US2099382A - Refrigerating apparatus - Google Patents

Description

Ndv. 16, 1937. ZELLH'QEFE-R 2,099,382"

REFRIGERATING APPARATUS Filed Aug. 22, 1955 2 Sheets-Sheet l INVENTOR. GA f/V/V E ZELL HOEFER A TTORNEY.

Nov. 16, 1937. G. F. ZEl LHOEFER 2,099,382

REFRIGERATING APPARATUS Filed Aug. 22, 1935 2 Sheets-Sheet 2 By 7 MW A TTORNE Y.

- Patented Nov. 16, 1937 UNITED STATES "PATENT, .oFFicE 2mm nnmcnnamo mmrus Glenn F. Zellhoefor, Bloomhigton, 111. Application August 2:, ms, Serial No. 31,301

' 1 Claim. (01. se -11's) This invention relates to improvements in refrigerating apparatus and more particularly to that type known as absorption refrigeration.

I The absorption type of refrigerating apparatus includes the employment of a gaseous refrigerant and a liquid solvent therefor. The apparatus includes an absorber in which the refrigerant enters into solution with the solvent: a heater or still in which the refrigerant is boiled .01! or distilled from the solution by the application of heat; a r'ectifler in which the gaseous refrigerant boiling off the solution passes and in which any portion of the solution boiled of?! with the refrigerant is re- I moved and returned to the heater; a condenser II in which the temperature of the gaseous reirlgerant from the rectifier is reduced sufliciently to causethe gaseous refrigerant passing underpressure i'romthe heater to assume the liquid state; a cooling coil in which the liquid gaseous 2o refrigerant from the condenser is allowed to expand underreduced pressure and return to the gaseous state, absorbing heat from the surround ing atmosphere; and means for returning the gaseousrefrigerant from, the cooling coil to the ggabsorber.

In the absorption type refrigerating apparatus of large capacities such as required for redueing I and maintaining'a low temperature in largespaces, and in air conditioning dwellings and so other buildings, it is necessary to regulate the temperatures of the absorber, rectifier, and condenser in accordance with the nature of the refrigerant and solvent employed. These temperatures are usually produced by circulating :5 water through these parts of the apparatus so that by regulating the temperature of the water passing through these pipes, the desired temperai tures for the eflicient operation of the particular unit of the refrigeration apparatus are produced 40 and maintained. In some localities water from the commercial main, termed tap water, is employed for "this purpose, while 'in other localities,

this is not practical and the cooling wateris circulated through a cooling tower so that the temperature of the water leaving the tower will be reduced sumciently to be again circulated through the respective units of the refrigeration apparatus. It is an object of this invention to provide systems for circulating the cooling water through 50 the desired units of the refrigeration apparatus,

irrespectiveof whether the cooled water is received from a water tower, or from the commercial supply, to produce-the most efiicient operation of the refrigerating apparatus inaccord with local 55 conditions. i l

with these and other objects in view, reference is made to the accompanying sheets of drawings,

, which illustrate preferred forms of this invention with the understanding that minor detail changes may be made without departing from the scope 5 thereof. I y

In the drawings:v

Figure 1 is a view, partly diagrammatlcai and. partly in elevation, with parts broken away, illustrating an embodiment of this invention as applied 10 to a refrigeration apparatus as disclosedin this I applicant's prior copending application Serial No.

736,232 of July 10, 1934.

Figure 2 is a view similar to Figure 1, illustratinga modified form of this invention.

The apparatus illustrated in Figure 1 includes an absorber A, a heater or still H, a rectifier R leading therefrom, a condenser C, a cooling coil CC, a heat exchanger E, a solution-collecting chamber 3, a solution-circulating. pump P, a motor M for the circulating pump, and a boiler B for supplying steam to the heater. In the form illustrated, the apparatus is designed to provide conditioned air to an enclosed space or building,

and in addition to the above enumerated elements, includes an air distribution unit AD which draws air in through the inlet I by a motor-driven cir' culating fan F, which circulates the air tobe conditioned over the cooling coil CC, and discharges the conditioned air through the discharge opening D into the space to be air conditioned or into ducts leading therefrom, as the case may be.

The above apparatus is all of commercial form,

and, therefore, a more detailed description is not deemed necessary. However, it may be stated briefly that the operation of such an apparatus in general is as follows: Steam is produced in the boiler B which is conducted by means of the pipes I and I to a radiator, not shown, within the heater H from which the condensate is returned from the pipe 8 to the boiler. The operation of the pump P circulates the solution collecting in the chamber 8 through pipes 4 Q and 6 to be discharged within the heater over the steamheated radiator SR, in which pipe 5 passes through and within the outer coil I of the heat exchanger E. The refrigerant is distilled or boiled of! the solution within the heater H and the solvent is collected in the bottom thereof and passes by the ward the pipe 8, the enlarged '50 coilj'of the heat exchanger, and the pipe 9 leading'from the bottom thereof, to be discharged within the absorber A. The gaseous refrigerant passes through the rectifier R leading from the top of the heater H and through pipe lllto the 5.,

interior of the condenser C. The condensed refrigerant in liquid form passes from the condenser C by pipe H to the upper or high side of the cooling coil CC, the other end or low side of the cooling coil being connected to pipe 12 which returns the gaseous refrigerant and discharges it within the absorber A within which it contacts and is absorbed in the solvent from 'pipe 9 returned from the heater and goes into solution therewith, which solution is collected in the solution chamber S to be again circulated through the apparatus by the pump P.

