Double-screen filter-pressing wash hollander

Abstract

The invention discloses a dual-network filter-pressing pulp washer, t includes the rack, the upper network which is installed on several net-rollers and movement is sealed and circulating and lower network which is installed on several net-rollers and movement is sealed and circulating, said several dewatering rollers are installed vertically in two rows, the lower of each dewatering roller is equipped with water-gathering device; the dewatering roller installed vertically can make the whole machine structure compact, the accommodation area small and the maintenance easier; the pulp washing water spraying device sprays washing water when washing pulp, and it can be used for the concentration of pulp when the pulp washing water spraying device does not work, the machine has two pueposes; the invention works through the using of gravity force and squeezing fully, cancels the vacuum suction and filter, greatly reduces power consumption and improves the reliability of the equipment.

Description

technical field [0001] The invention relates to a device for extruding and extracting black liquor before bleaching of various pulps, and for washing pulps before and after bleaching. Background technique [0002] Vacuum pulp washing machine commonly used at present (" pulp and paper making technology " page 332-337 published by Light Industry Press in September, 1980) utilizes vacuum suction to extract black liquor and wash paper pulp by rotating the drum However, the contact part of the drum and the stationary vacuum suction filtration system is subject to friction due to the rotation of the drum, which makes the contact part wear a lot, resulting in a decrease in vacuum degree, resulting in a decrease in the extraction rate of black liquor and a decrease in the washing effect. At the same time, Pulping is easy to occur in the unit of this equipment, which greatly affects the production capacity and increases power consumption. In severe cases, foam and slurry will overflo...

AI Technical Summary

Problems solved by technology

[0002] Vacuum pulp washing machine commonly used at present (" pulp and paper making technology " page 332-337 published by Light Industry Press in September, 1980) utilizes vacuum suction to extract black liquor and wash paper pulp by rotating the drum However, the contact part of the drum and the stationary vacuum suction filtration system is subject to friction due to the rotation of the drum, which makes the contact part wear a lot, resulting in a decrease in vacuum degree, resulting in a decrease in the extraction rate of black liquor and a decrease in the washing effect. At the same time, Pulping is easy to occur in the unit of this equipment, which greatly affects the production capacity and increases power consumption. In severe cases, foam and slurry will overflow the mesh tank, increasing the loss of fibers and black liquor, and polluting the environment.

[0003] In addition, there is also a horizontal belt vacuum pulp washer commonly used ("Paper and Paper" magazine, 1992, No. 1, page 38, sponsored by the China Paper Society), its filter surface is composed of an endless vacuum suction filter. The rubber filter belt moving along the horizontal plane on the plate is composed of an endless filter screen. The filter belt and the filter screen overlap, and are set on the drive roller and the rear roller. The drive roller drives the filter belt to run. During operation, the filter belt is sprayed with washing liquid. Washing and gravity, vacuum suction and filtration make the pulp layer on it concentrated and replaced and washed. The disadvantage is that the vacuum system is easy to leak or block, resulting in a decrease in vacuum degree, which directly affects the extraction rate of black liquor and the washing effect of pulp. Leakage of slurry and liquid on both sides of the filter belt occurs from time to time, which not only causes losses, but also pollutes the environment

[0004] Both the horizontal belt washing machine and the spiral mesh belt washing machine (see Chinese patent 90205627.1) use the suction effect generated by the vacuum pump or the negative pressure of the fan to repeatedly extract the pulp, and the countercurrent washing water needs to be connected in sequence by multiple circulating water pumps To the washing spray pipe of the previous stage, its power consumption is large, and the loss rate of fibers is relatively high

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