US20110139391A1

US20110139391A1 - Transfer apparatus

Info

Publication number: US20110139391A1
Application number: US12/653,369
Authority: US
Inventors: James Albertus Anema; Laurie David Wicks
Original assignee: James Albertus Anema; Laurie David Wicks
Current assignee: JOHNSONFOILS Inc; Paperchine Inc
Priority date: 2009-12-10
Filing date: 2009-12-10
Publication date: 2011-06-16

Abstract

A transfer apparatus is disclosed for transferring a light weight web from a dewatering section to a Yankee dryer. The transfer apparatus includes a looped transfer blanket which is disposed between the dewatering section and the Yankee dryer for supporting and transporting the web from the dewatering section towards the Yankee dryer. The dewatering section includes a press which defines a press nip for the passage therethrough of the web. The press nip assists in dewatering the web and guides the web. A press felt extends through the press nip and the transfer blanket also extends through the press nip. A roll is disposed downstream relative to the press nip for transferring the web from the transfer blanket and for guiding the web towards the Yankee dryer.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a transfer apparatus.
More specifically, the present invention relates to a transfer apparatus for transferring a light weight web from a dewatering section to a Yankee dryer.
2. Background Information
On lightweight grades such as tissue and Machine Glazed (MG) grades, it is important to have a closed draw between the forming section and the Yankee dryer for good machine efficiency.
On typical prior art machines, the sheet is transferred from the forming section to the Yankee dryer on a pick up felt. The sheet is transferred to the Yankee dryer with a pressure roll. In order to improve the dryness of the sheet prior to the Yankee dryer, there are often one or more presses. These presses are double felted and typically have a suction roll inside the pick up roll loop to insure that the paper follows the pick up felt after the press nip. The use of a suction roll is necessary to transfer the sheet to the pick up felt after the nip. However, suction rolls limit the load that can be applied in the nip to remove water due to their inherent strength limitations. In addition, a double felted press on these lightweight grades, (less then 78 pounds per 3000 sq. ft.) results in significant rewet of the web by water from the bottom felt into the sheet thereby minimizing the water removal efficiency of the press.
The purpose of the present invention is to replace the bottom felt with a transfer belt or blanket that will carry the sheet without rewetting the sheet in the sheet transfer process. The transfer belt or blanket is impervious to water and has a smooth surface so the sheet will adhere to the transfer belt or blanket after the press nip without the use of a suction roll.
According to the present invention there are two presses ahead of the pressure roll. The bottom felt on the second press has been replaced with a transfer belt or blanket. Following the second press, the sheet will follow the transfer belt or blanket since it has a smoother surface compared to the top felt. This allows the suction roll to be eliminated in the press and replaced with either a plain roll or a shoe press that allows much higher loads to be applied to the sheet in the press which results in much greater water removal. The sheet is carried to a transfer roll which uses vacuum to transfer the sheet to the pressure roll felt and onto the Yankee dryer surface. Since the transfer belt or blanket carries no water, there is no water transferred into the sheet while the sheet of paper is in contact with the transfer belt as well as when the sheet is transferred from the transfer belt to the pressure roll felt with a suction transfer roll.
In a similar but alternative arrangement, the transfer roll is eliminated and a suction roll is used in the pressure roll position to transfer the sheet from the transfer belt as well as apply the sheet to the Yankee dryer.
Therefore, a primary feature of the present invention is the provision of a transfer apparatus that overcomes the problems associated with the prior art arrangements.
Another feature of the present invention is the provision of a transfer apparatus that inhibits rewetting of the web.
Other features and advantages of the present invention will be readily apparent to those skilled in the art by a consideration of the detailed description of a preferred embodiment of the present invention contained herein.

