US2677245A - Apparatus for utilizing solid refrigerants - Google Patents

Description

May 4, 1954 B. F. EDMoNDsoN 2,677,245

APPARATUS FOR UTILIZING SOLID REFRIGERANTS Filed Sept. 18 1950 4 Sheets-Sheet l llllllllllllllllllllllllllllll ll Il ,rw/

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APPARATUS FOR UTILIZING SOLID REFRIGERANTS Filed Sept. 18, 1950 4 Sheets-Sheet 2 -1NVENToR- BENJAMIN F. EDMoNpsoN avg/Hlth@ May 4, 1954 B. F. EDMoNDsoN 2,677,245

APPARATUS FOR UTILIZING soun REFRxGERANTs Filed Sept. 18, 1950 4 Sheets-Sheet 3 3% M fr! w ff ff M fg M g f6 W ff f/ W if JNVENToR.

FIG.8. BENJAMIN F. EDMoNDsoN May 4 1954 B. F. EDMoNDsoN 2,677,245

APPARATUS FOR UTILIZING soLIn REFRIGERANTS Filed sept. 18, 195o 4 sheets-sheet 4 FIG. IO.

- INVENTOR. BENJAMIN E EoMoNosoN Patented May 4, 1954 PATENT OFFICE APPARATUS FOR UTILIZING SOLID REFRIGERAN TS Benjamin F. Edmondson, Springfield, M'o.

Application September 18, 1950,. Serial No. 185,391

. 8 Claims. 1

This invention relates to apparatus for utilizing `soli-:l refrigerant-.s such, for example, as solid carbon dioxide. The invention is particularly concerned with apparatus which is useful `in portable cooling units of the type employed by campers, as a refrigerator unit adapted for application lin bottled or bulk beverage coolers, for the transportation of perishable goods both in land and marine transportation applications, and for the refrigeration andv maintenance of medical supplies. The invention is also concerned with the provision of apparatus for utilizing solid refrigerants which will make available a-source of refrigeration or cooling where the absence of electricity prevents the use of electrically operated reirigerating and cooling apparatus.

Itis an object of the present invention to pro vide improved apparatus which will eiiiciently utilize a solid refrigerant, such as solid carbon dioxide.

. It is a further Vobject of the present invention to provide improved apparatus which 'will permit close control of the cooling or refrigerating capabilities of the solid carbon dioxide refrigerant.

It is an additional object of the present invention to provide a unit type refrigerating or cooling apparatus which will be useful in many different installations and can be Vadapted tohandle small as well as large cooling loads, through the provision oi heat absorber means having a controllable areaexposed to the heat source.

A 'still further object of the present invention is to be found in the provision of apparatus which will extend or prolong the useful life of solid carbon dioxide refrigerant by regulating the rate of heat transfer, and by more perfectly insulating the refrigerant through support thereof in a manner allowing its vapor to form a nrst heat lbarrier and bythe use oi a vacuum walledcasing having reflective surface coating means applied thereto.

Another object of this invention is to provide apparatus which will be capable of holding solid carbon dioxide refrigerant at -such a low rate of evaporation that it may be stored for long .periods of time with very little loss or shrinkage, all of which will enable the .profitable yhandling of the refrigerant and thereby expand its acceptance and use.

The present invention consists in the provision 'of a casing which is insulated from the surrounding atmosphere, a metallic supporting meansy or receptacle which is` spaced from the internal walls ci the casing and is capable .of very rapidly accepting 'the temperature of the solid refrigerant, an externally located metallic heat absorbing means which is exposed to the heat load, and in the provision of controllable means for variably and mechanically interconnecting the exposed metallic heat absorber and the metallic supporting means in the casing, whereby the heat load may be transmitted into the refrigerant in a regulated manner.

