WO2006030507A1

WO2006030507A1 - Papermaking machine and papermaking method

Info

Publication number: WO2006030507A1
Application number: PCT/JP2004/013544
Authority: WO
Inventors: Hideo Nogami; Shigenari Horie; Masahiro Sugihara; Hiroshi Iwata
Original assignee: Mitsubishi Heavy Industries, Ltd.
Priority date: 2004-09-16
Filing date: 2004-09-16
Publication date: 2006-03-23
Also published as: US20070209769A1; CN101010459A

Abstract

A papermaking machine and papermaking method for making a paper by removing moisture from a paper material layer while it is made to travel, in which the paper material layer can be dewatered more efficiently. A perpermaking machine for making paper by removing moisture from a paper material layer (1) while it is caused to travel, where the paper material layer (1) is a layer of a paper material liquid (1a) ejected from a head box (2) and held in a layer form. The above part for removing the moisture has a steam heating means (6) that is provided as a means for heating the paper material layer (1) to accelerate the moisture removal and that supplies steam to the paper material layer (1) and heats the layer (1) through condensation of the steam, and has a means (11) for regulating condition of the steam supplied by the steam heating means (6) such that the paper material layer (1) has a preset target temperature, the condition regulation being made depending on a material concentration state of the paper material layer (1) when it passes through the steam heating means (6).

Description

Specification

Paper machine and method

Technical field

The present invention relates to a papermaking machine and a papermaking method in which papermaking is carried out by removing water while running a paper material layer.

Background art

In general, in a paper machine, a pulp suspension (paper material solution) jetted from a head box is held in layers by a wiper or the like, and the paper material layer (hereinafter also referred to as wet paper) is allowed to travel while being moistened. To remove paper and to make paper!

Various methods of dewatering in a paper machine have been developed. For example, as shown in FIG. 8 (a), Patent Document 1 discloses a method of dewatering on the runway at the final part of the former (forming part or paper layer forming part). A paper machine comprising a steam box 60 for supplying steam to the surface of a wet paper web 1 is disclosed.

In such a paper machine, the steam from the steam generation source 10 is supplied to the steam bottos 60 through the steam introduction pipe, and the steam is brought into contact with the wet paper web 1 held on the wire 30. It condenses and transfers heat.

In the final part of the former, the wet paper web 1 is considered to be in a state before completion of dewatering, that is, in a state in which dewatering proceeds to form a space or a porous state. By suctioning the lower surface of the wet paper 1 through the vapor, the steam enters such voids and pores and penetrates the inside of the wet paper 1. As a result, the latent heat of the steam is converted to the sensible heat of water to heat the wet paper, thereby improving the dewatering rate.

The dewatering rate of the wet paper web 1 traveling through the former is not uniform, and generally the dewatering rate is lower at the widthwise center of the wet paper web 1 than at the left and right ends in the width direction. Therefore, as shown in FIG. 8 (b), the inside of the steam box 60 is in contact with the center of the wet paper web 1 whose dewatering rate is relatively low, compared with the width direction left and right sides. The steam supply chamber 61 is divided into a plurality of sections in the width direction to form the steam supply chamber 61, and the steam supply chamber located at the central portion in the width direction by appropriately operating the valve 11 opening corresponding to each steam supply chamber 61. 61, the steam supply chamber 61 located on the left and right sides in the width direction Techniques have been developed to provide more steam than steam.

[0005] Patent Document 2 also discloses a technique for raising the temperature of the wet paper by bringing the wet paper into contact with the vapor as described above.

Patent Document 1: Japanese Patent Application Laid-Open No. 55-137293

Patent Document 2: US Patent No. 5,149,401

Disclosure of the invention

Problem that invention tries to solve

By the way, the present inventors have intensively researched the dewatering rate of wet paper by steam heating, and even if the amount of supplied steam is increased to further increase the dewatering rate, the dewatering rate decreases. I found that I might have This is thought to be due to the increase in the amount of steam supplied and the amount of water condensed into water.

However, the above-described conventional paper machine does not pay attention to such a change in dewatering rate with respect to the amount of supplied steam, and does not necessarily set an optimum amount of supplied steam. If dehydration is done efficiently, it leaves problems in the point.

Means to solve the problem

The present invention has been made in view of the above problems, and an object of the present invention is to provide a papermaking machine and a papermaking method in which a paper material layer can be dewatered more efficiently in a papermaking machine.

For this reason, the paper machine of the present invention according to claim 1 is a papermaking method in which paper making is carried out by removing moisture while running the paper material layer while holding the layer material solution jetted from the headbox force in layers. Is provided as a heating means for heating the paper material layer (wet paper) in order to accelerate the water removal, and the steam is supplied to the paper material layer to promote the removal of moisture. Steam-type heating means for heating the paper material layer by the condensation action, and the raw material concentration state of the paper material layer when passing through the steam-type heating means so that the paper material layer reaches a preset target temperature. And an adjusting means for adjusting a steam supply state by the steam-type heating means.

[0010] The steam referred to here is not limited to saturated steam, and may be, for example, heated steam, moist air, or the like. In addition, the raw material concentration state of the above-mentioned paper raw material layer is detected in real time, and the amount of steam supplied is adjusted based on the detection information, or the raw material concentration state of the paper raw material layer is It is determined beforehand, and the amount of supplied steam is adjusted based on the previously determined raw material concentration state.

