JPH0559684A - Drier for paper-making machine - Google Patents

Abstract

PURPOSE:To dispense with a linear part between a suction box and a drier roll and prevent the fluttering of wet paper by placing an inlet-side and an outlet-side suction boxes in addition to a return suction box on a canvas- supporting apparatus. CONSTITUTION:An inlet-side and an outlet-side suction boxes 13, 13 are placed in addition to a return suction box 12 on a canvas-supporting apparatus in such a manner as to be freely separable from a canvas 2. The suction boxes are made to contact with the canvas during operation to eliminate the free-part of the canvas. The suction boxes are separated from the canvas in the case of passing the joint part of the canvas or a foreign materials.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a paper machine dryer.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional single-canvas dryer. The dryer is composed of a plurality of dryer rolls 11 (11a, 11b, ... 11f) and a suction return roll 17 (17a, 17b, ... 17).
f) and one canvas 2 (2a, 2b, ... 2)
f), the wet paper web 1 is supported by the canvas 2 and heated by the dryer roll 11 as shown in FIG. 6, and then sucked and held by the suction return roll 17 to circulate. It is designed to face the next dryer roll 11.

[0003]

Since the wet paper 1 which has not been dried has a low strength, it is held on a canvas and conveyed, but the wet paper may be cut. Suction return to remove the cut wet paper 1 (hereinafter referred to as broke), to avoid the risk of the wet paper 1 getting wrapped around the dryer roll 11, and to pass the seam of the canvas 2 and other foreign matter. Roll 1
7 is set apart from the dryer roll 11 by several tens of mm (a dimension). Therefore, between the tangent line of the dryer roll 11 and the suction return roll 17, several hundred mm (a dimension)
There is no choice but to provide a straight section. Ideally, the dryer roll 11 should be wrapped with a contact angle that is as large as possible and that the wet paper should be held completely while running, but this linear portion has the drawback that a large wrap angle cannot be taken for the dryer roll. there were. Further, since the sheet is not completely held in the straight portion, there are problems such as the risk of flapping and cutting of the wet paper, the dimensional stability of the finished paper due to restraint drying, and the effect of increasing the bending rigidity.

In the present invention, the canvas run length does not change during operation and stop, and during operation, all parts except the part held by the dryer roll on the canvas are held by vacuum suction. In addition, during the broking process, a gap for processing can be opened, and in order to escape foreign matter in case of emergency, the fixing device close to the roll does not provide a paper machine dryer with weak elastic support etc. It is what

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention provides a single canvas type paper machine dryer for alternately drying and transporting canvas and wet paper by a plurality of dryer rolls and a plurality of canvas supporting devices. The device has a return suction box which has a large number of suction holes on the surface in contact with the canvas and which changes the traveling direction of the canvas, and the canvas which travels between the return suction box and the inlet dryer roll and the outlet dryer roll, This is composed of an inlet side suction box and an outlet side suction box provided with a large number of suction holes on the contact surface so as to be freely separable, and this is a means for solving the problem.

[0006]

[Function] During operation, the inlet and outlet suction boxes are wound around the dryer rolls and moved forward so as to come into contact with the running canvas, so that there is no free part of the canvas. Holds the paper by suction. Also, when a seam or a foreign object of the canvas comes, the suction box is retracted so as to be separated from the canvas. In this way, the suction box is placed so that it can come into contact with and separate from the canvas, so there is no need to install the suction box away from the dryer roll.
Since it is not necessary to provide a straight part of the canvas between the two,
The wrap angle of the canvas to the dryer roll becomes large, and the risk of flapping and cutting of wet paper can be prevented.

[0007]

Embodiments of the present invention will now be described with reference to the drawings. FIGS. 1 to 4 show an embodiment of the present invention, FIG. 1 is a side view showing a canvas 2 and a seat run during operation, and FIG. The canvas run at the time of processing and canvas 2 exchange is shown. In the figure, 11 is a dryer roll, 12 is a return suction box, and 13 in FIG. 3 is the shaft 1 of the suction roll 14.
An inlet or outlet suction box rotatably supported by 4a,
Reference numeral 15 is a fixed suction box, 16 is a drive cylinder whose base is attached to the fixed suction box 15, and the rod tip is attached to the suction box 13, respectively. The suction box 13 advances about the shaft 14a by the operation of the cylinder 16. , Is ready to retreat. Both ends of the suction roll 14 are supported by the side surfaces of the fixed suction box 15, and a large number of holes 14b are provided in the cell.