Amore complete understanding of the present invention may be had in the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is a sectional elevational view of a portable type refrigerator embodying means for utilizing a solid refrigerant;

Fig. 2 is a sectional elevational view vas. taken at line 2 2 of Fig. 1, wherein additional details of the apparatus have been shown;

Fig; 3 is. 'a sectional plan view of one form of controllable heat absorbing means as seen at line 3 3 in Fig. 2;

Fig. 4 is a bottom sectional view as seen at line 4 4, Fig. 2;

Fig. 5 is an 'enlarged and fragmentary sectional view of a modified arrangement of means for controlling and regulating the interconnection between the 'heat absorbers and the solid refrigerant thermal conductors;

Fig. 6 is a fragmentary detail as` seen at line 8 6 of Fig. 5? Fig. 7 is a further detailed view taken at line 1 7 in'Fig; 5;

Fig. 8 is a view similar `to Fig. 5. vbut illustrating a further modified 'control means for the purpose indicated;

Fig. 9 is a detailed sectional view as seen at lined-9 in Fig. 8;

Fig. 10 is a fragmentary sectional elevational view similar to Fig.- 1, wherein a rmodified unit assembly is disclosed;

Fig. 11 is ka bottomsection'al view showing further details of the modified unit as seen at line )2 12 of Fig. 10;,

Fig. 12 is a perspective view `oi a. modified form of heat absorbing means whichis especially useful in connection with the modied apparatus disclosed in Figs. 10,11 and 12;

Fig. 13 is a perspective assembly view of the bale means disclosed in connection with Fig. 10.

Fig. 14 is a sectional elevational view of apparatus which embodiescertain features of the apparatus-of Fig. 1 butadapted to act-as a refrigerant storage and transportation means.

Referring to'Figs. f1 'and 2, .a preferred embodiment of :the invention is `seen to *includea portable type container III having an exterior wall II and an interior lining I2 spaced from the exterior wall so as to permit the incorporation of a suitable layer of insulation I3 for insulating the interior space of the container I from atmospheric conditions outside thereof. The container is of the top open type and is therefore provided with a suitable hinged cover or lid I4 which is also constructed to embody an insulated double wall. The lid I4 is suitably connected to the container at hinge means i 5 and is provided with a suitable latch I6. The casing I0 is further provided with a separate lid or door structure II which utilizes the hinge means I5 and is arranged in the top of the container I0 to provide convenient access tothe interior of the container, and more particularly to the interior of a unit type refrigerator or cooler IB hereinafter to be described.

Still referring to Figs. 1 and 2, the unit cooler I8 is seen to include a suitable sheet metal housing attached to the top and adjacent vertical side walls so as to completely enclose a portion of the container interior located immediately adjacent and below the access opening closed by the cover II. This housing 20 is adapted to enclose a vacuum jacketed casing 2 I the main body portion of which is formed by an internal shell 22 and an external shell 23 suitably formed on their adjacent faces with means to maintain the shells in spaced relation whereby an evacuated space 24 is provided. A suitable cover structure 25 is also provided with an evacuated space 26, and is constructed in much the same manner as the casing 2I. Holding elements 21 are provided for securing the cover 25 on the upper margins of the casing 2 I, in the manner shown. The casing 2l is suitably supported withinthe housing I8 by, means kof vertically directed bracket elements suitably secured to the inner lining or wall I2 of the container by the bracket support means 3I. The casing 2I is thereby held in spaced relation from the housing wall 2i! to permit installation of suitable insulation 32, either in a loose form or in the well known insulation bat form. An additional body of insulation 33 is removably disposed over the casing lid 25. This insulation 33 is adapted to be removed when access to the casing 2| is necessary.

An important feature of the present apparatus resides in the provision of means for supporting a suitable block of solid carbon dioxide refrigerant within the casing 2I so as not to have any part of the refrigerant in direct contact with the surface of the casing shell 22 or lid 25. In the present construction, the casing 2| and its lid 25 are preferably formed of non-heat conductive material, and an excellent material for this purpose may be found in certain of the plastics now commercially available. A plastic material having the above characteristic is preferred for the casing 2I because of its low initial cost and the ease with which it may be formed or, molded into the shape of the casing herein disclosed.

