Stock liquor pressure pulsation absorbing apparatus and method

Abstract

A stock liquor pressure pulsation absorbing apparatus of an active type is able to absorb pressure pulsations in an ordinarily demanded frequency range of 0.01 to 100 Hz. A by-pass pipe (2) extracts a portion of a stock liquor from a master pipe (1) for supplying the stock liquor to a paper machine headbox. A control pump (7) returns a portion of the stock liquor so extracted into the by-pass pipe. A detector (3) detects a stock liquor pulsation pressure at a branch point, or on an upstream side thereof, of the by-pass pipe and master pipe for controlling the control pump. The pressure pulsation, including the low frequency range, of the stock liquor is thereby absorbed accurately and precisely, variations in the basis weight are made small and a stable supply of final products with a high quality can be attained.

Dependencies are inferred from the claim text.