The paper machine dryer according to the embodiment of the present invention is a single canvas type dryer in which a plurality of dryer rolls 11 and a plurality of canvas 2 supporting devices alternately dry and convey the canvas 2 and the wet paper 1. A paper machine dryer, in which a canvas support device has a large number of suction holes on the surface in contact with the canvas 2, and a return suction box 12 for changing the traveling direction of the canvas 2; the return suction box 12; the inlet dryer roll and the outlet side. It is composed of an inlet-side and outlet-side suction box 13 which comes into contact with the canvas 2 running between the dryer roll 11 and the roller 2 so as to be freely separable and which has a large number of suction holes 14b on the contact surface. Further, as shown in FIG. 3, the return suction box 12 is composed of two suction rolls 14 and 14 each having a large number of suction holes 14b on the circumferential surface, and a fixed suction box 15 that supports the same. Further, the inlet side or outlet side suction box 13, the suction roll 14, and the fixed suction box 15 constitute one box in terms of vacuum suction,
The fixed suction box 15 is operated or suction is performed by a vacuum pump connected to an exhaust port (not shown) provided on the drive side. Although the suction roll 14 is a porous roll in the illustrated case, it may be a roll having a circumferential groove on the surface. FIG. 4 is a side sectional view showing a return suction box 12 of an embodiment different from FIG. 3, and has a structure in which a suction roll and a fixed suction box 15 are integrated.

The operation will be described below. FIG. 1 shows a canvas 2 and a sheet run during operation, and FIG. 2 shows a sheet run at the time of broking and when the canvas 2 is replaced. Then, during operation, the drive cylinder 16 is arranged so as to remove the free portion of the canvas 2 so as to hold the wet paper web 1 by suction, and in the unlikely event that a foreign matter comes, the drive cylinder 1
6, the inlet and outlet suction boxes 13 rotate around the shaft 14a to retreat and allow foreign matter to pass therethrough.
Further, during the stop work, the suction box 13 is retracted by retracting the rod of the drive cylinder 16 so as to obtain a sufficient gap with the dryer roll 11. The canvas run is determined only by the fixed suction box 15 in the return suction box 12, and the canvas run does not change.

[0010]

As described above in detail, according to the present invention, during operation, the inlet and outlet suction boxes are in contact with the traveling canvas wound around the inlet and outlet dryer rolls and the canvas is free. By eliminating the parts,
It is possible to prevent cutting of the wet paper. The suction box can be retracted away from the canvas surface of the dryer roll when it is necessary to allow the seams of the canvas or foreign matter to pass through. Therefore, it is not necessary to install the suction box away from the dryer roll as in the past, and it is not necessary to provide a straight part of the canvas between the two, so the wrap angle of the canvas to the dryer roll can be made large, and the wet paper web The risk of flapping and cutting can be prevented.

[Brief description of drawings]

FIG. 1 is a side view showing a running canvas and sheet run of a paper machine dryer according to an embodiment of the present invention.

FIG. 2 is a side view showing a canvas run at the time of broke processing and at the time of canvas replacement according to the embodiment of the present invention.

FIG. 3 is a detailed side sectional view of the return suction box in FIG.

FIG. 4 is a side sectional view of a return suction box showing an embodiment different from FIG.

FIG. 5 is a side view of an all single canvas dryer in a conventional paper machine.

FIG. 6 is a detailed cross-sectional view of a main part in FIG.

[Explanation of symbols]

 1 Wet Paper 2 Canvas 11 Dryer Roll 12 Return Suction Box 13 Inlet or Outlet Suction Box 14 Suction Roll 14a Shaft 14b Suction Hole 15 Fixed Suction Box 16 Drive Cylinder

Claims (1)

[Claims] 1. A single-canvas-type paper machine dryer for alternately drying and transporting canvas and wet paper by a plurality of dryer rolls and a plurality of canvas supporting devices, wherein the canvas supporting device has a large number of surfaces on the surface in contact with the canvas. A return suction box having suction holes for changing the traveling direction of the canvas and a canvas traveling between the return suction box and the inlet side dryer roll and the outlet side dryer roll are contacted with and separable from each other, and a contact surface A paper machine dryer, characterized in that it comprises an inlet side and an outlet side suction box provided with a large number of suction holes.