US2068333A - Refrigerating apparatus - Google Patents

Description

2 Sheets-Sheet l N E P NU m m Q W "w W N 5 1a NN 4 m. W A F l kfii-H AHPI Jan. 19, 1937. K. w. KRUMMELL REFRIGERATING APPARATUS Filed Nov. 26, 1935 Jan. 19, 1937. K. w. KRUMMELL REFRIGERATING APPARATUS 2 Sheets-Sheet 2 Filed Nov. 26, 1935 INVENT OR.

Patented Jan. 19, 1937 UNITED STATES PATENT OFFICE 8 Claims.

My invention relates to improvements in refrigerating mechanism to be operated on the absorption principle. and employs for that purpose fluid heat, as for instance the waste heat from the exhaust of an internal combustion engine.

For clearness in illustrating the principles of my invention I have shown the same applied to the utilization of the waste gases of an internal combustion engine, thus providing for the refrigeration of food and other products while loaded. in a motor driven vehicle of any kind, such for instance as an automobile, motor truck, motor driven railway car, aeroplane or the like.

Refrigerating mechanism for this purpose is not per se new, but with my invention the same is more simplified and compact, and is made more certain and eflicient in operation.

Generally speaking, I provide an absorbent,

container in which is placed a quantity of suitdriven into the exchanger where itaccumulates in liquid form.

Automatic means, preferably electrically operated, are provided whereby when the liquefied refrigerant accumulates in the predetermined quantity in the exchanger, the heat is cut off from the absorbent container and the latter cooled, thus providing for the return of the refrigerant to the container, as it is evaporated by heat-exchange, and its absorption in the container, and whereby when the quantity of liquid in the exchanger has been diminished by evaporation to the predetermined degree or exhausted, as the case may be, heat is again applied to the absorbent container and the refrigerant is distilled into the exchanger.

Means are provided for actively cooling the absorbent container after each distillation step has been completed.

Means are also provided for controlling the temperatures in the absorbent container to prevent overheating the same.

Other novel features of construction, and also of arrangement of parts will appear from the following description.

In the accompanying drawings, wherein I have illustrated a practical embodiment of the principles of my invention, Fig. 1 is a diagrammatic view showing the apparatus as it is at the completion of the distillation step in the cycle ofioperation, the heat having been cut ofl from the absorbent container to permit reabsorption therein of therefrigerant.

Fig. 2 is a like view showing the apparatus at the completion of the evaporation step, the refrigerant having been reabsorbed and the heat being applied to the absorbent container for the distillation step.

Fig. 3 is a perspective, partially cut away in section showing a developed form of the absorbent container.

Fig. 4 is a like view of a developed form of the heat-exchange tank.

Referring'in detail to Figs. 1 and 2 of the drawings, I represents the source of fluid heat, such, for instance, as an internal combustion engine from which the fluid heat, in such case the waste gases, are led by means of the conduit 2.

3 represents a valve fitting connected by its heat inlet duct 4 with the conduit 2. The fitting is also provided with a cold air inlet duct 5, and a discharge duct 6 which is connected to the escape pipe 1. The fitting is also provided with an outlet duct 8. The fitting is provided with a central valve chamber communicating with all of said ducts, and having mounted therein the movable tubular valve member 9 which, when in one position, that shown in Fig. 1, connects the ducts 5 and 8 and opens the ducts 4 and 6 to intercommunication, but which in its other position, that shown in Fig. 2 closes the inner ends of the ducts Sand 6 and connects the inner ends of the ducts 4 and 8.

The other end of the duct 8 is connected to 'one end of a tubular casing in by a flexible and expansion joint II. The other end of the casing I0 is connected by a similar joint II to the discharge conduit l2.

The intermediate portion of the casing III is expanded radially and has formed or mounted therein the annular container l3 whose central bore provides an open passage between the ends of the casing l0.

The container I3 is filled or partially filled with a suitable absorbent material, such as activated alumina, silica gel or the like.

.The outer end of the exhaust or escape pipe I extends into the conduit l2 and is provided with a nozzle |4 within the conduit which acts as an injector, when the valve is in the position shown in Fig. 1, to produce a suction draft of cold air through the bore of the container l3.

