US2173082A - Refrigeration apparatus - Google Patents

Description

Sept. 12, 1939. KALISCHER 2,173,082

REFR IGERAT I ON APPARATUS Filed Sept. 27, 1935 eoonanonn WITNESSES INVENTOR MILTON KauscHER. f Q MA. BY U9 A TTOR EY Patented Sept. 12, 1939 UNITED STATES PATENT OFFICE REFRIGERATION APPARATUS Pennsylvania Application September 27, 1935, Serial No. 42,432

9 Claims.

My invention relates to water-cooled refrigerating systems and it has for an object to provide an improved system of this kind.

A further object of my invention is to provide an improved refrigerating system employing a single control device for initiating and terminating the flow of cooling water as the system is started and stopped and for maintaining the flow of cooling water at a substantially constant rate irrespective of the load or condenser pressure.

In the copending application of R. E. Holmes, Serial No. 37,668, filed August 24, 1935, and assigned to the assignee of the present application, there is disclosed and claimed a system of refrigeration in which the supply of cooling water for the condenser is maintained constant irrespective of condenser or head pressure so that the head pressure increases and decreases with increases and decreases in load. The supply of cooling water and the rate of flow thereof are controlled by separate devices; the former of which operates incidental to the starting and stopping of the machine.

I propose to provide a single device for initiating and terminating the supply of cooling water and for regulating the pressure or flow therethrough. Means are provided for actuating the device for initiating and terminating the supply of cooling water as the control device for the refrigerating machine is adjusted to its running and stop positions, respectively.

A further object of my invention is to provide an improved water cooled refrigerating system having a unitary device for controlling the supply and rate of flow of the cooling water, which may be constructed, inexpensively and without the necessity of tapping into refrigerant lines for controlling water flow.

These and other objects are effected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawing, forming a part of this application, in which:

The single figure is a diagrammatic view of a refrigerating system arranged in accordance with my invention.

The drawing shows my improved refrigerating system applied for cooling the air for an enclo- 50 sure indicated at III. A duct II conveys the air to the enclosure, within which duct an evaporator I2 and a fan I3 are disposed, the evaporator I2 cooling the air translated by the fan I3. The

evaporator I2, forming a part of my improved system, may be of any suitable type and may include a serpentine tube or coil H provided with a plurality of heat-absorbing fins I5.

Associated with the evaporator I2 are a watercooled condenser I6 and a refrigerating machine I1 shown by way of example as of the hermeticah 5 ly-sealed type. The latter includes a compressor I8 driven by an electric motor I9, both of which are enclosed by a casing 2|. Energization of the motor I9 is controlled by a switch 20, preferably of the quick make and break type. It is to be 10 understood that the particular form of the switch shown on the drawing is given merely as an example, and that any suitable form thereof, actuated either manually or by any suitable mutomatic mechanism known in the art, may be em- 16 ployed.

The casing 2I is preferably provided with a cooling coil 22 secured thereto in heat-exchanging relation. The heat of the motor I! and compressor II is conducted to the casing 2| and the 20 coil 22 and is absracted by water flowing in the coil 22 in a well known rrianner.

Refrigerant vapor is withdrawn from the evaporator I2 by the compressor I8 through a conduit 23 and is compressed and delivered at a rela- .tively high pressure by means of a conduit 24 to the condenser I6 as is well understood. The gas is cooled in the condenser I6 while under pressure and is condensed. Liquid refrigerant from the condenser passes through a conduit 25 and an expansion device 26, prior to its admission into the evaporator I2. As the liquid is subjected to a'relatively low pressure in the evaporator I2, it is vaporized and absorbs heat from the evapo- 5 rator in a well known manner. This cycle of operation continues during periods of operation of the compressor l8.

Preferably, the expansion device 26 is of the capillary tube type which includes a passage of 40 fixed flow resistance for the refrigerant. The amount of refrigerant passed by the capillary tube 25 is responsive to the difference in pressures obtainingin the condenser I6 and the evaporator I2. Further reference to the flow of refrigerant through tube I6 under varying load conditions will be made hereinafter.

Cooling water for the condenser I6 is obtained from any suitable source under pressure and is conveyed to the condenser by conduit 28. The 5 water is discharged from the condenser by a conduit 29 in which the coil 22 may be connected. The flow of water in the conduit 28 is controlled by a valve mechanism 3| of the pressure reducing type. For the sake of clearness, the valve mechanism is shown of a larger scale than the remainder of the elements of the system.

The valve mechanism 3| includes a casing 32 having inlet and outlet chambers 33 and 34, respectively. A valve 35 controls the flow of water from the inlet to the outlet chamber and is actuated by a pressure responsive element such as, for example, the diaphragm 36'. The latter is subjected on its under side to the pressure of the water in the chamber 34 and is biased in opposition to this pressure by a spring 31. A support 38 is provided for the spring 31, which support is movable for increasing or decreasing the bias of the spring 31 on the diaphragm 36. A second spring 39 is provided for biasing the valve 35 and diaphragm 36 in opposition to the bias of the spring 31.