[0011] According to the paper machine of the present invention as set forth in claim 2, in the constitution according to claim 1, the water removing part holds the paper stock solution which has also jetted the head box force in a layered manner to make the paper stock layer. A former that dewaters water while running to form a paper layer (also referred to as a forming part or a paper layer formation part) or applies pressure to the paper material layer on which a paper layer is formed by the former to further dehydrate water It is characterized by being a press part.

[0012] According to the paper machine of the present invention as set forth in claim 3, according to the construction as set forth in claim 2, the forming part is configured as a twin wire former having wires on both sides of the paper material layer. It is characterized by The present invention is not necessarily limited to the twin wire, and may be a long net type former that holds only one side of the paper material layer, or an on top form.

According to a fourth aspect of the present invention, there is provided a paper machine according to the third aspect, wherein the steam heating means is provided with a steam box for guiding the supply of steam to the paper material layer. The steam box is disposed such that the opening periphery of the tip is brought into contact with or close to the wire.

In the paper machine of the present invention according to claim 5, in the construction according to claim 4, sealing means for sealing the inside and the outside of the steam box is provided on the periphery of the opening of the tip of the steam box. As a feature! /.

[0014] The paper machine of the present invention according to claim 6 is the construction according to claim 5, wherein the sealing means is attached to the periphery of the tip opening of the steam box and abuts against the wire. It is characterized by being.

In the paper machine of the present invention according to claim 7, in the construction according to claim 5, the sealing means is provided on the upstream side in the traveling direction of the paper material layer than the periphery of the tip opening of the steam box. It is characterized in that it is a gas injection device that suppresses the entrance of the wake of the paper material layer into the steam box by injecting. Further, in this case, it is preferable that the gas injection device directs the gas upstream at an injection angle of about 15 ° to 40 ° with respect to the wet paper. [0015] The paper machine of the present invention according to claim 8 has the structure according to any one of claims 1 to 7, wherein the steam box is placed on the opposite side of the paper box from the steam box. A suction box is provided to suck the steam injected from the pipe.

In the paper machine of the present invention according to claim 9, according to the construction according to claim 8, the downstream end of the paper material layer of the suction bottons in the running direction is closer to the downstream end of the steam box in the running direction. It is located downstream and is characterized by

[0016] The paper machine of the present invention according to claim 10 has the construction according to claim 8 or 9, wherein the paper material layer runs on the opposite side of the paper material layer from the steam box. Another feature is that another suction box is provided downstream of the direction.

In the paper machine of the present invention according to claim 11, in the configuration according to claim 10, the suction force of the suction box on the downstream side in the traveling direction of the paper material layer is set larger than the suction force of the suction box on the upstream side. It is characterized by

[0017] The paper machine of the present invention according to claim 12 has the construction according to any one of claims 8-11, wherein the inside of the steam box is divided into a plurality of parts in the width direction of the paper material layer. The interior of the suction box is divided into a plurality of sections in the width direction of the paper material layer so as to correspond to the divisions in the vapor box, and in the vapor box and in each of the divided area units in the suction box. It is characterized in that it is possible to adjust the steam injection state and the steam suction state.

[0018] In the paper machine of the present invention as set forth in claim 13, in the construction as set forth in any one of claim 1, the vapor supplied by the steam type heating means collides with the paper material layer. It is characterized in that the paper material layer is heated by acting as a jet.

The paper machine of the present invention according to claim 14 is characterized in that, in the configuration according to any one of claims 1 1 to 13, a control means for automatically adjusting the adjustment means is provided. /

[0019] The paper machine of the present invention according to claim 15 has the structure according to claim 14, wherein the raw material concentration of the paper raw material layer when passing through the steam type heating means is made in the vicinity of the steam type heating means. A raw material concentration detection means for detecting is provided, and the control means It is characterized in that the state of steam supply by the steam type heating means is controlled so that the paper material layer is heated up to the target temperature based on the detection information by the stage. Further, the above-mentioned raw material concentration detection means is, for example, a moisture content sensor, and it is possible to estimate the moisture content and raw material concentration of the paper raw material layer detected by this moisture content sensor.

[0020] The paper machine of the present invention according to claim 16 has the configuration according to any one of claims 1 115, wherein the traveling direction downstream side of the paper material layer is provided from the installation location of the steam heating means. Further, as a heating means for heating the paper material layer, there is provided an air jet type heating means for blowing high temperature air to the paper material layer and heating the paper material layer by a collision jet of the high temperature air. It is characterized.

[0021] The paper machine of the present invention according to claim 17 has the structure according to any one of claims 1 116, wherein as the heating means, the first heating is performed by heating from one side of the paper material layer. It is characterized in that a means and a second heating means for heating from the other side of the paper material layer are provided.

A papermaking method according to claim 18, wherein the paper stock solution jetted from the head box is held in a layered form and water is removed while running the paper stock layer to perform paper making. Steam is supplied to the paper material layer at the heating target location so that the paper material layer reaches a preset target temperature, and the paper material layer is heated by the condensation action of the steam, and then the paper material material is heated. It is characterized by absorbing and removing moisture. As described above, the steam referred to here is not limited to saturated steam, and may be, for example, heated steam, moist air, or the like.

