JPH06116892A - Selvedge cutting nozzle for papermaking machine - Google Patents

Abstract

PURPOSE:To ensure various troubles not to be developed due to paper powder scattering around in cutting a paper stock by blowing out water jet from a water jet nozzle. CONSTITUTION:When a paper stock 2 is to be cut along a cutting line 16 by blowing out pressurized water from a nozzle 3 at the lower end of the center of a central member 8, an outer cylindrical member 9 is equipped around the central member 8 and compressed air is blown out through a slit nozzle 12 between the members 8 and 9 to form an air curtain 13 to block paper powder, thus preventing its scattering.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trimming nozzle for a paper machine for cutting a paper material conveyed on a conveyor into a predetermined paper width.

[0002]

2. Description of the Related Art Generally, a paper machine is composed of a wire part for forming a paper layer on a running paper net, a press part for removing moisture from a wet paper web, and a dryer part. It is made into paper by going through.
As shown in FIG. 3, a conventional edge-cutting device for a paper machine forms a preset paper width in the wire part just before the paper raw material 2 is conveyed to the next press part (felt 20 or later). Then, it is put in a so-called edge-cutting step of cutting the left and right ends of the paper material being conveyed. In the conventional case, when performing the edge-cutting work, the water jet nozzle (edge-cutting nozzle) 3 is used so as to perform edge-cutting at both ends in the width direction above the paper making conveyor 1 in the wire part.
Is arranged, and the both ends of the paper raw material 2 conveyed by the edge cutting nozzle 3 are cut by spraying the jet water 4.

The edge-cutting nozzles 3 are arranged above the paper making conveyor 1 at both left and right ends, and are generally arranged in a number of 4 or more in total of 2 pairs or 3 pairs or more. A plurality of pairs are provided because each one nozzle breaks down or jets out during operation, and the cut paper material 2 bounces off and becomes paper dust 5 that adheres to the nozzle outlet and causes clogging. In case of malfunction, it is possible to immediately jet water with another nozzle instead of stopping the conveyor 1, or
When cutting cannot be performed with one nozzle, the second nozzle is used to cut at the same position. The defective nozzle is replaced with a new nozzle, or paper dust attached to the nozzle is washed with water, and if the water jet is normal, it is used again.

[0004]

Conventionally, as shown in FIG. 3, conventionally, a plurality of pairs of edge-cutting nozzles 3 are arranged, that is, two or more pairs. This is because even if the edge-cutting nozzle 3a or 3b fails in use, the stop of the paper making conveyor 1 is avoided. Further, when a large number of nozzles are arranged along the traveling direction of the paper making conveyor 1, the paper raw material 2 repelled by the water jet of the upstream side nozzle 3a becomes the paper powder 5, and the downstream side nozzle 3b is soiled and cutting failure occurs. It was necessary to regularly clean and replace it in order to cause Further, in recent years, as the speed of the paper machine has been increased, the water pressure and the water amount have been increased, but there has been a problem that these measures cause an increase in nozzle troubles due to the paper dust 5. SUMMARY OF THE INVENTION The present invention provides an edge-cutting nozzle that is unlikely to cause defective cutting due to paper dust, and intends to solve the above-mentioned conventional problems.

[0005]

For this reason, the present invention has a nozzle for ejecting pressure water for cutting wet paper in the central portion, and an air curtain forming slit nozzle around the nozzle. This is a means for solving the problem.

[0006]

When compressed air is ejected from the slit nozzle provided around the nozzle ejecting the pressure water, an air curtain is formed around the nozzle. This air curtain
It is possible to prevent the scattering of the paper powder generated by the paper material bouncing back by the injection of the pressure water from the nozzle, and to prevent the other nozzles disposed downstream of the nozzle from being contaminated.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments of the drawings. FIGS. 1 and 2 show the embodiments of the present invention. In the figure, 7 is a nozzle body, a central member 8 having a pressure guiding pipe 6b in the central portion, and a metric fine screw 14 on the outer peripheral surface of the member 8.
For forming an air curtain that is connected to the compressed air chamber 10 formed between the outer cylinder member 9 and the central member 8 at the outer periphery of the lower cylinder part 9 A slit nozzle 12 is formed, compressed air is supplied to the compressed air chamber 10 through a supply port 11, and the compressed air is ejected from the slit nozzle 12 as an air curtain 13. The size of the nozzle 12 can be made variable in the range of 0.2 to 1.0 mm by preparing various outer cylinder members 9. A conduit 6a into which pressure water is introduced is connected to the upper end of the pressure water guide pipe 6b, and a nozzle 3 for ejecting pressure water for cutting the paper raw material 2 is connected to the lower end thereof.
Are connected by a PT screw 17. Reference numeral 15 is a rotation preventing hole, which is used to attach and detach the outer cylinder member 9 and the nozzle 3 using a dedicated tool. Further, 1 is a paper making conveyor, 4 is water jet, and 16 is a cutting portion of the paper raw material 2.
Note that the ejection angle of the air curtain 13 can be enhanced by selecting an appropriate value depending on the paper type, papermaking conditions, etc.

Next, the operation will be explained.
The paper raw material 2 is hit as the sprayed water 4 through a, the pressure guiding pipe 6b and the nozzle 3, and the paper raw material 2 is cut by the cutting unit 16. In this case, if there is no air curtain as shown in FIG. 4, paper dust 5 is generated as shown in FIG. 3, but if there is an air curtain 13 as shown in FIG. 1, the scattering of paper dust as shown in FIG. 3 is suppressed. Therefore, the trouble of cutting failure due to paper dust is eliminated, and good cutting is possible.

[0009]

As described above in detail, according to the present invention, the compressed air ejected from the slit nozzle forms an air curtain, so that the downstream nozzle is contaminated by paper dust scattering which is one of the causes of troubles in edge cutting. It is also possible to prevent problems such as soiling the nozzle of itself. Further, it is difficult to eliminate the generation of paper dust at all in a high-speed paper machine, but in the present invention, it is possible to prevent paper dust scattering by the air curtain or prevent the invasion of paper dust to prevent cutting defects due to the paper dust. effective.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a trimming nozzle for a paper machine according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a side view of a conventional edge trimming device for a paper machine.

FIG. 4 is a detailed side view of the edge cutting nozzle portion in FIG.

[Explanation of symbols]

 1 Paper Making Conveyor 2 Paper Raw Material 4 Jet Water 5 Paper Powder 6a Conduit 6b Pressure Water Pipe 7 Nozzle Main Body 8 Central Member 9 Outer Cylinder Member 10 Compressed Air Chamber 11 Compressed Air Supply Port 12 Slit Nozzle 13 Air Curtain 14 Meter Fine Screw 15 Around Fixing hole 16 Paper material cutting part 17 PT screw

Claims (1)

[Claims] 1. A trimming nozzle for a paper machine, comprising a nozzle for ejecting pressured water for cutting wet paper in a central portion, and an air curtain forming slit nozzle provided around the nozzle.