Note: Descriptions are shown in the official language in which they were submitted.
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AIRFLOW STABILIZER FOR LOWER FRONT OF A REAR LOADED
REFRIGERATED DISPLAY CASE
BACKGROUND OF THE INVENTION
The present invention relates generally to a rear loaded refrigerated display
case
including a deflector that prevents a discharge airflow from flowing upwardly
to heat
product on lower shelves in the case.
Refrigerated display cases are commonly used in grocery stores to cool
groceries
and other refrigerated products. Shoppers can access the refrigerated products
from a
front of the display case without the obstruction of a door. A walk-in cooler
adjacent to a
rear of the display case keeps the refrigerated products fresh prior to being
stocked in the
case. The refrigerated items can be re-stocked in the display case without
interrupting
customer traffic. A curtain separates a rear of the display case from the
cooler. The
temperature in the display case is generally between 26 F and 43 F.
In the prior art display case, cooled air flows along a front air curtain to
cool the
products. Air is drawn through a return grille by a fan located at the front
bottom of the
display case. The air is then directed through a discharge grille and under
shelves in the
case to return to the cooler.
A drawback to prior display cases is that some of the air drawn by the fan
diffuses
upwardly instead of being returned to the cooler. The stray air can flow
towards the
product on the lower shelves or hit the shelves and the wheels (if any) and
bounces
upwardly toward the products on the lower shelves. The stray air can increase
the
temperature of the products on display in the display case. Further, the
suction force of
the fan draws some of the stray air back into the return grille for
recirculation back
through the fan, increasing the power requirement of the fan, wasting power
and
increasing costs.
When the warm return air, which is approximately low 40s F to the mid 50s F,
hits the product on the lower shelves, the temperature of the product can
stabilize at mid
40s F to 50 F. As a result, the product on the lower shelves can be exposed to
warmer
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air. It is therefore difficult to maintain the product on the lower shelves at
lower
temperatures.
Hence, there is need in the art for a rear loaded refrigerated display case
including
a deflector that prevents a discharge airflow from flowing upwardly to heat
product on
lower shelves in the case and that overcomes the drawbacks and shortcomings of
the prior
art.
SUMMARY OF THE INVENTION
A refrigerated display case cools products stocked on shelves. A curtain
separates
the display case from a cooler. Air in the cooler is drawn into a first coil
and cooled.
Some of the cool air is drawn into a channel in a top portion of the display
case by a first
fan system. The cool air is then further cooled by a second coil.
Some of the cooled air leaving the second coil is discharged through a
discharge
grille in the top portion of the display case. The air flows along the front
of the display
case to define a front air curtain. A second fan system at the bottom of the
display case
draws the air from the front air curtain through a return grill. The second
fan system
blows the air through a grille, under the shelves and into the cooler.
Some of the cooled air leaving the second coil flows through a channel under
the
second coil and is directed along the curtain to define a rear air curtain.
Some of the air
in the rear air curtain is directed substantially perpendicularly towards the
front of the
display case and flows over and cools the product on the shelves. The second
fan system
draws the air through the grille, under the shelves and into the cooler.
The display case further includes a lower case front that houses the second
fan
system. A deflector is installed between the lower case front and the shelves.
The
deflector provides a barrier to prevent stray air that flows from the grille
from diffusing
upwardly and warming the product on the lower shelves. The deflector also
stops the
stray air from recirculating through the return grill and from being drawn
back through
the second fan system.
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These and other features of the present invention will be best understood from
the
following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The various features and advantages of the invention will become apparent to
those skilled in the art from the following detailed description of the
currently preferred
embodiment. The drawing that accompany the detailed description can be briefly
described as follows:
Figure 1 schematically illustrates a refrigerated display case of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Figure 1 illustrates a refrigerated display case 10 of the present invention.
