US1893277A - Apparatus for controlling temperature - Google Patents

Description

Jan. 3, 1933. w. EGGLESTON 1,893,277

APPARATUS FOR CONTROLLING TEMPERATURE I Filed March 19, 1950 anvwwoz Patented Jan. 3, 1933 UNITED STATES PATENT OFFICE' LEWIS W. EGGLESTON, OF DETROIT, MICHIGAN, ASSIGNOB TO AMERICAN RADIATOR COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY APPARATUS CONTROLLING TEMPERATURE Application filed March 19, 1930. Serial No. 437,034.

My invention relates to new and useful improvements in a method and apparatus for controlling or regulating the temperature of a space to be refrigerated or cooled.

An object of my invention is' to provide a method of controlling the refrigerating effect produced by the change of state of a body of refrigerant medium and by which it is commercially possible to maintain the sensible heat of a space to be refrigerated accurately at a predetermined temperature, or accurately between predetermined temperature limits.

Another object is to provide an apparatus for performing my novel'method.

The invention consists in the method and the apparatus for effecting the same, to be more fully described hereinafter and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawing, to be taken as a part of this specification, I have fully and clearly illustrated a preferred embodiment of an apparatus for carrying out my novel method, in which drawing- Figure 1 is a view in front elevation with the refrigerant containing chamber closure member or door removed, and showing a temperature responsive element in vertical com tral section, and

Fig. 2 is a view in vertical central section on the line 2-2 of Fig. 1, but with the door or closure member in place.

Referring to the drawing by characters of reference, 1 designates generally a hollow casing or container member, preferably heat insulated and having an internal refrigerant medium receiving chamber 2. The member 1 is preferably rectangular, having substantially solid top, bottom, side and back walls 3, 4, 5 and 6, respectively, and having an open front provided with V a removable closure member or door 7 which may be hinged to the member 1. The walls are preferably of laminated construction, such that the member 1 comprises a frame 8, preferably of solid wood, which is encased and sealed in a tin or other light weight metal jacket 9, and which is lined and externally covered with a heat insulating material '10, such as cork, or the dimension to fit within the wood frame 8, as

in Fig. 2. Within the chamber 2 is a refrigerant medium supporting frame of platform 15, comprising cross-members 16 seated at their ends on base members 17-, which in turn rest. on the cork lining 10 ofthe bottom wall 4. The member 1 is provided with upper and lower or inlet and outlet flow openings or passages 18, 19, respectively, which preferably open through the top and bottom walls 3, 4. he top or upper opening 18 is provided with an upwardly extending conduit member 20, which may be integral with the jacket 9, but which is preferably separate and sealed thereto by soldering, welding, or the like. Cooperating with and adapted to seat on the top end of the conduit member 20 1s a valve member or damper'21, preferably a metal disc, the purpose of which will be described hereinafter. The top wall opening 18 preferably is of stepped construction, the frame 8 and lining 10 being eliminated for an area around the conduit member 20 (see Fig. 2), so that the temperature of member 20 will not drop so low as to cause freezing of valve member 21 to member 20. The lower or bottom opening has a depending conduit member 22 which may be integral with the jacket 9, but which is preferably separate and sealed thereto, as is member 20. The container or casin member 1 may be supported in any suita 1e manner, as, for example, by legs or columns 23.

Positioned beneath the member 1 is a heat insulated container or chamber member 24 which is open at its top and which is preferably substantially rectan lar. The member 24 preferably has laminated side walls comprising layers of wood, tin or other suitable light weight metal, and sheet cork or other insulating material, which are desig nated respectively 25, 26, and 27. The bottom wall 28 of member 24 is preferably of two layers, the inner one 29 being of wood and the outer one 30 being of sheet cork, or the like, so that the open-topped chamber 31 of member 24 is encased in a jacket of cork or other insulating material. Through the bottom wall 28 is a drain outlet 32, preferably formed by a vertical tube of small internal diameter and supported in the wall 28. The container member 24 is positioned at the proper height to cause the depending conduit member 22 to extend partially thereinto, and is of an internal cross area such that the member 22 is well spaced from the side walls of member 24 to provide the necessary flow area between the exterior of the conduit member 22 and the side walls of member 24, as at 31'. The telescoping laterally spaced members 22 and 24 comprise a trap for a purpose to be described.

