of said passages conducting vapor from said container to the compressor and the other passage being adapted to admit liquid refrigerant to said container, valves in said passages, thermostatic means for opening the valve in said vapor passage when more refrigeration is desired and also for opening the valvein said liquid passage when more refrigeration is desired and when the liquid in said container becomes lowered.

, 10. A refrigerating systemfor cooling flowing fluids, including an evaporator against which said fluid flows, a container for liquid refrigerant closely connected with the evaporator to produce free circulation of the refrigerant in the evaporator and container, passages connecting said container with a compressor, one of said passages conducting vapor from said container to the compressor and the other passage being adapted to admit liquid refrigerant to said container, means operable to close each of said passages, a valve for controlling the flow against said evaporator of fluids to be cooled, and means actuated by a fluid controlling movement of said valve for actuating said closing means for said passages for closing said passages to interrupt refrigeration.

11. A refrigerating system for cooling a fluid medium, including an evaporator which contacts with said medium and in which liquid refrigerant is vaporized, means for preventing further flow of refrigerant to said evaporator when further cooling of the fluid medium is to, be retarded, and means operable upon an appreciable interruption in the flow of said fluid medium and its consequent retention in contact with said. evaporator for actuating said refrigerant flow preventing means.

12. A refrigerating system for cooling a fluid medium, including an evaporator which contacts with said medium and in which liquid refrigerant is vaporized, a valve which is closed for preventing further flow of refrigerant to said evaporator when further cooling is to be retarded, and means for eifecting the closing of said valve, and which means are operable by and when a substantial interruption in the flow of said medium occurs.

13. A refrigerating system for cooling 9. fluid medium, including an evaporator which contacts with said medium and in which liquid refrigerant is vaporized, a valve which is closed for preventing further flow of refrigerant to said vaporizer, electric means including a circuit for opening said valve, and means for interrupting said circuit to close said valve when the flow of said fluid medium through said evaporator is substantially interrupted.

14. A refrigerating system for cooling a fluid medium including an evaporator through which a liquid refrigerant passes and is vaporized, means for conducting said fluid medium into contact with said evaporator, control means operable to allow the free flow of said medium or to interrupt the flow thereof relative to said evaporator, at will, means for checking the passage of refrigerant through said evaporator to retard cool 1g action upon said fluid medium, said check means being automatically operable upon actuation of said fluid control means to interrupt the flow of said fluid medium.

15. A refrigerating system for cooling a fluid medium including an evaporator through which a liquid refrigerant passes and is vaporized, a passage for conducting said fluid medium into intimate contact with said evaporator, means operable at will to close said passage and interrupt the flow of said fluid medium, a valve which, when closed, confines said refrigerant in said evaporator to retard the cooling action thereof, and

means interposed between said valve and said passage closing means and which is operable to close said valve upon operation of said last named means to closing position.

LAWRENCE J. MARINGER.

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