Fiber energy efficiency Part II: Forces acting on the refiner bars
-
Anders Karlström
and
Karin Eriksson
Abstract
In this paper it is shown that the defibration and fibrillation work in thermo mechanical pulp refiners can differ significantly dependent on the process conditions. This has a direct impact on the distributed force in the refining zones obtained when the bars hit the fibers or fiber bundles. The distributed force, which is defined as a vector along the surface of the refining segments, is estimated using a model where the total work can be split into reversible and irreversible work. Besides traditional refiner variables such as motor load, dilution water added and inlet- and casing pressures, measurements of temperature profiles in the refining zone and plate gaps from a fullscale CD-refiner are available as inputs. Three data sets are analyzed and it is shown that the shape of the temperature profile and the force distribution vary significantly. This means that the fiber distribution in the refining zone varies as well which affects the final development of the pulp properties. The refining segment pattern and taper play an important role when estimating the force distribution and it is stated that the force distribution close to the contraction part of the flat zone as well as the outer part of the conical section are larger than in other positions. Therefore, specific energy which can be seen as the integral of the total energy distribution along the refining segments cannot be used when describing the variations in the distributed forces.
© 2018 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Introduction
- Crill: A novel technique to characterize nano-ligno-cellulose
- Characterisation of log loading process
- Effect of log loading on the performance of wood room
- A comparison of fibre deformations from mill like and laboratory kraft cooking of softwood
- Experimental study of some factors affecting pulp screen capacity
- Automated Drop-on-Fiber contact angle measurement using a microrobotic platform
- Analytical measurement of microstickies on fibers by model surfaces
- Increase of the filler content in papermaking by using a silica-coated PCC filler
- Effect of NaOH/urea solution on enhancing grease resistance and strength of paper
- Comparing the rheological properties of novel nanofibrillar cellulose-formulated pigment coating colours with those using traditional thickener
- Adjustable wetting of Liquid Flame Spray (LFS) TiO2-nanoparticle coated board: Batch-type versus roll-to-roll stimulation methods
- An evaluation method for print mottle using wavelet denoising and image grey level intensity gradient
- Factorial study of connections between process variables and kraft paper quality properties
- Directional emittance of dry and moist paper
- Tear and tensile strength development of PGW and CTMP pulps mixed with PLA or viscose fibres
- Paper strength improvement by inclusion of nano-lignocellulose to Chemi-thermomechanical pulp
- A method for preparing extensible paper on the laboratory scale
- Fiber energy efficiency Part I: Extended entropy model
- Fiber energy efficiency Part II: Forces acting on the refiner bars
- The influence of process waters on optical properties during storage of hydrogen-peroxide bleached Norway spruce mechanical pulp
- Some causes of formation of colour during storage of hydrogen-peroxide bleached Norway spruce mechanical pulp
Articles in the same Issue
- Introduction
- Crill: A novel technique to characterize nano-ligno-cellulose
- Characterisation of log loading process
- Effect of log loading on the performance of wood room
- A comparison of fibre deformations from mill like and laboratory kraft cooking of softwood
- Experimental study of some factors affecting pulp screen capacity
- Automated Drop-on-Fiber contact angle measurement using a microrobotic platform
- Analytical measurement of microstickies on fibers by model surfaces
- Increase of the filler content in papermaking by using a silica-coated PCC filler
- Effect of NaOH/urea solution on enhancing grease resistance and strength of paper
- Comparing the rheological properties of novel nanofibrillar cellulose-formulated pigment coating colours with those using traditional thickener
- Adjustable wetting of Liquid Flame Spray (LFS) TiO2-nanoparticle coated board: Batch-type versus roll-to-roll stimulation methods
- An evaluation method for print mottle using wavelet denoising and image grey level intensity gradient
- Factorial study of connections between process variables and kraft paper quality properties
- Directional emittance of dry and moist paper
- Tear and tensile strength development of PGW and CTMP pulps mixed with PLA or viscose fibres
- Paper strength improvement by inclusion of nano-lignocellulose to Chemi-thermomechanical pulp
- A method for preparing extensible paper on the laboratory scale
- Fiber energy efficiency Part I: Extended entropy model
- Fiber energy efficiency Part II: Forces acting on the refiner bars
- The influence of process waters on optical properties during storage of hydrogen-peroxide bleached Norway spruce mechanical pulp
- Some causes of formation of colour during storage of hydrogen-peroxide bleached Norway spruce mechanical pulp
