WO2019211620A1

WO2019211620A1 - Improvements to open display refrigerators

Info

Publication number: WO2019211620A1
Application number: PCT/GB2019/051231
Authority: WO
Inventors: Paul McAndrew
Original assignee: Aerofoil Energy Limited
Priority date: 2018-05-04
Filing date: 2019-05-03
Publication date: 2019-11-07
Also published as: GB201807417D0; GB2573345A

Abstract

An open display refrigerator is provided, comprising: a refrigerated interior space, air in the refrigerated interior space being separated from air in a space exterior to the open display refrigerator by an air curtain established by a fan which blows air through an air outlet towards a corresponding air inlet which recovers air from the air curtain for recirculation to the air outlet; and a weir screen which acts as a barrier to prevent air from the air curtain spilling into the exterior space, the weir screen having a first edge proximal to the air outlet and a second edge proximal to the air inlet, the first edge being disposed such that a first portion of the air curtain passes the weir screen distal to the exterior space, and the second edge being disposed to allow the first portion of the air curtain to be recovered by a first portion of the air inlet and to allow a second portion of the air curtain that has spilled into the exterior space to be recovered by a second portion of the air inlet.

Description

Improvements to Open Display Refrigerators

The invention relates to improvements in open display refrigerators.

Open display refrigerators are commonly used in retail environments, such as supermarkets and grocery stores. An open display refrigerator allows customers to view and readily access chilled goods that are stored within the refrigerator.

This type of refrigerator has an air curtain, which is established by blowing cold air across the front of the refrigerator. The air curtain issues from an air outlet at the top of the refrigerator towards an air inlet at the bottom of the refrigerator. The air inlet recovers air from the air curtain and recirculates it to the air outlet via a cooling heat exchanger and fan.

The air curtain prevents cold air in the refrigerator from mixing with warm air exterior to the refrigerator. However, it is rather inefficient, in particular because the air curtain tends to spill out from the bottom of the refrigerator and warm air from the exterior becomes entrained into the air curtain. To overcome this problem, open display refrigerators often use a weir screen (also known as a riser), located on the base deck of the refrigerator and in front of the air inlet, to prevent the air curtain from spilling out from the bottom of the refrigerator.

Refrigerator weir screens are often substantially flat and are usually located proximal to the exterior of the refrigerator relative to the air inlet. This means that any air from the air curtain that is not captured by the interior surface of the weir screen in the first instance, for example air that hits the top edge of the weir screen and flows along the exterior of the weir screen, spills into the shop aisle, which is uncomfortable for shoppers and staff and is wasteful of energy.

Some refrigerators have cold-air retrieval systems at the lower front part of the refrigerator in order to collect cold air which spills from the refrigerator. These systems add cost to the refrigerator, require maintenance and add to running costs. It would therefore be desirable to provide an open display refrigerator, with a weir screen, which allows air from the air curtain to be captured in an efficient manner, even if the air curtain is not completely captured by the interior surface of the weir screen.

In accordance with a first aspect of the invention, there is provided an open display refrigerator comprising a refrigerated interior space, air in the refrigerated interior space being separated from air in a space exterior to the open display refrigerator by an air curtain established by a fan which blows air through an air outlet towards a corresponding air inlet which recovers air from the air curtain for recirculation to the air outlet; and a weir screen which acts as a barrier to prevent air from the air curtain spilling into the exterior space, the weir screen having a first edge proximal to the air outlet and a second edge proximal to the air inlet, the first edge being disposed such that a first portion of the air curtain passes the weir screen distal to the exterior space, and the second edge being disposed to allow the first portion of the air curtain to be recovered by a first portion of the air inlet and to allow a second portion of the air curtain that has spilled into the exterior space to be recovered by a second portion of the air inlet.

