AIR COOLED DISPLAY CASE SHELF

VITRINE REFROIDIE PAR DE L'AIR

English Abstract

A refrigerated display case is provided that includes a display chamber for displaying product. The display chamber includes a product tray for supporting the product. A cooling chamber is arranged beneath the product and is in communication with a surface of the product tray. The cooling chamber is sealed from the display chamber, in one example, and includes a cooling coil. A fan is in communication with the cooling chamber and cooling coil. The fan circulates a cooling flow through the cooling coil. The cooling flow moves across the surface and absorbs` heat from the product tray by convection. The cooled product tray removes heat from the product by conduction.

French Abstract

L'invention concerne une vitrine réfrigérée qui comprend une chambre de présentation pour présenter un produit. La chambre de présentation comprend un support de produit pour supporter le produit. Une chambre de refroidissement est agencée sous le produit, et est en communication avec une surface du support de produit. La chambre de refroidissement est étanchéifiée par rapport à la chambre de présentation, selon un premier exemple, et comprend une bobine de refroidissement. Un ventilateur est en communication avec la chambre de refroidissement et la bobine de refroidissement. Le ventilateur fait circuler un flux de refroidissement à travers la bobine de refroidissement. Le flux de refroidissement se déplace à travers la surface et absorbe de la chaleur à partir du support de produit par convection. Le support de produit refroidi supprime de la chaleur provenant du produit par conduction.

Claims

CLAIMS
1. A refrigerated display case comprising:
a display chamber having a product tray for supporting product;
a cooling chamber in communication with the product tray, the cooling
chamber including a cooling coil; and
a fan in communication with the cooling chamber and cooling coil for
generating an air flow across a surface of the product tray to remove heat
therefrom.
2. The refrigerated display case according to claim 1, wherein the fan
generates
a horizontal cooling flow across the product tray, the cooling chamber
arranged
beneath the product tray.
3. The refrigerated display case according to claim 2, comprising a baffle
arranged in the cooling chamber, the baffle directing the cooling flow across
the
surface of the product tray.
4. The refrigerated display case according to claim 3, wherein the fan blows
the
cooling flow generally parallel to the baffle.
5. The refrigerated display case according to claim 3, wherein the fan blows
the
cooling flow generally parallel to the product tray.
6. The refrigerated display case according to claim 5, wherein the fan is
arranged between first and second coils, first and second baffles associated
with
each of said first and second coils, first and second cooling flows generated
from the
fan in opposing directions respectively through first and second coils and
returning
to said fan.

7. The refrigerated display case according to claim 1, wherein the product
tray
is sealed relative to the display chamber.
8. The refrigerated display case according to claim 1, wherein the cooling
flow
generates convection cooling of the product tray.
9. The refrigerated display case according to claim 8, wherein the convection
cooling generates conduction cooling of product on the product tray.
10. The refrigerated display case according to claim 1, comprising a gravity
coil
arranged in the display chamber, the gravity coil generating radiation cooling
providing a buoyancy circulation within the display chamber.
11. The refrigerated display case according to claim 1, comprising a
refrigerant
system that includes the cooling coil and a gravity coil arranged within the
display
chamber, a refrigerant from the cooling coil and gravity coil flowing to a
compressor
arranged upstream from a heat exchanger, the refrigerant from the heat
exchanger
flowing to an expansion device before being received by the cooling coil.
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12. A method of refrigerating a product comprising the steps of:
supporting a product within a display chamber using a product tray;
generating a convection cooling on a surface of the product tray separated
from the product; and
cooling the product with conduction cooling from the product tray.
13. The method according to claim 12, comprising the step of generating a
cooling flow in a cooling chamber arranged beneath the product tray.
14. The method according to claim 13, comprising blowing the cooling flow
across a cooling coil.
15. The display case according to claim 1, wherein the cooling coil includes
fins.
16. The display case according to claim 1, wherein the display chamber
includes
a display window providing visual access to the product within the display
chamber.
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Description

