US1586798A

US1586798A - Refrigerating apparatus

Info

Publication number: US1586798A
Application number: US505150A
Authority: US
Inventors: Charles C Hansen; Herbert V Hansen
Original assignee: Refrigerating Specialties Co
Current assignee: Refrigerating Specialties Co
Priority date: 1921-10-03
Filing date: 1921-10-03
Publication date: 1926-06-01
Anticipated expiration: 1943-06-01

Description

June 1 1926. 1,586,798

- I C. c. HANSEN ET AL REFRIGERATI NG APPARATUS Filed Oct. 5; 1921 s Sheets-Sheet 1 Aw inventors:

3mm h1g2, 1,586,798

C. C. HANSEN ET AL,

REFRIGERATING APPARATUS Filed Oct. 5, 1921 3 sheets-sheet 2 3 Sheets-Sheet 5 C c HANSEN ET AL REFRIGERATING APPARATUS Filed Oct. 5, 1921 AQQN June 1 1926.

AQN

Patented I June 1, 1 926.

were STATES cnnntns cfnANs N AND-HERBERT- v. Hansen,

slonons TO BEFBIGERATING srncmmms COMPANY,- or cnronoo,

Loonronarron or rumors.

I -1,ss6,79s PATENT OFFICE.

OF FOREST PARK, ILLINOIS, AS-

ILLINOIS, A

I nnrmennermo nrrmrus.

Application filed October 3,1921. Serial No. 505,150.

The invention relates to automatic controlling mechanism for refrigeratingsys tems.

The heavy starting load upon the motor for driving the compressor, due to'the comparatively heavy fly-wheel and the greater density of the'gas in the. compressor cylinders during the starting period, is so great and of such duration as to render fuse pro.- tection suitable. for normal running load insufficient for the starting load and the same is true with respect to overload relays when the latter are used in automatically controlled refrigerating systems.- One object of the invention is to improve the automatic controlling mechanism for the motor responsively to any.

overheating of the motor, instead of by auxiliary devices, such as fuses and overload relays. By providing a thermostat responsive to the temperature of the motor and mechanism for causing the motor to stop whenever overheating occurs, efiicient provision is made for discontinuing the operation of the compressor and motor whenever there is any irregularity in the system which puts an excessive overload upon the motor.

I 'In'the use of regulating expansion valves' for controlling the flow ofrefrigerant to the refrigerating line or room, it has been found that the high yelocity of the refrigerant soon cuts the valve seat so that it will permit leakage of the refrigerant during idle peri- .ods of the system. As the evaporators are at a much lower temperature than the condenser and receiver, the refrigerant will pass into the evaporators through the defective valve to the full cubical capacity of the evaporator, and the pressure being then equalized on both sides of the valve, the refrigerant will condense and when the thermostat makes contact for operation'the' compressorusually draws solid slugs of liquid refrigerant which is exceedingly dangerous to a compressor, the latter being usually constructed for compressing gas and not liquid and cracked cylinder heads sometimes result from this cause. Another object of the invention is to overcome this defect. This ob- 'ject is attained by providing an additional tight-closing valve at a point in the system where the liquid refrigerant moves slowly and the temperature is even, with means for automatically .closing this valve until the refrigerating system or evaporators can absorb it in the form of gas and thus prevent damage to the compressor through flooded evaporators.

In practice, it sometimes occurs that the pressure-regulating expansion valve becomes clogged which results in pumping a vacuum on the low or evaporator side ofthe system, so that the compressor will draw air into the system around the compressor shaft and through the valve stufiing boxes, .thus contaminating the entire charge of refrigerant and causing dangerously high pressure through OVeICI'OWdHlg the cubical capacity with gases which are not condensible by the compressor usually adapted for refrigerant. Another object of the invention is to ,overcome this defect and-this object. is attained by providing mechanism for controlling the mechanism which'will stop'the com ressor whenever the suction pressure falls be ow at mospheric pressure. r

Another object of the invention is to provide improved means for controlling the operation of the system responsively to the pressure of the condensing liquid so that the compressor will be stopped when the water supply is insufficient for proper condensing. This object'is attained by providing a \switch controlled by a device which is operated by the condensing water and controls the supply of liquid refrigerant to the expansion valve.

Other objects of the invention will appear from the description.

The invention consists in the several novel features hereinafter set forth and more par ticularly defined by claims at the conclusion hereof.

