Turbid water quality/exceeding standards
Causes : filter media failure or disordered layers, incomplete backwashing, excessively high influent turbidity, and short circuit caused by damaged filter cap.
Solution :
If the filter media wear rate exceeds 30% or the particle size distribution is disordered, replenish/replace the filter media in layers ;
Strictly control water inflow
Check the filter cap /
(＞0.1MPa) The pressure difference between the inlet and outlet is too high (>0.1MPa).
Causes : filter media caking, influent containing sticky substances, insufficient backwashing intensity, and excessive filter media layer height.
Solution :
A combination of air wiping and water backwashing is used to remove sticky impurities from the surface of the filter media;
Adjust the backwashing intensity according to the filter media type (but not exceeding the upper limit), and extend the backwashing time until the drainage is clear;
If the filter media is severely caked and cannot be restored, replace the upper layer of ineffective filter media .
Check the height of the filter media layer and reduce it to the design value to avoid excessive water flow resistance caused by excessively thick filter media.
The pressure difference is too low (<0.03MPa) and the effluent is turbid.
Causes : Severe loss of filter media, insufficient height of filter media layer, and damage to filter cap/screen.
Solution :
Stop the machine to check the height of the filter media layer and replenish the missing filter media to the design standard;
Disassemble the filter plate, replace the damaged filter cap and filter screen, and ensure that the support structure is without gaps;
Reduce the backwash intensity to avoid further loss of filter media caused by excessive backwashing.
Filter media loss (filter media particles are present in backwash drainage or effluent).
Causes : Excessive backwashing intensity, damage to filter cap/distributor, and improper selection of filter media particle size.
Solution :
Reduce the backwashing intensity to the standard range for the corresponding filter media, and control the filter media expansion rate to 15%-30%;
Inspect the water distributor and filter cap, repair or replace damaged parts, and ensure even water distribution;
Replace the filter media with one that matches the design particle size, and avoid using excessively fine filter media.
Equipment leakage (water seepage from flanges, manholes, and pipe joints).
Causes : aging of seals, uneven tightening of bolts, corrosion of the housing, and wear of the valve core.
Solution :
Replace the worn rubber gasket and tighten the flange bolts evenly along the diagonal .
Repair the corroded parts of the casing with an anti-corrosion coating; replace the casing if the corrosion is severe.
Repair or replace internal leakage valves, and replace wear-resistant valve cores (such as ceramic valve cores).
Excessive operating noise
Causes : Water flow rate is too fast, air blockage exists in the equipment, and the height of the filter media layer is insufficient.
Solution :
Adjust the valve opening to reduce the operating flow rate to the design rated value;
Open the exhaust valve to release the internal air and prevent air and water from mixing and causing impact;
Add filter media to the designed height to reduce the disturbance of the filter media layer by water flow.
