Symptoms
Clogging of the extraction line
Incorrect operation of the extraction sludge pumps
Sand presence in the clarifier
Main causes
High content of sand or clay
Low velocity in extraction sludge line
Investigations and analyses
Measure the sand and clay content in the collected sludge
Evaluate flow velocity in the extraction pipe
Remedial actions
Back-wash the clogged line
Enhance the grit chamber efficiency
Remove the sludge more frequently, trying to remove curves and valves
If needed reduce the sludge pipe diameter