JP2002138383A - Dehydrating apparatus for paper machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dehydrating apparatus for a paper machine, capable of further increasing efficiency of water removal of wet paper. SOLUTION: A wet paper M is pressed against a suction roller 23 side through a water absorption material 22 by a pressing roller 29. Water squeezed out by pressing through holes 23a formed on the outside of the suction roller 23 is sucked in a suction box 23b arranged inside the suction roller by the suction roller 23. The water absorption material 22 is composed of an electroconductive material and is connected through a guide roller 25 to an anode of a DC power supply source 30. A cathode of the DC power supply source 30 is connected to the suction roller 23. Thus, a state in which a DC voltage is applied between the water suction material 22 and the suction roller 23 is prepared.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a dewatering device for a paper machine.

[0002]

2. Description of the Related Art As a paper machine, a type having a wire part and a press part is conventionally known. In this type of paper machine, the pulp slurry is formed into wet paper in the wire part, and the moisture of the formed wet paper is removed by the press part to dewater the paper. Water removal is usually
This is performed by placing a wet paper web on a water-absorbing material such as felt, and allowing the water-absorbing material to absorb the moisture in the wet paper web.

[0003] In addition to the above-described water removal by a water-absorbing material, a method of removing water from wet paper, that is, dewatering more efficiently by separately providing a dewatering device, for example, in the former stage of the press part, is also used. ing. As this type of dewatering device, a device using a suction press roll member is generally used. The suction press roll member includes, for example, a pressing roller (compression roller) and a suction roller. Then, the moisture of the wet paper is pressed and squeezed by a pressing roller, and the squeezed water is sucked by a suction roll. Such a suction press roll member is usually provided with one stage or several stages as necessary.

[0004] By the way, even in the case where the suction press roll member is provided as described above, at present, it is impossible to effectively remove moisture from the wet paper web. For this reason, attempts have been made to efficiently dehydrate by changing the pressing force of the pressing roller, the suction force of the suction roller, the size and arrangement pitch of the suction holes provided in the suction roller, and the like. However, if the pressing force or the suction force is too large, the wet paper web will be crushed or the degree of vacuum will be reduced due to the suction of air, and the dewatering rate will be reduced. Further, when the hole is large or the suction force is too strong, there is a problem that a so-called shadow mark is generated.

On the other hand, for example, Japanese Patent No. 3019416
As disclosed in Japanese Patent Application Laid-Open No. H10-260, there has been proposed a method of performing water removal more efficiently by using an electric suction force in addition to the conventional mechanical water removal by squeezing and suction. In this method, a DC voltage is applied between the suction roller and the pressing roller, and an electroosmotic action by applying the DC voltage is used.

[0006]

However, the combined use of the above-mentioned electroosmotic action can increase the efficiency of water removal in the dehydrating apparatus, but this kind of efficiency improvement and the accompanying speedup of the papermaking process are improved. The demand for this has been increasing, and there has been a limit in meeting this demand.

[0007] The present invention has been made in view of the above circumstances,
An object of the present invention is to provide a dewatering device for a paper machine that can further increase the efficiency of removing moisture from wet paper.

[0008]

According to the present invention, there is provided a dewatering apparatus for a paper machine which comprises at least a part of a press part for dewatering wet paper made in a wire part in order to solve the above-mentioned problems. A dewatering device for a machine, a pressing member provided on one surface side of the wet paper web and pressing the wet paper web, and a water squeezed by the pressing provided on the other surface side of the wet paper web. A suction member for sucking, having a conductive water-absorbing material sandwiched between the pressing member and the wet paper, and applying a DC voltage between the water-absorbing material and the suction member; It is characterized by.

In the above configuration, the water-absorbing material may be formed as an endless belt, and may be disposed via a guide roller so as to run endlessly on the outer surface of the pressing member.

