FI87587C - Device and method for drying cellulose - Google Patents

Description

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Apparatus and method for drying cellulose Anordning och förfarande vid torkning av Cellulosa 5

The invention relates to an apparatus and method for drying cellulose.

F1 patent 19 213 discloses an apparatus for drying cellulose. The apparatus comprises one or more drying chambers in which a rope conveyor is arranged for guiding the material path 10 along a kneeling path through the chamber. A patent solution is known from F1 patent 58,020, in which the pulp web is first treated by means of presses so that the dryness of the pulp web is 40-50%. The web is then introduced into a pulp diffuser where the pulp is disintegrated and the fiberized pulp is blown onto a moving wire. A porous fiber layer is thus formed on the wire. A combustion chamber is used to dry the fibers, and heated flue gases or other drying gases are passed through the fibrous layer to further dry the pulp web. A patent solution is known from F1 patent 35,704, in which air is blown onto the surface of the web and the web is passed in layers through a drying cabinet. A patent solution is known from F1 patent 33 855, in which the path is guided by air at a turning point.

20 None of the prior art solutions described above has satisfactorily solved the problems encountered in drying the web. Web drying in prior art solutions is not efficient enough. Thus, the web export becomes long and thus the equipment cost increases.

It is an object of the present invention to provide a cellulose drying apparatus which has been able to significantly enhance the drying of a cellulosic web. It is realized in the invention to form a device combination in which the cellulosic web is introduced in a loop-like and meandering manner inside the blowing cabinet, supported by the blowing air, and the web is pressed by means of press rolls connected to folding rollers.

In the solution according to the invention, the cellulosic web is thus adapted to pass through the press nips, and in the area between the press nips the drying is intensified by providing 2,37587 warm air or gas blowing through the web. Another function of the blowing air is to act as a web-supporting medium.

The device according to the invention for drying cellulose is mainly characterized in that the reversing cylinders have press rollers, whereby the reversing cylinders control the web in a loop and the press rolls press the cellulosic web to remove water from the cellulose, and the apparatus comprises by adjusting the actuators, the compression force and dewatering of the cellulosic pulp mill 10 can also be adjusted.

One or more of the press rolls may be internally or externally heated.

The method for drying cellulose according to the invention is mainly characterized in that the method uses press rolls in connection with the turning cylinders, whereby water is removed from the cellulose web in the press nips between the turning cylinders and the press rolls. and by evaporating the turning cylinders and the press rolls into an overlapping structure in the method, a compact space-saving structure is obtained from the drying cabinet.

The invention will now be described with reference to some preferred embodiments of the invention shown in the figures of the accompanying drawings, to which, however, the invention is not intended to be exclusively limited.

Figure 1 shows a method and an apparatus according to the invention in a partially schematic representation.

Figure 2 shows a press roll according to the invention in connection with a folding roll.

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The device 10 for drying cellulose comprises a drying cabinet 11 comprising an inlet opening 11a and an outlet opening 11b for the cellulose web M. The blowing cells 12a, 12b, 12c ... 12g located inside the body 11, into the inner space 13 of which warm pressurized blowing air is introduced, which is guided through the perforation 14 of the cell 12 towards the pulp web 5 of the cellulose 5. The cell 12 comprises a perforation 14 which a jet of warm air and / or gas is directed obliquely to the surface M of the cellulose web. Thus, said jet is directed to wipe the surface of the web, thereby further enhancing the spread of the jet and the drying effect of said jet in connection with the web M. Warm air is introduced into the cells 12a, 12b, 12c ... via the branch ducts Ti, T2, T3 ... T7 from the collecting duct C, where the blower device Pj is located, which provides the blowing through the heater E. Air is removed from inside the body 11 through the exhaust duct N. The exhaust is facilitated by the exhaust air fan P2. The figure shows with arrows L, the introduction of warm air into the web M. The web M is conveyed in a loop, kneeling from top to bottom, so that the web is guided by means of air Lj and by means of folding rollers 15 arranged at pivot points. As shown in the figure, a press roll 16a, 16b, 16c, 16d, -16e, 16f is arranged in connection with each folding roll 15a, 15b, 15c, 15d, 15e, 15f, whereby the web is pressed in press nips Nj, N2, N3, N4, N5 and N6, whereby the web remove the water. One or more of the press rolls may be internally or externally heated. Thus, in order to enhance the drying of the web, not only 20 warm air is directed to the surface of the web, but also the web is compressed at the turning point by a cold or heated press roll. The device fits in a small size because the web is meandering. Since the web passes in a meandering manner, the guide rollers and the press rollers can be placed inside the cover body 11 and thus considerably save a horizontal factory area. The gradual and stepwise introduction of the cellulosic web M through the press nips Nj, N2, ... N6 25 results in a uniform removal of water from the cellulose and thus a very uniform drying result is obtained.