Supported rigidly by the top wall 3 is a bracket member 33 which pro ects laterally beyond one of the sidewalls 5 and which has at its free end an upwardly extending arm 34 provided with horizontally spaced ears or lugs 35 extended toward and slightly above the. level of the valve member 21. Positioned between lugs 35 is one end of a lever arm or member 36 fulcrumed on a pin 37 passed therethrough and through lugs 35, so that the member 36 is vertically movable. Fixed to the top face of the valve member 21 substantially at its center, is a bracket 38, preferably U- haped, which receives the free end of lever member 36. Through alined apertures in the bracket 38 and member 36 is a pin 39 which secures the valve member 21 to the lever arm 36. Fixed to and depending from the arm 36 adjacent its fulcrum is a bearing member 40 having in its underface a bearing recess 41 which is preferably substantially conical. Depending from the bracket member 33 and spaced laterally substantially equally from member 40, are depending rigid supporting rods or members 42. Secured to and supported by the rods 42 is a temperature responsive means or thermostat 43, comp'rising a casing 43*, within which and hermetically sealing the same is a resilient metal bellows 44 forming an expansion chamber 45 containing a temperature responsive liquid, such, for example, as methylchloride. Carried by and movable with the head 46 of the bellows 44 is a push-rod 47 which extends upwardly through the bellows i 44 and a guide opening in the bracket member 33 and into engagement with the bearing member 40. The upper free end of rod 47 is preferably pointed for cooperation with the conical socket or recess 41. The automatic power element 43 and its push-rod 47 may be steadied against lateral movement by a bracket member 48 engagin one of rods 42 and fixed to the casing side wa l 5. The lever arm 36 is preferably provided with a weight member 49 having a set screw 50, or the like, and being adjustable longitudinally therealong to regulate the response of the thermostat 43 and therefore the opening and closing movement of the valve member 21.

The method of controlling the refrigerating effect produced by the change of state of a mass of refrigerant medium and the operation of the above described apparatus for performing the method, are as follows: The above described apparatus is preferably positioned within an enclosed space to be cooled or refrigerated, such, for example, as a railway refrigerator car, a cold storage room, or a domestic ice box, though it may be operatively connected to the enclosed space by conduits leading therefrom to the upper and lower flow openings. The thermostat control weight 49 is adjusted on arm 36 to govern the response of the element 43 so that the enclosed space will be maintained at or within predetermined temperature limits. The door 7 is removed or opened and a body or mass of refrigerant medium, designated 51, is placed within the chamber 2 on the support 15. The refrigerant medium may be a solid, as carbon dioxide ice, which is the medium preferably employed, or may be a liquid, that is, a liquefied gas, such as liquid air or liquid nitrogen, for example, carried in a suitable container. The refrigerant medium having been placed within chamber 2, the door 7 is tightly closed. Assuming that the air or gas in the enclosed space to be refrigerated is at a temperature above that desired, the thermostat 43 will be expanded so that the valve member 21 will be open and the temperature within the chamber 2 will be above that of the refrigerant medium. Due to this state of facts, the refrigerant medium will absorb heat from the gas or air within chamber 2, changing the physical state of the medium. The refrigerated or cooled gas within chamber 2 being heavier or of greater density than the gas in the enclosed space, will pass or drop downward through opening 19 into the trap or chamber 31, thus drawing higher temperature air or gas from the enclosed space into the top of the chamber through the open inlet opening 18, and thus continuing to supply chamber 31 which will overflow through space 31 into the enclosed space to be refrigerated. There will thus be set up a circulationv of convection gas currents which enter chamber 2 through the opening 18 from the enclosed space, pass downward in heat absorbing relation to the refrigerant medium 51, issue from the opening 19, and pass through space 31 back into the enclosed space to be refrigerated. As the temperature in the enclosed space drops toward the desired temperature, the thermostat 43 will permit movement of valve member 21 toward closed position, thus automatically decreasing the admission of higher temperature air or gas from the enclosed space to the chamber 2 and so decreasing the rate of change of physical state of the medium 51, resulting in decreasing the refrigerating effect produced by the apparatus. When the temperature of the air or gas in the enclosed space has reached the predetermined low temperature desired, the thermostat 43 will have caused tight closing of the valve member 21 so that further entrance of convection gas currents through opening 18 is entirely stopped. The possibility of the valve member 21 freezing fast to the conduit member 20 during this closed period of valve member 21, is efiectively overcome by the stepped construction of passage 18 above described. With the inlet opening 18 tightly closed, it would seem that no further change of state of the medium '51 would take p 1ace, but I have found that closing of the inlet flow opening 18, when the trap or chamber 31 is not employed, does not in fact stop the change of state of medium 51, which therefore results in the temperature of the enclosed space decreasing below the desired low limit. The trap or chamber 31 effectively halts further change of state of the medium 51 by maintaining within chamber 31 and about the outlet opening 19, an atmosphere or body of refrigerated gas which is substantially at the temperature of the gas within chamber 2. Since the body of 1 refrigerated gas in chamber 31 is of a greater density than that of the enclosed chamberto be refrigerated, the refrigerated gas will pocket in chamber 31 and seal the outlet 19.

This seal of refrigerated gas about the outlet 19 prevents recirculation of gas about the medium 51 from the enclosed refrigerated space into and from the outlet 19, which I have discovered would occur save for the maintenance of a body of refrigerated gas about the outlet 19. I have also found that closing of the outlet opening 19 by valve means is impracticable, as the very low temperature thereat will cause deposited moisture from the refrigerated gas or air of the enclosed space to freeze, thus rendering inoperative mechanical valve devices having moving parts. The drain pipe 32 serves to carry off any moisture which may collect within chamber 31. and maintains the trap substantially dry.

