Apparatus and method for the control of web or web-production machine component surface temperatures or for applying a layer of moisture to web

• US 4,763,424 A
• Filed: 04/27/1987
• Issued: 08/16/1988
• Est. Priority Date: 02/28/1986
• Status: Expired due to Fees

• Current Assignee: The Thermo Electron Web Systems Incorporated
• Original Assignee: The Thermo Electron Web Systems Incorporated
• Inventors: Taylor, Bruce F., Hagen, Kenneth G.
• Primary Examiner(s): Schwartz, Larry I.
• Application Number:
  US07/042,910
• Time in Patent Office: 477 Days
• Field of Search: 34/20, 34/114, 34/122, 34/155, 34/119, 34/124, 239/412
• US Class Current: 34/428
• CPC Class Codes: D21F 7/003 Indicating or regulating the moisture content of the layer
• CPC Class Codes: D21F 7/06 Indicating or regulating the thickness of the layer; Signal devices
• CPC Class Codes: D21G 7/00 Damping devices

Abstract

Disclosed is an apparatus and method for providing a shower of fog onto a web or a machine component in contact with a web or for applying a layer of moisture to a web. The fog, which as a temperature lower than the temperature of the surface of the web or the machine component to be cooled, is applied to the surface and is caused to evaporate by the difference in the temperatures. A supply of dry air is supplied to transport the evaporated fog from the region adjacent the surface to be cooled. Fog may be generated through the use of an air-atomizing nozzle which propels water and compressed air through a small orifice under pressure to create an atomized mist or fog. To achieve localized control of the application of fog, a plurality of air atomizing nozzles is mounted in a row extending in the cross machine direction of the apparatus. An air plenum extending parallel to the row of air atomizing nozzles is mounted on at least one side of the row. Each air plenum includes a slot that directs an air curtain toward the mist flow from the nozzle to restrict the flow to a uniformly dimensioned area.

Claims

1. An apparatus for use in the non-contact cooling of a web or for applying a layer of moisture to a web, said apparatus being positioned adjacent said web or component to be cooled, said apparatus comprising:

means for creating fog within said apparatus, said fog having a temperature lower than the temperature of said web or component to be cooled;

means for directing said created fog in a stream from said apparatus to the web;

means for directing an air stream toward said fog stream to confine the impingement of said fog stream on the web to a uniform selected region on the web.

2. The apparatus for use in the non-contact cooling of a web or for applying a layer of moisture to a web of claim 1 wherein said means for creating fog comprises:

compressed-air supply means and compressed air supply valve means connected to said compressed-air supply means for controlling the release of compressed air from said compressed-air supply means;

water supply means and water supply valve meens connected to said water supply means for controlling the re1ease of water from said water supply means;

air-atomizing nozzle means for receiving compressed air from said compressed air supply means and water from said water supply means, said air-atomizing nozzle means providing a flow of fog to a chamber in said apparatus.

3. The apparatus for use in the non-contact cooling of a web or for applying a layer of moisture to a web cf claim 2 wherein said air atomizing nozzle means comprises:

a needle valve postioned within a water input orifice of said air atomizing nozzle means;

control means for controlling the position of said needle value within said water input orifice.

4. The apparatus or use in the non-contact cooling of a web or for applying a layer of moisture to a web of claim 3 wherein said control means comprises a stepping motor and a lead screw device coupled between stepping motor and a shaft of said needle valve.

5. The apparatus for use in the non-contact cooling of a web or for applying a layer of moisture to a web of claim 1 wherein said means for directing an air stream toward said fog stream comprises:

an air plenum having an outlet slot directed toward a point downstream from said means for directing fog between said means for directing fog and the web so that the air stream from said air plenum passing through said outlet slot contacts the fog before the fog impinges on the web.

6. The apparatus for use in the non-contact cooling of a web or for applying a layer of moisture to a web of claim 5 wherein said means for directing an air stream toward said fog stream comprises:

at least two air plenums with each of said air plenums having a slot directed toward a point downstream from said means for directing fog between said means for directing fog and the web so that the air stream from said air plenums passing through said outlet slots contact the fog before the fog impinges on the web.

