METHOD AND DEVICE FOR TREATING LIQUID FLOWS IN PULP MILL Russian patent published in 2017 - IPC D21C11/00 

FIELD: chemistry.

SUBSTANCE: method of treating liquid flows in pulp mill, wherein device comprises a wood preparation unit, an unbleached pulp production unit comprising boiling, washing, sorting and oxygen delignification stages, to produce cellulose pulp, a bleaching unit to bleach the obtained cellulose pulp, a chemical regeneration block, a pulp-drying machine, a soda recovery boiler which generates blow-down water of the bolier, an evaporating apparatus which generates condensates, a waste water treatment plant and water production plant, wherein the method comprises transportation from at least one of the following water sources: A) bleaching filtrates (alkali-oxygen-peroxide) from the bleaching unit (30), B) sealing water of Nash pump from the bleaching unit (30), C) condensated from evaporating apparatus (40), D) water from the second settler of the waste water treatment plant (50), E) cooling water of injector condenser from the chemical regeneration block (60), F) sealing water of vacuum pump from the chemical regeneration block (60), and G) blow-down water of the soda recovery bolier (70) to at least one of the following usage centers: H) washing of logs at the wood preparation unit (10), I) chopping at the wood preparation unit (10), J) chip sorting at the wood preparation unit (10), K) conveyor for chip at the wood preparation unit (10), L) washing during oxygen delignification at the unbleached pulp production unit (20), M) thinning water at the unbleached pulp production unit (20), N) plates of drum device for displacement washing of the bleaching unit (30), P) thinning water at the bleaching unit (30), Q) water for sparging dehydrating plant of the pulp-drying machine (80), R) water for sparging gravitation table of the waste water treatment plant (50), S) tank for diluted liquor of the chemical regeneration block (60), T) tank for white liquor condensate of the chemical regeneration block (60), and U) mill water-supply system by connecting water sources to its usage centers according to the following pairs: - from the sourse A or D to the center H, - from the source A or D to the center I, - from the source A or D to the center J, - from the source A or D to the center K, - from the source A, B or D to the center L, - from the source A, B or D to the center M, - from the source B to the center N, O, P or Q, - from the source A, B, C, D, E or F to the center R, - from the source G to the center S or T, or - from the source E or F to the center U. The connection can be carried out according to one or more number of the pairs selected from the abovementioned pairs.

EFFECT: increased efficiency of treatment.

12 cl, 2 dwg, 3 tbl