US1490367A - Refrigerating system - Google Patents

Description

A in 15 1924.. 1,4903? A. R. EARNSHAW REFRIGERATING SYSTEM Filed Jan. 27. 1922 INVENTOR. iH/mrfl flamsham A TTORNEYS.

Patented Apr. 15, 32%,

racer TENT REFRIGERATING- SYSTW.

Application filed January 27, 1922. Serial No. 532,12 t.

To all whom it may concern.

Be it known that I, ARTHUR R. EARN- SHAW, a citizen of the United States, residing in Wynnewood, in the county of Montgomery and State of Pennsylvania, have invented certain new and useful Improvements in Refrigerating Systems, "whereof the following is a specification, reference being had to the accompanying drawing.

This invention relates to refrigerating machines, and more particularly to those intended for domestic use, and has for its principal object to simplify the construction of such machines to the extent of eliminating all valves or devices which require constant attention or manipulation, thus rendering the operation of the machine automatic and free from errors of adjustment. This is accomplished primarily through the particular design and arrangement of the Well known elements of a so-called flooded type of refrigerating machine, by adapting the same to domestic use, whereby the highest point of efliciency in operation is attained, and secondarily through the use of certain details of construction and new elements of a simple nature, cooperating mutually to accomplish, in my new design of machine all the functions necessary in the operation of an automatic refrigerating machine, which functions were heretofore performed only by means of regulating devices of a more or less complex structure.

These and other objects are accomplished by virtue of my new improvements in refrigerating systems, the preferred embodiment of which I have shown in the accompanying drawing which illustrates in a diagrammatic manner the various elements of the invention and the relative arrangement of the correlated parts.

With reference to the drawing, 10 indicates a pump or compressor of the character and design usually employed in domestic refrigerating machines, and 11 indicates a motor coupled thereto. The condenser, shown at 12-, is of the usual type, and is fed by the compressor through the connection 13. The present invention is not concerned particularly with the character or design of the compressor, motor or condenser, except to the extent that the condenser should be designed so as to be free from trap cui-desacs. or recesses of any kind in which active .refrigerant might collect instead of passing to the cooling coil. All of the essential or fundamental elements of a refrigerating system may be employed, if desired, as my improvements relate more particularly to the cooling element, or unit, in which the refrigerant vaporizes by surface evaporation or boils off to secure a low temperature and to means for securing temperature control in a slmple manner. The discharging end of the condenser is connected by means of a riser 14:, a horizontal line 15, and drop line 16 to a reservoir 17 at a point adjacent the upper portion of the latter. A valve casing 18 is interposed in the drop line 16 at a point closely adjacent to the reservoir, and the valve casing is designed to house a valve mechanism of any desired construction (one example being a conventional form of float valve) which is so designed as to open when liquid refrigerant is present in the valve casing to the end that the liquid refrigerant may pass through the casing; past the valve and into the reservoir 17, but which will close automatically, by gravity or otherwise, when no liquid is passing through the drop line 16 or is present in the valve casing; thus preventing the return of gas or refrigerant vapor to the condenser. A cooling coil is indicated at 19, having its lower end in communication with the reservoir, and having said end extending downward into the reservoir as shown at 20, constituting the reservoir outlet, the latter being spaced for a short distance from the bottom of the reservoir. A restricted aperture or vent is formed in the wall of the outlet pipe 20 at a point in close proximity to the top wall of the reservoir, but within the latter, as indicated at 21. The upper or discharge end of the cooling coil is in communication with the lower portion of a tank, closed receptacle or the like, 22 constituting a trap. A return pipe 23 is connected at one end to the upper portion of the trap 22, while its other end is connected to the intake of the compressor 10. A branch 2& is provided in the return 23, and is led to a pressure controlled device 25 of any suitable design which is adapted to operate an electric switch 26, the latter controlling the flow of current to the motor ll. These parts are so designed that when the pressure in the s stem is at a minimum. the switch 26 will be open and consequently the motor will not run, and vice versa. Suite-hie means should be provided as part of the pressure controlled switch to afford adjustment so that the points of minimum and maximum pressure at which the switch 26 is to operate, maybe varied according to conditions, and

subsequently fixed when the conditions be-- come unchangeable. Particular attention is directed to the design of the cooling coil, reservoir and trap 22. These elements should bear a capacity ratio to the capacity and design of the remainder of the system, so that the reservoir 17, coil 19 and trap 22 may contain all of the active refrigerant in the system and still leave some unoccupied space in the u per portion of the trap. If the reservoir 1 be enlarged to furnish sufficient cooling surface and then partially filled with refrigerant leaving a space to the top, approximately the same effect and action will be produced, without the use of either coil or trap.. By active refrigerant, I refer to the refrigerant employed, such as ammonia, when said refrigerant is in a li uid state, the refrigerant being passive W en in a gaseous state. Attention is also directed to the fact that the lower end of the drop line 16 is preferably carried between the convolutions of the coling coil 19, so as to be in close proximity thereto. The valve casin 18 is also located as close to the cooling coi as practicable.

