US2496189A - Refrigerator car - Google Patents

Description

Jan. 31, 1950 B. E. WILLIAMS REFRIGERATOR CAR Filed April 3, 1947 1 Y lling s frm/zn for ever// E WIV/fmes #crzzecz/ Patented Jan. 3l,

UNiTEDsTATEs PATENT orticav nnmmsnaron can Beverly E. Williams. Chicago. lll. Application April 3, 1941, serial No. 739,155

(ci. cs2-19)V l Claims. This invention relates to a refrigerated wall construction. and more particularly to a structural unit for a heat exchanging wall of such design that a plurality of the units may be assembled in side-by-side relationship to lprovide improved temperature control means. The invention is especially applicable to refrigerated transportation means such as Y railroad cars. trucks and trailers, portable transit or lift vans, airplane fuselages, and the like.

It is an object of this invention to provide a structural unit adapted for quick assembly' in such transportation means for controlling the temperature.

It is another object of this invention to provide an improved heat exchange means for such transportation means.

It is a further object of this invention to provide a structural unit which may be used to convert a conventional railroad car into an eiiicient refrigerator car.

It is a further object of this invention to provide an improved dual purpose refrigerating and insulating means.

It is a still further object of this invention to provide a novel means for quickly repairing the insulating and refrigerating means within a refrigerated transportation means, which may have become damaged in use or impaired in efficiency, by making readily possible the replacement of damaged sections.

Other objects of the invention will appear from the specication below.

In the past it has been the practice to provide refrigerator cars with cooling bunkers containing a mixture of ice and salt which melts at a temperature lower than +32 F. and cools a heat exchange surface over which the air from the interior of the car is circulated. These bunkers are usually provided at each end of the car, and on account of the limited area of the heat exchange surface of the bunkers these surfaces must necessarily be maintained at temperatures considerably colder than the temperatures desired for keeping perishable products within the car. Because of this, the air circulating over the cold bunker surfaces is dehydrated by condensation and freezing of its moisture on the cold surface and when the dry cold air is circulated over the stored product, it absorbs further moisture from and desiccates food and such products in the storage space. Thus a continuous transfer of moisture or drying cycle is set up by reason of the continuous deposition of the moisture upon the colder areas.

Another defect inherent in this older type of refrigerated transportation means resides in the wide difference between the bunker temperature Vand the air temperatures adjacent the bunkers and at the middle ot the car which results in product becoming frozen at the bunker ends while similar product may deteriorate or actually spoil in the middle of the car because it is not cold enough. Also the wide temperature diierence which must be produced between the air and the cold surface causes considerable stratification of air in layers so that the air is cold next to the floor but much warmer next to the top. This condition further contributes to loss of product quality en route.

These many deflciences of the conventional bunker car have long been appreciated but, until quite recently, it has always been considered the most practical transporting means available for perishable products.

Today, however, an improved refrigerator car structure has been provided, and such means is disclosed in the recent United States Patent 2,381,796, granted to Beverly E. Williams on August 7, 1945. As shown in the patent, the entire inner wall surface of the car is divided into channels for circulating a heat exchange medium, and the inner walls of these channels which substantially surround the product on all sides serve as a heat exchanging surface for cooling the air circulating in the car so that the air need not be cooled drastically at localized points in order to maintain a low average temperature throughout the body of the car. This narrowing of the temperature differential between the product, the air in the car, and the heat exchange surfaces reduces the drying out of the air and conscquently substantially eliminates dehydration of product or shrinkage. Moreover, the car can be refrigerated by circulating a refrigerating fluid through the channels which cover substantially all of the side walls of the car, which channels can then be vacuumized to serve as an additional insulating means whereby the lading is stored under the most efficient conditions throughout the trip. The advantages of this structure are fully described in the above mentioned patent.

The present invention has a dual purpose to provide r`st, a novel means such that old style refrigerator cars, i. e. the conventional freight cars, can be converted into refrigerator cars of the type of the above patent, and second to provide means whereby such converted cars and newly built cars as well, may have their refrigerating means more easily and rapidly serviced, repaired, or replaced sectionally.

A preferred form of this invention is shown in the drawings, wherein Figure 1 is a sectional side elevation of a railroad car having walls constructed after the manner of this invention; and

Figure 2 is a perspective view of the car shown in Figure 1, looking from an end, and

Figure 3 is a view taken on line 3--3 of Figurea.

