US1882640A - Refrigerating and display apparatus and method - Google Patents

Description

Oct. 11, 1932. c. L.. JONES ET AL REFRIGERATING AND DISPLAY APPARATUS AND METHOD Filed April 25. 1930 4 Sheets-Sheet l .5 INVENTOR Charle'. fangs Oct. 1l, 1932. c. 1.-. JONES ET AL 1,882,640

REFRIGERATING AND DISPLAY APPARATUS AND METHD Filed April 26. 1930 4 Sheets-Sheet 2 INVENTOR War/9,5'

ATTORNEY C.' L. JONES ET AL Oct. ll, 1932.

E REFRICERATING AND DISPLAY APPARATUS AND METHOD Filed April 26. 1950 4 Sheets-Sheet 3 u x ca...

ATTORNEY Oct. l1, 1932. c.. l.. JONES ET Al. 1,882,640

GERATING AND DISPLAY APPARATUS AND METHOD Filed April 26. 1930 4 Sheets-Sheet 4 MIME! "l. l l

` MINIMUM WIW H NNNNNN jill Patented Oct. 11', 1932 UNITED STATES PATENT orinar.

CIEZAIRLES L. JONES, 0F PELHAM, NEW YORK, AND'HOWARD MCILVAIN, OF :BELLE-4 VILLE, NEW JERSEY, ASSIGN'R TO DRYICE EQUIPMENT CORPORATION, AOF NEW' YORIL N. Y., A CORPORATION OF DELAWARE REFRIGERATING AND DISPLAY APPARATUS AND MTHOD t Application led April 26,

Our present invention relatesy more part-icularly to refrigerator apparatus y'for storing and dispensing products, particularly food products containing moisture, either frozen or unfrozen, whlch are exposed to con- /tact of the refrigerating atmosphere, and

particularly where the refrigerator is de. signed to serve also as a show case for displaying the refrigerated products. We have discovered that the refrigerant' storage and show case functions each involves certain difficulties and there are many added comlications when the two functions are comined. y. .f

While all the novel features of our present invention cooperate for the successful combination of both of these functions, it WilLbe evident that these novel features, and certain combinations thereof, may be usefully employed in other relations.

Most of the problems involved relate to f preventing deposits of moisture in undesirable places under certain conditions, as for instance, on the glass through which the products are viewed, or on the products themselves; and to preventing the dehydration of the exposed food products, frozen or unfrozen, under other conditions. Both these difficulties increase according as normal temperature in the refrigerated space is low, and particularly where the range is considerably below the freezing point of'water, as is necessary for frozen products. Even for higher temperatures attainable with water ice, very rapid convection currents must be utilized to distribute the refrigerant values because the refrigerant itself is so very near the maximum temperature permissible for proper refrigeration. As Iwill be explained, such rapid currents increase the difficulty.

As one .factor in the solution of these problems, we employ an intensely cold refrigerant source, preferably solid carbon dioxide, becalse with the latter merely varying the amount or nature of its insulation enables us to obtain a temperature range near or above freezing; or any lower temperature range that may be desired in case the apparatus is used for frozen products, or as a freezer` for unfrozen products. While the gas sub- 1930. Serial No. 447,499.

limated from the solid carbon dioxide, is very beneficial for fish and some meats, nevertheless, there are other foods and vegetation to which it may be harmful and in the refrigeration of which it may be desirable to prevent even a very low concentration carbon dioxide gas atmosphere from contacting therewith. Moreover, it is difficult to utilize the -gas as the refrigerant heat-transferring medium without more or less localizing undesirably low temperatures in the lower part of the refrigerated space. Hence we prefer to employ means whereby the carbon dioxide gas may be excluded from the refrigerated spaces, or may bel allowed to enter some or all of them, as may be desired.