It is known that solid carbon dioxide refrigerant undergoes an increase in its rate of evaporation when placed in direct contact with an insulated body or insulation material. Therefore, it is most desirable, in order to prolong the life of the carbon dioxide refrigerant, to maintain the body thereof substantially free of contact with any surface that is incapable of readily accepting the temperature of the solid carbon dioxide. The use of such a supporting surface for the carbon dioxide refrigerant serves to maintain the carbon dioxide in a more stable condition of low evaporation. Some further increase in the life of the refrigerant is achieved by permitting the body of refrigerant to be enveloped by its own low temperature vapor. Accordingly, in the present apparatus the block of solid carbon dioxide refrigerant 35 is suitably received in a metallic supporting member or receptacle 36 which in turn is spaced from the walls of the casing shell 22. The support 36 is constructed of a high thermal conductivity material having a very thin section wall so that it is capable of very rapidly accepting the temperature of the block of solid refrigerant 35.

The metallic supporting surface or receptacle 35 is supported by one or more thermal conductor means or metallic conductor elements 3i suitably connected with the under surface of the support means 36. The conductors extend through apertures 38 formed in the casing 2I whereby an outer end portion 39 of these conductors projects through the housing Wall 20 for association with means now to be described. In the present embodiment, I have provided three metallic conductor elements extending from the refrigerant support 36 outwardly of housing I8, and I have indicated the end portions at 35, 39A and 35B. It is obvious that the number of such conductors may be altered from that shown and that a different arrangement thereof may be made.

Associated with the housing I8 in the zone adjacent the metallic conductors 31, I have provided a second housing structure 40 and this housing is adapted to enclose control means for regulating the transmission of heat absorbed from the interior of the conta-incr I 0 to the body of the solid refrigerant 35. The housing 40 comprises a sheet metal, pan type structure 4I suitably flange connected (Figs. 2 and 5) to the bottom surface of wall 2U forming housing I 8. This housing is formed to provide inlet openings 42 in the opposite curved end walls, as shown in Figs. 2 and 3. Outlet openings 43 are provided in the bottom horizontal wall of the pan 4I, and these openings are arranged in spaced fan-shaped groups on each side of the location of a pivot element 44.

Control over the inlets 42 and outlets 43 in the means 4I is had through shutter 45 pivoted at element 44 and. angularly moved by a shutter control lever 4B operativelymounted on the pivot 44. The shutter 45 is provided with upturned opposed shutter elements 41 (Figs. 2 and 3) having shutter ports 47A for controlling the opening and closing of opposed inlet openings 42 in the housing 40. In addition, the shutter member 4 5 between the upturned ends is provided with a series of control openings 48 arranged in groups for opening and closing the similar groups of ports 43 in the bottom wall of pan 4I. With this control arrangement, the inlet openings 42 and the outlet openings 43 of housing 40 are simultaneously regulated by angular movement of the shutter 45 to permit a desired volume of air to pass through the inlets from the container I 0 for cooling by heat absorbers before returning to the container through the outlets. Obviously suitablemanipulation of the shutter 45 can result in closure of the respective ports and almost complete separation of housing 40 with respect to the interior of the container ill.

Housing 40 encloses metallic heat absorbing means in the form of solid bars or rods which are hereinafter referred toas extended surface those described in Fig. 2, 'except' for length. Acicordingly, no further detailed description will be 1 given of this shutter control means in connection with Fig. 5. It is understood that in certain installations the shutter 45 may not be required.

Referring to Figs. 8 and 9, I have shown a further modified control means operatively mounted in housing 40 which encloses the controllable shutter 45 previously described. The

modified control means referred to here includes a longitudinally movable or shiftable rod 80 which is suitably supported in bearings 3| and 82 in the opposite end walls of the housing 4t.