Effect of the invention

[0022] According to the paper machine of the present invention as set forth in claim 13, in the part for removing water, steam heating means is provided so that the paper material layer reaches a preset target temperature by the adjustment means. Since the supply state of steam by the steam type heating means is adjusted according to the raw material concentration state of the paper raw material layer at the time of passing, it is possible to more efficiently heat and dewater the paper raw material layer. This can improve the dehydration rate.

According to the paper machine of the present invention as set forth in claim 4, the steam type heating means is provided with a steam box for guiding the supply of steam to the paper material layer, and the steam box has an opening at the tip. Rim Because the wire is placed in contact with or close to the wire, steam can be efficiently supplied to the paper stock layer.

According to the paper machine of the present invention, the sealing means for sealing the inside and the outside of the steam box is provided on the periphery of the opening of the tip of the steam box, so that the paper material layer can be more efficiently steamed. Can be supplied.

[0024] According to the paper machine of the present invention as set forth in claim 6, the sealing means is a sealing member attached to the periphery of the tip opening of the steam box and abutted against the wire. The steam can be efficiently supplied to the paper stock layer. According to the paper machine of the present invention as set forth in claim 7, the sealing means is provided on the upstream side in the traveling direction of the paper material layer with respect to the periphery of the tip opening of the steam box, and injecting the gas Since it is a gas injection device that suppresses the entrance of wake into the steam box, it is possible to more reliably inhibit the entrance of wake air into the steam box and efficiently supply steam to the paper stock layer. Can.

[0025] According to the paper machine of the present invention as set forth in claim 8, since the suction box sandwiches the paper material layer and sucks the steam jetted from the steam box on the opposite side to the steam box I The high temperature water condensed on the surface of the bed can be permeated to the inside of the paper stock layer. Thus, the entire paper material layer can be reliably heated and dewatered.

According to the paper machine of the present invention as set forth in claim 9, the downstream end of the paper material layer of the suction box in the traveling direction is disposed downstream of the downstream end of the steam box in the traveling direction. Therefore, the water content of the paper material layer in the temperature rising state can be further dehydrated, and the dehydration rate can be further improved.

[0026] According to the paper machine of the present invention as set forth in claim 10, on the other side of the paper material layer from the steam box and on the downstream side of the paper material layer in the running direction, According to the paper machine of the present invention, the suction force of the suction box on the downstream side in the traveling direction of the paper material layer can be further improved since the suction box is provided. Is set to be greater than the suction force of the upstream suction box V, so that the water in the paper material layer which has been heated by the upstream steam box is further dewatered. The dewatering rate can be further improved.

According to the paper machine of the present invention as set forth in claim 12, the inside of the steam box is divided into a plurality of sections in the width direction of the paper material layer, and the inside of the suction box corresponds to the division inside the steam box. As the paper material layer is divided into a plurality of sections in the width direction, it is possible to adjust the injection state of steam and the suction state of steam in each divided area unit in the steam box and in the suction box, so The dehydration rate can be adjusted in area units.

[0028] According to the paper machine of the present invention as set forth in claim 13, the steam supplied by the steam type heating means heats the paper material layer by acting as a collision jet on the paper material layer, so that the efficiency is improved. The paper material layer can be well heated and dewatered.

According to the paper machine of the present invention as set forth in claim 14, since the control means for automatically adjusting the adjustment means is provided, the steam supply state can be automatically adjusted.

[0029] According to the paper machine of the present invention as set forth in claim 15, the control means causes the steam to rise up to the target temperature based on the detection information by the raw material concentration detection means. Since the steam supply state by the heating method is controlled, the steam supply state can be adjusted to obtain the optimum dewatering efficiency.

According to the paper machine of the present invention as set forth in claim 16, as the heating means for heating the paper material layer on the downstream side in the traveling direction of the paper material layer from the installation location of the steam type heating means Since the air jet type calorific heating means for heating the paper raw material layer by the collision jet of high temperature air is provided, the temperature of the paper raw material layer heated in the steam type heating means is further heated and dewatered. The dewatering rate can be further improved.

[0030] According to the paper machine of the present invention as set forth in claim 17, as the heating means, the first heating means for heating from one side of the paper material layer, and the second one for heating from the other side of the paper material layer. Since the heating means and force are provided, both sides of the paper material layer can be uniformly dewatered. According to the papermaking method of the present invention as set forth in claim 18, the steam is supplied to the paper material layer at the heating target portion so that the paper material layer reaches the preset target temperature, and the paper material is extracted by the condensing action of the steam. Since the layer is heated and then water is absorbed and removed from the paper stock layer, it is possible to more efficiently heat the paper stock layer and dewater it. This can improve the dehydration rate. Brief description of the drawings

FIG. 1 is a block diagram schematically showing a papermaking machine as a first embodiment of the present invention.

2 (a) and 2 (b) schematically show a steam box and a suction box according to the first embodiment of the present invention, and FIG. 2 (a) is a cross-sectional view in the wet paper web traveling direction. Fig. 2 (b) is a sectional view taken along the line A-A of Fig. 2 (a).

FIG. 3 is a graph showing a change in dehydration rate (dehydration promoting effect) with respect to the raw material concentration of the wet paper according to the first embodiment of the present invention.

FIG. 4 is a schematic view showing a papermaking machine as a second embodiment of the present invention.

FIG. 5 is a block diagram schematically showing a papermaking machine as a third embodiment of the present invention.

