EP 3464714 A4 20191225 - DOUBLE ALKALI CHARGING FOR CHIP IMPREGNATION

Title (en)

DOUBLE ALKALI CHARGING FOR CHIP IMPREGNATION

Title (de)

DOPPELT-ALKALI-LADEN ZUR CHIPIMPRÄGNIERUNG

Title (fr)

CHARGE D'ALCALI DOUBLE POUR IMPRÉGNATION DE COPEAU

Publication

EP 3464714 A4 20191225 (EN)

Application

EP 17803173 A 20170523

Priority

SE 1650742 A 20160527
SE 2017050555 W 20170523

Abstract (en)

[origin: WO2017204736A1] The invention relates to a method and an impregnation vessel where the bulk volume of impregnation liquor added is in form of hot black liquor having a residual alkali content. Hot black liquor is added in an upper central pipe supplying the hot black liquor as impregnation liquor and flashing off steam for driving off air from the comminute cellulose material. During this first steaming is the wood acidity released from the material and spent impregnation liquor with wood acidity content is withdrawn from an upper withdrawal screen to recovery, a lower withdrawal screen recirculates the remaining impregnation liquor to a second lower central pipe in order to equalize the alkali content well before the remaining retention time in the impregnation vessel. According to the invention is additional alkali added to the hot black liquor and the recirculated impregnation liquor respectively dependent on established alkali level in the liquor withdrawn from the upper withdrawal screen and the alkali level established below the lower withdrawal screen.

IPC 8 full level

D21C 1/06 (2006.01); D21C 3/24 (2006.01); D21C 7/06 (2006.01); D21C 7/12 (2006.01)

CPC (source: EP US)

D21C 1/06 (2013.01 - EP US); D21C 3/24 (2013.01 - EP US); D21C 7/06 (2013.01 - EP US); D21C 7/12 (2013.01 - EP US)

Citation (search report)

[A] WO 03106765 A1 20031224 - KVAERNER PULPING TECH [SE], et al
[A] WO 2010024763 A1 20100304 - METSO FIBER KARLSTAD AB [SE], et al
[A] WO 2012005643 A1 20120112 - METSO PAPER SWEDEN AB [SE], et al
[A] WO 2016072919 A1 20160512 - VALMET OY [SE]
See references of WO 2017204736A1

Designated contracting state (EPC)

AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DOCDB simple family (publication)

WO 2017204736 A1 20171130; BR 112018070795 A2 20190205; CN 109312537 A 20190205; EP 3464714 A1 20190410; EP 3464714 A4 20191225; US 2019194867 A1 20190627

DOCDB simple family (application)

SE 2017050555 W 20170523; BR 112018070795 A 20170523; CN 201780031762 A 20170523; EP 17803173 A 20170523; US 201716302851 A 20170523