Method and apparatus for measuring the throughflow quantity of a liquid substance per unit of time in a papermaking machine

Claim 1

A method for measuring the throughflow quantity of a liquid substance in the form of a fibrous suspension per unit of time in papermaking machine, comprising the steps of: providing a throttle element in the form of a performed plate having a number of essentially parallel channels through which flows the liquid substance therethrough with only a fine turbulence; infeeding the liquid substance to said perforated plate for throughflow in a predetermined direction of flow through said essentially parallel channels; and measuring the pressure drop at the throttle element essentially directly upstream and downstream of the throttle element with respect to the direction of flow of the liquid substance and wherein during the measurement of the pressure drop there does not occur any pressure fluctuations which adversely affect the measurement.

Claim 2

A method for measuring the throughflow quantity of a liquid substance in the form of a fibrous suspension per unit of time in papermaking machine, comprising the steps of: providing a throttle element in the form of a performed plate having a number of essentially parallel channels through which flows the liquid substance therethrough with only a fine turbulence; infeeding the liquid substance to said perforated plate for throughflow in a predetermined direction of flow through said essentially parallel channels; and measuring the pressure drop at the throttle element essentially directly upstream and downstream of the throttle element with respect to the direction of flow of the liquid substance and wherein during the measurement of the pressure drop there does not occur any pressure fluctuations which adversely affect the measurement.

Claim 4

An apparatus for measuring the throughflow quantity of a liquid substance in the form of a fibrous suspension per unit of time at a papermaking machine, comprising: a throttle element arranged in a predetermined direction of flow of the liquid substance; means for infeeding the liquid substance for flow through the throttle element; a device for measuring the pressure drop across the throttle element; means for comparing the pressure measured forwardly of and behind said throttle element; and said throttle element comprising a perforated plate having a multiplicity of essentially parallel channels through which flows the liquid substance and structured so that the liquid substance flowing therethrough has imparted thereto an extremely fine, essentially uniform turbulence; and said pressure measuring device comprises two pressure sensors positioned to measure the pressure drop directly forwardly and directly rearwardly of said throttle element, so that during the measurement there does not occur any pressure fluctuations that adversely affect the measurement.

Claim 5

An apparatus for measuring the throughflow quantity of a liquid substance in the form of a fibrous suspension per unit of time at a papermaking machine, comprising: a throttle element arranged in a predetermined direction of flow of the liquid substance; means for infeeding the liquid substance for flow through the throttle element; a device for measuring the pressure drop across the throttle element; means for comparing the pressure measured forwardly of and behind said throttle element; and said throttle element comprising a perforated plate having a multiplicity of essentially parallel channels through which flows the liquid substance and structured so that the liquid substance flowing therethrough has imparted thereto an extremely fine, essentially uniform turbulence; and said pressure measuring device comprises two pressure sensors positioned to measure the pressure drop directly forwardly and directly rearwardly of said throttle element, so that during the measurement there does not occur any pressure fluctuations that adversely affect the measurement.