GB2387898A

GB2387898A - Cold storage appliance

Info

Publication number: GB2387898A
Application number: GB0316698A
Authority: GB
Inventors: Ian David Wood
Original assignee: Applied Design and Engineering Ltd
Current assignee: Applied Design and Engineering Ltd
Priority date: 2000-09-13
Filing date: 2001-03-13
Publication date: 2003-10-29
Anticipated expiration: 2021-03-13
Also published as: GB0316698D0; CN100417879C; GB2387898B; CN1808024A; ZA200307075B; ZA200307078B; ZA200307079B

Abstract

A cold storage appliance 332 includes at least one container 16, and a structure defining a vapour-sealable container compartment 344 from which the container can be withdrawn to open the container and afford access to its interior and to which the container can be returned to close the container for cold storage of any items within the container. Barrier means such as a bellows 374 is attached to the rear face of each container 16. The cross-section of each bellows 374 substantially matches the cross-sectional shape and size of the respective container compartment 344. The rear end of the bellows is sealed around its periphery to the surrounding walls of the container compartment 344. The open end of each bellows 374 communicates directly with the surrounding atmosphere so that fresh air is drawn into the bellows 374 as the drawer 4 opens and exhausts as the drawer closes. Accordingly, there is no mixing between the incoming air in the bellows 374 and the air that is or was in the container compartment 344.

Description

IMPROVEMENTS IN OR RELATING TO COLD STORAGE

The invention herein relates to the art of cold storage, including appliances such as refrigerators and freezers for storing foodstuffs and other perishables. Other applications 5 of the invention include storage of chemicals and medical or biological specimens. The invention also finds use in mobile applications, for example in the bulk transport and storage of perishable goods.

The invention develops and adds to the various features of the Inventor's co-pending 10 International Patent Application No. PCT/GB00/03521, the contents of which are incorporated herein by reference. As in that specification, the invention can be applied to

storing any items within a cooled environment, such as in a refrigerated goods vehicle.

The term 'appliance' is therefore to be construed broadly, extending beyond fixed domestic devices into industrial, scientific and mobile applications.

Briefly to recap the introduction of PCT/GB00/03521, the advantages of storing foodstuffs

and other perishable items in refrigerated and segregated conditions have long been known: refrigeration retards the degradation of such items and segregation helps to prevent their cross-contamination. Accordingly, modern cold-storage appliances such as 20 refrigerators and freezers are usually compartmentalized, albeit not often effectively, so that a user can store different types of food in different compartments. All such appliances have the additional aim of maximising their energy efficiency.

US Patent No. 1,337,696 to Ewen is a prior art document cited as technological

25 background against PCT/GB00/03521. Ewen speaks of segregation between refrigerated

drawers contained in a surrounding cabinet and employs refrigerating units placed immediately and closely above each drawer... so that said drawer may in effect be said to be closed against said refrigerating unit'. However, there has to be a gap left between the drawer and the refrigerating unit if the drawer is going to open. That gap will promote 30 icing as moist air within the cabinet migrates into the drawer and the water vapour condenses and freezes. The smaller the gap, the sooner the accumulating ice will prevent drawer movement. If a larger gap is tried instead, there will be a greater spillage of air and hence the refrigerator will be less energy-efficient and more susceptible to cross

-2 contamination. That aside, the spillage of cold air in Ewen lowers the temperature within the cabinet around the drawers, and so increases the likelihood of condensation on the drawers when S opened. It will be noted that cold air spilled in this way can fall freely behind the drawers within the cabinet and so expose the exterior of the drawers to air substantially below ambient temperature. Certain design details of Ewen worsen this effect. For example, the bottom wall of the Ewen unit is an efficient insulator which will significantly reduce the surface temperature of the drawers. Also, the internal divisions between the drawers do not 10 allow for ambient heat transfer to the drawers but only for heat transfer between the drawers, thus promoting drawer-to-drawer temperature equalisation over time. Left for long periods, or even overnight, large parts of the external surface of each drawer will fall to temperatures significantly below ambient dew point. Condensation or ice will therefore form on those surfaces as soon as the drawers are opened; similarly, if the drawers are 15 removed and left outside the appliance, they will start to 'sweat' with condensation.

Opening and closing a drawer within a sealed cabinet in Ewen acts like a piston, alternately applying bow negative and positive pressures to adjacent areas. This promotes air transfer through the drawer opening at the front of the cabinet, which can displace cold 20 treated air in a drawer, and within the cabinet itself. An over-sized cabinet would reduce the piston effect but would also be wasteful of space. Conversely, a more space-efficient close-fitting cabinet may decrease the displacement of cold treated air, and so reduce the burden of cooling the warmer air that takes its place, but it will increase resistance to opening and closing the drawer.

Cold air spillage aside, the gap inevitably left between a drawer and its associated lid in prior art arrangements is large enough to allow the passage of enzymes, spores and other

airborne contaminants. Also, Ewen discloses a common interconnecting drain and this too would allow free transfer of contaminants between each drawer, particularly under the 30 aforementioned piston action.

It is against this background that Me present invention has been devised.

-3 The invention resides in a cold-storage appliance including: at least one container, a structure defining a vapour-sealable container compartment from which the container can be withdrawn to open the container and afford access to its interior and to which the 5 container can be returned to close the container for cold storage of any items within the container; and barrier means adapted to advance and to retract along the container compartment as the container is being withdrawn from and returned to the container compartment, while maintaining a vapour seal so as (i) to separate from the interior of the container air drawn into the container compartment by withdrawal of the container and (ii) 10 to displace that air from the container compartment when the container is returned to the container compartment.