[0010] In the above configuration example, a DC voltage may be applied to the water-absorbing material via the guide roller. Alternatively, a configuration in which a DC voltage is applied to the water-absorbing material via the pressing member may be adopted.

The suction member can be constituted by, for example, a hollow suction roller having a suction hole formed on an outer surface thereof. Further, the pressing member can be constituted by, for example, a pressing roller. Further, the pressing member may include a pressing surface having a shape corresponding to the outer surface of the suction member, and a DC voltage may be applied between the pressing roller and the suction roller.

In the dewatering device for a paper machine of the present invention having the above-mentioned structure, the conductive water-absorbing material is in a state of facing the outer surface of the suction member in a planar manner. On the other hand, in the above-described conventional configuration in which a DC voltage is applied between the pressing roller and the suction roller, the pressing roller and the suction roller are in a state where their outer surfaces are linearly opposed. Therefore, in the present invention, the facing area between the two members (the suction member and the water-absorbing material) to which a DC voltage is applied can be significantly increased as compared with the above-described conventional configuration.

Therefore, if a DC voltage is applied between the conductive water-absorbing material and the suction member as described above, the electroosmotic action can be remarkably enhanced as compared with the above-described conventional configuration.

The dewatering device for a paper machine according to the present invention is a dewatering device for a paper machine constituting at least a part of a press part for dewatering the wet paper made in the wire part. A pressing member that is provided on the surface side of the wet paper web and presses the wet paper, and a suction member that is provided on the other surface side of the wet paper web and sucks the moisture squeezed out by the pressing. In a paper machine dewatering device obtained by applying a DC voltage between the suction member, one of the pressing member and the suction member has a convex outer surface, the other has a concave shape corresponding to the convex shape. Having an outer surface.

Further, the paper machine dewatering apparatus of the present invention is a paper machine dewatering apparatus constituting at least a part of a press part for dewatering the wet paper made in the wire part. A pressing member that is provided on the surface side of the wet paper web and presses the wet paper, and a suction member that is provided on the other surface side of the wet paper web and sucks the moisture squeezed out by the pressing. In a dewatering device for a paper machine in which a DC voltage is applied between the suction member and the suction member, both outer surfaces of the pressing member and the suction member are substantially flat.

In the dewatering device for a paper machine having the above-described structure, since the outer surfaces of the pressing member and the suction member are formed to have corresponding uneven surfaces, or both have substantially planar shapes, the facing area between the outer surface of the pressing member and the outer surface of the suction member is reduced. It can be much larger than the above conventional configuration. For this reason, the electroosmotic action can be remarkably enhanced as described above.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A dewatering apparatus for a paper machine according to a first embodiment of the present invention will be described in detail below.

Here, the paper machine comprises a wire part, a press part, a dryer part and the like. And
In the wire part, paper is formed from pulp slurry to wet paper M by a papermaking screen (not shown). Further, the wet paper web M thus formed is dried in the dryer part after water is removed in the press part. Further, referring to FIG. 1, the press part includes a plurality of stages, usually three to four stages of suction units. FIG. 1 shows only the two suction units 1 and 2 located at the final stage.

The suction unit 1 includes a pair of endless belt-shaped water absorbing materials 11 and 12 on which the wet paper M is placed, and the water absorbing materials 11 and 12.
The rollers 12 and 14 are provided to allow the endless running of the motor 12 in the direction of the arrow. And wet paper M
The water absorbing material 1 is sandwiched between the water absorbing materials 11 and 12.
The air is conveyed to the suction unit 2 at the next stage along with the travels of 1 and 12. During this traveling, the moisture in the wet paper web M is absorbed by the water absorbing material 1.
The water is removed from the wet paper web M by being gradually adsorbed to the first and second sides. In the present embodiment, a suction unit (not shown) located at a stage before the suction unit 1 has the same configuration as the suction unit 1.