The
display case 10 is a rear load display case 10 that can be used in a grocery
store or a
supeimarket. A cart 12 including shelves 14 is received in an interior
compartment 11 of
the display case 10. Alternately, the shelves 14 are secured in the display
case 10 and are
not part of a cart. Alternately, the display case 10 includes a base platform
onto which
boxes or other products are stocked. Groceries or other refrigerated products
16 are
stocked on the shelves 14 of the cart 12. The products 16 can be produce,
dairy products,
meat products, or any refrigerated products. The temperature in the display
case 10 is
approximately between 26 F and 43 F. A walk-in cooler 18 is located behind the
display case 10. The cooler 18 keeps the products 16 fresh before being
stocked in the
display case 10. A moveable plastic or vinyl curtain or door 20 separates the
cooler 18
from the display case 10.
The cart 12 is located in the cooler 18 when stocking the product 16 onto the
shelves 14. The curtain or door 20 is opened, and the cart 12 is then slide on
wheels 22
over the floor 24 towards a front 27 of the display case 10 until the front
wheels 22 hit a
cart stop 26 bolted to the floor 24. The cart stop 26 has a substantially C-
channel shape
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and can be made of iron. The curtain or door 20 is then closed along a rear 28
of the
display case 10 to provide a barrier between the cart 12 and the cooler 18. A
customer
can then access the products 16 from the front 27 of the display case 10 while
shopping.
Air 30 in the cooler 18 is drawn into a first coi132 and cooled to form cool
air 34.
The first coil 32 is part of a refrigeration system that includes a compressor
(not shown).
Some of the cool air 34 is discharged into the cooler 18.
Some of the cool air 34 is drawn into a channel 36 in the top portion 38 of
the
display case 10 by a first fan system 40. In one example, the first fan system
40 includes
three to six fans. The first fan system 40 is located at both the rear 28 and
the top portion
38 of the display case 10. The cool air 34 is then further cooled by a second
coil 42 to
form cooled air 44. The cooled air 44 has a temperature of approximately 27 F
to 32 F.
Some of the cooled air 44 leaving the second coil 42 is discharged through a
discharge grille 46 at the top portion 38 of the display case 10. The air
flows along the
front 27 of the display case 10 to form a front air curtain 48. In one
example, the
discharge grille 46 is a honeycomb. The air in the front air curtain 48 is
directed
substantially downwardly and vertically towards the floor 24.
A second fan system 50 draws the air from the front air curtain 48 through a
return
grille 52. In one example, the second fan system 50 includes three to six
fans. The return
grille 52 is a metal perforated piece. The air flowing through the return
grille 52 is
generally approximately 40s F to the 50s F, depending on the design of the
display case
10, the air curtain, and the store conditions. The second fan system 50 is
located at both
the front 27 and a bottom portion 54 of the display case 10. The second fan
system 50
blows the air through a grille 56, under the cart 12 and into the cooler 18,
completing the
cycle.
Some of the cooled air 44 leaving the second coi142 flows through a channel 66
under the second coil 42 and is directed along the curtain or door 20 to form
a rear air
curtain 60. The air flowing along the rear air curtain 60 is directed
substantially
downwardly and vertically towards the floor 24. Some of the air 62 in the rear
air curtain
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60 is directed substantially perpendicularly towards the front 27 of the
display case 10 to
flow over and cool the products 16 on the shelves 14. The air 62 flowing over
the
product 16 on the shelves 14 reduces the temperature of the product 16. The
second fan
system 50 draws the air 62 through the return grille 52, under the cart 12 and
into the
cooler 18, completing the cycle. Although the rear air curtain 60 is
illustrated and
described, it is to be understood that the rear air curtain 60 is not required
in some
designs.
The display case 10 further includes a lower case front 58. The return grille
52,
the grille 56 and the second fan system 50 are all housed in or part of the
lower case front
1o 58. The lower case front 58 is typically located approximately two to
several inches away
from the cart 12 when the cart 12 is positioned in the display case 10. The
cart stop 26
structurally protects the lower case front 58 as the cart 12 is pushed
forwardly into the
display case 10. Therefore, the cart stop 26 acts as a structural barrier
between the cart
12 and the lower case front 58. When the cart 12 is located in the display
case 10, the
cart stop 26 is located between the wheels 22 of the cart 12 and the lower
case front 58.