One end of rod 80 is pivotally interconnected at pin 83 with a control lever 84, the control lever B4 extending in a direction generally transverse to the length of rod 8G and having one end pivotally mounted in a bracket 85, Fig. 9, and its opposite end directed outwardly of housing 48 for control access. Rod -llcarries elements 8E,

l 81 and 08, having a progressively increased axial length in the order named. These elements 8E, 8l and 88 are adapted to mechanically interconnect the coil bosses 50A. 55 and 55 with the re.

vention is disclosed in connection with Figs. l0 to 13 inclusive, wherein I have illustrated schematically container and the refrigerator or cooling unit I8. I have further indicated in schematic outline the location of -housing 40 and the control lever 46 which is adapted to shift or pivotally displace the shutter 45. In this apparatus, however, shutter 45 is adapted to control only a series of bottom air outlet ports indicated at 43'.

The present modified constructionV which my apparatus may have includes hollow or tubular heat absorbing elements or coils of the type shown at 90 in Fig. l2. These heat absorbing coils areprovided with an inlet opening at 9| for air or other medium to be cooled and a discharge at 92, the air or medium following the path indcated by the dotted arrows in this view. I have provided a plurality of coils 90 Fig. 1l, each of these coils being similar to that disclosed in connection with Fig. 12. Each coil 90 is provided with a thermally conductive element 93 which is adapted to be placed in opposite spaced alignment with the end portions 39, 39A. and 30B of jthe conductor elements 3'1. The space or gap formed between the coil elements 93 and each of the conductors associated with the solid refrigerant is controllably and mechanically interconnected by means of any one of the forms of control devices shown and described in connection with Figs. 2, 5, and 8. Accordingly, no further reference will be made to the control means other than to note that it may have the characteristics of the control means previously described.

In connection with the use of tubular coils 90 in container I0, I prefer to direct the air inlet openings 8| thereof in different directions and to provide each opening 9| with a hood or air collecting scoop. With reference to Figs. 11 and 13, the scoop means 94 is associated with an intermediate coil 90 and is further hingedly mounted to the wall20 of housing I8 at the hinges 95 so that it may be lifted out of the Way when entering the container. This scoop 94 is further provided with baiiie elements 95 which converge toward a port closely adjacent the location of coil opening 9|, thereby eifectively directing the upwardly moving currents of air toward and into the opening 9| for coil 90. In a similar manner each of the laterally located coils 90 is provided with an air scoop 91 projecting laterally outwardly from the lower portion of housing |8 so as to lie closely adjacent the vertical walls of the container and direct the upward currents of air toward and into the respective openings 9| of the associated coils 90. Each member 91 is provided with baille elements 98 convergently directed with respect to the coil opening 9| associated therewith.

In connectionwith the preferred construction which my apparatus may have I have shown in Figs. 1' and 2 means for restricting the pressure v Within the casing 2| so that the body of solid valve element |02.

refrigerant will not be conned therein at pressures higher than would normally be generated upon slow evaporation. For this purpose I provide the casing 2| with an outwardly projecting nipple |00 open at the inside of the casing and having an enlargement or valve chamber |0| at its outer end for the reception of aball type The enlargement |0| which forms the valve chamber is suitably connected with the inlet nipple |04 of a tube |05 which is horizontally directed and completely encircles the 1 casing 2|, as is indicated by comparison of Figs.

1 and 2. The tube v| 05 is provided with a plurality of ports |06 for permitting the escape of the carbon dioxide vapor as the same is expelled from the casing by way of the valve element |02. In this` connection it is noted that valve element |02 is selected as to its weight so that the proper regulation of vapor pressure within the casing 2| can be maintained. In no case, however, is the ball valve |02 intended to act to maintain the body of solid refrigerant at more than one atmosphere, or equivalent minimum pressure condition, the object being to safeguard the casing 2| against excessive pressure and to exclude foreign matter and air leaks while allowing vapor release.

