JPS5865092A - Method and apparatus for drying pulp sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to papermaking, and more particularly to O-grace drying of sheets such as paper, using at least four press rollers supported on substantially horizontal axes, the rollers being rotated relative to each other. A chamber is formed between the roller and the end seal by bringing it into contact with the roller, and air pressure is applied to the permeable surface of the roller to dry the sheet. The sheet is dehydrated and formed into a sheet, then the same sheet is pressed with rollers to dehydrate it again, and the sheet is further heated to achieve the final dryness.As is well known, dehydration by pressing is The cost is lower than dehydration by pressurization, because the equipment and energy required for pressing are small, and the equipment and θ energy required for heating are also small. The present invention relates to improvements in dehydration by pressurization. , about multiple pressing methods that reduce heating costs, improve fiber bonding, and increase paper strength.
pressure chamber means for extending the pressure above the pressure; and hydraulic means for compressing the impermeable belt means against the sheet and the deresurrection to form a small arc at the nip, ff.
The less method (MALTS-alp pr@551mg) is known. Pressure pad means are also known which press the sheet and felt against the small arcs of the second and f sections.

These prior art means have problems such as wear and tear of the equipment during dewatering and leakage, and the present invention seeks to eliminate these drawbacks.

The object of the invention is to overcome the problems of the prior art and to improve the pressing of sheets, and is therefore carried out by a method and apparatus having the following characteristics.

1. At least the same number of nips as the number of press rollers are provided for performing single-fold and double-felt processing, thereby improving the dehydration effect during sheet pressing and reducing the amount of heat and fuel consumption required for heating. -2,fless rollers] Squeeze the sheet through at least two nips and provide at least 44 2,fs to improve fiber bonding to increase the strength of the sheet.

3. By arranging at least four O press rollers on substantially horizontal axes and contacting each other in closed rows during rotation, the nip is further concentrated than in the prior art in paper machines.

4. By rotating the surfaces of at least 44 press rollers with respect to each other in a closed row, nip-to-nip alignment is maintained without measuring operation and independent of roller O diameter.

5. Gradually increase the Hennig pressure from the nip to the nip by elastically supporting some press rollers.

6. Attenuating nip vibrations that normally result from changes in the felt material by returning the vibrations of one roller in a closed row to the point of origin through the nip interference of the other rollers.

7. Applying pressurized air to the chamber bounded by the arc of the press roller itself and the end seal, the chamber is closed (a
) Pop from 471 means through the end seal! (b) via a ventilated hollow roll shaft to a pump; or (C) via an external shaft means to an engine;
The pressure exerted on the sheet by the generally arcuate shape of the at least one press roller is extended by forcing moisture out of the sheet with pressurized air throughout the drying process.

1. The pressure air load on the roller arc forming the wall of the chamber is reduced by the positive or negative pressure air load on the part f caused by a pressure higher or lower than the atmospheric pressure in the chamber around the roller. ,! Partially control pressure.

9. Suction and chive without opening! By continuously supporting the sheet from the nip section to the nip section, zero paper stress is removed during pressurization.

10. The centrifugal force acting on the sheet due to the arc of the press roller is offset by opposing air pressure or felt pressure or both along the arc.

In view of the above-mentioned characteristics, the present invention provides an apparatus for use in a paper making machine, which comprises at least four rollers arranged in combination on a horizontally mounted shaft,
The press rollers are brought into nip contact with each other in a rotationally open row to form a substantially sealed chamber between the press roller and the end wall.

At least one of the press rollers is a breathable curved-walled hollow body 9 for supporting at least one endless felt and for moving along at least some of the roller's curved support surfaces and for supporting the at least one endless felt. The endless felt is a breathable carrier for drying the paper sheet. At least one of the rollers is provided with elastic support means. By conduit means Air movement from the hollow roller to the chamber is effected. Air movement means are connected to the conduit means.

In operation of the apparatus of the invention, air is forced into the sheet on a well-ventilated roller surface surrounded by felt and sheet, extracting moisture from the sheet and transporting the moisture by conduit means.

The method according to the invention comprises at least four press rollers in nip contact with each other in series in a closed row to form a substantially sealed chamber between said press rollers and an end wall of said chamber; a wet valve seat supported by at least 41 endless felts in the nip contact between g and g;
the sheet and felt are inserted into the nip contact area between the third and forty-th la, and the sheet and felt are inserted into the nip contact area between the fourth and forty-th enters the nip contact area between the 20th roller and pressurizes the felt and/or armband sheet passing between the nip contact areas and pressurizes the sealed space formed by the rollers with air pressure. the sheet and the felt are dehydrated by passing air through the porous glue of at least one roller, and further discharging the sheet between the 40th roller and the 2nd p roller. It is.

By placing the rollers in closed rows, it is possible to determine which rollers should be permeable or non-porous, or whether the surface should be hard or soft, compared to other rollers in contact with them. It also helps in deciding whether to make it larger or smaller.

These distinct properties of nine rollers in a closed array are somewhat similar to the distinct properties of elements arranged in an organic compound oya. The nine closed rows of the press roller according to the present invention are combined with another closed row to form a chain, just as the rings of a cyclic compound in organic chemistry are combined to form a chain molecule. It's fun to form.