By positioning the weir screen in this manner, there is a second opportunity for air from the air curtain to be captured, when the air enters the second portion of the air inlet. This allows for more efficient air capture without the need for costly air retrieval systems, thereby overcoming the problems of spilt cold air creating an uncomfortable temperatures for shoppers and staff and of wasting energy, whilst at the same time not adding to maintenance and running costs.

The air curtain is made up of air that flows out of the air outlet. This means that the air curtain may have a core or column of faster flowing air, which may make up the first portion of the air curtain and the air curtain may also comprise two outer columns of slower flowing air, wherein the column proximal the exterior space may make up the second portion of the air curtain. Alternatively, the air curtain may comprise all the air that is bounded by an imaginary plane stretching from an edge of the air outlet to an edge of the air inlet, wherein the edge of the air outlet and the edge of the air inlet are the edges that are proximal to the exterior space. The weir screen may be positioned such that it bisects an imaginary plane extending from the air inlet and parallel to the plane that the air inlet lies in, and/or the weir screen may bisect the air inlet itself, forming a first air inlet portion proximal to the interior space relative to the weir screen and a second air inlet portion proximal to the exterior space relative to the weir screen. The weir screen may have a first edge proximal to the air outlet and a second edge proximal to the air inlet, wherein the second edge is disposed such that it bisects the air inlet, optionally in a longitudinal or diagonal manner, or is spaced apart from a line which bisects, optionally in a longitudinal or diagonal manner, the air inlet by a first distance in a direction perpendicular to the air inlet. The first distance may be anywhere from a few millimetres to a few centimetres, for example from 1 mm to 10 mm or any gradation in-between. Longitudinal means that the screen runs parallel to the air inlet along the length, or a substantial length, of the air inlet. Air from the air curtain may follow a surface of the weir screen or, alternatively may follow closely to a surface of the weir screen.

The first edge and/or second edge may be disposed in a part of the air curtain that comprises slower flowing air in normal use. I n some variations, the first edge may be disposed in a central region of the air curtain, where faster flowing air is found. It is noted that in some variations, the effectiveness of the weir screen in capturing spilled air is increased if the weir screen is disposed in a faster flowing region.

In some variations, the first portion of the air inlet and the second portion of the air inlet are equal size and/or area. In other variations, the first portion is substantially larger than the second portion.

Typically, the vast majority of the air from the air curtain will enter the first air inlet portion, however any air from the air curtain that is not captured by the weir screen in the first instance has a second opportunity to be captured in the second air inlet portion due to the positioning of the weir screen. For example, about 95% - 99% of the air recovered from the air curtain will enter the first air inlet portion and about l%-5% of the air recovered from the air curtain will enter the second air inlet portion. In other variations, the split between the first and second portions of the air inlet might be about 50%-50% or about 75%-25% or about 25%-75%.

Air from the air curtain can be drawn into the second portion by the fan that blows air through the air outlet. This may be achieved by siting a fan in a continuous duct located in the body of the refrigerator that joins the air inlet and the air outlet. Alternatively, there may be two or more fans associated with the refrigerator, with at least one fan associated with the air inlet and at least one fan associated with the air outlet.

The weir screen remains coupled to the refrigerator (i.e. it is non-removable from the refrigerator in normal use). The base of the refrigerator usually lies at the same level or lower than the lower edge of the weir screen and/or the air inlet.

The weir screen may be formed from a single piece of material or alternatively from two or more materials joined in a manner that is known in the art.

The weir screen can be curved such that the air from the air curtain can follow the curve of the weir screen into the second air inlet portion. The weir screen may introduce a shape into the flow of air from the air curtain and the air. By using a curved weir screen, the efficiency of the weir screen can be further increased, when compared to a flat weir screen, as changing the shape of the airflow causes a relative increase in the amount of air captured in the second portion of the air inlet.

