Environmental Engineering Reference
In-Depth Information
Corrective actions:
Change chemical dosage; decrease feed for
a few cycles, then optimize; wash filter media; wash media with
inhibited hydrochloric acid.
•
symptom 6.
Plate press experiencing frequent media binding.
Causal factors:
Inadequate precoat; initial feed rate too high (no
precoat)
Corrective actions:
Increase precoat; reduce feed rate and
develop initial cake slowly.
•
symptom 7.
Plate press is experiencing excessive moisture in the
cake.
Causal factors:
Improper conditioning; filter cycle too short
Corrective actions:
Change chemical dosage; lengthen filter
cycle.
•
symptom 8.
Sludge is blowing out of plate press.
Causal factor:
Obstruction between plates
Corrective action:
Shut down feed pump, hit press closure drive,
restart feed pump, and clean after cycle.
•
symptom 9.
Plate press is experiencing leaks around lower faces
of the plates.
Causal factor:
Wet cake soiling media on lower faces
Corrective action:
See “Plate press is experiencing excessive
moisture in the cake” entry above (Symptom 7).
•
symptom 10.
Filter cake discharge in belt press is difficult.
Causal factors:
Wrong conditioning chemical; improper chemical
dosage; changing sludge characteristics; wrong application point
Corrective actions:
Change conditioning chemical; adjust
chemical dosage; change chemical or sludge; adjust application
point.
•
symptom 11.
Sludge is leaking from belt edges in belt press.
Causal factors:
Excessive belt tension; belt speed too low; exces-
sive sludge feed rate
Corrective actions:
Reduce belt tension; increase belt speed;
reduce sludge feed rate.
•
symptom 12.
Belt press filter cake has excessive moisture.
Causal factors:
Improper belt speed or drainage time; wrong condi-
tioning chemical; improper chemical dosage; inadequate belt wash-
ing; wrong belt weave or material
