Ventilation - 744 entradas encontradas
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Partridge L.J., Nayak P.R., Stricoff R.S., Hagopian J.H.
A recommended approach to recirculation of exhaust air.
The factors to be considered in the design, installation and operation of a recirculation system are reviewed and discussed in this research report. The variables are: overall design; feasibility assessment; contaminant properties; exhaust cleaning; surveillance and response systems; recirculation system design; performance evaluation; maintenance and operation. The appendices, which embody the conclusions of the report, show modeling of a system, equations and calculations for the configurations, and a hypothetical system for vapour degreasing.
DHEW (NIOSH) Publication No.78-124, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, Ohio 45226, USA, Jan. 1978. 184p. Illus.
Düpre G., Graumann K.
Ventilation near road-driving machines with dust control equipment
Die Bewetterung im Bereich von Streckenvortriebsmaschinen mit Entstaubungsanlagen [en alemán]
Auxiliary ventilation measures to be taken during mechanical driving of roadways to ensure effective ventilation: ventilation of areas subject to the simultaneous, conflicting action of auxiliary ventilation and dust control systems; ventilation while the ducting is being extended; ventilation of the coal face. Coanda-effect vortex-flow ducts or supplementary mobile ducts provide a solution to the problem caused by the reduced airflow rate in the area where ventilation and dust control are operative. Air cooling is also dealt with. Formulae and diagrams are given for design of effective ventilation. Measures to control ventilation rate and methane concentrations are set out.
Bergbau, May 1978, Vol.29, No.5, p.188-196, and June 1978, No.6, p.266-272. Illus. 11 ref.
Capture efficiency of a local exhaust system for a hammer drill.
Bestämning av infangningsförmaga - punktutsug till en slagborrmaskin [en sueco]
The dust particle capture efficiency was determined for 2 exhaust flows, 2 drill steel diameters and for horizontal and vertical drilling. An optical particle counter was used in a room with known ventilation when drilling with and without the use of the exhaust system. The measuring method and equipment are described. The models used for converting data to capture efficiency values and the relation between caputure efficiency and reduction of dust level are discussed. The results are presented as capture efficiency values for 5 particle size ranges (0.5-10µm). A simplified description of capture efficiency is used by presenting calculated values for total and respirable dust; these are 99% and 98%, respectively. English summary.
Arbete och hälsa - Vetenskaplig skriftserie 1978:2, Arbetarskyddsstyrelsen, Fack, S-100 26 Stockholm, Sweden. 19p. 4 ref.
National Joint Technical Committees for the Chemical Industry and Woodworking Industry, National Health Insurance Fund (Comité technique national des industries chimiques et Comité technique national des industries du bois, Caisse nationale de l'assurance-maladie), Paris.
Hazards of vinyl chloride in VC polymer processing industries
Risques présentés par le chlorure de vinyle monomère dans les industries transformatrices de ses polymères. [en francés]
Taking as basis the fact that vinyl chloride (VC) polymers, homopolymers and copolymers still contain variable amounts of residual VC monomer, the 2 technical committees involved recommend local ventilation of VC at the source, or otherwise general ventilation of the workplace; or a combination of these 2 solutions to ensure that the air breathed by workers contains a maximum of 2ppm VC by volume in older factories and 1ppm in new ones. Commentaries on these regulations and table showing sources of VC emissions and recommended measures at the different processing steps (transport and storage of PVC, production of blends, handling of hot blends, storage of cold blends, processing of blends, storage of cold finished products).
Cahiers de notes documentaires - Sécurité et hygiène du travail, 1st quarter 1978, No.90, Note No.1109-90-78 (Recommendation No.133), p.167-172.
Practices for ventilation and operation of open-surface tanks.
This standard concerns the protection of operators from contact with gases, vapours, mists or liquids used in or released by open-surface tank operations. It also covers the design of ventilating systems for controlling and removing such gases, vapours or mists but does not cover fire protection. Contents: construction specifications; classification of open-surface tank operations; local exhaust and general ventilation; control requirements (control velocity, enclosing-hood, lateral and canopy exhaust); spray cleaning and degreasing; control means other than ventilation; system design (capacity, static pressure, design, construction); operation (airflow, discharge and recirculation, etc.); personal protective equipment; special precautions for cyanide; installation, maintenance, and inspection of tanks; drainage, etc.; vapour degreasing tanks. Tables: chemical data, flash point, rate of mist evolution; toxic concentrations; classification of operations and airborne contaminants, etc. Diagrams: push-pull ventilation system; enclosing hoods, canopy hoods, rim exhaust, etc.
