US3163024A

US3163024A - Refrigerated cabinet structure

Info

Publication number: US3163024A
Application number: US247181A
Authority: US
Inventors: Beckwith Sterling; Vogel Robert
Original assignee: Dual Jet Refrigeration Co
Current assignee: Dual Jet Refrigeration Co
Priority date: 1962-12-26
Filing date: 1962-12-26
Publication date: 1964-12-29
Anticipated expiration: 1981-12-29
Also published as: DE1451075A1; GB1038500A

Description

De@ 29, 1964 s. BEcKwlTH ETAT.

REFRIGERATED CABINET STRUCTURE 2 Sheets-Sheet 1 Filed DeG. 26, 1962 FIG.

DeC- 29, 1964 s. BECKWITH ETAL 3,163,024

REFRIGERATED CABINET STRUCTURE Filed Dec. 26, 1962 2 Sheets-Sheet 2 JUN" "1 4 a f a FIG-2- INVENTORS F-I G' 4 Serling eckwih B Puber- V0 eZ @m0, WM,

ATTO EN EYS United States Patent Oice Patented Dec. 29, i964 3,l6?=,924 REFRIGEBA'EEB CABINET SERUC'EURE ter-ting Beckwith, Lahe Forest, and Robert Vogel, Deereld, lll., assignors to Daal let Refrigeration Company, Chicago, lll., a corporation of illinois Filed Dee. 26, 19152, Ser. No. 247,1t3l 16 Claims. (Cl. 62-256) This invention relates to a refrigerated cabinet structure which is characterized by a unique arrangement for maintaining highly eilicient refrigeration therein. The invention is particularly directed to devices which are capable of maintaining a refrigerated state within an enclosure while still providing an opening for access to the contents.

In an application of Hagen et al., Serial No. 54,077, tiled September 6, 1960, and in the issued Simons Patent No. 2,862,369, there are described refrigerated display cabinets which are provided with access openings exposed to the atmosphere while still being .capable of maintaining the contents in a refrigerated state. Loss of refrigeration from the enclosed space through the access opening is reduced in a highly efective manner in these constructions bythe use of a gaseous, preferably air, curtain which is continuously advanced across the open side from one edge of the opening to the opposite edge. The air curtain in these constructions is adapted to be formed of adjacent panels of air, with the innermost panel compris ing a refrigerated .cold air panel, and with one or more outer panels having temperatures approaching the ambient temperature. It has been found that it is desirable to recirculate the inner cold air panel and to provide means for circulating the adjacent guard panels, to conserve the refrigeration and to maintain the enclosed space in a satisfactory refrigerated state.

in these constructions there are described assemblies which include nozzles extending across the bottom edge of the access opening to direct the air panels upwardly across the opening towards inlets which extend across the top side of the access opening. As an alternative, the nozzles are located across the upper edge for projecting the air panels downwardly toward inlets arranged across the bottom edge. It is also contemplated that the air nozzles be located across one of the lateral edges of the opening for directing the corresponding air panels across the opening toward inlets in the opposite edge. Because of the more desirable effect of gravity on the higher density cold air, it has been found preferable to provide the air curtain with a downward movement from nozzles across the top to inlets across the bottom. The following description will refer to this preferred construction, although it will be understood that the concepts to be described are also applicable to other directions of ow.

In the use of cabinets of the type described, it is, of course, desirable to provide maximum efliciency insofar as the amount of power consumed is concerned. In refrigeration `systems of this type, the consumption of power is primarily due to the refrigeration of the moving air streams which pass over the access opening for the cabinet. To a somewhat lesser degree, power is consumed during defrosting cycles and due to the driving of fans for circulation of the streams. As far as the refrigeration of the streams is concerned, a major factor contributing to the amount of power consumption is the loss of refrigeration (or intake of heat) through the access opening.

It is an object of this invention to provide a refrigerated cabinet structure which includes novel means adapted to increase the efficiency of operation while maintaining a desired level of refrigeration within the structure.

It is an additional object of this invention to provide a refrigerated cabinet structure which includes highly effective means for decreasing loss of refrigeration and for preventing intake of heat through the access opening of the cabinet.

It is a more particular object of this invention to provide a refrigerated cabinet structure and an improved method of operation which is characterized by a system which provides a unique arrangement of air streams across the access opening whereby the effectiveness of the cabinet operation can be greatly improved.