In the form illustrated in Figure 1, a commercial water tower, which may be such a one as disclosed in this applicant's prior Patent No. 1,950,345, November 6, 1934, is employed, from which water cooled to approximately .F. is led by the pipe l3 directly to the absorber A, and after passing through the coil l4 therein, is led by pipe l5 directly to the condenser coil l6 within the condenser C. The temperature of the water then entering .this coil from the absorber has been raised in passing through the absorber to approximately F., and in passing through the condenser coil 5 will be increased to approximately F. This water of approximately 95 F. is conducted from the condenser coil 16 by the pipe I! to a return pipe I 8 to the water tower, not shown. In this form, the nature of the refrigerant and solvent forming the solution requires a temperature of the water entering the rectifier to be the same as that leaving the condenser for a coil I9 within the rectifier R. Inasmuch as the rectifier does not require the full volume of the water passing through pipe I I, it is, therefore, preferable to by-pass a portion of this water by means of pipe 20 leading from pipe IT and pass it through the coil l9 within the rectifier. The water leaving said coil at approximately F. to F. is conducted by pipe 2| back to the return pipe l8 to the water tower.

As stated in the brief description of the drawings, this invention is illustrated and described as applied to an absorption refrigeration apparatus such as disclosed in this applicants prior copending application Serial No. 736,232, of July 20, 193-4 which has matured into Patent No. 2,061,606, granted Nov. 24, 1936; and as stated in this applicants co-pending application Serial No. 7,662, of February 25, 1935, this particular apparatus is particularly adapted to employ dichloromonofiuorom ethane as the refrigerant and ethyl ether of diethylene glycol acetate as the solvent. The temperatures above given of the cooling water in the respective elements of this apparatusto produce the most eificient operation are those preferably employed when using dichloromonofiueromethane as the refrigerant and ethyl ether of diethylene glycol acetate as the solvent. The length of pipe in the water coils may be varied to meet various conditions of the apparatus and the various chemicals that may be used, and it is so contemplated in this invention.

The characteristics of this refrigeration apparatus are such that it is to an advantage to use the cooled water by the tower in the absorber first because within normal operating range each degree Fahrenheit reduction in temperatureof the solution temperature in the absorber increases the capacity of the refrigeration, machine approximately 2.5%, other factors'being equal, while a reduction of 1 F. in the condenser has very little advantage in addedcapacity of the machine. Hence the water.from the tower enters the absorber first and is then used at approximately 5 higher temperature for condens-. ing the refrigerant in the condenser where its 'highertemperature is not such a disadvantage as it would be for use in the absorber.

All, but preferably a part, of the water from the condenser may be used in the rectifier. It is necessary for the water entering the rectifier to be as warm as the water leaving the condenser to preclude the possibility of condensing out some of the refrigerant vapors, thereby producing a refluxing of the refrigerant and thereby reducing the thermal efliciency of the refrigeration apparatus. On the other hand, due to the low vapor pressure of the solvent, it is possible to remove essentially all of the solvent vapors at relatively high temperatures. Hence the flow of water through the rectifier is so governed by the friction drop through the coil and connecting pipe as to give a temperature to the outgoing rectifier cooling water of 10 to 15 F. higher than the outgoing condenser cooling water, and the cooling surface of the rectifier coil is so portioned as to give a refrigerant temperature of 25 to- 35 F. higher than the. liquid refrigerant in the condenser.

By this method of properly proportioning the cooling surfaces in the absorber, condenser and rectifier, and governing the drop in pressure due to friction of the water through the coils and connecting piping, a most efiicient system of cooling is provided without the use of any control device.

By this method, a temperature rise of 10 to 12 F. to the water is effected in passing through the refrigeration apparatus, which affords the optimum efficiency and economical operation of the water tower and water-circulating equipment.

Figure 2 illustrates a form of this invention that may be employed when cool commercial or tap water is available for circulation to the apparatus.

Tap water is usually of a much lower temperature than that from a cooling tower and is sometimes 65 F. or lower. In the type of refrigeration apparatus disclosed, water at a temperature below 65 F. would be too low to be used to the best advantage in such apparatus. Therefore, in communities where the tap water is be low this degree, it is preferable to provide means for increasing the wate temperature to approximately 65 F. before delivering to the absorber. To accomplish this, the pipe 22 leading from the source of commercial tap water is first passed through a water coil WC placed in the air distributing unit AD between the cooling coil CC and the air circulating fan- F, whereby the air being of a temperature usually above 75 F. is forced by the fan over the water coil WC and the temperature of the water entering the absorber may be controlled to afford a temperature of approximately 65 F. The temperature of the water leaving the absorber A will be increased to approximately 80 F. andis conducted through pipe 23 to the condenser coil in the condenser C. All or part of the water leaving the condenser at approximately 95 F. is lead therefrom by the pipe 24 to the rectifier R and may be controlled by the by-pass valve 25. After passing through the coil of the rectifier, the water is lead by pipe 26 to the sewer. Pipe 26 is preferably provided with a commercial pressure control valve 21 actuated by the pressure within the rectifier R. to control the flow of water through the system.

' ratus including a still, an absorber. a heat exchanger interposed between the still and absorbrectifier into the condenser and then into the What I claim is: he two fluid absorption refrigerating appaer, a rectifier in direct communication with the still, a cooling coil, and a c ondenser interposed between the rectifier and said.v coil, wherein the the heat exchanger into the still where the refrigerant is boiled oil, and passes through the cooling coil and back .to the absorber, a system for circulating cooling'water from a common source through coils in the absorber, condenser and rectifier, wherein the flow is controlled to successively raise the temperature of the water at each step to condense the refrigerant in the condenser at the proper pressure and to condense such of the solvent vapors as may pass over from the still into the rectifier without condens- 10

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