ANSI Z9.1-1977, American National Standard Institute, 1430 Broadway, New York, N.Y. 10018, USA. Standard approved 4 May 1977. 40p. Illus. 8 ref. Price: US-$6.50.
Elimination of health hazards in pickling plants
Åtgärder mot hälsorisker vid betning av metaller [en sueco]
Methods (enclosure, local exhaust ventilation by hoods or slots) for removal of harmful gases and vapours from the acid baths are discussed. Slot extraction in the most common. Changes in process variables, e.g. reduction of temperature or concentration, addition of wetting agents or inhibitors, were studied; addition of wetting agents to sulfuric acid baths reduced acid mists by 95%. Recommendations for the required air volume to be removed from different baths are given, along with design variables. Instructions for controlling ventilation equipment, measuring pollutant concentration, chemical storage and handling, and preparation of safety sheets for the substances are included. English summary.
IVF-resultat 77504, Sveriges Mekanförbund, Box 5506, 114 85 Stockholm, Sweden, Dec. 1977. 62p. 21 ref. Price: Swe-cr.15.00.
Safety problems concerning equipment for ventilating tank barges transporting flammable liquids on inland waterways
Einige sicherheitstechnische Probleme bei Be- und Entlüftungseinrichtungen an Ladetanks von Binnentankern für brennbare Flüssigkeiten [en alemán]
In the closed tanks of tank barges the inevitable heating (e.g. due to the heat of the sun) causes overpressure which may exceed the pressure at which the mandatory overpressure valves can be opened. The possibility of an explosive atmosphere developing near the tanks depends on the type of overpressure valve. This article considers the advantages of overpressure valves to eliminate explosion hazards, as compared to those of open tanks, and studies chiefly the conditions for the formation of an explosive atmosphere inside and outside the tanks, and the possibility of using flame arresters.
Der Landsteg, 1977, No.2, p.11-16. Illus.
Kohler H., Paul E.
Evaluation of local exhaust equipment by determination of the air flow by a propane tracer method
Bestimmung des Abluftstromes nach der Propan-Tracer-Methode - Beurteilung von Absauganlagen [en alemán]
Description of the principle and measuring equipment: air volume, calculation of exhaust rate, determination of harmful gas concentration in the breathing zone and the workshop. The method, which is based on the use of propane as tracer gas and a flame ionisation detector, was used to study working conditions in hot-box coremaking in a grey-iron foundry. It permits determination of the interference of other equipment and improvement of the exhaust system.
Staub, Dec. 1977, Vol.37, No.12, p.462-464. Illus.
Prevention of methane explosions in the event of untoward stoppage of mine fans
Predupreždenie vzryva metana pri vynuždennoj ostanovke ventiljatorov [en ruso]
Accidental stoppage of ventilation in gassy mines can cause the methane concentration in the coal face to reach explosive concentrations within minutes. The article presents an electric system designed to provide automatic shutoff of the electric power supply in underground worksites in such an event.
Bezopasnost' truda v promyšlennosti, Nov. 1977, No.11, p.53-54. Illus.
Blowing versus exhausting face ventilation for respirable dust control on continuous mining sections.
This report gives the results of several surveys carried out in United States mines. The results, reproduced in 2 tables, show the definite superiority of exhausting face ventilation. However, this system has the following disadvantages: it requires careful installation to minimise leakage; it may cause secondary airflow in the corner of the face, necessitating the use of a diffuser fan for firedamp control; and physical limitations may cause difficulty in using such a diffuser fan.
MESA Informational Report 1059, Mining Enforcement and Safety Administration, Technical Support Center, 4800 Forbes Avenue, Pittsburgh, Pennsylvania 15213, USA, 1977. 11p. Illus.
Ahonen K., Peltonen Y.
