TECHNOLOGY, of nitric acid to higher concentrations of hydrochloric acid inhibits attack, making metal one of f e w useful in handling aqua regia. Copper sulfate and chromic acid are effective inhibitors to reduce corrosion rates in 59c hydrochloric acid. Pitting or localized attack is not as severe upon titanium as may be the case in oiher corrosion resisting metals. Welding does not appear to have a deleterious effect upon its corrosionresistant properties. Intergranular attack has not occurred in commercially pure titanium, even under severe exposures to ferric chloric! e or boiling 65% nitric acid. Commercially pure
grades are sufficiently ductile to be cold formed by drawing, stamping, forming, and spinning. It may also be spot welded easily; resistance welding poses no problem. Corrosion resistance is not reduced at the heat affected zone, so annealing treatments are unnecessary. Titanium lining of steel vessels is an interesting development. Where a final stress relieving is required they are ideal partners. Expansion properties are nearly identical, so distortion is minimized during heat treatment. Further experience in fabrication of these vessels may well make them economically available to chemical industry.
Bad Design Causes Air Pollution Lack of basic design information prevents i m p r o v e ment of combustion units N E W YORK.-A deplorable lack of usable design information prevents development of combustion units that will get maximum value out of fuel and largely eliminate air pollution problems caused by faulty combustion, declares Richard C Corey, Bureau of Mines. Corey told a symposium on air pollution and its control, held at Wagner College, that inclusion of such design features as tangential air jets would contribute to coimplete combustion of troublesome, pollution-causing fuels. Complete combustion*, can b e attained in a single chamber. Use of secondary combustion chambers is superfluous and often harmful, says Corey. "I have never seen an incinerator that did not create a hazard or nuisance at some time," declares William T. Ingram, New York University. The stack may not necessarily be the source of trouble; method of handling waste might be responsible. I n spite of all the excellent work that lias been done in Los Angeles and an expenditure of more than $20 million £n past several years, pollution problem there is worse than ever, says Ingram. Pollution Sources im New York. Over 10 millions tons of bituminous coal, 3 billion gallons o f No. 6 fuel oil, and 1.4 million private autos burning over 1.1 billion gallons of gasoline annually contribute to air pollution problem in New York, says Leonard Greenburg, commissioner of New York's Air Pollution Control Department. There are more than 10,000 flue-fed apartment liotase waste incinerators—notorious pollution manufacturers. 1352
Fuel, design and construction, and operation and maintenance are general fields in which his department concentrates its activities, says Greenburg. Technical knowledge is lacking in design and functioning of incinerators, automobile engines, and other pollution sources. Research lab of APCD is studying these facets of the problem and hopes to contribute to improvement of combustion units. Diesel fuels, in increasing favor for use in buses and trucks, release a large amount of irritating aldehydes. Promising solution to this problem is the use of liquefied petroleum gas. Successful in other cities, use of LPG has been suggested for New York and is being investigated by the department. Strict rules the New York Fire Department has set up for LPG are a deterrent. However, the National Board of Fire Underwriters has promulgated a code for handling of LPG to ensure safety. Half the busses and trucks in New* York now burn Diesel fuel. All new combustion equipment installed in New York must be built in accordance with new specifications developed by Department of Air Pollution Control, says Greenburg. After installation, units are subject to inspection by department inspectors. Punitive Action Gets Results. Immediate improvement can be achieved by use of punitive powers of inspectors. In a recent nine-day drive about 150 summonses were issued. In 1953, 83% more violators received summonses than in 1952, and 114% more convictions were obtained. Last year there were 79% more applications for approval of burner plans. CHEMICAL
Community representatives followed Greenburg during question period and stated their continuing concern over the problem. Greenburg was questioned about a catalytic unit for exhaust of autos and trucks, reputed to convert exhaust gases to carbon dioxide and water. He replied that he had been in touch with manufacturers of this unit but had never seen one. As far as he knew, no one outside of the company had seen the unit.