Some of the difficulties involved in avoiding deposits of moisture in undesirable places will be evident from the fact that when such a refrigerator is opened for removal or re-l placement of refrigerated products, even through high level doors, some ofthe cold air will be spilled out or expelled by the arm of the operator, and warm air and moisture -from the exterior will enter the refrigerated ture range is low, as in the case of frozen prodl ucts, a relativelyslight cooling of this warm, moist air may cause it to become saturated. Thereafter, further cooling of said air to the normal internal temperature, will be accompanied by releaseor condensation of a corresponding amount of excess moisture. That is to say, after the incoming air has cooled enough to become saturated and While it is being further cooled down to the normal temperature of the refrigerated space, its moisture content will be deposited upon lcontact with any surface colder thanitself, including surfaces of refrigerated Lproducts and inner surfaces of the windows through which the display is viewed, the deposit being either water or frost, according as the condensing surface is above o-r below freezing point. The more rapid the circulation of convection currents in the refrigerated space, the more likely are these moisture deposits to be made in undesirable places.

-VVhile temperature differences causing rapid convection currents may thus cause undesirable moisture deposits whenever the doors of the refrigerator are open during the day time, such currents are also undesirable for other reasons, during nights or holidays, when the refrigerated space remains closed for long periods. Under such conditions, thermo circulation of convection currents tends to become regularized in a single, closed circuit from top to bottom of the entire refrigerated space, the chilled air liowing downward from the coldest spot in the refrigerated space, namely, the refrigerant container. This" container is located at a high level in order to avoid over-refrigeration of the lower parts of the space, and such cold down flow will draw in the warmer, moister air in the top of the` refrigerated space.' Uninterrupted thermo circulation of such convection currents will operate to condense or freeze out all but the minimum moisture content re` quired to saturate the air at the instant when it is coldest, namely, the instant when it is in contact with the refrigerant container.

VThis coldest air flows downward in the relscatter the thermo circulating convection currents in the refrigerated space, thereby minimizing'both the dehydration effects last described and lalso the moisture deposit effects last described and also the moisture deposit effects previously described. 'We accomplish this by arran ing highly conductlng metallic paths wit adequate heat absorbing surfaces extending to relatively remote regions of the refrigerated atmosphere and affording paths of great heat carrying capacity extending-from said regions to the refrigerant container. 'The heat conductor is preferably designed to present approximately uniformly distributed heat absorbing area and to have its' heat flow section increasing from the more remote portions tothe re rigerant container, so that the heat "absorbing areas in the more remote parts have relatively slight temperature differences.

Thus, any atmospheric convection currents tending to .be set up by such heat absorbing areas 'will' be distributed with approximate uniformity and, being ydiffused instead of localized, will be of minimum velocity. Such conductive extensions frornthe refrigerant container, preferably extend horizontally, preferably at a levelI substantially below that of the refrigerant container and preferably below the level of any door openings through which cold air can spill out and warm air enter.` Suchconductive extensions serve not only to directly short circuit, divert and diffuse thermo circulation of the air, but also to greatly raise the temperature of the cold spot, namely,vthe lower portion of the refrigerant container. Thus, the temperature differential tending to cause top-tobottoin, end-to-end unitary thermo circulation is decreased and the part of the refrigerated atmosphere below the spill level of .he door is provided with distributed, less cold heat absorbing surface adapted to maintain a diffused, unobjectionable convection circulation oft-he unspilled cold air that always remains inthe lower part of the refrigerator. g

Another important feature is separating the stored products from the displayed products, by partitioning off the latter in a separate compartment adjacent the show window. Such partition will protect the glass front as well as the displayed goods from direct contact and moisture deposits,

when the service door of the storage compartment is opened, even though the spill level of the door opening be below that of the glass front.

Another feature involves utilizing one of the conductive distributing extensions from the refrigerant container as the partition for separating the two compartments. Such a partitionbeing of great heat conducting` capacity, tends to absorb heat effectively and more or less equally from both compartments; also in case of unequal temperatures as between-the compartments, to absorb more heat from ythe warmer compartment; also ,in case of failing supply of the refrigerant, to transfer`heat directly from the -coldest to the warmest compartment. The latter function may be supplemented by loose joints permitting leakage of atmosphere from the storage tothe display compartment. In this connection,-it is to be noted that in normal operation, when kthe service doorsY are closed,

the display `compartment always tends to be the warmest because the glass window is practically transparent to and admils radiant heat wavesA from the exterior, which 'are trappedwithin said compartment on the principles well understood in connection with greenhouses. As this compartment must be strongly lighted in order to serve its function of display case, veryconsiderable amounts of radiant heat thus enter and are trapped, particularly where show window' lamps and reflectors are employed.

