Sökning: "single disc refiner"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden single disc refiner.

  1. 1. Reduction of refining energy during mechanical pulping : using pressurised chip compression and sulphite pre-treatment

    Författare :Erik Nelsson; Geoffrey Daniel; Mittuniversitetet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; Chip pre-treatment; double disc refiner; energy efficiency; Impressafiner; low dosage; Norway spruce; refining intensity; single disc refiner; sulphite pre-treatment; thermomechanical pulp;

    Sammanfattning : The effects of pressurised compressive chip pre-treatment and low dosage sulphite pre-treatment were evaluated for production of thermomechanical pulp in mill scale trials using Norway spruce (Picea abies) at the Braviken paper mill (Holmen Paper AB, Sweden). The general aim of the study was to improve the energy efficiency during the production of mechanical pulps suitable for news and improved news grade papers. LÄS MER

  3. 2. Wood and fibre mechanics related to the thermomechanical pulping process

    Författare :Jan-Erik Berg; Per Engstrand; Per A. Gradin; Tomas Björkqvist; Mittuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustic emission; Chips; Compression tests; Defibration; Disc refiners; Energy consumption; Fibre structure; Force sensors; Fracture; Impact strength; Mathematical analysis; Moisture content; Picea abies; Refining; Stiffness degradation; Strains; Temperature; Thermomechanical pulping; Velocity; Chemical engineering; Kemiteknik;

    Sammanfattning : The main objective of this thesis was to improve the understanding of some aspects on wood and fibre mechanics related to conditions in the thermomechanical pulping process. Another objective was to measure the power distribution between the rotating plates in a refiner. LÄS MER

  4. 3. Measurement of shear force, temperature profiles and fibre development in mill-scale TMP refiners

    Författare :Hans-Olof Backlund; FSCN - Fibre Science and Communication Network; []
    Nyckelord :Shear force; Tangential force; Temperature profile; Thermomechanical pulping;

    Sammanfattning : Two different force sensors have been developed for tangential forcemeasurements in commercial TMP refiners, one is based on the use of piezoelectricsensors and the other on strain gauges. The measurements are used to learn moreabout the refining mechanism in both single-disc (SD) refiners and conical disc(CD) refiners. LÄS MER

  5. 4. Low consistency refining of mechanical pulp : process conditions and energy efficiency

    Författare :Stefan Andersson; Per Engstrand; Christer Sandberg; Mittuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mechanical pulping; low consistency refining; energy efficiency; rotor position; plate gap; fibre concentration;

    Sammanfattning : The thesis is focussed on low consistency (LC) refining of mechanical pulp. Theresearch included evaluations of energy efficiency, development of pulpproperties, the influence of fibre concentration on LC refining and effects of rotorposition in a two-zoned LC refiner. LÄS MER

  7. 5. Frictional studies and high strain rate testing of wood under refining conditions

    Författare :Birgitta Svensson; Hans Höglund; Per A. Gradin; Mittuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Friction; High strain rate testing; Wood; Mechanical pulping; Tribology; Refining; Energy consumption; Chemical engineering; Kemiteknik;

    Sammanfattning : When producing thermomechanical pulps (TMP), wood chips and fiber material are loaded mechanically in a disc-refiner to separate the fibers and to make them flexible. In the process, much of the energy supplied is transferred to the fiber material through cyclic compression, shear and friction processes. LÄS MER