Ionic Pump An experimental air pump with no moving parts, built by GE, can produce a vacuum as high as one billionth of normal atmospheric pressure. A. M. Gurewitsch and W. F. Westendorp, of company's research laboratory, say the device, known as an ionic pump, may eventually simplify exhaustion of radio tubes and other vacuum tubes. Pumps presently used for the purpose involve streams of oil or mercury vapor. One form of the pump consists of a circular stainless steel box, supported between poles of a powerful permanent magnet and connected to the vessel from which gas is to be exhausted. Inside box is a tungsten ring connected to the positively-charged side of the high-voltage circuit which supplies the pump. Metal walls of box are connected to negative side of circuit. Rough exhaustion of air is accomplished with an ordinary mechanical pump. Then, the ionic pump is connected, current is turned on, and electrical gas discharge occurs. Electrons are attracted toward the tungsten ring, but the field of the magnet causes them to oscillate. During oscillation, electrons collide with gas atoms which become ionized and are pulled toward pump walls. On the way, they contact A. M. Gurewitsch adjusts magnet around vacuum system using ionic pump he developed with W. F. Westendorp at GE's research laboratory. Pump contains no moving parts but produces high vacuum
AND
ENGINEERING
NEWS
NHCH, CH
Versatile inter med iatec f
V^lyents ant acid acceptors
c
ci
I
i
" , c
CI
N-Methylcyclohexylamine Technical
\_ r-i
DU PON T N-METHYLCYCLOHEXYLAMINE TECHNICAL
N,N-Diethylcyclohexylamine Technical
AND RELATED COMPOUNDS
NHCH ,
I
N-METHYLCYCLOHEXYLAMINE TECHNICAL is a water-white liquid with a specific gravity of 0 . 8 6 a t 2 0 ° C . It is soluble in both alcohol a n d ether but only slightly soluble in water. It m a y show traces of cyclohexylamine and N,N-dimethylcyclohexyIamine. N-Methylaniline Technica
S P E C I F I C A T I O N S : Purity: 9 9 % minimum Methylaniline content: 0 . 3 % maximum
N(CH
3
)
2
Distillation range: Distills 5 to 9 5 cc. within 2 . 0 ° C , including 149°C, corrected to 760 m m .
OTHER ALKYLATED ANILINES are
available on request from Du
Pont. Be sure to get in touch with us if your process calls for any
N,N-Dimethylaniline Technical
member of the aniline group. Remember, too, Du Pont has the facilities to develop specific intermediates, custom-made to fit
N H C ,2 H^ 5
I
your requirements. A request on your letterhead will bring complete information. E. I. d u Pont de Nemours & Co. (Inc.) Organic Chemicals Department, Chemicals Division Wilmington 98, Delaware N-Ethylaniline Technical
|ORbANIC JCHpMICALS DEPARTMENT
BETTER THINGS FOR BETTER LI VI N G . . . THROUGH
VOLUME
3 2,
NO.
14
» » * .
APRIL
5,
1954
CHtMISJRY
1353
TECHNOLOGY. carbon plates where they are held. Thus gas pressure is reduced. Absorbed gases c a n be driven out of carbon plates by Keating the p u m p . P u m p is said to w o r k on practically all gases. The GE scientists say that for some special applications, such a p u m p might b e permanently attached to t h e tube in which vacuum must b e maintained. Moisture Determination f o r Circulating R e f r i g e r a n t
FOP 4 0 0 Years iliey guaaiMlecl a secret thai We Will QIVE TbTou... Sound the trumpets for a n early 17th C e n t u r y nobleman — t h e D u k e of Saxony! H e sent a spy t o Bohemia in 1 6 2 0 to learn . . . and distribute to the world . . . the secrets of the original tinplating process which the Bohemians had jealously g u a r d e d for over 4 0 0 years! Perhaps possessing more " s e c r e t s " regarding tin a n d tin chemicals t h a n any other source, is M e t a l & T h e r m i t Corporation . . . secrets t h a t we will be glad to give you the benefit of, if tin in any form has a place in your p r o c essing or manufacturing operation. ***« M&T
Means
TIN
Metal & Thermit Corporation has been headquarters for tin and tin chemicals for nearly half a century. Many ne*w tin chemicals have been developed by us lately that may have a bearing on your costs ;iMETAL^#THERMiT; and problems. K;J*fon*ersin* ^ If tin in any form has a place in your processing or manufacr.' THERMIT WEUDINGlS turing operations, we shall be glad to discuss the matter with you. :,: /PLATING /.iTlfcl uuf & Write today. :ANTIMONY;CHEMICALS