While all of the above improvements tend stead of being a single sheet of glass, comprises at least two, and preferably four, parallel sheets with interspaces between them. In and out breathing of moist air in these interspaces may be prevented by perfect packing, but temperature and barometric changes make it dicult to keep such pack. ing perfectly tight, and to avoid ythisv difficulty we provide for circulation of carbon dioxide gas from the refrigerant container into all of said interspaces, preferably serially, by zig-zag flow from one side edge of the inner interspace to the other side edge of the next interspace. The amount of gas thus flowing need not be much greater than required to maintain a continuous outflow to the air from the outermost interspace and this may be adjusted to suit conditions! either by a valve in the supply pipe to the first interspace, or b varying the size or level of the outlet of' t e last interspace, the latter expedient-operating by reason of the variable,

siphon effect determined by the height of the outlet `from the outermost interspace.

Our invention also includes a special construction of refrigerant container with 'attached extension for conductive uniform absorption and conduction of heat from the refrigerated space Jto the refrigerant. One feature vis that the container itself may b-e located at or above the \level of inflow of air when the refrigerated space is open and the principal heat absorbing 'extension thereof is located below the level at which the cold air can spill out of the refrigerated space. The object of this is to keep this. warmer heat absorbing member submerged in the continuously retained, dryer, colder part of the refrigerant atmosphere, while the refrigerant container is in the highest, most variable, warmest, most moist part.- With this arrangement, it has been found possible to have practically all of the moisture deposit and resulting insulating effect localized on or immediately adjacent the refrigerant container, while the lower level heat-absorbing area is of such uniform, higher temperature i broken away to vertical section on the line 2 2, Fig. 1;

Fig. 3 is a vertical-section on the line 3 3, Fig. 2; K I

Fig. 4 is another vertical section taken on the line 4 4, Fig. 2;

Fig. 5 is a top plan view of a slightly modilied form;

Fig. 6 is a vertical section on the line 6 6, Fig. 5;

Figs. 7 and 8 are vertical transverse sectional "views corresponding to Figs. 3 and 4, respectively, butshowing aI modified form;

Figs. 9 and 10 are similar views on a much larger scale, showing details of structure and gas circulation for the show window;

Figs. 11, l2 and 13 are large detail views of a preferred form of the solid carbon dioxide container and its integral heat conducting extension, Fig. 11 being the plan view, Fig. 12 an end elevation, and Fig. 13 a front elevation with the container shown in vertical section.

In these drawings, the refrigerator case is filled with insulating material, kapok 3 being preferred for the side walls and solid material such as cork 5 for the bottom. In any case, the insulating material in the side walls should be suliiciently porous to permit saturating it with carbon dioxide gas, while the material in the bottom should be firm enough to support the desired loads on the bottom of the inner shell. i

The shape of the refrigerator and the genf eral disposition of its operating parts is somewhat the same in all the figures. As shown in Figs. l to 4, the structure is relatively long and narrow, and has a central transverse partition separating it into two parts and in each part the elements are symmetrically disposed with respect to the plane of said partition. In each half, the front elevation shows a vertically disposed front wall A, a rearwardly inclined display window B through which may be seen a door C affording access to the display space behind the window. The top plan view, Fig. l, shows the same rearwardly slanting display window B, and in addition the high level closure or hatch D, through which the refrigerant container is charged, and theL closure Eat av lower level through which access is had to the storage space F (see Fig. 4).

With this arrangement of parts, it will evident that with a refrigerated atmosphere consisting of air only, an ordinary uninsulated metal container of carbon dioxide, located at a high level, upper corn-er of the space would naturally tend to establish high velocity convection currents flowing downwardly aur from the container, lengthwise ofthe bottom, upwardly at the central partition and back under the upper wall or roof. VMoreover, the

upward circulation would be largely-adp# cent the outer walls which are most exposed to heat from the exterior. With such idea of the normal convection currents under conventional conditions, the novelty and eectiveness of the various features constituting our invention, may be more easily understood and appreciated.