In'the drawings: Fig. 1 is a diagram of a refrigerating system embodying the invention. Fig. 2 is a section of the valve for controlling the supply of water to the condenser and its operating mechanism and Fig. 3 is a front view thereof. Fig. 4 is a section of one of the pressureoperated switches. Fig. 5 is a section of the device which is controlled by the pressure of condensing water. i

The invention is exemplified in a refrigerating system comprising a motor B which is suitably connected to drive a refrigerant compressor 0; a condenser P suitably connected to receive refrigerant from the high pressure side ofthe compressor 0 and to dischar e the refrigerant into a liquid receiver d; an automatic pressure regulating expansion valve S connected to receive refrigerant from the receiver Q; and an evaporator or refrigerating line R which is connected to receive refri erant from the low side of the valve S and to the suction side of the compressor 0, as well understood in the art. A thermostat L of suitable construction is provided in the refrigerant room or compartment and is connected as hereinafter more fully appears to control the operation of the system responsively to temperature changes in said room or compartment.

The apparatus comprises a thermostat N which is connected to the casing of motor B so as to be responsive to. the temperature changes in the motor. This thermostat is connected by means of connections hereinafter described, to cause the controlling circuit for the motor B to be opened so that the motor will be stopped whenever the motor becomes overheated through any cause whatsoever. This thermostat is electrically connected to an electro-magnet I which comprises a helix 17 and a magnetically operated switch 31 which is included in the circuit for controlling the operation of the motor B, as hereinafter more fully appears.

A supply pipe m for condensing water is connected to a normally closed valve M which controls the flow of water to the condenser P through a pipe m. Valve M comprises a casing 80 provided with a seat 81 with a port 82 between the inlet and outlet sides of the casing, a valve 83 adapted to close the seat and port and provided with a stem 84:, and a spring 85 for holding the valve normally closed. The magnet A for controlling the valve M comprises a helix 27, a core 66 and an armature 67 which is mounted on a weighted lever 40. Said lever is pivoted, at 69, to a bracket 70 which is mounted on a backboard 71 and its lower end is connected by a link 72 to operate a toggle linkage which consists of a link 7 3 pivoted at one end to bracket 70, as at 74, and at its other end to a link 75, the lower end of which is pivoted at 76 to a slide 77 which is mounted in a bracket 78 which is secured to backboard 71 and to which the valve casing 80 is secured. The lower end of the slide 77 is provided with a hammer 79 which is normally spaced from the upper end of stem 84 and is adapted to impart a blow to said stem to open the valve against the force of spring 85 and the pressure of fluid on the inlet side thereof. The linkage is arranged so that it will pass into substantially dead-center relation when it is operated to open the valve so that the minimum magnetic force will be required to keep the valve open. Lever 40 is weighted at one side so that it will hold the linkage normally in off-center position and will retract it when the helix 27 is deenergized. This weighting of the lever also causes it to acquire momentum during the initial operation of its magnetically operated stroke so that the hammer 79 will, through the linkage, impart a forcible hammer blow on the valve stem 84 of sufficient force to open the valve. This mechanism exemplifies a water valve for controlling the flow of condensing water to the condenser which is magnetically operated to open the valve and by which the valve will be held open while the helix of the magnet remains energized.

The pivot pin 69 is secured to lever 40 and 80 to an arm 43 which carries a switch 42 which is adapted to close a circuit for the operation of the compressor motor B when and while the magnet A is energized. The magnet A which controls the valve M and the switch 42 is electrically connected, as hereinafter appears, and exemplifies a magnet for controlling a switch which controls the starting and stopping of the motor and the opening and closing of the condensing water valve M.

A pressure-controlled device D is includ ed in the condensing water pipe m and comprises a casing to the upper portion of which a pipe 121/ from the valve M is connected and to the lower end of which the corresponding pipe leading to the condenser is connected; a plunger 91, slidably mounted in the casing and normally raised by a spring 92; and astem 93 on the plunger. The plunger is adapted to be operated against the force of spring 92 by the pressure of the water on the upper side thereof and is provided with ports 9-l which will pass into communication with the outlet pipe when the water is of sufficient pressure to properly cool the refrigerant in the condenser.

