Calender humidity control system and method

• US 6,694,640 B1
• Filed: 02/04/2000
• Issued: 02/24/2004
• Est. Priority Date: 02/06/1999
• Status: Expired due to Fees

• Current Assignee: Voith Sulzer Papiertechnik Patent GmbH (Voith GmbH & Co. KGaA)
• Original Assignee: Voith Sulzer Papiertechnik Patent GmbH (Voith GmbH & Co. KGaA)
• Inventors: Kayser, Franz
• Primary Examiner(s): Doerrler, William C.
• Assistant Examiner(s): SHULMAN, MARK S
• Application Number:
  US09/497,797
• Time in Patent Office: 1,481 Days
• Field of Search: 341/14, 341/16, 341/22, 344/44, 344/45, 344/46, 344/74, 344/76, 344/91, 345/28, 345/57
• US Class Current: 34/402
• CPC Class Codes: D21G 1/00 Calenders if restricted to the treatment of particular materials see the relevant class, e.g. B29C43/24, D06; Smoothing apparatus
• CPC Class Codes: D21G 1/0093 Web conditioning devices

Abstract

A calender, a system, and a method of regulating the humidity in a calender. The calender includes a housing having at least two side pieces and a roll stack located at least partially between the side pieces, wherein a space is formed by the roll stack and the web between the side pieces, and a fan positioned to blow dry air into the space. The system is for regulating the humidity in a calender, the calender being used to treat a moisture-containing material web and including a housing having at least two side walls and a roll stack, the calender defining a space bounded at least by the roll stack, the web, and the at least two side walls, and includes a device for reducing the humidity of the space, wherein the humidity level in the space is reduced to a level which is below a saturation point. The method includes reducing the humidity of the space, wherein the humidity level in the space is reduced to a level which is below a saturation point.

Claims

1. A calender for webs of moisture-containing material, comprising:

a housing having at least two side pieces and a-roll stack located at least partially between the side pieces, wherein a space is formed by the roll stack and the web between the side pieces; and

a fan positioned to blow dry air into the space.

2. The calender of claim 1, wherein the material web comprises a paper web.

3. The calender of claim 1, wherein the dry air blown into the space comprises a relative humidity which is lower than the relative humidity of the air disposed in the space.

4. The calender of claim 1, further comprising a heating device for heating the dry air.

5. The calender of claim 1, further comprising at least one moisture sensor for measuring a humidity of the space and communicating the measurement to a computer.

6. The calender of claim 5, further comprising at least one temperature sensor for measuring a temperature of the space and communicating the measurement to a computer.

7. The calender of claim 6, further comprising a computer which receives inputs from the at least one moisture sensor and the at least one temperature sensor for adjusting the humidity of the space.

8. The calender of claim 7, further comprising an air adjusting device for regulating one of the air velocity entering the space and the quantity the air entering the space.

9. The calender of claim 8, wherein the air adjusting device comprises a computer controlled fan adjusting motor.

10. The calender of claim 7, further comprising an temperature adjusting device for regulating the temperature of the dry air entering the space.

11. The calender of claim 10, wherein the temperature adjusting device comprises a computer controlled adjustable heating current regulator.

12. The calender of claim 7, further comprising a computer program which manipulates input measurements from the at least one moisture sensor and the at least one temperature sensor and calculates outputs for regulating the humidity level within the space in the range of between approximately 75% and 95%.

38. The calender of claim 1, further comprising at least one opening formed in at least one of the at least two side pieces, wherein the space is open to an ambient atmosphere through the at least one opening.

13. A system for regulating the humidity in a calender, the calender being used to treat a moisture-containing material web and including a housing having at least two side walls and a roll stack, the calender defining a space bounded at least by the roll stack, the web, and the at least two side walls, the system comprising:

a device for reducing the humidity of the space,

wherein the humidity level in the space is reduced to a level which is below a saturation point.

14. The system of claim 13, wherein the device for reducing the humidity comprises an air exchanging device.

15. The system of claim 13, wherein the device for reducing the humidity comprises a fan for removing air from the space.

16. The system of claim 13, wherein the device for reducing the humidity comprises a fan for blowing air into the space.

17. The system of claim 16, further comprising a heating device for heating the air.

18. The system of claim 13, further comprising at least one moisture sensor for measuring a humidity in the space and communicating the measurement to a regulating device.

