Technology and equipment for increasing concentration of soda straw pulp black liquor

Abstract

The invention relates to a process and equipment for increasing the concentration of soda straw pulp black liquor, which is characterized in that the process is set between the concentration process and the combustion process of the traditional soda straw pulp alkali recovery process, steps: (1) heat treatment, the final pressure of black liquor is 1.0 ~1.2Mpa, temperature 175℃-180℃, to decompose high molecular weight polysaccharides in black liquor; (2) high-concentration evaporation, black liquor reaches a final concentration of 55% to 65%; (3) pressure heat storage; Booster pump, pre-heater, thermal mixer, final pressure booster pump, heat processor, flash evaporator, thick black liquor storage tank, A, B evaporation thickener, E, F circulation / delivery pump, final thick black hydraulic pressure The power storage tank constitutes. The advantages of the present invention are: energy saving and consumption reduction; straw pulp black liquor has good atomization dispersibility, is easy to burn, and does not block the air inlet; reduces device corrosion; only needs to add the process and technology provided by the present invention on the basis of the original straw pulp alkali recovery process. The equipment can run normally, reducing the investment cost of energy-saving transformation.

Description

technical field [0001] The invention relates to an alkaline straw pulp papermaking process, in particular to a process and equipment for increasing the concentration of the straw pulp black liquor through heat treatment, high-concentration evaporation and pressure heat storage of the alkaline straw pulp black liquor. Background technique [0002] In the papermaking industry, wood pulp or straw pulp is generally used for pulp. At present, straw pulp is mostly used in China, that is, grass such as wheat straw is used as raw material through alkaline pulping process; the main process is: firstly, wheat straw is mixed with caustic soda and steam Under the action of cooking and chemical reaction, organic matter such as lignin, polysaccharide carbohydrates and alkali lignin in wheat straw and caustic soda are dissolved in the cooking liquid to become black liquor, and the fibers in wheat straw are freed to become pulp; after separation and bleaching , the pulp is used to make pape...

AI Technical Summary

Problems solved by technology

In summary, how to increase the solid content of straw pulp black liquor, increase its concentration without increasing viscosity, so as to solve the existing problems of non-combustibility and low thermal efficiency of straw pulp black liquor, and make the treatment of straw pulp black liquor still possible Continuing to use traditional alkali recovery equipment has become a topic of concern in the industry

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