FIG. 6 is a schematic view showing a papermaking machine as a fourth embodiment of the present invention.

[FIG. 7] A configuration view schematically showing a papermaking machine as a fifth embodiment of the present invention.

[Fig. 8] Figs. 8 (a) and 8 (b) schematically show a steam box and a suction box according to a conventional paper machine, and Fig. 8 (a) is a sectional view of the wet paper web traveling direction. Fig. 8 (b) is a cross-sectional view taken along the line A-A of Fig. 8 (a).

Explanation of sign

[0032] 1 Wet paper (paper material layer)

la pulp suspension (paper stock solution)

2 heads, hooks

3a, 3b wire

4 forming holes

5 Blades show

6,, 60 steam box (steam heating means)

6a Steam box body

6b thermal body

6c Seal member (seal means)

6d partition wall

6e steam supply room

6f steam inlet 6g tip opening

7, 7A, Ί ', 70 suction box

7d partition wall

7e suction chamber

7f suction port

7g tip opening

8 Sacion ronore

9 Suction Box

10 Steam sources

11 valve (adjustment means)

12 Controller (Control means)

13 Moisture content sensor (raw material concentration detection means)

14 Gas injection device (seal means)

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[1] First Embodiment

1 to 3 are for describing a paper machine as a first embodiment of the present invention, and FIG. 1 is a schematic view schematically showing the paper machine, and FIGS. 2 (a) and 2 (b) are FIG. 2 (a) is a cross-sectional view in the traveling direction of the wet paper web, and FIG. 2 (b) is a cross-sectional view taken along the line A-A of FIG. Is a graph showing the change of the dewatering rate (dewatering promoting effect) with respect to the concentration of the raw material of wet paper.

In this paper machine, as shown in FIG. 1, a twin wire former is adopted, and when the pulp suspension liquid (paper material liquid) la is jet-supplied between the wires 3a and 3b by the head box 2. These are held in layers between the wires 3a and 3b, and are in the state of a wet paper (paper material layer) 1, and the wet paper 1 is dewatered by means of tension of the wires 3a and 3b. It is designed to be dewatered by a blade shoe 5 or the like that dewaters by curving.

Here, on the downstream side of the blade shoe 5, the wet paper web 1 is heated by the steam box 6 and a suction bag installed so as to sandwich the steam box 6 and the wet paper web 1. It is sucked by Tas 7 and dehydrated. Here, the steam box 6 and the suction box 7 according to the present embodiment will be described in more detail.

As shown in Fig. 2 (a) and Fig. 2 (b), the steam box (steam heating means) 6 as heating means comprises a steam box main body 6a, a heat insulator 6b and a sealing member (seal means) 6c. Is configured.

The steam box body 6a has a machine length of, for example, about 100 to 1000 mm in the traveling direction, and the inner space is divided into a plurality of steam supply chambers 6e by partition walls 6d in the wet paper web 1 width direction. In each steam supply chamber 6d divided by the partition wall 6d, a steam inlet 6f for taking in steam from the steam generation source 10, and a tip opening 6g on the surface facing the wire 3a are formed. There is. In the present embodiment, a seal member 6c is provided at the tip opening 6g of the steam box main body 6a, and the seal member 6c is in contact with the wire 3a.

Further, by supplying the steam from the steam generation source 10 to each steam supply chamber 6e, the temperatures of the wires 3a and 3b and the wet paper web 1 can be heated to about 40 to 100 ° C. . The supplied steam can also act on the wet paper 1 as a collision jet, so that the wet paper 1 can be heated efficiently.

The heat retaining body 6b is, for example, a heat retaining structure having a heat insulating material or a heat insulating layer, or a heating device such as an electric heater, a heating steam jacket, a high temperature air jacket, etc., attached to the outer wall of the steam box main body 6a. It is designed to keep you warm. Thus, it is possible to prevent steam condensation and dew condensation on the inner wall surface of the steam box body 6a (ie, the inner wall surface of the steam supply chamber 6e).

[0038] The seal member 6c is attached to the periphery of the tip opening 6g of each steam supply chamber 6e so as to abut on the wire 3a, and functions to seal the inside and outside of the steam box body 6a and each steam supply chamber 6e. doing. Thereby, the airtightness inside the steam box body 6a and the inside of each steam supply chamber 6e is secured. From the viewpoint of sealability, for example, an elastic material such as rubber is suitable for the sealing member 6c, and heat resistance is also required, and a heat resistant material such as Bakelite is also suitable. Of course, materials having both heat resistance and elasticity such as heat resistant rubber are more preferable.

[0039] In the case where the seal member 6c is present, the wake from the gap between the wire 3a and the upstream side of the tip opening 6g. There is a risk that the steam will not be in contact with the wet paper 1 due to the ingress of air, but by equipping the above-mentioned seal member 6c, the vapor contacts the entire wet paper 1 in each steam supply chamber 6e reliably. It can be done. That is, it is possible to prevent the efficiency of condensation of vapor from adhering to the wet paper 1 (condensation and adhesion efficiency) being reduced.

A valve (adjusting means) 11 is provided for each supply pipe connected to each steam supply chamber 6 e, and the steam supplied to the steam box 6 is supplied from the steam generation source 10 to these valves 11. It comes to be supplied via. Further, by controlling the opening / closing operation of each nose 11 with the controller 12, the amount of steam supplied in the steam supply chamber 6e can be adjusted separately. The steam referred to in the present embodiment may be any of saturated steam, heated steam, and moist air.

