Supermarket refrigerator   

THIS invention relates to a supermarket refrigerator, i.e. a refrigerator suitable for use in a supermarket to keep food items cold and display those items for sale.

In conventional supermarket refrigeration systems, the refrigeration space or display cabinet in which food items are displayed for sale, and from which such items can be accessed by shoppers, is situated at the appropriate position on the sales floor while the operative components of the refrigeration circuit, including compressors, heat exchangers and the like, are situated at a remote position. This is typically in a separate refrigeration room away from the sales floor.

Such arrangements require substantial lengths of piping to be laid, properly levelled, insulated and embedded in the floor slab of the supermarket to extend from the refrigeration space/display cabinet to the remote circuit components. This can contribute considerably to the overall cost, complexity and efficiency of the system.

It is an objective of the present invention to provide a substantially more compact supermarket-type refrigerator.

SUMMARY

According to the invention there is provided a refrigerator suitable for supermarket use, the refrigerator comprising: a refrigeration space for accommodating refrigerated food items; a thermally insulated bottom panel beneath the refrigeration space, such panel having a relatively high, laterally extending front portion, a relatively low, laterally extending rear portion and an intermediate, upstanding wall portion joining the front and rear portions, the intermediate wall portion separating a front compartment located forwardly of the intermediate wall portion beneath the front portion from a rear compartment located rearwardly of the intermediate wall portion above the rear portion, a compressor and associated components of a refrigeration circuit in the front compartment; an evaporator unit located to the rear of the rear compartment to receive refrigerant from the refrigeration circuit components in the front compartment; and at least one air distribution fan arranged to direct air along an air flow path from the refrigeration space, through the rear compartment, through the evaporator unit and back into the refrigeration space.

The refrigeration apparatus is accordingly a self-contained unit in which the components of the refrigeration circuit are located compactly beneath and behind the refrigeration space, thereby obviating the need for remote siting of such components.

In the preferred embodiments, the bottom panel is made in one piece and comprises a thermally insulating core in a moulded skin of plastics material. The intermediate wall portion of the bottom panel is preferably inclined, at an acute angle, typically 45°, to the horizontal while the front and rear portions of the bottom panel are generally horizontal.

The front compartment typically accommodates a compressor, a heat exchanger and a receiver in side by side relationship. The heat exchanger is preferably arranged to operate in counter-flow mode to provide a compact construction. In practice, the heat exchanger may comprise a relatively small diameter inner pipe for conveying refrigerant in counter flow to cooling water conveyed in a water jacket between the inner pipe and a relatively large diameter outer pipe within which the inner pipe is located.

The air distribution fan(s) may be mounted in a fan support panel between the intermediate wall portion and the evaporator unit.

The preferred refrigerator includes an upstanding back panel at the back of the refrigeration space and an upstanding rear panel situated at the rear of the refrigeration space and spaced forwardly of the back panel, the space between the rear and back panels forming part of the air flow path and the rear panel having openings therein for directing cooled air forwardly through the panel from the air flow path into the refrigeration space.

The air flow path conveniently includes a diffuser, located above the refrigeration space and communicating with the space between the rear and back panels for directing air downwardly at the front of the refrigeration space.

The upper surface of the rear portion of the bottom panel may have front and rear sections sloping downwardly to a central drainage channel.

In another version of the invention the refrigerator may include a glass door for closing the front of the refrigeration space.

In yet another version of the invention, the refrigerator comprises a pair of back to back refrigeration spaces, typically with open tops and with an upstanding wall between them, a thermally insulated bottom panel beneath each refrigeration space, each bottom panel defining a front compartment, a compressor and associated components of a refrigeration circuit in at least one of the front compartments, an evaporator unit within the upstanding wall between the refrigeration spaces, and air distribution fans for each refrigeration space.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which:

FIG. 1 shows a front perspective view, partly broken away, of an open front supermarket refrigerator according to this invention;

FIG. 2 shows a diagrammatic, sectional side view of the refrigerator seen in FIG. 1;

FIG. 3 illustrates components of the refrigeration circuit of the refrigerator seen in FIG. 1;

FIG. 4 illustrates the counter-flow heat exchanger of the refrigeration circuit;

FIG. 5 shows a diagrammatic side view of a glass door supermarket display refrigerator according to the invention;

FIG. 6 shows a diagrammatic side view of an open top, back-to-back cabinet style supermarket refrigerator according to the invention;

FIG. 7 shows another diagrammatic, sectional side of the open front supermarket refrigerator of in FIG. 1, illustrating how the refrigeration space is illuminated.

