EP1582829A1

EP1582829A1 - Improved refrigeration cabinet

Info

Publication number: EP1582829A1
Application number: EP05251854A
Authority: EP
Inventors: Suyash Baichoo; Adam Harrison; Lee Martin
Original assignee: Alan Nuttall Ltd
Current assignee: Alan Nuttall Ltd
Priority date: 2004-03-29
Filing date: 2005-03-24
Publication date: 2005-10-05

Abstract

The present invention relates to an open fronted refrigeration cabinet (10) having a refrigerated space accessible through an open front of the cabinet (10), the cabinet (10) further having a vapour refrigeration apparatus including a condenser (26), a compressor 22 and an evaporator (24) in fluid communication with one another, wherein the condenser (26) is provided on an outer rear wall (14) of the cabinet and shrouded by a duct (34).

Description

The present invention relates to refrigeration cabinets and in particular to open fronted refrigeration cabinets of the type utilised in retail premises to store and display chilled goods.
Open fronted refrigeration cabinets have been utilised in retail premises for a number of years. Typically chilled goods, for example dairy products such as cheese and milk, are supported on shelves provided within the interior of the cabinet. As the cabinet is open fronted, i.e. it is not provided with a door which may be used to restrict access to the interior, then the products are readily viewable by a potential buyer. The refrigeration apparatus of the cabinet operates to maintain the cabinet interior at a predetermined reduced temperature, and typically is configured to produce a downwardly directed cold air curtain across the open front. The lack of a door further eliminates the problems associated condensation and frosting which may reduce the visibility through glazed portions of such a door. The refrigeration apparatus is typically provided in the base of the cabinet and requires periodic inspection and maintenance.
According to the present invention there is provided an open fronted refrigeration cabinet having a refrigerated space accessible through an open front of the cabinet, the cabinet further having a vapour refrigeration apparatus including a condenser, a compressor and an evaporator in fluid communication with one another, wherein the condenser is provided on an outer rear wall of the cabinet and shrouded by a duct.
The provision of the condenser on the rear wall of the cabinet allows a larger condenser to used in comparison to known cabinets of similar size where the condenser is typically situated in the base. The condenser is also spaced upwardly from the base and hence is less susceptible to becoming coated with material such as dust and dirt which may be present on the surface upon which the cabinet rests, in use. The use of a larger condenser allows the size and spacing of the fins thereof to be increased which in turn reduces the possibility of dust being retained thereon.
The provision of the duct serves both to promote an air current over the condenser and to protect the condenser from damage. Advantageously the duct is removable to allow access to the condenser. The duct is provided with an inlet in a lower region thereof and an outlet in an upper region thereof. The inlet permits the admission of cool air to the duct, while the outlet directs air warmed by the condenser upwards and away from the cabinet.
The cabinet is preferably further provided with an evaporator condensate collection and disposal arrangement comprising a collection tray positioned to receive condensate released from the surface of the evaporator and a heating means positioned in a lower portion of the collection tray, wherein the heating means comprises a portion of a refrigerant communication line extending between the compressor and the condenser.
The positioning of the refrigerant communication line in the tray permits heat energy transferred to the refrigerant by compression thereof to be used to evaporate any condensate in the collection tray. Advantageously the communication line is tightly coiled within the tray so as to provide a sufficient surface area to ensure that the condensate is evaporated without the neat for additional heat input. Condensate evaporated from the tray passes to the duct whereupon it is conveyed upwards and away from the cabinet through the outlet. The cabinet may be provided with a fan in the vicinity of the tray to generate an air current in the direction of the duct.
An embodiment of the present invention will now be described with reference to the accompanying drawings in which:
Figure 1 shows a simplified schematic side view of a cabinet according to the present invention;
Figure 2 shows a plan view of a refrigerant conduit of the cabinet of figure 1; and
Figure 3 shows a cross-sectional side view of the conduit.
Referring firstly to figure 1 there is shown an open fronted refrigeration cabinet, generally designated 10, of the type utilised in food retail establishments. The cabinet 10 comprises a base portion 12, a rear wall portion 14 and a ceiling portion 16. The cabinet 10 further includes end wall portions which have been omitted for the sake of clarity. The base 12, rear wall 14, ceiling 16 and end walls serve to partially enclose a refrigerated space 18 which is accessible via the open front 20 of the cabinet 10. Typically the rear wall 14 is provided with a number of shelves (not shown) upon which produce may be supported. A layer of thermal insulation 28 is provided in the cabinet 10 around the refrigerated space 18 to prevent the influx of heat energy into the refrigerated space 18.
The cabinet 10 is further provided with a refrigeration apparatus which includes a compressor 22, an evaporator 24 and a condenser 26 linked to one another by various refrigerant conduits. The evaporator 24 is positioned in the rear wall 14 on the refrigerated space side of the insulation 28, while the condenser 26 is mounted on the outside of the rear wall 14 on the opposing side of the insulation 28. The compressor 22 is situated in the base 12 of the cabinet on the opposite side of the insulation 28 to the refrigerated space. The compressor 22 is accessible in the base 12 via a removable panel 30. The cabinet 10 is further provided with a fan 32 operable to circulate cold air within the refrigerated space as indicated by arrows 34.
