Roller type top-net forming device and its dewatering method

Abstract

The invention discloses a roller type top-net forming device and its dewatering method. The top-net forming device includes a top net, a main forming roller and several pre-forming rollers, in the conveying direction of wet paper sheets, the pre-forming rollers and the main forming roller are arranged in sequence, the pre-forming rollers are arranged below a bottom net, and the main forming roller is arranged above the top net; a suction box is arranged above the portion, corresponding to the pre-forming rollers, of the top net, the suction box is provided with a plurality of scrapers, each scraper corresponds to one pre-forming roller, and each scraper makes contact with the surface of the top net. The dewatering method includes the following steps that after the wet paper sheets enter a wet paper sheet conveying channel, the pre-forming rollers are used for multistage pre-dewatering, water generated by dewatering is brought out through the suction box, and the wet paper sheets are then fed into the main forming roller for dewatering along with the rotation of the top net and brought out through the bottom net after dewatering. According to the forming device and the method, extrusion force of wet paper sheets entering the interlayer region of the two nets and the bend degree of a conveying route are increased gradually, and thus the forming device can adapt to a wide quantitative range and a wide speed range.

Description

technical field [0001] The invention relates to the technical field of pulping and papermaking, in particular to a roller-type top wire former and a dehydration method thereof. Background technique [0002] The traditional fourdrinier paper machine relies on one side for dehydration, so that the retention of fillers and fine fibers on the web side is low, and the web side of the formed paper is rougher than the front side, resulting in a large difference between the two sides of the paper. At the same time, with the dehydration of the wire part, the concentration of the pulp layer continues to increase, and the fibers in the pulp layer begin to flocculate, and as the concentration increases, the degree of flocculation also begins to intensify, resulting in poor uniformity of the paper surface . [0003] At present, in some paper mills, in order to improve the paper formation of fourdrinier paper machines, in addition to selecting a good headbox, they often increase the trad...

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Problems solved by technology

However, these adjustment methods have not completely solved the above problems. When producing thick paper, there will still be forming problems due to the small curvature radius of the roller or the dewatering shoe and the excessive extrusion force of the two wires. At the same time, the above measures will also sacrifice Dewatering efficiency of top wire former

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