FIGS. 1 and 2 show an open-front supermarket refrigerator 10 according to the invention. As is conventional in refrigerators of this general type, the refrigerator 10 has a refrigeration space 12 in which there is a number of vertically spaced, horizontal shelves 14 on which refrigerated food items can be displayed for sale to supermarket customers.

The term “food item” as used in this specification includes all manner of comestible products, including solid items such as butter, fruit and so on as well as liquid products such as milk, yoghurt and so on.

The refrigeration space 12 has a removable, lower shelf 14.1 located over a bottom panel 16. The lower shelf 14.1 is omitted from FIG. 1. The bottom panel 16 is of moulded plastics construction and is thermally insulated. It may for instance have a thermally insulating core of polystyrene, polyurethane or the like encapsulated in a moulded skin of suitable plastics material.

The bottom panel 16 has a relatively high, horizontal front portion 16.1, a relatively low, horizontal rear portion 16.3, an intermediate, upstanding wall portion 16.2 joining the rear edge of the front portion to the front edge of the rear portion and a vertical rear portion 16.4. The wall portion 16.2 is arranged at an acute inclination, in this case about 45°, to the horizontal.

There is a horizontal base structure 18, which rests on the floor, beneath the bottom panel 16. The rear portion 16.3 of the bottom panel is mounted on the base as illustrated. The front edge of the front portion 16.1 is mounted over a front panel 20.

The base 18, front panel 20, front portion 16.1 and wall portion 16.2 define a front compartment 22.

The shelves 14 extend forwardly from an insulated, inclined rear panel 24 mounted forwardly of the vertical back panel 26 of the refrigerator. This back panel is partially provided by the rear portion 16.4 of the bottom panel 16. A fan support panel 32 extends between the wall portion 16.2 and a supporting bracket 34. The evaporator unit of the refrigeration circuit, designated 30, is situated against the vertical rear portion 16.4 of the bottom panel 16.

The rear portion 16.3 of the bottom panel 16, the wall portion 16.2, the fan support panel 32 and the evaporator unit 30 define between them a rear compartment 36. Air distribution fans 38 are mounted in ducts 40 spaced apart in the fan support panel 32 which is situated beneath the shelf 14.1.

The front compartment 22 accommodates mechanical components of the refrigeration circuit, generally designated 41. The components include a compressor 42, counter-flow heat exchanger 44 and receiver or accumulator 46. As shown in FIG. 3, these components are arranged in a compact, side by side configuration within the front compartment. In this Figure the bottom panel 16 is removed and only upright end and bulkhead panels 48 are shown. The panels 48 close off the ends of the compartment 22 and subdivide it into smaller sub-compartments. They also provide support to bottom panel 16 at intervals along its length.

In use, the fans 38 cause air to flow along the path indicated by the numerals 49. As illustrated, the air is initially directed downwardly in the compartment 36, then flows upwardly through the evaporator unit 30 which cools it, and into the space 28 between the panels 24 and 26. Some air flows forwardly between the shelves 14 through openings in the panel 24, thereby cooling food products on the shelves. Remaining air which reaches the top of the space 28 is directed downwardly, in the form of an air screen 49.1, by a diffuser 47.

The diffuser may have a honeycomb structure and consist of a great number of slender, tubular members arranged in a nested configuration.

At the bottom of the refrigeration space 12, the air is taken into a space beneath the shelf 14.1 and from there is again directed downwardly into the compartment 36, whereafter the cycle repeats itself.