In the upper part of the case, preferably in the remote end of each section, is fitted the refrigerant container 7 which is open atthe top for filling, closure D preventing entrance of outside air. The gas evolved from the solid 'carbon dioxide in the container being preferably kept out of the refrigerated space, is disposed of in various other ways, as'by discharge into the kapok insulation through vent 14, discharge through the joints of the coverD, etc. In Fig. 2, the refrigerant container is shown as surrounded by insulating material on three sides,so that only the bottom and front are exposed tothe air circulation in the refrigerated space. Even these surfaces are not excessively cold because of the massive largo area heat collectinv extensions designed and operating on the principles heretofore explained. In the form shown in Figs. 1, 2 and 3, the extension 8 1s in the form of a widevertical plate integral with the containerV 7 ,extending below theI same, and laterally along the wall, in operative heat absorbing relation to the atmos` phere, to remote points in the refrigerated space. 4 Y

The container and its integral extension i are made of comparatively thick metal of high heat conductivity ysuch as aluminum. The walls of the container taper from a thin upper edge .down to a thick bottom, and the' lateral extension tapers from great thickness at the line of union with the bottom ofthe container, downto relative thinness at the remote end. The effective heat absorbing surface of this member may be varied either b lmaking it of greater or less width or provic ing it with fins, as shown. Preferably, it is bolted to the rear Wall as shown, so that only the front surfaceis effective for absorbingheat from th-e'atmosphere.

The cross section and taper with reference to the heat absorbing area and the temperature to `be maintained in ythe refrigerated space may be 'designed for a reasonable approximation of uniform temperature l, throughout the entire heat absorbing area of the'extension, for the above described purpose of vcorrespondingly distributing and rendering uniform thelocal convection currents which may be set up thereby. Ob-

` v iously, the wider the distribution. andthe greater the uniformity of such currents; the less will be their velocity at any o ne point.

All of these factors' contribute to enfeeble and confuse thermo circulation to a degree approximating stagnation so far as concerns danger of depositing. water or frost on the products during times when the service doors are frequently opened or objectionably dehydrating said products when the doors are closed for long periods. i

Container 9 may have a cock for discharging gas directly into space F.4

W'hile it would be possible tohave duplicate heat absorbing extensions for both walls of the refrigerated space, we prefer to secure to the front wall' 11 of the refrigerated container a heavy metallic heat absorber and con! ductor which also servesthe purpose of a partition 12, closing ofi' a separate compartment in Which products may be specially arranged for display instead of having the display consist of the stored. 4products in the storage 95 space. IVhile this partition member mightvv be cast `integral with the front wall of the container and might be of castiron or other metal, We prefer to make it of sheet or plate aluminum. Although only one sheet is shown, it is easier to bend the partition to the requiredcurvature and yet have it of desired thickness, by employing twoy thicknesses,

`heat collector for the refrigerant container in addition to serving as an equalizer of temperatures between the compartments when either one tends to be warmer than the other. ,110 It may be supplemented by an integral extensiona, from the bottom of 9. The window is of the multiple panegtype, having any number Ofpanes 18, the panes being spaced apart to provide the carbon dioxide gas circulation spaces 19. At -the up Jer side of the window is a pipe 20 connecting the innermost space 19 with. the'refrigerant container. This pipe has a three-way valve at some point in its length to provide for venting gas into the display section 21 or to the spaces 19 or to both of them simultaneously. The gas is led from the refrigerant `ed at the end opposite 22, the gas in itsdownward path and longitudinalflow will become eoV warmer than the freshly evolved gas admitted at 22, the new gas entering the innermost space being heavier than the gas already in there which has had time to warm up, said warm gas will naturally be forced up through the next space 19 and may be vented to .the atmosphere through the vent 24 which is located at the opposite end from the by paths 23. The arrangement of intake and outlet and communications between the spaces so as to be alternating between the ends of the' window, insures a complete circulation of the cold dry carbon dioxide gas between the window panes. When the gas is circulated in this manner we have the coldest gas next the innermost pane which of course is the coldest and as the gas proceeds toward the exterior vent each successive pane with which it comes in contact is warmer than the precedingone, consequently there is no abrupt or sudden fall of temperature but a slow, even fall, whereby when it reaches the outermost pane, the gas 'is so near atmospheric temperature, that it cannot chill the pane enough to cause it to condense moisture on its outer surface. VThis container, according to size of the comparte ment 21. A rack or shelf either permanently attached or removablemay be placed in the compartment 21 to hold the products to be y displayed. -Avsubstantial gas-tight door or closure 25 permits of access to the space 21, without opening the service door E. This construction provides a substantial air-tight display space which is not exposed to inlet of outside atmosphere at any time except when the Same is eitherbeing dressed or undressed for display purposes, consequently there will be very little changeof temperature Within the space atany time. Y

The storage or dispensing space-F is preferably much larger than the display section and being subject to a more or less frequent intake of outside tem erature, due to the opening of the doors, it as been found necessary to provide a much greater heat absorbing area within this space than is required for the section 21. ,This diiiiculty is overcome by adding to the high heat transfer surface 9, the depending and longitudinally extending radiator-or fin section 8.

