Sökning: "Thermomechanical pulping"

Visar resultat 1 - 5 av 18 avhandlingar innehållade orden Thermomechanical pulping.

1. 1. 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

3. 2. 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

4. 3. Process intensification in mechanical pulping : Reduced process complexity and improved energy efficiency

   Författare :Christer Sandberg; Per Engstrand; Jan-Erik Berg; Göran Bengtsson; Mittuniversitetet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : This work shows that, for newsprint quality grades, the production processes for mechanical pulp can be simplified, and the specific electrical energy demand can be reduced with around 600 kWh/ton (30%). The purpose of the work is to demonstrate how the production cost for mechanical pulps can be decreased through increased energy efficiency and reduced number of unit operations. LÄS MER

5. 4. 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

7. 5. A Comprehensive Approach to Modeling and Control of Thermomechanical Pulping Processes

   Författare :Daniel Berg; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : The central issue of the thesis is modeling and control of the Thermomechanical Pulp (TMP) process in which large refiners are used to produce pulp for newsprint. The TMP process is one of the most complex and versatile, electricity consuming industrial processes today. LÄS MER