Method and assembly for processing cellulose pulp of wood processing industry

An assembly for processing cellulose pulp:

• a pressurized digester vessel having an inlet for wood chips and an outlet for pulp digested in the vessel;
• a washer receiving the pulp from the digester vessel;
• a bleaching device receiving washed pulp from the washer, and
• a pressurized separation apparatus receiving into a pressurized chamber filtrate from the washer, and discharging a liquid fraction to the digester vessel or the washer, wherein the pressurized chamber is at a pressure above atmospheric pressure at least while receiving the filtrate and discharging the liquid fraction.

A method of processing cellulose pulp of wood comprising:

• producing pulp by chemically digesting comminuted cellulosic fibrous material in a pressurized digesting vessel, wherein the pressure in the digesting vessel is above atmospheric pressure;
• washing the pulp and discharging wash filtrate, wherein the bleached pulp is washed at a pressure above atmospheric pressure;
• bleaching the pulp in a bleaching stage, wherein the pulp is bleached at a pressure above atmospheric pressure, and
• separating at least one of soap, gas and other light materials from the wash filtrate while the wash filtrate is under pressure greater than an atmospheric pressure and is in a pressurized separation device;
• wherein the washing step uses a pressure diffuser to wash the digested pulp and the filtrate received by the pressurized separation device is received from the pressure diffuser and wherein the filtrate remains under a pressure above atmospheric pressure while flowing from the washing step to the pressurized separation device.

An assembly for processing cellulose pulp:

• a pressurized digester vessel having an inlet for comminuted cellulosic fibrous material and an outlet for pressurized pulp chemically digested in the vessel;
• a pressurized washer receiving the pressurized pulp from the pressurized digester vessel and discharging pressurized filtrate,
• a pressurized bleaching device receiving the pressurized pulp from the pressurized washer, and
• a pressurized separation apparatus configured to receive the pressurized filtrate from the pressurized washer, separate a liquid fraction from the pressurized filtrate while the pressurized filtrate remains at a pressure above atmospheric pressure, and discharge the liquid fraction to the digester vessel or the washer.