production f o r u m CONTENTS COSTS
Walter 1. Hardy
Processing peanuts to oil.
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INSTRUMENTATION
63A
B. W. Thomas
Analytical process instrumentation. CORROSION
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69A
Mars 0. Fontana
Testing by electrical conductance. PLANT MANAGEMENT
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75A
C. M. Blair
Training hourly employees
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79 A
ATMOSPHERIC POLLUTION
Catalytic exhaust cleaners.
Louis C. McCabe
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H. H. Schrenk
INDUSTRIAL HYGIENE
Decomposition product hazards. STATISTICAL DESIGN
Direction for R&D..
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87A
W. J. Youden
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PLANT ENGINEERING MEMOS
A controlled chilling system..
NEW PRODUCTS AND LITERATURE.
83A
89A
Oliver Morflt
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93 A
Yours for the asking-an editorial clearinghouse for information on new products and services for the chemical industry.
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97A
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1 10 A-I
READERS’ INFORMATION SERVICE. A guide to products advertised in this issue, compiled b y the editors and advertisers to aid the reader in locating the material and equipmenthe needs
11 1 A
PRODUCT BRIEFS.
A handy reference to last month’s advertisements.
E Q U I P M E N T at M A T E R I A L
O U T L O O K For more efficient filtering, dust collecting: three suggestions x
can be increased by as much as a third and product quality improved by F simplyefficiency putting an automatic flow regulator in the filter discharge line. So claims W. A. ILTER
Kates Co. of Deerfield, Ill., on the basis of recent application studies. The regulator, say Kates engineers, maintains a constant flow through the filter a t the filter’s rated capacity during the entire filtration cycle. By automatjcally compensating for increased resistance caused by filter cake build-upl the regulator will prevent a decrease in flow durina the cvcle. Aceorzing to Kates, use of the regulator (labeled K in the cut) increases filter throughput over a given time, thereby increasing daily capacity. Peak performance can be attained by holding flow rates continuously at a preestablished optimum 1-alue. Operators are freed from making manual adjustments on the pump side of the filter. Because the regulator actually measures the flow on which filter performance depends, Kates claims that it gives better operation than automatic differential pressure adjustment
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December 1955
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
59 A
schemes which rely on indirect flow measurements. Costwise, a single, self-contained regulator has advantages over control arrangements which require several components and separate sources of power. Kates reports that its Type SA regulator has worked well for filter applications in a number of plants. The unit has a five-to-one adjustable range and can handle suspended solids without clogging or inaccuracy. Vertical mounting and straight-through flow allow complete drainage after each filtration cycle as well as aiding in washing.
Removing Submicron Particles. A new scrubber is claimed to remove microscopic solids, fumes, and odors from exhaust gases with high efficiency. The dust’control unit, developed by The Johnson-March Corp. of Philadelphia for use where impurities of extremely low or even submicron particle size are encountered, has operated a t 99% efficiency in tests using dust loadings at 5 grains per cubic foot and with 70% of the material below µn particle size. The Hydro Precipitator scrubber collects dust by compressing exhaust gases through a system of multiple tubes which extend below the surface into a water chamber. Gas entering the reservoir a t high velocity creates violent turbulence in the water, resulting in thorough wetting of the entrained solids so that they agglomerate and settle to the bottom of the tank. Efficient scrubbing action is obtained even with small-particle dusts that are generally considered hard to wet, according to the manufacturer. Moisture is filtered from the cleaned gases before they are exhausted. Sludge can be removed intermittently or continually by manual, hydraulic, or mechanical means. The scrubber unit is available in sizes from 500 to 40,000 cubic feet per minute. Cleaner Air. A process for getting cleaner atmospheric air with conventional air filtration equipment has been developed by Wheelabrator Corp. of Mishawaka, Ind. It is suggested for use where low-voltage electrostatic precipitators or dust collectors using disposable or viscous filters have been employed. Advantages cited by Wheelabrator : extremely high cleaning efficiency, moderate cost, low maintenance expense. The process, which Wheelabrator calls Ultra-filtration, employs conventional dust collectors of the tubular cloth filter type. Filter bags are charged with a filter aid which precoats the filtering surfaces to provide an efficient matrix for collecting fine particles of dust or tarry matter. One application of filter aid is said to last from two to three years under normal conditions. Since shaking the spent filter aid and accumulated dust from the filter bags is the only filter maintenance needed, maintenance costs are limited to infrequent cleaning and recharging of the collector. Experience a t one operating installation handling 720,000 cubic feet per minute of city air indicated a collection efficiency for fine atmospheric dust of better than 99%. Conventional cloth filtration, according to Wheelabrator, removed only 30 to 60% of the total dust. COrrOSiOll Probe. When hydrogen and the impurities in steel get together under certain conditions, hydrogen blisters may form, resulting in dangerous corrosion in tanks under pressure. Houston’s Texsteam Corp. has brought out a warning device that uses a pressure gage to signal this hazard. Texsteam’s hydrogen probe is a seamless carbon steel tube with one end closed and machined to make a thin-walled section sensitive to corrosion. If the right combination of hydrogen ions, sulfides, temperature, and acidic materials occurswithin a tank to penetrate steel and form hydrogen blisters, similar blisters will form first on the thinner wall of the hydrogen probe before causing excessive damage to ENilNG AREA the tank wall. Hydrogen from these blisters will then build up pressure HYDROGEN PROBE on the probe’s gage outside the tank. For additional information on new products turn to N e w Products and Literature page 97A->
