EP 0778370 A1 19970611 - Process for the addition of a reducing bleaching agent to a high consistency paper fibrous material
Title (en)
Process for the addition of a reducing bleaching agent to a high consistency paper fibrous material
Title (de)
Verfahren zur Zugabe von reduzierendem Bleichmittel zu einem hochkonsistenten Papierfaserstoff
Title (fr)
Procédé pour l'addition d'un agent de blanchiment réducteur à une pâte à papier
Publication
Application
Priority
DE 19545852 A 19951208
Abstract (en)
A process to add reducing bleach substance (B) to highly consolidated paper pulp (S1, S2, S3) uses a dispersion machine with a processing region (3) for both pulp compression and mixing the bleaching substance with the pulp where the material is added at several points in the processing region. Preferably the temperature of the highly consolidated pulp is at or above 80 degrees C, the specific work applied to the pulp in the machine is at least 30 KWh per tonne and the pulp is compressed in the processing region to such a degree that free air content is less than 1% by weight of the moist pulp. Pulp compression is not continuous, the processing region being divided into an initial adjustable high compression zone and a following zone where the compression is less or zero and into which the bleaching substance is introduced. At the end of the high compression zone are variable open cross-sections through which the highly consolidated pulp passes and in the connecting zone the temperature is at or over 100 degrees C, the pressure at or over 1 bar. Flow at the end of the processing region is altered by an adjustable constriction.
Abstract (de)
Das erfindungsgemäße Verfahren dient der Zumischung von reduzierenden Bleichchemikalien (B) bei Verwendung einer Dispergiermaschine. Erfindungsgemäß werden die Chemikalien nicht vor der Dispergiermaschine oder beim Eintritt des Papierfaserstoffs (S1, S2, S3) in die Dispergiermaschine zugeführt, sondern über Bleichmittelzugabevorrichtungen (4, 4'), die innerhalb der Dispergiermaschine münden, und zwar dort, wo eine wesentliche Kompression des Faserstoffs bereits erfolgt ist. Dadurch wird der chemische Angriff des Luft-Sauerstoffs auf die Bleichchemikalien weitestgehend verhindert. <IMAGE>
IPC 1-7
IPC 8 full level
D21C 9/10 (2006.01); B01F 23/57 (2022.01)
CPC (source: EP US)
B01F 23/56 (2022.01 - EP); B01F 27/271 (2022.01 - EP); B01F 27/62 (2022.01 - EP); B01F 35/71775 (2022.01 - EP US); B01F 35/71805 (2022.01 - EP US); D21C 9/10 (2013.01 - EP); D21C 9/1084 (2013.01 - EP); B01F 23/57 (2022.01 - EP); B01F 27/2711 (2022.01 - EP); B01F 27/60 (2022.01 - EP); B01F 35/71 (2022.01 - EP); B01F 2025/9121 (2022.01 - EP)
Citation (search report)
- [Y] US 2716926 A 19550906 - BRUCE ARMSTRONG
- [Y] WO 8705346 A1 19870911 - ESCHER WYSS GMBH [DE]
- [A] WO 9427713 A1 19941208 - ANDRITZ PATENTVERWALTUNG [AT], et al
Designated contracting state (EPC)
AT DE FR SE
DOCDB simple family (publication)
EP 0778370 A1 19970611; EP 0778370 B1 20020417; AT E216443 T1 20020515; DE 19545852 A1 19970612; DE 59609090 D1 20020523; NO 965179 D0 19961204; NO 965179 L 19970609
DOCDB simple family (application)
EP 96116115 A 19961009; AT 96116115 T 19961009; DE 19545852 A 19951208; DE 59609090 T 19961009; NO 965179 A 19961204