Method of reducing the energy consumption at the refining of cellulose containing material
AssigneeStfi
InventorsPer O. Engstrand, Lars-Ake Hammar, Myat T. Htun, Rune L. Pettersson
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Abstract
Method of reducing the energy consumption at the refining/beating of cellulose-containing material by the addition of alkali to the material for neutralizing acid groups bonded to the fibre wall. According to the invention, the pH-value in the pulp suspension is measured at the refiner outlet, the alkali is added in an amount depending on the measured pH value for neutralization without excess in the beating zone or immediately before the material enters the same, in an amount of 0.05-9 kg/ton, preferably 0.5-5 kg/ton, suitably 1-4 kg/ton, calculated as NaOH.
Claims1
A method of reducing the energy consumption at the refining or beating of cellulose containing material to predetermined strength properties and with reduced shieves and resin content which comprises adding alkali to the material for neutralizing acid groups bounded to the fibre wall, said alkali being added to the material in the refining zone or immediately before the material enters the refining zone, and said alkali being added as sodium hydroxide in an amount of about 1-4 kg per ton for neutralization without excess.
Dependencies are inferred from the claim text.