19. The system of claim 18, further comprising at least one temperature sensor for measuring a temperature in the space and communicating the measurement to a regulating device.

20. The system of claim 19, wherein the regulating device comprises a computer which receives inputs from the at least one moisture and the at least one temperature sensors for adjusting the humidity of the space.

21. The system of claim 20, further comprising an air adjusting device for regulating one of the air velocity entering the space and the quantity the air entering the space.

22. The system of claim 21, wherein the air adjusting device comprises a computer controlled fan adjusting motor.

23. The system of claim 20, further comprising an temperature adjusting device for regulating the temperature of air entering the space.

24. The system of claim 23, wherein the temperature adjusting device comprises a computer controlled adjustable heating current regulator.

25. The system of claim 20, further comprising a computer program which manipulates input measurements from the at least one moisture sensor and the at least one temperature sensor and calculates outputs for regulating the humidity level within the space in the range of between approximately 75% and 95%.

39. The system of claim 13, further comprising at least one opening formed in at least one of the at least two side walls, wherein the space is open to an ambient atmosphere through the at least one opening.

26. A method of regulating the humidity in a calender, the calender being used to treat a moisture-containing material web and including a housing having at least two side walls and a roll stack, the calender defining a space bounded at least by the roll stack, the web, and the at least two side walls, the method comprising:

reducing the humidity of the space,

wherein the humidity level in the space is reduced to a level which is below a saturation point.

27. The method of claim 26, wherein the reducing further comprises:

exchanging the air of the space with an air exchanging device.

28. The method of claim 26, wherein the reducing further comprises:

introducing air to the space using a fan.

29. The method of claim 26, wherein the reducing further comprises:

removing air from the space using an exhaust fan.

30. The method of claim 26, further comprising:

introducing air to the space using a fan.

31. The method of claim 26, further comprising:

measuring the humidity in the space with at least one sensor.

32. The method of claim 31, further comprising:

regulating the humidity of the space using a control device which receives inputs from the at least one sensor.

33. The method of claim 32, wherein the at least one sensor comprises at least one moisture sensor, and the method further comprises:

regulating the humidity of the space using a regulating device which receives inputs from the at least one moisture sensor.

34. The method of claim 33, wherein the at least one sensor comprises at least one temperature sensor, and the method further comprises:

regulating the humidity of the space using a control device which receives inputs from the at least one temperature sensor.

35. The method of claim 34, wherein the regulating further comprises:

maintaining the humidity in the space in the range of between approximately 75% and 95%.

40. The method of claim 26, wherein at least one of the at least two side walls includes at least one opening, whereby the space is open to an ambient atmosphere through the at least one opening.

36. A system for regulating the humidity in a calender, the calender being used to treat a moisture-containing material web and including a housing having at least two side walls and a roll stack, the calender defining a space bounded at least by the roll stack, the web, and the at least two side walls, the system comprising

a device for reducing the humidity of the space;

at least one moisture sensor disposed within the space;

at least one temperature sensor disposed within the space;

a control device for receiving inputs from the at least one moisture sensor and the at least one temperature sensor;

wherein the control device controls the device for reducing the humidity so as to regulate the humidity level in the space to a point which is below a saturation point.

41. The system of claim 36, further comprising at least one opening formed in at least one of the at least two side walls, wherein the space is open to an ambient atmosphere through the at least one opening.

37. A method of regulating the humidity in a calender, the calender being used to treat a moisture-containing material web and including a housing having at least two side walls and a roll stack, the calender defining a space bounded at least by the roll stack, the web, and the at least two side walls, the method comprising:

measuring the humidity within the space with at least one moisture sensor;

measuring the temperature within the space with at least one temperature sensor;

comparing the humidity of the space to a desired value in a range using a computer which receives inputs from the at least one moisture sensor and the at least one temperature sensor; and

regulating the humidity of the space to the desired value,

wherein the humidity level in the space is reduced to a level which is within the range of between approximately 75% and 95%.

42. The method of claim 37, wherein at least one of the at least two side walls includes at least one opening, whereby the space is open to an ambient atmosphere through the at least one opening.