JPH0247385A - Apparatus for removing liquid of web - Google Patents

Abstract

PURPOSE:To increase the amount of removed water per heating roller and enable simple regulation of even the state of removed water by providing plural pressing means in one heating roller so as to enable regulation of intervals therebetween. CONSTITUTION:Plural pressure contact rollers 13 and 13 for pressing a wet paper 1 to a heating roller 12 and a conveyor belt 11 for carrying and conveying the wet paper are provided for the one heating roller 12 so as to enable regulation of the mutual intervals therebetween.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is a porous wet web, for example, a method for removing liquid components such as water impregnated into a thin ant-like web such as thin printing paper during the manufacturing process of the web. The present invention relates to a device for removing liquid from a web to be removed.

[Conventional technology] FIG. 8 is a schematic diagram showing a part of a conventional paper making line.

The web 1 formed through the head box and the wet part is dehydrated in the press part 2 and drying part 3, and then finished in the calender part 4 to become a product. In the drying part 3, the web 1 is brought into contact with the cylindrical dryer cell 5 heated by blowing steam, and the web temperature is gradually increased to evaporate and remove moisture. The web moisture content at the entrance of drying part 3 is 50% to Bθ%, and the web moisture content at the exit of drying part 3 for converting web 1 into products is 7%.
It is. Therefore, the moisture content of web 1 is 50% to BO%.
The number of dryer cells 5 required to reduce the amount from
In general, it is 50 to 70 trees, and the line length of drying part 3 is also 50 to 3L? Om is required.

USP4 is a technology that is considered useful for shortening the line length in the conventional drying part 3 above.
There is a moisture removal device according to No. 324813. This moisture removal device allows a web conveyed by felt to pass through a nip region between a pair of heating rollers and an air permeable roller. The heated rollers of the moisture removal device deliver heat under high contact pressure to the web passing through the nip area, causing the moisture in the web to rapidly convert to steam, which penetrates the web and remains in the web. This results in the free water being carried out to the felt side. Therefore, it seems that this moisture removal device has good moisture removal efficiency and can shorten the line length of the drying part 3 described above.

[Problem to be solved by the invention] However, according to the inventor's consideration, the above USP 4
In the moisture removal device of No. 324813, the heating roller and the permeable roller form only one nip area, and the amount of moisture removed per heating roller is relatively small, and the moisture removal state cannot be adjusted. is also difficult.

According to the inventor's experiments, if the moisture generated at the boundary with the heating roller evaporates too quickly,
It has also been recognized that it is important to adjust the pressure conditions in the nip area formed around the heating roller, as the generated steam may damage the web.

The present invention increases the amount of liquid removed per heating roller, and also allows the state of liquid removal to be easily adjusted, thereby improving the efficiency of liquid removal.

The purpose is also to improve the workability of liquid removal.

[Means for Solving the Problems] The present invention according to claim 1 includes a transfer belt that is provided with a porous support surface and that supports and transfers a web on the support surface;
A heating roller that rotates in thermal contact with the web supported on the transfer belt, and a nip that presses against the back side of the web-supporting surface of the transfer belt and pinches the transfer belt and the web between the heating roller and the heating roller. the heating roller delivers heat under high contact pressure to the web passing through the nip region, rapidly converting the liquid in the web into vapor, which vapor is In a web liquid removal device configured to penetrate the web and carry out free liquid remaining in the web to the side of a porous support surface of a transfer belt, each of a plurality of pressure welding devices is connected to a heated roller. A nip position adjustment device is provided at each position along the outer periphery to adjust the distance between the nip regions formed by the pressure welding devices.

The present invention according to claim 2 provides a web line upstream side with respect to a nip area formed by the heating roller and the pressure contact device,
A web preheating device is arranged to preheat the entire web from both the front and back sides of the web.

According to the present invention as set forth in claim 1, (1) the plurality of pressure welding devices form a plurality of nip regions for one heating roller, and the transfer belt stretched between the two pressure welding devices; Based on the tension, the web is pressed between the web and the heating roller to form a quasi-nip region that performs substantially the same liquid removal action as in the above-mentioned nip region. Therefore, the liquid content in the web is evaporated by the thermal energy of a single heating roller, and the liquid content removed by the vapor carrying away the free liquid in the web, in the multiple nip regions and the quasi-knee twop region. As a result, 1
The amount of liquid removed per heating roller becomes large, and the efficiency of liquid removal can be improved.