The refrigeration apparatus operates on a conventional refrigeration cycle whereby heat energy is removed from the refrigerated space 18 by the evaporation of refrigerant in the evaporator 24. The evaporated refrigerant is then compressed in the compressor 22 before being passed to the condenser 26. The heat energy gained by the refrigerant in the evaporator 24 is released as the refrigerant condenses and is passed to the air surrounding the condenser 26.
As described above, the condenser 26 is mounted on the outside of the rear wall 14 of the cabinet 10. The condenser 26 is of a conventional type comprising a finned tube. The condenser 26 is surrounded by a duct 34 having an outlet 36 at the upper end thereof. An inlet (not shown) is provided towards the base of the duct 34 below the lower edge of the condenser 26. Air heated by the condenser 26 is directed upwardly through the duct 34 and out of the outlet 36 as indicated by arrows 38. It will be appreciated that the connective effect of air being passed over the condenser 26 leads to an improvement in the heat transfer efficiency thereof. The duct 34 also acts to as a shield for the condenser 26, thereby protecting it from damage, for example during transport and installation of the cabinet 10.
The positioning of the condenser 26 on the rear wall 14 further enables a larger condenser to be used when compared to existing cabinets of a similar size. Typically the condenser is situated in the base of the cabinet where space is at a premium. By being situated in the base the condenser is susceptible to becoming coated with dust and dirt which reduce the heat transfer efficiency thereof. Subsequent cleaning of the condenser may be difficult due to its low position and access may be restricted by the presence of other system components such as the compressor and circulation fans. By providing the condenser 26 on the rear wall 14, it is less likely to be exposed to dust and dirt present upon the surface upon which the cabinet 10 rests. In the event that the condenser 26 does require cleaning, then the whole of the condenser 26 is readily accessible by the simple removal of the duct 34. The use of a larger condenser 26 also allows the spacing and size of the fins to be increased, thereby reducing the possibility of dirt and dust being trapped thereby.
The repositioning of the condenser 26 frees up space within the base 12 and thereby permits the advantageous repositioning of other system components. For example, the compressor 22 can be positioned at the front of the base portion 12 where it can be easily accessed via the removable panel 30.
A further feature of the present invention is the provision of a condensate waste water evaporator which utilised waste heat generated by the compressor. During use the evaporator 24 becomes coated with ice which must be periodically removed if the heat transfer efficiency of the evaporator 24 is not to suffer. Defrosting of the evaporator 24 is typically achieved by temporarily suspending the operation of the refrigeration apparatus and warming the evaporator 24 to melt any ice attached thereto. Warming of the evaporator may be achieved by the provision of dedicated heating elements.
In the embodiment shown the cabinet 10 is provided with a collection tray 40 positioned below the evaporator 24 to catch and retain evaporator melt water. The refrigerant conduit 42 extending between the compressor 22 and the condenser 26 passes through a lower portion of the tray 40. As will be readily understood by persons skilled in the art, the compression of the refrigerant in the compressor 22 raises the temperature of the refrigerant above that of the ambient temperature surrounding the cabinet 10. By routing the conduit 42 through the collection tray 40, the temperature increase is exploited to evaporate any water retained therein. In order to maximise the evaporation effect, the surface area of the portion of the conduit 42 within the collection tray 40 is made as large as possible. This is achieved by tightly coiling the conduit 42 within the tray 40. Advantageously the conduit 42 is configured in a flat spiral or involute shape. The conduit 42 may be configured into a plurality of flat spirals which are stacked over one another.
Figures 2 and 3 show the conduit 42 in greater detail. The conduit 42 comprises a tube having an inlet 48 in communication with the compressor 22, an outlet 50 in communication with the condenser 26, and a coiled intermediate portion 52 between the inlet and outlet 48,50. For the sake of simplicity only the inner and outer coils 54,56 of the intermediate portion 52 are shown, however it will be appreciated that the intermediate portion 52 comprises a plurality of coils in contact with one another between the inner and outer coils 54,56. More than one conduit 42 may be provided. As can be seen from figure 3 two conduits 42 may be stacked on top of one another and secured for example by a number of tack welds.
The heat energy transferred to water within the tray 40 via the conduit 42 leads to its evaporation. A fan 44 is provided in the vicinity of the tray 40 to direct an air current, indicated by arrow 46, over the tray 40. The air current 46 entrains evaporated water molecules and directs them into the duct 34 whereupon they are entrained in the upwardly directed air current generated by the condenser 26. The evaporated water is thus directed upwards and away from the cabinet 10 through the outlet 36.
By directing both air heated by the condenser 26 and moisture evaporated from the collection tray 40 upwardly and away from the cabinet 10, the possibility of it entering the refrigerated space 18 via the open from 20 of the cabinet 10 is greatly reduced.