Experiments with portable grinding machines having built-in exhaust devices
Käsihiomakoneiden pölynpoistolaitteet [en finlandés]
The dust concentrations and particle sizes in the breathing zone of concrete element workers, as well as of the air passed through various dust filters were determined. The low-volume high-velocity exhaust heads on the portable pneumatic grinders decreased the dust concentrations in all experiments. The dust concentration varied depending on the equipment; in some cases the inert dust and respirable silica dust concentrations were higher than the threshold limit values. The dust concentrations in air filtered by a cyclone were 1-4mg/m3, 90% of particles were smaller than 5µm.
TTL 129, Institute of Occupational Health (Työterveyslaitos), Helsinki, Finland, 1977. 31p. Illus. 10 ref. Price: Fmk.15.00.
Checking performance of local exhaust systems.
Definitions; air sampling and analysis; rules for checking exhaust system (components, layout, drilling of test holes, balancing of system, test forms, periodic checks, interpreting suction pressure readings and estimating control velocities or velocity contours, record filing, etc.); inspection by maintenance engineer; quality design of hoods and ducts, collectors, fan and motor; use of smoke tubes for testing.
Data Sheet 428, Revision A, National Safety Council, 444 North Michigan Avenue, Chicago, Illinois 60611, USA, 1977. 6p. Illus. 9 ref.
Dust-free grinding system
Arbeitsplatzfreundliches Schleifsystem [en alemán]
Presentation of a grinding technique using an angle grinder, and eliminating virtually all the dust produced. The technique is based on the use of perforated abrasive sheets fastened onto the grinding disc, which has corresponding exhaust openings. Advantages of the central exhaust system: dust-free work; no formation of deposits on the abrasive grains, and thus better surface quality; cooling of the abrasive sheet and longer service life; better observation of the surface to be finished; more accurate grinding through flexible abrasive sheets and discs. Description of assembly, uses, materials with which the system can be used, recommended speeds. List of available tools and accessories.
Technische Rundschau, 11 Oct. 1977, Vol.69, No.41, p.29. Illus.
Research Triangle Institute, Research Triangle Park, North Carolina.
The recirculation of industrial exhaust air - Symposium proceedings Oct. 6-7, 1977.
The object of the 10 papers and panel discussion in this symposium (Cincinnati, Ohio, USA, 6-7 Oct. 1977) was to help develop technical criteria for the recirculation. Discussed were decision logic for determining recirculation feasibility; design and performance guidelines for recirculation systems; availability of air cleaning and monitoring systems; maintenance guidelines. Other topics included were legislation, energy management, equipment, foundry operations, and practices and research in Sweden.
National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, Ohio 45226, USA, Dec. 1977. 152p. Illus. 8 ref.
Exhaust ventilation of dust-laden gas - Physical basis and technical execution
Absaugung staubhaltiger Gase - Physikalische Grundlagen und technische Realisierung [en alemán]
In spite of long experience in the field of exhaust ventilation, defective equipment is still found. This study demonstrates that efficient exhaust ventilation systems can be set up observing the laws of physics. Principles of exhaust ventilation and the blowing jet, followed by some examples of application (various exhaust inlets and hoods, conveying of dust-laden gas). The principles of natural ventilation are dealt with in a separate chapter.
Aufbereitungs-Technik, Dec. 1977, Vol.18, No.12, p.659-669. Illus. 14 ref.
Exhaust removal of dusts, gases and fumes, particularly in foundries
Absaugung von Stäuben, Gasen und Dämpfen, besonders in Giessereien [en alemán]
This article recalls the principles of dust control at source, considers flow rates in exhaust ventilation, and presents examples of exhaust hoods and enclosure of workposts with very high dust levels in foundries. These illustrated examples mainly concern fettling, sand preparation, shakeout, and electric induction furnaces.
Giesserei, 3 Feb. 1977, Vol.64, No.3, p.49-53. Illus. 5 ref.
Hayden A.T., Lawrence C.H.
Evaluating a buffing wheel exhaust system.
