JPH02191790A - Drying method for web - Google Patents

Abstract

PURPOSE:To provide the title drying method intended to prevent web fluttering and development of wrinkles or paper cuts on a web, so designed that canvas guide rolls at the lower tier of dryer part are made movable and an air stream deflector is installed nearby. CONSTITUTION:Drum dryers 1-3 and guide rolls are alternately arranged and canvases are bridged on this system in a zigzag manner, the resultant system being set up in upper and lower tiers, and a wet paper 9 is bridged in a zigzag manner on the upper and lower drum dryers 1-3 and allowed to travel, thus accomplishing the objective drying. In this drying system, the canvases 6, 7 at the lower tier are bridged in such a way as to be divided into two or more portions, and furthermore, the guide roller 5 guiding the canvas 6 is made movable to enable said canvas 6 to come near the other canvas 7. In addition, a deflector 8 for air stream is installed near the surface of the canvas 7 to prevent air from flowing in between the canvases 6 and 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [A.] Industrial Application Field The present invention relates to a method for drying a wet paper web by providing an air sealing means in a dryer part for drying a running web in a paper manufacturing process.

[B] Conventional technology Conventionally, dryer devices used in paper manufacturing processes include a plurality of drum dryers arranged horizontally in two stages (upper and lower) or in a staggered pattern.
The canvas is attached to the upper drum dryer group and the upper canvas roll group, and similarly the canvas is attached to the lower drum dryer group and the lower canvas roll group, and the web transferred from the wet part to the dry part is covered with canvas. While being guided by the upper and lower drums, the dryer runs alternately along the circumferential surface of the ear and is dried. Each canvas roll was fixed, and the canvas intervals between each dryer part group were left open for waste paper discharge.

[C1 Problem to be solved by the invention However, as recent paper machines have become wider and faster, the amount of air drawn in between each dryer part group has increased.
Oven drying of the web between the dryer groups caused flapping of some webs, contributing to paper wrinkles and paper breakage phenomena.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for eliminating paper wrinkles and paper breakage caused by flapping of some webs during open draw between each group of dryers.

[D] Means for Solving the Problems The present invention makes it possible to move one of the canvas rolls for lower canvas between each group of dryer parts in a paper machine, adjusts the distance between the canvas rolls of the next group, and This method of drying a web is characterized in that a deflector is provided on the outside of a group of canvases to block air from flowing between the canvases.

[E] Operation: The movable guide roller narrows the distance between the canvases, and the deflector blocks the inflow of air, eliminating some of the negative effects of open draw between the dryers, thereby achieving the object of the present invention.

[F] Example Embodiments of the present invention will be described based on the drawings.

FIG. 1 is a schematic side view showing one embodiment of the present invention.
．． 2.3 is a drum dryer arranged in a staggered manner, 4 is a fixed canvas roll, 5 is a movable canvas roll installed in each drum dryer group, and 6 is a canvas guided by the canvas roll 4.5. and travels along the circumferential surface of the drum dryer 2. 7 is a canvas of the next group of drum dryers; like the canvas 6, it is guided by a canvas roll 4.5 and runs along the circumferential surface of the drum dryer 3.

During normal operation, the canvas roll 5 is moved forward to narrow the gap between the canvas 6 and the canvas roll, reducing the amount of air drawn in from the front group drum dryer, and discharging waste paper such as paper cutting and paper cuts. Sometimes, the canvas roll 5 is moved backward to increase the interval between canvases and facilitate the discharge of waste paper.

As a drive device for moving the canvas roll 5, a well-known device such as an air cylinder, a hydraulic cylinder, or an electric cylinder can be used, and as a moving method, a horizontal movement type, a diagonal movement type, a rotation movement type, etc. can be used as appropriate. good.

The approach position of the canvas roll 5 is not effective if it is too far from the next group of canvas rolls, and if it is too close, the seams of the canvas will come into contact with each other and damage the canvas, so it is preferable (not 7, but the distance between the canvases is about 10 to 30 m5) It is preferable that the deflector 8 is installed on the outside of the canvas cover at the top of the canvas roll 5 to block the inflow of air, and is released when paper waste is ejected during paper cutting, paper cuts, etc., and is used to approach the canvas cover during normal operation. The releasing means may be a known method, for example, a crank mechanism using an air cylinder or the like.

Next, to explain the drying method of the present invention using the dryer device described in Section 2, the web 9 transferred from the wet bar is coated on the peripheral surface of each drum dryer 2.1.3 under -L with a canvas 6.1. The canvas rolls 5 and 7 are pressed and dried by running along the dotted lines while being in direct contact with each other.During papermaking, the canvas roll 5 is moved backwards by a drive device to increase the gap between the canvases 6 and 7 and to discharge waste paper. 5. When the normal state is reached, move the canvas roll 5 forward and move the canvas roll 5 forward. (6. Narrow the gap between 7 and move the differential lever 8 from the open state to the closed state. By blocking the inflow of the knee 1, it is possible to prevent a part of the oven from flapping.

When the paper runs out, the waste paper can be easily discharged if the conditions are the same as when paper was cut out.

A web with a basis weight of 40 g/d after drying was machined at a speed of 1000 m/d.
The distance between the canvases 6 and 7 was set to 201, and the deflector 8 was closed to dry. For comparison, the results when only the canvas roll 5 was moved forward and when only the deflector 8 was closed are shown in Table 1.

*○: Very effective in improving sheet running properties.

△: Although the effect is recognized, it is not at a satisfactory level.

As is clear from Table 1, when only the canvas roll 5 is advanced, the amount of air involved is reduced, but the flapping of the web, paper wrinkles, and paper breaks are not eliminated, and the expected air sealing effect is not achieved. - If only the canvas roll 5 is used, there is no reduction in the amount of air entrained, there is only a slight change in the wind direction, and as with the use of only the canvas roll 5, the flapping of the web, paper wrinkles, and paper breaks are not eliminated, and the effect is small.

In the case of the present invention, the amount of air entrained is reduced, and the direction of the slightly entrained air is controlled by a deflector, and there is no flapping of the web, paper wrinkles, or paper breaks in the open draw part, and a good air sealing effect is achieved. be.

[G] Detailed Description of the Invention According to the present invention, it is possible to prevent air from being entrained between each group of dry parts, eliminate flapping that occurs in a part of the web in an open drawer, and eliminate wrinkles and wrinkles on the paper surface. This has the effect of preventing paper cuts between groups.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a dryer device used in the present invention. 1.2.3...Drum dryer 4...
・Canvas roll, 5...Moving canvas roll, 6.7.10・
... Canvas, 8 ... Deflector 9 ... Web,

Claims (1)

[Claims] One of the canvas rolls for the lower canvas between each group of the dryer part of the paper machine is movable, and the distance between the canvases of the next group is adjusted.Furthermore, a deflector is provided outside the canvas of the next group, so that the canvas roll between the canvases can be moved. A web drying method characterized by blocking air inflow.