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N e w Equipment Helps Chemical Process Industry Handle Exhaust Problems Catalytic exhaust unit burns up fumes from gasoline-powered fork trucks Plastics used for ventilator, exhaust systems to handle corrosive fumes
of internal combustion engines adequate safeguards inside plants represents an acute and immediate danger. Now a device has been developed which eliminates the danger from their fumes. Called the O C M catalytic exhaust, the unit was developed by Oxy-Catalyst, Inc., Wayne, Pa. T h e device replaces the ordinary muffler in fork lift trucks a n d other gasoline-powered equipment. It oxidizes the carbon monoxide a n d hydrocarbons in the engine fumes to harmless water a n d carbon dioxide. At the same time, it removes objectionable odors and smoke. H e a r t of the catalytic exhaust unit is a cartridge containing 71 porcelain rods coated with 0.003 inch of catalytic platinum a n d alumina alloy. Each cartridge measures roughly 3 by 5 inches. T h e rods are teardrop shaped in cross section to minimize back pressure. T h e y are staggered in position to present m a x i m u m surface
for combustion of the carbon monoxide a n d other harmful vapors—mostly hydrocarbons—as the exhaust flows across the rods. T h e catalytic reaction which oxidizes the unconsumed carbon monoxide and hydrocarbons takes place at the surface of the rods. T h e catalyst, by its presence in the muffler, combines the contaminants with oxygen at a lower temperature than that which is ordinarily required to cause the reaction. T h u s the catalyst permits combustion of the pollutants at temperatures well within the range of the exhaust gases. Catalytic mufflers are m a d e by encasing the required n u m b e r of catalytic cartridges inside a n explosion-proof steel shell. For gasoline engines, one cartridge is used for about every 35 cubic inches of piston displacement. White gas is necessary with gasoline engines, since lead in automotive fuel will poison the catalyst. T h e catalyst participates b u t is never actually
Cutaway view of a typical O C M catalytic exhaust. Porcelain rods inside the unit are coated with a catalytic agent which oxidizes carbon monoxide and other noxious gases t o harmless carbon d i o x i d e and w a t e r vapor. As engine exhaust enters it draws in air (to support combustion) through circular air filter shown at right
W i t h a very low ceiling, a gasoline fork truck operating in this room at Franklin Research Co. could easily build By up dangerous concentrations of exhaust fumes. equipping the truck with an O C M catalytic purifier, the company is able to operate the truck in low-ceilinged rooms for hours with no ill effects to workmen
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Reported to be the first of its kind in industry, this new polyvinyl (PVC) centrifugal nonoverloading r a d i a l b l a d e d fan is especially made to resist corrosion in moving chemically laden air and gases. Because all parts exposed to the airstream are of PVC throughout, the fan will withstand the corrosive effects of air borne chemicals indefinitely. It is available in sizes from 1 2 " to 4 0 " in diameter
consumed in the oxidation process. OxyCatalyst recommends replacement of the catalytic elements for muffler applications after 2000 to 2500 hours of operation.
Polyvinyl Chloride) Fan for Industry Plastics are beginning to replace metals in some blower installations requiring corrosion resistance. T h e Chicago Blower Corp., Franklin Park, 111., has available an all-poly (vinyl chlo-
Pressure blower with outlet damper made of Hastelloy C and outer shell neoprene-coated; steel 98 A
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ride), centrifugal, radial-bladed fan for moving chemically laden air or gases. T h e P V C fan is designed for use in chemical processing operations where coated metal fans may be affected by strong acids. All parts exposed to the airstream are m a d e of corrosion-proof, unplasticized p o l y v i n y l chloride), including blades, scroll, wheel h u b , and wheel back plate. Special advantages of the all-plastic fan are long life and low cost. T h e initial cost of the P V C fan is less than coated metal a n d stainless steel fans. It is available in several belt driven sizes ranging from 12 to 40 inches in diameter. Another approach to the problem of handling corrosive fumes is to fabricate the blower from a corrosion-resistant alloy. This is the approach the General Blower Co. has taken in designing a pressure blower for corrosive fumes. In constructing the corrosion-resistant blower, General Blower m a d e the outlet d a m p e r of Hastelloy C to handle the specially corrosive conditions. T h e blower shell was m a d e of mild steel coated with neoprene.
Polyethylene Gets in Act, Too Easy maintenance and no corrosion problems are the chief advantages of ventilators and exhaust systems fabricated from polyethylene. T h e American Agile Corp., M a p l e Heights, Cleveland, Ohio, is making the systems in 6-, 8-, 10-, and 12-inch diameter inlet sizes. T h e ventilators are designed to handle static pressures from Vs to 4 inches, and move from 100 to 3400 cubic feet of air per minute, depending on the size used. T h e ventilator housings as well as the rotors are completely constructed of polyethylene, and no metallic parts are exposed to corrosive fumes and vapors that pass through the ventilators.
All-polyethylene ventilators