During periods when the refrigerating ma chine I1 is shut down, the movable support 38 is in its upper position, above thatshown on the drawing. Accordingly, the bias of the spring 31 is reduced and is overcome by the bias of the spring 39 so that the latter holds the valve 35 in engagement with the seat, and therefore, no water flows in the system. During operation of the machine H, the movable support is in the position shown in the drawing so that the bias of the spring 31 overcomes that of the spring 39 and the pressure of the water on the under side of the diaphragm 36, and therefore, the valve 35 is in its open position.

The pressure of the water in the chamber 34 is maintained at a substantially constant value during periods when the valve 35 is open. If the pressure of the water in the chamber 34 rises, the upward force imposed by the water on the diaphragm 36 assisted by the spring 39 overcomes the bias of the spring 31 and moves the valve in closing direction. The flow of water through the valve 35 is throttled so that the pressure in chamber 34 is reduced. Conversely, a

drop in pressure in the chamber 34 below a predetermined value, reduces the upward force on the diaphragm 36 so that the spring 31 effects an opening movement of the valve 35 against the bias of the spring 39 and pressure on the diaphragm. Accordingly, the flow of water through the valve 35 increases and the pressure builds up in the chamber 34.

The pressure maintained in the chamber 34 may be adjusted in any convenient manner as by varying the bias of the spring 31. Accordingly, the movable support 38 may be formed of a collar 4! into which a stem 42 is threaded. The collar 4i may be moved upwardly or downwardly with respect to the stem 42 by rotating the latter so that the bias of the spring 31 and the pressure maintained in the chamber 34 are decreased or increased.

The movable support 38 may be actuated in any suitable manner but I prefer to actuate it simultaneously with the operation of the switch 20. Means are provided for connecting the support 38 to the switch 20 which may include a bell crank 43 connected bya link 44 to a movable member 45 of the switch 20. The member 45 supports the contact 45 which engages a stationary contact 41 in the closed position of the switch 2o. As shown in the drawing, the switch 20 is closed and the bell crank 43 holds the support 38 in its lower or valve-open position. Movement of the member 45 in a counter-clockwise direction opens the contacts 45 and 41 and effects a counter-clockwise movement of the bell crank 43 so that the support 38 moves to its upper or valve closed position.

The switch 20 may include a quick make and break mechanism including a handle 48 pivoted on a pin 49 which may also provide a pivot for the member 45. A spring 51 connects the member 45 and handle 48 which eiTects a snap action of the member 45 as the handle 48 is moved from one position to another.

Operation In the position of the elements of the system shown in the drawing, the refrigerating machine I! is operating as the switch 20 is closed, and water is supplied to the condenser l6 and the coil 22 as the valve 35 is open. The fan 13 operates to translate air cooled by the evaporator l2 to the room Hi. When it is desired to terminate the operation of the system, the switch handle 48 is moved to the left and switch 20 opens the circuit to the motor IS. The valve 35 is simultaneously closed for terminating the flow of cooling Water to the condenser l6 and coil 22. The fan l3 may be stopped or permitted to run for ventilating the enclosure 10 as desired.

The amount of water passing through the condenser l6 and the coil 22 is maintained constant by the valve mechanism 3| and is of such value that, when the load on the compressor l8 or the temperature of the air being cooled and the cooling water temperature are at maximum values, the pressure of the refrigerant in the condenser I6 is as high as is advisable from an eiliciency standpoint. At lower loads, as when the temperature of the air being cooled is below said maximum value, the head or condenser pressure is depressed as the amount of cooling water flowing is always substantially constant and, therefore, the volume of water per unit of weight of refrigerant compressed is greater. Accordingly, the head or condenser pressure rises and falls with increases and decreases in the load or the temperature of the air being treated.

The amount of refrigerant delivered to the evaporator l2 by the capillary tube 26 is responsive to the difference in pressures in the condenser and evaporator. As the head or condenser pressure rises and falls with increases and decreases in load, more refrigerant is delivered to the evaporator 12 at high load than at a lower load. In this connection, the pressure in the evaporator I2 also rises and falls with increases and decreases in the load or the temperature of the air being cooled, but the change in evaporator pressure is at a lower rate than the change in condenser or head pressure. Thereiorc, the difference between the pressures in the condenser and evaporator increases and decreases with increases and decreases in load so that more refrigerant is delivered to the evaporator at high load than at low load.

The system of refrigeration described herein is disclosed and claimed in the aforementioned application of R. E. Holmes. My improvement re sides in a system of this kind in which the means for initiating and terminating the flow of cool ing water and for regulating its rate of flow are incorporated in a single device. A preferred form of my invention also includes means for actuating the device incidental to the adjustment of the switch for controlling the operation oi the refrigerating machine.