From the foregoing description of the parts of the system, it will be seen that in operation the gaseous refrigerant is compressed in the condenser and pipe connecttions between the compressor and the valve casing 18 until the gas liquefies, whereupon it is permitted to fiow into the reservoir, and thence into the cooling coil 19 and trap 22 partially filling the latter. Evaporation of the liquid refrigerant takes place, absorbing heat radiated from parts or the air surrounding the cooling unit, and the gaseous refrigerant is then conducted by the return 23 to the compressor and the cycle is repeated. Practically, the operation is more or less continuous as the eva oration of the refrigerant is constant. owever, it will be noted that an automatic thermostatic control, such as is obtainable in other machines heretofore provided by means of a thermostat controlled or similar device, can be effected with the present system. As the pressure under which the refrigerant evaporates determines the temperature of the evaporation and consequently of the refri rator in which the system is installed, variations in pressure will occur practically coincidently with variations in tem erature, and hence the pressure controlle switch described above will perform the same function as a thermostatic controlling device. This con trol may be rendered more sensitive and uniform by permitting the pressure operated device 25 to actuate a rheostat to vary the moose? amount of current impressed upon the motor 11, so that the speed of the latter may be varied in accordance with the rapidity or extent of temperature changes around the cooling coil. The response of the switch operating means to varying pressure will more truly control temperature in View of the fact that all the active refrigerant is contained at all times within the reservoir, cooling coil and trap, and these elements are all enclosed in thecooling chamber of the refrigerator. Consequently, all the evaporation takes place within these elements and as the pressure operated device 25 is in communication with these elements at the evaporating side of the valve 18, the said device will quickly and truly respond to pressure changes in the system between the compressor and the evaporating surface of the refrigerant. The provision of the vent 21 will permit the escape of any gas or refrigerant vapor into the coil 19, and thus prevent the formation of a so-called gas lock in the reservoir. The proximity of the drop line 16 and valve casing 18 to the cooling coil 19 will ensure the liquefaction of any gaseous refrigerant that may collect in the drop line or' valve casing and thus also prevent the formation therein of a gas lock.

Thus, it will be seen that I have provided a refrigerating system that includes a minimum number of elements. all of which are simple in construction and principle, so that the possibility of errors of adjustment are eliminated and an absolute automatic action assured. It will furthermore be noted that the system, as herein described, is designed to operate at the highest point of efiiciency, since all of the active refrigerant is contained at all times within the cooling or evaporating zone, and owing to the automatic operation of the compressor, gaseous refrigerant is liquefied as soon as formed. Other advantages will readily occur to those familiar with the art to which this invention appertains.

Having thus described my invention, 1 claim:

1. In an automatic refrigerating apparatus, a circulatory system including therein a compressor, a condenser, a reservoir to receive active refrigerant, a cooling coil, :1 float controlled valve to admit liquid refrigerant to the reservoir but to exclude gas, a vent to drain gas accumulating in the reservoir into the cooling coil, and a trap to receive the overflow of active refrigerant from the cooling coil and located thereabove.

2. An automatic refrigerating apparatus, of the flooded type, including a circulatory system, a cooling unit therein comprising a reservoir to receive active refrigerant, a float controlled valve to permit entrance of liquid refrigerant into the reservoir but to exclude gas, a cooling coil located above the resereme? voir and having its intake end extending into the reservoir, and terminating adjacent the bottom thereof, said intake end having a vent near the top wall of thereservoir within the same to drain gas into the coil, and a tank located above the coil and fed therefrom to receive an overflow' of refrig-- erant from the ooil, whereby all of the active refrigerant in the system may be contained at all times in the reservoir and coil, flooding both and partially filling the tank.

In testimony whereof, I have hereunto signed my name at Philadelphia, Pennsylvania this 16th dav of January 1922.

ARTHUR R. EARNSHAW.

Witnesses: Y

J AMES H. BELL, E. L. FULLERTON.

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