METHOD IN CONNECTION WITH THE PRETREATMENT OF COMMINUTED FIBROUS MATERIAL

摘要

A method in connection with the pretreatment of comminuted fibrous material intended for chemical cellulose pulp production, wherein said comminuted fibrous material is fed through a low pressure system comprising a gas phase part followed by a liquid phase part, said liquid phase part including a low pressure circulation where a circulating liquid is withdrawn from said fibrous material and is recirculated back to said fibrous material in an upstream position, said fibrous material is sluiced (4) into a high pressure system comprising a liquid phase transfer part operatively connected to a digester (19). Hot process liquid (11, 12) and/or said circulating liquid (10) is evaporatively cooled by being allowed to flash within said low pressure system.