Freezer cabinet and method for adapting a freezer cabinet

Abstract

Disclosed is a freezer cabinet (10) for storing frozen confectionery products, the freezer cabinet (10) comprising a chamber having an opening substantially sealed by an upper surface panel (18, 20); and a further panel (22, 24) inside the chamber being spaced away from the upper surface panel (18, 20) and substantially parallel to the upper surface panel in at least one direction. At least part of the upper surface panel and further panel (22, 24) is transparent such that at least part of the inside of the chamber is visible through the upper surface panel and further panel. The upper and further surface panels each comprise at least one slideably openable section (18, 22) and the further panel covers less than 95% of the surface area of the opening in a horizontal plane at a height of the lowest part of the further panel.

Claims

1. A freezer cabinet for storing frozen confectionery products, the freezer cabinet comprising: a chamber having an opening substantially sealed by an upper surface panel; and a further panel inside the chamber being spaced away from the upper surface panel and substantially parallel to the upper surface panel in at least one direction; wherein: at least part of the upper surface panel and further panel is transparent such that at least part of the inside of the chamber is visible through the upper surface panel and further panel; the upper surface panel comprises at least one slideably openable section; the further panel comprises at least one slideably openable section; there being gaps between edges of the further panel and inner surfaces of sidewalls delimiting the chamber so that the cabinet comprises a continuous gap surrounding the entire further panel, the further panel covers between 50% and 95% of the surface area of the opening in a horizontal plane at a height of the lowest part of the further panel; the further panel creates a quiescent region between the upper surface panel and further panel wherein the quiescent region is in gaseous communication with air in the chamber; the sum of the thickness of the upper surface panel and the further panel is less than 90% of the height thickness of the upper surface panel, quiescent region and further panel; the chamber comprises a side wall and a coolant evaporator mounted in and/or on the side wall; and the cabinet does not comprise a forced-air cooling system.

2. The freezer cabinet as claimed in claim 1 wherein the further panel covers between 70 and 88% of the surface area of the opening.

3. The freezer cabinet as claimed in claim 1 wherein the height distance (H) between the further panel, measured from the lowest face of the further panel facing the chamber, and the highest part of the evaporator is at least 5 mm.

4. The freezer cabinet as claimed in claim 1 wherein the upper surface panel and the further panel both comprise two slideably openable sections.

5. The freezer cabinet as claimed in claim 1 wherein the slideably openable section in the upper surface panel is aligned with the corresponding slideably openable section in the further panel such that when moved parallel to one another an opening is created of about the same surface area.

6. The freezer cabinet as claimed in claim 5 wherein the slideably openable section in the upper surface panel is attached to the corresponding slideably openable section in the further panel such that the slideably openable section in the further panel remains unmoved relative to the slideably openable section in the upper surface panel when the latter is opened and closed.

7. A method of providing a freezer cabinet according to claim 1, the method comprising: providing an existing freezer cabinet comprising the chamber having the opening substantially sealed by the upper surface panel; and installing the further panel inside the chamber in an arrangement substantially parallel to but spaced away from the upper surface panel.

8. The freezer cabinet as claimed in claim 3 wherein the height distance (H) between the further panel, measured from the lowest face of the further panel facing the chamber, and the highest part of the evaporator is at least 7 mm.

9. The freezer cabinet as claimed in claim 8 wherein the height distance (H) between the further panel, measured from the lowest face of the further panel facing the chamber, and the highest part of the evaporator is at most between 8 and 40 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be illustrated by way of example and with reference to the following figures, in which:

(2) FIG. 1 is a perspective view of a freezer cabinet according to an embodiment of the invention.

(3) FIG. 2 is a perspective view of the upper surface panel and the further panel of the freezer cabinet shown in FIG. 1, in both an open (top drawing) and closed (bottom drawing) state.

(4) FIG. 3 shows a schematic cross-section of the freezer cabinet of FIG. 1 and equipped with a skin evaporator.

(5) FIG. 4 shows a schematic cross-section of the freezer cabinet of FIG. 3 in an orthogonal direction to the section of FIG. 3.

(6) FIG. 5 shows a schematic cross-sectional view of the freezer cabinet of FIG. 1 and equipped with a roll-bond evaporator.

(7) FIG. 6 shows a schematic cross-section of the freezer cabinet of FIG. 5 in an orthogonal direction to the section of FIG. 5.

(8) FIG. 7 is a perspective view of a freezer cabinet according to another embodiment of the invention.

