METHOD FOR PRODUCTION OF HIGH YIELD SEMI-FINISHED PRODUCT FROM ASPEN Russian patent published in 2010 - IPC D21B1/02 D21B1/16 

FIELD: wood working industry.

SUBSTANCE: method includes steaming, impregnation with chemical reagents, two stages of chemical-thermal-hydrolytic treatment of wood chips, multiple grinding with extraction of steam condensates and recuperation of heat at the first stage of grinding. Soaking of ground mass in bath, washing of mass and formation of drain water flow. In zones of contact of products of chemical, chemical-thermal-hydrolytic, mechanical treatment of wood chips and/or fibrous dispersion with air of production premises, air mixture is extracted with contaminated water vapors released from products. Then drain water is saturated by this mixture. Afterwards drain water is exposed to floatation and additional biological cleaning.

EFFECT: reduced content of hazardous substances inside production premises below limit permissible concentration, reduced pollution of environment.

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