A switch 62 is secured to the upper end of the stem 93 and controls and is included in a circuit which is adapted to control the operation of an electro-magnet K which controls the flow of liquid ammonia to the expansion valve S from the receiver Q.

The magnet K is adapted to operate a hammer lever 56. The valve E and its connections with lever 56 are of the same construction as the magnet A and valve M so that a detail description is not deemed necessary. The magnet K is adapted to operate the lever 56 to impart a hammer blow to the stem of the valve E and to release the valve so it will be closed by its spring when the helix 55 of magnet K is deenergized. The valve E exemplifies a freeflow control as distinguished from the needle valve control of a pressure reducing or expansion valve. The port controlled by the valve is of large area so that the velocity of the refrigerant does not cut away the valve seat as is the case in expansion valves with restricted ports. The helix 55 of magnet K is included in the circuit controlled by the switch 62 and is electrically connected as hereinafter more fully appears.

A fluid pressure operated device F is connected by a pipe 52 to reccivelrefrigerant from the high side of the refrigerant line and operates a switch 37 which is included in the circuitfor controlling the operation of the compressor motor. This device is adapted to shift said switch to open said circuit and cause the stoppage of the compressor motor when there is excessive condenser pressure in the high side of the refrigerant line. A fluid pressure operated device G is connected by a pipe 53 to the suction or low pressure side of the refrigerant line and operates a switch 35 which is also included in the circuit for controlling the operation of the compresser motor and is adapted to interrupt said circuit to cause the compressor motor to stop when the pressure in the low or suction side of the line becomes abnormally low. V I

A fluid pressure operated device H is also connected

byv pipes

64 and 53 to the low pressure side of'the refrigerant line and opcrates switch 59 which is included in a circuit for controlling. the operation of the li uid refrigerant valve E. This device is a apted to open the switch when the pressure in'the suction side of the refrigerant line becomes excessive or abnormal to cause the magnet'K; to be deenergized so that the valve E will be closed to cut off the supply of liquid refrigerant to the expansion valve S. The pressure devices F, G and H are similar in operationlgand construction, except for variation or adjustment necessary to cause them to act responsively to the respective pressures in the refrigerating line at points to which they are respectively connected. Each of said devices comprises a casing 102 provided with an inlet 103 to which the fluid pressure is connected; a diaphragm 104 exposed to pressure inthe fluid pipe; a plunger head 105 disposed to be operated in one direction by the diaphragm; a spring 106 for applying pressure and resistance to'the plunger head corresponding to the pressure at which the device is to be operated; a stem 107 on the plunger; a lever 108 is pivoted at 110 to' a bracket 109 which is fixed to casing 102; a lever 111 pivoted, at

112, and operative by lever 108 through a' pin and slot 113; and a switch-lever 0 erated by lever 111. A spring 114 is app ied to retract and to restore the switch to nor- Y mal condition when pressure in the casing becomes normal. Each switch 1s suitably mounted in a box 115mg the casing 102.

The' thermostat L in the refrigerating' room is connected to the helix 22- of a magnet J which, when energized, operates a switch 26 to close the circuit for controlling the operation of the compressor motor when the temperature in the refrigerating room ex ceeds a predetermined point. Said magnet also operates a switch 25 which is included in the circuit for controlling the operation of the magnet K which controls the-valve E.

The operation of the apparatus will be as follows: Assuming the compressor to be idle and an increase of temperature occurs in the refrigerating room, the thermostat L will be operated to close a circuit at contact 20 as follows: line conductor 14, one member of switch 15, conductor 16, contact 20, thermostat L, conductor 21, helix 22 of magnet J, conductor 23, the other member of switch 15 and line conductor 24. Thereupon, the helix 22 of magnet J will be energized to operate. an armature 26 to close the circuit through the helix 27 of magnet A to operate said magnet for the purpose of operating the water valve M and closing a circuit for the opoperation of the compressor motor 13 as follows: line conductor 14, one member. of

switch 15, conductors 28, 29, helix 27, conductor 30, armature 31, conductor 32, armature 26, contact 33, conductor 34, switch 35,

conductor 36, switch 37, conductors 38, and i 23, the other member of switch 15 and lineconductor 24. The closing of said circuit will energize the helix 27 to operate the armature on hammer lever 40 and to open the water valve M so thatcondensing liquid will be supplied to the condenser P'of the refrigerating system. The operation of the hammer lever 40 will simultaneously close a circuit for the operation of the compressor motor B as follows: line conductor 14, one member of switch 15, conductors 28, 41., switch 42 carried by the arm 43 on the hammer armature. 40, conductor 44, windings of motor B,