Fig. 14 discloses apparatus which is'useful for solid refrigerant' storage or transportation purelimination of the exposed heat absorbers.

poses, its general construction followingthat Afor the refrigerating apparatus of Fig. 1 with' the The storage apparatus comprises a housing H8 having a removable lid or cover IIS fitted to the |20. A casing |2| is disposed to form a vacuum space |24 which is maintained by the provision of suitable ribs and similar wall spacers, not particularly shown because they vare well understood. The casing |2| is provided with a removable cover |25, also having the vacuum space |26. Cover |25 is held in closed position by elements |21.

This casing |2| may be supported on a plurality of studs or brackets |28 disposed along the length and width of the bottom of housing ||8 so that the casing is well separated from the housing'. A suitable quantity of light weight insulation is located in the space between casing |2| and housing 8, and the cover ||9 likewise carries space |.24v are covered or lined with any of the high reflective surfacing materials, such as bright aluminum foil, .aluminum or other paint and the reiiective. surfacing materials which can be ap,- pliedv by spraying. Thisreective. surface; cover,- ing is indicated at |32 on the opposing surfaces. of the vacuum space of both the casing |21 and its cover |25. This same reflective covering material is applied tothe apparatus of Fig. 1 in the same location and areas, and has been so indicated at |32 therein.

The solid carbon dioxide .refrigerant is. placed' in the casing |2| and issupported on thin walled' metallic means |34 which is capable .of very rapidly accepting the low temperatureV of the .solid carbon dioxide so that the least possible. loss .of the same may result. The use of such an excel'- lent thermal' conductor in a thin walled. form. reduces the time of and extent to which thesolid carbon dioxide forms a liquid lm on the contacting surfaces. Reduction of the ,time ofexist.- ence of this liquid iil'm will' decrease loss ofl the solid carbon dioxide. The support means |34 is held from contact with the inner casing wall |22 by means of a plurality of bottom and side spacer elements |35 and |36 respectively. The bottom elements |35 are suitably formed or molded with the wall |22 to provide several screw posts for the screws |31 which are used to hold the support |34 in the casing |2|, but permit its removal for cleaning.

The spacing of support means |34 from the wall |22 of casing I2| creates the room for an envelope of carbon dioxide vapor about the solid block thereof and further aides in maintaining the block in a low temperature insulating blanket. This same vapor enveloping the insulation blanket is created in the apparatus of Fig. 1. The blanketing Vapor which is slowly given on by the solid block is vented at low pressure, in the range of one atmosphere, to the exterior of casing |2| at vent valve nipple |38 which is similar to the vent valve nipple of Fig. 1. The vapor issuing to the housing ||8 may be vented to atmosphere by a ball type vent plug, as shown at |39 on cover H9 in Fig. 14.

The support means |34 of Fig. 14 and the support means 36 of Fig. 1 may have a solid wall, that is a Wall which is not perforated, or they may be perforated wall structures. It is preferred that perforations be formed so that the vapor can quickly surround the same and to reduce the mass of the support which has to react rapidly to accept the low temperature involved.

The storage apparatus of Fig. 14 may have any suitable or convenient dimensions to adapt it for the uses to which it may be put. It is contemplated the sizes may vary from the small local merchant vending size to the greatly increased, large quantity transportation and storage sizes.

It should now be obvious, from the foregoing description of the preferred structural arrangements which my invention may have, that there has been provided a simple apparatus for utilizing solid refrigerants, as carbon dioxide, wherein the same may be stored or the cooling ability of 10 the solid retrigerantcan .be controlled' and regulated` closely in accordance with an applied heat load. It should be understoodthat my present invention includes within its scope the provision of solid typeheat absorbingelements such as that of Fig. 3 or the hollow or tubular type of heat absorbing elements disclosed in. connection with'` Fig. 13,. It is especially useful to employ hollow coil elements in connection with the cooling or refrigerating of certain` liquids andv Abeverages commercially .dispensed from bulk containers or the like. Numerous other applications will occur to those skilled in the. art and. I deem it within. thepscopev of. my :invention toI have included all such .modieat-ions and rearrangements of parts that. fall within the spirit of the claims herein: after appearing.

