Multi-band air curtain separation barrier

1. A method for establishing a separation barrier at an interface between a first environment having a fluid at a first condition and a second environment having a fluid at a second condition comprising:

directing a first stream of fluid drawn from the first environment across the interface between said first environment and said second environment along a first path generally parallel to the interface, thereby establishing a primary fluid curtain along the interface;

directing a second stream of fluid drawn from the second environment across the interface between said first environment and said second environment along a second path at an angle of divergence with the first path in a direction towards said second environment, thereby establishing a tertiary fluid curtain outwardly of said primary fluid curtain, the angle of divergence between said second path and said first path ranging from about 10 degrees to about 70 degrees; and

directing a third stream of a fluid along a third path between said first path and said second path at a first interior angle with said first path ranging from about 5 degrees to about 35 degrees and at a second interior angle with said second path ranging from about 5 degrees to about 35 degrees, thereby establishing a secondary fluid curtain intermediate said primary fluid curtain and said tertiary fluid curtain.

2. A method for establishing a separation barrier between a first environment and a second environment as recited in claim 1 wherein said second interior angle ranges from 15 degrees to 35 degrees.

3. A method for establishing a separation barrier between a first environment and a second environment as recited in claim 1 further comprising maintaining said third stream of fluid at a temperature in the range between a first relatively cooler temperature of the first fluid stream and a second relatively warmer temperature of the second fluid stream.

4. A method for establishing a separation barrier between a first environment and a second environment as recited in claim 1 further comprising:

directing the first fluid stream along the first path at a first discharge velocity;

directing the second fluid stream along the second path at a second discharge velocity greater than said first discharge velocity; and

directing the third fluid stream along the third path at a third discharge velocity greater than the first discharge velocity and less than the second discharge velocity.

5. A method for establishing a separation barrier between a first environment and a second environment as recited in claim 4 further comprising maintaining the ratio of the second discharge velocity to the first discharge velocity at a magnitude of at least about 1.4.

6. A method for establishing a separation barrier between a first environment and a second environment as recited in claim 5 further comprising maintaining the ratio of the second discharge velocity to the first discharge velocity within the range of from about 1.4 to about 2.4.

7. A method for establishing a separation barrier between a first environment and a second environment as recited in claim 5 further comprising maintaining the ratio of the third discharge velocity to the first discharge velocity within the range of from about 1.2 to about 2.0.

8. A method for establishing a separation barrier between a first environment and a second environment as recited in claim 4 further comprising maintaining the ratio of the third discharge velocity to the second discharge velocity at a magnitude ranging from greater than 1.0 to about 1.25.

9. A refrigerated merchandiser comprising:

a display case having an exterior and an interior, said interior defining a refrigerated product display region having an open front interfacing with an ambient environment;

a first discharge outlet associated with said display case for directing a first stream of air at a relatively cooler temperature generally parallely across the open front of the merchandiser along a first path;

a second discharge outlet associated with said display case for directing a second stream of air a relatively warmer temperature generally outwardly across the open of the merchandiser along a second path at a divergent angle with respect to the first path ranging from about 10 degrees to about 70 degrees; and

a third discharge outlet associated with said display case for directing a third air stream generally outwardly across the open front of the merchandiser along a third path, said third air outlet positioned between said first discharge outlet and said second discharge outlet, said third path diverging from said first path at an interior angle ranging from about 5 degrees to about 35 degrees and diverging from said second path at an interior angle ranging from about 5 degrees to about 35 degrees.

10. A refrigerated merchandiser as recited in claim 9 wherein said second interior angle ranges from 15 degrees to 35 degrees.

11. A refrigerated merchandiser as recited in claim 9 wherein said third stream of fluid has a temperature in the range between the relatively cooler temperature of the first air stream and the relatively warmer temperature of the second air stream.

12. A method for operating a refrigerated merchandiser having a display case defining a refrigerated product display region having an open front interfacing with an ambient environment, comprising:

directing a first stream of refrigerated air drawn from the product display region along a first path across the open front of the display case, thereby establishing a primary air curtain across the open front of the display case;

directing a second stream of ambient air drawn from exteriorly of the refrigerated merchandiser across the open front of the display case along a second path at an angle of divergence with the first path in a direction away from the open front of the display case, thereby establishing a tertiary air curtain outwardly of said primary air curtain, the angle of divergence between said second path and said first path ranging from about 10 degrees to about 70 degrees; and directing a third stream of air along a third path between said first path and said second path at a first interior angle with said first path ranging from about 5 degrees to about 35 degrees and at a second interior angle with said second path ranging from about 5 degrees to about 35 degrees, thereby establishing a secondary air curtain intermediate said primary air curtain and said secondary air curtain.

13. A method for operating a refrigerated merchandiser as recited in claim 12 further comprising:

discharging the first air stream from said first discharge outlet along the first path at a first discharge velocity;

discharging the second air stream from the second discharge outlet along the second path at a second discharge velocity greater than said first discharge velocity; and

discharging the third air stream from the third discharge outlet along the third path at a third discharge velocity greater than the first discharge velocity and less than the second discharge velocity.

14. A refrigerated merchandiser as recited in claim 13 wherein the ratio of the second discharge velocity to the first discharge velocity has a magnitude of at least about 1.4.

15. A refrigerated merchandiser as recited in claim 13 wherein the ratio of the second discharge velocity to the first discharge velocity has a magnitude within the range of from about 1.4 to about 2.4.

16. A refrigerated merchandiser as recited in claim 15 wherein the ratio of the third discharge velocity to the first discharge velocity has a magnitude within the range of from about 1.2 to about 2.0.

17. A refrigerated merchandiser as recited in claim 15 wherein the ratio of the third discharge velocity to the second discharge velocity has a magnitude ranging from greater than 1.0 to about 1.25.