As indicated above, the heat exchanger 44 is of counter-flow design. As shown also in FIG. 4, the heat exchanger has spaced apart brackets 50 supporting the ends of relatively large diameter outer pipes 52 within which there are relatively small diameter inner pipes 54. Cooling water, piped from a remote source, is circulated through a water jacket which exists between the inner and outer pipes from an inlet 56 to an outlet 58 in counterflow to refrigerant which is pumped through the inner pipes 52 from an inlet 60 to an outlet 62. As in a normal compressor-driven refrigeration circuit, the refrigerant is in gaseous form on introduction to the heat exchanger through the inlet 60 and is cooled and condensed to liquid form by the time it exits through the outlet 62. After passage through the heat exchanger the refrigerant is received by the receiver/accumulator 46 from which it is passed via an expansion valve 63 to the evaporator unit 30 where it serves, in the conventional manner, to withdraw heat from the air flow directed into the refrigeration space.

An important advantage of the illustrated embodiment is the fact that the relevant components of the refrigeration circuit are located side by side in the front compartment 22, beneath the refrigeration space. The compact arrangement of these components, and the ability to accommodate them in the front compartment 22 is to some extent made possible by the fact that the circuit makes use of an efficient counterflow heat exchanger which occupies little space in a vertical sense.

Another advantage of the illustrated embodiment arises from the fact that the fan 38 is mounted at a relatively low level and is arranged to direct at least some of the air flow downwardly onto the inclined wall portion 16.3 of the bottom panel. The inclination of the wall portion 16.3 assists in generating a smooth and efficient air flow distribution pattern in the refrigerator.

The location of the refrigeration circuit components in the front compartment obviates the need for remote location of such components as in conventional supermarket refrigeration installations. As a result there is no need for refrigerant piping to be laid and embedded in the floor slab of the supermarket, and it is anticipated that this will considerably reduce the overall complexity and cost of the refrigeration installation.

The compressor 42 is mounted on a sliding tray 65 by means of which it can be pulled forwardly, out of the compartment 22, for maintenance purposes.

In this embodiment of the invention, the evaporator unit 30 is of two stage design. It is described in more detail in a copending patent application filed simultaneously with the present application by the same applicant.

The rear portion 16.3 of the bottom panel 16 has an upper surface with counter-sloping front and rear sections 70.1 and 70.2 leading to a central channel 70.3. This feature is provided to facilitate drainage of liquids from the refrigeration space 12. The drainage feature is described in more detail in another copending patent application filed simultaneously with the present application by the same applicant.

The refrigerator 72 seen in FIG. 5 differs from the refrigerator 10 only in that it has a glass door 74 closing the front of the refrigeration space. The door may be of pivoted or sliding type. In all other respects, the refrigerator 72 operates in the same manner as the refrigerator 10.

The refrigerator 76 seen in FIG. 6 also operates in the same way as the refrigerator 10. It is however of an open top, back-to-back type suitable for display and refrigeration of, for example, frozen food items. The refrigerator 76 effectively comprises two refrigerators of FIG. 10 type in a back-to-back, open top configuration. It may however make use of a single evaporator unit mounted in a central space 78 between the two refrigeration spaces 12. In this case, the air flow pattern is indicated by the numerals 79.

Whereas the refrigerators seen in FIGS. 1 and 5 will typically be for medium temperature applications, for example for dairy and fresh meat products, the refrigerator of FIG. 6 will typically be for low temperature applications, for example for frozen products.

FIG. 7 shows how a refrigerator of the type illustrated in FIG. 1 can be illuminated. As illustrated, the front edge of the bottom panel 16 has an upward extension 80 carrying a horizontally oriented fluorescent tube 82 in a tube compartment 84 fitted with a lens 86 designed to project the light in the illumination pattern illustrated by the lines 88. In this way, the light is prevent from shining directly into the eyes of customers observing the food items on the shelves 14.

The roof 90 of the refrigerator 10 has an extension 92 in which several fluorescent tubes 94 are mounted to direct light downwardly onto the shelves. In this case the light is prevented from shining directly into the eyes of customers by a front cowling or hood 96 mounted on the extension 92. As illustrated lenses 98 (only one shown), similar to the lens 86, can also be provided to control the light distribution pattern provided by the tubes 94.

Referring in particular to FIG. 1 it will be understood that the bottom panel 16 extends for the full length of the refrigerator. Other panels may however extend for only part of the length of the refrigerator, the exact configuration and number of panels depending on the actual refrigerator size. As also shown in FIG. 1, there are multiple fans 38 spaced apart along the length of the refrigerator. In refrigerators which are relatively short, there may be less fans while in longer refrigerators there may be more.