It can readily be seen that-our invention provides a plurality of refrigerated spaces,

each maintained so that there is `no direct communication with the other, and a container of refrigerant, preferably solid carbon dioxide, in high heat conducting relationship tonear and remote portions of the refrigerated spaces, ybut without using the gas from the solid carbon dioxide as a part of the atmosphere of' the refrigerated space, unless and only to the extent desired; and at the same time minimizing convection gcurrents and objectionable deposits of moisture and dehydration of pro-ducts.

If the caseis of suiiicient size, there can be a unit in each end as clearly shown in Figs. 1, 2 and 5, having partitions 26 to divide the case in sections, thus facilitating defrosting of the case, when the same becomes necessary, by permitting one side of the case to continue in operation while the other side is being defrosted. :The troughs 27 are provided to catch or dratsT olf water when the def'rosting is being done. By reference to Figs. 1, 2 and 4, it will be evident that a work space or table 28 is provided and obscured from-view by the two refrigerant bunkers on the ends and the display section in the front. Access to the storagp space is'had through the openings 29 w ich are closed by the doors or plugs E, of any conventional type.

In Figs. 5`-and 6, a slight modification is shown. In this construction, the work table 28'is supported, `above the top of the casing 28, the latter being inclined andprovided with doors 29p adapted to slide beneath said table. This increases the height ofthe storage chamber and makes. the entrance, 256,

to the display space 216, through the storage chamber 106. This modification has the advantage over the first construction of never permitting direct inflowof outside atmosphere to the display space as is the case of the construction` first described. The entrance 256, with its closure-25e, is conveniently placed with reference to the opening 296 which is clgsed by the door 290 to permit of leasy access to the interior of the display space and when the door 256 is opened, instead of outside atmosphere entering the displayspace as would be the case in Figs. 1, 2, 3 and 4, the dolder, dryer atmosphere from within the storage chamber-16 will enter, thus causing much less disturbaneev of the temperature and) moisture conditions within the display space.

As it is more-,important to su pl y carbon dioxide gas to the window in ront of' the display section an to the insulation, We -find it better to place the vent 24 as low or llC lower than the vent 14, asin Fig. 3. This throws the intake-2O below the vent 14 thereby insuringv a f ull supply of carbon dioxide gas to the, spaces 19, before the gas level rises high enough' to overflow opening I14.

The formshown in Figs. 7 to 13 contains all of the elements foun in the preceding there are other features which are functionally important.

The above changes in size and proportion greatly reduce the volume of the higher, Warmer upper 'part of the atmosphere Within the storage chamber. Moreover, as shown in Fig. 8, one side of the refrigerant container is laterally exposed to this part of the atmosphere. Furthermore, the heat collecting extension 8m, instead of extending laterallyon the same level as the bottom 9m of the container, is brought down to' a much lower level,ras Will be evident from Figs. 12 and 13; also the bottom of the container and its junction with the heat collector is very much more massive.

This combination of changes, as actually tested out in practice, has the advantage that the exposed endY and lower part of the refrigerantcontainer does all of the freezing out of the Water so that in normal operation there is no accumulation of frost or ice on the low level heat collector 8m. Consequently,While frost or ice collecting on the container affords gradually increasing insulation therefor, the heat absorbing surface of 8m remains unmodified and in full operation. Moreover, the height and narrowness of the upper space Where the freezing out takes places makes it more difficult for cool air in the bottom of the storage space to .join in a complete top to bottom thermo circuit, the upiiow into this region as Well as return iiow to the refrigerant container being deadened and diffused by heatabsorption due to the relatively close juxtaposition of the cold heat absorbing surfaces 8a: and 12m which extend along this part of the natural return path of any top-to-bottom, 'end-to-end, thermo circulation. See Fig. 8.

