Title:
セルロース材スラリー処理装置
Document Type and Number:
Japanese Patent JP4977086
Kind Code:
B2
Abstract:
Chemical pulp is produced from a slurry of comminuted cellulosic fibrous material using a beneficial additive such as AQ, or polysulfide. In the first treatment zone the effective alkali concentration and temperature conditions are such so that substantially no alkali degradation of the cellulose occurs, but so that the material is effectively impregnated with the additive. Then the material is treated with an alkaline cooking liquor, at cooking temperature, to produce a chemical cellulose pulp with higher yield or strength than if the low temperature, low alkali, additive pretreatment was not practiced. Typical alkali and temperature conditions in the first zone are less than 10 g/l expressed as NaOH, and between about 80-130° C., e.g. about 80-110° C. The first zone is preferably a feed system (which may include a separate impregnation vessel) for a continuous digester, while cooking is in a continuous digester.
Inventors:
See Bertil Stromberg
Joseph Earl Phillips
Joseph Earl Phillips
Application Number:
JP2008116793A
Publication Date:
July 18, 2012
Filing Date:
April 28, 2008
Export Citation:
Assignee:
Andritz Incorporated
International Classes:
D21C1/06; D21C7/00; D21C1/04; D21C3/00; D21C3/02; D21C3/06; D21C3/12; D21C3/22; D21C3/24; D21C3/26; D21C7/06; D21C7/14; D21C
Domestic Patent References:
| JP8296184A |
Foreign References:
| WO1998015687A1 | ||||
| WO1999045191A1 | ||||
| US5753075 |
Attorney, Agent or Firm:
Shizuo Nakamura