EP 0674731 A4 19970618 - METHOD AND APPARATUS FOR REGULATING WOOD PULP BLEACHING.
Title (en)
METHOD AND APPARATUS FOR REGULATING WOOD PULP BLEACHING.
Title (de)
VERFAHREN UND VORRICHTUNG ZUM REGULIEREN VOM ZELLSTOFFBLEICHEN.
Title (fr)
PROCEDE ET APPAREIL DE REGULATION DU BLANCHIMENT DE PATE DE BOIS.
Publication
Application
Priority
- US 9312135 W 19931213
- US 99318692 A 19921218
Abstract (en)
[origin: WO9415018A1] A method and apparatus for regulating reaction rate between a gaseous bleaching reagent and wood pulp in a bleaching system, of the type having a mechanically agitated pulp contactor (120), including the steps of co-currently or counter-currently introducing a recirculated contacting gas (R) for diluting freshly supplied reagent gas (F) and for thereby reducing the initial reaction rate between the reagent and pulp. Except for the initial reaction rate, overall bleaching performance is quite insensitive to wide variations in the amount of recirculating gas (R) introduced. This allows adjustment of flow rate to control gas velocity through the contactor (120) for purposes of overall bleaching efficiency. Degradation of pulp fibers due to overbleaching is virtually eliminated, and uniformity of bleaching is greatly enhanced without any sacrifice in production rate.
IPC 1-7
IPC 8 full level
D21C 9/10 (2006.01); D21C 9/153 (2006.01)
CPC (source: EP)
D21C 9/10 (2013.01); D21C 9/1026 (2013.01); D21C 9/153 (2013.01)
Citation (search report)
- [A] EP 0492040 A1 19920701 - KAMYR INC [US]
- [A] DE 4025616 A1 19910221 - ANDRITZ AG MASCHF [AT]
- See references of WO 9415018A1
Designated contracting state (EPC)
AT DE SE
DOCDB simple family (publication)
WO 9415018 A1 19940707; CA 2151813 A1 19940707; EP 0674731 A1 19951004; EP 0674731 A4 19970618; FI 953000 A0 19950616; FI 953000 A 19950616
DOCDB simple family (application)
US 9312135 W 19931213; CA 2151813 A 19931213; EP 94903630 A 19931213; FI 953000 A 19950616