Document o9vGkny50NMVL5zb28oeBQME3

M iinn \S-W' '^/Z' O'S' V=3 ?==i 'h-'Pi zc D==3 ' Industrial Hygiene Duett May, tap} 452 The Measurement of the Resistivity of Power Station Flue Oust. J. Sei. lnstr. 40. 72-75 (Feb. 1963). l L. Cohen and R. W. Dickinson. The difficulties in obtaining realistic values of the resistivity of power station flue dust are outlined. The principle of operation of the site apparatus described is to sample the dust laden due gases by a suction probe and to extract the dust (n a small, high efficiency, cyclone. The results obtained shew that the resistivity of flue dust undergoes a rapid change with time after its removal from the flue gat stream- Measurements of dust resistivity in the laboratorv can be misleading and only the values measured on site should be considered for design purposes. k* APCA Absts. 453 A Simple Method of Studying the Behaviour of Dust .Particles Flowing Past Obstacles. W. Walkenhorst. Staub 22, 25a-259 (July 1962). German. !-- A laminar stream of dusty air is drawn dpwn a verticle tube having an internal dia meter of 1.5 cm. The air Oows .through a membrane filter which covers the lower end of the tube. If an obstacle such as a wire gauze is placed in the tube a shadow pattern, produced by dust stain, develops on the upper surface of the filter. Ordinary filter papers do not give sharp patterns; only membrane filters are satisfactory. This method makes it possible to demonstrate clearly convection patterns and the dust-free space round heated obstacles. Dust-free spaces due to evaporation of alcohol could also be shown. -. Bull. Hyg, 454 New Way to Sample Industrial Gas Streams. E. A. Wolfe. Air Eng. 4, 24-29 (Dec. 1962). Td determine the amount of particulate matter in an industrial gas stream for pur poses of determining dust loading'. Resign of a dust collector system, etc., the moat important Single piece of apparatus is the filter medium. The filter media used today for gas stream testing have, however, various drawbacks, and it is the purpose of this article to review the problems associated with the use of these filters and to outline the use .of a new'type of filter that largely eliminates thebe problems. Author's summary 455 A New Tool for Air Pollution Control; The Aerosol Particle Counter. W. R. Zlnky. J. Air Poll. Control Assn. 12, 576-583 (Dec. 1962). ' Air pollution control now includes workers in many scientific .disciplines, .in the fields of medicine, space instrumentation, industrial hygiene, environmental control, chemical warfare, and urban air pollution control, there is a common requirement for better instrumentation and labor saving devices to analyte the contents of the air and other gases. Some of the parameters that are of particular interest in each of these fielde are enumerated. $ -- Public 'Health Eng. Absts. 456 Airborne Dust in Foundries. R. Scbardt. Zenlr. Arbeitsmed. u. Arbeitsschutz 12, 157-161 (July .1962). German. Mechanisation of the larger iron foundries has resulted in greater productivity and a corresponding increase in dust in spite of tbe employment of various methods of dust suppression. A series of measurements of dust concentration, with a konimeter-HS, revealed concentrations of dust far above the accepted maximum allowable values; in general, only about 5% of the parti cles counted were larger than 5 microns so that most of the dust measured represented a genuine respiratory hazard. Modern, well-planned plants were the worst offenders In this respect. Local exhaust, enclosure and special attention to troublesome sources pi.dust, such as sand blasting and conveyors, are given as likely targets for new steps in dust suppression. -- Bull. Hyg, . 17. * 031212^3 FOX004889