In some variations the weir screen is at an angle to the air curtain or normal, wherein the normal is an imaginary line that connects the air inlet and the air outlet by the shortest distance. The weir screen may also comprise a first portion and a second portion, the first portion at an angle to the air curtain or normal and the second portion substantially vertical and meeting the first portion. In some variations, the first and second portions are continuous. In other variations, the first portion is proximate the air inlet and the second portion is proximate the air outlet. The two may be joined at an angle or by a curved join. The weir screen can have a lower edge that meets the air inlet, wherein the weir screen typically meets the refrigerator along a lower edge and the two side edges of the weir screen. Alternatively, the weir screen can have a lower edge that is spaced apart from the air inlet and typically the weir screen meets the refrigerator along the two side edges of the weir screen. The gap between the lower edge and the air inlet may be anywhere from a few millimetres to a few centimetres, for example from 1 mm to 10 m or any gradation in- between. For a variation wherein the weir screen is spaced apart from the air inlet, the first portion or a part of the first portion of the air curtain may pass under the weir screen into the second portion or a part of the second portion of the air inlet and vice versa.

The weir screen can be moveable between a retracted position in which the weir screen does not limit access to a base of the refrigerator and a deployed position in which the weir screen acts as the barrier to prevent air from the air curtain spilling into the exterior space, thereby allowing easier access to the base deck of a refrigerator so that the base deck of the refrigerator can be loaded more easily when compared to a refrigerator with a weir screen in a fixed position.

In some variations, a surface of the weir screen further comprises features to help channel the air from the air curtain, encourage air from the air curtain to follow the surface of the weir screen or to reduce vortices in the air from the air curtain. The surface features may be located on the outside surface of the weir screen, proximal to the exterior space. The surface features may comprise grooves, protrusions, surface texture such a flocking, doughnut shapes or any other geometric shape.

The weir screen may be formed from a see-through plastic such as acrylic or polycarbonate. In other variations a metallic weir screen may be used. Any suitable material known in the art is contemplated for the weir screen.

The open display refrigerator may further comprise an air curtain guide for guiding the flow of air within the air curtain and the air curtain guide may be in the form of an aerofoil. The air curtain guide may further comprise at least one light source disposed in the air curtain guide so as to illuminate the interior refrigerated storage space. The air curtain guide may further comprise a recess in which the light source is disposed. The light source may also be arranged to be flush with the surface of the air curtain guide and/or the light source may have a curved profile to substantially match that of the air curtain guide.

The air curtain guide may further comprise a front portion, wherein the front portion comprises a housing formed of a transparent plastic material for displaying at least one product label.

An embodiment of the invention will now be described with reference to the accompanying drawings, in which:

Figure 1 shows a conventional open display refrigerator without a fixed screen;

Figure 2 shows the open display refrigerator of Figure 1 fitted with a fixed screen;

Figure 3 shows an open display refrigerator with a curved screen according to an embodiment of the invention.

Figure 4 shows an open display refrigerator with a curved screen according to an embodiment of the invention.

Figure 1 shows a cross-section through a conventional open display refrigerator 1. The refrigerator has an interior space 2 which is maintained at a lower than ambient temperature. Within the interior space 2, there are five shelves 3a-3e. The refrigerator 1 establishes an air curtain by blowing cold air from an air outlet 4 towards an air inlet 5. Air inlet 5 recovers air from the air curtain and a fan (not shown) within the refrigerator 1 recirculates the air to the air outlet 4 via a cooling heat exchanger (not shown) within the refrigerator 1 which maintains the recirculated air (and hence the air blown through the air outlet 4 to form the air curtain) at a desired temperature. The desired temperature is chosen to be lower than ambient and acts to prevent cold air in the interior space 2 from mixing with warm air exterior to the refrigerator 1.

The first arrow 6 shows the general path of the air curtain flowing from the air outlet 4 to the air inlet 5 and the second arrow 7 shows how some of the air in the air curtain spills out of the refrigerator when a weir screen is not present.

