Andritz Inc.

Johann Aichinger

Marc J Sabourin

Eric Chao Xu

Jan Hill

Johann Grossalber

A thermomechanical pulping method including: refining pulp with a high consistency refining stage, and a medium consistency refining stage processing the refined pulp discharge from the high consistency refining stage. Chemical pretreatments for improving pulp quality development during medium consistency refining can be optionally added at the pressurized chip press, fiberizer pre-refining step, primary high consistency refining step, and/or the standpipe feeding the medium consistency refiner.

Medium consistency refining method of pulp and system

A mechanical pulping method including: defibrating a comminuted cellulosic material; mechanically refining the defibrated cellulosic material in a primary refining step; introducing to the cellulosic material at least one of a chemical agent and a biological during the defibration step or the mechanical refining step, and producing pulp from the refined and defibrated cellulosic material.

Method and system to enhance fiber development by addition of treatment agent during mechanical pulping

A non-compression vessel, such as a digester, is employed for the chemical preconditioning of the chips followed by a fiberizing device to break the preconditioned chips down to fiber bundles, which are then washed before a high consistency chemical treatment. The digester may be one such as used in conventional chemical pulping of wood with or without screens for the extraction of chemical. If extracted this chemical could be recirculated to the digester with treatment in the circulation loop such as heating or the addition of dilution or other chemicals. This digester may be hydraulic or vapor phase (that is contain a vapor space within the digester), and operate in either a continuous or batch fashion. This digester allows for the discharge of material without the use of a screw mechanism. The digester treated material is then defiberized to convert the chips into course fiber bundles, which then is washed and dewatered. The washed and dewatered pulp is then treated with alkali peroxide chemicals to develop brightness and other pulp properties.

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Pregarten, Austria

Johann Aichinger