The suction box 7 has, for example, the same length as the steam box 6 or a shorter length than the steam box 6, and has an inner space in the width direction of the wet paper web 1, and the same as the steam box main body 6 a It is divided into a plurality of suction chambers 7e by partition walls with a width. In each suction chamber 7e divided by the partition wall 7d, a suction port 7f connected to a suction device (not shown) and a tip end opening 7g are formed on the surface facing the wire 3b. Furthermore, the suction box 7 is installed so that the end opening 7g abuts on the surface of the wire 3b.

Generally, the force is set with equal width between the steam box 6 and the wires 3a, 3b. For example, when the width of the steam box 6 is larger than the width of the wires 3a, 3b, the exposed portion of the tip opening 6g In order to prevent steam from leaking as a component, it is preferable that a member that abuts (or is close to) the exposed portion to prevent steam from leaking is provided. In the present embodiment, the width of the suction box 7 is formed to be substantially equal to the width of the steam box 6, and the suction box 7 functions as the above member.

The wet paper web 1 is heated and heated and dewatered by the steam box 6 and the suction box 7 as described above. Specifically, the steam supplied into the steam box 6 condenses on the surface of the wire 3a and the surface of the wet paper 1 to become high temperature water. Then, high temperature water enters the inside of the wet paper 1 by the suction function of the suction box 7, and the heat transfer of the high temperature water heats the entire wet paper 1 and the water inside the wet paper 1 is sic The wet paper web 1 is dewatered by suction. Further, the temperature rising process is in progress in such a steam box 6, and the wet paper web 1 entering the steam box 6 is gradually heated up in the steam box 6, but the whole wet paper web 1 is There is a delay in raising the temperature. Therefore, in this paper machine, as shown in FIG. 1, the wet paper web 1 in a state in which the temperature is increased in the steam box 6 and the dewatering effect has become high is a suction roll 8 installed on the downstream side of the steam box 6 It is designed to be further dehydrated by 9. Thereby, dehydration can be performed more efficiently, and the dehydration rate can be improved.

By the way, as described above, the present inventors have found that even if the amount of supplied steam is increased to further increase the dehydration rate, the dehydration rate may be reduced. This is thought to be because when the amount of steam supply is increased, the amount of heat supplied can be increased, while the amount of water condensed increases, leading to an increase in the moisture content. It is important how to set the amount.

Therefore, it was examined how the dewatering rate changes in accordance with the paper material concentration of the wet paper 1 under a constant suction condition. The results are shown in Figure 3.

FIG. 3 shows the dewatering improvement characteristics due to the temperature rise effect when the steam supply amount is large and when the steam supply amount is small, and the dewatering reduction characteristics due to the dewatering resistance when the suction pressure is constant.

For example, as shown by lines Ml and M2 in FIG. 3, the characteristics of the dewatering acceleration effect by steam supply indicate that as the raw material concentration is higher, the amount of moisture is smaller and the amount of moisture is smaller as shown by lines Ml and M2 in FIG. Since the mass of the paper 1 is low, the heat capacity decreases, and the temperature rise of the wet paper 1 increases, and the dewatering rate increases (that is, the temperature increase effect of the wet paper 1 increases the dewatering rate). The lines Ml and M2 are compared, but it goes without saying that the dewatering rate is higher in the case of large steam supply (Ml) than in the case of small $ and case (Μ2).

On the other hand, when the suction pressure is constant, as shown by line S in FIG. 3, the characteristic of the dehydration promoting effect by suction is that the higher the raw material concentration, the larger the dehydration resistance, and the dehydration rate is It gets lower.

Therefore, when the steam supply is large, the property of the substantial dehydration promotion effect is the sum of the dewatering acceleration effect by the steam supply shown by line Ml and the dehydration acceleration effect by suction shown by line S, This dehydration promoting effect is shown by line L1 in FIG. It will have a mountain-like characteristic of rising to a certain raw material concentration and then falling gradually.

[0049] Similarly, when the amount of steam supply is small, the characteristics of the substantial dewatering promoting effect are the dewatering promoting effect by the steam supply shown by this line M 2 and the dewatering promoting effect by the suction shown by line S. And a line L2.

In general, the dehydration rate V corresponding to the dehydration improvement rate is expressed by the equation (1) according to the Darcy rule.

[Number 1] 厶 P

(1)

(R _mat + 2 Rw) μ

However, ν: dehydration speed

Δ Ρ: Upper and lower differential pressure

R _mat : wet paper dewatering resistance coefficient

R w: wire dewatering resistance coefficient

μ: water viscosity

In this equation (1), the upper and lower differential pressure ΔΡ, the wet paper web dewatering resistance coefficient R, the wire dewatering resistance coefficient mat

Assuming that R is constant and focusing on the relationship between the dehydration rate V and the water viscosity, the dehydration rate V is in inverse proportion to the water viscosity. Also, there is a relationship between the water viscosity and the wet paper temperature that the water viscosity decreases as the wet paper temperature increases. That is, there is a relation that the dewatering speed V increases as the temperature of the wet paper increases.

