Abstract: Volatile organic compounds including hydrocarbons, halogenated compounds and other hazardous and toxic chemicals are removed from air streams by contacting the air with a suspension of tiny water droplets sized such that the droplets have an internal pressure significantly greater than atmospheric. The solubility of organic compounds in water droplets and their rate of transfer from an air stream to the droplets increases rapidly as the droplet internal pressure rises. After substantial transfer of volatile organic compounds from the air into the droplets is accomplished, the droplets are separated from the air stream and the resulting liquid effluent is disposed of in a manner which prevents escape of contained contaminant compounds.

Abstract: A control system is provided for a mist scrubbing process in which a gas containing odorous and acidic contaminants is cocurrently contacted in a reaction chamber with tiny droplets of an aqueous reagent to react with and destroy the contaminants. The reagent contains an oxidizing agent and a base and the process is controlled by measuring a property, typically pH, of spent spray liquid settling at the bottom of the chamber. That measurement is used to meter the flow rate of base into the system while at the same time the concentration of an acidic contaminant in the scrubbed gas stream leaving the reaction chamber is measured and that measurement is used to meter the injection rate of an oxidizing agent into the system.

Abstract: 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 H.sub.2 SO.sub.4, 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.

Abstract: Apparatus, particularly adapted to the removal of odorous constituents from waste gas streams, is described. The apparatus comprises a treatment vessel or chamber preferably of cylindrical shape containing a coaxially-mounted exhaust duct which serves also as a columnar support for the chamber top or roof. An odorous gas is introduced tangentially into an upper portion of the reactor and is caused to move in a spiral flow around the central column and to exahust through an exit port into the central duct adjacent the chamber floor. An arcuate, spiral baffle is mounted on the chamber floor and extends continuously from the inner vessel wall to the central duct thereby directing gas flow into the exit port to reduce pressure drop through the treatment chamber. A finely divided spray of a reagent reactive toward the odorous compound is introduced into the chamber through nozzles ringing the chamber wall or mounted in the chamber roof.

Abstract: A jet pump or ejector employing steam as the motive fluid is used to produce a dispersion of fog-like liquid droplets containing a reactive chemical in a gas stream. A solution of the reactive chemical is metered to the suction side of the ejector which discharges into the gas stream. Temperature and relative humidity of the gas stream are maintained at levels whereat the ejector discharge condenses to form very tiny liquid droplets containing the reactive chemical.

Abstract: Apparatus, particularly adapted to the removal of odorous constituents from waste gas streams, is described. The apparatus comprises a treatment vessel or chamber preferably of cylindrical shape containing a coaxially-mounted exhaust duct which serves also as a columnar support for the chamber top or roof. As odorous gas is introduced tangentially into an upper portion of the reactor and is caused to move in a spiral flow around the central column. A finely-divided spray of a reagent reactive toward the odorous compound is introduced into the chamber through nozzles ringing the chamber wall or mounted in the chamber roof. Reagent droplets coalesce on the chamber floor and are removed from the vessel. The treated gas exhausts up the central duct through openings located near the bottom thereof.

Abstract: Particulate laden gas, especially those gases carrying particulates having a size in the micron or submicron range, are removed by humidifying the gas with water and thereafter subjecting the gas to indirect contact heat exchange sufficient to provide an energy transfer for water vapor condensation of at least 5 horsepower per 1000 cfm. Heat exchange is accomlished by passing the gas downwardly through an exchange element having smooth and vertical gas passages of a relatively large dimension.