In addition, the nip position adjustment device can adjust the spacing between the nip regions formed by each pressure welding device. Therefore, the timing of the liquid removal action that each nip region exerts on the web, the length of the quasi-nip region (time ), the liquid removal state can be easily adjusted, such as by adjusting the pressing force state of the nip area and the semi-nip area formed around the heating roller, and the workability of liquid removal can be improved.

According to the second aspect of the present invention, the web whose entire surface including the front and back sides has been preheated by the web preheating device is introduced into the nip region between the above-mentioned heating roller and each pressure contact device.

Therefore, ■The preheating device can preheat the liquid in the web until just before evaporation, and the thermal energy of the heating roller can be used more effectively for rapid and explosive vapor conversion. The device can raise the temperature of the liquid in the web to lower its viscosity (resistance to liquid removal), and the resistance to conveying the liquid due to vapor generated by the heating roller can be reduced in advance. That is, (1) and (2) effectively complement the liquid removal effect according to the present invention as set forth in claim 1 above.

[Example] Fig. 1 is a schematic diagram showing a moisture removing device according to an embodiment of the present invention, Fig. 2 is a schematic diagram showing an enlarged main part of the moisture removing device, and Fig. 3 is a heating roller. A schematic diagram, FIG. 4 is a schematic diagram showing an example in which the present invention is applied to a paper making line, FIG. 5 is a schematic diagram showing another example in which the present invention is applied to a paper making line, and FIG.
The figure is a diagram showing the water removal effect of the present invention.

As shown in FIG.
1. Heating roller 12. It is configured with a pressing roller 13 (pressing device), and removes moisture from the web l guided and conveyed by a transfer roller 14.

The transfer belt 11 is made of a perforated steel belt, a glass fiber belt, a carbon fiber belt, etc.
A porous support surface 11At is provided, and a transfer bell (transfer bell) 11 supports and transfers the web l on the support surface 11A (see FIG. 2). wrapped around. The transfer belt 11 has a function of absorbing water in the web, a function of smoothing the surface of @Uni 1, and a function of withstanding tension.

The heating roller 12 rotates in thermal contact with the web 1 carried by the transfer belt 11. Here, the heating roller 12 of this embodiment is configured as shown in FIG. 3, and the roller body 18 is supported by a bearing 17 provided on the machine base 15, and the roller body 18 can be rotated by a drive motor (not shown). It is said that The roller body 18 supports a fixed shaft 20 in a stationary state via a bearing 19 therein, and is composed of an iron core 21 formed by a part of the fixed shaft 20 and an induction coil 22 wound around the iron core 21. It has a built-in magnetic flux generating section 23. The magnetic flux generating section 23 generates magnetic flux for inductively heating the roller body 18. The heating roller 12 also has an airtight chamber 18A within the thickness of the dark wall portion of the roller body 18, in which a heat medium (water, oil, etc.) is sealed in a vacuum state.

The pressure roller 13 is in pressure contact with the back surface of the supporting surface 11A of the transfer belt 11 that supports the web l, and has a nip area N between it and the heating roller 12 that pinches the transfer belt 11 and the web l.
form 1. Here, the moisture removal device IO of this embodiment has a pair of support stands 24 on both sides of the lower part of the heating roller 12 on the machine base 15, and each pressure roller 13 is rotatable on a bearing 25 provided on each support stand 24. By supporting the heating roller 12, two pressure rollers 13 are respectively installed at two positions along the outer periphery of the heating roller 12. In addition, each pressure roller 13 is additionally equipped with a knob position adjustment device on an adjustment screw 26 that can adjust the position of the bearing 25 with respect to the support base 24. The distance between the nip regions N1 can be adjusted. Note that a pressure adjustment cylinder 27 (a tongue pressure adjustment device) is interposed between the support base 2"4 of each pressure roller 13 and the machine base 15, and
The nip pressure between the two can be adjusted as appropriate.