Dust control was studied with a local exhaust ventilation system, with and without an adjustable tongue on the wheel guard, compensating wheel wear-down and thus reducing the amount of dust-laden air entrained into the room. Particle size distribution and concentration in the breathing zone were determined and total dust volume derived. Dust analyses show that exhaust alone reduced the total dust volume in the breathing zone primarily by removing a small number of the larger particles while the tongue was effective in removing a large number of smaller particles. From the standpoint of respiratory physiology, local exhaust with the tongue is more effective than local exhaust alone.
National Safety News, Dec. 1977, Vol.116, No.6, p.65-68. Illus. 5 ref.
Centreline velocity characteristics of rectangular unflanged hoods and slots under suction.
Measurement of centreline velocities of these hoods (area 25-900cm2; aspect ratio - the ratio of slot length to its width - 1:1 to 16:1) showed that for a given face area and volume flow the velocity at a fixed point decreases as the aspect ratio increases. Design formulae used to predict these velocities are not valid over the range of aspect ratios usually claimed for them, and a new non-dimensionalised formula taking account of aspect ratio is proposed. A nomogram for the ranges covered by the experiments is given.
Annals of Occupational Hygiene, Oct. 1977, Vol.20, No.2, p.141-146. 5 ref.
Ventilation techniques developed in South Africa.
A review of recent developments in mine ventilation techniques in deep gold mines and other minefields in South Africa, with emphasis on general air conditioning in mining (comparison of virgin rock temperatures at various depths, between German, United Kingdom, USA and South African mines, shown graphically); core body temperatures (CBT), wet bulb temperatures (WBT), thermal comfort aspects for creating a more favourable microclimate for mineworkers (WBT above 27.5°C considered hot; CBT of 37° desirable, mine air velocities considered best under 2m/s). Other aspects considered: heat given off by machinery underground; tolerable WBT limits by cooling and ventilation; avoidance of supplementary underground fans; cooling tower; chilled water borne in insulated pipes for deep underground dust wetting; cost aspects. Diagram of a typical underground refrigerated cooling system for deep mines.
American Mining Congress Journal, Oct. 1977, Vol.63, No.10, p.40-44. Illus. 11 ref.
Removal and collection of harmful substances during heat processes by annular exhaust rim and filter-type collectors
Schadstofferfassung und -abscheidung bei thermischen Prozessen durch Ringdüsenabsaugung mit nachgeschaltetem filternden Abscheider [en alemán]
A solution to the difficult problem of collecting dust and smoke produced by non-ferrous metal melting furnaces. In the example presented, lead melting furnaces are equipped with an annular exhaust rim with a duct leading to a polyester felt filter. Results of a technical and hygiene study of the installation show it to be an effective means of improving hygiene conditions; it can be applied to other heat processes.
Staub, May 1977, Vol.37, No.5, p.173-175. Illus. 8 ref.
Gobbato F., Petronio L., Fiorito A.
Exhaust of welding gases and fumes in shipyards
Osservazioni ed esperienze in tema di aspirazione dei gas e fumi di saldatura nei cantieri navali [en italiano]
The concentrations and composition of the welding gases and fumes produced using various types of electrode are analysed. The occupational lung disease hazard is estimated on the basis of the cumulative effect of their constituents (which together are at 300% of exposure limits). The kinetics of welding fumes are examined and a section is devoted to prevention measures: general ventilation, exhaust ventilation at the source (mobile hood), personal protective equipment.
Medicina del lavoro, Jan.-Feb. 1977, Vol.68, No.1, p.22-37. Illus. 36 ref.
A local exhaust system mounted on a gas cutting machine - Protection against heat, pollution, noise and light
Rörligt utsug till skärmaskin - skydd mot värme, luftföroreningar, buller och ljus [en sueco]
Description of a local exhaust ventilation system mounted - after trial and rejection of other systems such as remote control - on a gas cutting machine for large metal sheets. Each cutting torch is enclosed in a water-cooled jacket through which fumes are removed by exhaust ventilation, and which also affords protection against thermal and visible radiation. The jackets are lined with strips of sintered copper which absorb some of the noise. In addition to the exhaust ventilation upwards, an exhaust ventilation carriage moves underneath the rods forming the workpiece table. The movement of the carriage is synchronised with that of the cutting torches. The carriage has water-cooled exhaust rims and a vibrating chute for the removal of cuttings and incandescent particles.
Arbetsmiljö, 1977, No.10, p.18-29. Illus.