conductors

45, 23, the other member of line-switch 15 and line conductor 24. hen this circuit for motor B is closed, and all of the conditions inthe system are normal, the motor B will be operated to drive the compressor 0 until the temperature in the refrigerating room drops to the predeternormal electrical conditions or an overload,l

the thermostat N on motor B will close a circult to interrupt the circuit for the helix 27 of magnet A as follows: line conductor 14, one member of line-switch 15,

conductors

16, 46, helix 47, conductor 48, thermostat N, contact 49,

conductors

50, 23, the other member of line-switch 15 and line conductor 24. Said circuit will energize the helix 47 of the magnet I and operate armature 31 to open the circuit for energizing the helix 27 and maintaining the motor circuit. Thereupon, the motor circuit will be interrupted at arn'lature 81 and the helix 27 will be deenergized and the hammer'armature 40 will automatically open the motor circuit at switch 42 and also close the water valve M. This mechanism exemplifies thermostatically controlled means for controlling the operation of the compressor motor so that it will be discontinued in event the motor should become excessively heated from abnormal conditions.

If, during the operation of the compressor, the condensing pressure on the high side of the refrigerating system 52 should become excessive, the pressure controlled device F, responsive to excessive pressure,

will operate the switch 37 to open the circuit for helix 27 and thereupon the switch 42 will be automatically opened to discontinue the operation of the compressor motor B and to close valve M. As soon as the pressure in the high side of the refrigerating system is restored to normal, the pressure operated device F will close the switch 37 and re-establish the circuit for thehelix 27 which controls the compressor motor circuit and the water valve M. This construction exemplifies mechanism for automatically stopping the compressor motor when the pressure in the high side of the refrigerat ing system becomes excessive and for automatically continuing the operation of said motor when said pressure becomes normal.

If the pressure in the low or suction side of the line becomes abnormally low, so that the compressor will suck air which is substantially non-condensible in a refrigerant cycle and which would result in a permanent high pressure on the high side of the line, the pressure operated device G, which is connected by a pipe 53 to the low side of the refrigerant line, will operate the switch 35 to interrupt the circuit for the helix 27 and thereupon the compressor motor circuit will be opened at switch 42 to stop the motor and the water valve M willbe simultaneously closed. lVhen the water supply is cut off, switch 62 will open and open the circuit for helix and cause. hammer lever 56 to close valve E and shut off the flow of refrigerant to the line. This construction exemplifies means for discontinuing the operation of the compressor -motor; cutting of the flow of refrigerant to the expansion valve; and closing the water valve when the pressure in the low or suction side of the line becomes abnormally low.

lVhen the circuit for the helix of the thermostatically controlled magnet J is energized, it will simultaneously operate armature 25 to establish a circuit for operating the helix 55 of magnet K as soon as the circuit for the operation of the compressor motor 13 has been close-d at switch 42. \Vhen the helix 55 is energized, it will operate the hammer lever 56 to open valve E so that refrigerant can freely flowfrom the receiver to the expansion valve S. The circuit for operating magnet K for this purpose will be as follows: line conductor 14, one member of switch 15,

conductors

28, 41, switch. 42,

conductors

44, 57, armature 25, conductor 58, switch 59, conductor 60, helix 55, conductor 61, switch 62,

conductors

63, 45, 23 and line-conductor 24.

If, during either a shut-down or operating period, the pressure in the low side of the line should become excessive through failure of the expansion valve to properly regulate or from any other cause, the pressure controlled device H, which is connected to the low side of the line by

pipes

64 and 53, will operate switch 59 to interrupt the circuit for the helix 55, so that under such conditions the valve E for controllingthe supply of liquid refrigerant to the expansion valve will remain closed until normal pressure isre-established in the suction side of the refrigerant line when the compressor is operated responsivel y to the thermostatic control and there is excessively high pressure in the low side of the line, the valve IE will remain closed, causing the comprcssor to suck the fluid from the low side of the line and force it into the high side until the pressure is reduced to normal, whereupon switch 59 will he closed and the valve E will be opened to admit refrigerant to the expansion valve.

