US1543027A - System of refrigeration - Google Patents

Description

June 23, 1925.

- Filed y 23, 1921' L. PENWELL SYSTEM OF REFRIGERATION 25 Sheets-Sheet 1 June 23, 1925. i,543,27

L. PENWELL SYSTEM OF REFRIGERATION File July 23 1921 s Shets-Sheet 2 IL. PEINWELL SYSTEM OF REFRIGERATION File ly 23, 1921, S SheetS-Sh eet 5 June '23, 1925. 1 1,543,027

Patented June 23, 1925.

UNITED STATES PATENT OFFICE.

LEWIS PENWELL, or

TION 00., or

CHICAGO, ILLINOIS, ASSIGNOR TO A.-B.-C. TRANSIT REFRIGERA- HELENA, MONTANA, A CORPORATION OF DELAWARE.

SYSTEM OF REFRIGERATION.

Application filed July 23, 1921. Serial Ne. 487,089.

To all whom it may] concern:

Be it known that I, LEWIS PENwnLL, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Systems of Refrigeration, of which the following is a specification.

This invention relates broadly to heat ex- 19 change, particularly to refrigerating apparatus, and more specifically to such apparatus whereby the cooling-is effected by circulation of a fluid heat-transfer medium in association with the material which it 1 is desired to preserve. v

The general purpose of the present invention is the provision of apparatus of the above specified sort which may be embodied in a small installation suitable for use in retail shops and the like Where ice cream or other commodities are dispensed, and which is adapted to be operated effectively at small cost and with minimum power requirements.

Another object of the invention is the provision of such apparatus of such simple nature as permits its being operated efficiently without any special skill or technical knowledge on the part of the operator.

Another particular object of the invention is the provision of a refrigerating cabinet for preserving ice cream or similar commodities, and which is designed particularly to facilitating dispensing of the commodities and to prevent contamination thereof by introduction of foreign material inadvertently into the dispensing containers.

Another particular object of the invention is the provision of such apparatus designed to be cooled by ice, in which loss of cooling efiiciency from exposure of the ice to atmosphere is minimized.

Other and further objects of the invention will be pointed out hereinafter, indicated in the appended claims, or obvious upon an understanding of theinvention from the present disclosure.

In the drawings forming a part of this specification I have illustrated two forms in which the invention may be embodied, making said forms the bases of the present disclosure, but it is to be understood that the same are submitted entirely for illustrative purposes and are not to be construed as limiting the invention hereinafter claimed short of its true and mose comprehensive scope in the art, as I am aware that it may be embodied in other fashions.

In the drawings Fig.4 is a top view partly in section of the apparatus in the nature of an ice cream cabinet embodying my invention;

Fig. 2 is a top view of the circulating ap paratns in modified form;

Fig. 3 is a sectional elevation of the form illustrated in Fig. 1 taken substantially on line 83 of said figure Fig. 4 is a transverse sectional elevation through the cabinet and brine tank showing one form of circulating apparaus; and

Fig. 5 is a similar view showing the form of circulating apparatus illustrated in Figs. 1 and 3 and taken on substantially the line 55 of the former.

The invention will best be understood by reference to these illustrations. Let it be understood that the numeral 1 designates generally a cabinet forming an inclosure and housing for the appa ratus and the installation, said housing including a top portion 1 provided with suitable openings with removable closures topermit introduction and removal of containers and dispensing of material therefrom. Within this housing are cooling and circulating means comprising a cooling tank 2 and connected circulating columnar conduit 4.-. The cooling tank and the housing above it are provided with openings joined by suitable thimble 5, through which ice may be introduced into the tank, said openings being closed by suitable heat insulated closures 6.- The circulating conduit illustrated in Figs. 1 and 3 is in thenature of a thin continuous tank- 'like member convoluted to provide receiving space for cylindrical containers 7 and to conformto their contour and afford intimate association. The space between the tank and circulating conduit and the 021s ing is filled with suitable heat insulated material. This circulating conduit, excepting for the connections hereinafter mentioned,' is hermetically closed, and affords a continuous receptacle and circulating channel for the refrigerant. The ends of this circulatingconduit terminate adjacent the cooling tank and have communication therewith at two points, one of said points being at the inlet connection 8 and the other the outlet end thereof, but without affording communication between. the cooling tank and the circulating conduit in such portions of the latter. An intake pipe 11 leads from the inlet connection 8 tothe lower portion of the cooling tank, where it terminates at an open inlet end above the lower level of the outlet connection 9. The cooling tank is divided through part of its height by a partition 12 interposed between the intake end of the pipe 11 and the outlet connection 9. Draw-oil connection 14 communicates with the lower portion of the tank 2, and a vent connection 15 commu nicates with the upper portion of the circulating conduit.