Atkins Research and Development, Epsom.
The control of noise in ventilation systems - A designers' guide.
Originally prepared as an internal plant guide, this book provides a general background to noise problems associated with all stages of construction projects. Contents: the design process; ductborne noise; velocity generated noise; duct breakout noise; cross talk, location of silencers; noise to exterior; installation and commissioning. Appendices: sound reduction indices of common structures; absorption coefficients of common internal finishes; silencer selection data; sound power levels of cooling towers and air cooled condensers; computer programmes for noise analysis; fundamentals and terminology.
Published by E. and F.N. Spon Ltd., 11 New Fetter Lane, London EC4P 4EE, United Kingdom, 1977. 107p. Illus. 8 ref. Price: £9.00.
Quinot E., Aubertin G., Fruchard J.L., Roure L.
Removal of workplace pollutants - Comparison of the efficacy of an exhaust slot and a push-pull exhaust system
Captage des polluants au poste de travail - Performances comparées d'une fente d'aspiration et d'une combinaison aspiration-soufflage. [en francés]
First of a series of monographs to be devoted to this question. A mathematical analysis of the air flow obtained using 2 different methods (1) a built-in slot; and (2) a push-pull exhaust system with a blower slot and exhaust hood is followed by a study (also using mathematical formualae) of the relative efficacy of these 2 methods at a work surface placed against a wall or partition. Comparison of the methods shows the greater efficacy of the push-pull system in cases where the source of pollution is very localised and stationary, involving pollutant removal over short distances, whereas the combined exhaust slot with recovery hood is more efficacious in the case of a moving pollution source, involving a wider area for pollutant removal, and has the added advantage of requiring less power to operate at equal pollutant removal rates; it must, however, be carefully designed and requires careful maintenance.
Cahiers de notes documentaires - Sécurité et hygiène du travail, 3rd quarter 1977, No.88, Note No.1070-88-77, p.333-342. Illus. 4 ref.
Armstrong R.F., Kershaw E.J., Bourne S.P., Strunin L.
Anaesthetic waste gas scavenging systems.
The Department of Health and Social Security in the United Kingdom has recommended that waste anaesthetic scavenging systems should be installed in operating theatres to reduce pollution. Tests with 3 passive and 2 active systems are reported. All reduced halothane levels significantly, the combination of an active system and semi-closed circuitry being the most effective. Some of the benefits of a scavenging system may be lost if gases can still escape through leaks.
British Medical Journal, 9 Apr. 1977, Vol.1, No.6066, p.941-943. 13 ref.
Ideal attenuation characteristics of sound attenuators for ventilation and air conditioning plants.
Investigation to develop an attenuator with a performance optimised to match the frequency-related variation of noise reduction required by ventilation and air-conditioning systems. Aspects studied are: noise sources (fans, ducts, terminal box, etc.); system attenuation; weighting system; acoustic frequency analysis of installed systems (low-and high pressure installations, duct in room without an air outlet); calculations from other literature sources. Conclusions: the 250Hz octave band is a critical frequency for the required insertion losses; only slightly higher, or in most cases even smaller, attenuation values are required in frequency bands above and below 250Hz; with conventional absorption silencers, selection depends on the insertion loss at or near the 250Hz octave band.
Noise Control, Mar. 1977. Vol.8, No.3, p.93-97. Illus.
Mayor J.M., Serrano Pascual E.V.
Estudio de la aspiración en las líneas de esmaltado de la industria cerámica
Report on tests to improve ventilation in enamelling shops, where considerable workplace air pollution is encountered. Description, with technical data, of a local exhaust ventilation system developed for the purpose: a variable power fan linked to a wet dust collector. Encouraging results were obtained.
Prevención, Jan.-Mar. 1977, No.59, p.4-9. Illus.
Design of an air recirculation system with regard to pollution
Dimensionering av återluftföringssystem med hänsyn till föroreningsalstring [en sueco]
A mathematical model is proposed for the relations between the proportions of fresh and recirculated air, hood capture efficiencies and air-cleaner efficiencies in recirculation of exhaust air. The model is applicable to both general ventilation systems and local exhaust systems. It is used to illustrate the changes of the mean pollutant concentration, when a local exhaust system with recirculation of cleaned air is to be installed in a room where an air-contaminating process takes place.