These and other objects of this invention will appear hereinafter and for purposes of illustration but not of limitation, specific embodiments of this invention are shown in the accompanying drawings in which:

FGURE 1 is a schematic elevation in section of a refrigerated cabinet structure characterized by the features of this invention;

FIGURE 2 is a sectional view taken along the line 2-2 of FIGURE 1 and of the portions of the apparatus between the walls 36;

FIGURE 3 is a cross-sectional view taken about the line 3-3 of FIGURE 2; and

FGURE 4 is a cross-sectional view taken about the line 4 4- of FIGURE 2.

As indicated, the improvements of this invention are directed to refrigerated enclosures of the type which detine an access opening in one wall, which is provided for communication with the otherwise enclosed space. The enclosures are provided with a plurality of nozzles arranged in side-by-side relationship across one edge of an access opening, and corresponding inlets are located across an opposite edge of the access opening. The inner nozzles and inlets are provided for the passage of refrigrated streams across the access opening, while the outer nozzles and inlets circulate progressively warmer air panels. The inner refrigerated streams are circulated through passages having refrigeration coils or the like situated therein, and one or more of the outer streams may also be refrigerated.

In accordance with this invention, a method and means are provided for controlling the streams of air which which provide moving panels passing across the access opening of the refrigerated cabinet. The improvements of this invention are specifically directed to the provision of channel means which communicate with the nozzles and inlets of the cabinet. The channels are defined by sheet-like means which extend transversely across the cabinet. The channels extend from the nozzles and inlets and are joined with conduits which are arranged in a row extending across the cabinet. Thus, a given nozzle will have a channel communicating therewith and this channel will be joined with one conduit. This conduit extends to a channel for an inlet to complete a circuit for air streams passing between the particular inlet and nozzle. Circulating means are provided in each conduit whereby the streams of air in each of the circuits defined between channels and conduits can be circulated for movement in a form of panels across the access opening of the cabinet.

In order to effect the desired channel and conduit arrangement, an opening is provided in each of the sheets which define the channels. The conduits which comprise pipe-like members are each joined with the sheets at a given opening so that an air stream for a given channel will pass into only one conduit. Spacer means are provided for holding the sheets in spaced-apart relationship and means are provided for sealing the channels with respect to each other. In a preferred form of this invention, the spacer means comprise annular rings situated around the opening for a sheet and these spacer means also serve as the sealing means.

In order to provide a conduit communicating with each 3,1 sacas of the channels, it is necessary to place the openings for the channels in diff rent positions so that the conduits can be confined in a row transversely across the cabinet. To provide uniform panels of air across the access opening, it is necessary to employ means for distributing the air coming from conduits across the widths of the respective channels. These means preferably' taire the form of buffers which extend into the channels and which define a single, long, narrow slit across each of the channels. The streams of air passing into the channels engage such buffers and tend to be dispersed laterally across the channel whereby a uniform liow will pass through the slits to ultimately form uniform panels moving across the access opening.

The circulating means are operated whereby the streams of air in the respective passages and channels are moved in the form of substantially laminar panels across access opening for the cabinet, Thus, the streams are moved in a manner such that there will be a minimum o entrainment between adjacent streams and no significant turbulence will be set up at the interface donned by the streams.

Circulating means such as motor driven fans are preierably provided for the innermost refrigerated stream and for each of the streams moving in the conduits above described. Furthermore, the preferred structure provides vfor placement of the conduits in a location adjacent the innermost passage in the cabinet. With this arrangement, an innermost refrigerated stream, adapted to maintain the low temperature in the cabinet, moves adiacent the plurality of streams which are confined by the channels and conduits.r It has been found that the panels issuing from the various channels become successively warmer in a direction toward the ambient air and this step-wise rise in temperature provides distinct advantages insofar as the efiiciency of the structure is concerned.

The construction of this invention also readily lends itself to the concepts disclosed in co-pending application Serial No. 247,245, tiled December 26, 1962, and entitled Refrigerated Cabinet With Circulating Air Panels. In this application one concept disclosed provides for an outer stream of air which is not powered by independent means. However, this stream is adapted to circulate through contact with the adjacent moving stream and therefore a barrier to the intiow of warm air and a means for avoiding spilling or extremely cold air out of the cabinet is provided.