On a bracket 16 supported on the top of the casing is mounted a small motor 17 which drives a pump shaft 18 housed in a tube 19 which projects into the tank 2. In

J the lower end of the tube 19 is carried a pump tube 20 into whichthe pump shaft 18 is led through a packing gland 21. The

pump tube is open at its lower end and within it is a small impeller 22 carried by the pump'shaft 18. The pump tube is arranged in the compartment of the tank with which the outlet connection communicates, and discharges through an outlet 24 across the partition 12 into the compartment of the tank with which the intake tube 11 communicates. Upon operation of the motor 12 the impeller 22 is actuated to function as a small rotary pump whichis effective to lift liquid from the outlet compartment into the inlet compartment of the tank and to maintain a difference of level of liquid in the two.

In the operation of the preferred embodis ment of the cabinet, ice and salt are introduced to the tank 2 with a sufiicient quantity of water to produce a volume of brine adequate to fill the system. An air pump is connected to the vent 15 and suction created thereby to draw the brine into the circulating conduit 4-. The action of the air pump is continued until the conduit 4 is completely filled, which is indicated by the appearance of the brine at the air pump. Obviously as the brine is drawn into the circulating system the level of the same falls in the cooling tank 2, but enough must be retained therein to keep a considerable portion of the pipe 11 immersed. At this stage,

aseaoaa however, the level in the compartments of the tank may be the same and until a differential level is created no circulation of the brine occurs. But this differential is established by operation of the motor 17 and the impeller 22 which lowers the head in the outlet tank and increases the head in the inlet tank. Whereupona syphonic or equalizing flow is induced in the circulating system, which tends to equalize the head in the two compartments-and which consequently continues until the level of the brine in the outlet compartment'reaches the level of that in the inlet compartment. At this time the pump again isstarted to create the differential level or pressure and the syphonic or equalizing circulation again results. The cold brine is drawn through the intake pipe 11 into the upper portion of the inlet end of the circulating conduit, and being colder than the brine in the conduit, tends to lower and equalize the temperature throughout the height of the latter in the course of its circulation longitudinally as well as vertically in the same. This will result in the maintenance of substantially uniform temperature throughout the height of the circulating conduit with the result that the material in the containers will be maintained at substantially uniform temperature throughout its entire depth. While the brine at the discharge end of the con duit will be warmer than that at the inlet end, thiswill not have an undesirable effect upon the material in the cause of the fact that the container subjected to the influence of the warmest brine is also subjected to the influence of the coldest brine. Ihe cross connection pipe 10 forms a channel through which brine may circulate from one end of the conduit to the other end thereof. being subjected in its passage to the influence'of the ice in the tank.

As an alternative to the foregoing the application of the air pump to the vent 15 may be eliminated by supplying a sufficient quantity of brine to the tank 2 to fill the circulating conduit by gravity, leaving the valve of the pipe 15 open to permit escape of the air from the circulating system, then closing said valve and drawing oft" enough .containers, be-

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of the brine from the tank to reduce the above the level of the brine in the outlet tank 2 to an effective level cold brine to enter the circulating compart: ment 4 to take the place of the relatively warm brine which has passed out from that compartment into the outlet compartment of the tank 2, which circulation occurs also during the time the pump 22 is operated. With the re-establishment of corresponding levels ofbrine in the two compartments of the cooling tank the circulation of the brine in the circulating compartment ceases, the cold body. of brine in that'compa'rtment serves to preserve in a cool condition the contents of the containers 7.

In ordinary circumstances the operation of the pump is etfected'approxiinately every fifteen minutes, and the pump operates for a period of approximately one minute. This has been found sufficient to impart circulation to the brine so as to withdraw the relatively warm portion thereof from the circulating compartment land to force into said compartment a sufiicient quantity of the cold brine to take the place of the relatively warm brine Whichdias been withdrawn.- However the operation of the pump may be automatically effected by a thermostatic switch or through time mechanism which will give to the circulation of the brine the periodic impulses above referred In the absence of the automatic control the starting and stoppingof the motor, operation of a hand switch at suitable periods will be resorted to for effecting this change of the brine.