The cart stop 26 can be a separate element from the lower case front 58.
However, the
cart stop 26 can also be a part of the lower case front 58.
Some of the air drawn through the grille 56 by the second fan system 50 tends
to
diffuse upwardly towards the lower shelves 14 of the cart 12 instead of being
drawn into
the cooler 18, heating the product 16 on the lower shelves 14. Some of the air
drawn
through the grille 56 by the second fan system 50 also tends to recirculate
and be drawn
into the return grille 52 by the second fan system 50.
A deflector 64 is installed near the grille 56 and an outlet of the second fan
system
50. The deflector 64 can be made of plastic or metal. The deflector 64 is
located between
one of the shelves 14 and the lower case front 58 (including the grille 56)
and is located
substantially over the cart stop 26. If the display case 10 includes a cart
12, the deflector
64 is located between the cart 12 and the lower case front 58. If the display
case includes
a base platform, the deflector 64 is located between the platform and the
lower case front
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58. In one example, the deflector 64 is substantially parallel to the floor 24
and
substantially horizontal. However, the deflector 64 can also be angled or
inclined with
respect to the floor 24. The deflector 64 can be an integral piece of the
lower case front
58 or can be retrofitted and added to display cases 10 that are already used
in the stores.
The deflector 64 can be optionally mounted to the display case 10 during
installation or
can be an integral part of the display case 10. Alternately, both the cart
stop 26 and the
deflector 64 can be an integral part of the lower case front 58.
The deflector 64 minimizes turbulence and provides a barrier to prevent stray
air
that flows from the grille 56 from diffusing upwardly to the lower shelves 14
of the cart
12 and warming the product 16 on the lower shelves 14. The deflector 64 also
stops the
stray air from recirculating through the return grille 52 and from being drawn
through the
second fan system 50, reducing air circulation and the power consumption of
the second
fan system 50. The deflector 64 directs the air from the grille 56 under the
cart 12 and
into the cooler 18 and prevents the air from flowing into the lower section of
the cart 12
or from re-entering the return grille 52.
The deflector 64 also prevents the stray air from affecting the air in the
front air
curtain 48 at the front 27 of the display case 10. Therefore, the air in the
front air curtain
48 follows the profile of the cart 12 more closely, allowing the air on the
inside of the
front air curtain 48 to cool the product 16 on the lower shelves 14. The air
temperature
on a side of the front air curtain 48 in the display case 10 is colder than
the air
temperature on a side of the front air curtain 48 outside the display case 10
in the store
environment (typically about 70 F to 75 F). The cold air in the front air
curtain 48 can
reach the product 16 on the lower shelves 14 without the interference of the
stray air from
the second fan system 50.
The deflector 64 also prevents the stray air from the grille 56 from
pressurizing
the air around the lower shelves 14 that can slow or stop the airflow from the
rear air
curtain 60 from diffusing to the lower shelves 14. The deflector 64 allows the
air from
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the rear air curtain 60 to diffuse into the cart 12 to better maintain a
desired temperature
of the product 16 on the lower shelves 14.
By employing the deflector 64, the temperature of the product 16 on the lower
shelves 14 of the cart 12 can be decreased by approximately 2 F to 10 F,
depending on
the type of merchandising application, the air curtain and the design of the
lower case
front 58.
The foregoing description is only exemplary of the principles of the
invention.
Many modifications and variations of the present invention are possible in
light of the
above teachings. The preferred embodiments of this invention have been
disclosed,
1o however, so that one of ordinary skill in the art would recognize that
certain
modifications would come within the scope of this invention. It is, therefore,
to be
understood that within the scope of the appended claims, the invention may be
practiced
otherwise than as specifically described. For that reason the following claims
should be
studied to determine the true scope and content of this invention.
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