Cooling apparatus and method for cooling objects from a coating device

1. A cooling apparatus for cooling objects from a coating device, comprising:

a housing enclosing a cooling zone, said cooling zone having an entrance region communicating with an exit region;

a transport device extending though said housing for transporting workpieces along a transport direction through said entrance region, through said cooling zone and through said exit region;

a heat exchanger arranged within said housing, said heat exchanger comprising an entry and an exit through which a first fluid flow is guided, and further comprising pipes for guiding a second fluid flow therethrough and for transferring heat between said first and second fluid flows;

wherein said exit of said heat exchanger communicates with said cooling zone for supplying cooled air thereto; and

wherein said entrance region of said cooling zone is connected with a warm air conducting duct leading to said entry of said heat exchanger for guiding warm air from said cooling zone through said heat exchanger and for recirculating air received from said cooling zone back into said cooling zone after transferring heat to said second fluid flow.

2. The cooling apparatus of claim 1 , in which air supplied to said heat exchanger from said cooling zone has an inlet temperature of between 40° C. and 250° C.

3. The cooling apparatus of claim 1 , wherein air removed at said entry region and supplied from said heat exchanger to said cooling zone again flows in a direction opposite to said transport direction.

4. The cooling apparatus of claim 3 , further comprising:

a cool-air conducting duct being connected to said exit of said heat exchanger at one end thereof and to said cooling zone at a second end thereof.

5. The cooling apparatus of claim 4 , wherein said cool-air conducting duct comprises a plurality of nozzles which are configured for injecting cooled air into said cooling zone opposite to said transport direction.

6. The cooling apparatus of claim 1 , wherein said heat exchanger further comprises a fan for generating an air stream through said heat exchanger.

7. The cooling apparatus of claim 1 , wherein said heat exchanger is arranged within said housing.

8. The cooling apparatus of claim 1 , wherein said housing is closed so that essentially no air passes from said cooling zone to the outside.

9. The cooling apparatus of claim 1 , wherein workpieces passing through said entrance region have a temperature lower than 300° C.; and

wherein workpieces leaving said exit region have a temperature lower than 150° C.

10. The cooling apparatus of claim 1 , further comprising a precooling zone being arranged upstream of said cooling apparatus, as seen in the transport direction.

11. The cooling apparatus of claim 10 , further comprising a drier arranged upstream to said precooling zone, wherein air is extracted from said precooling zone and is supplied to said drier.

12. The cooling apparatus of claim 1 , further comprising an exhaust-air cooling apparatus being arranged downstream of said cooling apparatus, as seen in the transport direction.

13. A cooling system comprising a first cooling apparatus and a second cooling apparatus according to claim 1 , wherein an exit region of said first cooling apparatus is connected to an entrance region of said second cooling apparatus so that workpieces first pass through said first cooling apparatus, and thereafter through said second cooling apparatus.

14. A coating plant comprising a drier and a cooling apparatus according to claim 1 , wherein an exit side of said drier is connected to an entry side of said cooling apparatus so that at least part of a fresh-air supply into said drier is delivered from said cooling apparatus.

15. A cooling apparatus for cooling workpieces from a coating device, comprising:

a housing enclosing a cooling zone, said cooling zone having an entrance region communicating with an exit region;

a transport device extending though said housing for transporting workpieces along a transport direction through said entrance region, through said cooling zone and through said exit region;

a heat exchanger arranged within said housing, said heat exchanger comprising an entry and an exit through which a first fluid flow is guided, and further comprising pipes for guiding a second fluid flow therethrough and for transferring heat between said first and second fluid flows;

wherein said exit of said heat exchanger communicates with said cooling zone for supplying cooling air thereto, and wherein said entry of said heat exchanger communicates with said heat cooling zone for supplying warm air from said cooling zone to said heat exchanger and for transferring heat to said second fluid flow.

16. The cooling apparatus of claim 15 , in which air supplied to said heat exchanger from said cooling zone has an inlet temperature of between 40° C. and 250° C.

17. The cooling apparatus of claim 15 , wherein air removed at said entry region and supplied from said heat exchanger to said cooling zone again flows in a direction opposite to said transport direction.

18. The cooling apparatus of claim 17 , further comprising:

a cool-air conducting duct being connected to said exit of said heat exchanger at one end thereof and to said cooling zone at a second end thereof.

19. The cooling apparatus of claim 18 , wherein said cool-air conducting duct comprises a plurality of nozzles which are configured for injecting cooled air into said cooling zone opposite to said transport direction.

20. The cooling apparatus of claim 15 , wherein said heat exchanger further comprises a fan for generating an air stream through said heat exchanger.