This co-pending application also describes a system wherein the streams of air in the cabinet passages are circulated at different speeds. Specifically, the innermost refrigerated stream is moved at the highest speed and the streams located toward the outside of the cabinet are moved progressively slower. This gradual decrease in velocity is highly effective in preserving the low temperature character of the innermost stream which is responsible for preserving the temperature within the cabinet. By providing progressively slower portions in the streams adjacent the refrigerated stream, it is possible to virtually eliminate turbulence with respect to any outer streams or with respect to the ambient air. As explained in this co-pending application, elimination of turbulence constitutes a material factor in preserving refrigeration and in providing operating eliiciency.

In the case of the structure ot this invention, the speeds of the several streams in the respective conduits and channels can be regulated to provide progressively slower movement toward the outside of the cabinet. As eX- plained in the last mentioned co-pending application, the speed differential must be such that slipping between adjacent panels moving across the access opening will occur. in other words, the system will tolerate certain speed differentials without significantly disturbing the laminar character of the air panels. Due to the fact that several panels are provided when the channel and conduit arrangement of this invention is employed, the use of differential speeds in these panels provides a highly satisfactory operation.

The accompanying drawins illustrate in Fl l a cabinet structure lll characterized by one form of tie invention. rnc cabinet includes a top wall l2, a bottom wall li, a back wall iti, and a front wall i3. File structure defined by these walls is located on a support 2d. The front wall l defines an opening 22 which provides access to an enclosed refrigerated space 2st. rl'he inner wall Z5 defines the extent of the refrigerated space. A partition 22; denes a passage 29 with the inner wall 26 and a refrigeration means Bil and a motor driven ian 32 are located in this passage whereby a refrigerated stream of a can be circulated therein.

Behind the partition 28 and in front of the partition 3d, there are provided a plurality of conduits 36. These conduits may comprise pipe-like members as shown in FIG- LRE l or the conduits may be defined by means ot members 38 disposed across the space between the partitions 28 and lid. In case, each conduit communicates with openings formed in the sheets 42 and d which define the channels above described. In the structure shown in FIG- URE l, the conduit 3d terminates in an opening ill forme in a sheet 52. This sheet deiines one channel lill along with the sheet d: located immediately' thereabovc. ln considering FGURES 2 and ll, it will be obvious that a plurality of other channels are also detined by means of the spaced-apart sheets. Thus, the location of the openings lll in step-wise )fashion with respect to adjacent sheets l2 provides communication with the respective conduits 36. FlGURE l illustrates one opening il in solid lines with the opening dll in the sheet immediately therebclow being illustrated with bro-hen lines. Succeeding openings lll are located transversely across the structure although these are not illustrated in FIGURE 4 for purposes ot simplicity.

The several openings and channels are best shown in FlGURE E which is a sectional view looking from the back of the cabinet. Although FIGURE 2 illustrates a somewhat modified version of the conduits 36. the relationship between the conduits and the sheets which form the channels is essentially the same as in the structure shown in FlGURE l.

The conduits 3o extend along the bottom oi the cabinet as shown in FIGURE l, and they there tern nate in openings flf which are defmed in the sheets lill. These sheets delirio a plurality' of channels 5d, and it will be appreciated that the several conduits 3o each communicate with one channel in the same manner as described above.

Each of the channels 553 extend upwardly from the bottom of the cabinet and terminate in inlets 52. These inlets are preferably covered with screens 5d which serve to prevent ingress of insects or other foreign material. lt will be noted that the inlets 55 for the inner and outer cabinet passages are. also provided with such screens.

At the .top of the cabinet opposite the inlets S2, there are provided a corresponding number of outlets 5d, each comriunicating with one of the channels 44. The structure shown also includes an outer passage SS defined between the outer wall of the cabinet and the outermost sheets 42 and 5G. This outer passage may be i cluded for circulation ot ya guardpanel disposed outwardly of the subdivided panel moving in the conduits 3o and the associate channels. A description of the function of this outer circulating panel is provided in the aforementioned co-pending application entitled Refrigerated Cabinet With Circulating Air Panels.

ln `the outlet for the passage 59 as well as in the outlet for the innermost passage 29, there are lprovided honeycomb membcrs dll. As described in co-pending application Serial No. 91.,.875, entitled Refrigerated Display Case and Elements Thcreo, these honeycomb sections provide highly suitable outlet nozzles for a refrigerated cabinet construction. The sections comprise a plurality of longitudinally disposed, parallel passages which subdivide ,the

streams passing therethrough into a corresponding number of portions. rl`he most satisfactory honeycomb sections have a depth greater than 1/2 inch and preferably greater .than one or two inches whereby the streams of air issuing from the honeycomb can be guided in laminar ow across the access opening the front wall of the cabinet.

