WO2008051226A1

WO2008051226A1 - Secondary airflow distribution for a display case

Info

Publication number: WO2008051226A1
Application number: PCT/US2006/041708
Authority: WO
Inventors: Kwok Kwong Fung
Original assignee: Carrier Corporation
Priority date: 2006-10-26
Filing date: 2006-10-26
Publication date: 2008-05-02
Also published as: CA2659049A1; US20090205351A1

Abstract

A display case cools and displays products. A first fan system circulates cool air through the display case. The cool air is directed downwardly along a front of the display case to form a primary air curtain. A second fan system circulates ambient air to generate a secondary air curtain. The secondary air curtain is located between the primary air curtain and the outside environment, trapping the primary air curtain near an interior display volume of the display case. Each end of the second fan system is several inches shorter than the display case to allow for case to case attachment. The second fan system includes a louver near each of the side walls and a front of the second fan system. Each louver includes a plurality of slanted panels. The louvers direct the ambient air towards the side walls of the display case to improve the secondary discharge air velocity in a front corner area of the display case.

Description

SECONDARY AIRFLOW DISTRIBUTION FOR A DISPLAY CASE

BACKGROUND OF THE INVENTION

The present invention relates generally to a display case including a fan system having deflectors that direct ambient air towards side walls of the display case to improve the discharge air velocity of the ambient air in a front corner area of the display case.

Refrigerated food and beverage display cases (or merchandisers) are commonly used in grocery stores or supermarkets to cool refrigerated products and present the products to customers in an appealing manner. A first fan system generates a first air curtain that cools the products in the display case. A second fan system generates a second air curtain that reduces the entrapment of ambient air in the display case.

Several display cases can be attached side by side. The second fan system is several inches shorter than the display case at each side to allow for case to case attachment. A drawback to prior display cases is that the flow of ambient air is restricted towards the side walls of the display case, reducing the supply and velocity of ambient air at both ends of the display case. The ratio of the primary discharge air velocity to the secondary discharge air velocity ratio should be maintained in an acceptable range along an entire length of the display case or weak spots can occur where the velocity ratio is not correct and local infiltration can occur. If the desired ratio is not maintained, condensation can form at top front corners of the interior display volume of the display case. For example, the secondary discharge air velocity of the ambient air directed towards the side walls of the display case could be 40 to 50% of the desired secondary discharge air velocity.

Hence, there is need in the art for a display case including a fan system having deflectors that direct ambient air towards side walls of the display case to improve the discharge air velocity of the ambient air in a front corner area of the display case and that overcomes the drawbacks and shortcomings of the prior art. SUMMARY OF THE INVENTION

A display case or merchandiser cools and displays products. A first fan system located at a bottom of the display case circulates cool air through the display case. An evaporator coil cools the air, and the cooled air is directed upwardly through a rear duct along a rear of the display case. After traveling through an upper conduit at a top of the display case, the air is directly through a primary discharge grill and downwardly over a front of the display case to form a primary air curtain.

A second fan system circulates ambient air to generate a secondary air curtain. A fan draws ambient air into the secondary air system. The air flows through a space and is then directed through a conduit. The ambient air is directed through a secondary discharge grill and downwardly to form the secondary air curtain. The secondary air curtain is located between the primary air curtain and the outside environment, trapping the primary air curtain near an interior display volume of the display case. Each end of the second fan system is several inches shorter than the display case to allow for case to case attachment. The second fan system includes a louver near each of the side walls and a front of the second fan system. Each louver includes a plurality of slanted panels. The louvers direct the ambient air towards the side walls of the display case to improve the secondary discharge air velocity in a front corner area of the display case.

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 drawings that accompany the detailed description can be briefly described as follows:

Figure 1 schematically illustrates a side view of a display case of the present invention; Figure 2 schematically illustrates a side view of a fan system of the display case;

Figure 3 schematically illustrates a front view of the display case; Figure 4 schematically illustrates two display cases attached together; Figure 5 schematically illustrates an upper view of a louver; and

Figure 6 schematically illustrates a side view of the louver.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Figure 1 illustrates a supermarket display case 10 or merchandiser. The display case 10 cools or refrigerates products 12 and presents the products 12 to customers in an appealing manner. The products 12 can be produce, dairy products, meat products, or any other refrigerated product. The display case 10 includes shelves 36 that hold the products 12.

