Patent · US Expired

Method and device for treatment of fibrous material

US6206309A · kind A · utility

8Cited by

5References

6Claims

0Family size

Assignee

Valmet Fibertech Aktiebolag · SE

Inventors

Ove Danielsson · Stockholm, SE
Ola M. Johansson · Brookfield, US
Peter Svedberg · Flen, SE

Key dates

Filing date	Aug 23, 1999
Grant date	Mar 27, 2001
Priority date	—
Expiry date	Aug 23, 2019

Classification

Technology area (CPC D)Textiles; Paper
CPC primaryD21D1/30
WIPO fieldChemical engineering
WIPO sectorChemistry

Abstract

Methods and apparatus are disclosed for refining lignocellulosic material between a pair of relatively rotary refining elements forming an annular outer refining zone and a central feed zone. The method includes feeding the lignocellulosic material to the central feed zone, accelerating the lignocellulosic material through the central feed zone towards the annular outer refining zone without lignocellulosic material build up in the central feed zone and substantially without working the lignocellulosic material in the central feed zone, the density of the lignocellulosic material in the central feed zone being a maximum of about 10 kg/m.sup.3, and mechanically working the lignocellulosic material in the annular outer refining zone, and in which the relatively rotary refining elements have a relative speed of greater than about 50 m/sec.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.