Wood-pulping equipment for paper- or card manufacture, employs compression refiner to complete fiber hydration and separation without damage

摘要

Soaked wood particles (S) with excess water, are processed to a fibrous pulp (S2) using a compression refiner (1). The wood particles are processed in a crushing zone between surfaces (4, 5) with rolling contact. The surfaces (4, 5) are external to crushing rollers (6) and internal (or external) to a rotating drum (3). Speeds of the contact surfaces differ by 10%. The consistency produced by the compression refiner is preferably 10%-20%. A specific energy consumption in the compression refiner of 400-600 kWh/t, produces pulp for card manufacture, with a specific volume of 2 cm3/g. Specific energy consumption of 800-1200 kWh/t, is used to manufacture graphic paper. The compression zone temperature is 30-50[deg]C. The temperature in the compression refiner is 70-130[deg]C. The soaked wood particles have a maximum preferred thickness of 1-3 mm. They are flat wood chips no more than 5 mm thick. Material used as wood particles result from driving a wood grinder at reduced power. The particles are soaked in water and chemicals (CH), swelling the cellulose and softening or embrittling the lignin. The pulp (S2) passes through a pressure sorter (10), which rejects (R) insufficiently-pulped components. The pulp (S2) is divided into fractions in a hydrocyclone (11), with similar oversize rejection. Reject material (R) is recycled to the compression refiner. Separated components may be further processed in a further compression refiner. They may be ground conventionally, to a consistency of 2% to 6%.