Briefly. the present invention provides a pluralityV of like structural units 'which may be quickly installed in a transporting means whereby the inside wall of the means can be lined with lindividual heat exchange units, all of which are interfitted so that their exposed surfaces form a substantially continuous inside wall therefor. The heat exchange units are designed to be connected to a supply header at one end, usually the top, and an exhaust header at the other end, usually the bottom, so that a heat exchange medium may be passed through each of the units. The units are constructed to be all alike or of standard types so that one may be substituted for another, and one or more may be withdrawn for repair or servicing without disturbing the remaining units installed in the transporting means. Further, the standard units may be constructed to be of such shape or design that/they may be readily installed in any car, trailer, van,

v truck, standard railroad car construction or the like so that an existing means having no insulation at all may be quickly converted to the newer, more efficient type of portable refrigerator means.

Although the invention is intended principally for refrigeration, it will be understood that it can be used also for heating as, for example, when the outside temperature is below that desired to be maintained in the transporting means.

This invention has a particular utility in the railroad refrigerator car field as shown in the drawings and, basically, the new unit structure takes the form of a fluid-tight passageway I0, which is adapted to be connected at the top by inlet means Il to a supply header I2 so that a heat exchange liquid or gas may be driven into or circulated through the flow passage. On its underside the passage is connected through an outlet I3 to an exhaust 'header i4 so that the heat exchange medium may be passed out of the flow passage after doing its work.

The passageway l may be constructed of metal or any other suitable material so as to be fluid-tight, and preferably each flow passage is adhesively bonded by a layer of asphalt I5 to a suitable framework I6 formed of plywood and which is fixed to the wall of the car. As shown in Figure 2, the framework may cover the bottom and substantially all of the rear wall of the chamber l0, the asphalt sealing layer I5 and the frame forming a seat for the unit l0 which seat has a relatively low heat transfer characteristic.

The unit may be made of a size to extend substantially from the floor of the car up to the ceiling and if desired to curve toward the center of the car'adjacent the ceiling in a manner to be easily connected to header I2 running lengthwise along the top of the car. Where a maximum of heat exchange surface is desired, the unit may be so designed as to fit inside the car structure to cover substantially all of the wall area including most of the ceiling and floor. If theunit is being built into a new car particularly provided for this structure, the unit is preferably formed to lie in a ywide sweeping curve from the top center yheader downwardly across the side wall of the car and ending at the floor line; however, the uid flow passage may in some cases be extended across the floor of the car to meet the longitudinal header I4 built into the fioor of the car. The invention thus may nd embod iment in a structural unit of many possible shapes and sizes depending upon the type and size of transporting means for which it is adapted. The essence of the invention resides not in shape or size but in providing a plurality of standard units, which are a'llinterchangeable, for use in a given transporting means.

Each of the standard units, as best shown in Figure 3, has a bank of louvers fixed in front of the inwardly facing surface thereof, but spaced slightly from the exposed face of the unit. These louvers preferably form an integral part of the unit and are provided for the purposes of holding material stored in the car away from the face of the chamber and aiding in the distribution of air through the lading storage space.

To better serve this last function, the upper half sections 20 of the louvers are disposed with respect to the air flow in the car so that the warm air owing toward the cooling surface is directed downwardly onto the cold face of the heat exchange unit and as it is cooled and continues to drop downwardly, the air is directed outwardly into the storage compartment. The louvers are spaced somewhat from the heat exchange surface in order to provide an air passage for free circulation of the air over the cooling surface whereby, to alleviate as much as possible the temperature difference between the air of the interior of the car and the temperature of the cooling surface by reason of the large volume of air in circulation. A further advantage which is realized because of this closer adjustment of the temperature differential is found in the lessening of the tendency of condensing out or freezing out of moisture in the air onto the cold inner wall surfaces.

The louvers are constructed so heavily as to prevent the stored material from jamming into the face of the chamber or passage. This prevents the unit from being damaged and ensures that the air circulation passage is always free.

The individual units are of a Width to provide a convenient flow channel for receiving a refrigerating or heating medium, such as a liquid or gas, and the units are designed to be closely intertted side by side so that substantially the entire inner wall surface of the car may be covered.

Any suitable heat exchange medium can be used for circulation through the units. Liquids of the type of tetra-aryl silicates disclosed in United States Patent 2,335,012, dated November 23, 1943, to Lotte H. Johnston, are very useful mediums for either heating or cooling because of their extremely favorable heat transfer rates. Also, tetra-cresylsilicate, for example. remains fluid and at almost constant viscosity from below zero F. to 750 above zero F. Other fluids, such as salt brine, calcium chloride, brine, nontoxic gases such as carbon dioxide, or other commercial refrigerants such as anhydrous ammonia, Freon, and methyl chloride may be used. If a gas such a `carbon dioxide is used, it may be left in the chamber for its insulating value, which is roughly about twice that of air, or it may be exhausted and the chamber or passageway vacuumized to approach the most efficient insulation possible.

