硫酸盐法制浆中的节子处理

Knot Processing of the Sulfate Pulping

硫酸盐法本色木浆的未蒸解份(节子),通常采用回煮方式处理。本文介绍一种用双盘磨浆机处理节子的机械处理方法。其磨后浆进入纸袋纸系统后,纸机抄造正常,成纸质量无明显变化,经济效益显著。

Uncooked part (called knot in the following) in the sulphate wood pulping is usually sent back to digester for recooking. In this article, the mechanical treatment method by using double disc refiners to refine knot is studied. The mill-run results suggest that; (1) When the amount of the knot is about 10% in the system, the paper machine ran normally after the knot is refined and sent to the paper machine for producing sack kraft paper and the quality of the final product is not appreciably affected. (2) The φ915mm double disc refiner is used in the system. The running of this refiner is stable and reliable. (3) There is no iron-extracting equipment in the production line and hard impurities may affect the running. (4) When beating degree from the outlet pulp of the refiner is about 11-12°SR, the refiner has a production capacity of 14-15t/d, the existing production load is about 10-12t/d. (5) The flowsheet arrangement for knot in the brown pulp has effect on black liquor extract to some extent. The pulp washing is done before its deknotting. Residual alkali in the knot is remained in the thickening of the pulp; therefore, the arrangement for screening and washing and its working efficiency is important to black liquor extract. (6) This process has obvious economic benefit.