SUMMARY OF THE INVENTION

The present invention relates to a transfer apparatus for transferring a light weight web from a dewatering section to a Yankee dryer.
The transfer apparatus according to the present invention includes a looped transfer blanket which is disposed between the dewatering section and the Yankee dryer for supporting and transporting the web from the dewatering section towards the Yankee dryer. The dewatering section includes a press which defines a press nip for the passage therethrough of the web. The press nip assists in dewatering the web and guides the web. A press felt extends through the press nip and the transfer blanket also extends through the press nip. A roll is disposed downstream relative to the press nip for transferring the web from the transfer blanket and for guiding the web towards the Yankee dryer.
In one embodiment of the present invention, the press includes a press roll for guiding the web. A backing roll cooperates with the press roll such that the press roll and the backing roll define therebetween the press nip for the passage therethrough of the web. The press felt extends through the press nip such that the press felt is disposed between the press roll and the web during passage of the press felt and the web through the press nip. The transfer blanket extends through the press nip such that the transfer blanket is disposed between the backing roll and the web during passage of the transfer blanket and the web through the press nip.
In another embodiment of the present invention, the dewatering section includes an elongate press shoe for guiding the web. A backing roll co-operates with the press shoe for defining therebetween an extended nip for the passage therethrough of the web. A press felt extends through the extended nip such that the press felt is disposed between the press shoe and the web during passage of the press felt and the web through the extended nip. The transfer blanket extends through the extended nip such that the transfer blanket is disposed between the backing roll and the web during passage of the transfer blanket and the web through the extended nip. A roll is disposed downstream relative to the extended nip for transferring the web from the transfer blanket and for guiding the web towards the Yankee dryer.
In a more specific embodiment of the present invention, the looped transfer blanket is impervious to water. The arrangement is such that during transit of the web supported by the transfer blanket between the extended nip and the roll, rewetting of the web is inhibited.
Also, the roll is a transfer roll for transferring the web from the looped transfer blanket.
Furthermore, the transfer apparatus includes a pressure roll which is disposed downstream relative to the transfer roll.
Moreover, a pressure roll felt extends around the transfer roll and the pressure roll such that when the web is transferred by the transfer roll from the transfer blanket to the pressure roll felt, the web is thereafter guided and supported by the pressure roll felt to and around the pressure roll. The arrangement is such that the web is transferred from the pressure roll felt to the Yankee dryer for drying of the web.
More specifically, the transfer roll is a suction transfer roll.
In another embodiment of the present invention, the roll is a suction pressure roll for transferring the web from the looped transfer blanket.
Also, the transfer apparatus includes the pressure roll felt which extends around the suction pressure roll such that when the web is transferred by the suction pressure roll from the transfer blanket to the pressure roll felt, the web is thereafter guided and supported by the pressure roll felt around the suction pressure roll so that the web is transferred from the pressure roll felt to the Yankee dryer for drying of the web.
Additionally, a press section is disposed upstream relative to the extended nip. The press section includes a press roll.
A further backing roll co-operates with the press roll for defining therebetween a press nip for the passage therethrough of the web.
Also, a pick up felt extends through the press nip such that the pick up felt is disposed between the press roll and the web during passage of the pick up felt and the web through the press nip.
A further press felt extends through the press nip such that the further press felt is disposed between the further backing roll and the web during passage of the further press felt and the web through the press nip.
Furthermore, a suction roll is disposed downstream relative to the press nip and upstream relative to the extended nip. The suction roll co-operates with the further press felt for transferring the web from the further press felt to the press felt.
Additionally, the web is disposed between the further press felt and the press felt.
Moreover, the pick up felt co-operates with a forming section for transferring the web from the forming section to the pick up felt.
In a further embodiment of the present invention, a pressing roll co-operates with the backing roll for defining a pressing nip therebetween. The pressing nip is disposed upstream relative to the extended nip.
Furthermore, a pick up felt extends between the pressing roll and the backing roll so that the web is disposed between the pick up felt and the backing roll during passage of the web through the pressing nip. The pick up felt picks up the web from an upstream forming section.
A first press roll co-operates with the pressing roll for defining a first press nip therebetween. The first press nip is disposed upstream relative to the pressing nip.
Moreover, a pressing felt extends between the pressing roll and the first press roll so that the web is disposed between the pressing felt and the pick up felt during passage of the web through the first press nip.
Many modifications and variations of the present invention will be readily apparent to those skilled in the art by a consideration of the detailed description contained hereinafter taken in conjunction with the annexed drawings which show a preferred embodiment of the present invention. However, such modifications and variations fall within the spirit and scope of the present invention as defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a transfer apparatus according to a first embodiment of the present invention;

