JPH0329357Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a selvage nozzle for a paper making machine for cutting paper raw material conveyed on a conveyor into a predetermined paper width.

[Conventional technology]

In general, a paper making machine consists of a wire part that forms a paper layer on a running gauze, a press part that removes moisture from wet paper, and a dryer part, and paper passes through a series of these processes in sequence. It is made by papermaking.

At that time, in the wire part, just before the wet paper is conveyed to the next press part,
The wet paper web being conveyed is subjected to a so-called edge cutting process in which the left and right ends are cut to form a preset paper width.

Conventionally, when carrying out the above-mentioned edge-cutting work, water jet nozzles for edge-cutting were installed at both ends in the width direction above the screen conveyor in the wire part, and the wet paper being conveyed was Both ends are cut by jetting high-pressure water.

Here, the selvage nozzles are generally arranged above the plow net conveyor in a pair, one on each end on the left and right sides, or in two or more pairs, for a total of four or more. The reason for arranging the plurality of pairs is that if one nozzle malfunctions during operation or the paper material that is cut by spraying rebounds and adheres to the nozzle nozzle,
This is to enable water to be immediately injected from another nozzle in place of the conveyor without stopping the conveyor if the conveyor becomes inoperable due to clogging or the like.

[The problem that the idea attempts to solve]

By the way, the conventional selvedge nozzle has a nozzle body formed with one water inlet and one large-diameter water conduit communicating with the nozzle body, and a high-pressure water inlet that is attached to the tip of the nozzle body through a cap. It is composed of three parts: a nozzle chip with one small-diameter nozzle for spouting, and the water conduit and the nozzle that communicates with it are both formed of a single piece and spray a single stream of high-pressure water. It's becoming like that.

Therefore, as mentioned above, if one of the pair of ear-cut nozzles in operation becomes unable to spray high-pressure water due to failure or clogging, for example, if only one pair of ear-cut nozzles is installed, , it becomes impossible to cut the paper to the specified width, so the running of the screen conveyor is temporarily stopped and the edge cutting nozzle is repaired.
It will be necessary to carry out work such as replacement.

Therefore, by arranging two or more pairs of selvage nozzles along the running direction at both upper ends of the plow net conveyor, even if the selvage nozzles in use become inoperable, the conveyor However, since a plurality of edge cutting nozzles must be arranged side by side along the running direction of the conveyor, space is required.
Therefore, when attempting to arrange a large number of devices, it is necessary to change the design of the entire machine, which is either impossible or limits the number of devices that can be arranged in parallel.

Furthermore, in recent years, as the speed of paper making machines has increased, the running speed of the filter net has increased, so the power and water volume of the injection pressure of a single hole cannot cope with the increase in speed.
Paper cut defects occurred, which caused various problems. However, it is impossible to cut paper simply by expanding the diameter of the nozzle hole and increasing the amount of water. In other words, when cutting a running wet paper web using water jet, even if a predetermined jetting pressure is set, it will not be possible to simply spray one line of water at each end of the wet paper web with a single pair of nozzles. When the screen conveyor runs at high speed, the cut edge of the paper cannot be straight, and jagged irregularities occur along the running direction of the paper.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide a selvage nozzle that can cut wet paper web continuously, is less likely to cause poor cutting, and can be used in a small space.

[Means to achieve the purpose]

In order to achieve the above object, the edge cutting nozzle for a paper making machine of the present invention is a edge cutting nozzle for a paper making machine that cuts edges of paper raw material being conveyed by a pressure jet of water, and has a single nozzle body. The nozzle is characterized by comprising two water conduits with the same large diameter that pass through the interior of the nozzle body independently of each other, and two nozzles with the same small diameter formed at the centers of the tips of each of the water conduits.

[Effect]

According to the present invention, two water conduits are formed independently inside one nozzle body, and the two water channels are formed independently.
At the tips of the two waterways, there are two waterways that communicate with each of the waterways and have a diameter smaller than that of the waterway.
Since two nozzles are drilled at a predetermined interval, two lines of high pressure are emitted from the two nozzles through each water conduit from the two independently provided water inlets. Water will be sprayed.