7. The apparatus for use in the non-contact cooling of a web or for applying a layer of moisture to a web of claim 2 wherein said means for directing an air stream toward said fog stream comprises:

an air plenum having an outlet slot directed toward a point downstream from said means for directing fog between said means for directing fog and the web so that the air stream from said air plenum passing through said outlet slot contacts the fog before the fog impinges on the web.

8. The apparatus for use in the non-contact cooling of a web or for applying a layer of moisture to a web of claim 7 wherein said means for directing an air stream toward said fog stream comprises:

at least two air plenums with each of said air plenums having a slot directed toward a point downstream from said means for directing fog between said means for directing fog and the web so that the air streams from said air plenums passing through said outlet slots contact the fog before the fog impinges on the web.

9. The apparatus for use in the non-contact cooling of a web or for applying a layer of moisture to a web of claim 7 wherein said apparatus comprises a plurality of air atomizing nozzle means mounted on said apparatus in a row extending in the cross machine direction of said apparatus and wherein said air plenum extends parallel to said row of air atomizing nozzle means in the cross machine direction of said apparatus.

10. The apparatus for use in the non-contact cooling of a web or for applying a layer of moisture to a web cf claim 8 wherein said apparatus comprises a plurality of air atomizing nozzle means mounted on said apparatus in a row extending in the cross machine direction of said apparatus and wherein at least one air plenum is mounted on each side of said row of air atomizing nozzle means, each air plenum extending parallel to said row of air atomizing nozzle means in the cross machine direction of said apparatus.

11. The apparatus for use in the non-contact cooling of a web or for applying a layer of moisture to a web of claim 2 wherein said compressed air supply valve means is constantly open.

12. The apparatus for use in the non-contact cooling of a web or for applying a layer of moisture to a web of claim 1 further comprising:

means for providing a supply of carrying air within a housing enclosing said means for directing said created fog, said housing including a wall with a slot directed in substantially the same direction as said means for directing fog directs fog;

means for deflecting air passing through said slot towards said fog stream so that said air comes in contact with said fog stream.

13. The apparatus for use in the non-contact cooling of a web or for applying a layer of moisture to a web of claim 12 wherein said means for deflecting air comprises a wall positioned in front of said slot so that air passing through said slot strikes said wall and is directed towards said fog stream.

14. A method for the non-contact cooling of a web or for applying a layer of moisture to a web, said method comprising the steps of:

creating a supply of fog and directing fog in a fog stream from said created supply of fog to the web;

directing an air stream toward said fog stream to confine the impingement of said fog stream on the web to a uniform selected region on the web.

15. The method for the non-contact cooling of a web or for applying a layer of moisture to a web of claim 14 wherein said step of directing an air stream towards said fog stream comprises:

providing an air plenum having an outlet slot directed toward a point downstream from where fog is discharged from said supply of fog so that the air stream from said air plenum passing through said outlet slot contacts the fog before the fog impinges on the web.

16. The method for the non-contact cooling of a web or for applying a layer of moisture to a web of claim 15 wherein at least two air plenums are provided with each of said air plenums having a slot directed toward a point downstream from the point of discharge from the fog toward the wet so that the air streams from the air plenums passing through said outlet slots contact the fog before the fog impinges on the web.

17. The method for the non-contact cooling of a web or for applying a layer of moisture to a web of claim 15 wherein fog is directed from a series of spaced apart locations aligned in a row across the width of the machine through which the web travels and wherein said air plenum is mounted parallel to said row.

18. The method for the non-contact cooling of a web or for applying a layer of moisture to a web of claim 16 wherein fog is discharged from a series of spaced apart locations arranged in a row extending across the width of a machine through which the sheet travels and wherein at least one air plenum is mounted on each side of said row with each air plenums extending parallel to the row.