Upflow pressure screen is a new type of screening equipment for recycled pulp developed by our factory by absorbing imported prototype technology. The equipment is designed for upflow structure according to the characteristics of impurities in recycled pulp. It can be widely used in the rough screening of various waste pulps and the screening of pulps before paper machines. It has incomparable good performance and reliability. It is a renewal product of various domestic pressure sieves for the treatment of regenerated pulp.
As we all know, impurities in recycled pulp are divided into two parts: light impurities and heavy impurities. The traditional pressure screen consists of upper feed and low slag discharge. Light impurities pass through the entire sieve zone. When chemical pulp is treated, the specific gravity and mass of impurities in pulp are generally larger than that of single fiber. This structure helps to reduce the residence time of impurities in the equipment, but when the recycled pulp contains a large number of light impurities with a small proportion, it will greatly prolong the residence time of light impurities in the equipment, resulting in the decrease of screening efficiency and increase the wear and even damage of the sieve drum and the rotor.
This problem can be effectively solved by adopting the upflow structure design of bottom pulp feeding, bottom weight slag discharging and top light slag discharging. Light impurities and air in the pulp rise naturally to the top outlet and discharge, heavy impurities can settle to the bottom of the body and discharge as soon as they enter. On the one hand, it effectively shortens the residence time of impurities in the screen area, reduces the possibility of impurity circulation, and improves the screening efficiency. On the other hand, it prevents the damage caused by heavy impurities to the rotor and sieve drum, and prolongs the service life of the equipment.
1. Screen drum: The width of screen slot of fine screen drum is 0.12mm. Using corrugated bar screen drum, no burr groove is formed. It will not produce burr and crack at groove end like mechanical washing and grinding groove. The hard chromium plating process can be provided to improve wear resistance.
2. Rotary-wing rotor: the rotor adopts drum type external arc piece structure, and the dynamic balance is corrected. The sieve drum is cleaned by hydraulic pulse. This structure can prevent impurities from winding up the rotor, affecting the normal operation of the equipment.
3. Shell: It is composed of an upper cover and a cylinder body. The lower part of the cylinder body is provided with a tangential pulp feeding pipe, the upper part of the cylinder body is provided with a pulp outlet, and the upper cover is provided with a slag discharge port and a flushing water outlet.
4. Transmission device: including motor, belt pulley, V belt, belt tension device, spindle and bearing.
1. The lower part is used for pulp inlet, and the upper part is used for pulp outlet, so as to avoid pipeline crossing.
2. A stable base open design for easy maintenance and replacement of belts, pulleys and positioning bolts.
3. The power transmission and sealing device can be loaded and unloaded as a whole to reduce maintenance downtime.
4. Screen drum and rotor cleaning, adjustment, inspection and demolition are very convenient.
5. Various types of sieve drum can be used. Such as plain weave, corrugated sieve drum and so on.
6. According to the properties of pulp, various forms of rotor can be used.
7. The maximum operating pressure is designed to be 875Pa, which can meet various application conditions.
1. The fine sieve drum with 0.12mm slot width can effectively remove fine impurities in pulp and ink particles larger than 200 um after coarse sieve. Especially, the Stickies Removal Rate in pulp can reach more than 90%, which is currently the most recommended technology to replace all kinds of thermal dispersion equipment at home and abroad (the comparison of seam screening method and thermal dispersing method to solve sticky stickies are published in the third issue of "Paper and Paper Making" in 2000 by Professor Chen Jiaxiang, State Key Laboratory of Pulp and Paper Engineering, South China University of Technology: "Seam screening replaces dispersing machine in waste paper system" .
2. Heavy impurities are discharged into the heavy impurities tank at the bottom of the screen to prevent equipment damage caused by friction with the rotor and screen drum and reduce downtime.
3. Light impurities and air exits rapidly from the top outlet of tail pulp.
4. High screening efficiency. The short residence time of impurities in the sieve area significantly reduces the possibility of impurity cycling.
5. Low pulp pressure required.