Catalytic combustion type exhaust gas processing device and drying furnace for use in coating utilizing the same

A furnace for heating and drying a coating on an object, comprising:

• an enclosure for receiving an object having a coating which is to be heated and dried;
• a recycle loop communicated both at a return duct end thereof and at a supply duct end thereof with said enclosure and incorporating a means for heating in said recycle loop a gas stream being recycled from and to said enclosure, and
• a catalytic combustion-type processing device for exhaust gas discharged from said furnace and which exhaust gas contains volatile noxious or smelly components, said device comprising:
• a catalytic combustion-type exhaust gas-processing device, comprising:
• a catalytic reactor housing comprising wall means defining a chamber having an inlet and an outlet for a gas stream flowing in a direction along a path;
• a first catalyst layer and a second catalyst layer, disposed in said chamber, for being sequentially contacted by said gas stream when flowing in said direction along said path;
• said first catalyst layer being disposed for dehydrogenating into aldehydes noxious or smelly components contained in said gas stream, said first catalyst layer comprising, in sequence along said path, a first sub-layer and a second sub-layer, each said sub-layer comprising at least one platinum group metal selected from the group consisting of platinum, palladium, and mixtures thereof, said at least one platinum group metal being carried on a support;
• said support, in said first sub-layer being made of heat resistant fibers;
• and
• said second catalyst layer being disposed for oxidatively decomposing said aldehydes and comprising a quantum of chemically active copper, and cerium, in the form of a copper-cerium compound, disposed on a second support;
• said inlet of said chamber being in communication via duct means with said enclosure and adapted to receive through said duct means a gas stream withdrawn from said chamber for passage along said path, whereby this gas stream is processed in said chamber and, after being processed, passes therefrom through said outlet of said chamber.