The suction unit 2 is a dewatering device for a paper machine according to the embodiment, and a pair of endless belt-shaped water-absorbing materials 21 between which the wet paper web M sent from the suction unit 1 is clamped.
22. The suction unit 2 further includes a suction roller 23, guide rollers 24-28, a pressing roller 2
9, a DC power supply 30 and the like. Here, the water absorbing material 2
2 is for felt and woven fabric used for this kind of water absorbing material,
Conductivity is imparted by mixing conductive fibers (conductive fibers) such as carbon fibers and metal fibers. In addition, since the conductive fibers are consumed by electron transfer during electroosmosis, which will be described later, inexpensive metal fibers and carbon fibers are preferably used. Alternatively, metal fibers such as platinum which do not wear out can be used.

The suction roller 23, the guide roller 2
Guided by 4 and 25, the water absorbing material 21 travels endlessly in the direction of the arrow. Also, the guide rollers 26 to
Guided by 28, the water absorbent 22 travels endlessly in the direction of the arrow. In addition, as described above, the water absorbing material 21,
In order to make the 22 travel, for example, the suction roller 23 and the guide rollers 24 to 28 are appropriately rotated by a driving device (not shown).

The suction roller 23 is a hollow cylindrical member made of a conductive material. For example, as shown in FIG. 2, the suction roller 23 has a plurality of holes 2 for suction (water absorption) on its outer surface.
3a are formed. A suction box 23 connected to a vacuum device (not shown) is provided inside the suction roller 23.
b is accommodated, and a suction force to the suction roller 23 is generated in the hole 23a by the negative pressure generated in the suction box 23b. Therefore, as will be described later, the moisture in the wet paper web M squeezed out by the pressing by the pressing roller 29 is sucked into the suction box 23b through these holes 23a, and the vacuum device is drawn from the suction box 23b through a path (not shown). Drained to the side.

The pressing roller 29 is a cylindrical member made of a non-conductive material, and may be solid or hollow. Then, the pressing roller 29 is connected to the suction roller 23.
, The water absorbing material 22 and the wet paper web M are pressed by the pressing force P. As a result, the wet paper web M is compressed by the pressing force P together with the water absorbing material 21, and the water squeezed out by this compression is sucked and discharged through the holes 23a on the outer surface of the suction roller 23 as described above.

On the other hand, at least the outer surface of the guide roller 26 is made of a conductive material. The water absorbing material 22 is made of a conductive material. And
An anode of a DC power supply 30 is connected to the guide roller 26,
Since the water-absorbing material 22 travels while being in contact with the outer surface of the guide roller 26, the water-absorbing material 22 is also connected to the anode of the DC power supply 30, and is maintained at the same potential as the guide roller 26. A cathode of a DC power supply 30 is connected to an outer surface of the suction roller 23. As a result, the DC voltage of the DC power supply 30 is applied between the water absorbing material 22 and the suction roller 23.

In the dry part of the paper machine having the above configuration, in the suction part 1 and a suction part (not shown) preceding the suction part 1, the moisture in the wet paper web M is absorbed by the water absorbing material (the example shown in FIG. 1). In this case, the water absorbing material may be provided only on one side, but the water absorbed gradually is removed.

The same applies to the water absorbing section 2.
Moisture removal is carried out by absorbing moisture into the first and the second 22. Further, since a DC voltage is applied between the water absorbing member 22 and the suction roller 23 in the water absorbing section 2, the water permeation by the DC voltage further removes water from the wet paper web M as compared with other water absorbing sections. It can be done effectively.

Referring to FIG. 2, the above-mentioned electroosmosis is carried out by a DC voltage applied between the water-absorbing material 22 and the suction roller 23. 22 means that the water in the wet paper web M moves to the suction roller 23 side through the water absorbing material 21. The amount of water sucked and removed from the wet paper web M through the hole 23a of the suction roller 23 and the removal efficiency can be remarkably increased by the electroosmosis.

