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 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.
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.
These and other features of the present invention will be best understood from the following specification and 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:
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 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 coil 32 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 coil 42 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 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 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 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 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, 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.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US05/44177 | 12/7/2005 | WO | 00 | 4/23/2008 |