Usually, according to the Darcy's law, the temperature of the wet paper 1 is increased by heating steam, so that the dewatering rate is increased and the dewatering rate is increased. However, the dewatering rate is increased as the raw material concentration is increased. As the resistance increases, it becomes a mountain-like characteristic as shown in Fig. 3, and there is the raw material concentration that corresponds to the efficiency of the steam supply condition.

Therefore, in order to improve the dewatering rate, it is preferable to set the optimum vapor supply amount in accordance with the raw material concentration of the wet paper 1 in consideration of such characteristics. Therefore, in the paper machine, as shown in FIG. 1, a position corresponding to the position of each steam supply chamber 6e in the width direction of the wet paper web 1 in the width direction of the wet paper web 6 A moisture sensor (raw material concentration detection means) 13 for detecting the moisture content of the wet paper 1 (corresponding to the raw material concentration, the raw material concentration (%) = 100-moisture rate (%;)) (Only one is shown in Figure 1). Then, the controller 12 causes the temperature of the wet paper 1 passing through each of the steam supply chambers 6 e to reach the target wet paper temperature (the target temperature set in advance to correspond to the material concentration of the wet paper 1). In addition, based on the detection information from each water content sensor 13, the opening and closing operation of each valve 11 is adjusted to control the steam supply state of each steam supply chamber 6e in real time. For example, assuming that the steam supply chamber 6e is disposed at a certain point and the reference material concentration of the wet paper web 1 entering this point is 12%, the material concentration of the wet paper web 1 is 10% by the moisture content sensor 13. If detected, controller 12 controls valve 11 to increase the amount of vapor supplied, and if moisture content sensor 13 detects that the material concentration of wet paper 1 is 14%, controller 12 controls the vapor Control valve 11 to reduce the supply rate.

In addition, since the injection state and the suction state of steam can be adjusted in units of divided areas in steam box 6 and suction box 7, dewatering adjustment in the width direction of wet paper 1 can be easily performed. be able to.

Furthermore, since the steam is supplied to the wet paper web 1 via the wire 3a, the edge of the tip opening 6g of the steam box 6 and the wet paper web 1 coming into contact with each other do not break the wet paper web 1 It is possible to prevent deterioration or discoloration of the pulp caused by direct contact of the high temperature steam with the wet paper 1. That is, in the case of the conventional structure in which the wet paper web 1 is sprayed with steam directly, it is necessary to provide a space between the steam box 6 and the wet paper web 1 so as not to damage the wet paper web 1. However, since this paper machine uses twin wires that support both sides of the wet paper 1 with the wires 3a and 3b, the wet paper 1 may not be damaged by bringing the steam box 6 into contact with the wire. Therefore, the above-mentioned gap can be eliminated, and the amount of vapor release can be suppressed as compared with the prior art. That is, the loss of steam can be prevented, and the supplied steam can be efficiently used.

Further, since the sealability within the steam box 6 is ensured by the seal member 6c of the steam box 6, the steam discharge to the outside of the internal force of the steam box 6 can be further suppressed.

Furthermore, conventionally, attention is paid to the fact that the temperature of the wet paper web 1 is increased for dewatering by permeating the steam inside the wet paper web 1, and the state in which the steam easily penetrates, ie, the final part of the former The steam box 60 and the suction box 70 are positioned at a position where the wet paper 1 is in a porous state or in a state where a void is formed, “before the completion of the dewatering” of the wet paper 1 in FIG. b) had to be installed. On the other hand, in this paper machine, the suction action of the suction box 7 Paper 1 Because attention is paid to the point that the temperature of the wet paper 1 is increased by dewatering by replacing the high temperature water condensed near the surface of the wet paper 1 with the moisture inside the wet paper 1 as in the prior art. Need to infiltrate the steam.

That is, while the steam box had to be installed at the position before the completion of dehydration (that is, near the outlet of the former), according to the present invention, it can be installed further upstream. It is. This makes it possible to promote the dewatering of the wet paper web 1 in the former by the upstream force. In this paper machine, as described above, the optimal steam supply is performed according to the raw material concentration state of the wet paper 1, so that the heating and dewatering efficiency can be enhanced. Therefore, it becomes possible to perform dewatering in the form extremely efficiently, which in turn makes it possible to form the foam in the form of a foam, and also has the effect of reducing the installation space of the foam.

Further, the heat transfer efficiency by steam condensation of this paper machine is about 25 times the heat transfer efficiency by the conventional steam permeation, and it is very high efficiency as compared with the conventional one. Therefore, the temperature rise of the wet paper web 1 has been insufficient in the past, and even if the suction box 9 is installed downstream of the suction box 70, the dewatering effect can not be obtained. Since the paper 1 is sufficiently heated, a high dewatering effect can be obtained by the suction roll 8 on the downstream side of the suction box 7 downstream, and it is possible to accelerate the dewatering of the wet paper 1. It is.

In the present embodiment, the internal space of the steam box 6 and the suction box 7 is divided, and the injection state of the steam and the suction state of the steam are adjusted in each divided area unit. If the raw material concentration difference in the width direction can be ignored, these internal spaces may not be divided (that is, the partition walls 6d and 7d are not provided). Also, in this case, the representative raw material concentration (for example, the center in the width direction of the wet paper) is obtained from each moisture content sensor 13 and the vapor supply state necessary to raise the temperature to the target wet paper temperature based on this representative raw material concentration. May be set. Alternatively, the moisture content sensor 13 is installed at only one location in the width direction of the wet paper web (for example, in the central portion in the width direction of the wet paper web 1), and based on the material concentration obtained from the moisture content sensor 13 up to the target wet paper temperature The steam supply condition required to raise the temperature may be set.

