Patent ID: 6833054
Filing Date: 2004-12-21
Classification: D21C,G01N,Y10S

Abstract:
A method for adjusting a chemical dosage of a pulp processing stage, the method comprisingdetermining, prior to adding the chemical dosage, a value of a selected variable representing a property of the pulp where the value is dependent on the chemical dosage to be added to the pulp, measuring the chemical dosage to be added, adding the chemical dosage to the pulp, determining the value of the variable associated with the pulp after adding the chemical dosage, determining, on the basis of the above-mentioned steps, the change in the value of the variable caused by the addition of the chemical dosage to the pulp, determining a model describing the change in the variable as a function of the chemical dosage, determining a performance index for the model, where the performance index represents the difference between an output of the model and actual data associated with the process, comparing the performance index of the model with performance indices associated with previously determined models, bringing into use the model that produced the best performance index in the comparison, and determining the necessary chemical dosage by means of the model put to use.