Method for recovery of compression wood and/or normal wood from oversize chips
AssigneeOy Separation Research Ab
InventorsChrister Eckerman, Bjarne Holmbom
Life of this patent
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Abstract
The invention relates to a method for recovery of branch knot wood and/or normal wood from oversize chips, and according to the invention the oversize chips are ground to splinter, which then is dried and mixed with water, and then the sedimented splinter containing high concentrations of extractive substances and having a high specific weight is recovered and extracted in order to recover valuable extractive substances, particularly lignans. The lighter splinter floating up to the water surface is recovered in order to recover normal wood material for the pulp production.
Claims8
A method for recovery of branch knot wood from oversize chips, characterised in that:
- the oversize chips are ground to splinter,
- the splinter is dried,
- the dry splinter is mixed with water, and
- the sedimented splinter containing high concentrations of extractive substances and having a high specific weight is recovered.
A method according to any previous claim, characterised in that the splinter is dried to a dry matter content of at least 85%, advantageously at least 87%.
A method according to any previous claim, characterised in that the sedimented splinter is fractioned and extracted in order to obtain extractive substances, particularly lignans, flavonoid, stilbens, tannins, isoflavonoids, and phenolic acids at a dry matter content of at least 85%, advantageously at least 87%.
A method for recovery of normal wood for the production of pulp from oversize chips, characterised in that
- the oversize chips is ground to splinter,
- the splinter is dried,
- the dry splinter is mixed with water, so that splinter rich in extractive substances and having a high specific weight is sedimented, and so that splinter rich in normal wood and having a lower specific weight will float up to the water surface,
- the splinter which is sedimented in the water is separated from the splinter floating up to the water surface and having a lower specific weight, and
- the splinter floating up to the water surface are recovered for the production of pulp.
Dependencies are inferred from the claim text.