CONDENSATION IN INLET DUCT TO THERMAL OXIDIZER

[roker]

Hello,

How can I eliminate water condensation in the inlet duct to a thermal oxidizer, ambient temp at day is about 30-40 deg. C
and at night can reach 5 deg. C.
Insulation is enough or should I use a condenser with a KOD ?
Regards,
roker

 

[GHartmann]

Please provide a little more information to enable us to help you better:

What is the dewpoint and temperature of the gases entering the oxidizer?
What is the source of the gases?

Have you considered some type of preheater arrangement?

The condenser won't help you with the night time condensation, as you are unlikely to cool your gas below 5 deg C

 

[roker]

Dear GHartmann,

Sorry for the late reply,
we are covering an oil water separator in order to collect the VOC with a blower to the thermal oxidizer, the vapors are not with the same composition so there is no constant or known dew point.
the source are refinery processes.
what is the recommended air flow velocity above the liquid in the separator for not getting entrainment of liquid to the blower and to the thermal oxidizer?
regards,
roker

 

[GHartmann]

This formula will get you the size of the knock out pot:

http://www.eng-tips.com/faqs.cfm?fid=1153

I always used 10 ft/s for the superficial velocity from the liquid surface area.

Have you considered a mist pad or similar device in the gas inlet system?

 

[roker]

Thank you GHartmann,
By separator I meant an oil water separator like an API separator which is 20 by 80 meters concrete pond which will be covered by a fix cover, the vapors will be flowing from the vapor space through openings in the cover via ducts to a blower and to a thermal oxidizer, at the opposite side of these suction openings there are vent openings which allow air to flow into the vapor space of the API separator.
What should be the velocity of the air above the liquid in the API separator so no entrainment of liquid will occur?
In order to protect the blower a KOD will be installed upstream the blower.

Regards,
roker