In the horizontal tube continuous cooking system, the hydraulic washer is the key equipment in the pretreatment process. It is mainly used for the crushing of raw materials, fiber separation and impurity removal, and provides uniform and clean material input for subsequent continuous cooking. The following are its core functions and specific functions in the system:
1. Raw material crushing and fiber dredging
● Using the impact force of the high-speed rotating cutterhead and water flow, the grass raw materials (wheat straw, straw, reed, etc.) are broken into fine fiber bundles, destroying the rigid structure of the raw materials, which is convenient for the penetration of the liquid medicine during subsequent cooking.
● Example: In non-wood pulping (such as bamboo pulp, straw pulp), the whole bale of wheat straw is chopped into 3~ 5cm fiber segments to improve the cooking reaction efficiency.
2. Impurity separation and cleaning
● Through water vortex and filter device, the sediment, stone, metal and other impurities in the raw material are separated, and the scaling of the cooking tube or equipment wear is reduced.
● Example: When processing agricultural straw, more than 80% of the soil impurities attached to the surface of the raw material can be removed.
3. Fiber homogenization pretreatment
● Adjust the fiber length and fineness to avoid excessive or insufficient local reaction due to uneven raw materials during the cooking process.
● Example: The long fiber raw materials (such as hemp) are cut short to the specifications suitable for cooking to ensure the consistency of pulp quality.
4. Hydraulic conveying and mixing
● Using water flow as a carrier, the crushed fibers are preliminarily mixed with the cooking liquid (such as NaOH, Na ² S) to form a suspension and transported to the pin drum meter.
● Example: In KP pulping, the outlet of the hydraulic washer is directly connected to the injection point of the liquid medicine to achieve pre-impregnation of the fibers and chemical solutions.