Furthermore, in the moisture removal device 10, the heating roller 12
A web preheating device 28 for preheating the entire web 1 from both the front and back surfaces of the web 1 is disposed upstream of the web line with respect to the nip area N1 formed by the pressure rollers 13 and 13. The web preheating device 28 is composed of microwave, far/near infrared heaters, etc., and as shown in FIG. 1, it is constructed by supporting upper and lower heaters 29A and 29B on the machine stand 15 in an openable/closeable state. 30 is a heater opening/closing cylinder.

Therefore, the moisture removing device 10 is installed, for example, in the drying part 3 of the paper making line, as shown in FIG.
It is used by installing a set of heating rollers 12 and pressure rollers 13, and one web preheating device 28. As shown in FIG. 5, this usage mode includes a mode in which two sets of heating rollers 12 and a pressure roller 13 are installed in addition to one web preheating device 28, or a mode in which one or more sets of heating rollers 12 and pressure rollers 13 are installed without using the web preheating device 28. Various modifications can be made, such as by installing rollers 12 and pressure rollers 13.

Next, the operation of the above embodiment will be explained.

(2) According to the above embodiment, the heating roller 12 receives the magnetic flux generating portion 23 by applying the AC voltage to the induction coil 22.
A current is induced by the alternating magnetic flux caused by the roller body 1B.
While generating heat in the peripheral wall of the roller body 18, the airtight chamber 18A acts like a heat pipe to uniformize the temperature of the peripheral wall of the roller body 18, and as a result, the surface temperature is constantly maintained at a uniform high temperature state. becomes.

Therefore, even when a web l with varying heat loads enters, the heating roller 1
2 comes into close contact with the web 1 with high contact pressure in the nip area Nl formed with the pressure roller 13, and heats the web 1 thoroughly and intensely at all times without lifting the web 1 from the heating roller 12.

This causes the moisture in the web to be very rapidly (explosively) converted to steam at the interface with the heating roller 12, which steam transfers the free water in the web onto the porous support surface 11A of the transfer belt 11. A large amount will be transported to the side. In addition,
The steam generated at the interface with the heating roller 12 as described above dissipates into the atmosphere at the exit side of the heating roller 12 where the web 1 is released from the nip region Nl. In Figure 2, W
is moisture, F is fiber, A is air, and ■ is vaporized moisture.

Therefore, according to the above embodiment, the water removal efficiency is extremely good, and the desired water removal work can be achieved with a small equipment space.

■Also. According to the above embodiment, ■2 wooden pressure rollers 13;
However, there are two nip areas N for one heating roller 12.
At the same time, the transfer belt 11 stretched between the repressing rollers 13 also pinches the web l between it and the heating roller 12 based on its tension, thereby forming the above-mentioned nick area M.
A quasi-nip area N2 is formed which performs substantially the same moisture removal action as in the area N2. Therefore, the water removal effect due to the evaporation of water in the web by the thermal energy of the single heating roller 12 and the transport of free water in the web by this steam is as follows.
This is done in multiple nip areas N1 and semi-nip area N2, and as a result, one heating roller 12
The amount of water removed per unit becomes large, and the water removal efficiency can be improved.

Furthermore, the distance between the nip regions N1 formed by the pressure rollers 13 can be adjusted by the adjustment screw 26 as a knee and push position W adjustment device. Therefore, the timing of the moisture removal action exerted on the web l by each nip region N1,
The length (time) of the quasi-nip area N2 can be adjusted, and the nip area N formed around the heating roller 12
The water removal state can be easily adjusted by adjusting the pressurizing force state of N1 and the quasi-nip region N2, and the workability of water removal can be improved.

In addition, in the moisture removing device 10, the heating roller 1
2 has a built-in heating source (in this case, the heating source is not limited to an induction heating method, but may be other means such as a resistance wire heating method), and there is no heating source attached around it. Two or more pressure rollers 13 can be easily installed in a wide range around the heating roller 12, and the mutual spacing between the rollers 13 can be adjusted in a wide range.

(2) Further, in the above embodiment, the web l whose entire surface including the front and back sides has been preheated by the web preheating device 28 is introduced into the nip area Nl between the heating roller 12 and each pressure roller 13 described above. Therefore, (1) the preheating device 28 can preheat the moisture in the web until just before evaporation, and the thermal energy of the heating roller 12 can be used more effectively for rapid and explosive steam conversion; (2) The preheating device 28 can raise the temperature of the water in the web to lower its viscosity (resistance to dewatering), and the resistance to water removal due to steam generated by the heating roller 12 can be reduced in advance. That is, (1) and (2) effectively complement the water removal effect of the present invention described above.

