Method and apparatus for feed-forward control of wood pulp refiners

Claim 1

A method as described by claim 1 wherein the value of total refining energy actually absorbed by said stock is derived from a known functional relationship that a static drainage rate value bears to total absorbed refining energy for a stock sample that is representative of the subject stock.

Claim 3

A method of controlling the magnitude of energy applied to a flow stream of aqueous slurry pulp stock by pulp refining engine means, said method comprising the steps of: A. obtaining a functional relationship between static drainage rate and total absorbed refining energy that is relevant to said stock; B. measuring the static drainage rate of said stock at a point in said flow stream before said engine means; C. deriving a first quantitative value from said measured drainage rate and said functional relationship that is representative of the total average specific energy that has been absorbed by said stock; D. selecting a second quantitative value that is representative of a desired total average specific energy to be absorbed by said stock; E. deriving a third quantitative value from the mathematical combination of said first and second values that is representative of a change in the magnitude of average specific energy delivered to said stock by said engine means necessary for said first value to substantially equal said second value; and F. controlling said engine means in response to said third value.

Claim 6

A method of controlling at least one pulp refining engine means comprising the steps of: A. obtaining from measured parameters a first quantitative value representative of the average specific energy applied to a pulp stock flow stream by said engine means; B. obtaining from measured parameters a second quantitative value representative of the average static drainage rate of said flow stream stock prior to working by said engine means; C. selecting a third quantitative value representative of a desired total average specific energy to be absorbed by said stock; D. obtaining a functional relationship between static drainage rate and total absorbed refining energy that is relevant to said stock; E. deriving a fourth quantitative value from said second value and said functional relationship that is representative of the total average specific energy that has been absorbed by said stock; F. deriving a fifth quantitative value from the mathematical combination of said first, third and fourth values that is representative of a change in said first value for the total average specific energy absorbed by said stock, as discharged by said refining engine means, to substantially equal said third value; and, G. controlling said refining engine means in response to said fifth value.

Claim 10

A system for controlling the magnitude of energy applied to an aqueous pulp slurry flow stream by refiner engine means, said system comprising: A. means for quantitatively measuring the static drainage rate of said slurry at a station in said flow stream prior to said refiner engine means; B. means for relating said drainage rate measurement to a first quantitative value of the total average specific energy absorbed by said slurry at the drainage rate measuring station; C. means for comparing said first value to a second quantitative value representative of a desired total average specific energy to be absorbed by said slurry; and, D. means for controlling the magnitude of energy applied to said slurry by refiner engine means responsive to a third quantitative value representative of a differential including said first and second values.

Claim 13

A system for controlling the magnitude of energy applied to an aqueous pulp slurry flow stream by refiner engine means, said system comprising: A. means for quantitatively measuring the static drainage rate of said slurry at a point in said flow stream prior to said refiner engine means; B. means for comparing said measured quantity to a second quantity representative of the static drainage rate desired for said slurry; C. means for functionally relating the comparative differential including said measured quantity and said second quantity to a magnitude and direction of change in average specific energy applied to said slurry by refiner engine means; and, D. means for controlling said refiner engine means responsive to the change determined by said functionally relating means.