FIG. 2 is a side elevational view of a second embodiment of the present invention;

FIG. 3 is a side elevational view of a third embodiment of the transfer apparatus shown in FIGS. 1 and 2.

Similar reference characters with suffixes added thereto refer to similar parts throughout the various embodiments shown in the drawings.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a transfer apparatus generally designated 10 according to a first embodiment of the present invention. As shown in FIG. 1, the transfer apparatus 10 is for transferring a light weight web W from a dewatering section generally designated 12 to a Yankee dryer 14.
The transfer apparatus 10 includes a looped transfer blanket 16 which is disposed between the dewatering section 12 and the Yankee dryer 14 for supporting and transporting the web W from the dewatering section 12 towards the Yankee dryer 14. The dewatering section 12 includes a press generally designated 17. The press 17 defines a press nip 19 for the passage therethrough of the web W. The press nip 19 assists in dewatering the web W and guides the web W. A press felt 24 extends through the press nip 19 and the transfer blanket 16 also extends through the press nip 19. A roll 26 is disposed downstream relative to the press nip 19 for transferring the web W from the transfer blanket 16 and for guiding the web W towards the Yankee dryer 14.
In one embodiment of the present invention, as shown in FIG. 1, the press 17 includes a press roll 21 for guiding the web W. A backing roll 20 cooperates with the press roll 21 such that the press roll 21 and the backing roll 20 define therebetween the press nip 19 for the passage therethrough of the web W. The press felt 24 extends through the press nip 19 such that the press felt 24 is disposed between the press roll 21 and the web W during passage of the press felt 24 and the web W through the press nip 19. The transfer blanket 16 extends through the press nip 19 such that the transfer blanket 16 is disposed between the backing roll 20 and the web W during passage of the transfer blanket 16 and the web W through the press nip 19.
FIG. 2 is a side elevational view of a second embodiment of the present invention. As shown in FIG. 2, the dewatering section 12 a includes an elongate press shoe 18 for guiding the web Wa. A backing roll 20 a co-operates with the press shoe 18 for defining therebetween an extended nip 22 for the passage therethrough of the web Wa. A press felt 24 a extends through the extended nip 22 such that the press felt 24 a is disposed between the press shoe 18 and the web Wa during passage of the press felt 24 a and the web Wa through the extended nip 22. The transfer blanket 16 a extends through the extended nip 22 such that the transfer blanket 16 a is disposed between the backing roll 20 a and the web Wa during passage of the transfer blanket 16 a and the web Wa through the extended nip 22. A roll 28 a is disposed downstream relative to the extended nip 22 for transferring the web Wa from the transfer blanket 16 a and for guiding the web Wa towards the Yankee dryer 14 a.
Those skilled in the art will appreciate that the location of the press shoe 18 and the backing roll 20 a could be interchanged so that the transfer blanket 16 a could serve the further function of a bearing blanket for supporting web Wa through the extended nip 22. In such an arrangement, the blanket 16 a would physically slide over the lubricated surface of the shoe 18 with the blanket 16 a disposed between the shoe 18 and the web Wa.
In all of the embodiments of the present invention, the looped transfer blanket 16, 16 a is impervious to water such that during transit of the web W, Wa supported by the transfer blanket 16, 16 a between the extended nip 22 and the roll 28, 28 a, rewetting of the web W, Wa is inhibited.
As shown in FIG. 1, the roll 26 is a transfer roll for transferring the web W from the looped transfer blanket 16.
Additionally, as shown in FIG. 1, the transfer apparatus 10 includes a pressure roll 28 which is disposed downstream relative to the transfer roll 26.
Moreover, a pressure roll felt 30 extends around the transfer roll 26 and the pressure roll 28 such that when the web W is transferred by the transfer roll 26 from the transfer blanket 16 to the pressure roll felt 30, the web W is thereafter guided and supported by the pressure roll felt 30 to and around the pressure roll 28. The arrangement is such that the web W is transferred from the pressure roll felt 30 to the Yankee dryer 14 for drying of the web W. Thus, the web is supported without any open draws between the extended nip 22 and the Yankee dryer 14.