(9) FIG. 8 is a perspective view of the upper surface panel and the further panel of the freezer cabinet shown in FIG. 7, in both an open (right-hand drawing) and closed (left-hand drawing) state.

DETAILED DESCRIPTION

(10) FIG. 1 shows an external view of a freezer cabinet (10) with a rectangular base (13), such as a Nucab VT300 freezer cabinet—Rio H 125G, 291 litres.

(11) The rectangular base (13) along with side walls (12, 14) and an upper surface (16) delimit the chamber in which frozen confections, such as ice cream, are stored and displayed. The upper surface (16) is split into two halves made up of a lower slideably openable section (18) which slides just under an upper section (20) of the upper surface. The upper section (20) also acts as a slideably openable section and can slide over the lower section (18). Both sections (18, 20) are each made of a single sheet of reinforced glass.

(12) Unlike a typical cabinet, the cabinet in FIG. 1 is modified by introducing a further panel comprising two sections (22, 24) parallel to and spaced apart from both the lower openable section (18) and upper openable section (20) of the upper surface respectively. The further panels are also conveniently formed of glass.

(13) As can be seen in FIG. 2, not only does the lower openable section (18) slide just under the upper openable section (20) of the upper surface (16) but further section (22) also slides just above the other further section (24). When the opening is closed, there exists a quiescent region of air between the upper surface (16) and the further sections (22, 24).

(14) The further section (22) is fitted by attaching it by struts (26) to the lower openable section (18) of the upper surface (16). In this way further panel (22) can be slideably moved together with lower openable section (18). In a similar manner the other further panel (24) is attached to upper openable section (20) by struts (30). Therefore the sections are openable by sliding across without disturbing most of the air in quiescent region.

(15) Additionally the spacing of the further panels (22, 24) from the upper surface (16) could be modified by modifying the height of the struts (26) and (30).

(16) In FIGS. 3 and 4 the cabinet is shown equipped with a skin evaporator (40) which comprises evaporator tubes (41) mounted on metal plates (42) and coiled around and embedded in the sidewalls (12, 14). The compressor/condensor and associated equipment are omitted from FIGS. 3 and 4 for clarity.

(17) As can be seen in FIGS. 3 and 4, the further sections (22, 24) do not cover the entire opening of the chamber. There is a continuous gap between the further sections (22, 24) and the inner surface of the sidewalls (12, 14). The further sections (22, 24) are spaced away from the two narrowest sidewalls (12) by a distance (A) and from the widest sidewalls (14) by a distance (8). The spacings (A) and (8) are selected in order that the further sections (22, 24) cover less than 95% of the surface area of the opening. Owing to the gap formed by this spacing, moisture does not become trapped in the quiescent region and can migrate to and freeze on the very cold sections of the sidewalls (12, 14) in contact with the evaporator (40). This prevents or at least reduces the amount of condensation on the further sections (22, 24) which would otherwise reduce product visibility.

(18) As can also be seen in FIGS. 3 and 4, the lowest further panel (24) is located above the top of the evaporator (40) by a height distance (H). The top of the evaporator (40) is the top edge of the metal plate (42) on which the tubes (41) are mounted and in thermal contact. By ensuring the height distance (H) is at least 5 mm, cooling of the quiescent region can be reduced such that the air in the quiescent region maintains its thermal barrier properties. This reduces the thermal load on the freezer and also reduces the risk of condensation which would occur more readily if the further sections (22, 24) were very cold.

(19) FIGS. 5 and 6 show a similar arrangement to that in FIGS. 3 and 4 except that the skin evaporator (40) is replaced by a roll-bond evaporator (50) mounted on the sidewalls (12, 14).

(20) FIG. 7 shows an external view of another freezer cabinet (100) but this time with a circular base (113). The circular base (113) along with single wall (112) and an upper surface (116) delimit the chamber in which frozen confections, such as ice cream, are stored and displayed. The advantage of employing a freezer with a circular base is reduced heat loss owing to a low surface area for a given volume.

(21) As best seen in FIG. 8, the upper surface (116) is split into two halves made up of a lower slideably openable section (118) which slides just under an upper section (120) of the upper surface. The upper section (120) also acts as a slideably openable section and can slide over the lower section (118).

(22) Whereas the slideably openable sections (18, 20) of the rectangular cabinet shown in FIGS. 1 to 6 slide by translating along a linear path, the slideably openable sections (118, 120) of the embodiment in FIGS. 7 and 8, slide along a circular path about an axis passing vertically through the centre of the upper surface (116).

