pH control
The information presented in this section is relevant for XDUO mixer only.
Corrective action
Possible causes
Problem
pH control must use a deadband. If no
deadband is used, acid and base are
alternately introduced. Define a
deadband value appropriate to your
process.
The deadband is set to 0.
pH is not coming
to equilibrium
even if the pumps
are running.
Fill the acid/base supply vessel.
Acid/base supply is empty.
Prime the pumps.
The pumps are not primed.
Free the feed line.
Feed line before or after the pump is
kinked.
Free the feed line.
Feed line before or after the pump is
clamped.
Conduct a study to verify the control
parameters. The following factors have
been identified as important:
PID parameters are not appropriate for
the system.
•
Quantity of media
•
The pump type
•
Concentration of acid and base
•
Mapping strategy
•
Buffering capability of media
•
Mixing of the mixer vessel contents
(weight and viscosity dependent).
Xcellerex XDM 50-1000, XDUO 100-1000 mixers Operating Instructions 29251615 AD
267
9 Troubleshooting
Summary of Contents for Xcellerex XDM Series
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