Arbete och hälsa - Vetenskaplig skriftserie 1977:1, Arbetarskyddsstyrelsen, Fack, S-100 26 Stockholm, Sweden, 1977. 32p. Illus. 7 ref.
Mücke G., Voss J., Weuthen P.
Ventilation and air-conditioning techniques in South African gold mines
Wetter- und Klimatechnik im südafrikanischen Goldbergbau [en alemán]
Review of technical data on air-conditioning networks and the problems due to depth in mines. In spite of very adequate ventilation air flows, air conditioning is essential for work in these mines. Standard techniques involve installation underground of a cooling unit close to the return air shaft. Description of performance and technical data of cooling plant (turbo-compressors with a power of 1,000-3,000kW, water and air refrigerants), pipework insulation, and costs. The total cooling power in South African gold mines is estimated at 225,000kW. Ventilation and air conditioning are coordinated to keep the wet-bulb temperature below 31°C. Description of a standard acclimatisation method for new miners (8 days in a climatic chamber with an effective temperature of 31°C); evaluation of physical working capacity of Bantu miners.
Glückauf, 16 Dec. 1976, Vol.112, No.24, p.1364-1374. Illus. 6 ref.
Use of the welding arc light in ventilation technology
Ispol'zovanie svetovogo ėffekta svaročnoj dugi v ventiljacionnoj tehnike [en ruso]
This article describes the use of the light emitted by the welding arc to guide the exhaust ventilation equipment along the welding bench. Photoiodes fitted on this equipment detect the movements of the arc light, and the signals are converted to move the exhaust hood. This automation results in greater ventilation efficiency as well as energy savings.
Vodosnabženie i sanitarnaja tehnika, Nov. 1976, No.11, p.27. Illus.
Ivanov B., Bakărdžieva T., Markov P., Dimitrov D.
Study of the dust abating effect of water sprays in mine ventilation ducts
Izsledvane na obezprašavaštija efekt na orositelni ustrojstva văv ventilacionni trăboprovodi v minite [en búlgaro]
When a mine is ventilated by main drawing ventilation or combined primary and auxiliary ventilation, it is often necessary to clean the dust-laden air before its evacuation to another section. This can be effected by water spraying in the suction duct. Description of a device developed in Bulgaria, combining a mist generator (with water and compressed air supply) with a water spray unit installed downstream from it. Tests yielded a 67% reduction in dust levels; water consumption was 6l/min, air pressure 5bar and water pressure 4bar.
Trudove na Instituta po higiena, ohrana na truda i profesionalni zaboljavanija, Sep. 1976, Vol.22, No.2, p.59-67. Illus. 3 ref.
Iliev I., Karlson V., Penčeva V., Stefanova D.
Effect of the surface area of ventilation openings in natural ventilation of hot factories
Vlijanie na plošta na aeracionnite otvori pri estestvena ventilacija na gorešti cehove [en búlgaro]
Evaluation of the results of model studies to determine the effect of air inlet and outlet surface area on the natural ventilation of hot workshops. The ratio of the surface area of ventilation openings to the floor surface, according to air temperature, is considered. The ratio between the surface area of air inlets and outlets should be >1; in the case studied the optimum ratio was 1.7.
Trudove na Instituta po higiena, ohrana na truda i profesionalni zaboljavanija, Sep. 1976, Vol.22, No.2, p.3-8. Illus. 5 ref.
Workplace ventilation and heating seen from the angle of energy saving and recovery
Ventilation et chauffage des locaux de travail associés à l'économie et à la récupération d'énergie. [en francés]
Up to the present, ventilation and heating problems were considered separately, and dust, gases and fumes were removed from buildings directly into the surrounding air. Energy saving policy now necessitates re-examination of this procedure. This well-illustrated booklet contains chapters devoted to various types of ventilation, exhaust ventilation, and heating and air purifying systems used in industrial premises, and comments on techniques which can be used to save energy used for heating: recirculation of air after purifying and, if necessary, reheating; heat recovery by heat pumps and heat exchangers (fluid or direct); recovery of heat from waste combustion. Appended: typical energy recovery systems with profitability calculations. Reference to French legislation on gas and dust removal from workplaces, airborne dust control and combustion installations.