(23) The cabinet in FIG. 7 is modified by introducing a further panel comprising two sections (122, 124) parallel to and spaced apart from both the lower openable section (118) and upper openable section (120) of the upper surface respectively.

(24) As can be seen in FIG. 8, not only does the lower openable section (118) slide just under the upper openable section (120) of the upper surface (116) but further section (122) also slides just above the other further section (124). When the opening is closed, there exists a quiescent region of air between the upper surface (116) and the further sections (122, 124).

(25) The further section (122) is fitted by attaching it by struts (126) to the lower openable section (118) of the upper surface (116). In this way further panel (122) can be slideably moved together with lower openable section (118). In a similar manner the other further panel (124) is attached to upper openable section (120) by struts (130). Therefore the sections are openable by sliding around without disturbing most of the air in quiescent region.

EXAMPLES

(26) Experiments were carried out on either an AHT VT300 freezer cabinet (Rio H 125G, 291 litres) modified as shown in FIGS. 1 to 4 or a custom-built freezer cabinet employing a roll-bond evaporator similar to that described in FIGS. 5 and 6. The upper panel was formed of two glass sections, each 4 mm thick. The further panel sections were also formed of 4 mm thick glass. Low emissivity coating was applied to both the upper and lower panels. Control experiments were also performed without the presence of the further panel sections.

(27) The experiments were performed in a controlled environmental chamber (Climate Class 4). Each cabinet was allowed to reach equilibrium state with the lid closed. Each of the openable sections was then opened and closed every 5 minutes for 2 hours to simulate use in a retail environment. During the tests the power consumption was monitored and/or observations were recorded of condensation on the further sections.

(28) Tests 1 to 8

(29) The effect of the amount of area covered by the further panel was investigated using the VT300 freezer modified with further panels of different size such that the gaps between the panels and the side walls (A and B as described above) were varied. The height (H) distance was kept constant at 10 mm in these experiments. The results are shown in Table 1.

(30) TABLE-US-00001 TABLE 1 % Opening Energy Energy Conden- A B covered by Consumption Savings sation Test # (mm) (mm) further panel (kWh/24 h) (%) (Y or N) 1 N/A N/A Unmodified 1.748 0 N/A 2 0 0 100 1.311 25 Y 3 0 15 94 1.295 26 Y 4 10 15 92 1.273 27 Y 5 20 15 90 1.299 26 Y 6 30 15 89 1.301 26 Y 7 40 15 87 1.297 26 N 8 50 15 85 1.308 25 N

(31) The data in table 1 show that all of the tests using the lid modified with the further panel had much better energy efficiency than the unmodified cabinet. For test 2, where the further panel covered the entire opening, severe condensation formed on a large surface area of the further panel sections. This condensation was decreased in test 3 and progressively reduced as the amount of opening covered by the further panel was reduced. In tests 7 and 8, where less than 89% of the opening was covered, the condensation was eliminated without substantially affecting the energy efficiency gain afforded by the presence of the further panel.

(32) Test 9

(33) The effect of the positioning of the further panel relative to the evaporator was investigated using the VT300 freezer modified with further panels wherein the height (H) distance was varied. In these experiments there was no gap between the further panels and the sidewalls (i.e. both A and B were zero). The results are shown in Table 2.

(34) TABLE-US-00002 TABLE 2 Energy Consumption Energy Savings Condensation Test # H (mm) (kWh/24 h) (%) (Y or N) 1 Unmodified 1.748 0 N/A 2 10 1.311 25 Y 9 −25 1.375 21 N

(35) The data in table 2 show that when the further panel is placed below the top of the evaporator, the energy benefits are reduced. This is believed to be because the air in the quiescent region is cooled too much. No condensation was observed in test 9 as the moisture in the quiescent region was able to migrate directly to the evaporator.

(36) Tests 10 to 15

(37) The effect of the positioning of the further panel relative to the evaporator was investigated using the freezer with the roll-bond evaporator and modified with further panels wherein the height (H) distance was varied. In these experiments the gaps with the sidewalls (A) and (B) were maintained at 50 mm and 15 mm respectively. The results are shown in Table 3.

(38) TABLE-US-00003 TABLE 3 Energy Test # H (mm) Consumption (kWh/24 h) Energy Savings (%) 10 Unmodified 1.61 0 11 23 1.39 14 12 53 1.353 16 13 73 1.334 17 14 93 1.331 17 15 112 1.353 16

(39) The data in table 3 clearly show that increasing the height distance (H) improved the efficiency of the freezer, except that increasing the height above about 80 mm gave no further benefit and above 100 mm the benefit even appeared to decrease slightly.