In using the device above described, if the unit is to be installed in an existing railroad refrigerator car structure, the inner soft wall insulation may be partially removed, leaving only the outer layer of approximately 2-inch thick insulation. If the ordinary railway freight car, having no insulation at all, is to be equipped with these units, to convert it quickly, efficiently and economically to a refrigerator car, the plywood seats IB of the units are mounted so as to be spaced inwardly about 2 inches in from the outside walls of the car, and the 2-inch space is filled with a good, easily applied soft insulation material such as loose vermiculite, fibre glass, or other inert insulation material. The refrigerant chambers or units are made secure with the wall by fastening them to the wall structure in any suitable manner. 'I'he heat exchange surface of each unit thus lies parallel with the side wall structure, and the chamber may extend inwardly from the sides toward the middle line of the car at its top or bottom ends, there to be joined to the inlet and outlet headers. After the body structure of the car has been made ready, the supply header l2 is built into and along the ceiling and the exhaust header i4 is disposed along the oor level. Thereafter, the standard units are connected to the supply and exhaust headers. Thus the units substantially cover the side Wall surface and as much of the ceiling and iioor as is deemed necessary to provide the required heat exchange surface. A suitable pumping means may be connected to the exhaust header I4 so that after the car has been refrigerated, or heated if the outside ambient temperature is lower than the temperature desired within the car, the flow passage units may be evacuated or vacuumized to increase the insulating qualities of the wall, ceiling and floor as fully disclosed in my prior above mentioned patent.

If the units are being installed in a new car designed along the principles of that disclosed in said patent, the units form the individual ow passages of the wall of that car and of course the chambers or units must be shaped to the curvature of the more streamlined pattern of such transporting means.

Whether built into an old car or designed for a new one, the louver means of course are provided and are preferably iixedly secured in front of each of the associated chambers i0 from support means that are integral with the flow passage units. In some instances, it may be found desirable to build a bank of louvers into a car so that the heat exchange units may be mounted behind them. The air circulating functions of the upper and lower'halves of the louver bank which is spaced from the heat exchange surface would be served as well as the protection of the units from the abuses of shifting lading. With such a structure, an improved refrigerating car structure is made available wherein all of the benefits of the new structure disclosed in myearlier patent are obtained, together with the additional serviceability and interchangeable features, its adaptability to old or new car bodies. and ease of construction inherent in the present structural unit means.

The invention is described above in connection with railroad car bodies, but it is equally Well adapted to the iield of motor transport or air transport, as it may be built into truck or trailer bodies, airplane fuselages, and also portable units such as transit or individual portable vans that are capable of being transported by rail, truck, airplane or boat. The term transportation means as used in the appended claims is to be understood to include all such applications of the invention.

It is apparent that many modifications of the above examples may occur to those skilled in the art which will fall within the scope of the following claims.

Iclaim:

1. A structural unit providing a means adapted for quick assembly in a railroad car and the like comprising a means forming a flow passage for .a heat exchange medium, said passage means having an exposed heat exchanging face, means to connect the passage means to a heat exchange medium supply header, means to connect the passage to an exhaust header, and louver means supported integrally with said passage means but spaced from its exposed face to hold stored product away from the heat exchanging face and to control the circulation of air between said face and the stored product, said passage means being of a size and shape to fit into a railroad car or the like so that it may be connected to` said supply and exhaust headers in order to a wall surface which assists in controlling the uernperature of the atmosphere in the storage compartment.

2. A structural unit providing a means adapted for quick assembly in a railroad car and the like comprising a supporting frame, said frame being made of non-heat conductive materials, means forming a flow passage for a heat exchange medium, said passage means being mounted in said frame and having an expcsed heat exchanging face, means to connect the passage means to a heat exchange medium supply header, means to connect the passage to an exhaust header, and louver means supported integrally with said frame and passage means but spaced from said exposed face to hold stored product away from the heat exchanging face and to control the circulation of air between said face and the stored product, said passage means being of a size and shape to lit into a railroad car or the like so that it may be connected to said supply and exhaust headers to form a wall surface which assists in controlling the temperature of the atmosphere in the storage compartment.

3. A structure for a body of a transportation means, said means including a. supply header for a heat exchange medium, and an exhaust header for said medium, and comprising a wall structure made up at least in part of a plurality of separate heat exchange units, each of said units being removably connected between said headers, each of said units including a ilow passage for the medium, each of said units having an exposed heat exchanging face, said units being arranged in side by side relationship and together forming a substantial part of the inner wall for the storage compartment of said body. Y and said units being operative by circulation of a heat exchange medium therethrough to control the temperature of the atmosphere in the storage zone.