It is contemplated that the outlet openings 56 for the channels 44 may also be provided with honeycomb or with other nozzle structures of the type described in said application Serial No. 91,875. Such honeycomb sections tend to improve the laminar characteristics of flow in the streams passing therethrough and such laminar characteristics are, of course, desirable in the streams issuing from the outlets 56.

In order to maintain uniformity in the rate of movement and temperature of the streams issuing from the openings 56, it is desirable to provide means for establishing uniformity in these streams while they are within .the channels 4d. The means for establishing uniformity preferably take the form of barrier members 62 which are shown in FIGURES l and 4. These barrier members extend completely across the channels and also extend downwardly whereby the Iair passing through the channels passes through small openings or slits 64 deiined between the barriers and the sheets 42.

When a stream of air moves out of a `conduit 36 and into a channel ed, the barrier 62 acts as butter means for a major portion of the air stream. Although a large portion of the air stream would tend to pass through the channel 44 to the outlet therefor along a direct path from the opening itl from which it issues, the barrier 62 will disrupt the passage of this large portion of the stream and distribute it laterally across the channel. Even though the openings et) are each in a different position with respect to a corresponding sheet 42, the distributing eiect of the barrier 62 will provide uniformity in the streams issuing from the openings 5d.

In a structure of the type described, there is a tendency for vibrations to be set up as a result of the operation of the circulating fans and other mechanisms. In order to avoid undue noise and wear as a result of these vibrations, it is preferable to provide flexible connections between the conduits 36 and the

sheets

42 and 48. The flexible conneoting means may take the form shown at lthe top of FIGURE l wherein a bellows member 65 connects

tubular sleeves

66 and 68. The sleeve 66 is secured to a sheet 42 while the sleeve 63 is secured to the conduit 36. With a resilient connection provided between the conduits and the .sheets in this maner, vibrations will not be transmitted between these members. Annular blocks 70 which may be formed of wood or other relatively solid material may be provided as spacers for the sheets 42 where a dexible connection of this type is employed.

In the lower section of the cabinet shown in FIGURE 1 and also in FGURE 2, there are illustrated conduits 36 which are directly connected to the sheet members. In this case, the spacers comprise resilient, annular rings '72 which are adapted to absorb vibrations which would otherwise be transmitted between the sheets and the conduit. The rings 72 may be formed of any suitable material which is adapted to retain its resilient character over a relatively long periods and under the prevailing `temperature conditions.

The rings 72 in the embodiment shown also act as sealing means whereby air from a given conduit will pass into only one of the channels. In the construction shown at the top of FIGURE l, the tubular sleeves and the bellows member provide for ysealing the conduits and channels into separate passages.

in the operation of a cabinet designed in accordance with this invention, there is a gradual decrease in temperature realized toward the outside of the cabinet. Since the streams in the subdivided panel are relatively small and since a plurality of these streams areprovided, the differential in temperature between them is not extreme and, therefore, the tendency for movement of heat into the cabinet is reduced. This advantageous result is, of course, accomplished due to the fact that laminar tlow characteristics exist substantially throughout the subdivided streams. Where ditlerent speeds are employed in these streams, the gradually decreasing temperature cooperates with fthe gradually decreasing speeds to further improve the eiiciency of operation.

It will be appreciated that the structure described is subject to many modications which still employ the inventive concepts disclosed. For example, it is contemplated that the cabinet include only two panels, one of which is subdivided by means of conduits and channels of the type described. The subdivided panel may be employed as the innermost panel 'and refrigeration means can be included in one or more of the conduits 3d in this event. Furthermore, it is contemplated .that a refrigerated cabinet employing the subdivided panel principle could be provided without including any separate circulating streams.