Furthermore, in the present embodiment, the controller 12 is configured to automatically adjust the opening / closing operation of the valve 11 based on the detection information from the moisture content sensor 13. The operator may manually perform the valve opening / closing operation based on the detection information of Further, in the present embodiment, the steam box 6 and the suction box 7 are provided as a former for forming the paper layer, but the press part on the downstream side of the former (the paper material layer formed with the former is added Of course, it may be suitable for the part that further dehydrates by pressing

[2] Second Embodiment

Next, a paper machine as a second embodiment of the present invention will be described.

As shown in FIG. 4, in addition to the configuration of the first embodiment, the present paper machine is configured to further include another suction box 7A at an adjacent position on the downstream side of the suction box 7.

As described in the first embodiment, the temperature rising process is in progress in the steam box 6, and the wet paper web 1 entering the steam box 6 is gradually heated in the steam box 6, but it is wet There is a delay before the entire paper 1 is heated. Therefore, in this paper machine, the wet paper web 1 in a state in which the temperature is increased in the steam box 6 and the dewatering effect is high is further dewatered by the suction box 7A. In addition, since the suction box 7A sucks the wet paper 1 in a highly dewatered state, it is possible to perform further dewatering even if the suction force of the suction box 7 is equal to that of the suction box 7A. It is preferable to set the suction force larger than the suction force of the suction box 7. Thereby, dehydration can be performed more efficiently, and the dehydration rate can be improved.

[3] Third Embodiment

Next, a paper machine according to a third embodiment of the present invention will be described.

As shown in FIG. 5, in the configuration of the first embodiment, the downstream end of the suction box 7 is disposed downstream of the downstream end of the steam box 6 in the configuration of the first embodiment. It is configured.

As described above, there is a delay before the entire wet paper web 1 is heated by the steam box 6. Therefore, it is possible to more efficiently wet the web by arranging the suction box 7 downstream. 1 can be dewatered, and the dewatering rate can be further improved.

In the present embodiment, the predetermined distance to the downstream side of the suction box 7 according to the first embodiment The upstream end of the suction box 7 according to the first embodiment is fixed at the same position, and only the downstream end of the suction box 7 is disposed. It may be configured to be located downstream of the downstream end.

[4] Fourth Embodiment

Next, a paper machine according to a fourth embodiment of the present invention will be described.

As shown in FIG. 6, in the configuration of the first embodiment, the present paper machine is provided with a gas injection device (seal means) 14 for injecting gas toward the upstream side near the upstream end of the steam box 6. Is configured. In addition, it is preferable that the gas injection device 14 injects the gas toward the upstream side at an injection angle 対 of about 15 to 40 ° to the wet paper.

This makes it possible to more reliably suppress the entry of wake air into the steam box 6. When the wake air can be sufficiently suppressed by the gas injection device 14, the seal member 6 c on the upstream side of the steam filter 6 may be omitted.

[5] Fifth Embodiment

Next, a paper machine according to a fifth embodiment of the present invention will be described.

As shown in FIG. 7, the paper machine is configured by including two units of the steam box 6 and the suction box 7 according to the first embodiment. Specifically, a unit of steam box 6 (first heating means) 6 and suction box 7 and a steam box (second heating means) 6 ′ and a suction box are provided. In addition to supplying steam to one side of the wet paper web 1, steam is also supplied to the other side of the wet paper web 1 by a steam box. As a result, both surfaces of the wet paper web 1 can be dewatered uniformly, and it becomes possible to produce a product with both front and back differences uniform on both surfaces.

[6] Others

The embodiment of the present invention has been described above, but the present invention can be variously modified and implemented without departing from the spirit of the present invention, which is not limited to the above embodiment.

Generally, the installation position of the steam box 6 is determined in advance by design. The material concentration (reference material concentration) of the wet paper 1 at this installation position can also be predicted at the design stage. Steam supply is performed to achieve the target wet paper temperature corresponding to the standard raw material concentration. You should be In the present embodiment, when the moisture content sensor 13 detects the actual raw material concentration state of the wet paper 1, and the raw material concentration of the wet paper 1 passing through the steam box 6 deviates from the above-mentioned reference raw material concentration, In order to correct this deviation, it was configured to adjust the vapor supply amount of the vapor box 6 by feedback control, but when such deviation of the raw material concentration can be almost ignored, the moisture content sensor 13 is not Make sure to configure the loop to supply constant steam at all times.

In addition, means for detecting the temperature of the wet paper 1 may be provided, and the feedback control based on the detection information may adjust the steam supply so that the wet paper 1 has the target wet paper temperature. Even in this case, the wet paper web 1 can be efficiently heated and dewatered, and the dewatering rate can be improved.

In addition, on the downstream side of the steam box 6, an air jet heating unit may be provided which heats the wet paper 1 by blowing hot air onto the wet paper 1 and using a collision jet of the high temperature air. By configuring in this manner, the temperature of the wet paper web 1 that has been raised in temperature by the steam box 6 can be further raised, and it is possible to improve the dewatering efficiency by the success roll 8 or the suction box 9 or the like. Become

Further, steam box 6 is preferably installed in a former having a high moisture content of wet paper 1 because the effect is high when the moisture content of wet paper 1 is high, but the upstream part of the press part (near the inlet) It may be installed in In addition, it is preferable to install the air jet heating means in the press part where the moisture content of the wet paper 1 is lower than that of the wet paper 1 in the former and the effect is high when used in a state. However, it may be installed downstream of the former (near the outlet).

