Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Development of wood grinding 3. Further testing of grinding models
The study is the continuation of a sequence of works devoted to describing the mechanisms occurring during stone grinding of wood. This part was aimed at further testing of pressurised grinding of spruce wood, which was conducted under controlled laboratory conditions. Testing of the developed theoretical model for power ratio (P c /P t ) versus energy specific production (Ġ w /P t ) produced linears for data representing constant wood moisture content. However, the linears showed almost identical results for fresh woods, and also for drier wood, e.g. wood containing saturated fibres and air-dried wood, although one would expect some differences due to the widely varying constant moisture, from 65% to 15% moisture content. Simplification of the model resulted in (c w + X c m ) ∆T p-w ≈ P t / Ġ w , and it led to specific linears, when the members as such were correlated between themselves at several constant wood moisture contents. The results were briefly as follows. Increasing wood feed rate – 0.7, 1.0 and 1.3 mm/s – decreased the specific energy requirement, while increased stone surface speed – 20 and 30 m/s – increased it. The left-hand member or the “X-factor” as named in this context, correlated with the right-hand member or the specific energy requirement and resulted in declining linears. The lower the wood moisture content – 65, 58, 44, 28 and 15% – the smaller was the linear declination, and also the difference due to stone surface speed. The application of an energy balance could be useful in searching for a working wood grinding model. Such a model would enable critical examination of wood grinding conditions. Also, it would help understanding the mechanism of various factors, such as grinding parameters, wood properties and stone burr and sharpness. It seems that there are factors that are not known well enough for further development of grinding. Shower water flow and temperature affect the stone surface temperature as known, but their significance for the energy balance or grinding mechanism are ...
Development of wood grinding 3. Further testing of grinding models
The study is the continuation of a sequence of works devoted to describing the mechanisms occurring during stone grinding of wood. This part was aimed at further testing of pressurised grinding of spruce wood, which was conducted under controlled laboratory conditions. Testing of the developed theoretical model for power ratio (P c /P t ) versus energy specific production (Ġ w /P t ) produced linears for data representing constant wood moisture content. However, the linears showed almost identical results for fresh woods, and also for drier wood, e.g. wood containing saturated fibres and air-dried wood, although one would expect some differences due to the widely varying constant moisture, from 65% to 15% moisture content. Simplification of the model resulted in (c w + X c m ) ∆T p-w ≈ P t / Ġ w , and it led to specific linears, when the members as such were correlated between themselves at several constant wood moisture contents. The results were briefly as follows. Increasing wood feed rate – 0.7, 1.0 and 1.3 mm/s – decreased the specific energy requirement, while increased stone surface speed – 20 and 30 m/s – increased it. The left-hand member or the “X-factor” as named in this context, correlated with the right-hand member or the specific energy requirement and resulted in declining linears. The lower the wood moisture content – 65, 58, 44, 28 and 15% – the smaller was the linear declination, and also the difference due to stone surface speed. The application of an energy balance could be useful in searching for a working wood grinding model. Such a model would enable critical examination of wood grinding conditions. Also, it would help understanding the mechanism of various factors, such as grinding parameters, wood properties and stone burr and sharpness. It seems that there are factors that are not known well enough for further development of grinding. Shower water flow and temperature affect the stone surface temperature as known, but their significance for the energy balance or grinding mechanism are ...
Development of wood grinding 3. Further testing of grinding models
Lönnberg, Bruno (Autor:in)
01.07.2021
Lönnberg , B 2021 , ' Development of wood grinding 3. Further testing of grinding models ' , Cellulose Chemistry and Technology , vol. 55 , no. 7-8 , pp. 795-797 . https://doi.org/10.35812/CELLULOSECHEMTECHNOL.2021.55.66
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
DDC:
690
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