Fume Collection

[sfsurfer]

How do I determine the amount of fumes I can collect with a vent. The fumes would be emitted in an open area and the vent with the exhaust fan would be 4' away?

 

[CESSNA1]

SFSURFER: Could explain this a little better please. If the fumes are in an open area such as field and the fan is 4' away then you will collect virtually no fules unless the wind blows them there. If the open area is inside a large building then you may or may not collect any fumes. Can you post more details.

Regards
Dave

 

[sfsurfer]

Thanks Cessna1 for the response:

The open area would be about 8' L x 6' W and the fan would be about 30" away. The fan vent would potrude though a plexiglass ceiling (8' L x 6' W). So, the idea is that the fumes will rise then hit the plexiglass ceiling and be drawn accross the ceiling into the fan.

 

[CESSNA1]

sfsurfer: As I see this, there is a plexiglass enclosure 6'X 8' that has either walls with vent openings of no walls (other than support posts). The fan and top of the enclosure are 30" from the source of the fumes. Assuming the fumes are lighter than air and will, therefore rise, then the fan will pick them up and carry them through the duct. To determine the quantity of fumes to be exhaused you need to know the rate at which the fumes rise. This is not easy to determine. The fan flow rate can be determined from the maufacturer and corrected for duct and other losses. If you do not want the fumes to escape, and I assume you do not, then you will need to make sure that air is flowing into the enclosure on all sides; or vent openings are in the encloser sides.

What is this for? It sounds like a vapor extraction system of some sort. Are the fumes being directed somewhere or just dischaged to the atmosphere? It seems like soomething is missing?

Regards
Dave

 

[sfsurfer]

Cessna1:

Yes, you basically understand the enclosure correctly. We have no walls on the four sides just posts to support the plexiglass ceiling. The fumes are 8 CFM of O2 (oxygen) with .08 PPM of O3 (Ozone. They are being emitted from a Corona discharge head and are about 110 degrees when they are emitted from the head. So, I am assuming they will rise even though the O3 is denser than O2. They are being directed to a duct system that will direct the fumes to the outside of the building. This is acceptable because the O3 has a 1/2 life of 30 minutes and eventually reverts back to O2.