US2181851A - Refrigerating system - Google Patents

Description

Nov. 28, 1939. P. SCH LUMBOHM REFRIGERATING SYSTEM Filed Aug. 9, 1937 Patented Nov. 28, 1939 UNITED STATES REFRIGERATING SYSTEM Peter Schlumbohm, New York, N. Y., assignor, by

direct and mesne assignments, to Propane Development Corporation, New York, N. Y., a corporatlon of Delaware Application August 9, 1937, Serial No. 158,045

2 Claims.

The invention relates to a compression refrigerating system of the type which is driven by a combustion engine.

The invention is illustrated partly in section and partly in perspective by way of example in the Fig. 1 to Fig. 3 of the accompanying drawing.

Fig. 1 shows part of an automobile and illustrates an air conditioned tourist car, the motor of which is combined in one cylinder block with the cylinders of the refrigerant compressor.

Fig. 2 illustrates details of common cylinder block.

Fig. 3 shows valve details of the compressor.

I am aware of the fact that one has combined in one cylinder block the cylinders of a Diesel engine and the cylinders of an ammonia compressor. Such a task is relatively simple as the high compression ratio of the Diesel cylinders is sufllcient for the required ratio of compression for the ammonia compressor. Furthermore, in this case the power side was serving exclusively the power want of the refrigerator compressor, and the refrigeration capacity thus could easily be controlled by controlling the Diesel motor to increase or to decrease the power production.

My invention is to combine the automobile motor of a motor car with the refrigerant compressor of a refrigerating system which may be designed to cool the interior of a touring car or the loading space of a trunk, and it is one purpose of the invention to create an adequate and functionally designed equipment for the process of refrigeration as described in my U. S. A. Patent No. 1,935,749, which consists in evaporating, compressing and condensing a portion of a body of refrigerant, and utilizing another portion of said body of refrigerant to create motive power to effect said evaporation and compression.

The construction of such a compact unit in which the propelling power for the car, the driving power for the compressor and the compression of the refrigerant vapors shall be created and shall be balanced against each other offers several problems which are solved-by my invention.

First-The usual automobile combustion engine has a ratio of compression which would not be sufllcient for the degree of compression as required for the condensation of refrigerant. Following my invention it is nevertheless possible to use the same type of pistons and cylinders for all cylinders of the block by constructing the refrigerant compressor as a multiple stagecompressor with two stages or more.

Second.The lack of a clutch between the engine cylinders and the compressor cylinders makes it a problem to balance the refrigerator side with its rather constant refrigeration job against the unsteadiness of the engine which constantly changes the number of revolutions when the car is driven. I found that the function of-a clutch can be replaced by the provision of a throttle valved by-pass between the suction tube of the compressor and its pressure tube. Following my invention this throttle valve is controlled, by hand or better automatically,

(a) In accordance with the revolutions of the engine,

(b) In accordance with the temperature of the evaporator.

One could provide two separate throttle valves in the same bypass or in two bypasses, each one serving separately the purpose of (a) or (b). However, it is known in the art to superpose two such -functional controlling influences, and it will be sufficient if one and the same throttle valve will be controlled simultaneously by the revolution counter, e. g. a centrifugal regulator, and. by the thermostat or pressurestat of the evaporator. Increasing the revolution of the engine leads to opening the by-pass, so that the capacity of the compressor is reduced. Rising of the temperature in the evaporator above the chosen point leads to narrowing the by-pass, so that the compressor becomes more effective. Following my invention the throttle valve may be completely opened transitorily and preferably by a lever operated from the drivers seat when the engine of the automobile is started. Such a complete opening of the bypass creates a "freewheeling effect of the compressor cylinders, thus facilitating the start of the engine.

Third-It is desirable to arrange the condenser of the refrigerating system also under the hood of the motor car. In order to protect the condenser against the heat developed by the engine, I arrange the compressor cylinders at the front ,end of the cylinder block and I place the conthe engine, I provide two separate cooling systems for the two groups of cylinders within the same cylinder block, so that the compressor cylinders may be kept cooler than the engine cylinders.

These various inventive steps are shown in the Fig. l-Fig. 3. In Fig. 1 the refrigerating system is formed by the evaporator I, the suction tube 2 of the first stage compressor, the pressure tube 3 of the first stage compressor 25 (Fig. 2), by the inter-condenser I, by the suction tube 5 of the second stage compressor (26 in Fig. 2), by the pressure tube 6 of the second stage compressor 26, by the condenser 'l, by the tube 8 which alternatingly leads. liquifled refrigerant from the inter-condenser 4 and from the condenser I back to the evaporator I regulated by pressure valves in the bottom of inter-condenser 4 and condenser I, and by'the expansion valve Ill for the refrigerant entering into the evaporator." Thermostats or pressurestats may complete the refrigerating system.

The condensers 4 and l are placed in the draft of the ventilator behind the radiator.

The evaporator I is surrounded by a mantle H. A blower l2 circulates air from the intake 56, I3 over the cold finned surface of the evaporator and the ducts l4, IS.

A common cylinder head 22 covers all cylinders.

If the system is used for the process as described in U. S. A. Patent No. 1,935,749, the carburetor 2| is constituted by a mixing valve, in which air is mixed with refrigerant, e. g. propane, drawn from the upper part of the condenser 1 by means of a regulating valve ll, the propane serving as fuel for the engine after having served as refrigerant in the refrigerating system. The refilling of the refrigerating system with refrigerant may be effected by connecting a pressure storage tank for propane with the intake valve 9.

The above mentioned by-pass between the suction tube 2 and the pressure tube 6 of the compressor is shown in Fig. 1 as tube I8 with the throttle valve IS. The lever 20 is operating the throttle valve in connection with known technical equipment (not shown) like thermostats, centrifugal regulator or dash board push-button in the various ways as described above functional y.

Fig. 2 illustrates the arrangement of the two refrigerant compressors 25, 26 on the same crankshaft 2'! with the engine cylinders 24. The cranks 30, 29 are oflset 180 and are balanced against each other independently of the offset of cranks 28 of the engine. A separate water cooling system 3| is provided for the compressor cylinders and a separate one 32 for the engine cylinders. .The water in the system 3| is circulated by an additional water circulating pump 23 (Fig. 1).

' In Fig. 3 a cross section through one compressor cylinder illustrates details of the intake valve 33 and the outlet valve 34 as built into the cylinder head 22 instead of the spark plugs as is usual for the engine cylinders. Furthermore, the smaller cylinder clearance required for the efllciency of the compressor cylinder is established by the plane form of the cylinder head as illustrated in Fig. 2 and Fig. 3, contrasting with the form of the cylinder head 22 topping the engine cylinder 24 in Fig. 3.

Having now described the nature of my invention and having indicated by way of example the manner in which it is to be performed,

What I claim is: l. The combination, with a vehicle having an enclosed compartment, ofa multicylinder ex-.

pansible chamber structure and means cooperating with said structure to form a refrigerating system and a power plant for propelling said vehicle and actuating said refrigerating system; said system including an evaporator, adapted to cool said compartment, and a condenser; means so connecting certain of said cylinders to said evaporator and condenser that such cylinders may serve as a. compressor to withdraw refrigerant vapor from said evaporator and to compress same so that it may be condensed in said condenser; and intake meansand exhaust means connected to the rest 'of said cylinders for respectively supplying fuel thereto and withdrawing the products of combustion therefrom.

2. Thecombination 'set forth in claim 1 in which a by-pass is provided between the suction and the high pressure side of the compressor and a throttle valve controls said by-pass and the ratio of compression.

v PETER SCHLUMIBOHM.

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