Abstract
An open display refrigerator comprises a refrigerated interior space, air in the refrigerated interior space being separated from air 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. A distal region of the air outlet is occluded to leave only a region of the air outlet proximal to the interior space open, and an air curtain guide is aligned in a direction of air flow of the air curtain with an edge of the blanking plate proximal to the interior space.
Claims
1. A method, comprising: measuring a first velocity of an air curtain flowing through a first cellular matrix of air channels and emanating from an air egress of an open display refrigerator; removing the first cellular matrix of air channels from the air egress after measuring the first velocity; occluding a portion of the air egress with a blanking plate after measuring the first velocity to create a partially occluded air egress with a cross-sectional area that is smaller than the air egress before the portion of the air egress was occluded; and installing a second cellular matrix of air channels different from the first cellular matrix after occluding the portion of the air egress, the second cellular matrix configured such that the air curtain emanating from the partially occluded air egress and passing through the second cellular matrix of air channels has a second velocity equal to or lower than the first velocity.
2. The method of claim 1, wherein an outer edge of the air curtain emanating from the partially occluded air egress is aligned with an air curtain guide coupled to a shelf.
3. The method of claim 1, wherein, prior to occluding the portion of the air egress, an outer edge of the air curtain emanating from the air egress is distal to an air curtain guide coupled to a shelf.
4. The method of claim 1, further comprising aligning an air curtain guide with an outer edge of the air curtain after occluding the portion of the air egress.
5. The method of claim 1, wherein the second cellular matrix defines a second plurality of channels, each of which is larger than a channel from a first plurality of channels defined by the first cellular matrix.
6. The method of claim 1, wherein the second cellular matrix replaces the first cellular matrix.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIG. 1 shows an open display refrigerator with which the invention could be used;
(2) FIG. 2 shows a detailed view of the air outlet in an open display refrigerator according to a first embodiment of the invention;
(3) FIG. 3 shows a detailed view of the air outlet in an open display refrigerator according to a second embodiment of the invention;
(4) FIG. 4 shows a detailed view of the air outlet in an open display refrigerator according to a third embodiment of the invention; and
(5) FIG. 5 shows a detailed view of the air outlet in an open display refrigerator according to a fourth embodiment of the invention.
DETAILED DESCRIPTION
(6) FIG. 1 shows a cross-section through an open display refrigerator 1. The refrigerator has an interior space 2 that 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. A cooling unit (not shown) within the refrigerator 1 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.
(7) Also shown in FIG. 1 are aerofoils 6a-6e, each of which is fitted to the front edge of a respective one of shelves 3a-3e. As explained previously, these assist in constraining the air curtain to the desired path and prevent warm air exterior to the refrigerator 1 from being entrained into the air curtain. In this case, the air curtain runs vertically from the air outlet 4 to the air inlet 5. The aerofoils are thus aligned vertically beneath an outer edge of the air outlet 4. More generally, they will be aligned to be parallel with the direction that the air curtain is intended to follow as it runs from the air outlet 4 to the air inlet 5 and roughly coincident with the outer edge of the air curtain.
(8) In FIG. 1, the situation is acceptable because the air outlet 4 is relatively narrow. This allows the shelves 3a-3e to project far enough without interfering with the air curtain. The gap between the shelves 3a-3e and the aerofoils 6a-6e is therefore low. In the remaining figures, FIG. 2 to FIG. 5, a deeper air outlet is used. The shelves are shorter to avoid interference with the air curtain and there would be an unacceptable gap between the front edge of the shelves 3a-3e and the aerofoils 6a-6e if these were maintained in the same position as in FIG. 1.
(9) FIG. 2 shows a first solution to the problem. Only the top portion of the refrigerator is shown. In FIG. 2, the air outlet 7 is partially occluded by a blanking plate 8 lying in a horizontal orientation. The blanking plate 8 may be a simple sheet of metal or plastic that extends across the full width of the air outlet 7. The blanking plate 8 occludes a region of the air outlet 7 that is distal from the interior space 2. The region of the air outlet 7 that is proximal to the interior space 7 is left open. In other words, it is in fluid communication with the interior space 2 so that the air curtain can flow through the proximal region.
(10) A shelf 9, which does not project so as to interfere with the air curtain, has an aerofoil 10 affixed to its front edge by way of brackets (not shown). The aerofoil 10 is aligned with an edge 11 of the blanking plate 8 that is closest to the interior space 2. Thus, as with the situation in FIG. 1, the aerofoil 10 is aligned with the outer edge of the air curtain.
(11) A cellular matrix 12 of channels is provided in the air outlet 7 such that the air must pass through the channels to form the air curtain. This can be used to direct the air curtain in the desired direction (in this case, vertically) and to control the air velocity. In this case, the size of the channels is chosen to keep the air velocity in the air curtain as close as possible to and/or lower than an initial velocity of the air curtain. The initial velocity of the air curtain is measured with an anemometer prior to modification of the refrigerator by fitting the blanking plate. In practice, the cellular matrix 12 is chosen from a range of available matrices to restore the air velocity as closely as can be achieved to its initial value. The chosen matrix will have channels that are wider than those of any originally fitted cellular matrix, which of course would be removed during the modification of the refrigerator. Without the cellular matrix 12, the air velocity would increase as a result of the air outlet being effectively reduced in depth by the fitting of the blanking plate 8. The cellular matrix is supported on flanges 13a and 13b. The presence of the cellular matrix 12 allows the blanking plate 8 to be fitted by screwing it to the cellular matrix 12.
(12) In FIG. 3, the blanking plate 8 is fitted to the region of the air outlet 7 that is proximal to the interior space 2. The region of the air outlet 7 distal from the interior space 2 is left open. As can be seen, the arrangement of air outlet 7, blanking plate 8 and cellular matrix 12 is otherwise identical to that shown in FIG. 2. This arrangement allows a deeper shelf 14 to be fitted, the outer edge of which lies underneath the blanking plate 8. The aerofoil 10 is aligned with the outer edge of the air outlet 7 without leaving an unacceptably large gap between the shelf 14 and the aerofoil 10.
(13) FIG. 4 shows another solution, in which a vertically oriented blanking plate 15 occludes the region of the air outlet 7 distal from the interior space 2. The blanking plate 15 may be L-shaped, one part of the L-shaped plate being fixed (for example, by screws) to the top wall of the refrigerator above air outlet 7, thereby leaving the other part of the L-shaped plate depending vertically as is shown in FIG. 4. The same shelf 9 as shown in FIG. 2 is used in FIG. 4 and the aerofoil 10 is in the same position, aligned with the outer edge of the air curtain. The cellular matrix 16 that is used is narrower than in FIGS. 2 and 3. It is supported by flange 13a and by a flange 17 on the blanking plate 15. A minor variation is shown in FIG. 5, in which the flange 17 extends either side of the vertical part of blanking plate 15 to meet the front wall of the refrigerator 1. This allows a more rigid attachment of the blanking plate 15.
