A method is disclosed for predicting the microbial status of a paper or board making process and/or quality of the dry board or paper obtained from the process for controlling microbial status of a paper or board making process or quality of the dry board or paper obtained from the process. Surface level and duration of time in at least one storage tower or pulper are monitored and correlated with respective predetermined values for the tower or pulper in order to predict the risk of microbial activity.

A method is disclosed for predicting the microbial status of a paper or board making process and/or quality of the dry board or paper obtained from the process for controlling microbial status of a paper or board making process or quality of the dry board or paper obtained from the process. Surface level and duration of time in at least one storage tower or pulper are monitored and correlated with respective predetermined values for the tower or pulper in order to predict the risk of microbial activity.

A dredging slurry system with a pulp tank is introduced, which is applied for a wet paper pulp molding apparatus. The system comprises the pulp tank, a dredging slurry mold seat, an activating unit, a slurry-physical-feature detection unit and at least one inflow unit and a control unit. The slurry-physical-feature detection unit is used to detect at least one physical feature from a slurry within the pulp tank, during a plurality of different stages, thereby relatively outputting a physical feature data. The control unit is used to control the at least one inflow unit to a manner whether to pour a newly-added slurry into the pulp tank or not, depending upon the physical feature data.

A dredging slurry system with a pulp tank is introduced, which is applied for a wet paper pulp molding apparatus. The system comprises the pulp tank, a dredging slurry mold seat, an activating unit, a slurry-physical-feature detection unit and at least one inflow unit and a control unit. The slurry-physical-feature detection unit is used to detect at least one physical feature from a slurry within the pulp tank, during a plurality of different stages, thereby relatively outputting a physical feature data. The control unit is used to control the at least one inflow unit to a manner whether to pour a newly-added slurry into the pulp tank or not, depending upon the physical feature data.

A method includes forming an aqueous fibre suspension including cellulosic fibres from one or more raw material flows, and applying at least one chemical and/or physical control measure to the aqueous fibre suspension or at least one of its raw material flows for control of microbial activity in the aqueous fibre suspension or the raw material flow before an inlet of an intermediate residence entity. In this manner a starting ORP value for the aqueous fibre suspension is obtained. The aqueous fibre suspension is in the intermediate residence entity at least a minimum delay time. A final ORP value is measured for the aqueous fibre suspension after an outlet of the said intermediate residence entity before the formation of the fibrous web. An ORP difference value between the starting ORP and final ORP values is calculated. Finally, the aqueous fibre suspension is formed into a fibrous web and dried.

A method includes forming an aqueous fibre suspension including cellulosic fibres from one or more raw material flows, and applying at least one chemical and/or physical control measure to the aqueous fibre suspension or at least one of its raw material flows for control of microbial activity in the aqueous fibre suspension or the raw material flow before an inlet of an intermediate residence entity. In this manner a starting ORP value for the aqueous fibre suspension is obtained. The aqueous fibre suspension is in the intermediate residence entity at least a minimum delay time. A final ORP value is measured for the aqueous fibre suspension after an outlet of the said intermediate residence entity before the formation of the fibrous web. An ORP difference value between the starting ORP and final ORP values is calculated. Finally, the aqueous fibre suspension is formed into a fibrous web and dried.

A screen feed arrangement for a pulp production process, comprising a discharge tank having an outlet, which is connected to an inlet of a discharge tank pump having an outlet, a dilution tank having an outlet, a screen feed pump having an inlet and an outlet, and a screening arrangement, wherein the outlet of the discharge tank and the outlet of the dilution tank are connected to the inlet of the screen feed pump, the outlet of which is connected to the screening arrangement, and that pulp which passes the outlet of the discharge tank has a mass concentration from about 8% to about 15%. A corresponding method for feeding pulp to a screen feed arrangement is also presented.

A screen feed arrangement for a pulp production process, comprising a discharge tank having an outlet, which is connected to an inlet of a discharge tank pump having an outlet, a dilution tank having an outlet, a screen feed pump having an inlet and an outlet, and a screening arrangement, wherein the outlet of the discharge tank and the outlet of the dilution tank are connected to the inlet of the screen feed pump, the outlet of which is connected to the screening arrangement, and that pulp which passes the outlet of the discharge tank has a mass concentration from about 8% to about 15%. A corresponding method for feeding pulp to a screen feed arrangement is also presented.

An accept tank arrangement for mixing of pulped fiber suspension including sidewalls (3,4) including opposite arched ends (2) and an elongated section (1) between the arched ends (2). The accept tank has mixers (10) each located within one of the arched ends (2). The mixers (10) have axles (11) on which are mounted propellers (12). The mixers (10) are aligned horizontally and each axle points to a respective point on the elongated section (1) of the sidewall (3) which away from an end of the elongate section by at least 25% of the length of the elongated section (1). The propellers (12) are symmetrically positioned with respect to a center-point of the accept tank. Within the center of the elongated section is an elongated centerpiece (6) having rounded ends. The accept tank has a substantially flat bottom at least at the elongated section (1) of the accept tank.

An accept tank arrangement for mixing of pulped fiber suspension including sidewalls (3,4) including opposite arched ends (2) and an elongated section (1) between the arched ends (2). The accept tank has mixers (10) each located within one of the arched ends (2). The mixers (10) have axles (11) on which are mounted propellers (12). The mixers (10) are aligned horizontally and each axle points to a respective point on the elongated section (1) of the sidewall (3) which away from an end of the elongate section by at least 25% of the length of the elongated section (1). The propellers (12) are symmetrically positioned with respect to a center-point of the accept tank. Within the center of the elongated section is an elongated centerpiece (6) having rounded ends. The accept tank has a substantially flat bottom at least at the elongated section (1) of the accept tank.