. What I claim and desire to's ecure by Letters Patent of the United States is 1. A device of the character described, comprising an insulated chamber having upper and lower flow openings for the circulation of convection gas currents through said chamber and adapted to contain a body of refrigerantmedium, means to close said upper in said trap.

flow opening operable to maintain about said" lower flow openmg an atmosphere of refrigerated gas whereby to prevent flow of gas into and from said chamber through said lower opening.

3. A device of the character described, con1- prising an insulated chamber having upper and lower flow openings for the circulation of convection gas currents through said chamber and adapted to contain a body of refrigerant medium, means to close said upper flow opening, a trap for said lower flow opening operable to maintain about said lower flow opening an atmosphere of refrigerated gas whereby to prevent flow of gas into and from said chamber through said lower opening, and means to 4. A device of the character described, comprising an insulated chamber having upper and lower flow openings for the circulation of convection gas currents through said chamber and adapted to contain a body of refrigerant medium, means operable to close said upper flow o ening and responsive to temperature of re rigerated gas external to said chamber, and means at said lower flow opening operable to maintain about said lower flow opening an atmosphere of refrigerated gas whereby to prevent flow of gas into and from said chamber through said lower opening.

5. A device of the character described, comprising an insulated chamber adapted to contain a body of refrigerant medium and havopening, a conduit mem er depending from the bottom wall of said chamber and opening therethrough into said chamber, and means to maintain an at gas about the discharge end of said depending conduit member.

6. A device of the character described, comprising an insulated chamber. adapted to contain a body of refrigerant medium and having an upper flow opening, automatic means to close said opening, a conduit member depending from the bottom wall of said chamber and opening therethrough into said chamber, and means to maintain an atmosphere of refri erated gas about the discharge end of said epending conduit member.

prevent liquid from collecting mosphere of refrigerated 7. A device of the character described,

comprising an insulated chamber adapted to contain a body of refrigerant medium and having an upper flow opening, temperature responsive means to close said opening, a conduit member depending from the bottom ,wall of said chamber and opening therehaving an upper flow opening, means to close said opening, a conduit member depending from the bottom wall of said chamber and opening therethrough into said chamber, and

' an open-topped chamber positioned beneath said insulated chamber and into which said conduit member depends to maintain an atmosphere of refrigerated gas about the discharge end of said depending conduit mem- 9. A device of the character described, comprisin an insulated chamber adapted to contain a body of refrigerant medium and having an upper flow opening, means to close said opening, a conduit member depending from the bottom wall of said chamber and opening therethrough into said chamber, means to maintain an atmosphere of refrigerated gas about the dischargeend of said; depending conduit member, and means to' prevent sealing of said conduit member by liquid.

10. A device of the character described, comprising an insulated chamber adapted to contain a body of refrigerant medium and having an upper flow opening, means to close said opening, a conduit member depending from the bottom wall of said chamber and opening therethrough into said chamber, and means to maintain a body of refrigerated gas about the discharge end of said depending conduit member, the body of refrigerated gas being the sole sealing means for said conduit member whereby recirculation through said conduit member is prevented when said upper opening is closed.

11. A device of the character described, comprising a, heat insulated chamber adapted to contain a body of refrigerant medium and having openings through its top and bottom walls, a lever member having a fulcrum support, valve means carried by said lever member and operable to control flow through said top wall opening, temperature responsive means engaging said lever to operate said valve means, a conduit member extending downward from said bottom wall opening, and a container having an open top and positioned beneath said chamber, said conduit member depending into said container in,

spaced relation to the walls thereof.

12. A device of the character described, comprising a heat insulated chamber adapted to contain a bodyof refrigerant medium and having openings through its top and bottom walls, a lever member having a fulcrum support, valve means carried by said lever member and operable to control flow through said top wall opening, temperature responsive means engaging said lever to operate said valve means, a conduit member extending downward from said bottom wall opening, a container having an open top and positioned beneath said chamber, said conduit member depending into said container in spaced relation to the walls thereof, and a drain outlet for said container to drain liquid therefrom.

13'. A device of the character described, comprising a heat insulated chamber adapted to contain a body of refrigerant medium and having openings through its top and bottom walls, a lever member having a fulcrum support, valve means carried by said lever member and operable to control flow through said top wall opening, temperature responsive means engaging said lever to operate said valve means, a conduit member extending downward from said bottom wall opening, and a heat insulated container having an open top and positioned beneath said chamber, said conduit member depending into said container in spaced relation to the walls thereof.

In testimony whereof I have hereunto signed my name this 18th day of March, 1930.

LEWIS W. EGGLESTON.

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