In the event of web breaks, a rope guide (not shown) is arranged inside the body 11, by means of which it is possible to pass the web through the device at the beginning of the run or in the event of web breaks.

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Figure 2 shows the structure of the press nip in more detail. The press roll 16a is adapted to press against the folding roll 15a with the force provided by the actuator 17a, preferably the cylinder device. The water leaving the cellulose M is led to a collecting vessel 18 and further out from inside the body 11 (arrow L2).

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Claims (7)

A method of drying a cellulose web, in which method the cellulose web (M) is introduced in the form of a strip to a drying cabinet via an entrance opening (11a) in the body (11) and in which method the web is guided within the body (11) in the form of a loop that curves, wherein the path of the web is effected by means of interrupted cylinders (15a, 15b, 15c ...) and in the process hot air and / or hot gases are blown in connection with the cellulose web (M), with the aid of the hot blown air and / or the gases, the drying of the cellulose web (M) is promoted and the cellulose web (M) is supported in the form of a strip which curves inside the body (11), characterized in that in the process press rolls are used. (16a, 16b, 16c ...) in connection with the breaking cylinders (15a, 15b, 15c ...), removing water from the cellulose web (M) in the press nip (N1, N2, N3 ... N6) between the breaking cylinders ( 15a, 15b, 15c ...) and the press rolls (16a, 16b, 16c ...), turns The drying of the web (M) takes place both in the form of a dewatering in the press nip (Nj, N2 ... N6) and in the form of a water evaporation which takes place between the press nip and which is effected by the hot blown air and / or the gases and wherein in the process, a compact design of the dryer cabinet is obtained which saves space by arranging the break cylinder and the press rolls on each other. ... 20 2. A method according to claim 1, characterized in that in the method the press rolls (16a, 16b ...) are pressed against the break cylinders (15a, 15b ...) with a functional device (17), advantageously with a cylinder and the method collects the water removed from the cellulose (M) in the press nip (N 1, N 2 ... N 6) in a vessel (18) from where it is removed. Method according to claim 1 or 2, characterized in that the method uses at least one such press roll (16a, 16b ...) which has been heated. 30 8 87587 An apparatus for drying cellulose, which comprises a sleeve body (11) and an entrance opening (11a) and an exit opening (lib) therein for the cellulose web, and which comprises compressed air cells (12a, 12b ...) within the case ( 11), by means of which pressurized hot air is directed against the cellulose web to support and dry it, and which device comprises interrupted cylinders (15a, 15b, 15c ...) inside the case (11), characterized in that there are pressing rollers (16a, 16b, 16c ...) in connection with the breaking cylinders (15a, 15b, 15c), with the aid of the breaking cylinders controlling the web course in the form of a loop inside the case (11) and with the aid of the pressing rollers (16a, 16b) , 16c) the cellulose web (M) is pressed to remove the water from the cellulose and the plant comprises functional means (17a, 17b, 17c ...) by means of which the press rollers (16a, 16b, 16c) are pressed against the break cylinders (15a, 15b) , 15c), whereby by re gating of the functional devices (17a, 17b) can also regulate the compressive force and dewatering of the cellulose pulp web. 5. Device according to claim 4, characterized in that the plant comprises a water collection container (18a, 18b ...) below the nip (1 1, ... N6) between the break cylinders (15a, 15b, 15c) and the press rolls (16a, 16b). , 16c). Apparatus according to any of the above claims 4-6 for drying cellulose, characterized in that the press roll (16a, 16b, 16c) is heated.