Process and apparatus for the removal of fine particulate matter and vapors from process exhaust air stream

A method of attenuating the discharge into the environment of fine particulate matter and vapors emitted from processed polyurethane foam and accelerating the curing of the foam, which method comprises:

• (a) directing an exhaust air stream against a first surface of the polyurethane foam;
• (b) spraying the first surface of the polyurethane foam with water in the form of a mist of fine droplets and in an amount which initially exceeds the saturation point of the exhaust air stream;
• (c) passing the exhaust air stream through the polyurethane foam to thereby entrain the fine particulate matter and vapors in the water droplets;
• (d) passing the exhaust air stream and water droplets from the downstream side of the polyurethane foam into a transfer duct;
• (e) spraying water in the form of a mist of fine droplets into the exhaust air stream from at least one position on the interior of the transfer duct;
• (f) passing the exhaust air stream and water droplets from the downstream end of the transfer duct into a filter chamber having a cross-sectional area in the direction of flow greater than the area of the transfer duct to thereby reduce substantially the flow rate of the water saturated exhaust air stream through the filter chamber;
• (g) passing the exhaust air stream through at least one porous filter medium which is positioned in the filter chamber transverse to the direction of flow to thereby coalesce on the filter medium at least a portion of the moisture in the exhaust air stream;
• (h) collecting the water from the base of the filter medium in the bottom of the filter chamber;
• and
• (i) passing the exhaust air stream from the filter chamber into the atmospheric environment.

Apparatus for removing from an exhaust air stream fine particulate matter and vapors emitted during processing of polyurethane foam comprising:

• (a) a transfer duct adapted to receive an exhaust air stream containing the fine particulate matter and vapors emitted from the processed polyurethane foam, the transfer duct having a given cross-sectional area;
• (b) at least one nozzle positioned on the interior of the transfer duct and adapted to spray water in the form of a mist of fine droplets into the exhaust air stream;
• (c) a filter chamber having an inlet adapted to receive the downstream end of the transfer duct and an outlet, and adapted to receive a plurality of filters positioned transverse to the direction of flow of the exhaust air stream, the cross-sectional area of the filter chamber being substantially greater than the cross-sectional area of the transfer duct so that the linear velocity of the exhaust air stream in the filter chamber is from 0.5 to 0.05 of the linear velocity of the exhaust air stream in the transfer duct;
• (d) a plurality of high surface area organic filters positioned transversely in the filter chamber;
• (e) an exhaust duct adapted to mate with the outlet of the filter chamber for discharging the exhaust air stream into the atmosphere;
• and
• (f) means adapted to move the exhaust air stream through the transfer duct and filter chamber.