The display case 10 includes a first fan system 14 that circulates cool air through the display case 10 to cool the products 12 to a desired temperature. The display case 10 includes a fan blade 84 and a fan motor 86 located in a lower section 16 of the display case 10 that draws air through a return grille 18. The air is forced through an evaporator coil 20 (part of a refrigeration system including a compressor, not shown) that cools the air to a desired temperature. The cooled air flows upwardly through a rear duct 22. Part of the air moving up the rear duct 22 also diffuses into an interior display volume 30 of the display case 10 through holes 38 in a rear duct panel 40 to help refrigerate the products 12.

The air then flows to a front 82 of the display case 10 through an upper conduit 24. The air flows through a perforated plate 34 and is discharged downwardly and vertically towards a floor 32 through a primary discharge grille 26 (such as a honeycomb) to form a primary air curtain 28. The primary air curtain 28 cools the products 12 in the display case 10, separating the interior display volume 30 from the ambient air external to the display case 10. The air then flows through the return grille 18, completing the air circulation cycle. As further shown in Figure 2, the display case 10 further includes a second fan system 42 located above a top 50 of the display case 10 that draws in ambient air and generates a secondary air curtain 48 that is discharged downwardly and vertically. A panel 68 separates the primary air curtain 28 from the secondary air curtain 48 in the second fan system 42. The temperature of the ambient air is greater than the temperature of the air cooled by the evaporator coil 20. The secondary air curtain 48 flows next to the primary air curtain 28 at a desired velocity and/or at a different angle than the primary air curtain 28 to provide an optimized combined airflow and to improve the overall efficiency of the air curtain system of the display case 10. In one example, the primary air curtain 28 and the secondary air curtain 48 are separated by an angle of approximately 15 to 35°. The secondary air curtain 48 is located between the primary air curtain 28 and the outside environment, trapping the primary air curtain 28 near the interior display volume 30 of the display case 10. The secondary air curtain 48 reduces the entrapment of the higher temperature and higher humidity ambient air into the display case 10, reducing the load requirement because there is less heat and mass transfer into the display case 10. A fan motor 44 and a fan blade 46 draw ambient air into the second fan system

42 through an opening 52. The ambient air travels through a space 54 along a path A above a panel 58. The air then flows though a conduit 56 along a path B below the panel 58 towards the front 82 of the display case 10. The air then flows through an opening 60 and into a space 62 along a path C. The air then travels through a perforated plate 64 and then discharges through a secondary discharge grille 66 (such as a honeycomb), forming the secondary air curtain 48.

Figure 3 shows a front view of the display case 10 and the second fan system 42. The air drawn into the display case 10 through the opening 52 flows through the space 54 in a direction substantially into the page along the path A. In one example, the air flows entirely along a length Y of the second fan system 42. The air then flows through the conduit 56 in a direction substantially out of the page along the path B. In one example, the air flows along the entire length Y of the second fan system 42. Finally, the air flows downwardly and vertically along the path C.

The display case 10 has a length X extending between side walls 70. The second fan system 42 has the length Y that extends between side walls 72. The length Y of the second fan system 42 is shorter than the length X of the display case 10 by a length 2Z. That is, each side wall 72 of the second fan system 42 is spaced apart from each side wall 70 of the display case 10 by a length Z. In one example, the length X is 144 inches, the length Y is 136 inches, and the length Z is 4 inches. That is, each end wall 72 of the second fan system 42 is recessed from one of the side walls 70 of the display case 10 by 4 inches. Therefore, the air flowing along paths A, B and C is not directed towards the side walls 70 of the display case 10.

As shown in Figure 4, two or more display cases 10 can be attached to form a display case lineup, allowing for a continuous product display that can be longer than the length X of the display case 10. There is no partition between the individual display cases 10, and therefore products 12 off similar usage or temperature can be displayed. The length Y of the second fan system 42 is shorter than the length X of the display case 10 to provide an access area 74 that allows display cases 10 to be connected. In one example, the display cases 10 are attached with a bolt 88 that passes through a bracket 92 in the side wall 70 of each the display case 10. In one example, the access area 74 is located at the top front area of the display case 10. The display cases 10 are attached at the top front area and in other areas to form a sealed connection. For example, the other areas can be a top back area and a bottom of the display cases 10.

Returning to Figure 3, the panel 58 includes a deflector near each side wall 72 of the second fan system 42. In one example, the deflector is a louver 76. That is, each display case 10 includes two louvers 76. Each louver 76 is near a front 90 of the second fan system 42 and only extends partially along a depth W of the second fan system 42.

