JPH0547678B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a paper layer forming device that can be applied to a double wire wire part having a fixed dewatering device.

(Prior Art) FIG. 4 shows an example of a conventional double wire Fourdrinier paper machine (wire part), and dewatering is performed as follows. That is, the raw material 2 ejected from the head box 1 is sandwiched between wires 3 and 4, passes through a dewatering section 5 called a forming shoe, a suction box 7, and a suction couch roll 8, where it is dehydrated to become wet paper, and is then pressed into a press. Transferred to part time. The dewatering section 5 is supported in an arc shape by a dewatering blade 6, and dehydrates the raw material by pushing the dewatering blade and pressure generated by the wire tension.
The seeped white water is removed by centrifugal force and the scraping action of the blade, as shown in Figure 3.

However, in such a conventional wire part, the wire is supported at points at the tip 9 of the blade as shown in FIG. 3, and the curvature of the bending part when the wire runs is large, so the wire wears out considerably. Since pressure is generated instantaneously and water is removed, there are drawbacks such as poor yield of raw materials, especially fine fibers and fillers.

(Problems to be Solved by the Invention) The present invention attempts to solve conventional problems such as poor yield of fine fibers and fillers.

(Means for Solving the Problems) Therefore, the present invention is arranged on one side of two wires sandwiching the raw material in the first half of the dewatering section from the head box to the suction couch roll, and A plurality of dewatering blades are provided that support the wire at the rear end with respect to the direction, and have surfaces that form a wedge space that narrows as the wire runs between the wire on the support side and the wire on the side of the wedge space. This is a method to solve the problem by pushing back the white water seeping out from the wire surface and at the same time dewatering only from the opposite wire surface to increase the raw material concentration between the wires. be.

(Function) Now, when the two wires sandwiching the raw material approach the dewatering blade, pressure is generated on the raw material due to the pushing and the tension of the wire, and the raw material oozes out on both sides of the two wires. The white water seeping out to the dewatering blade side is swallowed up by the wedge space, but from the moment the liquid level of the white water wets the blade surface, it is pressed in the opposite direction, and all but the white water that acts as a lubricant is pushed back toward the raw material side. It has the effect of floating the wire on the blade side.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 and FIG. 2 show one embodiment of the present invention. In the figure, a raw material 22 ejected from a head box 21 is sandwiched between two wires 23 and 24, and is dehydrated while forming a formation in a dewatering section 25 in the first half. This dewatering section 25 supports the wire 24 at the rear end with respect to the running direction of the wires 23 and 24,
A plurality of dewatering blades 26 are arranged so as to have a wedge space between them and the wires 24, and the wires 23 and 24 are supported in an arc shape. Further, the supporting direction of the blade 26 is approximately on the normal line of the circular arc, and the moment applied to the blade is small, and dewatering by the blade is also performed outside the circular arc, so there is no need to bother with white water treatment, and these blades The structure (not shown) supporting 26 also has a very simple structure.

Now, the raw material 22 that has passed through the dewatering section 25 is rapidly dehydrated by a suction oil box 27, a suction box 28, and a suction couch roll 29, and then transferred to a press part. Note that the supporting direction of the blade 26 may be the direction in which the force received by the wire tension and the frictional force with the wire are combined, and since most of the force is due to the bending moment frictional force, the supporting direction is much smaller than the conventional one. This also simplifies the support adjustment method.

Here, the differences in visual phenomena and configurations between the present invention and the conventional dehydration apparatus shown in FIGS. 2 and 3 are as follows:
As shown by the dotted line, the direction in which dehydrated white water is removed is different, the present invention has a wedge-shaped space 30 between the wires 23 and 24, and the angle of the dewatering blade 26 with respect to the wire is different. 3 with points
There are several points.

