June 20, 1931
INDUSTRIAL AND ENGINEERING
Industrial Notes N e w Dorr Classifier T h e Dorr Co., 247 Park Ave., N e w York, Ν . Y., has intro duced for general classification service the Dorr F classifier, developed over a period of three years in anticipation of changes in grinding and classification practice which have now material ized. The motivating influences were, first, the definite tendency towards the maintenance of larger circulating sand loads in con nection with closed circuit grinding, and second, the trend towards coarser separations at the primary classification stage in multiple stage
fine
grinding
CHEMISTRY
197
New Stabilizer for Vibrating Screens A unique stabilizer mounting for vibrator screens has been a n nounced by the Stephens-Adamson Mfg. Co., Aurora, 111., in tended t o prevent the bucking and rocking which s o often result from surges of material over t h e screen. In place of t h e usual balancing springs a t the four corners of the screen, a simple stabil izes unit is mounted upon one side of the frame t o hold the screen at a n unchanging angle. The screen is free t o vibrate with t h e eccentric vibrating shaft, but i t resists the usual tendency to rock or swing out of t h e proper screening angle. T h e stabilizer con sists of two pairs o f short arms, jointed elbow fashion and held pax-allel b y a rigid cross bar. One e n d of each arm pivots on t h e fly-wheel housing, which i s rigidly fastened to t h e heavy steel subframe. The other end of each arm is shackled t o the screen body. The two arms are free t o swing or bend in a n y direction, b u t both must bend and swing together. Industrial Ovens and Driers T h e Freas Therrno-Electric Co., 1206 South Grove St., Irvington, N. J., h a s issued a new 48-page catalog o n industrial ovens and driers. This i s well illustrated and contains a thorough-going discussion of oven construction and t h e basic principles of electric drying ovens and driers. The catalog is divided into three parts, the; first discussing "Electric H e a t versus Fuel Heat," the second, "Basic Principles o f Electric Ovens and Dryers," and the third is a c a t a l o g section d e v o t e d to t h e company's products. TChe Pfaudler C o . , Rochester, N. Y., has announced the follovsring new appointments: Vice president and general sales manager, George F . Kroha; assistant general sales manager, George C . Calvert ; assistant secretary and foreign sales director, Rani et Miner; manager of sales, Chemical Division, Philip S. Baarnes; manager of Midwest Sales Division, "William H . Klee.
Dorr F Classifier
T h e outstanding, feature of the new classifier is a distinctly different type of head motion which is responsible for ability to operate smoothly and quietly at speeds 50 per cent greater t h a n the maximum previously possible. The use of higher speeds has been accompanied by a corresponding increase in sand raking and overflow capacities, where these high rake speeds are consistent with the separation desired. All working parts are constructed of cast steel with a liberal use of pressure -lubricated bearings of the ball or roller type. H e a v y welded construction is used throughout on the steel tank and the recipro cating rake assemblies. N e w Double-Sealed Ball Bearing T h e EEowell Electric Motors Co., Howell, Mich., has an nounced a new double-sealed ball bearing as the standard anti friction bearing o n all its Red Band motors. T h e balls and ball raceway of t h e bearings are packed i n a high-quality con gealed oil and completely sealed at the point of manufacture, eliminating all possibility of in jurious abrasives* entering the Howell Double-Sealed Ball interior o f the bearing in the proc Bearing ess o f manufacture. The seal also prevents foreign material from entering t h e raceway in operation. The motor bearing runs free because of t h e lack of channeling of grease, and excessive pressures caused by over greasing are eliminated. SterliT"" " Κ Ί Λ Ο Λ - Τ Ϊ + Α lWntnr
Sterling Electric M o t o r s , I n c . , 5401 Telegraph Road, Los Angeles, Calif., have d e v e l o p e d a KlosdT i t e e n c l o s e d fancooled motor, as shown in t h e i l l u s t r a t i o n . T w o sturdy iron hous ings completely encase t h e bearings, air gap, r o t o r , and windings. Sterling 3Klosd-Tite Motor Features of the motor are Cros-line starting, improved cast rotors, improved ball bear ings, mica- and asbestos-insulated windings, vapor-resisting, and Directhru ventilation.
TThe N i a c e t Chemicals Corp., Pine Ave. and Forty-seventh St.* Niagara Falls, 3ST. Y., is now producing a grade of paraldehyde conforming t o all t h e requirements of the XJ. S . Pharmacopeia.
l&nlarged Edition o n Analytical Reagents Available Analytical Reageats. Standards and Tests. Published b y Hopk~in and "Williams, Ltd., and Baird and Tatlock (London), Ltd,. 14-17 Cross St., Hatton Garden, London, E . C. 1, England, 1931. xviii + 1 3 5 p p . Illustrated. 14 X 22 c m . T h i s book i s a rewritten and enlarged third edition of Edmund White's book:, "Analytical Reagents, Standards and Tests," published in 1911 b y Hopkin and Williams, Ltd., and adopted as -their standards for the manufacture of analytical reagents. T h e tests a n d standards given for about 180 reagents are n o t greatly different from others t h a t have been published. A list of * 'general conditions" specifies that t h e quantity of chloride represented b y a "faint opalescence" shall he 0.06 mg. of CI and tha.t "a faint yellow colour" in the Nessler test for ammonia shall represent 0.O1 mg. of NH S . Descriptions of "bench re agents" indude t h e strengths of solutions and instructions a s to t h e volumes to b e added in making tests. Directions are given for the G-ntzeit test with the mercuric chloride paper covering t h e top of a tube of internal diameter of 5 mm. so that the evolved gas passes through the disk of paper. Estimates are not given for the possible content of impurities for which the tests prescribe "no> turbidity or precipitate." Definite limits are s e t for arsenic and. for assay. W. D . COLLINS
Solid Carbon Dioxide in a N e w Role K_ecently what might have been a serious accident or waste of valuable material w a s prevented by a n unusual use of solid carbon dioxide (best known under t h e trade-mark Dry-Ice.) The valve in a one-ton tank of liquid chlorine had become so badly stuck that it was feared it might b e damaged by a n effort t o force it open. The hazard of a break was so great that throwing the whole thing i n t o Lake Michigan was seriously considered. However, the use o f solid carbon dioxide t o cool the contents to a safe point (vapor pressure reduced below atmospheric pressure) allowed t h e o l d valve to b e removed safely and a new operable one substituted in the customer's plant without loss of either cylinder or contents. T h e procedure, which may b e used with safety with any vola tile substance» was simply to pack solid carbon dioxide around the cylinder until i t was sufficiently cooled to permit opening it.