METAL & THERMIT ZORPOR&TiIONI
100 East 42nd Street. New York 17. N. Y.
1354
CHEMICAL
Simple, rapid method for determining the water content of a circulating refrigerant of the fluorocarbon group comes from National Bureau of Standards research. Based on change in electrical resistance of a n electrolytic film as it absorbs water v a p o r , m e t h o d is an application of electrical conductivity method for determining water vapor in gases. Method is sensitive, gives accurate results, d o e s not require removal of a sample from circulation cycle. Thin film of hygroscopic material— usually a mixture of sulfuric a n d phosphoric acids—is spread over surface of solid insulator between metallic electrodes in a pressure-tight enclosure. Electrolyte tends to reach equilibrium with the water vapor in the surrounding gas and t o form a solution whose electrical conductance i s a measure of the concentration of water vapor in the gas. Conductance is indicated b y a simple electronic circuit and microammeter. Gas of known moisture content is used to calibrate t h e film after each reading. By adjusting pressure of the comparison gas until same conductivity reading is obtained for b o t b known and unknown gas, two gases can b e m a d e to have the s a m e w a t e r concentration. Unknown water content can then be calculated from the two pressures and the known w a t e r content of the comparison gas at atmospheric pressure.
• Effectiveness of clay c o a t i n g groundwood papers w a s emphasized by tests at National Bureau of Standards. Coating gives considerable protection against degrading effects of light. Nevertheless, such papers are still much less stable t h a n good quality papers without coating. • Flow properties of mixtures cf powdered solids i n nonaqueous liquids have been investigated by Road Research Laboratory, D e p a r t m e n t of Scientific and Industrial Research, London. Road Research Technical Paper No. 28 is described as being of interest to specialists in road field and other industries concerned w i t h the use of fine mineral powders. Copies of t h e paper may b e AND
ENGINEERING
NEWS
*t ^ E ^ W S f ^ ^ ^ S ^
_:~ ,-«.^3&R
* rasraiKi Ir^JRn fp S i « f ^r
rmM
~*.
100% Permanently Plasticized Copolymers By Using Rohm & Haas Acrylate Monomers You can permanently plasticize many polymeric products with Rohm & Haas acrylate monomers. These monomers copolymerize with vinyl chloride, vinyl acetate, vinylidene chloride, acrylonitrile, or styrene—therefore cannot be extracted by even t h e strongest solvents, will not migrate or volatilize. Films and coatings, for example, will not become brittle with age. Food products will not be contaminated by acrylate-plastkized wrappings. Monomers such as methyl acrylate, ethyl acry-
late, butyl acrylate, and 2-elhylhexyl acrylate are a few of t h e Rohm & Haas monomers which can be used. Often, an acrylate may serve as the only plasticizer; sometimes, simply to reduce t h e a m o u n t of external plasticizer required. Moreover, acrylic monomers: 1) permit lower processing temperatures, 2) increase flow so that films can form at lower temperatures, and 3) impart resistance to deterioration by heat a n d light. Write Dept. SP for 38-page booklet on acrylic monomers.
Look to Rohm & Haas Company for acrylic monomers: Methyl acrylate Ethyl acrylate Butyl acrylate 2-Ethylhexyl acrylate Methyl methacrylate Ethyl methacrylate
Butyl methacrylate Hexyl methacrylate Decyl-octyl methacrylate Lauryl methacrylate Stearyl methacrylate Glacial methacrylic acid
FOR INDUSTRY
CHEMICALS
ROHM £ HAAS COM
MY
WASHINGTON SQUARE, PHILADELPHIA 5, PA. Representatives
in principal
foreign
countries
TECHNOLOGY. ^>V
obtained from the DSIR, Charles House, 5-11 Regent St., London, S.W.I., England.
js?