More specifically, the transfer roll 26 is a suction transfer roll.
As shown in FIG. 2, the transfer apparatus 10 a includes a suction pressure roll 28 a which transfers the web Wa from the looped transfer blanket 16 a.
Also, the transfer apparatus 10 a includes a pressure roll felt 30 a which extends around the suction pressure roll 28 a such that when the web Wa is transferred by the suction pressure roll 28 a from the transfer blanket 16 a to the pressure roll felt 30 a, the web Wa is thereafter guided and supported by the pressure roll felt 30 a around the suction pressure roll 28 a so that the web Wa is transferred from the pressure roll felt 30 a to the Yankee dryer 14 a for drying of the web Wa.
As shown in FIGS. 1 and 2, additionally, a press section generally designated 32 is disposed upstream relative to the press nip 19. The press section 32 includes a pressing roll 34.
A further backing roll 36 co-operates with the pressing roll 34 for defining therebetween a pressing nip 38 for the passage therethrough of the web W, Wa.
Also, a pick up felt 40 extends through the pressing nip 38 such that the pick up felt 40 is disposed between the pressing roll 34 and the web W, Wa during passage of the pick up felt 40 and the web W, Wa through the pressing nip 38.
A further press felt 42 extends through the pressing nip 38 such that the further press felt 42 is disposed between the further backing roll 36 and the web W, Wa during passage of the further press felt 42 and the web W, Wa through the pressing nip 38.
Furthermore, a suction roll 44 is disposed downstream relative to the pressing nip 38 and upstream relative to the extended nip 22. The suction roll 44 co-operates with the further press felt 42 for transferring the web W, Wa from the further press felt 42 to the press felt 24.
Additionally, the web W, Wa is disposed between the further press felt 42 and the press felt 24, 24 a.
Moreover, the pick up felt 40 co-operates with a forming section generally designated 46 for transferring the web W, Wa from the forming section 46 to the pick up felt 40.
FIG. 3 is a side elevational view of a further embodiment of the transfer apparatus 10, 10 a shown in FIGS. 1 and 2. As shown in FIG. 3, a suction pressing roll 48 co-operates with the backing roll 20 b for defining a nip 50 therebetween. The nip 50 is disposed upstream relative to an extended nip 22 b.
Furthermore, a further pick up felt 58 extends between the suction pressing roll 48 and the backing roll 20 b so that the web Wb is disposed between the further pick up felt 58 and the backing roll 20 b during passage of the web Wb through the nip 50. The further pick up felt 58 picks up the web Wb from an upstream forming section 46 b.
An upstream backing roll 52 co-operates with the suction pressing roll 48 for defining an upstream press nip 54 therebetween. The upstream press nip 54 is disposed upstream relative to the nip 50.
Moreover, a pressing felt 56 extends between the suction pressing roll 48 and the upstream backing roll 52 so that the web Wb is disposed between the pressing felt 56 and the suction pressing roll 48 during passage of the web Wb through the upstream press nip 54.
In operation of the transfer apparatus according to the present invention as shown in FIG. 1, the web W passes through a pressing nip 38 and then passes through a press nip 19. The pressed web W is supported by the transfer blanket 16 until the web is transferred from the transfer blanket 16 to the pressure roll felt 30 by the transfer roll 26 and then onto the Yankee dryer 14 all without any open draw of the web W.
In operation of the arrangement shown in FIG. 2, instead of a transfer roll 26, the pressure roll 28 a which is a suction pressure roll transfers the web Wa without any open draw thereof from the transfer blanket 16 a to the Yankee dryer 14 a by means of a pressure roll felt 30 a. Also, the press nip 19 is an extended nip 22.
In operation of the arrangement shown in FIG. 3, the extended nip 22 b is preceded by a nip 50 which utilises the backing roll 20 b of the extended nip 22 b.
Also, the nip 50 is preceded by an upstream press nip 54. Such upstream press nip 54 may be optional.
The present invention provides a unique transfer apparatus for transferring a light weight web such as tissue from a dewatering section 12 to a Yankee dryer 14 without rewetting the web by a felt extending through the dewatering section.