While the dimensions and proportions of parts of the apparatus may be varied Within Wide limits, it may be noted that in a special case a refrigerator proportioned, constructed and successfully operated as last above described, the refrigerant container 7m was of cast aluminum or aluminum alloy and of about l cubic foot capacity, with the side Walls having a thickness of approximately one-half inch at the top, increasing to.one

. inch or more at the bottom, and the horizontalvbottom wall was approximately the same one inch thickness at the base of the outer wall 1141:, increasing to one and three-quartion with the horizontally extending heat collector 8m. The latter is -approximately three feet, four inches long by eight and onehalf inches high, and is tapered in thickness from one inch adjacent the refrigerant container to three-eighths inch at the remote end, the latter representing the `minimum thicknesses, exclusive of the ribs.

'Ihe above dimensions, proportions, tapers, etc., may be varied Widely in order to. more accurately suit the same or dierent conditions of use, particularly different vdimensions of the refrigerated space and different temperature ranges of desired normal operation, but it is understood that all such adaptations should be governed and .determined y by the principles and functionings heretofore explaine It must not be inferred from the .foregoing that the. n'ovelprinciples of our present invention require any great exactitude of proportioningor design of the apparatus in order to get entirely satisfactory practical results as concerns avoiding undesirable moisture deposits. and dehydration of roducts. In thisconnection, it may be Well to note as concerns any apparat-us'embodying these principles, the normal temperature range of refrigeration can be easily controlled, merely by varying the insulation of the solid carbon dioxide Within the container.

For instance, in apparatus as above described, with a supply of solid carbon dioxide entirely uninsulated and resting upon the aluminum bottom, a very uniform, low temperature could be maintained below zero, but merely interposing a sheet of Wrapping paper forl rWith it on an opposite Wall of the refrigerated space.

lOOV

refrigerant container and heat collector structure, such as above described, it is to be remembered that the great heat storage. ca-

pacity of the aluminumV or other vmetal is Y proportional to the mass as Well as -to the specific heat of the metal.y In the present connection, heat storage capacity is the same thing as refrigerant storage capacity, that is 'to say, the greater the mass of the metal, the

more heat units it must absorb in order to raise its temperature one degree, and the more massive are the parts intervening between the warm regions andthe cold regions, the more quickly and effectively can any one region tap the refrigerant reservoir capacity of any other region, either for warming or for cooling. l From the above, it` will be evident that the total mass of the entire system is important,

and that the massiveness toward and at the bottom of the refrigerant container is important. These heat storage and conductivity relations of parts of the system, tend to maintain constant temperature in each part of the system; and changes of tempcarture of the atmosphere in any part of the system tend to equalize, slow down and minimize changes of rate of the evaporation of the solid carbon dioxide.

Hence, while the refrigerant container and heat collector structures such as above described could be made of metal of less heat conductivity than aluminum, as for instance,

cast iron, nevertheless, for equal conductivity and storage capacity, the thicknesses, particularly of the heat conducting extensions, would have to be greatly increased. For instance, if thepartition wall 12m were of cast iron, its thickness might be, say inch to 5A), inch. Even so, its heat transfer rate, particularly .as between the two compartments, would be less than that of the quarter inch aluminum.

Figs. 7 and 8 show the window Bx with lamps 30 and reiectors 31for lighting the display space 21m, tending to warm the upper part of the window and to radiate heat through the glass into said space Ql. The window has four sheets'of glass 18x, affording three interspaces 19a, 19?), 190, and Figs. 9 and 10 show that the first space 19a, and second space 19?), maybe serially connected at the bottom, as at 23m. The third or outer space, 190, is serially connected through-23e, so=that it is supplied only by overiiow from the warmest air in the intermediate space 196. This outer space, 19e, can be tapped at the bottom, as shown at '2400, thereby making it a definite downow leg of the circulation. In such case, the escaping gas will be drawn from the lowest part of the interspace where the coldest part of the gas gravitates, thereby avoiding possibility of a cold spot and possible condensation on the lower part of the outer surface of the outermost pane. However, the gas overflowing into this third outermost space, from the top of the second interspace is likely to be so warm 'that even the coldest of it is net likely to cause such condensation even onthe lower part of the outer surface of the outside glass. Consequently, itis possible to plug the lower outlet 24a and providey a top outlet as indicated at 243/; in which case,

this space becomes a mere pocket; or the outlet may be at any intermediate level, as indicatedatfliz; In the latter connection, it

isto be noted that when the'gas supply and.