Next, the operation of the embodiment configured as above will be explained. Two wires 23, 2 sandwiching the raw material
When the raw material 2 approaches the dewatering blade 26, its pushing and the tension of the wires 23 and 24 remove the raw material 2.
Pressure is generated in the wires 23 and 24, and white water oozes out from both sides of the two wires 23 and 24. The white water seeping out to the dewatering blade 26 side is transferred to the dehydrating blade 26 and the wire 24.
However, from the point at which the liquid surface of the white water wets the surface of the blade 26, it is pressed in the opposite direction and other than the white water to the extent that it acts as a lubricant between the wire and the blade. It is pushed back to the raw material 22 side again. This action also has the effect of lifting the wire on the blade side, albeit slightly, and reduces the curvature of the bend.

(Effects of the Invention) As explained in detail above, the present invention is arranged on one side of two wires sandwiching a raw material, supports the wire at the rear end in the running direction of the wire, and supports the wire on the support side. Since a plurality of dewatering blades are provided with surfaces that form a wedge space that narrows as the wire runs between the two wires, the wire on the wedge space side is removed from the white water seeping out from both sides of the two wires. The white water seeping out from the surface is pushed back into the wire, dewatering only from the opposite wire surface, increasing the concentration of raw material between the two wires, and expanding the dewatering pressure range. , it can also greatly soften the impact when passing over the blade.

That is, the raw material between the wires is dehydrated toward the outer wire, but since the white water outlet is halved and the white water is pushed back due to the wedge effect, concentration and dilution are simultaneously performed between the wires. Therefore, some of the raw material between the wires tends to flow to the upstream side where the pressure is lower. This results in the white water oozing out from the two wires to both sides even earlier, but this phenomenon only has a temporary retention effect and the amount of water passing over the blade is uniform. Therefore, the amount of water removed per blade is inferior to that of the conventional method because the water is removed from one side midway through, but the change in the distance between the wires is also smaller due to the smaller amount of water removed, and the outer wire is The curvature also becomes smaller.

In other words, the white water swallowed into the wedge space causes the blade side wire to float up, and the dewatering start point moves up due to the effect of the white water flowing upstream.
Due to the relatively thick distance between the wires, etc., the dewatering time can be doubled compared to the conventional method, and the impact on the raw material in this dewatering section can be greatly reduced.

Therefore, according to the present invention, since the impact strength exerted on the raw material is weakened and the dehydration time is long, the yield of raw materials, especially fine fibers and fillers, is improved. In addition, since the white water that is dehydrated as a result moves only in one direction, the strength in the paper thickness direction increases. Peeling) is improved. Furthermore, since the amount of white water moving is large, the formation is well dispersed, and the white water that seeps toward the blade side acts as a lubricant, reducing frictional resistance, reducing driving power, and extending the life of the wire. be able to. In addition, the force applied to the blade is reduced, the structure that supports it is simpler and cheaper, and adjustment is easier.
The shape of the blade tip (contact part) has little effect on quality, and the degree of accuracy required can be reduced.

[Brief explanation of drawings]

Fig. 1 is a side view of a wire part equipped with a paper layer forming device showing an embodiment of the present invention, Fig. 2 is a detailed view of the same main part, and Fig. 3 is a conventional dewatering device shown corresponding to Fig. 2. A side view of the blade portion, FIG. 4 is a side view of a conventional double wire type wire part. Explanation of main parts of the figure, 21...Head box, 22...Raw material, 23, 24...Wire, 25
... Dewatering section, 26 ... Dewatering blade, 29 ... Suction couch roll, 30 ... Wedge-shaped space.

Claims (1)

[Claims] 1 In the first half of the dehydration section from the head box to the suction couch roll, two
The surface is disposed on one side of a piece of wire, supports the wire at the rear end in the running direction of the wire, and forms a wedge space between it and the wire on the support side that narrows as the wire runs. A plurality of dewatering blades were installed to push back the white water seeping out from the wire surface on the wedge space side, and at the same time dewatering only from the wire surface on the opposite side, increasing the raw material concentration between the wires. Characteristic paper layer forming device.