This construction exemplifies mechanism for automatically cutting off the passage of liquid ammonia to the expansion valve when the pressure in the low side of the line is excessively high.

If the pressure of the condensing water is insuflicicnt for proper cooling, the device D, which is interposed between the water line and the valve M and the condenser, will keep the switch 62 open so that the helix 55 will not be energized and the ammonia valve E will remain closed' As a result of operating the compressor with insufficient water supply, the pressure in the high side of the line will become excessive and the circuit for the helix 27 will'be opened at switch 37 by pressure controlled device F or the pressure in the low side of the line will become excessively low, so that the pressure-controlled device G will open said circuit at switch 35. Under either condition, the helix 27 will be deenergized and the operation of the motor B will be discontinued by the breaking of its circuit at switch 42. lVhenever the stopping of the motor occurs while the thermostat L is engaging contact 20, as the result of ahigh temperature in the refrigerating room, the motor will be restarted as soon as normal conditions are established in the high pressure or low pressure side of the line. If the operation of the motor B is discontinued as the result of deficient Watersupply, and the normal conditions in the refrigerant line are established, the motor will be restarted and the water valve M be reopened, and when the water supply becomes sufficient, the switch 62 will be closed so that the refrigerating operation will be continued.

e The invention exemplifies an automatic refrigerating system in which provision is made for thermostatically controlling the operation of the compressor motor, so that when, on account of overload or any other abnormal condition, the motor becomes overheated it will be automatically stopped; in

which an automatically controlled valve is used to control the flow of liquid ammonia to the expansion valve for the purpose of preventing leakage when the expansion valve becomes defective; in which provision is made for automatically stopping the compressor motor when the pressure in the low side of the line becomes abnormally high and when it becomes abnormally low and also when it becomes abnormally high in the high pressure side of the line; in which provislon is made for automatically opening the condensing water-valve by an electromagnet; in which provision is made for outtingofi the supply of liquid ammonia to the-- expansion valve when the water pressure is insu'flicient and in which substantially the same degreeof eificiencyis attained as is usually done in manually controlled systems.

The invention is not to be understood as restricted to thedetails set forth, since these may be modified within the scope of the appended claims, without departing from the spirit and scope of the invention.

Having thus described the invention, what we claim as new and desire to secure by Let-. ters Patent, 1s:

1. In refrigerating apparatus, the combination of a compressor, a refrigerant line,

a liquid receiver, a condenser, an automatic expansion valve for controlling the supply of refrigerant to the line, free-flow valve between the expansion va ve and. the .receiver, mechanism. for automatically controlling the operation of the motor, and means operated by pressure of the refrigerant in the line for"automatically opening and closing said free flow valve. I

2. In refr'gerating apparatus, the com bination of a compressor, a refrigerant line,

a liquid receiver, a condenser, an automatic expansion valve for controlling the between the expansion valve and the receiver, mechanism for automatically controlling the operation of the motor, and mechanism for automatically opening said free flow valve when the motor isoperated, and ,closingit when the motor isstopped comprising a device operated by pressure of the refrigerant in the'line'.

4;. In refrigerating apparatus, the com bination of a compressor, a refrigerant line connected to the compressor, a motor for driving the compressor, and mechanism for automatically controlling the operation of the motor comprising a device connected to' be operated by pressure in the low side of the refrigerant line,- and means controlled by said device for cutting. off the supply of refrigerant to the line when the pressure in the low side of the line becomes excessive.

5. In refrigerating apparatus, the combination of a compressor, a refrigerant line connected to the compressor, a motor for driving the compressor, and mechanism for automatically controlling the operation of the motor comprising a device connected to be operated by pressure in the low side of the refrigerant line, and automatic means controlled by said device for cutting off the supply of refrigerant to the line when the pressure in the low side of the line becomes excessive and for permitting refrigerant to besupplied to the line when normal pressure is restored. T

-6. In refrigerating apparatus, the combination of a compressor, a refrigerant line connected to the compressor, a motor for driving the compressor, and mechanism. for

automatically controlling the operation of the motor, comprising. a device connected to be operated by pressure in the low side of the refrigerant line, avvalve for controlling the supply ofrefrigerant to the line, and

automatic means controlled by said device to automatically close the valve when the pressure in the low side of the line becomes excessive and to open the valve when normal pressure is restored. j

CHARLES C. HANSEN. I

HERBERT v. HANSEN.