Here, in the embodiment shown in FIG. 1, the guide rollers 26 and 27 arranged adjacent to the suction roller 23 have their lower surfaces located below the upper surface of the suction roller 23. ing. With this configuration, it is possible to increase the area of the water-absorbing material 22 located on the outer surface of the suction roller 23 so as to face the same. By appropriately adjusting the relative position of the guide roller 26 or the guide roller 27 with respect to the suction roller 23 in this manner, the suction roller 2
The area of the water-absorbing material 22 facing the peripheral surface of No. 3 can be adjusted. And by increasing or decreasing the size of this area,
The magnitude of the electro-osmosis can be increased or decreased as needed.

In the above example, the conductive guide roller 2
6, the anode of the DC power supply 30 is connected to the water absorbing material 22. Alternatively, for example, at least the surface of the pressing roller 29 is made conductive, and the anode of the DC power supply 30 is connected to the pressing roller 29. By doing so, the pressing roller 29
The anode may be connected to the water-absorbing material 22 through the intermediary of the anode.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
The main part of the paper machine dewatering device of the embodiment is shown. This dewatering device for a paper machine replaces the pressing roller 29 in FIG. 1 with a biasing member 2 such as a spring as shown in FIG.
Pressing member 29 pressed toward suction roller 23 by 92
Except for using 1, the configuration is the same as that of the first embodiment.

The pressing member 291 has a concave surface (concave spherical surface) whose pressing surface 291a facing the suction roller 23 corresponds to the convex surface (convex spherical surface) of the suction roller 23. Therefore, in the second embodiment, the guide rollers 26 and 27 are connected to the suction roller 2 as illustrated in the first embodiment.
3, the contact area of the water absorbing material 22 facing the outer surface of the suction roller 23 can be secured to a desired size by the pressing member 291.

(Third Embodiment) FIG. 4 shows a third embodiment of the present invention.
The main part of the paper machine dewatering device of the embodiment is shown. The dewatering device for a paper machine differs from the embodiment of FIG. 1 in that a suction member 231 is used instead of the suction roller 23.
1 is not conductive, the anode of the DC power supply 30 is directly connected to the pressing roller 293, the wet paper M and the water absorbing material 211
(That is, the wet paper web M is pressed by the pressing roller 29).
The water-absorbing material 211 is disposed on the water-absorbing member 231 on the third side.)
Except for the above, the configuration is the same as that of the first embodiment.

The positions of the wet paper M and the water absorbing material 211 are the same as those in the first embodiment, that is, the wet paper M is moved to the water absorbing member 2.
A configuration in which the water absorbing material 211 is disposed on the pressing roller 293 side on the 31 side may be employed. Further, a configuration in which a water absorbing material is arranged on both sides of the wet paper web M and the wet paper web M is sandwiched between the water absorbing materials may be employed. Also,
At least one of the water-absorbing materials disposed on one or both sides of the wet paper web M may be made of a conductive material as in the first embodiment.

The above-mentioned suction member 231 is
3 is a concave outer surface (concave spherical surface) corresponding to the convex outer surface (convex spherical surface) of the pressing roller 293. Thereby, the facing area between the outer surface of the suction member 231 to which the cathode of the DC power supply 30 is connected and the outer surface of the pressing roller 293 to which the anode is also connected is significantly increased as compared with the conventional configuration. Therefore, as in the case of the first embodiment, the amount of water sucked and removed from the wet paper web M through the hole 23a of the suction member 231 and the removal efficiency can be significantly improved.

(Fourth Embodiment) FIG. 5 shows a fourth embodiment of the present invention.
The main part of the paper machine dewatering device of the embodiment is shown. The dewatering device for a paper machine uses a pressing member 294 instead of the pressing roller 293, and the suction member 2 instead of the suction member 231.
32 and the water absorbing material 21 on both sides of the wet paper web M.
The configuration is similar to that of the third embodiment, except that 2, 213 are arranged. In the fourth embodiment, as in the case of the third embodiment, a configuration in which the water absorbing material is arranged on only one side of the wet paper web M may be used.

