JPS5912795B2 - Method for preventing dirt from adhering to suction boxes for paper machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing dirt such as pitch from adhering to a suction box, which is a hindrance to paper making. A washing liquid transport pipe is installed in the longitudinal direction (width direction of the paper machine),
A washing liquid supply pipe communicating with this and having slits or many small holes in the upper part is provided, and during paper making, the washing liquid sent through the washing liquid transport pipe is guided to the washing liquid supply pipe, and the slits or small holes The present invention relates to a method for preventing dirt from adhering to a suction box for a paper machine, characterized by gradually and continuously extruding dirt toward the surface and constantly washing the rear end of the lip portion of the upper edge.

Many suction boxes are used in paper machines as a means of removing large amounts of water from wet paper and felt, but sticky substances such as pitch and free size contained in the stock liquid are Some of it sticks to the felt and some of it sticks to the suction box.

Adhesion to the suction box occurs mostly at the rear end of the upper lip.

At first, these sticky substances gradually adhere and become laminated.
Inert substances such as clay, titanium, and talc, hair-removed fibers from felt, fine pulp fibers, resins added to paper stock, etc. are captured by this, and when these dirt deposits grow large, they fall off, causing damage to felt and paper making. This often causes operational problems such as machine damage.

If pulp with a high pitch or deinked pulp is used as raw material in a high-speed newsprint machine, dirt deposits will grow quickly and cause more trouble, so the paper machine must be stopped occasionally to remove them. As a result, operational efficiency is significantly reduced, resulting in a large economic loss.

The present invention is a method for preventing the dirt from adhering to the lip portion of the upper edge, and will be explained below with reference to the drawings.

FIGS. 1 and 2 show a conventional suction box 1 used in papermaking, in which waste water sucked from a felt 2 enters a suction surface 3, passes through a suction tube 4, and is sucked into a suction pump (not shown).

At this time, the dirt substances contained in the waste water that has passed through the felt tread adheres as dirt deposits 7 to the rear end of the lip portion 6 of the upper edge 5 of the suction box in the felt traveling direction (arrow).

3 and 4 show a suction box 1 used in the method of the present invention, in which a cleaning liquid transport pipe 8 is installed inside the upper edge 5 of the suction surface 3.
In communication with this, a cleaning liquid supply pipe 9 is provided inside the lip part 6 of the upper edge, and the cleaning liquid supply pipe has a slit 10 at its upper part as shown in FIG. 7 or a large number of slits 10 as shown in FIG. Small hole 11
have.

5 and 6 show another embodiment of the suction box 1 used in the method of the present invention, in which a cleaning liquid supply pipe 8 and a cleaning liquid supply pipe 9 communicating therewith are provided adjacent to the outside of the upper edge 5. The cleaning liquid supply pipe has a slit 10 or a large number of small holes 11 as in the previous embodiment.

In the above embodiment, the cleaning liquid transport pipe 8 and the cleaning liquid supply pipe 9 are
Although it is provided on the rear upper edge in the felt traveling direction, it can also be provided on the front upper edge, or on both upper edges.

The position and suction method for installing such a suction box in a paper machine may be the same as in the past, but at the same time as papermaking starts or as necessary, a pump (for pumping) washing liquid from a washing liquid tank (not shown) may be used. (not shown), the cleaning liquid is fed through the cleaning liquid transport pipe 8, and further press-fitted into the cleaning liquid supply pipe 9, and the slit 10
Or gradually and continuously extrude it from the small hole 11.

Since the rear end of the lip 6 is constantly washed with this cleaning liquid, it is always kept clean and free of dirt and deposits.

As the washing liquid, a dilute solution of nonionic activator, high alcohol detergent, etc., a solvent or a mixed solution of these, or a weakly acidic solution in which an acid is added to these are used.If the washing liquid is used from the beginning of papermaking, clean water is used. Or even warm water is effective.

As described above, according to the method of the present invention, dirt substances contained in papermaking waste water do not adhere to the lip of the upper edge of the suction box, so no trouble occurs during papermaking, and furthermore, in order to remove dirt deposits, Since there is no need to stop the paper machine, the operating rate can be greatly improved.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view in the width direction of a suction box used for conventional paper making, Fig. 2 is a longitudinal sectional view of the A-A section thereof, and Fig. 3 is a longitudinal sectional view in the width direction of a suction box used in the method of the present invention. 4 is a longitudinal sectional view of the section B-B, FIG. 5 is a longitudinal sectional view of the suction box in the width direction of another embodiment, and FIG. 6 is a longitudinal sectional view of the section C-C. FIG. 7 is a plan view of the cleaning liquid supply pipe, and FIG. 8 is a plan view of another embodiment thereof. In the figure, 1 is a suction box, 2 is a felt, and 3 is a suction box.
is a suction surface, 4 is a suction tube, 5 is an upper edge, 6 is a lip, 7 is a dirt deposit, 8 is a cleaning liquid transport pipe, 9 is a cleaning liquid supply pipe, 10
is a slit, and 11 is a small hole.

Claims (1)

[Claims] 1. A suction box is placed inside the upper edge of the suction box, or adjacent to the outside in the longitudinal direction (width direction of the paper machine), communicates with the washing liquid transport pipe, and has slits or many small holes in the upper part. During paper making, the washing liquid sent through the washing liquid transport pipe is guided to the washing liquid supply pipe, and is gradually and continuously pushed out to the surface through the slit or small hole, and the washing liquid is gradually and continuously pushed out to the surface through the slit or small hole. A method for preventing dirt from adhering to a suction box for a paper machine, characterized by constantly washing the rear end of the paper machine.