It is also proposed that dehumidifying means be included within at least one of the conduits 35. The dehumidfying means should be included in the conduit which carries the coldest stream which is still maintained r above freezing.

It will also be appreciated that one of the primary advanta ges of employing the conduit and channel structures described consists in the ability of the structure to provide for division of air streams into several portions without necessitating the use of an extremely large construction. The side-by-side disposition of the conduits and the particular arrangement of the openings in the sheets defining the channels permit the utilization of a large number of streams, each being circulated by a fan or the like. By providing a plurality of circulating streams in this manner, control of the speed and relative temperatures of the various portions thereof is also possible, and, as explained above, such control permits significant increases in the eiliciency of operation of the apparatus.

From the above description it will be understood that the operation of the refrigerated cabinet described is to be carried out in accordance with certain principles referred to in the various co-pending applications mentioned above. Specifically, it is contemplated that the circulating means being operated in a manner such that a maximum amount of laminar flow characterizes the air streams crossing the access opening of the housing. The streams are preferably moved in a manner such that a minimum of turbulence occurs therein whereby mixing at the interfaces between the various panels including the subdivided portions is largely avoided. It is also contemplated that various defrosting operations be incorporated in the operating cycle in order to achieve maximum efficiency of operation.

it will be further understood that various other modications can be made in the above described refrigerated cabinet structure which provide the characteristics of this invention without departing from the spirit thereof particularly as dened in the following claims.

That which is claimed is:

l. In a refrigerated cabinet 0f the type which defines an access opening in one wall communicating an otherwise enclosed space with the ambient atmosphere, and which is provided with a plurality of gas inlets and a plurality of gas nozzles, said inlets and nozzles extending in side-by-side relationship across opposite edges of said access opening, passages communicating said inlets and nozzles, means for circulating gas through said passages, and refrigeration means adapted to refrigerate the gaseous stream in at least one of said passages, the improvement wherein said passages include channels each communicating with one of said inlets and nozzles, each of said channels extending transversely across said cabinet and being situated in a plurality of levels with the first level located adjacent the inner wall of said cabinet and the remaining levels being located outwardly thereof, said channels being adapted to handle gas passing between the respective nozzles and inlets, and a plurality of conduits communicating with at least some of said channels and connecting the panels for respective inlets and outlets, said conduits being situated in side-by-side relationship in a row which extends transversely across said cabinet.

2. A refrigerated cabinet in accordance with claim l wherein circulating means are situated in at least some of said conduits.

3. A refrigerated cabinet in accordance with claim 2 wherein the circulating means in said conduits are adapted to move the gaseous streams at diterent speeds through said conduits and across said access opening.

4. ln a refrigerated cabinet of the type which defines an access opening in one wall communicating an otherwise enclosed space with the ambient atmosphere, and which is provided with a plurality of gas inlets and a plurality of gas nozzles, said inlets and nozzles extending in side-by-side relationship across opposite edges of said access opening, passages communicating said inlets and nozzles, means for circulating gas through said passages, and refrigeration means adapted to refrigerate the gaseou stream in at least one of said passages, the improvement wherein said passages include channels each communica*- ing with one of said inlets and nozzles, each of said channels extending transversely across said cabinet to handle gas passing between the respective nozzles and inlets, said channels being delined by a plurality of sheets having openings therein, a plurality of conduits, said openings communicating with said conduits to thereby connect the respective inlets and outlets, said conduits being situated in a row which extends transversely across said cabinet.

5. A refrigerated cabinet in accordance with claim 4 including spacer means located adjacent each of said openings for maintaining said sheets in spaced-apart relationship, and means adjacent said openings for sealing the channels delined by said sheets with respect to each other.

6. A refrigerated cabinet in accordance with claim 5 .wherein said spacer means comprise annular members which also serve as said sealing means` 7. In a refrigerated cabinet of the type which defines anaccess opening in one Wall communicating an other- Wise enclosed space with the ambient atmosphere, and which is provided with a plurality1 ot gas inlets and a plurality of gas nozzles, said inlets and nozzles extending in side-by-side relationship across opposite edges of said access opening, passages communicating said inlets and nozzles, means for circulating gas through said passages, refrigeration means adapted to refrigerate the gaseous stream in at least the innermost one of said passages, the improvement wherein the passage adiacent said innermost passage is subdivided into a plurality of channels each communicating with one or said inlets and nozzles, each of said channels extending transversely across said cabinet to handle gas passing between the respective nozzles and inlets, and a plurality of conduits communicating with at least some of said channels and connecting the channels for respective inlets and nozzles, said conduits being situated in a row which extends transversely across said cabinets, said circulating means being adapted to move streams of gas across said access opening in the form of panels which are characterized by a high degree of laminar llow.