Each louver 76 allows some of the pressurized air in the space 54 to be directed toward one of the side walls 70 of the display case 10 downwardly and vertically along a path D, improving airflow at the side walls 70 of the display case 10. The louvers 76 direct a small portion of the ambient air of the second fan system 42 into a front corner area of the secondary discharge grille 66 and towards the side walls 70 of the display case 10. The airflow along the path D is directed generally under the access area 74. The secondary discharge air velocity at the side walls 70 of the display case 10 can be increased to a desired air velocity, resulting in a consistent primary air discharge velocity to secondary discharge air velocity ratio throughout the length X of the display case 10. Weak spots in the secondary air curtain 48 can be eliminated that could allow outside air to migrate into the display case 10 and form condensation inside a front comer area of the interior display volume 30 of the display case 10.

Figures 5 and 6 illustrate the louver 76. Each louver 76 includes a plurality of slanted panels 78 and openings 80 defined between each of the slanted panels 78. The slanted panels 78 are angled so that the ambient air is directed towards the side walls 70 of the display case 10. In one example, the louvers 76 are stamped in the panel 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.

Claims

CLAIMSWhat is claimed is:

1. A refrigerated case comprising: a display area having an interior compartment and side walls; a first fan system that directs air along a front of the refrigerated case to form a first air curtain; and a second fan system that directs ambient air along the front of the refrigerated case to form a second air curtain, wherein the first air curtain is between the interior compartment and the second air curtain, and the second fan system includes at least one deflector that directs at least some of the ambient air towards one of the side walls of the refrigerated case.

2. The refrigerated case as recited in claim 1 wherein the first fan system includes a first fan and a first motor located in a lower portion of the refrigerated case and an evaporator coil to cool the air.

3. The refrigerated case as recited in claim 1 wherein the air is directed downwardly to form the first air curtain.

4. The refrigerated case as recited in claim 1 wherein the second fan system is located above the interior compartment.

5. The refrigerated case as recited in claim 1 wherein the second fan system includes a second fan and a second motor, wherein the second fan draws the ambient air into the second fan system.

6. The refrigerated case as recited in claim 1 further including a panel, wherein the ambient air flows under the panel and is directed downwardly to form the second air curtain.

7. The refrigerated case as recited in claim 6 wherein the panel includes the at least one deflector.

8. The refrigerated case as recited in claim 6 wherein the at least one deflector includes two deflectors and the panel includes the two deflectors, wherein each of the two deflectors is located near the one of the side walls.

9. The refrigerated case as recited in claim 1 wherein the at least one deflector includes a plurality of slanted panels each separated by a slot that allow the ambient air to flow through the at least one deflector and towards the one of the side walls.

10. The refrigerated case as recited in claim 1 wherein the display area has a display area length and the second fan system has a fan length, and the display area length is greater than the fan length.

11. The refrigerated case as recited in claim 1 wherein the at least one deflector is located near the front of the refrigerated case.

12. The refrigerated case as recited in claim 1 wherein the at least one deflector extends only partially along a depth of the second fan system.

13. The refrigerated case as recited in claim 1 wherein the at least one deflector is at least one louver.

14. A refrigerated case comprising: a display area having an interior compartment and side walls; a first fan system that directs air along a front of the case to form a first air curtain, wherein the first fan system includes a first fan and a first motor located in a lower portion of the refrigerated case and an evaporator coil to cool the air; and a second fan system that directs ambient air along the front of the case to form a second air curtain, wherein the second fan system includes a second fan and a second motor, wherein the second fan draws the ambient air into the second fan system, the first air curtain is between the interior compartment and the second air curtain, and the second fan system includes at least one deflector that directs at least some of the ambient air towards one of the side walls of the refrigerated case.

15. The refrigerated case as recited in claim 14 further including a panel, wherein the air is directed downwardly to form the first air curtain and the ambient air flows under the panel and is directed downwardly to form the second air curtain.

16. The refrigerated case as recited in claim 14 wherein the at least one deflector includes two deflectors and the panel includes the two deflectors, wherein each of the two deflectors is located near the one of the side walls.

17. The refrigerated case as recited in claim 14 wherein the at least one deflector includes a plurality of slanted panels each separated by a slot that allow the ambient air to flow through the at least one deflector and towards the one of the side walls.

18. The refrigerated case as recited in claim 14 wherein the at least one deflector is at least one louver.

19. A method of cooling a refrigerated case, the method comprising the steps of: directing air along a front of the refrigerated case to form a first air curtain; directing ambient air along the front of the refrigerated case to form a second air curtain, wherein the first air curtain is between an interior compartment and the second air curtain; and directing at least some of the ambient air towards at least one side wall of the refrigerated case.