Two stage odor control system

Odoriferous vapors, such as those from plants for rendering fats, for example, are treated in a two-chamber system. Vapors having a high odor content, such as those from rendering cookers and presses, enter a first high intensity odor treatment chamber at the top, and are treated with a water spray or sprays, the latter containing an oxidant, NaOCl, for example, or H2SO4, at a relatively high concentration of liquid droplets per cubic foot and a relatively longer reaction time in the order of 20 seconds. Treated vapors exit this chamber from its lower portion and are led into a duct conveying low odor intensity vapors, such as rendering plant ventilation odors, into a second, lower intensity odor treatment chamber. The second chamber contains a spray nozzle which sprays water droplets of lesser concentration into the vapors, the said droplets also containing a treating agent. In the second chamber the reaction time is relatively shorter in the order of about three seconds. Treated vapors substantially odor-free are removed from the top of the second chamber.