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AUTOMATED Hydra! • 60
PINCH VALVE SYSTEMS Controlled circuitry for any operating requirements • The Massco-Grigsby Hydral-60 System consists of one or more pinch valves with a single automatically operated hydraulic pump. • Hydraulic pump may be operated by electric motor or by air from normal plant supply system. • Valves may be the same or different size. • Valves in the system may be operated simultaneously or independently. • Control valve may be manual or solenoid. • Valves may be coordinated and interlocked with other plant equipment to automatically control tank levels, rate of flow, etc. • Valves are self-supporting and may be operated in any position from horizontal to vertical. • Valves may be independently controlled for normal or rapid closure. • Valves may be held fully open, fully closed, or at intermediate positions. • Remote control to meet individual requirements. • Controls may be included for automatic emergency operation. • 3 " to 14" I.D. sizes, with 50, 100, and 150 psi line pressure ratings. • Temperatures to 200° F.
W R I T E FOR NEW C A T A L O G NO. 609 Manufacturing
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MINE AND SMELTER SUPPLY CO. 3800 RACE STREET · DENVER, COLORADO OFFICES A N D AGENTS IN P R I N C I P A L CITIES Circle No. 38 on Readers' Service Card
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Plating and subsequent washing o f auto b umpers creates l a r g e volumes o f waste liquids for disposal. N e a r l y 2 0 0 gallons of w a t e r a r e needed to process each bumper
as literally hundreds of other items to auto makers. I n fact, Autolite's Sharonville (Ohio) plant has been one of the nation's major producers of chrome-plated automobile b u m p ers. This means disposal problems for large volumes of waste liquid from plating baths, because this process uses about 1000 gallons of water per minute— from 120 to 200 gallons per bumper. T h e waste contains chromic acid, sulfuric acid, dissolved nickel compounds, and other pollutants. If discharged untreated, it would pollute waterways, killing fish and animals as well as corroding bridge foundations a n d other metal structures.
Tried Bisulfite First
At first, as an alternative to emptying the waste into the O h i o River, Autolite arranged to dispose of it through the Cincinnati sewage system. But this was costly—some $40,000 per year. So, six and a half years ago, the firm turned to its own sewage-disposal system. This involved dissolving sodium bisulfite in water and a d d i n g this solution to the waste to reduce hexavalent chrom i u m ion—the major offender—to a trivalent state. T h o u g h this disposal technique saved money, it created some p r o b lems of its own. These included higher m a n p o w e r requirements (for handling the bisulfite, freeing plugged valves), storage difficulties with the solid bisulfite, odor and cor-
INDUSTRIAL AND ENGINEERING CHEMISTRY
rosion hazards, and unreliable a u t o matic application. Consequently, two years ago, Autolite- with a n assist from Ansul Chemical Co. (Marinette, Wis.)—began using a liquid-S02 disposal system for its waste. I n this operation, c h r o m a t e ion ( C r 0 4 = ) reduces to C r + + + u p o n addition of S 0 2 to the acid ( p H 5 or below) solution. Soda ash next precipitates the chromium and other metallic contaminants. Filtration removes these from the liquid which can then be d u m p e d . Liquid SO Soves Labor
First off, labor charges dropped for the SO2 process because reliable automatic control systems with the liquid reactant saved 1000 m a n hours a year, a n d handling and m a i n tenance expenses declined. Also, the odor nuisance disappeared, a n d material costs fell about 4 0 % (liquid SO2 is cheaper t h a n the available SO2 in bisulfite). T h o u g h it cost $1500 to install the new Ansul system, the lower price of liquid SO2 saved $14 pre chrome line operating shift. This recovered the installation price in the first half year. Autolite plant engineer R o b e r t Winston figures that this reduction technique need not be restricted to chrome waste. He sees valuable potentials for l i q u i d - S 0 2 reduction in a wide range of metal-finishing operations involving other such a c tive oxidizers as p e r m a n g a n a t e , nitrates, perchlorates, and peroxides.
