What paper workers should know and do

1. The purpose of refining? 
Answer: According to the quality requirements of paper or cardboard and the type and characteristics of the pulp used, physical methods are used to improve the shape and properties of fibers under controlled conditions, so that the manufactured paper or cardboard meets the expected quality requirements.
2. The main task of refining? 
Answer: (1) Use physical methods to mechanically treat the fiber suspension in water, so that the fibers are subjected to shearing force, changing the shape of the fibers, so that the pulp can obtain certain characteristics (such as mechanical strength, physical properties), so as to ensure that the paper is produced. The products achieve the expected quality requirements.
(2) Through refining, control the water filtration performance of the paper material on the wire to meet the needs of the production of the paper machine, so that the paper web can be well formed, and the evenness and strength of the paper sheet can be improved.
3. What changes have happened to the fiber during the refining process?
Answer: (1) Displacement and deformation of the cell wall
(2) Rupture of primary wall and outer layer of secondary wall
(3) Water absorption and swelling
(4) Fine fibrillation
(5) Transverse cutting
4. What are the factors that affect the refining?
Answer: (1) Refining specific pressure
(2) Refined concentration
(3) Refining temperature
(4) Throughput

5. What are the reasons why the slurry pump is not sizing?
Answer: (1) The slurry is mixed with debris, which will block the slurry pump.
(2) Air is mixed into the slurry pump or slurry.
(3) The slurry concentration at the bottom of the slurry tank is high, and the slurry feeding resistance is large.
(4) The diameter of the slurry feeding pipeline is small, the elbows are many, and the distance is long, resulting in a large slurry feeding resistance.
(5) There is sludge in the pipeline, which blocks the pipeline.
(6) The liquid level in the slurry tank is low, and the slurry entrains air into the slurry pump.
(7) After the newly installed slurry pump or slurry pump motor is overhauled, the motor wiring is wrong, and the pump cannot be reversed for sizing.
6. What are the factors that affect the purification efficiency of the desander?
Answer: (1) Pressure difference between inlet and outlet
(2) Slurry concentration
(3) Properties of the slurry
(4) Relative density and thickness of removed impurities
(5) Diameter of sand removal nozzle
(6) The smoothness of the inner wall of the desander