Andritz Technology and Asset Management Gmbh

Ola Larsson

Roland Kampris

Tinh Sjokvist

The present invention relates to a method of determining the moisture content of a web of cellulose pulp arriving at a pulp dryer. The method comprises measuring, at several instants during a predetermined time interval, the moisture content of said web using a moisture sensor arranged upstream of the pulp dryer; measuring state variables of drying medium of said pulp dryer; calculating, based on said moisture sensor measurements, a total value of moisture introduced into the pulp dryer by a portion of said web during said predetermined time interval; determining, based on said measured state variables, a predicted total value of moisture present inside the pulp dryer; comparing said calculated total value with said predicted total value to obtain a deviation therebetween; calibrating said moisture sensor using said deviation; and measuring the moisture content of a web of cellulose pulp using said calibrated moisture sensor.

Method of determining the moisture content of a web of cellulose pulp

A cellulose pulp drying box for drying a web of cellulose pulp having blow boxes that are operative for blowing gas towards the web of cellulose pulp for drying the pulp. At least 10% of the total number of blow boxes of the drying box are provided, in their respective face, with openings having a characteristic measure of 1.8 to 3. mm and constituting at least 20% of the total degree of perforation of the face of the respective blow box.

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Vaxjo, Sweden

Ola Larsson