Method for producing dissolving pulp by oxygen continuous digesting method

Abstract

The invention relates to a production method for preparing a dissolving pulp by an oxygen-dissolving and continuous-cooking method, which applies the preparation of cotton linters in the production of viscose fibers in the textile industry, and the method comprises the following steps of: I. cotton linter pretreatments: including cotton linter loosening, cyclone separation and dust removal, feeding, two-roll grinding treatment, etc. to the cotton linters by a two-roll pulping machine; and II. oxygen dissolving and continuous cooking: a horizontal continuous cooking digester is adopted to realize the continuous, fast and low-pollution preparation of dissolving cotton pulp through the actions of high temperature, alkali, oxygen or hydrogen peroxide. The horizontal continuous cooking digester includes a pre-reaction bin, a two-roll gauge, a feeding screw, a T-shaped tube, a continuous-cooking tube and a cold discharge device. The method can effectively solve the problems of: cutting, tearing and cell primary wall breakage to the cotton linters by dry method after feed preparation, physical and chemical stripping to mass impurities in the cotton linters, fast accumulation reduction of the cotton linters in a continuous-cooking device and the purification of alpha cellulose under fast accumulation reduction, recycling of waste heat in the production link, and reduction of total amount of COD in a black liquor, and the method has advantages of even cooking and short cooking cycle.

Description

technical field [0001] The invention relates to a method for preparing cotton pulp, in particular to a production method for preparing dissolving pulp by using cotton linters for the production of viscose fibers in the textile industry by an oxygen decomposition continuous steaming method. Background technique [0002] Domestic cotton linter pulping technology is still at a relatively low production level. Except for some mint pulp mills that have started to use continuous cooking, others use traditional steaming balls for intermittent cooking. The pulping yield is not high, and the production The scale is small, the product quality is greatly affected by the processing quality of raw cotton linters, and the waste steam and black liquor produced by cooking have a great impact on the environment. With the adjustment of the national industrial policy, gap digesters such as steaming balls will be eliminated, coupled with the shortage of cotton linter resources, the overall qual...

AI Technical Summary

Problems solved by technology

This patent has changed the disadvantages of the traditional process of water, electricity, steam, alkali, time-consuming, and less pulp, but it cannot solve the problems of cutting, tearing and cell primary wall damage after cotton linter dry preparation, cotton short Physical and chemical removal of a large amount of impurities in cashmere, rapid depolymerization of cotton linters in continuous steaming device and purification of cellulose under rapid depolymerization, recycling of waste heat in production links, reduction of total COD in black liquor and other problems, and the cooking is uneven and the cooking cycle is long