Step 1

A fixed volume of water is allowed to enter the mixing tube for use in diluting the pulp sample to 0.1% consistency.

Step 2

A fixed volume of pulp (200cc) is removed from either the stock line or tank.

Step 3

Vigorous stirring and mixing is accomplished with compressed air to ensure a uniform mixture at 0.1% consistency.

Step 4

There is a short pause to allow air to escape from the low consistency mixture

Step 5

By applying a constant air pressure to the mixing tube, the mixture is forced through the screen forming a uniform pulp mat. Excess water is drained externally.

Step 6

After a uniform pulp mat has been formed, the external drain valve closes and water begins filling the measuring tube.

Step 7

After a preset fixed time, the communicating valve between the two tubes closes and the water volume (height) collected in the measuring tube is measured by the bubbler tube. Back pressure to a differential pressure transmitter sends a low amperage signal to a recorder or computer. This signal correlates to the pulp sample freeness.

Step 8

After the freeness measurement has been completed, all valves open and the unit is thoroughly washed with high velocity water nozzles. Washing water is drained externally.

Note: This complete washing eliminates frequent wire cleaning, which is recommended for the Koei Freeness Tester only twice a year.