In the event or" overheating the refri t gmachine due to any abnormal condition ifa for example, low voltage of the power lines, it is desirable that the motor be deenergized. A normally closed, thermally-actuated switch 52 may be fixed to the casing 2|, which opens fordeenergizing the motor l9 when the temperature of the casing increases to a predetermined value. In this event, it will be apparent that the fiow of cooling water is maintained to cool the condenser IG and the refrigerating machine l'l, so that, when the abnormal condition is removed or when the temperature of the casing 2| is depressed below said predetermined value, the switch 52 closes. against a reduced pressure in the condenser l6 and compressor l8.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible to various changes and modifications without departing from the spirit thereofQand I desire, therefore, that only such limitations shall be, placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. In a refrigerating system, the combination of a water cooled condenser, an evaporator, a

compressor forcirculating refrigerant through the condenser and the evaporator, a source of cooling water for the condenser, a valve movable in response to and controlling the pressure of water delivered to the condenser, and means for moving said valve to closed position for terminating the flow of cooling water to the condenser, independently of the pressure of the water dellvered thereto.

2. In a refrigerating system, the combination of a water cooled condenser, an evaporator, a compressor for circulating refrigerant through the condenser andthe evaporator, a motor for driving said compressor, control means for starting and stopping said motor, a valve movable in response to and controlling the pressure of the water delivered to the condenser to maintain the same substantially constant, and means for moving the valve to closed position for terminating flow of cooling water to the condenser when said control means is adjusted to terminate the operation of the motor.

3. In a refrigerating system, the combination I of a water-cooled condenser, an evaporator, a refrigerating machine including a compressor for circulating refrigerant through the condenser and vaporator, a motoFfor driving the compresstar and including a'casing for housing and hermetically sealing the compressor and motor;

' means for cooling the refrigerating machine, a

switch movable to first and second positions for initiating and terminating operation of the refrigerating machine, a valve for maintaining the flow of cooling water through said condenser and cooling means at a substantially constant rate, mean operable automatically for moving said valve to closed position for terminating the flow of cooling water when said switch is moved to its second position and for permitting said valve to open when the switch is adjusted to its first position, and a normally closed, thermally actuated switch associated with said refrigerating machine for terminating its operation in response to a predetermined abnormal temperature thereof without closing said valve.

4. In a refrigerating system, the combination of a water-cooled condenser, an evaporator, a

The motor I9 is then started compressor for circulating refrigerant through ing cooling water to the condenser, a valve for controlling the flow of said cooling water to the condenser, a spring biasing said valve in opening direction, means for applying the water pressure on the discharge side of the valve for biasing said valve in closing direction, whereby said valve maintains substantially constant pressure of the cooling water supplied to the condenser, and means for substantially removing the bias of said spring to close said valve.

5. In a refrigerating system, the combination of a water cooled condenser, means for supplying cooling water to the condenser, a pressure reducing valve for controlling the flow of cooling water to the condenser and operable to maintain the pressure at which it is supplied to the conpressor, respectively, and means for automatically moving said valve to closed position when said control element is moved to its second position and for permitting said valve to open when the control element is moved to its first position.

6. In a refrigerating system, the combination of a water cooled condenser, means for supplying cooling water to the condenser, a pressure reducing valve for controlling the fiow of cooling water and operable to maintain the pressure at which it is supplied to the condenser substantially constant, an evaporator, a compressor for circulating refrigerant through the condenser and the evaporator, a motor for driving said compressor, a circuitfor supplying electric current -to said motor, a switch in said circuit, and comcondenser substantially constant, an evaporator,

a compressor for circulating refrigerant through the condenser and the evaporator, a control element movable to a first and a second position for initiating and terminating operation of the compressor, respectively, means for automatically moving said valve to closed position when said control element is moved toits second position and for permitting said valve to open when the control element is moved to its first position, and means responsive to excessive temperature of said motor for terminating operation of said compressor without closing said valve.

8. In a refrigerating system, the combination of water-cooled condenser, an evaporator, a compressor for circulating refrigerant through the condenser and the evaporator, means for supplying cooling water under pressure to the condenser, a valve for controlling the flow of said the reactive force of said spring and movable to a first or operative position for increasing the bias of said spring to cause the valve to open and to a second or inoperative position for decreasing the bias of said spring sufiiciently to permit the valve to close, means for biasing the valve in closing direction to cause closing thereof when said spring retaining member is moved to said second position, and means for moving said spring retaining member to said first or to said second position. I

9. A refrigerating system comprising the combination of a water cooled condenser, an evaporator, a motor and compressor unit for circulating refrigerant through the condenser and the evaporator, a circuit for supplying electric current to the motor, control means for initiating and terminating operation of the refrigerating system comprising a switch in said supply circuit, a pressure reducing valve movable in response to and controlling the pressure of the water delivered to the condenser to maintain the same substantially constant, and means for moving said pressure reducing valve to closed position to terminate flow of cooling water to the condenser automatically when the refrigerating system is shut down by opening of said switch.

MILTON KALISCHER.

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