KR930003327B1 - Apparatus for forming wet paper of paper machine - Google Patents

Abstract

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Description

Wetland Formation Device

1 is a layout view of a first embodiment of the present invention.

2 is a layout view of a second embodiment of the present invention.

3 is a layout view of a twin-wire wetland forming apparatus mainly composed of conventional roll dewatering.

4 is an explanatory diagram of a conventional twin wire device.

5 to 7 are layout views each showing an example of a conventional wetland forming apparatus in the twin-wire apparatus.

* Explanation of symbols for main parts of the drawings

(2): paper raw material (2a): wetland

(3): Lower wire (8): Suction pickup roll

(9): upper wire (10): shoebox

(12): Central roll (16): Introduction roll

(17): lead-in Shu (18): auto slice

21: Shuu blade 50: dehydration roll

(51): Save five (52): Vacuum dehydrator

60: Suction Couch Roll

The present invention relates to an apparatus for forming a wetland applied to a paper machine.

A general example of a conventional twin wire device with a phase wire unit is shown in FIG.

The paper raw material 2 ejected from the head box 1 lands on the lower wire 3 of the loop shape, and is dewatered downward by the initial dehydrator 4 below the lower wire 3 to form a wetland 2a. Then, the upper dewatering machine (5) is inserted into the upper wire (9) and the lower wire (3), which form a loop shape to form a draw portion for inserting the paper material (2) by the introduction roll (16). And dewatered upward and downward by the lower dehydrator 6, respectively. Then, the upper wire 9 is separated from the wetland formed on the lower wire 3, and the wetland is dewatered downward by the moisture regulator 7 below the lower wire 3, by the suction pickup roll 8. Off the lower wire 3 is transferred to the subsequent presspaart.

An example of the prior art of the upper dewatering device 5 and the lower dewatering device 6 shown in FIG. 4 is shown in FIG.

The paper raw material 2 shown in FIG. 4 is dehydrated downward by the shoe 27 and the low vacuum box 22, which are the leads of the initial dewatering part 4, and adjusted to a mat concentration of 1.5% to provide a wetland 2a. And a shoe 17 which is a lead of the lower shoe box 10 and fits into the upper wire 9 and the lower wire 3 at the entry portion of the lower shoe box 10 shown in FIG. Pulses of dehydration pressure are applied by the plurality of shoe blades 21 to be dewatered to form a paper layer.

The water dehydrated upward of the shoe box 10 is received in the auto slice 18. The upper wire 9, the paper material, and the lower wire 3 are wound by the curvature in the opposite direction to the curvature of the shoe box 10 by the central roll 12 behind the auto slice 18, and the lower wire. The paper pressure received by (3) and centrifugal force are dehydrated downward, and the upper water sucked from the central roller 12 and the separated portion of the upper wire 9 is taken in by the save oil 23. The wetland wave, which is dewatered between the long side and the upper and lower wires to form a paper layer, is transferred toward the lower wire by the sheet transfer box 14 at the part away from the upper and lower wires.

The conventional upper dewatering device shown in FIGS. 4 and 5, as described above, redisperses the fibers by the pulsed pressure on the shoe box 10 and is again constant by the central roller 12. Due to the combination of dehydration by higher pressure than the shoe, the middle of the roll 100a, 100c and the roll 100a, 100c provided in the loop of the upper wire 9 as shown in FIG. Compared to the so-called hybrid homer mainly composed of dehydration by the roll 100b provided below the lower wire 3, the formation has a great advantage.

However, when the papermaking speed becomes a high speed of 1200 m / min or more, the amount of water entering the upper dewatering device increases because there is a limit to the dewatering of the lower part of the long-term part of a limited length. On the other hand, since there is a certain limit on the dehydration amount in the shoe box 10 as a result, the flow rate entering the subsequent central roll 12 increases. Therefore, in order to perform stable wetland transfer, it is necessary to form a water break line (called wetland concentration of about 6-7%) on the subsequent transfer box 14, and for this, the central roll part 12 There is a need for further dehydration to the bottom of the furnace.

In this case, since a higher wet-water dehydration pressure is received from the central roller 12 in a state where the wetland concentration is low, that is, when the wetland intensity is low, a so-called "crushing phenomenon" tends to occur.

At the same time, as the papermaking speed increases, the dehydration ratio to the upper side decreases. Properties such as formation variation and paper thickness direction strength, which are typical qualities of paper, have a strong correlation with this upper dewatering ratio, and in order to satisfy this property simultaneously, it is necessary to maintain an appropriate upper dewatering ratio. Therefore, as in the conventional wetland formation apparatus, it is not preferable that the upper dewatering ratio has a speed dependency.

Moreover, when the wetland concentration in the sheet transfer box 14 part is low, there exists a problem that sheet transfer becomes unstable and the upper wire 9 becomes easy to be contaminated.

One way to solve these problems is to increase the length of the long section, but the formation tends to deteriorate, and the equipment requires a large space and costs.

