sentences:  Most venturi systems operate with an L/G ratio of 0.4 to 1.3 l/m3 (3 to 10 gal/1000 ft3) ("Brady and Legatski 1977").L/G ratios less than 0.4 l/m3 (3 gal/1000 ft3) are usually not sufficient to cover the throat, and adding more than 1.3 l/m3 (10 gal/1000 ft3) does not usually significantly improve particle collection efficiency.Venturi scrubbers can be used for removing gaseous pollutants; however, they are not used when removal of gaseous pollutants is the only concern.