What I cla-im is:

l. Apparatus for utilizing solid' refrigerant comprising, a .casing` insu-grated. fromv external temperature conditions, a thermally conductive sup.- port positioned in said casing for` receiving, the refrigerant. and for maintaining it spacedfrom said casing, thermally conductive means disposed outside said casing, said. conductivemeans having a large area for exposure to external tem-f pera-ture conditions, and means for interconnect ingv4 said thermally .conductive support .and eX- posed conductive means to provide a path for. the. transmission of solid refrigerant cooling. eiectto the exterior of said casing,'sai'd conductive means including portions movable into and out of contact with said thermally conductive support to vary the cooling effect.

2. Portable apparatus for utilizing solid refrigerant comprising, a container having a top opening, an insulation housing near the top of said container, a refrigerant casing in said housing, metallic refrigerant support means within and spaced from the walls of said casing, metallic conductor means extending between said metallic support and the exterior of said housing, thermally conductive metallic members positioned at the exterior of said housing exposed to the temperature conditions in the container, and means thermally interconnecting said exposed members and conductor means to establish a path for transmission of refrigerant cooling eiects into the container, said last means being movable to a position out of contact with said metallic conductor means to break the path for transmission of the cooling effect.

3. Portable apparatus for utilizing solid carbon dioxide refrigerant comprising, a portable container, a casing disposed in said container for access through the top thereof and being insulated from the interior temperature conditions of said container, support means in said casing providing a thermally conductive surface for supporting the solid carbon dioxide refrigerant free of contact with said casing, said support means including thermal conductors extending to the outside of said casing, thermally conductive means exposed in said container, and means movably arranged to occupy a position for mechanically interconnecting said conductors and said exposed conductive means to transmit the cooling effect of the solid carbon dioxide refrigerant to the interior of said container and to occupy a position interrupting the mechanical interconnection of said conductor and ,exposed conductive means.

4. Apparatus for utilizing solid carbon dioxide refrigerant including, a container to be refrigerated, a thermally insulated casing in said contaner, metallic heat absorbing means atv the exterior of said insulated casing exposed in said container, a thin walled metallic support in said casing to hold the solid carbon dioxide refrigerant out of contact with the casing Walls and reach a temperature substantially that of the refrigerant, metallic conductor means extending from contact with said support to the casing exterior adjacent said heat absorbing means, and metallic means movable to a position .thermally connecting said metallic conductor and heat absorbing means.

5. Apparatus for utilizing solid carbon dioxide refrigerant as defined in claim 4, and wherein said metallic movable means includes spaced surfaces for progressively varying the thermal connection thus established.

6. Apparatus as defined in claim 4, and wherein said metallic heat absorbing means is of a hollow tubular form presenting an interior surface also exposed to the medium in said container to be refrigerated.

7. Apparatus as defined in claim 6, and Wherein baiile means is provided for said tubular means to direct the medium to be refrigerated into theV coils.

8. In apparatus for utilizing solid lcarbon dioxide refrigerant the combination including, means to support a quantity of the refrigerant, a casing separated from but insulatingly enclosing said support means, a housing surrounding said casing, thermal conductor means extending from mal conductor means and adapted to selectively y connect and disconnect the latter means, and

shutter means operable to open and close said ports for the second housing for regulating the passage of surrounding currents through said second housing from the space outside the latter housing.

References cited in the nie of this patent UNITED STATES PATENTS Number Name Date 1,796,907 Josephson Mar. 17, 1931 1,864,040 Campbell June 21, 1932 1,870,684 Killeffer Aug. 9, 1932 1,887,687 Killeffer Nov. 15, 1932 :1,901,000 Robe Mar. 14, 1933 2,065,987 Rice Dec. 27, 1936 2,067,325 Jones Jan. 12, 1937 2,190,796 Michalske Feb. 20, 1940 2,305,740 Shively Dec. 22, 1942 2,318,222 Heisler May 4, 1943 2,508,385 Hall May 23, 1950

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