Use of filter cloth in filters
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Hello, experts. We use filter cloths in powder gasification systems for treating gray water. After a few days of use, these cloths start to turn red; after another ten or so days, the filter cake can no longer be dried. What could be the cause of this, and how can it be resolved? The iron ion content in gray water is 0.8 mg/l
The pH of gray water is around 8.5, the alkalinity is 5 mol/l, and the hardness is 6 mol/l
This is caused by a high pH value. Is it possible to adjust the pH value to neutral, or even slightly acidic?
The pH value has dropped slightly now; for me, a normal pH level of over 9.0 is fine, but now that it has dropped, it becomes a problem
It might be related to the amount of flocculant added
Consider the filter cloth washing water and check the washing effect. At the same time, if it is a vacuum filter, check the vacuum belt.
If the quality of the filter cloth is not taken into account, there may be the following reasons: 1. The amount of flocculant used might be too high; this can be determined by checking the water quality in the sedimentation tank and the bubbling on the water surface； 2. The filter may have been operated under overload for a prolonged period of time prior to this ； But whatever the reason, the filter cloth is in this condition now – its dialysis pores are basically blocked, and flushing the filter machine itself cannot resolve the issue; the filter cloth needs to be replaced
Is the reddening of the filter cloth related to the addition of flocculants, or is it due to iron ions in the coal?
This is likely due to the combined effect of total alkalinity and total hardness, causing certain substances in the black water to crystallize on the surface of the filter fabric and block its pores; in my opinion, ordinary regeneration methods seem unable to restore the breathability of the filter fabric.