Method and apparatus for simultaneous measuring the streaming potential of a fiber suspension and a filtrate thereof
AssigneeAB Innomatic
InventorRune Eriksson
Life of this patent
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Abstract
A method and apparatus for simultaneously measuring the streaming potential of a fiber suspension and a filtrate thereof. A container is provided having an inlet and an outlet for the flow of fiber suspension therethrough, and a filter screen divides the container into an upstream compartment and a downstream compartment. Each compartment has an electrode pair disposed therein, each electrode pair including a cylindrical outer electrode configured for flow of fiber suspension therethrough and an inner electrode. Each electrode pair is connected to a differential amplifier, with the differential amplifiers connected to a microprocessor.
Claims5
An apparatus for simultaneously measuring the streaming potential of a fiber suspension and a filtrate thereof, comprising a container having an inlet and an outlet for flow of fiber suspension therethrough, a filter screen dividing the container into an upstream compartment and a downstream compartment, a first electrode pair disposed in the upstream compartment comprising a first generally cylindrical outer electrode configured for flow of fiber suspension therethrough and a first inner electrode centrally disposed within the first outer electrode, a second electrode pair disposed in the downstream compartment comprising a second generally cylindrical outer electrode configured for flow of fiber suspension therethrough and a second inner electrode centrally disposed within the second outer electrode, a first differential amplifier connected to the first outer electrode and the first inner electrode for measuring potential difference therebetween, a second differential amplifier connected to the second outer electrode and the second inner electrode for measuring potential difference therebetween, a microprocessor connected to outputs from the first and second differential amplifiers, a valve disposed at the outlet for venting to the atmosphere and means for opening and closing the valve.
A method for simultaneously measuring the streaming potential of a fiber suspension and a filtrate thereof, comprising the steps of:
- a) causing the fiber suspension to flow through a filter screen to produce a filtrate downstream of the filter screen;
- b) opening and closing a valve to the atmosphere downstream of the filter screen to generate a pulsating pressure on the filter screen, and thereby to cause a pulsating voltage;
- c) measuring upstream of the filter screen a first differential voltage perpendicular to the direction of flow of the fiber suspension;
- d) measuring downstream of the filter screen and upstream of the valve a second differential voltage perpendicular to the direction of flow of the fiber suspension;
- and
- e) comparing the first and second differential voltages.
A method for simultaneously measuring the streaming potential of a fiber suspension and a filtrate thereof, comprising the steps of:
- a) causing the fiber suspension to flow through a container divided into upstream and downstream compartments by a filter screen;
- b) measuring a first differential voltage upstream of the filter screen perpendicular to the direction of flow of the fiber suspension with a first electrode pair comprising a first generally cylindrical outer electrode and a first inner electrode, the flow of the fiber suspension passing through the first outer electrode, said first outer electrode and said first inner electrode connected to a first differential amplifier;
- c) measuring a second differential voltage downstream of the filter screen perpendicular to the direction of flow of the fiber suspension with a second electrode pair comprising a second generally cylindrical outer electrode and a second inner electrode, the flow of the fiber suspension passing through the second outer electrode, said second outer electrode and said second inner electrode connected to a second differential amplifier;
- d) opening and closing a valve to the atmosphere downstream of the downstream compartment to generate a pulsating pressure on the filter screen, and thereby to cause a pulsating voltage;
- and
- e) comparing the first and second differential voltages with a microprocessor.
Dependencies are inferred from the claim text.