Method and a device for removing water from the surface of a roller jacket
View Patent ↗The present invention relates to a method for removing water from a movable roll jacket surface in a wet section of a paper-making machine, which roll jacket surface preferably belongs to a flexible roll jacket in a shoe press, said method comprising the following steps: arranging a spray device next to the roll jacket surface, making available a collecting device which is provided with an opening and collects liquid, moving said roll jacket surface past said spray device, applying a medium onto said roll jacket surface with the aid of said spray device, and collecting liquid in said liquid-collecting device. The invention is characterized in that said medium is sprayed with high kinetic energy onto said roll jacket surface to follow a fluid stream rebounding from the roll jacket surface, so that the liquid is conveyed to said liquid-collecting device.
1. A method of removing water from a surface of a flexible rotatable roll jacket of a shoe press roll in a shoe press unit in a wet section of a paper-making machine, the shoe press unit including a counter roll cooperating with the shoe press roll to form an extended press nip for pressing water from a wet fiber web transported thererthrough by a press felt forming a loop about the shoe press roll, the shoe press roll rotating in a direction of travel so as to advance the press felt and the wet fiber web through the extended press nip, said method comprising:
directing a spray of a liquid medium from a spray device, disposed within the loop and adjacent to the shoe press roll, toward the roll jacket surface and at least partially against the direction of travel of the shoe press roll, the spray being configured such that the liquid medium contacts the roll jacket surface, collects any water pressed from the wet fiber web remaining on the roll jacket surface, and then rebounds from the roll jacket surface; and
collecting the rebounded liquid medium and water from the roll jacket surface with a liquid-receiving device disposed adjacent to and upstream, with respect to the direction of travel of the shoe press roll, of the spray device, the liquid-receiving device having a lip element operably engaged therewith and capable of being extended therefrom toward the roll jacket surface so as to direct the rebounded liquid medium and water from the roll jacket surface toward the liquid-receiving device.
2. A method according to claim 1 wherein directing a spray further comprises directing a spray toward the roll jacket surface, at least partially against the direction of travel of the shoe press roll, at an angle of between about 5 degrees and about 85 degrees with respect to a normal of the roll jacket surface.
3. A method according to claim 1 wherein the shoe press roll is rotated at a rotational speed and wherein directing a spray further comprises directing a spray toward the roll jacket surface at an angle, with respect to a normal of the roll jacket surface and at least partially against the direction of travel of the shoe press roll, the angle corresponding to the rotational speed.
4. A method according to claim 3 wherein directing a spray further comprises increasing the angle of the spray as the rotational speed increases.
5. A method according to claim 1 wherein the liquid medium and the water from the roll jacket surface rebound from the roll jacket surface in a direction corresponding to an angle at which the spray is directed toward the roll jacket and the method further comprises redirecting the rebounded liquid medium and water to the liquid-receiving device with the lip element.
6. A method according to claim 5 further comprising adjusting the distance from the lip element to the roll jacket surface.
7. A method according to claim 1 wherein directing a spray further comprises rotating a pipe having at least one spray nozzle fixed thereto, the pipe and the at least one spray nozzle comprising the spray device, so as to direct the spray toward the roll jacket surface.
8. A method according to claim 1 wherein the liquid-receiving device is configured to collect the rebounded liquid medium and water from the roll jacket surface through an opening defined thereby and the method further comprises establishing a pressure within the liquid-receiving device and inside the opening lower than a pressure external to the liquid-receiving device and outside the opening so as to provide a suction for collect the rebounded liquid medium and water.
9. A method according to claim 8 further comprising varying a dimension of the opening.
10. A method according to claim 1 wherein the liquid medium comprises water and directing a spray further comprises directing a spray of water from the spray device toward the roll jacket surface.
11. A method according to claim 1 wherein directing a spray further comprises directing the liquid medium into an elongate pipe, defining a longitudinal axis and arranged substantially parallel to the shoe press roll, and through a plurality of spray nozzles arranged longitudinally along the pipe toward the roll jacket surface.
12. A method according to claim 11 wherein each spray nozzle defines a mouth configured to produce a spray oriented along a jet line and directing the medium further comprises directing the medium through the plurality of spray nozzles, each arranged such that the jet line thereof is disposed at an acute angle with respect to the longitudinal axis of the pipe, toward the roll jacket surface.
13. A method according to claim 11 wherein each spray nozzle defines a month configured to produce a spray oriented along a jet line and directing the medium further comprises directing the medium through the plurality of spray nozzles, each arranged such that the jet line thereof is disposed at an angle of between about 3 degrees and about 30 degrees with respect to the longitudinal axis of the pipe, toward the roll jacket surface.
14. A device adapted to remove water from a surface of a flexible rotatable roll jacket of a shoe press roll in a shoe press unit in a wet section of a paper-making machine, the shoe press unit including a counter roll cooperating with the shoe press roll to form an extended press nip for pressing water from a wet fiber web transported therethrough by a press felt forming a loop about the shoe press roll, the shoe press roll rotating in a direction of travel so as to advance the press felt and the wet fiber web through the extended press nip, said device comprising:
a spray device disposed within the loop and adjacent to the shoe press roll, the spray device being configured to direct a spray of a liquid medium toward the roll jacket surface and at least partially against the direction of travel of the shoe press roll, the spray being configured such that the liquid medium contacts the roll jacket surface, collects any water pressed from the wet fiber web remaining on the roll jacket surface, and then rebounds from the roll jacket surface; and
a liquid-receiving device disposed adjacent to and upstream, with respect to the direction of travel of the shoe press roll, of the spray device and having a lip element operably engaged therewith and capable of being extended therefrom toward the roll jacket surface so as to direct the rebounded liquid medium and water from the roll jacket surface toward the liquid-receiving device.
