METHOD OF ALKALI VAPORIZATION IN THE PRODUCTION OF CELLULOSE Russian patent published in 2018 - IPC D21C3/02 

FIELD: pulp industry.

SUBSTANCE: invention relates to the production of cellulose. Upon contact with metal surfaces, sodium polyalkylsiliconate creates a hydrophobic liquid film that prevents the formation of scale on heat exchange surfaces and deposits in the reaction equipment. At flow velocities of the moving liquid, such a concentration of sodium polyalkylsiliconate is selected, at which the weakened bond of scale or fibrous materials with a metal surface through a liquid film is destroyed and the process can be conducted in an unconstrained mode. Set task is achieved by the fact that the method for evaporating black liquor in the cellulose production, including weak liquor evaporating from process chips cooking from 10–25 % of absolutely dry substances (a.d.s.) to 60–80 % of a.d.s., at repeated evaporation in evaporative batteries with subsequent residual evaporation in concentrators and flash tanks, is carried out at a concentration of sodium polyalkylsiliconate at the point of its introduction into the solution in an amount of 1–50 Si-O / l of liquor.

EFFECT: achieved technical result of the proposed invention consists in introducing of well compatible with alkaline solutions sodium polyalkylsiliconate into black liquor.

1 cl, 3 ex