According to the experimental results on the paper making line shown in FIG. 4, when the web conveyance speed is t5 om/min,
The relationship between the incoming nib moisture Win and the outgoing nib moisture Wout was as shown in FIG. In other words, while the entering row nib moisture is 51%, the exit web moisture is 24%.
The total length 3L of the drying part 3 was reduced from the conventional 50 to 70 m to 30 to 48 m. That is, it has been confirmed that the number of conventional dryer cells can be reduced by 50 to 30%, and the equipment space can be reduced by 40 to 20% compared to the conventional method.

Further, in the paper making line shown in FIG. 5, the total length 3L of the drying part 3 could be shortened to 10 to 15 m. Note that in FIGS. 4 and 5, IOL is the entire length of the water removal device 10.

FIG. 7 is a schematic diagram showing another embodiment of the present invention. 7th
In the figure, 12 is a heating roller having the same structure as in the embodiment shown in FIG. 1, and 13 is also a pressure roller, which is the same as in the embodiment. This embodiment differs from the embodiment shown in FIG.
The reason is that 00 was set. 16 is a support roller. Note that the transfer belt 100 may be provided with the three functions of 1) absorbing water in the web, 2) smoothing the web surface, and 2) adjusting the tension by using only 01.
Separated into book bell) 100A and belt 100B, belt 100A has the functions of ■ and ■ above, bell) 100B
It is also possible to provide the above-mentioned @ equipment.

Note that the heating roller of the present invention is not limited to one using the induction heating method as in the above embodiments, but may be one using any heating method.

Further, the pressing device of the present invention may be in the form of a fixed shoe instead of in the form of a roller.

[Effects of the Invention] As described above, according to the present invention, the amount of liquid removed per one heating roller is increased, and the state of liquid removal can be easily controlled, thereby improving the efficiency of liquid removal. , and the workability of liquid removal can be improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a moisture removal device according to an embodiment of the present invention, FIG. 2 is a schematic diagram showing an enlarged main part of the moisture removal device, and FIG. 3 is a schematic diagram showing a heating roller. Figure 4 is a schematic diagram showing an example in which the present invention is applied to a paper making line, Figure 5 is a schematic diagram showing another example in which the present invention is applied to a paper making line, and Figure 6 is a schematic diagram showing another example in which the present invention is applied to a paper making line.
The figure is a diagram showing the water removal effect of the present invention, FIG. 7 is a schematic diagram showing another embodiment of the present invention, and FIG. 8 is a schematic diagram showing a conventional paper making line. l...Web. 10...Moisture removal device, 11...Transfer belt, 11A...Supporting surface, 12...Heating roller. 13...pressure roller, 26...adjustment screw with knob position adjustment device), 28...
Web preheating device. Agent Patent Attorney Osamu Shiokawa Figure 1 Figure 4 Figure 5 Figure 6 Figure 6 2 Post WL, 1 (%) Figure 7 Figure 8 L

Claims (2)

[Claims] (1) A transfer belt that has a porous support surface and supports and transfers the web on the support surface, a heating roller that rotates in thermal contact with the web supported by the transfer belt, and a pressure contact device that is in pressure contact with the back surface of the carrying surface that supports the web of the belt and forms a nip area between the heating roller and the conveying belt and the web, and the heating roller Heat is delivered under high contact pressure to the web passing through the area, rapidly converting the liquid content in the web into vapor,
In a web liquid removal device configured such that the vapor penetrates the web and carries away any free liquid remaining in the web to the side of the porous bearing surface of the transfer belt, each of the plurality of pressure welding devices A web liquid removal device characterized in that a nip position adjusting device is installed at each position along the outer periphery of a heating roller and can adjust the distance between each nip region formed by each pressure welding device. . (2) The web liquid removal device according to claim 1, further comprising a web preheating device for preheating the entire web from both the front and back sides of the web, disposed upstream of the web line with respect to the nip region formed by the heating roller and the pressure contact device. .