15. A device according to claim 14 wherein the spray device is further configured to direct the spray toward the roll jacket surface, at least partially against the direction of travel of the shoe press roll, at an angle of between about 5 degrees and about 85 degrees with respect to a normal of the roll jacket surface.
16. A device according to claim 14 wherein the shoe press roll is rotated at a rotational speed and wherein the spray device is further configured to direct the spray toward the roll jacket surface at an angle, with respect to a normal of the roll jacket surface and at least partially against the direction of travel of the shoe press roll, corresponding to the rotational speed, the angle of the spray increasing as the rotational speed increases.
17. A device according to claim 14 wherein the lip element is movable with respect to the liquid-receiving device such that the distance from the lip element to the roll jacket surface is adjustable.
18. A device according to claim 14 wherein the spray device further comprises a pipe having at least one spray nozzle fixed thereto, the pipe being rotatable so as to move the at least one spray nozzle to direct the spray toward the roll jacket surface.
19. A device according to claim 14 wherein the liquid-receiving device is configured to collect the rebounded liquid medium and water from the roll jacket surface through an opening defined thereby, the opening extending longitudinally in opposing relation to the roll jacket surface.
20. A device according to claim 19 wherein the liquid-receiving device further comprises a container operably engaged with the opening, the container having a suction applied thereto through an outlet, whereby the applied suction extends through the opening for collecting the rebounded liquid medium and water.
21. A device according to claim 19 wherein the opening of the liquid-receiving device is configured such that a dimension of the opening is capable of being varied.
22. A device according to claim 14 wherein the liquid medium further comprises water.
23. A device according to claim 14 wherein the spray device further comprises an elongate pipe, defining a longitudinal axis and arranged substantially parallel to the shoe press roll, and a plurality of spray nozzles arranged longitudinally along the pipe, the liquid medium being received by the pipe and discharged toward the roll jacket surface through the spray nozzles.
24. A device according to claim 23 wherein each spray nozzle defines a mouth configured to produce a spray oriented along a jet line and each spray nozzle is arranged such that the jet line thereof is disposed at an angle of between about 3 degrees and about 30 degrees with respect to the longitudinal axis of the pipe.
25. A press section of a paper-making machine, comprising:
a shoe press unit including a shoe press roll having a flexible rotatable roll jacket and a counter roll cooperating with the shoe press roll to form an extended press nip adapted to press water from a wet fiber web transported therethrough by a press felt forming a loop about the shoe press roll, the shoe press roll rotating in a direction of travel so as to advance the press felt and die wet fiber web through the extended press nip; and
a device disposed within the loop and adapted to remove water from a surface of the roll jacket, the device comprising:
a spray device dispose adjacent to the shoe press roll, the spray device being configured to direct a spray of a liquid medium toward the roll jacket surface and at least partially against the direction of travel of the shoe press roll, the spray being configured such that the liquid medium contacts the roll jacket surface, collects any water pressed from the wet fiber web remaining on the roll jacket surface, and then rebounds from the roll jacket surface; and
a liquid-receiving device disposed adjacent to and upstream, with respect to the direction of travel of the shoe press roll, of the spray device and having a lip element operably engaged therewith and capable being extended therefrom toward the roll jacket surface so as to direct the rebounded liquid medium and water from the roll jacket surface toward the liquid-receiving device.
26. A press section according to claim 25 wherein the spray device is further configured to direct the spray toward the roll jacket surface, at least partially against the direction of travel of the shoe press roll, at an angle of between about 5 degrees and about 85 degrees with respect to a normal of the roll jacket surface.
27. A press section according to claim 25 wherein the shoe press roll is rotated at a rotational speed and wherein the spray device is further configured to direct the spray toward the roll jacket surface at an angle, with respect to a normal of the roll jacket surface and at least partially against the direction of travel of the shoe press roll, corresponding to the rotational speed, the angle of the spray increasing as the rotational speed increases.
28. A press section according to claim 25 wherein the lip element is movable with respect to the liquid-receiving device such that the distance from the lip element to the roll jacket surface is adjustable.
29. A press section according to claim 25 wherein the spray device further comprises a pipe having least one spray nozzle fixed thereto, the pipe being rotatable so as to move the at least one spray nozzle to direct the spray toward the roll jacket surface.
30. A press section according to claim 25 wherein the liquid-receiving device is configured to collect the rebounded liquid medium and water from the roll jacket surface through an opening defined thereby, the opening extending longitudinally in opposing relation to the roll jacket surface.
31. A press section according to claim 30 wherein the liquid-receiving device further comprises a container operably engaged with the opening, the container having a suction applied thereto through an outlet, whereby the applied suction extends through the opening for collecting the rebounded liquid medium and water.
32. A press section according to claim 30 wherein the opening of the liquid-receiving device is configured such that a dimension of the opening is capable of being varied.
33. A press section according to claim 25 wherein the liquid medium further comprises water.
34. A press section according to claim 25 wherein the spray device further comprises an elongate pipe, defining a longitudinal axis and arranged substantially parallel to the shoe press roll, and a plurality of spray nozzles arranged longitudinally along the pipe, the liquid medium being received by the pipe and discharged toward the roll jacket surface through the spray nozzles.
35. A press section according to claim 34 wherein each spray nozzle defines a mouth configured to produce a spray oriented along a jet line and each spray nozzle is arranged such that the jet line thereof is disposed at an angle of between about 3 degrees and about 30 degrees with respect to the longitudinal axis of the pipe.