Operating Guide for Beating Freeness Tester
Beating Freeness Tester is a new type of instrument developed by our company according to national standards. The instrument is mainly used to measure the filtration rate of diluted pulp suspension, and is a conventional laboratory instrument with mature structure and clear technical requirements.
1. Rope pulley 2. Wrench 3. Funnel 4. Bottom hole 5. Sealing cone 6. Filter chamber 7. Side pipe
Operation Guide
1. Sample preparation
The samples are all taken from the dissociated slurry suspension. If the concentration of the slurry is not accurately known, it can be first diluted with distilled water or ion exchange water to a slurry concentration of approximately 0.22% and measured in accordance with GB/T 5399. Then dilute it to a concentration of 0.198~0.202% and adjust the temperature to 20 ± 1 ℃. During the sample preparation process, it is necessary to avoid the formation of bubbles in the suspension.
2. Adjustment of the lifting speed of the sealing cone:
Test the time t for the sealing cone to rise from the bottom of the water filter to the top (during which the buffer rubber sleeve does not deform), and measure the distance L (approximately 130mm) from the bottom of the water filter to the top edge. The average rising speed of the sealing cone can be obtained as V=L/t. V should be at: 100 ± 10mm/s, otherwise the length of the rope for hanging the heavy hammer should be adjusted appropriately (method: unscrew the hanging screw above the heavy hammer, adjust the position of the knot, and then tighten the screw again). The rope should be shortened and the speed should be faster! Make V reach this parameter. After testing, place the sealing cone at the top of the water filter cartridge.
3. Adjustment of remaining volume:
Block the bottom hole with your fingers and pour 100mL of distilled water at 20 ± 0.5 ℃ into the separation chamber. After the excess water completely flows out of the side flow tube, release the bottom hole and collect the water flowing out of the separation chamber. The volume of these water should be between 7.5-8.0 mL. If not, the position of the side tube should be adjusted to ensure the correct pressure head.
4. Sample testing:
Place the SR (Shaw Rieger) measuring cylinder under the side flow tube and place a water measuring cylinder under the bottom hole. Afterwards, rotate the rope pulley counterclockwise and place the conical cover at the bottom of the water filter. With a slight force, a slight "click" sound can be heard, and the rope pulley will be tightly fastened to seal the conical cover.
Take 1000 ± 5mL of the prepared slurry suspension into a measuring cylinder, stir evenly, and immediately pour it into the water filter cylinder. After five seconds, pull the small handle on the left side of the rope wheel box inward, and the sealing cone cover will automatically lift. The filtered water through the copper mesh will be discharged through the bottom hole and side flow tube through the separation chamber. When the side flow tube does not drip, read the degree value of the SR measuring cylinder under the side flow tube, which is the measurement result.
Each type of slurry should be measured twice, and the arithmetic mean value should be taken as the measurement result, but the relative error between the two measurement values should not exceed 4%.
5. Treatment after testing:
After the experiment is completed, clean the inside of the instrument with clean water (see maintenance and upkeep below), and finally place the conical cover on top.