The invention mitigates the piston effect and its risk of crosscontamination by maintaining a vapour seal between the interior of the container and air within the 15 compartment vacated by the container. For example, the barrier means can be a bellows extensible along and sealed to the surrounding walls of the container compartment.

The bellows may be attached to the rear of the container, and may be closed at its forward end and open at its rearward end. The rearward end of the bellows may be sealed around 20 its periphery to the surrounding walls of the container compartment to form a vapour barrier. The open end of the bellows suitably communicates with the surrounding atmosphere so that atmospheric air is drawn into the bellows as the container opens and exhausts as the container closes.

25 In order that the invention can be more readily understood, reference will now be made, by way of example only, to the accompanying drawings in which: Figures l(a), l(b) and l(c) are a front elevation and two sectional views respectively of a cold-storage appliance that is functionally akin to the 30 aforementioned Ewen prior art but addresses many of its problems; and

Figure 2 is a sectional side view of two drawers of the appliance of Figures l(a),

-4 l(b) and l(c) fitted with bellows to minimise air transfer into the drawer compartments during drawer opening and closing.

Referring firstly to Figure 1 (a), this is a front elevation of a coldstorage appliance 332 that 5 is functionally akin to the aforementioned Ewen prior art but addresses many of its

problems. In outward appearance, the appliance of Figure l(a) is a benchtype appliance having drawers 4, control panel 274 and refrigerator engine 272 under a worktop 270.

Figure 1 (b) - a section on line A-A of Figure 1 (a) - shows that each drawer 4 comprises a lid 22 within the cabinet and a bin 16 movable forwardly from the cabinet on telescopic 10 runners 74. Figure l(c) - a section on line B-B of Figure l(a) - shows those runners 74 beside the bin 16.

Like Ewen, the bin 16 simply slides horizontally past the close-fitting lid 22. The gap between the bin 16 and the lid 22 that is therefore necessary requires the creation of a 15 complete external vapour barrier around the compartment that houses each drawer, so as to overcome the associated moisture transmission and cross-contamination problems.

Thus, as Figure l(b) shows, the front panel 118 of each drawer extends beyond the corresponding drawer aperture defined between the lids 22 or between a lid 22 and a bottom panel 334. The overlapping portion of each front panel 118 has vertical magnetic 20 seals 336 on its rear face that, when the drawer 4 is closed, seal by flexible resilience and magnetic attraction against the opposed front faces of the lids 22 and/or the bottom panel 334 as appropriate. The drawer compartments are also sealed from each other; this applies especially to penetrations and service connections that run between neighbouring drawer compartments. It also applies to water drainage from the drawer compartments: separate 25 drain lines (not shown) should be run individually from each compartment and should each have in-line water traps.

Figure 1 (c) also shows L-section bin supports 338 depending from the runners 74 to cradle the bin 16 in a removable manner. Each drawer compartment should be of the minimum 30 volume that allows access to the bin 16 and the associated runners 74.

The invention provides a way to minimise cross-contamination between drawer

-s- compartments by maintaining a vapour barrier effective throughout the range of movement of a drawer 4. Figure 2 shows a way of achieving this and depicts two drawers 4 of an appliance, one above the other. The upper drawer 4 is closed and the lower drawer 4 is open and it will be noted that each is fitted with a bellows 374 attached to the rear face 5 of the bin 16 in each drawer 4. The cross-section of each bellows 374 substantially matches the oblong cross-sectional shape and size of the drawer compartment 344, and each is capable of extending the full length of the drawer compartment 344 swept by the bin 16. Thus, using a piston and cylinder analogy, the bellows 374 sweeps substantially all of the volume of the associated drawer compartment 344.

The bellows 374 attached to the bin 16 of the upper drawer 4 is collapsed compactly behind the bin 16 in the closed upper drawer 4 but the corresponding bellows 374 of the open lower drawer 4 is fully extended. It will be appreciated that each bellows 374 is closed at its bin end and open to its rear end, and that the rear end is sealed around its 15 periphery to the surrounding walls of the drawer compartment 344 to form a vapour barrier. The open end of each bellows 374 communicates directly with the surrounding atmosphere so that fresh air is drawn into the bellows 374 as the drawer 4 opens and exhausts as the drawer 4 closes. However, there in no mixing between the incoming air in the bellows 374 and the air that is or was in the drawer compartment 344.

Claims

l CLAIMS

1. A cold-storage appliance including: 5 at least one container; a structure defining a vapour-sealable container compartment from which the container can be withdrawn to open the container and afford access to its interior and to which the container can be returned to close the container for cold storage of any items 10 within the container; and barrier means adapted to advance and to retract along the container compartment as the container is being withdrawn from and returned to the container compartment, while maintaining a vapour seal so as (i) to separate from the interior of the container air drawn 15 into the container compartment by withdrawal of the container and (ii) to displace that air from the container compartment when the container is returned to the container compartment.

2. The appliance of Claim 1, wherein the barrier means is a bellows extensible along and

20 sealed to the surrounding walls of the container compartment.

3. The appliance of Claim 2, wherein the bellows is attached to the rear of the container.

4. The appliance of Claim 2 or Claim 3, wherein the bellows is closed at its forward end 25 and open at its rearward end.

5. The appliance of Claim 4, wherein the rearward end of the bellows is sealed around its periphery to the surrounding walls of the container compartment to form a vapour barrier.

30

6. The appliance of Claim 4 or Claim 5, wherein the open end of the bellows communicates with the surrounding atmosphere so that atmospheric air is drawn into the bellows as the container opens and exhausts as the container closes.

7. A cold-storage appliance, substantially as hereinbefore described with reference to or as illustrated in Figure 2 of the accompanying drawings.