US2566192A - Flow control means in refrigerating apparatus - Google Patents

Description

Aug. 28, 1951 GRQQMS 2,566,192

FLOW CONTROL MEANS IN REFRIGERATING APPARATUS Filed Dec. 11, 1946 Patented Aug. 28, 1951 FLOW CONTROL MEANS IN REFRIGERATING APPARATUS Albert 0. Grooms, Dayton. Ohio, asslgnor to General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application December 11, 1946, Serial No. 715,569

9 Claims. 1

This invention relates to refrigerating apparatus and more particularly to means for controlling the flow of refrigerant from the condenser to the evaporator.

and restrictors. ideal from every standpoint.

. ing period of the system.

ing period of the refrigerating system,

only without permitting the flow of liquid.

operating.

the compressor.

of a magnetic material.

operating period.

of the present invention is clearly shown.

In the drawing:

frigeratlng system.

a compressor 20 for withdrawing evaporated refrigerant from the evaporator 22 and for forwarding the compressed refrigerant o a condenser 24 where the compressed refrigerant is The upper guide 36 The valve 44 The upper valve seat 40 is movable The lower half 52 is mounted upon Since the walls In addition to hand valves there are four comliquefied. Connected between the condenser 24 mon types of refrigerant flow control devices, and the evaporator 22 is a high side float valve namely high and low side floats, expansion valves embodying my invention. This high side float No one of these appears to be valve has a casing of non-magnetic material such A considerable loss as copper, brass or bronze including a lower shell in efliciency of a refrigerating system is entailed body 28, and an upper shell body 30, together by improper liquid flow. Some of this loss is with a brass inlet connector 32 and a brass outcaused when liquid flows from the condenser to let connector 34. These p rts are P ly the evaporator during the idle period of the sysbonded togeth r y Silver e ing or other suittem. A loss in efliciency may also be caused ble m ans.

when the evaporator receives too much or too he upper and lower connectors 32 and 34 are little refrigerant at any time during the operateach Provided h guides 35 nd 3 h incl ing four guiding prongs.

It is an object of my invention to provide a guides the valve seat 40 mounted D a IOW satisfactory control and flow of liquid refrigerant valve Stem 42 While the lower ve de 38 to the evaporator at all times during the operatguides the Valve 44 ed Upo the l we end of this same hollow valve stem 42.

It is another object of my invention to provide is adapted to seat upon a seat p ided at t an equalization of pressure between the high and mouth of the outlet passa e 4 in the outlet conlow sides of the system during the idle period nector 34.

and is adapted to be closed when it moves up- It is another object of my invention to provide Wardly int n m nt w th t ion ry an arrangement whereby the flow of refriger nt valve needle 48 provided on the inlet connector to the evaporator begins when the system starts The inlet connector 33 has branch inlet D sa es 50 permitting the liquid to flow from the Th objects are tt i d by providing a condenser 24 into the interior of the float valve frigerating system employing a high side float 25 at all timescontrol having a hollow valve stem. The interior The float is made in We l s of thin hot of this stem is closed when the liquid level in the rolled Steelfloat chamber is high and it is opened when the a Shoulder at the upper end or the valve 44 and liquid level in the float chamber is low to permit the upper half 54 telescopes ov r the lower half the equalization of gas during the idle period of 52 and is supported by a Sleeve 56 po the hol- The float chamber enclosure is low valve stem 42 and extending to the valve of non-magnetic material but the float itself is seat member This assembly ay be brazed An electromagnetic e d Welded to ercoil connected in series with the phase winding the flea-t a y t to secure light weigh is provided for magnetically lifting the float durthe interior of the t i pr ly filled with a ing the starting period of the motor to prevent gas such as hydrogen. u der sufficient pressure initial starvation of the evaporator during the, to p v t collapse of the float under the hi h st pressure expected to be encountered at any time.