Further, in the above-described embodiment, if the sealing property of the force steam box 6 configured to contact the sealing member to the wire 3 a in order to ensure the sealing property of the steam box 6 can be secured, The sealing member 6c may be configured to be close to the wire 3a. In addition, the sealing member 6c may not be provided, as long as the airtightness of the inside of the steam box 6 can be secured by bringing the tip opening 6g of the steam box 6 into contact with or close to the wire 3a.

Further, the present invention is not necessarily limited to the twin wire, and may be a long mesh type former or an on top former which holds only one side of the paper material layer. Industrial applicability

The present invention can be applied to a paper machine and a paper making method in which paper stock is carried out by holding the paper stock solution in layers and removing water while running the paper stock layer.

Claims

The scope of the claims

[1] In a paper machine, in which the paper material solution jetted from the head box is held in layers and the paper material layer is not moved.

The above-mentioned part for removing water is provided as a heating means for heating the paper material layer to promote the water removal, and the paper material layer is supplied with steam and condensed by the steam. Steam heating means for heating;

According to the raw material concentration state of the paper material layer at the time of passing through the steam type heating means so as to bring the paper material layer to a preset target temperature An adjustment means for adjusting is provided.

A paper machine characterized by

[2] The water removing part described above is a former that holds the paper material solution jetted from the head box in layers and dehydrates water while running the paper material layer to form a paper layer, or the former It is a press part that pressurizes the paper material layer on which the paper layer is formed to further dehydrate it.

The paper machine according to claim 1, characterized in that.

[3] The forming part is configured as a twin wire former having wires on both sides of the paper material layer

A paper machine according to claim 2, characterized in that.

[4] The steam heating means is provided with a steam box for guiding the supply of steam to the paper material layer, and the steam box causes the opening edge of the tip to abut or approach the wire. Is placed

A paper machine according to claim 3, characterized in that.

[5] Sealing means for sealing the inside and the outside of the steam box is provided on the periphery of the opening of the tip of the steam box

A paper machine according to claim 4, characterized in that.

[6] The sealing means is a sealing member attached to the periphery of the tip opening of the steam box and in contact with the wire.

A paper machine according to claim 5, characterized in that.

[7] The sealing means is provided on the upstream side in the traveling direction of the paper material layer with respect to the periphery of the tip opening of the steam box, and injecting the gas into the vapor box of the wake of the paper material layer. Is a gas injection device that suppresses the entry of

A paper machine according to claim 5, characterized in that.

[8] A suction box is provided on the side opposite to the steam box across the paper material layer, for suctioning the steam injected from the steam box.

The paper machine according to any one of claims 4 to 7, characterized in that.

[9] The downstream end of the paper material layer in the traveling direction of the suction box is disposed downstream of the downstream end of the traveling direction of the steam box.

A paper machine according to claim 8, characterized in that.

[10] Another suction box is provided on the other side of the paper material layer opposite to the steam box and downstream of the paper material layer in the running direction. 10. A paper machine according to claim 8 or 9, characterized in that.

[11] The suction force of the suction box on the downstream side of the paper material layer in the traveling direction is set larger than the suction force of the suction box on the upstream side.

11. A paper machine according to claim 10, characterized in that.

[12] The inside of the steam box is divided into plural in the width direction of the paper material layer, and the inside of the suction box is plurally in the width direction of the paper material layer so as to correspond to the division in the steam box. Divided,

It is possible to adjust the injection state of the steam and the suction state of the steam in each divided area in the steam box and in the suction box.

A paper machine as claimed in any one of claims 8-11, characterized in that.

[13] The steam supplied by the steam heating means heats the paper material layer by acting on the paper material layer as a collision jet.

A paper machine as claimed in any one of claims 1 to 12, characterized in that.

[14] A control means for automatically adjusting the adjusting means is provided.

A paper machine as claimed in any one of claims 1 to 13, characterized in that.

[15] A raw material of the paper material layer when passing through the steam-type heating means in the vicinity of the steam-type heating means Means for detecting raw material concentration are provided;

The control means controls the steam supply state by the steam type heating means so that the paper material layer is heated up to the target temperature based on the detection information by the raw material concentration detection means. A paper machine according to item 14.

[16] High-temperature air is blown to the paper material layer as heating means for heating the paper material layer on the downstream side in the traveling direction of the paper material layer than the installation location of the steam type heating means The paper machine according to any one of claims 1 to 15, further comprising an air jet heating means for heating the paper material layer by jet flow.

[17] As the heating means, a first heating means for heating from one side of the paper material layer, and a second heating means for heating from the other side of the paper material layer are provided

A paper machine as claimed in any one of the claims 1 to 16, characterized in that.

[18] In a papermaking method, papermaking is carried out by holding the paper stock solution jetted from the head box in a layered manner and running this paper stock layer.

Steam is supplied to the paper material layer at the heating target location so that the paper material layer reaches a preset target temperature, and the paper material layer is heated by the condensation action of the steam, and then the paper material Absorb and remove moisture from the layer

A papermaking method characterized by