The obstructed settling machine achieves particle size separation in wet
classification of quartz sand by ascending water flow, and stable bottom flow
concentration is a prerequisite for ensuring classification accuracy. But many
customers have found that the bottom flow concentration fluctuates between high
and low. When it is high, the discharge valve quickly blocks, and when it is
low, it becomes as thin as water, which affects the subsequent pressure
filtration or dehydration processes. The problem usually lies in the
coordination of the rising water flow, feeding amount, and discharge valve.
The pressure of the rising water flow is unstable, and the concentration of
the bottom flow jumps accordingly. When the inlet pressure fluctuates, the
upward flow velocity fluctuates, and the settling state of fine particles
changes accordingly. When the pressure is too high, fine particles are washed
back into the overflow, and the bottom flow concentration is too low; When the
pressure is low, fine particles sink into the bottom flow and the concentration
is high. It is recommended to install a pressure gauge on the inlet pipeline to
maintain a stable water pressure in the range of 0.1-0.2 MPa. When the water
pressure fluctuates greatly, check the front-end water pump and valve, and
install a pressure stabilizing tank if necessary.
The feeding amount fluctuates, and the bottom flow concentration is also
unstable. When the front-end incoming material suddenly increases, the amount of
material in the tank increases, and the bottom flow discharge cannot keep up,
resulting in an increase in concentration; When the incoming materials decrease,
the bottom flow becomes thinner again. Add a buffer tank in front of the
settling machine to control the fluctuation of the feeding amount within ± 10%.
Check the feed concentration and flow rate once per shift, and promptly
investigate the front-end equipment if any fluctuations exceed the standard.
The opening of the discharge valve remains fixed and cannot adapt to changes
in working conditions. When the bottom flow concentration changes, the discharge
valve still maintains the same opening. If the concentration is high, it cannot
be discharged, and if the concentration is low, the discharge is too dilute. It
is recommended to adjust the valve opening in a timely manner based on the
bottom flow concentration detection results, or switch to automatic regulating
valve linked concentration meter control. If the valve is not tightly closed
after wear, it can also lead to uncontrolled bottom flow concentration. Check
the wear of the valve core and seat once a quarter, and replace them in a timely
manner if they are severely worn.
During daily inspections, samples are taken every 2 hours to test the bottom
flow concentration. If it is found to be consistently high or low, follow the
order of "check the water pressure first, then check the feeding amount, and
finally check the discharge valve" for troubleshooting. Encountering problems
during equipment operation, welcome to contact the technical team of Shandong
Heavy Industry for communication: Manager Zhang 13583776655 (same as
WeChat).