Claims

1. A transfer apparatus for transferring a light weight web from a dewatering section to a Yankee dryer, said transfer apparatus comprising:

a looped transfer blanket disposed between the dewatering section and the Yankee dryer for supporting and transporting the web from the dewatering section towards the Yankee dryer;

the dewatering section including:

a press defining a press nip for the passage therethrough of the web, said press nip assisting in dewatering the web, said press nip guiding the web;

a press felt extending through said press nip;

said transfer blanket extending through said press nip; and

a roll disposed downstream relative to said press nip for transferring the web from said transfer blanket and for guiding the web towards the Yankee dryer.

2. A transfer apparatus as set forth in claim 1 wherein

said press includes:

a press roll for guiding the web;

a backing roll cooperating with said press roll such that said press roll and said backing roll define therebetween said press nip for the passage therethrough of the web;

said press felt extending through said press nip such that said press felt is disposed between said press roll and the web during passage of said press felt and the web through said press nip;

said transfer blanket extending through said press nip such that said transfer blanket is disposed between said backing roll and the web during passage of said transfer blanket and the web through said press nip.

3. A transfer apparatus as set forth in claim 1 wherein

the dewatering section includes:

an elongate press shoe for guiding the web;

a backing roll co-operating with said press shoe for defining therebetween an extended nip for the passage therethrough of the web;

a press felt extending through said extended nip such that said press felt is disposed between said press shoe and the web during passage of said press felt and the web through said extended nip;

said transfer blanket extending through said extended nip such that said transfer blanket is disposed between said backing roll and the web during passage of said transfer blanket and the web through said extended nip;

a roll disposed downstream relative to said extended nip for transferring the web from said transfer blanket and for guiding the web towards the Yankee dryer.

4. A transfer apparatus as set forth in claim 3 wherein

said looped transfer blanket is impervious to water such that, during transit of the web supported by said transfer blanket between said extended nip and said roll, rewetting of the web is inhibited.

5. A transfer apparatus as set forth in claim 3 wherein

said roll is a transfer roll for transferring the web from said looped transfer blanket;

said transfer apparatus further including:

a pressure roll disposed downstream relative to said transfer roll;

a pressure roll felt extending around said transfer roll and said pressure roll such that when the web is transferred by said transfer roll from said transfer blanket to said pressure roll felt, the web is thereafter guided and supported by said pressure roll felt to and around said pressure roll so that the web is transferred from said pressure roll felt to the Yankee dryer for drying of the web.

6. A transfer apparatus as set forth in claim 5 wherein

said transfer roll is a suction transfer roll.

7. A transfer apparatus as set forth in claim 3 wherein

said roll is a suction pressure roll for transferring the web from said looped transfer blanket;

said transfer apparatus further including:

a pressure roll felt extending around said suction pressure roll such that when the web is transferred by said suction pressure roll from said transfer blanket to said pressure roll felt, the web is thereafter guided and supported by said pressure roll felt around said suction pressure roll so that the web is transferred from said pressure roll felt to the Yankee dryer for drying the web.

8. A transfer apparatus as set forth in claim 3 further including:

a press section disposed upstream relative to said extended nip.

9. A transfer apparatus as set forth in claim 8 wherein

said press section includes:

a pressing roll;

a further backing roll co-operating with said pressing roll for defining therebetween a pressing nip for the passage therethrough of the web.