That is, the pressing member 294, the suction member 23
Numeral 2 is obtained by bending both ends of a flat plate material slightly downward and upward to form the illustrated shape. The opposing surfaces at the center of the pressing member 294 and the suction member 232 are substantially flat. By making the two opposing surfaces flat, the outer surface of the suction member 232 to which the cathode of the DC power supply 30 is connected and the outer surface of the pressing member 294 to which the anode is also connected, as in the third embodiment. Is increased, and the amount of water to be sucked and removed from the wet paper web M through the hole 23a of the suction member 232 and the removal efficiency can be significantly improved.

[0037]

Since the present invention is as described above, the electroosmotic action can be increased to such an extent that a practical effect can be obtained, and the efficiency of removing moisture from wet paper can be increased.
By improving the water removal efficiency, effects can be obtained such that the drying in the dryer part next to the press part can be performed easily and reliably.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a dewatering device for a paper machine according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of the dewatering device for a paper machine of FIG.

FIG. 3 is an explanatory view of a main part of a dewatering device for a paper machine according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of a main part of a dewatering device for a paper machine according to a third embodiment of the present invention.

FIG. 5 is an explanatory diagram of a main part of a dewatering device for a paper machine according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Suction part 2 Suction part 11 Water absorption material 12 Water absorption material 21 Water absorption material 22 Water absorption material 23 Suction roller 23a Hole 23b Suction box 29 Press roller 30 DC power supply 231 Suction member 232 Suction member 291 Press member 294 Press member

Claims (9)

[Claims] 1. A dewatering device for a paper machine, which constitutes at least a part of a press part for dewatering a wet paper made in a wire part, wherein the dewatering device is provided on one surface side of the wet paper, and A pressing member for pressing the paper, a suction member provided on the other surface side of the wet paper for sucking moisture squeezed out by the pressing, and a conductive member sandwiched between the pressing member and the wet paper. A dewatering device for a paper machine, wherein a DC voltage is applied between the water absorbing material and the suction member. 2. The paper machine according to claim 1, wherein the water-absorbing material is in the form of an endless belt, and is disposed via a guide roller so as to run endlessly on the outer surface of the pressing member. For dehydration equipment. 3. A dewatering apparatus for a paper machine according to claim 2, wherein a DC voltage is applied to said water-absorbing material via said guide roller. 4. The method according to claim 1, wherein a DC voltage is applied to the water absorbing material via the pressing member.
The dewatering device for a paper machine according to the above. 5. The dewatering device for a paper machine according to claim 1, wherein the suction member is a hollow suction roller having a suction hole formed on an outer surface thereof. 6. The dewatering device for a paper machine according to claim 1, wherein the pressing member is a pressing roller. 7. The dewatering device for a paper machine according to claim 1, wherein the pressing member has a pressing surface having a shape corresponding to an outer surface of the suction member. . 8. A dewatering apparatus for a paper machine, which constitutes at least a part of a press part for dewatering a wet paper made in a wire part, wherein the wet paper is provided on one surface side of the wet paper. And a suction member provided on the other surface side of the wet paper web for sucking moisture squeezed out by the pressing, and applying a DC voltage between the pressing member and the suction member. In the paper machine dewatering device obtained by applying, one of the opposing surfaces of the pressing member and the suction member has a convex outer surface, and the other is a concave outer surface corresponding to the convex shape. Characteristic dewatering device for paper machine. 9. A dewatering device for a paper machine, which constitutes at least a part of a press part for dewatering wet paper made in a wire part, wherein the wet paper is provided on one surface side of the wet paper. And a suction member provided on the other surface side of the wet paper web for sucking moisture squeezed out by the pressing, and applying a DC voltage between the pressing member and the suction member. A dewatering device for a paper machine, wherein the opposing surfaces of the pressing member and the suction member are substantially flat.