The circulation described is intended to. reach the conditions where thecabinet is in operation through the day, and repeated opening of the same for'access to the contents of the containers exposes the conduit to the atmospheric temperature, thus requiring cooling of the brine more frequently than where the cabinet remains closed for acontinued period, such as at nighttime. In the latter condition, the compartment 4 may be held at the proper temperature, due to the fact that atmospheric temperature does not modify'to any appreciable extent the temperature of the brine in the compartment, and in this condition of the apparatus the brine will remain sufliciently cold for a period of eight or ten hours without circulation, such as is required in day time service.

Apparatus constructed and operated in this fashion will maintain a continuous and uniform circulation of the cooling medium and maintain the material in the containers at the desired temperature so long as ice is kept in the tank. As the circulating medium becomes diluted through melting of the 'ice, a proper amount may be drawn off through the connection 14 and a proper amount of salt or concentrated brine solution added to bring that in thetank and conduit up to the desired strength. a

In the modification illustrated in Fig. 2 the circulating conduit is not convoluted, but is shaped in suitable form to-encompass the containers of rectangular or other form. In Fig. 4 is shown a modified form of the brine circulating means. In this form the tank is not divided into the two compartments for maintaining different levels of liquid, but the circulation is induced by the pumping of the brine from the tank directly into the inlet connection 8, the rotary pump operating Within the intake pipe 11*.

' WVhen designed as a dispensing cabinet, as for ice cream, the invention affords a particularly economical and sanitary installation. The ice is not exposed to the atmosphere incident to the opening of the cabinet for removal of the material, nor is it necessary to keep the containers in ice or water, as they are now customarily; cooled, and the likelihood of such materials finding entrance into the containers is thereby obviated. I

The arrangement furthermore preserves the containers in which thematerial is kept, as they are not subjected to contact of the brine as in cases where the containers are packed directly in salted ice. Interchange of the containers is facilitated, as there is nothing to interfere with their insertion into the receiving space of the circulation jacket and their removal therefrom.

I claim:

1.'A refrigerating apparatus comprising the combination of an insulating receptacle, an enclosed casing located therein providing a columnar passageway, a refrigerant supply vessel located in the insulating receptacle and communicating with said passage-way,

and means for causing a How of the refrigerant through said passage-way and the refrigerant supply vessel.

2. A refrigerating apparatus comprisin the combination of a receptacle, an enclose casing located therein providing a columnar passage way, a refrigerant supply vessel 10- tank whereby a syphonic circulation can I occur through the columnar conduit and the brine tank, and means for inducing the syphonic circulation.

4. A refrigerating apparatus comprising an outer receptacle, a refrigerant supply tank located therein, a columnar conduit 10- cated in the outer receptacle and communicating with said refrigerant supply tank, and a conduit between different levels of the columnar conduit passing through the refrigerant supply vessel whereby heat exchange and circulation of the refrigerant medium is induced.

5. A refrigerating apparatus comprising an outer receptacle, a refrigerant receptacle therein, a columnariconduit communicating with said refrigerant receptacle, said refrigerant receptacle and the columnar-conduit located wholly within and spaced an appreciably wide distance from the side walls of the outer receptacle, insulating material filling said space, and a conduit between difl'erent levels of the columnar consduit passing through the refrigerant supply vessel whereby heat exchange and circulation of the refrigerant medium is induced.

6. In a refrigerating apparatus, the combination with a container of a circulating conduit affording a path for the circulation of liquid about the container, a brine tank adapted to retain a supply of liquid at a lower level than that in the circulating conduit, said brine tank so communicating with the respective terminals of the circulating conduit that a syphonic circulation can occur through the conduit and the brine tank, and means associated with the tank for inducing the syphonic circulation.

7 In arefrigerating apparatus, the combi ment at a higher level than that in the discompartment.

charge 8. n a refrigerating apparatus, the combination with a container, of a conduit for circulating liquid in association with said container, a supply compartment having communication with the upper portion of one terminal of said conduit, a, discharge compartment having communication with the lower portion of the other terminal of said conduit, said conduit and compartments being arranged to retain liquid in the former at a higher level than in the latter, and means for maintaining liquid in one of said compartments at a higher level than in the other compartment.

' In testimony whereof I have hereunto subscribed my name.

LEWIS PEN WELL.

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