In selecting the roller surface, for example, softening the surface of at least one press roller in section 2 can prolong the life of the felt, while using a granite press roller in direct contact with the wet sheet. It is widely known that the sheet can be peeled off after nipping.

The appropriate selection of roller surfaces in this new combination of single and double felts will be obvious to those skilled in the ζO art.

Several parts are essential to the operation of the apparatus of the present invention and are well known and will not be explained or illustrated here, such as (1) a return mesh which operates like guide rollers, stretch rollers and felt cleaning means; In the present invention, the present invention includes a felt carrying roller, which is not counted as a press roller, (e) a frame, (d) an elastic support material for the press roller, and (e) a driving means. Also, nip contact at the roller means passing through the felt and likewise the sheet during operation.

The present invention will be explained in detail below based on the drawings.

In FIG. 1, a multi-nip suction press or drying device according to the invention is designated 10.

This device is used in a paper making machine that presses and dries sheets of nodal stock 11. The pressing device includes at least four press rollers, here stationary fixed roller 1.
2 and 12' and rollers 13 and 15. The roller 12d is elastically biased by a biasing means shown schematically at 914. In this embodiment, roller 12 is preferably a rounded granite roller 13 which directly contacts and peels the sheet.
and 15 can soften the surface, while roller 1
2' can make the surface hard. At least one of the rollers is here a hollow roller having an air permeable peripheral wall 16 wrapped with an endless belt, the air permeable carrier for drying the paper stock of the sheet 11, as shown in the figure the roller 15.

The four press rollers 12, 12', 13 and 15 are in close contact with each other in succession in a closed row, forming a nip at the contact between the rollers, which is indicated by the numeral 18. In this way, the four rollers expand to form four nips and apply pressure to the endless felt and the paper stock passing through the second and third portions.

Endless 7 L) 17 proceeds in the direction indicated by arrow 19, the felt being a breathable support for the paper sheet through which air transfers water to the outside of the delta. One of the rollers is connected to a drive source by means known in the art to provide rotational force to all four rollers.

The roller 12.12' is substantially sealed.

It is formed between the portion between 13 and 15 and the chamber end wall 21 (shown by an imaginary line in the figure). Breathable hollow roller IS and 1!
Suitable conduit means are provided which can be constructed in several ways to effect the movement of air to and from 2G. As shown in FIG.
2 to transmit air together with O moisture inside the cylinder. Similarly, the roller 13 may be a ventilated roller and may have connecting conduits 24 for air and moisture transfer. Rotation of the rollers 13 relative to the stationary conduit 24 is effected by known rotary coupling means 32. j!
A conduit 25 is connected to one end wall 210 to admit pressurized air. 1i 120 thus allows the air to pass through the endless felt 17 and through the permeable outer peripheral walls of the rollers 13 and 15, removing moisture from the endless felt 17 and through the hollow roller 213.
and 15, and conveys air and moisture by conduits 23 and 24. The roller 13 solidifies the open part and -
(5old who.)26. The provision of an external IC seal 26 for the roller 13 maintains a continuous seal from the atmospheric pressure at the end of the roller 13, and sealing with a shoe is easier to achieve than an internal seal 31.

In operation, the /4 luzo stock is led into a multi-nip press and the water is squeezed out with the first luzo. The water in the pulp stock is suctioned by hollow rollers 15 in a moving section within chamber 20. After that, Norepstock Company again became the 2nd and 3rd company.
2. It is squeezed in step D, and is further placed in the chamber 20, where a second movement is performed, during which suction is performed along the surface portion of the second f-response 13. In this manner, the paper stock exits the press in a drier state than is produced in conventional multi-nip presses.

FIG. 2 shows another example of conduit means. As shown, one hollow shaft has a ventilated surface and is elastically biased against the other three rollers. For example, the four-layer 28 may be a hard granite roller, and the four-layer rollers 229 and 30 may be f-mill rollers. The ingress of air occurs through the paper stock located between the felt and the large outer surface of the permeable roller 27, attracting moisture within the roller 27 and discharging it through the conduit 25 via the center @20. Ru.

The invention is not limited to the combination of air transfer means disclosed herein; other air transfer arrangements are possible.

In FIG. 3, an embodiment using a double felt press is shown. As shown in FIG.
is driven in an endless motion around the rollers 12, 12', 13 and 15, and is combined with another endless felt 17. Both endless felts are of breathable construction. The operation of the rounded double felt press for dewatering the rudest and lily is the same as that shown in FIG.

For example, a multi-nip suction press may include six rollers forming a chamber in the same roller and four ventilated rollers outside the same chamber and four ventilated rollers. Exhaust the air. Additionally, a seven-roller device is possible, with two sets of granite rollers aligned on three axes with nip contact between them, forming sealed chambers with outlets. , and exhaust the air through three breathable rollers! It is intended to supply

Another embodiment of the seven rollers according to the invention may be fixed in the center of one roller tube, with three four rollers in a plane approximately one
External nip contact is made with the center roller at 20 degree intervals, and the two through-hole rollers are placed between each other with two of the three flat rollers.
In addition, one sealing roller is in nip contact with two of the three flat rollers, and is spaced approximately 120 degrees outward from the centrally fixed roller.

