Questions for you….. is the opactiy catalyst?
what color is the opacity? and how long does it take
Some other thoughts alternate ideas:
If the opacity is “Blue/Bluish tint” and it does not dissipate
quickly it could be SO3. The addition of a SOx reduction
additive could help with that.
If it white flakes or snow (but not catalyst) it could be
ammonium sulphate. If you are adding NH3 to the ESP to
enhance the performance of the ESP, there may be too
much NH3 and it is reacting with the sulphur emissions to
form this salt. This is ESPECIALLY true if the ESP is
operating too cold (less than 500 deg F).
This phenomena has been observed in several West Coast refineries.
We have also seen the ammonium salts cover the plates & wires of the ESP
reducing the overall effeciency / effectivness of the ESP.
Check the effectiveness and frequency of “rappers” and “Vibrators” of the ESP.
Check the ESP for Arcs & Sparks (is it tuned effectively/efficiently?).
Check the temperature of the ESP. Catalyst undergoes a historisys. The
amount of charge a catalyst particle can accept decrease as the temperature
of the particle decreases impacting its’ capturability. (Old saying– a HOT ESP
is a HAPPY ESP!).
If it is catalyst check the bed level knowing that a change in catalyst
type or manufacturer can have an impact on the catalyst density
which changes the level readings if the level readings are not compensated
for using actual unit measurements.
Also, check to see the Patricle Size Distribution (PSD) of the freshly delivered
fresh catalyst. IF the unit cyclones are only holding onto 10 wt% 0-40 um and
the refinery is receiving a fine grade (over 16 wt% 0-40 um) many of the light
particles are leaving and ending up as opacity.
Check for sources of attrition.