In addition, as shown in FIG. 6, the method of installing the vacuum dehydration box 24 in the wire loop of the lower wire 3 in front of the center roll 12 can be considered, but the ratio of the lower dehydration increases. That leaves a problem.

On the contrary, as shown in FIG. 7, if the vacuum dehydrator 32 having a plurality of slots 31 is provided in place of the central roller 12, the above problem is solved, but it corresponds to the dewatering capacity of the central roller. It is necessary to increase the vacuum value because the vacuum dewatering section becomes considerably longer and water is sucked up immediately because it is necessary to provide the number of slots. For this reason, it is necessary to drive the vacuum dehydrator 32 as the upper dewatering device, and the life of the upper wire 9 is also shortened. In addition to this, in a configuration in which water is directly dehydrated, the problem is that a phenomenon in which the fiber fills up in the slot portion can be observed when the mat concentration gradually increases.

The present invention is to provide a wetland forming apparatus that can solve the problems of the conventional twin-wire wetland forming apparatus.

The present invention provides a lower wire which is continuously fed in the form of a loop and fed while dewatering the paper material downward, an upper wire provided against the middle of the lower wire, and formed by the upper and lower wires. An introduction roll disposed to form a draw portion for embedding the wetland, and a loop formed by the upper portion of the lower wire that is dewatered while running around the upper wire, the lower wire, and the wetland, starting from the drawout portion, and curved upwardly A wet paper forming apparatus of a paper machine comprising: a shoe box having a plurality of shoe blades arranged in such a manner; and an oat slice for scraping water dewatered upward by the shoe blades. Wire and Marsh Curvature of the Shuu Blade Vacuum dewatering device having a dewatering roll wound around the curvature in the same direction, a save ool for recovering the water dewatered upward by the desulfurization roll, and a slot disposed in the loop of the upper wire on the downstream side of the save ool. And a central roll in which both wires and the wetland are wound by curvature in a direction opposite to the dewatering roll, and a vacuum dewatering device for transferring the paper layer to the lower wire.

The maximum value (T) of the dewatering pressure applied to the mat in the center roll is the water diameter of the roll diameter (D) and the wire tension (T), In the form of For any given roll diameter and wire tension, the greater the filtration resistance, the greater the pressure generated.

In terms of the paper layer formation process, filtration is generally considered to be dominant, and the mat is formed sequentially from the side closest to the forming wire, and is subjected to an extrusion force to become denser. That is, the filtration resistance is larger than that of the mat formed earlier, and in the present invention, the mat at the bottom of the wetland formed by being dewatered downward by the bottom wire is more dense than the mat at the top, and the filtration resistance is larger.

According to the present invention, a shoe box having a plurality of shoe blades arranged convexly on the upper side is arranged in a lower loop, and a dewatering roll having a wire and a wetland wound up and down by the curvature in the same direction as the curvature of the shoe blade. By this, dehydration is performed upward, that is, toward the upper mat with less filtration resistance. For this reason, a large amount of dehydration can be obtained by a small dehydration pressure. Therefore, the mat concentration is sufficiently high at this point. As a result, the mat density at the time of entering the center roller is sufficiently increased even at a high paper speed, and the "crushing phenomenon" at the center roller can be prevented.

In addition, since the mat concentration is increased by the dehydration to the upper side by the shoe box and the dehydration roll as described above, the contamination of the upper wire is reduced and paper breaking is reduced.

Moreover, even if the papermaking speed becomes high, the paper quality is stabilized without lowering the dewatering ratio at the upper side due to the shoe box and the dewatering roll.

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

A first embodiment of the present invention will be described with reference to FIG.

In FIG. 1, since the same parts as the conventional wetland forming apparatus shown in FIGS. 4 and 5 are denoted by the same reference numerals, the description thereof will be omitted.

In the present embodiment, in the loop of the lower wire 3 of the draw portion of the upper wire 9 formed by the introduction roll 16, the lower part having the shoe 17 as a lead and the plurality of shoe blades 21 is provided. The shoe box 10 is provided. The plurality of shoe blades 21 are bent convexly upward. The auto slice 18 is provided in the loop of the upper wire 9 facing the lower shoe box 10. In the loop of the lower wire 3 downstream of the shoe box 10, the upper and lower wires 9, 3 and the wetland 2a are wound around by the curvature in the same direction as the shoe blade 21. A dewatering roll 50 is provided, and a save-or 51 and a vacuum dehydrator 52 are provided in the loop of the upper wire 9 opposite thereto. On the downstream side of the dewatering roll 50, a central roll 12 is wound around the upper and lower wires 9, 3 and the wetland 2a by curvature in a direction opposite to the dewatering roll 50. The upper and lower wires 9, 3 and the wetland 2a are turned by the central roll 12 to move almost horizontally, and the water regulators are sequentially arranged in the loop of the lower wire 3 of this portion. E (7) and suction couch roll (60) is provided. In addition, (8), the suction pickup roll 15 is a roll for separating the upper wire (9).