Claims

An open fronted refrigeration cabinet having a refrigerated space accessible through an open front of the cabinet, the cabinet further having a vapour refrigeration apparatus including a condenser, a compressor and an evaporator in fluid communication with one another, wherein the condenser is provided on an outer rear wall of the cabinet and shrouded by a duct.
A refrigeration cabinet as claimed in claim 1 wherein the condenser is spaced upwardly from the base of the cabinet.
A refrigeration cabinet as claimed in claim 1 or claim 2 wherein the duct is arranged to both promote an air current over the condenser and to protect the condenser from damage.
A refrigeration cabinet as claimed in any preceding claim wherein the duct is removable to allow access to the condenser.
A refrigeration cabinet as claimed in any preceding claim wherein the duct is provided with an inlet in a lower region thereof and an outlet in an upper region thereof, wherein the inlet permits the admission of cool air to the duct, and the outlet directs air warmed by the condenser upwards and away from the cabinet.
A refrigeration cabinet as claimed in any preceding claim wherein the cabinet is provided with an evaporator condensate collection and disposal arrangement comprising a collection tray positioned to receive condensate released from the surface of the evaporator and a heating means positioned in a lower portion of the collection tray, wherein the heating means comprises a portion of a refrigerant communication line extending between the compressor and the condenser.
A refrigeration cabinet as claimed in claim 6 wherein the refrigerant communication line is tightly coiled within the collection tray.
A refrigeration cabinet as claimed in claim 6 or claim 7 wherein the condensate collection and disposal arrangement is configured such that condensate evaporated from the tray passes to the duct whereupon it is conveyed upwards and away from the cabinet.
A refrigeration cabinet as claimed in any of claims 6 to 8 wherein the cabinet is provided with a fan in the vicinity of the tray to generate an air current in the direction of the duct.