Infrared-heated air knives for dryers

Patent metadata

Field	Value
Publication number	US-10308010-B2
Application number	US-201715427297-A
Country	US
Kind code	B2
Filing date	Feb 8, 2017
Priority date	Feb 8, 2017
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

Systems and methods are provided for enhanced dryers for printing systems. One embodiment is an apparatus that includes a dryer for a continuous-forms printing system. The dryer includes heating elements located within an interior of the dryer that radiate infrared energy onto a web of printed media as the web travels through the interior, and an air knife that is interposed between the heating elements. The air knife includes a shell that directly absorbs infrared energy from the heating elements and also defines a passage for air to travel through the air knife onto the web. The shell directly absorbs infrared energy from each heating element that would otherwise overlap on the web with infrared energy from another heating element.

First claim

We claim:

1. An apparatus comprising:
a dryer for a continuous-forms printing system, the dryer comprising:
heating elements located within an interior of the dryer that radiate infrared energy onto a web of printed media as the web travels through the interior; and
an air knife that is interposed between the heating elements, the air knife comprising a shell that directly absorbs infrared energy from the heating elements and also defines a passage for air to travel through the air knife onto the web,
wherein the shell directly absorbs infrared energy from each heating element that would otherwise overlap on the web with infrared energy from another heating element.

2. The apparatus of claim 1 wherein:
the shell directly prevents the formation of a region where infrared energy from multiple heating elements overlaps on the web.

3. The apparatus of claim 1 wherein:
air exiting the air knife is heated by at least ten degrees Celsius via convective heat transfer with an inner surface of the shell.

4. The apparatus of claim 1 wherein:
air exiting the air knife is heated above ambient temperature exclusively by forced convective heat transfer with an inner surface of the shell.

5. The apparatus of claim 1 wherein:
the shell defines an exit nozzle of the air knife.

6. The apparatus of claim 1 further comprising:
a return vent that draws air out of the dryer.

7. The apparatus of claim 6 wherein:
the return vent includes a baffle having slots of varying sizes along a length of the baffle, such that the slot size decreases in locations with higher air velocity and increases in locations with lower air velocity.

8. The apparatus of claim 6 wherein:
the return vent includes a vent plate which includes a varying pattern of holes along its length, such that the vent plate has fewer holes in locations with higher air velocity and more holes in locations with lower air velocity.

9. The apparatus of claim 6 wherein:
the dryer includes multiple return vents; and
each heating element is located between a return vent and the air knife.

10. The apparatus of claim 1 further comprising:
a fan that blows air across one or more of the heating elements.

11. An apparatus comprising:
multiple heating elements; and
an air knife interposed between the heating elements, the air knife comprising:

a shell comprising an exterior that directly absorbs infrared energy from the heating elements;
a passage defined by the shell; and
an inner surface of the shell heated by conductive heat transfer with the exterior the shell, wherein air exiting the air knife is heated by at least ten degrees Celsius via forced convective heat transfer with the shell.

12. The apparatus of claim 11 wherein:
the shell absorbs infrared energy from each heating element that would otherwise intersect with infrared energy from another heating element.

13. The apparatus of claim 11 wherein:
the shell reduces a size of a region in which infrared energy from the heating elements intersects.

14. The apparatus of claim 11 wherein:
air exiting the air knife is heated above ambient temperature exclusively by forced convective heat transfer with the inner surface of the shell.

15. The apparatus of claim 11 wherein:
the shell defines an exit nozzle of the air knife.

16. The apparatus of claim 11 wherein:
a distance between the exterior of the shell and the inner surface of the shell is less than two millimeters.

17. The apparatus of claim 11 wherein:
the shell comprises a material having a thermal conductivity of at least twenty Watts per meter Kelvin.

18. A method comprising:
operating heating elements within an interior of a dryer to radiate infrared energy onto a web of printed media as the web travels through the interior;
directly receiving infrared energy from the heating elements at a shell of an air knife; and
heating air exiting a passage of the air knife by at least ten degrees Celsius via forced convective heat transfer with the shell.

19. The method of claim 18 wherein:
directly receiving infrared energy from the heating elements at the shell absorbs infrared energy from each heating element that would otherwise overlap on the web with infrared energy from another heating element.

20. The method of claim 18 wherein:
directly receiving infrared energy from the heating elements at the shell reduces a size of a region in which infrared energy from the heating elements overlaps on the web.

Assignees

• Boland Stuart James
• Carson Graham James
• Johnson Scott Richard
• Ricoh Co Ltd

Inventors

• Boland Stuart James
• Carson Graham James
• Johnson Scott Richard

Classifications

• F26B21/50

  Ducting arrangements from the source of air or other gases to the materials or objects being dried · CPC title

• F26B13/00

  Machines and apparatus for drying fabrics, fibres, yarns, or other materials in long lengths, with progressive movement · CPC title

• B41J11/002

  Curing or drying the ink on the copy materials, e.g. by heating or irradiating · CPC title

• B41F23/0436

  using a combination of radiation, conduction or convection · CPC title

• F26B3/283

  in combination with convection · CPC title