Therefore, these two stripes of high-pressure water are sprayed at the upstream and downstream positions corresponding to the predetermined width for cutting the wet paper, so even if the water sprayed on the upstream side cuts the paper, Even if cutting defects occur,
Since the defective cutting portion can be removed by jetting water on the downstream side, paper having smooth straight edges can be made using a single nozzle.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show an entire embodiment of a selvage nozzle 1 of the present invention, and this selvage nozzle 1 has two notches 1a around a nozzle body 2 for engagement with a wrench. For example, the total length A of the nozzle is 44 mm, the maximum external diameter B is 17 mm, and the diameter C of the water inlet 3 and the water conduit 4 communicating with it is 4.5 mm, and the nozzle is further formed on the tip side. The diameter D of the nozzle 5 is set to 0.3 to 1.0 mm.

Here, the water inlet 3 and the water conduit 4 communicating therewith are located inside the nozzle body 2 along the axial direction.
Two of each are formed independently, and furthermore, the nozzles 5, 5 at the tip of the nozzle are also spaced apart from each other by a predetermined interval and communicate with each of the water conduits 4, 4, respectively.
Two nozzles are formed, and the diameters of these nozzles 5, 5 are formed to be extremely small compared to the diameters of the water conduits 4, 4 in order to spout high-pressure water.

Specifically, as shown in FIG. 4, the edge-cutting nozzle 1 includes a disk-shaped nozzle tip 6 fitted to the tip of a nozzle body 2, and a nozzle tip 6.
As mentioned above, the inside of the nozzle body 2 is penetrated by two independent large-diameter conduits 4, and the very small-diameter two formed in the nozzle tip 6 pass through the interior of the nozzle body 2. Two spout ports 5 are fixed so as to communicate with the two water conduits 4.

Here, the reason why two water inlet ports 3 of the nozzle body 2 and two water conduits 4 communicating therewith are formed independently is to equalize the respective water pressures ejected from the two nozzle ports 5. In other words, as a result of the inventor's experiments, it has been found that if only two spout ports 5 and a single water inlet port 3 and water conduit 4 are formed, both the spout ports 5 and 5
This is because it has been confirmed that the water pressure ejected from the pipe is not uniform, and even if the edge is cut in this state, the poor cutting cannot be resolved.

Since the edge cutting nozzle 1 of the above embodiment is configured as described above, as shown in FIG. If two strips of high-pressure water W1 and W2 are simultaneously jetted by each edge-cutting nozzle 1 provided, the high-pressure water W1 that hits the wet paper paper on the upstream side first cuts the edge of the wet paper paper P, and then the edge of the wet paper paper P is cut on the downstream side. On the side, high-pressure water W2 having the same pressure as W1 is further injected to the cutting location.

Therefore, even if the paper is cut incorrectly due to the high-pressure water W1 on the upstream side, the uncut portions will be cut by the high-pressure water W2 on the downstream side, so the wet paper will not run at high speed. Also, it follows this sufficiently and it becomes possible to cut the paper properly without causing cutting defects.

[Effect of idea]

As described above, according to the present invention, two lines of high-pressure water with uniform pressure and uniform amount of water are jetted out simultaneously from a single edge-cutting nozzle, so the water jetting condition is extremely uniform, which is different from the conventional one. Compared to a single-hole nozzle, the sharpness on wet paper is significantly improved.

Furthermore, since two streams of high-pressure water are always spouted from one nozzle, even if pulp scum, etc. adheres to one nozzle, high-pressure water will continue to be spouted from the other nozzle. Therefore, there is no need to stop the conveyor and interrupt the work, and
Even when a plurality of pairs of nozzles are provided, half the number need only be arranged in parallel, which saves space and contributes to making the entire paper manufacturing machine more compact.

Thus, according to the present invention, it is possible to provide a selvage nozzle that can continuously cut wet paper paper, is less likely to cause cutting defects, and can be spaced out in a small space.

[Brief explanation of drawings]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is a side view of the selvedge nozzle, FIG. 2 is a front view of the nozzle tip, and FIG. 3 is a front view of the nozzle base end.
FIG. 4 is an exploded side sectional view of FIG. 1. FIG. 5 is a schematic explanatory diagram showing the jetting state of the selvedge nozzle. 1... Ear cut nozzle; 2... Nozzle body; 3
...Water inlet; 4 ... Headrace channel; 5 ... Spout; 6...
...Nozzle tip; 7... Cap; P... Wet paper;
W1, W2...High pressure water.

Claims (1)

[Scope of utility model registration request] This is an edge cutting nozzle for a paper making machine that cuts edges of conveyed wet paper by pressure jetting water, and includes a single nozzle body and two edges of the same large diameter that each penetrate independently inside the nozzle body. A selvedge nozzle comprising two water channels and two nozzles having the same small diameter formed at the center of the tip of each water channel.