8. A refrigerated cabinet in accordance with claim 7 wherein said innermost passage and each of said conduits is provided with circulating means to thereby enable control of the speed of the respective laminar panels issuing from the nozzles of said conduits.

9. A refrigerated cabinet in accordance with claim 8 wherein the circulating means in said conduits are operated to move said streams at different speeds with the panel closest to the interior of the cabinet moving at the greatest speed and with progressively decreasing speeds in the panels moving adjacent thereto.

li). A refrigerated cabinet in accordance with claim 7 wherein said channels are defined by a plurality of sheets, said sheets having openings therein communicating said channels with said conduits, and including spacer means located adjacent each of said openings mounting said sheets in spaced-apart relationship with means located adjacent said openings for sealing the channels dened by said sheets with respect to each other.

ll. A refrigerated cabinet in accordance with claim l0 wherein said spacer means comprise annular members which also serve as said sealing means.

l2. A refrigerated cabinet in accordance with claim l0 including sleeve means extending from said openings toward said conduits to form said sealing means, at least a portion or" said sleeve means comprising a flexible section.

13. A refrigerated cabinet in accordance with claim lt) wherein said sheets extend from said inlets downwardly to the bottom of said cabinet and from said nozzles upwardly and rearwardly to the back of said cabinet, said conduits extending along the bottom and up the back wall of said cabinet and meeting said sheets at approximately right angles.

i4. A refrigerated cabinet in accordance with claim 7 including butler means extending across said channels between said nozzles and said conduits, said butler means being adapted to provide for uniform lateral distribution of streams passing through the nozzles communicating with the channels.

l5. A refrigerated cabinet in accordance with claim 7 including a third passage disposed outwardly of the subdivided passage and conning a separate stream of air, said second stream being circulated through Contact with the stream adjacent thereto.

i6. in a refrigerated cabinet or" the type which denes an access opening in one wall communicating an otherwise enclosed space with the ambient atmosphere, and which is provided witlra plurality of gas inlets and a plurality of gas nozzles, said inlets and nozzles extending in side-by-side relationship across opposite edges of said access opening, passages communicating said inlets and nozzles, means or circulating gas through said passages, and refrigeration means adapted to refrigerate the gaseous stream in at least one of said passages, the improvement wherein said passages include channels each communicating with one ot said inlets and nozzles. each of said channels extending transversely across said cabinet to handle gas passing between the respective nozzles and inlets, and a plurality' of conduits communicating with at least some of said channels and connecting the panel for respective inlets and outlets, said conduits being situated in a row which extends transversely across said cabinet, and including butler means extending across said channels between said nozzles and said conduits, said butler means being adapted to provide for uniform lateral distribution of streams passing through the nozzles communicating with the channels.

References Cited in the file of this patent UNITED STATES PATENTS

Claims

1. IN A REFRIGERATED CABINET OF THE TYPE WHICH DEFINES AN ACCESS OPENING IN ONE WALL COMMUNICATING AND OTHERWISE ENCLOSED SPACE WITH THE AMBIENT ATMOSPHERE, AND WHICH IS PROVIDED WITH A PLURALITY OF GAS INLETS AND A PLURALITY OF GAS NOZZLES, SAID INLETS AND NOZZLES EXTENDING IN SIDE-BY-SIDE RELATIONSHIP ACROSS OPPOSITE EDGES OF SAID ACCESS OPENING, PASSAGES COMMUNICATING SAID INLETS AND NOZZLES, MEANS FOR CIRCULATING GAS THROUGH SAID PASSAGES, AND REFRIGERANT MEANS ADAPTED TO REFRIGERATE THE GASEOUS STREAM IN AT LEAST ONE OF SAID PASSAGES, THE IMPROVEMENT WHEREIN SAID PASSAGES INCLUDE CHANNELS EACH COMMUNICATING WITH ONE OF SAID INLETS AND NOZZLES, EACH OF SAID CHAN-