Further objects and advantages of the pres- A Small amount of a Volatile liquid por may ent invention will be apparent from the followbe used instead of the gas f t h s the p p ing description, reference being had to the a pressure temperature characteristics to provide companying drawing, wherein a preferred form sufllcient internal pressure to balance the highest refrigerant pressure encountered. The float is provided with the sealing tube 58 through which The figure shows a sectional view of a high the float is'charged with gas or vapor and then side float embodying my invention, together with sealed. the remaining portions of the compression re- Wrapped around the upper shell body 30 is an electromagnet coil 80 which is connected in series -.Referring now to the drawing, there is shown with the phase winding 62 01' the electric motor 84. The other end of the electromagnet coil 89 is connected thro gh the conductor 44 and the contacts 68 of the starting relay I to the supply conductor 12. The supply conductor 12 through the operating coil of the relay is connected to the main winding 14 of the motor 64. The common Junction of the main and phase windings I4 and 62 is connected to the thermostatic switch means 16 which controls the connection with the other supply conductor 18.

In operation, when the evaporator 22 reaches a predetermined high temperature, the snap-acting switch 16 will close causing current to flow from the supply conductor 18 through the main winding 14 and the coil of the starting relay III to the other supply conductor 12. The energization of the relay I0 will close the contacts 68 thus energizing the phase winding 62 and the electromagnet coil 60. This substantially simultaneously causes the starting of the motor 64 and the operation of the compressor 20 as well as'causes the electromagnet coil 60 to magnetically attract the float 52, 54 of the high side float to lift the valve 44 to open position and to raise the valve seat member 40 into contact with the valve 48 to prevent the flow of gas through the hollow valve stem 42.

As soon as the motor reaches a suflicient speed, the starting relay 10 will open to deenergize the phase winding circuit including the electromagnet coil 60. The electromagnet 60, will not be energized until the next starting period of the motor 64. Thus at all other times the float valve will operate in accordance with the liquid level within the float chamber. However, the magnetic lifting. of .the float 52-, 54 will permit a .supply of liquid toflow into the evaporator 22 at the beginning of operating cycle to insure that sufllcient liquid is present in the evaporator to assure immediate evaporation and cooling In a :short time, the compressor and condenser will supply sufficient liquid to the float chamber to lift the float in the usual manner to assure a normal supply of refrigerant to the evaporator 22.

To assure equalizations of the pressures during the idle period of the system, the valve stem 42 has been made with a very small. hollow bore.

When the operation of the compressor ceases liquid will continue to flow from the float chamber until the level is reduced sufliciently to permit closing of the valve 44. This will prevent continuation of the liquid flow. Restricted gas flow, however, is permitted by the lowering of the upper valve seat 49 to permit high pressure gas from the condenser 24 and the float chamber to flow slowly through the hollow valve stem 42 directl into the outlet passage 48. As is plainly evident from the drawing, the hollow valve stem 42 continues directly through the valve 44 to the outlet passage 46 so that gas flow is permitted even though valve 44 is in the closed position. This permits equalization of pressures between the condenser 24 and the evaporator 42 by the flow of gas. This equalization of pressures permits the use of a motor with low starting torque without any other form of unloading device.

The hollow valve stem functions without interfering with the operation of the valve 44, and

' the closing of the upper end of the hollow valve stem during the operating period prevents any lo s in efficiency clue to the passage of uncondensed vapor into the float chamber. As the "pressure differences are small,'-the problem of preventing gag the system can be manufactured at a relatively low cost, since a low starting torque motor can be used. The high side float construction controls the liquid supply during the operating period to the best advantage.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows:

l. Refrigerating apparatus including compressing, condensing and evaporating means, a float controlled valve means for controlling the flow of liquid refrigerant from the condensing to the evaporating means, and means for conducting refrigerant gas from the condensing to the evaporating means when said valve means is closed and for preventing the flow of gas when said valve means is open.

2. Refrigerating apparatus including compressing, condensing and evaporating means, a float controlled valve means for controlling the flow of liquid refrigerant from the condensing to the evaporating means, said float controlled valve including a casing having an inlet and an outlet, a float within the casing having a valve for closing the outlet, means providing a gas passage by-passing said valve, and a second valve controlled by said float for closing said gas passage.

3. Refrigerating apparatus including compressing, condensing and evaporating means, a high side float control for controlling the flow of liquid refrigerant from the condensing means to the evaporating means, said float control including an electromagnet coil wound about said casing and a float in the form of a hollow member having wall portions of magnetic material located in the magnetic field of said electromagnet coil and constituting an armature for said electromagnet coil, said casing having wall portions of non-magnetic material adjacent said electromagnet coll, an electric motor for driving said compressing means. and control means for said motor and said electromagnet coil.