^ * **
• Phenolic materials must be designed out of hazardous applications on aircraft, say T. J. Martin and R. L. Hauter, Boeing Airplane. Concentration of electric power at higher voltages in today's airplanes may constitute fire hazards, they told Society of Plastics Engineers, when phenolic materials are used in applications such as blocks supporting current limiters. Interest in problem was stimulated by fires severe enough to burn large holes in aluminum supporting structure of laboratory mockup of an electric system.
Propulsion w i t h Peroxide Hydrogen peroxide will b e used to propel the British submarine Explorer, here being launched at the yard of Vickers-Arnistrong, Barrow-in-Furness. reports say submarine will be able to cruise submerged for thousands of underwater speed is likely to be 20 to 3 0 knots per hour, and a new technique, employing marker buoy which sends out distress signals, will be Use of hydrogen peroxide as propulsion agent was developed from a German
NIGH
AND
LOW
shown Press miles, escape used. secret
TEMPERATURES
NEW BENCH-TYPE TEST UNIT 1MOI
MARK R C G l S T C R t O
COMPLETE TEMPERATURE RANGE
TESTING UNITS
Combine high and low temperatures within the same cabinet with all controls self contained. Unit measures 5 0 " x 2 8 " x 2 0 " with a testing chamber 1 2 " x l 2 " x l 2 " . Temperature range is from -80° F., to 185° F. Heat application is accomplished with reverse cycle refrigeration, which eliminates the hazards associated with open heating elements. A blower is provided for even distribution of temperatures and greater testing accuracy. Latch-type or hinge-type door optional. Accelerated pull-down to -80° in 30 minutes or less. Write today for more complete information
INDUSTRIAL
WEBBER
FREEZER
MANUFACTURING
DIVISION
COMPANY,
INC.
( Formerly Webber Appliance Co., Inc.)
2741
1356
MADISON
AVENUE
•
INDIANAPOLIS
3,
INDIANA
CHEMICAL
• Draping qualities and stiffness of fabric when flexed by hand are tested with device developed at Navy's Clothing Supply Office. Six-inch strip of fabric is projected horizontally over a platform until free end drops under its own weight to a prescribed angle. Drape stiffness is one half projected length of fabric as read from a scale. This value when combined with weight of sample in a suitable formula gives flex stiffness, resistance of fabric to flexing when supported by hand. • Supersonic
hypodermic
device,
which hurls a tiny liquid column a t 1.75 times the speed of sound and is capable of penetrating four inches of tissue, has been developed at UCLA's atomic energy project. Device may be applicable to direct injection into internal organs and tumors. In operation, liquid in a steel chamber is propelled through a 0.005-inch nozzle by explosive action of a small nitrosoguanidine wafer detonated bv small soldering iron. • C o n t i n u o u s f i l t r a t i o n s y s t e m has e l i m i n a t e d contamination of oil u s e d a s coolant in grinding operations at G e n eral R a i l w a y Signal. Previously, m e t a l particles in oil b e c a m e i m b e d d e d in surface of grinding w h e e l causing impaired product finish. Grinder s u m p s h a d to b e cleaned each w e e k a n d 2 2 0 0 gallons of oil discarded. After installation of a Hoffman Flotation Clarifier, oil replacement w a s necessary o n l y o n c e in eight months and s u m p s required n o cleaning. ^ Electronic t h e r m o s t a t is used at N a tional Bureau of Standards as a generalp u r p o s e temperature controller for a variety of applications. D e v e l o p e d b y F . A. Ransom at N B S , unit features heating element power supply w h i c h s w i t c h e s on and off in a regular c y c l e . Fraction of cycle during w h i c h p o w e r remains o n is proportional to the d e v i a tion from desired temperature.
AND
ENGINEERING
NEWS