In this embodiment, the wetland 2a dehydrated downward by the lower wire 3 is sandwiched by two wires 9 and 3 above and below the shoe 17, which is a lead, to the wire tension. By the shoe blade 21 of the shoe box 10, which is dewatered upward and convexly upward, is mainly dewatered upward. The dewatered water is collected by the auto slice 18 and discharged out of the system. Next, the wetland 2a is dewatered upward by the dewatering roll 50 wound up and down the wires 9 and 3 and the wetland 2a by the curvature in the same direction as the shoe blade 21. And the scattered water enters the save ool 51 and is led out of the system.

Subsequently, dehydration is performed by the vacuum dehydrator 52, but the vacuum value is adjusted to a vacuum value capable of obtaining an optimum upper dehydration ratio while viewing the paper quality. In order to prevent clogging of the slot part of the vacuum dehydrator 52, as shown in the drawing, a larger angle of engagement of the dehydration roll 50 and a space with the central roll 12 are ensured so that the vacuum dehydrator ( The drain hole of 52) is made downward, and clogging is prevented by this. In addition, since the dehydration amount of the vacuum dehydrator 50 is small, a maximum vacuum width of about 3 slots is sufficient.

The upper and lower wires 9 and 3 and the wetland 2a are wound around the central roller 12 by the curvature in the opposite direction to the dehydration roller 50, and the wetland 2a is the copper central roller 12. ) Is subjected to dehydration to the bottom. Since the dehydration to the upper part of the wetland 2a is carried out to the center roll 12 as mentioned above, the mat density of the wetland wound around the center roll 12 is increasing, and the "rolling phenomenon" in the center roll 12 is performed. "This can be avoided. The wave 2a of the wetland is dewatered downward by the central roller 12 and then turned horizontally, and then dewatered again by the moisture control device 7, and the lower wire is transferred on the suction couch roll 60. The suction pickup roll 8 separates the lower wire 3 from the lower wire 3 to the next press piat.

As described above, in the present embodiment, after the water in the wetland 2a is dehydrated upward by the shoe box 10 and the dehydration roll 50, the water is dehydrated downward by the central roll 12. Since the mat concentration of 2a) is increasing, the occurrence of "crushing phenomenon" in the central roller 12 can be prevented.

Moreover, by the shoe box 10 and the dehydration roll 50, even if a papermaking speed becomes high speed, dehydration to a sufficient upper side is performed, and paper quality can be stabilized by this.

Moreover, since the transition of the wetland 2a to the lower wire 3 is performed at the end of the dewatering of the wetland forming apparatus, the concentration of the wetland is high, and since the fiber is hardly attached to the upper wire 9, the copper upper wire The contamination of (9) becomes very small, and can also reduce paper breaks.

A second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the apparatus used and the dehydration function are almost the same as those of the first embodiment, but the deflection in the central roller 12 is large, and the central roller 12 is downstream of the sheet transfer box 14. As a result, the upper and lower wires 9 and 3 and the wetland 2a are moved upward to return to the existing wire height. As a result, the structure of the present invention can be easily converted into the apparatus according to the present embodiment. In addition, each part in FIG. 2 is shown with the code | symbol corresponding to the code | symbol in 1st drawing.

The present invention can exhibit the following effects.

(1) The dewatering capacity of the upper part is improved, and the papermaking speed can be increased without lengthening the long part.

(2) Even if the paper feed speed is high, the paper quality can be stabilized without lowering the rate of dehydration at the top.

(3) By moving the wetland layer to the lower wire after sufficient dehydration, the contamination of the upper wire can be reduced and the number of paper breaks can be reduced.

Claims (4)

Paper wire is continuously supplied in the form of a loop, and the lower wire conveys the paper material while being dehydrated downward, the upper wire provided in the middle of the lower wire, and the formed wetland by the upper and lower wires. An introduction roll arranged to form an interposed draw portion, and a convexly curved convex upwardly arranged in a loop of the lower wire dewatering while traveling around the upper wire, the lower wire, and the wetland starting from the draw portion; A wet paper forming apparatus of a papermaking machine having a shoe box having a plurality of shoe blades arranged and an oat slice for scraping water dewatered upward by the shoe blades, wherein both wires are disposed on a downstream side of the shoe box. And wetlands of the Shue blade Vacuum dewatering with a dewatering roll wound around by the curvature in the same direction as the rate, a save ool recovering the water dewatered upward by the dewatering roll, and a slot disposed in the loop of the upper wire on the downstream side of the save ool. A wetland forming apparatus for a paper machine, comprising: a central roll having a device, both wires, and a wetland wound by curvature in a direction opposite to the dewatering roll; and a vacuum dewatering device for transferring the wetland to a lower wire. 2. The wetland forming apparatus according to claim 1, wherein the upper and lower wires and the wetland, which are forwarded by the central roller, move in a substantially horizontal direction. The wetland forming apparatus according to claim 1, wherein the upper and lower wires and the wetland, which are turned by the central roller, move upward. The wetland forming apparatus of a paper machine according to claim 1, wherein the vacuum dewatering device for transferring the wetland to the lower wire is a suction couch.

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