Edition INRS n°532, Institut national de recherche et de sécurité. 30 rue Olivier-Noyer, 75680 Paris Cedex 14, France, Sep. 1976. 62p. Illus. 3 ref.
Faxvall S., Jansson A., Olander L.
Leakage measurement and tightness testing with tracer gas
Läckagemätning och täthetskontroll med hjälp av spårgas [en sueco]
This report describes methods for determining the air tightness and air leakage of rooms by means of mathematical models. The model used for evaluating the air tightness is a standard model for dilution. Since no applicable method exists for measuring leakage, the probable amount of leakage, the lay-out of the ventilation system and the rooms and the desired information must be considered. Results should be presented as the fraction of the contamination that is transferred or as the air flow between the rooms.
Undersökningsrapport AMTV 105/76, Arbetarskyddsstyrelsen, Fack, 100 26 Stockholm, Sweden, 1976. 38p. 5 ref.
Ventilation of underground worksites - Rules for design and operation of ventilation systems
Lüftung im Untertagbau - Richtlinien für die Bemessung und den Betrieb von Baulüftungen [en alemán]
Until now no simple method has been available for designing mine roadway ventilation systems which took sufficient account of the inevitable air losses. Technical difficulties also arose with the introduction of plastic ducts, which are less easy to handle than sheetmetal ducts. These new rules, which have grown out of measurements in underground worksites, aim to provide managers with a manual permitting them to choose the correct dimensions and design of ventilation systems. Contents: ventilation problems in underground worksites; terminology and abbreviations; current design rules; layout and operation; basis of calculations, losses due to friction and leakage; design calculation for typical duct systems; rules for layout and assembly of ductwork; protection of ductwork against deterioration; inspection and control of ventilation.
Dokumentation 19, Schweizerischer Ingenieur- und Architekten-Verein, Postfach, 8039 Zürich, Switzerland, Dec. 1976. 76p. Illus. 14 ref.
Lindenau N.I., Mjasnikov A.A., Maevskaja V.M., Umrihin A.N., Ontin E.I., Gorohov P.V.
Improvement of safety conditions in mines
Ulučšenie uslovij i povyšenie bezopasnosti truda na šahtah [en ruso]
Contents of this handbook: improved air conditioning in hard headings and coal faces; choice of appropriate air conditioning system (with nomograms and example of calculation); effective methane drainage at the coal face; sudden falls of coal and outbursts of gas (mechanism, control measures); infusion of water into the rock; dust control measures during coal-getting by cutter loader (water spray, foam, etc.); origin of spontaneous fires and fire prevention in mines; improved safety of underground haulage (track observation periscope for mine locomotives, automatic coupling, checking for wear of coupling elements).
Izdatel'stvo "Nedra", Tret'jakovskij proezd 1/19, 103633 Moskva K-12, USSR, 1976. 176p. Illus. 27 ref. Price: Rbl.0.62.
"Whirlwind" ventilation system with activation of air turbulence
System wentylacji "wirowej" z uaktywnionym wywiewem [en polonés]
The aerodynamic principle of a physical model of "whirlwind" ventilation is presented with details of design and technical data. The conditions for obtaining air renewal are defined and comparative studies with models are used to show that in spite of the deformation of the physical "whirlwind" model, ventilation and air renewal are better than with the conventional ventilation system.
Prace Centralnego instytutu ochrony pracy, 1976, Vol.26, No.89, p.113-124. Illus. 8 ref.
Recommended practices for testing open hoods and booths.
Periodic testing is necessary to determine if hoods and booths are operating efficiently and according to regulations. The choice of anemometer is discussed and tools needed for the tests are listed. The area around a booth should be checked for proper airflow before testing. Techniques for measuring and calculating airflow in booths and hoods are described.
Plant Engineering, 16 Sep. 1976, Vol.30, No.19, p.138-139.
Ryžkov S.V., Kuličenko V.A.