outlets are such as to maintain the interspaces at approximately atmospheric pressure, the flow of gas will be controlled by the difference in altitude between the inlet 22m and the oulet 24m, or 242. In such case, the ilowY of gas will be a maximum when the lowermost outlet 24a: is open, and correspondingly less when 24m is plugged and 242 is open. "When 24m and 24e are closed and 24g open, the rate of flow will depend on the difference in temperature of the gases in the iirst` .and second spaces. While voluminous flow can always be forced by pressure of the gas at the inlet 22m, the distributed, optional outlets, at diii'erent levels, are preferable for controlling slow rates of' How through the interspaces to give the gas time to warm up before it reaches the outermost glass.

`While the above described continuous iiow of carbon dioxide gas through the successive interspaces between the panes will have the advantages above described, it will be understood that the insulating quality of the gas even when warm and stagnant is of great valueand, if desired, the outlet may be plugged after the interspaces have been freed from air and moisture and have been filled with the pure dry gas. In such case, the connecti on to the source of gas may be retained so that any in and out breathing due to temperature or. barometer changes will consist ofpure gas. Or, in certain cases where the construction and packing of the glass is perfectly tight so as to withstand expansion or contraction without inbreathing, the inter- Spacesmay be purged of air and moisture, [illed with gas and plugged.

We claim: l. In a refrigerating apparatus the method of preventing moisture deposits, by means of the refrigerant, on refrigerator windows consisting of parallel plates with interspaces. which method includes sublimating solid carbon dioxide and discharging dry gas therefrom into the inner, coldest interspace and conducting the same serially through the successive interspaces, to the exterior atmosphere.

2'. A refrigerator apparatus comprising tition closing oli'V a display space adjacent said Window.

8. A refrigerator apparatus comprising an insulating casing, having a high level service door, in combination with a high level container of solid carbon dioxide having aV massive metal wall and a massive, highf 1y conducting heat collector extending below the level of said container, to horizontally remote regions of the refrigerated atmosphere and affording heat flow paths of great heat carrying capacity, extending from said regions to said refrigerant container, a wall of said casing having a display win-` dow and said refrigerant container having a second highly conducting heat collector formed as a partition between said service door and said window separating a storage space acfessible through said door, from a display space adjacent said Window.`

4. A refrigerator comprising an insulating casing with a window having a plurality of panes affording insulating interspace,

a thick wall of good conducting metal opposite said window and a container of solid carbon dioxide outside of said wall absorbing heat from said wall through an all-metal path to eect refrigeration of said chamber, the gas sublimated from said :solid venting to the exterior' partly through the interspace between said Window panes thereby further heat insulating the interior of the refrigerator;

5. A refrigerated case having walls of porous material between inner and outer surfaces substantially impermeable to carbon dioxide gas, a solid carbon dioxide container in` the upper part ofpsaid case, a storage, chamber below said carbon dioxide'container, a display section in front of said solid carbon dioxide container and said storage chamber, and a communication between said ous path through said spaces between saiding the gas from entering the refrigeratedA spaces.

Signed, at` New York, in the county of New York and State of New York, this 24th day of April, A. D., 1930.

` CHARLES L. JONES.

HOWARD S. MCILVAIN.

Ysolid vcarbon dioxide container and Y said porous material whereby carbon dioxide gas from said container is led to and permeates said porous material.

r6. A refrigerated case enclosing a solid carbon dioxide container, a storage chamber and a. display section, a spaced apart multiple pane window in front of the display section and a conduit to carry carbon dioxide gas from said solid carbon dioxide container and vent the same in a space betwen the said window panes thereby further heat insulating the interior ofthe refrigerator.

7. A refrigerated caseicomprisingaf solid carbon dioxide container, a storage chamber and a display section, a spaced-apart multiple pane window in front of said display section, forming a plurality of spaces between said panes, and a conduit to carrv carbon dioxide gas from said solid carbon dioxide container and vent the same in a space between said window panes, said spaces being interconnected whereby carbon dioxide gas Hows in a. tortuinV

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