Means are provided for insulating the container l3 from heatradiating from the escape pipe 1. Thus I have shown the adjacent portion of said pipe covered with a sleeve l5 of heat-insulating material.

l8 represents a closed heat-exchange tank, which it will be understood is in close proximity to the food or other products to be refrigerated, or if desired in heat-exchange relation to brine circulating means. Such heat-exchange relationship is not per se the subject matter of the present invention and is therefore not specifically shown nor described, but, however, will be obvious to those acquainted with the general art of refrigeration. The upper portion of the tank is connected by the relatively large capacity duct I! with the interior of the container l3.

The system comprising the container l3, the tank l8 and the duct I1 is. provided with a suitable refrigerant, such as aqua ammonia, sulphur dioxide, carbon dioxide or the like, which is alternately evaporated from its liquid statefrom the tank l8 by heat-exchange and absorbed by the material in the container l3, and then distilled therefrom by the application of fluid heat to said container and is caused to be accumulated in liquid state in the tank I8.

|8 represents a port in the top of the tank l6 closed by a screw plug I! from which a guide frame 2!! depends within the tank to a point adjacent the bottom of the latter.

The bottom of the frame 28 carries a pair of spaced contacts 2| and 22 and adjacent its top the frame carries a second pair of spaced contacts 23 and 24. 25 represents a floatable bridge member, such as a ball, whose movements are guided by said frame and which when the fluid level in the tank is sufliciently low electrically connects the contacts 2| and 22, but which, when the tank is substantially full of liquid, connects the contacts 23 and 24.

The contacts 2| and 23 are both connected by the branched conductor 25 with one of the terminals of a storage battery 21 or other suitable source of electric current.

28 and 29 represent a pair of spaced apart and axially alined solenoids. The contact 22 is connected by the conductor 38 to one end of the coil of the solenoid 28 while the conductor 3| connects the contact 24 with one end of the coil of the solenoid 28. The other ends of the said coils of the solenoids 28 and 28 are'connected by the conductors 32 and 33, respectively, to the end terminals of the tiltable mercury switch 34. The central terminal of the mercury switch is connected by the conductor 35 to the other terminal of the battery 21.

The conductors 26, 38 and 3| pass through the plug l8 and are sealed therein to prevent the escape of refrigerant from the tank.

The solenoids 28 and 28 have a common core rod 35 which is shifted towards the left in the drawings when the contacts 23 and 24 are electrically connected as shown in Fig. 1, and is shifted toward the right when the contacts 2| and 22 are connected, as in Fig. 2, the movements of the rod being limited by the collars 31, which also serve to enlargethe magnetic field.

33 represents a rocking lever sliding pivotal connection intermediate of. its ends to the rod 38 adjacent the center of the latter, as at 38. One end, preferably the longer end of the lever, is fixedly connected to the end of the pivot shaft 48 with which the valve 8 swings, whereby the valve is swung from one position to the other by the longitudinal movement oi. the rod 38.

The other, shorter end of the lever 38, is connected to one end of a second rocking lever 4| in such manner as to be slidable along the latter against the helical spring 42 wound about the second lever between the first lever and the axis of movement of the second lever. The other end of the second lever 4| is pivotally connected to the stem 43 of the switch 34 so that the rocking ofthe lever 4| causes the switch to tilt from its position shown in Fig. l to that shown in Fig. 2 and vice versa. The sliding connection between the levers 38 and 4| and the interdisposition of the spring 42 cause the movements of the switch to be abrupt and to occur near the end of a movement of the lever 4|.

The switch shown is of the mercury type but it will be understood that any reversing switch having suitable operating characteristics may be used.

The operation of my invention, as embodied in the structure shown in the drawings, is as follows:

During the distillation step of the cycle of operation, the valve 8 has been in the position illustrated in Fig. 2, directing the hot waste gases through the bore of the absorbent container I3, causing the refrigerant which has been previously absorbed therein, to be driven ofl and through the duct H to the tank l8- wherein it has accumulated in liquid form. As the level of the liquid rises in the tank IS the ball 25 moves upwardly until it completes the electrical connection between the contacts 23 and 24 and thus completes the circuit through the battery 21 and the coil of the solenoid 28. The energizing of said coil causes the rod 38 to shift from its position shown in Fig. 2 to that shown in Fig. 1, thereby swinging the lever 38 in the direction to shift the valve 8 so that the hot waste gases are allowed to escape through the pipe 1 and cold air is drawn through the bore of the container l3, thus cooling the absorbent container l3 and ending the distillation step.