CA 02688177 2009-11-23
WO 2008/150297 PCT/US2007/070705
AIR COOLED DISPLAY CASE SHELF
BACKGROUND OF THE INVENTION
This application relates to a refrigerated display case for refrigerating and
displaying food products.
Refrigerated display cases are used to refrigerate and display products such
as meat at a grocery store. The products are displayed to customers in a
display
chamber that is cooled by a gravity coil. The gravity coil cools the product
by
buoyancy circulation in which the cooled air produced by the gravity coil
moves
downward toward the product as it becomes more dense. As the cooled air
absorbs
heat from the product, the warmed air rises toward the gravity coil where it
is again
cooled. In this manner, cooled air is circulated within the display chamber
without
the use of a fan, which would undesirably dry the product.
The product is supported on a product tray. A serpentine coil is arranged in a
cooling chamber beneath the product tray. The serpentine coil and gravity coil
are
connected in series. The serpentine coil has no fins and typically extends
along the
length of the display case. The serpentine coil is not permitted to touch the
product
tray since its temperature is much colder than freezing. The serpentine coil
simply
removes any heat gain attributable to the lower portion of the display case to
prevent
heat gain in the product. The majority of the refrigerant load is associated
with the
gravity coil, which results in an unbalanced, inefficient refrigeration
system.
What is needed is a refrigerated display case that improves heat removal
from the products while balancing and reducing the overall refrigeration load
on the
refrigerant system. Furthermore, it is desired that the refrigeration system
avoid
drying the product.
SUMMARY OF THE INVENTION
A refrigerated display case is provided that includes a display chamber for
displaying product. The display chamber includes a product tray for supporting
the
product. A cooling chamber is arranged beneath the product and is in
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CA 02688177 2009-11-23
WO 2008/150297 PCT/US2007/070705
communication with a surface of the product tray. The cooling chamber is
sealed
from the display chamber, in one example, and includes a cooling coil. A fan
is in
communication with the cooling chamber and cooling coil. The fan circulates a
cooling flow through the cooling coil. The cooling flow moves across the
surface
and absorbs heat from the product tray by convection. The cooled product tray
removes heat from the product by conduction.
These and other features of the application can be best understood from the
following specification and drawings, the following of which is a brief
description.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic, cross-sectional view of an example refrigerated
display case.
Figure 2 is a schematic view of a refrigerant system used to cool the display
case shown in Figure 1.
Figure 3 is a schematic, cross-sectional view of another example refrigerated
display case.
Figure 4 is a cross-sectional view of a portion of a cooling coil for use in
the
refrigerated display case.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A refrigerated display case 10 is shown in Figures 1 and 3. The display case
10 includes a display chamber 12 used for supporting products 14, such as
meat.
The display chamber 12 includes a display window 16 through which customers
view the products 14. The display chamber 12 is accessible through access
panels
18 opposite the display window 16. Typically, an air curtain device 22 that
includes
a fan 24 blows an air curtain A across the display window 16 to minimize the
heat
transfer to the display chamber 12 through the display window 16.
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An example refrigerant system 26 is schematically shown in Figure 2. The
refrigerant system 26 includes a gravity coil 36 (also shown in Figures 1 and
3)
arranged in the display window 16. The gravity coil 36 cools the products 14
by
radiation thereby generating a buoyancy circulation B, which is shown in
Figure 3.
As the air display chamber 12 cools and becomes more dense, it flows to the
bottom
of the display chamber 12 where it removes heat from the products 14. As the
cooled air absorbs heat, it rises to the gravity coi136 where it is again
cooled. In this
manner, the products 14 are cooled without the use of a fan, which would
undesirably dry the products 14.
Returning to Figure 2, the refrigerant system 26 includes a compressor 28
that receives the refrigerant from the gravity coil 36. The compressed
refrigerant
flows to a heat exchanger 30 from which heat is rejected to an outside
environment.
Refrigerant flows from the heat exchanger 30 to an expansion device 32, for
example, that expands thereby producing cooled refrigerant. The expanded
refrigerant flows to a cooling coi146 before flowing to the gravity coi136.
Typically the compressor 28 and heat exchanger 30 are located outside the
refrigerated display case 10, and the expansion device 32, cooling coil 46 and
gravity coil 36 are located within the display case 10. However, it should be
understood that the components of the refrigerant system 26 can be located in
any
suitable location and manner. Moreover, one or more temperature sensors may be
used to communicate temperature information from various locations within the
display case 10 to provide a feedback system and accurately refrigerate the
display
case 10.
Returning to Figure 1, a cooling chamber 38 is provided beneath the display
chamber 12 and is supported by a base 20. The products 14 are supported on a
product tray 40 that separates the display chamber 12 and cooling chamber 38.
In
one example, the product tray 40 seals the cooling chamber 38 to prevent
undesired
air flow from entering the display chamber 12 from the cooling chamber 30,
which
would undesirably dry the products 14.
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CA 02688177 2009-11-23
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Typically, a foam barrier 42 is used at the bottom of the cooling chamber 38
and is supported by the base 20 to minimize heat transfer from the outside
environment into the cooling chamber 38.
In the example, a fan 44 is utilized to generate a cooling flow F within in
the
cooling chamber 38. The cooling flow F cools the product tray 40 by
convection,
which in turn cools the products 14 by conduction. In this manner, the cooling
coil
46 operates to provide significant cooling to the products 14 instead of
simply acting
as a heat sink to prevent heat transfer to the products 14 from the bottom of
the
display case 10, as in the prior art.
In one example, the cooling coils 46 include fins 48, which is shown in
Figure 4. The fins 48 increase the heat transfer to the cooling coils 46 from
the
cooling flow F as it picks up heat from the products 14 through the product
tray 40.
A baffle 50 is used in the example shown in Figure 1 to guide the cooling flow
F
horizontally along a lower surface of the product tray 40 (generally parallel)
to
maximize convection cooling to the product tray 40.
Another example arrangement is shown in Figure 3. In the example shown,
the fan 44 is arranged between coils 46. A baffle 50 is associated with each
coi146.
The cooling flow F moves laterally outward from the fan 44 to the front and
rear of
the cooling chamber 38 before returning through the respective coils 46. The
coils
46 shown in Figure 3 may be parallel, lateral lengths of the same coil, for
example.
Although example embodiments have been disclosed, a worker of ordinary
skill in this art would recognize that certain modifications would come within
the
scope of the claims. For that reason, the following claims should be studied
to
determine their true scope and content.
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Representative Drawing