[Brief explanation of drawings]

Figure 1 shows the features of the present invention! A schematic diagram showing an embodiment of the multi-unit suction press, the second diagram shows the multi-unit suction press according to the present invention.
FIG. 3 is a schematic diagram showing an embodiment of the multi-nip suction press using a double felt press. lO...Drying device, 11.../Material dest, ri, 12.1τ--constant roller, 13,1t...Press roller, 14...Bias means, 16...
Air permeable outer peripheral wall, 17... endless bell), 1B...
Nip portion, 20... Chamber, 21-- Chamber end wall, 22-- Air box, 23-- Conduit, 24-
... Stationary conduit, 25 ... Conduit, 26 ... Shade, 27 ... Air permeable roller, 28 ...
Roller, 29.30...f Roller, 31
...Inner seal, 32-...Rotating coupling means. Procedural Amendment Document Showa Year/Month 1/Relationship of the Case with the Indicated Cases Applicant 4, Agent Amendment Sai We will amend the following items in the specification of the application. Note 1: The scope of claims is amended as shown in the attached sheet. Claim 1: At least four stress rollers are connected in a closed row and in close contact with each other to form a sealed chamber between the stress roller and the end wall of the chamber. A moisture-containing valve seat supported by at least one endless felt is inserted into the contact portion between the 10th-layer and the 20-5, and the seat and the felt are connected to the first
The sheet and felt are inserted into the contact area between the third and fourth o-ra, and the sheet and felt are inserted into the contact area between the third and fourth o-ra. The felt and the valve seat are pressed into the contact portion between the fourth and twentieth holes, and the felt and the valve seat are pressurized in the contact portion between the fourth and twentieth holes. applying air pressure to the sealed space formed by the 40th-La porous rim, passing air through at least one O-La porous rim to dehydrate the moisture in the sheet and the felt; A method for drying a pulsed sheet using pressure, wherein the sheet is discharged between 20th and 5th. 2. At least four rollers are in continuous contact with each other in a closed row to form a substantially sealed chamber between the rollers and the end wall of the moeki chamber; at least one endless felt disposed to extend along at least some external support surface portions of the roller and through all of the contact areas; and at least one of the endless felt rollers supporting the endless felt. One is a hollow 0-arm whose outer wall is breathable, and the contact part is designed to apply pressure to the felt and paper sheet passing through the same part. an air-permeable carrier for drying the sheet, furthermore elastic support means for at least one roller, driving means for at least one roller, spinning hollow rollers;
- a conduit for moving air through the chamber and air displacement means connected to the conduit, the moving air passing through the sheet carried on the endless felt and removing moisture from the sheet; A drying device for use in a paper making machine, characterized in that the drying device is configured to extract water and transfer the extracted water through the conduit. 1. Indication of the case Relationship with the Showa Q year patent application No. I//7bo 7 case
7°゛λ7-4, Agent Address: 330 Marunouchi Shigesu Building, 2-6-2 Marunouchi, Chiyoda-ku, Tokyo Name (3667) Taniyama Terukiro & Contents of amendment: As attached.

Claims (1)

[Scope of Claims] 1. At least four breath rollers are closed in nine rows and are in continuous contact with each other to form a substantially sealed chamber! at least one endless felt formed on a res roller and an end wall of said chamber and disposed to extend along at least some external support surface portions of said roller O and through all of said leek f contact areas; At least one of the breath rollers supporting the endless felt is a hollow roller whose outer surface is breathable; The contact portion is adapted to apply pressure to the felt and the paper sheet passing through the rotating portion, and the endless felt is an air permeable carrier for drying the paper sheet, and further provides elastic support for at least one breath roller. means, at least one (drive means for a Dfless roller, a conduit for moving air through said hollow roller and said chamber;
and an air displacement means connected to the conduit, wherein the moving air passes through the sheet supported by the endless felt, extracts moisture from the sheet, and transports the extracted moisture through the conduit. A drying device used in a paper making machine, characterized in that it has the following characteristics: 2 At least 4! Connect the Resrollers in a closed row and go further! contact and seal to form a nine chamber between the breath roller and one end of the chamber, supported by at least one endless felt in the contact portion of the jll roller and the 20th roller. Charge the delta sheet containing moisture, enter the sheet and felt into the leek l contact area between the 3rd and 40th la of the GT crawler, and insert the sheet and felt between the 3rd and 40th la. the sheet and the felt into the fourth and second contact areas.
Enter into the contact area of the error between 0 and RA, and insert the front 2. pressurizing the felt and the /4rug sheet passing between the turns in the contact area of the roller, applying air pressure to the sealed space formed by the rollers, and applying air pressure to the porous glue of at least one roller; A method for drying a Δrug sheet by passing air to remove moisture in the sheet and felt, and then discharging the sheet between the 4th c1-ra and the 20th c1-2 pressure.