4. A structure for a body of a, transportation means, said means including a supply header for a heat exchange medium, and an exhaust header for said medium, and comprising a wall structure made up at least in part of a plurality of separate heat exchange units, each of said units being removably connected between said headers,

each of said units including a iiow passage for the medium. each of said units having an exposed heat exchanging face, and each of said units having louver means supported in front of but spaced from the exposed face, said louver means being made up in an upper and lower section wherein the louvers slant in different directions to encourage the circulation of air to and from the exposed face,.said units being arranged in sideby-side relationship and together forming a substantially continuous inner wall layer for the storage compartment of said body, and said units being operative by circulation of a heat exchange medium therethrough to control the temperature of the atmosphere in the storage 5. A standard structural unit for use in association with the storage compartment of a transportation means having walls to support a. heat exchange supply header and an exhaust header for said medium; said unit being adapted to be assembled in said means, between said headers, and along with others of said units to form a substantial part of the inner wall surface surrounding said compartment; comprising a chamber to receive the heat exchange medium;l means to connect said chamber to each of said headers; said chamber being of a size and shape to be removably affixed against at least one of the walls of said means with one face of the chamber exposed to the storage compartment; and louver means fixedly supported from means integral with the chamber the louver means being positioned in front of but spaced from said exposed face.

6. A structure for a body of a transportation means, said means including a supply header for a heat exchange medium, and an exhaust header for said medium, and comprising a wall structure having an outer insulated layer and an inner layer made up at least in part of aV plurality of separate heat exchange units, each of said units being separately and removably connected between said headers, each of said units including a flow passage for the medium. each of said units having an exposed heat exchanging face, said units being arranged in side by side relationship and together forming a substantial part of the inner wall for the storage compartment of said body, and said units being operative by circulation of a heat exchange medium therethrough to control the temperature of the atmosphere in the storage zone.

7. A structure for a-body of a transportation means, said means including a supply header for a heat exchange medium, and an exhaust header for said medium, and comprising a wall structure having an outer insulated layer and an inner layer made up at least in part of a plurality of separate heat exchange units, each of said units being removably connected between said headers, each of said units including a flow passage for the medium, each of said units having an exposed heat exchanging face, said units being arranged in side by side relationship and together forming a substantial part of the inner wall for the storage compartment of said body, louvers spaced inwardly from the heat exchanging faces of said units to hold stored product away from the units and to control the circulation of air between said faces and the stored product, and said units being operative by circulation of a heat exchange medium therethrough to control the temperature of the atmosphere in the storage zone.

8. A structure for a body of a transportation means having a storage compartment formed therein, said means including a supply header for heat exchange medium, and an exhaust header for said medium, and comprising a wall structure made up at least in part of a plurality of separate heat exchange units, each of said units being removably connected between said headers, each of said units including a ilow passage for the medium, each of said units having an exposed heat exchanging face, each of said units having louver means supported integrally therewith between said face and the storage compartment to hold stored product away from the heat exchanging face and to control the circulation of air between said face and stored product, said units being arranged in side by side relationship and together forming a substantial part of the inner wall for the storage compartment of said body, and saidunits being operative by circulation of a heat exchange medium therethrough to control the temperature of the atmosphere in the storage zone.

9. A structure for a body of a transportation means having a storage compartment formed therein, said means including a supply header for a heat exchange medium and an exhaust header for said medium, and comprising a wall structure having an outer insulated layer and an inner layer made up at least in part of a plurality of separate heat exchange units, each of said units being removably connected between said headers, each of said units including a ow passage for the medium, each of said units having an exposed heat exchanging face, said units being arranged in side by side relationship and together forming a substantial part of the inner wall for the storage compartment of said body, means for shutting oi the supply of said medium, and means for closing the exhaust header after said iiow passages have been emptied whereby said units contribute to the insulating properties of the wall structure, and said units being opera-- tive by circulation of a heat exchange medium therethrough to control the temperature of the atmosphere in the storage zone.

10. A standard structural unit for use in association with the storage compartment of a transportation means having walls to support a heat exchange supply header and an exhaust header for said medium; said unit being adapted to be assembled in said means, between said headers, and along with others of said units to form a substantial part of the inner wall surface surrounding said compartment; comprising a chamber to receive the heat exchange medium; means lto connect said chamber to each of said headers; said chamber being of a size and shape to be removably affixed against at least one of the walls of said means with one face of the chamber exposed to said storage compartment; louver means formed integral with said chamber in front of but spaced from said exposed face; the individual louvers of said means being divided into two sections, the upper of said sections being disposed to direct warm air at the top of the storage cornpartment downwardly against the exposed faceof said chamber, and the lower section of louvers being disposed to direct cold air flowing from said exposed face outwardly against the floor of said storage compartment.

BEVERLY E. WILLIAMS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,773,460 Kelly Aug. 19, 1930 l2,217,702 Kleist Oct. 15, 1940 2,381,796 Williams Aug. 7, 1945

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