Abstract:
An adjustable deckel profiler is disclosed, for use in apparatus for drying a moving paper web. The profiler is a slidable member which interacts with impingement air to control and adjust the air against the moving web. Means are provided for adjusting and setting the profiler relative to cross machine drying air profiling.

Description:
FIELD OF THE INVENTION 
     This invention relates to drying systems for web material such as tissue, pulp and paper and using an adjustable deckel in the drying process. 
     BACKGROUND OF THE INVENTION 
     In web drying processes it is very important to maintain a uniform edge moisture profile in the cross machine direction and in the machine direction on papermaking drying machines such as paper, pulp and tissue machines, in order to achieve high quality paper production. 
     Uneven moisture edge profiles can result in overheating of cylinder edges causing over-dried edges of the web, uneven creping on tissue machines, excessive local wear of tissue cylinders, reduced machine production and increase in raw material consumption. 
     There are several profiling devices on the market, but none of those provide the profiling requirements need in today&#39;s industry. The following United States patents provide several examples: 
     U.S. Pat. No. 4,312,139 discloses a material web dryer having opening and closing elements for controlling discharge between open, partially closed, or completely closed positions; 
     U.S. Pat. No. 3,962,799 discloses a moisture profiler for contacting a moving web, having a pair of sliding valves overlying the inlets from ducts to adjust the hot to warm air ratio; 
     U.S. Pat. No. 4,331,150 discloses a steam shower for reducing paper web moisture content in a cross machine direction by varying it&#39;s bottom steam discharge area incrementally across the web; 
     U.S. Pat. No. 4,192,080 discloses a method for improving the drying characteristics of a cylinder drying section of a paper machine having an even transverse moisture profile; 
     U.S. Pat. No. 4,545,857 discloses a steam box for controlling the moisture content of a paper web, which delivers steam to a series of damper controlled compartments that extend across the web; 
     U.S. Pat. No. 3,930,319 discloses an apparatus for drying a travelling paper web, having a hot air delivery system adjacent the cylinder, with at least a part of the hot air delivery structure being transversely movable; and 
     U.S. Pat. No. 3,263,344 discloses a drying system for a papermaking machine having sleeves that allow transverse movement so that the air discharge can be controlled. 
     SUMMARY OF THE INVENTION 
     The present invention addresses the problem of edge sheet uniformity in the drying section of paper, pulp and especially on tissue drying apparatus. It also addresses the problems associated with hot air spillage caused by dryer air boundary layer and balancing of the process air drying equipment. 
     According to a broad aspect the invention relates to an adjustable deckel profiler for use in an apparatus for drying a moving web of tissue, pulp or paper, said profiler comprising a slidable member for controlling and adjusting hot process impingement air onto said web and which operatively increases or decreases the process air impinging on said web, and means for adjusting and setting said profiler relative to cross-machine drying air profiling. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a cross-sectional view of a side area of a web drying apparatus illustrating the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the drawing, a sectional view of a preferred embodiment of the invention in a material web drying apparatus, is shown. The web drying apparatus includes a cylinder  10  which carries the material sheet  12  to be dried. A nozzle box  14  has upper and lower walls  16 ,  18  respectively, lower wall  18  being provided with a plurality of apertures  20  through which hot, pressurized air as indicated by the arrows  22  is directed onto the web  12  in the drying process. 
     In order to provide as much control as possible over the local sheet moisture variances during the drying process, a deckel profiler indicated generally at  24  is provided at the end wall of the nozzle box  14 . The profiler  24  is adapted to control and adjust the hot process impingement air onto the web  12  at the marginal areas thereof by means of a sliding member  26  telescopically mounted in the end wall area of the nozzle box  14 . As illustrated, the member  26  has a bottom wall  28  that incorporates a plurality of apertures  30  in the form of an adjustable deckel  32 . Apertures  30  in the bottom wall  28  of the member are adapted to interact with other apertures  34  spaced along a spillage controller plate  36  which lies intermediate the bottom wall  28  of the slidable member and the bottom wall  18  of the nozzle box  14 . It will be appreciated that by moving the slidable member  26  inwardly or outwardly of the nozzle box (to the right or to the left in the drawing) the amount of pressurized air from the interior of the nozzle box being directed through the apertures  34  can be varied depending on the location of the associated apertures  30  in the slidable member  26 . Thus, the deckel profiler  24  can control and adjust the hot process impingement air  22  onto the paper sheet in the marginal area thereof, increasing or decreasing the hot process air impinging on the sheet in that area. 
     The profiler  24  is adapted to provide very small incremental edge cross-machine profiling adjustments and this is accomplished by means of individual adjusters  38 . The adjuster  38  consists of an elongated bolt  40  having a tool-engaging outer end  42  and which is threadably engaged for inward and outward movement in a sleeve  44  which is welded to a wall  46  secured to the outer end wall  48  of the nozzle box  14 . As shown, wall  46  is provided with an aperture  50  through which the inner end of the bolt  40  extends, eventually entering the confines of the slidable member  26 . In that regard, member  26  is provided with an end wall  52  and a pair of washers  54  on the inner end of the bolt  40  engage either side of the wall  52  and are secured in place by means of a nut  56  threaded onto the inner terminal end of bolt  40 . 
     Outwardly of the sleeve  44 , bolt  40  is provided with a plurality of seals  58  that are concentrically mounted on the bolt  40  and these sit in a shoulder  60  on the sleeve  44 . A seal securing sleeve  62  is slidably mounted over the surface of bolt  40  to engage the seals  58  and pressure on the sleeve  62  and seals  58  is applied by a cup  64  threadably engaging the outer end of sleeve  44  and drawing down on pressure washers  66 . 
     As shown in the drawing, the outer end of bolt  40  is provided with a series of indicator rings or other suitable markings  68 . 
     In operation, the bolt  40  is adjusted inwardly or outwardly by means of rotating the tool engaging end  42  thereof and this action provides a fine inward or outward movement of the slidable member  26  whereby the apertures  30  in the bottom wall thereof either cover or uncover portions of or all of apertures  34  in the spillage controller plate  36 . Thus, the profiler  24  provides the capability of controlling process air  22  as well as the cylinder dryer boundary air layer spillage in the area illustrated. The directional control feature in the plate  36  and apertures  30  and  34  provide that control by varying the geometrical configuration of the lower plate through movement of the member  26 . 
     The result of this control will provide more even drying of a sheet in the area described and it will also reduce sheet trimming requirements due to its accurate hot air impingement control onto the sheet  12 . 
     The present invention also provides improvements in edge moisture profiling correction on the tending and drive sides of a drying machine; individual adjustment over the full range of the periphery of the drying apparatus; edge spillage control; control capability of wet and dryer sheet edges; and a reduction in the overheating of edge cylinder surfaces. 
     While the invention has been described in connection with a specific embodiment thereof and in a specific use, various modifications thereof will occur to those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims. 
     The terms and expressions which have been employed in this specification are used as terms of description and not of limitations, and there is no intention in the use of such terms and expressions to exclude any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claims.