4. Refrigerating apparatus including compressing, condensing and evaporating means, a float controlled valve means for controlling the flow of refrigerant-from the condensing to the evaporating means, said float controlled valve means including a casing having an inlet and an outlet, 9. float member within the casing provided with a means for closing said outlet, said float member having a gas passage extending through it to said outlet, said casing being provided with closing means cooperating with said float member for closing said gas passage when said float member is in the position wherein the outletis open.

5. Refrigerating apparatus including compressing, condensing and evaporating means, a float controlled valve means for controlling the flow 01 refrigerant from the condensing to the evaporating means. said float controlled valve means including a casing having an inlet at the top and an outlet at the bottom. a float member within the casing provided with a valve means at its lower end for closing said outlet, said float member being provided a gas passage extending from its upper portion to said valve means to discharge into said outlet, said casing being provided with closing means cooperating with said float member for closing said gas passage when said valve means is in the open position.

6. Refrigerating apparatus including compressing, condensing and evaporating means, a high side float control for controlling the flow of liquid refrigerant from the condensing to the evaporating meansyelectrically operated means for opening said float control, an electric motor for driving the compressing means, said motor having a starting circuit arrangement for accelerating the motor from an idle condition to the switchin speed range which is less than the normal running speed of the motor, said motor also having a running circuit arrangement for accelerating the motor above the switching speed range for operation at the normal running speed, said electrically operated means being electrically connected to said starting circuit arrangement so that it is energized whenever the starting circuit arrangement is energized and is deenergized whenever the starting circuit arrangement is discontinued, and a starting control for energizing said starting control arrangement and said electrically operated meanswhenever the motor is operating below the switching speed range, said starting control being provided with automatic circuit changing means responsive to the operating condition of the motor in the switching speed range for simultaneously deenergizing said electrically operated means and changing the starting circuit arrangement to the running circuit arrangement when the motor passes through the switching speed range during acceleration.

7. Refrigerating apparatus including compressing, condensing and evaporating means, a high side float control for controlling the flow of liquid refrigerant from the condensing to the evaporating means, electrically operated means for opening said float control, an electric motor for driving the compressing means, said motor having a starting circuit arrangement for accelerating the motor from an idle condition to the switching speed range which is less than the normal running speed of the motor, said motor also havin a running circuit arrangement for accelerating the motor above the switching speed range for operation at the normal running speed, and a starting control for simultaneously energizing said electrically operated means and said starting circuit arrangement upon each start of the motor, said starting control being provided with automatic circuit changing means responsive to the operating condition of the motor in the switching speed range for simultaneously deenergizing said electrically operated means and changing the starting circuit arrangement to the running circuit arrangement.

8. Refrigerating apparatus including compressing, condensing and evaporating means, a float controlled valve means for controlling the flow of refrigerant from the condensing to the evaporating means, said float controlled valve means including a casing having an inlet at the top and an outlet at the bottom, a float member with-in the casing provided with a valve means at its lower end for closing said outlet, said float member being provided a gas passage extending from its upper portion to said valve means to discharge into said outlet, said float member being provided with an upwardly extending tubular extension forming the upper end of said gas passage, the upper end of said extension being provided with a valve seat surface, said casing being provided with guide means and an upper valve memher for guiding said extension into contacting and closing engagement with the upper valve member to close the upper end of said gas passage when said float member rises to lift its valve means at its lower end to the open position.

9. Refrigerating apparatus including a low side comprising evaporating means and a high side comprising compressing and condensing means and a high side float control for controlling the flow of liquid refrigerant from the high side to the low side, electrically operated means for-admitting liquid refrigerant to the low side from the high side, an electric motor for driving the compressing means, said motor having a starting circuit arrangement for accelerating the motor from an idle condition to the switching speed range which is less than the normal running speed of the otor, said motor also having a running circuit arrangement for accelerating the motor above the switching speed range for operation at the normal running speed, and a starting control for simultaneously energizing said electrically operated means and said starting circuit arrangement upon each start of the motor, said starting control being provided with automatic circuit changing means responsive to the operating condition of the motor in the switchin speed range for simultaneously deenergizing said electrically operated means and changing the starting circuit arrangement to the running circuit arrangement.

Number Name 1,829,517 Hilger Oct. 27, 1931 2,133,948 Buchanan Oct. 25. 1938 2,133,960 McCloy Oct. 25, 1938

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