10. A transfer apparatus as set forth in claim 9 further including:

a pick up felt extending through said pressing nip such that said pick up felt is disposed between said pressing roll and the web during passage of said pick up felt and the web through said pressing nip.

11. A transfer apparatus as set forth in claim 9 further including:

a further press felt extending through said pressing nip such that said further press felt is disposed between said further backing roll and the web during passage of said further press felt and the web through said pressing nip.

12. A transfer apparatus as set forth in claim 11 further including:

a suction roll disposed downstream relative to said pressing nip and upstream relative to said extended nip, said suction roll co-operating with said further press felt for transferring the web from said further press felt to said press felt

13. A transfer apparatus as set forth in claim 12 wherein

the web is disposed between said further press felt and said press felt.

14. A transfer apparatus as set forth in claim 10 wherein

said pick up felt co-operates with a forming section for transferring the web from the forming section to said pick up felt.

15. A transfer apparatus as set forth in claim 3 further including:

a suction press roll co-operating with said backing roll for defusing a nip therebetween, said nip being disposed upstream relative to said extended nip.

16. A transfer apparatus as set forth in claim 15 further including:

a pick up felt extending between said suction pressing roll and said backing roll so that the web is disposed between said pick up felt and said backing roll during passage of the web through said nip, said pick up felt picking up the web from an upstream forming section.

17. A transfer apparatus as set forth in claim 16 further including:

an upstream backing roll co-operating with said suction pressing roll for defining an upstream press nip therebetween, said upstream press nip being disposed upstream relative to said nip.

18. A transfer apparatus as set forth in claim 17 further including:

a pressing felt extending between said upstream backing roll and said suction pressing roll so that the web is disposed between said pressing felt and said upstream backing roll during passage of the web through said upstream press nip.

19. A transfer apparatus for transferring a light weight web from a dewatering section to a Yankee dryer, said transfer apparatus comprising:

the dewatering section including:

an elongate press shoe for guiding the web;

a roll disposed downstream relative to said extended nip for transferring the web from said transfer blanket and for guiding the web towards the Yankee dryer; and

said looped transfer blanket being impervious to water such that during transit of the web supported by said transfer blanket between said extended nip and said roll, rewetting of the web is inhibited.

20. A transfer apparatus for transferring a light weight web from a dewatering section to a Yankee dryer, said transfer apparatus comprising:

the dewatering section including:

an elongate press shoe for guiding the web;

a roll disposed downstream relative to said extended nip for transferring the web from said transfer blanket and for guiding the web towards the Yankee dryer;

said looped transfer blanket being impervious to water such that during transit of the web supported by said transfer blanket between said extended nip and said roll, rewetting of the web is inhibited;

said roll being a transfer roll for transferring the web from said looped transfer blanket;

said transfer apparatus further including:

a pressure roll disposed downstream relative to said transfer roll;

a pressure roll felt extending around said transfer roll and said pressure roll such that when the web is transferred by said transfer roll from said transfer blanket to said pressure roll felt, the web is thereafter guided and supported by said pressure roll felt to and around said pressure roll so that the web is transferred from said pressure roll felt to the Yankee dryer for drying the web;

said transfer roll being a suction transfer roll;

a press section disposed upstream relative to said extended nip;

said press section including:

a pressing roll;

a further backing roll co-operating with said pressing roll for defining therebetween a pressing nip for the passage therethrough of the web;

a pick up felt extending through said pressing nip such that said pick up felt is disposed between said pressing roll and the web during passage of said pick up felt and the web through said pressing nip;

a further press felt extending through said pressing nip such that said further press felt is disposed between said further backing roll and the web during passage of said further press felt and the web through said pressing nip;

a suction roll disposed downstream relative to said pressing nip and upstream relative to said extended nip, said suction roll co-operating with said further press felt for transferring the web from said further press felt to said press felt, the web being disposed between said further press felt and said press felt; and