Figure 2 shows a similar open display refrigerator 1 to that of Figure 1, but with a fixed weir screen 12 attached proximate the air inlet. The first arrow 6 again shows the general path of the air curtain flowing from the air outlet 4 to the air inlet 5. The second arrow 8 shows how the air that would have spilled out of the refrigerator without the weir screen 12 (like arrow 6 in Figure 1) is now retained behind the weir screen 12 and also flows into the air inlet 5.

Figure 3 shows an embodiment of an open display refrigerator 13, in accordance with the present invention. A weir screen 11 is attached such that the air inlet 5 is bisected and there is a gap 14 between the lower edge 15 of the weir screen 11 and the air inlet 5. The air curtain flows from the air outlet and a first portion of the air curtain is retained by the weir screen 11 and flows into the air inlet 5; a second portion of the air curtain flows along the exterior surface of the weir screen 11 and also into the air inlet 5.

Figure 4 shows a similar embodiment of an open display refrigerator 13 to that of Figure 3, in accordance with the present invention. A weir screen 11 is attached such that the air inlet 5 is bisected, but there is no gap 14 between the lower edge 15 of the weir screen 11 and the air inlet 5. The air curtain flows from the air outlet and a first portion of the air curtain is retained by the weir screen 11 and flows into the air inlet 5; a second portion of the air curtain flows along the exterior surface of the weir screen 11 and also into the air inlet 5.

Claims

1. An open display refrigerator comprising a refrigerated interior space, air in the refrigerated interior space being separated from air in a space exterior to the open display refrigerator by an air curtain established by a fan which blows air through an air outlet towards a corresponding air inlet which recovers air from the air curtain for recirculation to the air outlet; and

a weir screen which acts as a barrier to prevent air from the air curtain spilling into the exterior space, the weir screen having a first edge proximal to the air outlet and a second edge proximal to the air inlet, the first edge being disposed such that a first portion of the air curtain passes the weir screen distal to the exterior space, and the second edge being disposed to allow the first portion of the air curtain to be recovered by a first portion of the air inlet and to allow a second portion of the air curtain that has spilled into the exterior space to be recovered by a second portion of the air inlet.

2. The open display refrigerator of claim 1, wherein air from the air curtain is drawn into the second portion of the air inlet by the fan.

3. The open display refrigerator of claims 1 or 2, wherein the weir screen is curved such that the second portion of the air curtain follows the curve of the weir screen into the second portion of the air inlet.

4. The open display refrigerator of any preceding claim, wherein the weir screen is at an angle to the air curtain.

5. The open display refrigerator of any preceding claim, wherein the weir screen comprises a first portion and a second portion, the first portion at an angle to the air curtain and the second portion substantially vertical and meeting the first portion.

6. The open display refrigerator of any preceding claim, wherein the second edge meets the air inlet.

7. The open display refrigerator of claims 1-4, wherein the second edge is spaced apart from the air inlet.

8. The open display refrigerator of any preceding claim wherein a first and/or a second surface of the weir screen further comprises features to help channel the air from the air curtain, encourage air from the air curtain to follow the surface of the weir screen or to reduce vortices in the air from the air curtain.

9. The open display refrigerator of any preceding claim, wherein the weir screen is moveable between a retracted position in which the weir screen does not limit access to a base of the refrigerator and a deployed position in which the weir screen acts as the barrier to prevent air from the air curtain spilling into the exterior space.

10. The open display refrigerator of any preceding claim, further comprising an air curtain guide for guiding the flow of air within the air curtain.

11. The open display refrigerator of claim 10, wherein the air curtain guide is in the form of an aerofoil.

12. The open display refrigerator of claims 10 or 11, further comprising at least one light source disposed in the air curtain guide so as to illuminate the interior refrigerated storage space.

13. The open display refrigerator of any one of claims 10-12, wherein the air curtain guide further comprises a front portion, wherein the front portion comprises a housing formed of a transparent plastic material for displaying at least one product label.