Thereupon the heat-exchange to which the liquid contents of the tank II are subjected, causes a progressive evaporation of the refrigerant from the tank l6 through the duct |1 into the container |3 wherein the refrigerant now in a gaseous condition, is reabsorbed.

. This movement of the lever 38 also swings the switch 34 so that the connection between the coil of the solenoid 28 and the battery is interrupted and the connection between the coil of the solenoid 28 and thebattery is completed.

As the level,of the liquid in the tank l8 falls and the refrigerant is being absorbed in the container l3, the ball 25 descends until eventually it connects the contacts 2| and 22 and thus completes the circuit through the coil of solenoid 28 and the battery.

This results in moving the rod 35 from its position shown in Fig. 1 to that shown in Fig. 2, thus swinging the lever 38 so that the valve 8 is swung into its position shown in Fig. 2 wherein the hot waste gases are caused to travel through the bore of the container l3, thus heating its contents and causing the previously absorbed refrigerant to be distilled and to pass up the duct 11 again to accumulate in liquid form in the tank l5.

The last mentioned movement of the lever 39 also swings the switch 34 into the position shown in Fig. 2 wherein the coil of the solenoid 29 is connected to the battery 21 through the conductors 33 and 35 and the circuit through the solenoid 28 is broken.

As the liquid accumulates in tank It the ball 25 rises until it connects the contacts 23 and 24 and thus initiates another evaporating step, thus completing a cycle of operation.

To avoid the possibility of overheating the container I3 by the travel through its bore of the hot waste gases, I provide a bellows device 44 having tubular connection 45 with an air chamber 46 mounted in a pocket 41 in the wall of the container l9. As the temperature in the containerrises, the air in the chamber 45 will expand and thus expand the bellows device 44. Likewise the device 44 will contract as the temperature of the container l9 falls.

The device 44 is provided with an abutment 49 alined with the rod 95 and formed 'of nonmagnetic material such as brass.

In case of excessive temperatures in the container l3, the bellows device will expand and push the rod 35 from its position illustrated in Fig.2, thus causing the lever 98 to swing in the proper direction to shift the valve 9 into position to direct the hot waste gases into the escape pipe 1 and to cause cold air to be drawn through the bore of the container. I thus guard against accidental overheating of the container i3.

It is obvious from the foregoing that my invention provides inexpensive refrigerating apparatus of simplified structure which is positive in its operation and which may be built in such light weight and compact form as to occupy but little space in the vehicle and without appreciably increasing the weight of the latter.

Referring now to Fig. 3, I show the absorbent container as comprising an outer casing 49 having contracted openings 50 at its opposite ends for connection to the duct 8 and the conduit M, respectively. The intermediate portion of the casing is enlarged to provide a space for the absorbent container proper 5|. The container is in the form of a box having its outer walls 52 provided with fins 53 which engage the inner walls of the casing 49 and hold the container in position. The fins 53 are disposed longitudinally so as to provide channels for the passage of the waste gases or cold air through the casing. 54 represents tubes extending through the container longitudinally, which provide additional channels for the passage of the waste gases or cold air. The exterior surfaces of the container 5|, and the surfaces of the fins 53 and the walls of the tubes 54 provide surfaces for the conveyance of heat to or from the contents of the container 5|.

The duct I1, which as shown in Figs. 1 and 2 connects the absorbent container with the heatexchange tank, leads down through the top wall of the casing 49 and also the top wall 52 of the container 5| and is connected at its lower end to an inner box 55, which is of smaller capacity than the container 5| and has its walls spaced inwardly therefrom. The walls of the inner box 55 are double and are formed of wire mesh. The inner box is opened at its ends so that the central tubes 54 extend through the same.

The container 5| and the open interior of the inner box 55 are filled with. the absorbent material, which may be activated aluminum or silica gel, which should be of proper granular size so as not to pass through the screening which forms the double walls of the box 55.

