Through-air dryer assembly

• US 20070051009A1
• Filed: 11/03/2006
• Published: 03/08/2007
• Est. Priority Date: 12/30/2003
• Status: Active Grant

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Frank Hada, Michael Hermans, Peter Costello, Ronald Gropp
• Inventors: Hermans, Michael, Costello, Peter, Gropp, Ronald, Hada, Frank
• Granted Patent: US 7,841,103 B2
• Time in Patent Office: Days
• US Class Current: 34/115
• CPC Class Codes: D21F 5/182 through perforated cylinders
• CPC Class Codes: D21F 5/184 Surfaces thereof
• CPC Class Codes: F26B 13/101 Supporting materials without tension, e.g. on or between foraminous belts
• CPC Class Codes: F26B 13/16 perforated in combination with hot air blowing or suction devices, e.g. sieve drum dryersF26B13/18 takes precedence

Abstract

A through-air dryer is disclosed. The through-air dryer includes a cylindrical deck made from a plurality of deck plates that support a throughdrying fabric. The deck plates are supported by opposing hubs. Each of the hubs is in communication with a bearing that is mounted to a stationary shaft for allowing the cylindrical deck and the hubs to rotate. The bearings are positioned so as to create a through-air dryer structure that remains stable during operation and allows for easy calculation of loads on the dryer.

Claims

1-30. -30. (canceled)

31. An apparatus for through-air drying webs comprising:

a cylindrical deck having sufficient open space to permit air flow therethrough;

a stationary support shaft concentrically positioned with respect to the cylindrical deck; and

a support structure positioned between the cylindrical deck and the support shaft for supporting the cylindrical deck, the support structure being configured to rotate on the support shaft, the support structure comprising a first hub spaced from a second hub, each hub engaging an opposite end of the cylindrical deck, the support structure further comprising a rotating tube surrounding the support shaft, the rotating tube being connected at a first end to the first hub and at a second end to the second hub.

32. An apparatus as defined in claim 31, wherein the support structure further comprises at least one internal deck support extending between the rotating tube and the cylindrical deck, and a deck support ring supporting the cylindrical deck in between the first end of the cylindrical deck and the second end of the cylindrical deck, the support ring being connected to the at least one internal deck support.

33. An apparatus as defined in claim 32, wherein the support structure includes a first internal deck support and a second internal deck support extending between the rotating tube and the cylindrical deck, each of the deck supports being connected to the deck support ring.

34. An apparatus as defined in claim 31, wherein the apparatus further comprises a first bearing and a second bearing, the first bearing being positioned between the first hub and the support shaft and the second bearing being positioned between the second hub and the support shaft, each bearing being substantially in alignment with each end of the cylindrical deck.

35. An apparatus as defined in claim 34, wherein the first and second bearings are located so that there is substantially no moment transfer between the cylindrical deck and the support structure.

36. An apparatus as defined in claim 31, further comprising a hood surrounding the cylindrical deck for directing a hot gaseous stream through the cylindrical deck or away from the cylindrical deck.

37. An apparatus as defined in claim 31, further comprising a throughdrying fabric wrapped around the cylindrical deck, the throughdrying fabric being configured to carry a web over a portion of the surface of the deck.

38. An apparatus as defined in claim 37, wherein the throughdrying fabric is wrapped around the cylindrical deck from an upstream point to a downstream point leaving an open free end, and wherein the apparatus further comprises an external baffle positioned over the open free end of the cylindrical deck, the external baffle shielding the open free end of the drying cylinder from external air.

39. An apparatus as defined in claim 31, wherein the cylindrical deck comprises a plurality of individual deck plates that are attached to the support structure.

40. An apparatus as defined in claim 39, wherein the individual deck plates are attached to the support structure using a pin attachment structure.

41. An apparatus as defined in claim 39, wherein the deck plates have a cross sectional profile that tapers in a direction opposite the direction of gas flow through the cylindrical deck.

42. An apparatus as defined in claim 39, wherein a load supported by the deck plates of the cylindrical deck is the sum of the following forces:

$\mathrm{\omega <br><br>}=w·<br><br>t·<br><br>l·<br><br>\mathrm{\delta <br><br>}$ $\mathrm{where}<br><br>\text{;<br><br>}<br><br><br><br>\mathrm{\omega <br><br>}=\mathrm{weight}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{per}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{unit}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{length}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{of}<br><br>\text{\hspace{1em}<br><br>}<br><br>a<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{deck}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{plate}$ $w=\mathrm{width}$ $t=\mathrm{thickness}$ $l=\mathrm{unit}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{length}$ $\mathrm{\delta <br><br>}=\mathrm{density}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{of}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{material}$ $F_p=2·<br><br>\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>P·<br><br>r_o·<br><br>l·<br><br>\sin <br><br>\left(\frac{\mathrm{\theta <br><br>}}{2}\right)$ $\mathrm{where}<br><br>\text{;<br><br>}$ $\mathrm{\theta <br><br>}=\mathrm{Change}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{in}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{angle}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{between}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{deck}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{plates}$ $r_o=\mathrm{Outside}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{radius}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{of}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{cylindrical}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{deck}$ $F_p=\mathrm{Force}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{from}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{differential}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{pressure}<br><br><br><br>l=\mathrm{Unit}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{length}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{of}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{plate}$ $F_n=l·<br><br>t·<br><br>\mathrm{\delta <br><br>}·<br><br>\frac{V_i^2}{2·<br><br>r_i^2}<br><br>\left(r_o^2-r_i^2\right)$ $\mathrm{where}<br><br>\text{;<br><br>}$ $F_n=\mathrm{Normal}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{force}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{on}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{bar}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{from}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{rotation}$ $t=\mathrm{thickness}$ $l=\mathrm{unit}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{length}$ $\mathrm{\delta <br><br>}=\mathrm{density}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{of}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{material}$ $V_i=\mathrm{Velocity}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{at}<br><br>\text{\hspace{1em}<br><br>}<br><br>“<br><br>r_i”<br><br>$ $r_i=\mathrm{radius}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{on}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{inside}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{of}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{support}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{bar}<br><br><br><br>r=\mathrm{distance}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{from}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{center}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{of}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{TAD};<br><br>\mathrm{and}$ $F_t=2·<br><br>T·<br><br>\sin <br><br>\left(\frac{\mathrm{\theta <br><br>}}{2}\right)$ $\mathrm{where}<br><br>\text{;<br><br>}$ $F_t=\mathrm{Force}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{per}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{unit}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{length}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{from}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{tension}<br><br><br><br>T=\mathrm{Fabric}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{tension}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{per}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{unit}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{length}$ $\mathrm{\theta <br><br>}=\mathrm{Change}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{in}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{angle}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{between}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{deck}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{plates}.$

43. An apparatus as defined in claim 33, wherein the first deck support and the second deck support have a conical shape for directing gas flow between the cylindrical deck and the first and second hubs and wherein the rotating tube shields the first bearing and the second bearing from the gas flow.

48. An apparatus as defined in claim 31, wherein the cylindrical deck and the support structure are configured to be disassembled, the apparatus having a disassembled volume when being shipped, the disassembled volume having a maximum dimension that is less than one-half the diameter of the cylindrical deck.

44-47. -47. (canceled)