EP 1816259 A1 20070808 - Use of carbon dioxide for pH control of the wet end section of a paper machine
Title (en)
Use of carbon dioxide for pH control of the wet end section of a paper machine
Title (de)
Verwendung von Kohlendioxid zur Optimierung des pH-Werts im nassen Teil der Papiermachine
Title (fr)
Utilisation du dioxyde de carbone pour optimiser le pH dans la partie humide de la machine à papier
Publication
Application
Priority
EP 06300114 A 20060207
Abstract (en)
A method for controlling pH in the flow of cellulose pulp in a paper machine where carbon dioxide is introduced into at least one aqueous medium circulating in the wet end, in which the amount of CO2 introduced is a function of the pH of saturation of calcium carbonate (pHs). A method for controlling pH in the flow of cellulose pulp in a paper machine where carbon dioxide is introduced into at least one aqueous medium circulating in the wet end, in which the amount of CO2 introduced is a function of the pH of saturation of calcium carbonate (pHs), defined as pHs = -log[H3O+>], with [H30+>]2>s + (2 x K2 - (TAC X [Ca2+>] X K2)/Ks) X [H30+>s + Ke = 0; where TAC = [OH->] + 2.[CO32->] + [HCO3]>, K2 = [H30+>] x [CO32->]/[HCO3->, kS = [Ca2+>] {CO32->] and Ke {H30+>][OH->]. An independent claim is included for a device for use in this method, in which all or part of the carbon dioxide is introduced into the short white-water circuit and/or the long white-water circuit.
Abstract (fr)
La présente invention concerne l'utilisation de dioxyde de carbone pour contrôler les propriétés calco-carboniques des eaux lors de la formation d'une feuille de papier dans la machine à papier, elle se rapporte plus particulièrement à un procédé de contrôle du pH du flux de pâte cellulosique pour la fabrication d'un produit papetier entrant dans la machine à papier, procédé dans lequel on introduit du dioxyde de carbone dans au moins un véhicule aqueux circulant dans les circuits de la partie humide (wet end).
IPC 8 full level
D21H 17/67 (2006.01); D21C 9/00 (2006.01); D21H 17/64 (2006.01); D21H 17/70 (2006.01)
CPC (source: EP)
D21C 9/004 (2013.01); D21H 17/64 (2013.01); D21H 17/675 (2013.01); D21H 17/70 (2013.01)
Citation (search report)
- [DX] WO 9856988 A1 19981217 - AGA AB [SE], et al
- [X] WO 03050356 A1 20030619 - LINDE AG [DE], et al
- [Y] WO 02097189 A1 20021205 - LINDE AG [DE], et al
- [Y] CA 2377695 A1 20010118 - LINDE GAS AG [DE]
- [DY] US 6207062 B1 20010327 - DE RIGAUD JEAN-MATHIEU [FR]
- [DY] WO 9924661 A1 19990520 - AGA AB [SE], et al
Designated contracting state (EPC)
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR
Designated extension state (EPC)
AL BA HR MK YU
DOCDB simple family (publication)
DOCDB simple family (application)
EP 06300114 A 20060207