The purpose of the inner box is to enable the refrigerant when in gaseous form to be uniformly distributed throughout the silica gel during the absorbing operation. It will be understood that any suitable method of uniformly distributing the gaseous refrigerant throughout the gel may be employed. I

Referring now to Fig. 4, the evaporator H5 is provided with two! compartments 55, one on either side of the frame 25, for the storage of food or other material to be refrigerated, suitable access to said compartments being provided, as, for instance, by the top lids 51. The walls of said container are double, providing a brine space 59 immediately surrounding the compartments 55, and outside of said brine space a refrigerant space 59, in which space I provide the horizontal baffles 60 to prevent surging of the liquid refrigerant. The space 59 surrounds the frame 29 in which the contact ball moves verftically with the level of the liquid refrigerant, and baffles 59 are provided within this surrounding dering the evaporation, and consequently the 11 cooling effect, more uniform throughout the heatexchange areas.

I claim:-

1 In refrigerating apparatus arranged to be operated on the absorption system in connection with a source of fluid heat, the combination with an absorbent chamber, a heat-exchange chamber and a. passage connecting the chambers, of a. duct to which the wall of the absorbent chamber is exposed, a second duct for the escape of the fluid heat, and means for alternately causing the fluid heat to travel through the first duct and heat the absorbent chamber and to cause air to travel through the first duct to cool the chamber and the fluid heat to travel through the second duct.

2. In refrigerating apparatus arranged to be operated on the absorption system in connection with a source of fluid heat, the combination with an absorbent chamber, a heat-exchange chamber and a passage connecting the chambers, of a duct to which-the wall of the absorbent chamber is exposed, a second duct for the escape of the fluid heat, means for alternately causing the fluid heat to travel through the first duct and heat the absorbent chamber and to cause air to travel through the first duct to cool the chamber and the fluid heat to travel through the second duct, and means whereby the travel of the fluid heat through the second duct expedites the travel of air through the first duct.

3. In refrigerating apparatus arranged to be operated on the absorption system in connection with a source of fluid heat, the combination with an absorbent chamber, a. heat-exchange chamber and a passage connecting the chambers, of a duct to which the wall of the absorbent chamber is exposed, a second duct for the escape of the fluid heat, means for alternately causing the fluid heat to travel through the first duct and heat the absorbent chamber and to cause air to travel through the flrst duct to cool the chamber and the fluid heat to travel through the second duct, and means responsive to the temperatures of the absorbent chamber to prevent overheating of the latter. I

4. In refrigerating apparatus arranged to be operated on the absorption system in connection with a source of fluid heat, the combination with an absorbent chamber, a heat-exchange chamber and a passage connecting the chambers, of a duct to which the wall of the absorbent chamber is exposed, a second duct for the escape of a the fluid heat, means for alternately causing the fluid heat to travel through the flrst duct and heat the absorbent chamber and to cause air to travel through the first duct to cool the chamber and the fluid heat to travel through the second duct, and means, responsive to the changes in the quantity of liquid refrigerant in the heatexchange chamber for reversing the operation of the flrst mentioned means.

5. In refrigerating apparatus arranged to be operated on the absorption system in connection with a source of fluid heat, the combination with an absorbent chamber, a heat-exchange chamber and'a passage connecting the chambers, of a duct to which the wall of the absorbent chamber is exposed, a second duct for the escape of the fluid heat, means for alternately causing the fluid heat to travel through the flrst duct and heat the absorbent chamber and to cause air to travel through the first duct to cool the chamber and the fluid heat to travel through the second duct, and means comprising solenoid mechanism aoeassa for reversing the operation of the flrst mentioned means.

6. In refrigerating amiaratus arranged to be operated on the absorption system in connection with a source of fluid heat, the combination with an abmrbent chamber, a heat-exchange chamber and a passage connecting the chambers, of a duct to which the wall of the absorbent chamber is exposed, a second duct for the escape of the fluid heat, means for alternately causing the fluid heat to travel through the first duct and heat the absorbent chamber and to cause air to travel through the flrst duct to cool the chamber and the fluid heat to travel'through the second duct, solenoid mechanism for reversing the operation of the flrst mentioned means, and electrical means responsive to the changing quantity of liquid refrigerant in the heat-exchange chamber for energizing the solenoid mechanism.

7. In a refrigerating unit having an absorber arranged to be intermittently heated and then cooled, the combination of means for alternately directing a stream of hot fluid and then air to said absorber, and means actuated by the stream of hot fluid to expedite the flow of air to said absorber during the period that it is being cooled.

8. In a refrigerating unit having an absorber

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