Air humidification with centrifugal fans
Uvlažnenie vozduha v centrobežnyh ventiljatorah [en ruso]
Results of research on heat and mass exchanges taking place on injection of water into 6 types of centrifugal fans installed on board ships. Presentation of a theoretical method for calculating heat and mass exchanges. Graphic reproduction of the relations between the geometry of the impellors and the characteristics of these fans, and results relating to the increased humidity of the outlet air, reduced air temperature, and efficiency. Experimental results agree satisfactorily with those of calculations.
Sudostroenie, Jan. 1976, No.1, p.21-24. Illus. 5 ref.
Tejf Ė.D, Bogačev V.P.
Characteristics of flow of dust laden hot gases given off during welding in the welder's breathing zone
Harakteristiki pylegazovogo fakela svarki v zone dyhanija rabočego [en ruso]
Results of anemometric and thermometric measurements carried out to determine the flow rate, temperature and geometric pattern of hot gases given off during welding with various types of electrodes and various types of current. Statistical analysis of the results enabled some useful data to be ascertained for the design of more efficient local exhaust ventilation systems.
Sudostroenie, May 1976, No.5, p.54-56. Illus. 6 ref.
Handbook of ventilation for contaminant control (including OSHA requirements).
This profusely illustrated book, intended for industrial hygiene seminars for safety engineers, plant engineers and managers, industrial hygienists and other safety professionals, explains what those responsible for implementing and meeting standards laid down by the U.S. Occupational Safety and Health Act (OSHA) have to know in connection with exhaust ventilation. It gives detailed instructions for designing and installing practical, economical ventilation systems that satisfy OSHA requirements. Topics covered include: how to design an installation that reduces operating costs to a minimum; how to solve problems; troubleshooting and inspecting existing systems; careful ventilation instructions for handling toxic materials; how to design ducts and fans; analysis of current obligations imposed by OSHA ventilation requirements; hazard assessment; how local exhaust systems work; hood selection and design; ventilation systems design; fans; testing. Appendices: symbols and abbreviations; glossary; U.S. threshold limit values, etc. Index.
Published by Ann Arbor Science, P.O. Box 1425, Ann Arbor, Michigan 48106, USA, 1976. 376p. Illus. 147 ref. Price: US-$29.50.
Controlling vapours from open surface vessels.
Tests on canopy hood, "push-pull", rim, and central slot ventilation extraction systems are described. As access was an important consideration, the central slot proved to be the most practical. Air flow rates were varied to determine the most efficient volume required to control vapours under all operating conditions. For "undisturbed" locations (i.e. not subject to cross draughts, etc.) the results yield lower air volumes than given in a previous ACGIH pulication. Design criteria for the central slot extraction system are given.
Annals of Occupational Hygiene, Dec. 1976, Vol.19, No.3-4, p.313-324. 2 ref.
Ventilation of industrial buildings
Be- und Entlüftung von Industriehallen [en alemán]
This article reviews the principles of ventilation systems (fresh air heaters, mechanical ventilation, installations with standardised components, directed ventilation); roof ventilation systems (axial-flow and centrifugal fans, materials, functioning during rain, natural ventilation, vertical and horizontal exhaust ventilation); smoke and heat venting systems (in case of fire); air-conditioning and heat recovery systems.
Zentralblatt für Industriebau, 1976, Vol.22, No.2, p.62-67. Illus.
Fume control in a steel foundry.
Description of a new fume control installation serving 2.5-t electric arc and 3-t induction furnaces. It comprises a mobile extract hood, extract duct work, a fabric filter unit, screw conveyors and associated control equipment. The wheeled hood rolls over and off the furnace on rails. The fabric bag filter can handle 44,000cu.ft (1,240m3)/min. Each compartment houses 192 terylene filter bags (diameter 17.5cm) and automatic control gear allows each compartment to be shaken down singly. Air movement through the filter is by way of a backward bladed centrifugal fan driven by a 125h.p. motor.
Plant Engineer, July-Aug. 1976, Vol.20, No.6-7, p.17. Illus.
Burgess W.A., Murrow J.
Evaluation of hoods for low volume-high velocity exhaust systems.
The advantages (above all good collection efficiency with low exhaust volume) and disadvantages (high resistance, possibility of sucking in metal parts, inconvenient to use with coolants, noise) of these systems are enumerated. A machine-tool simulator designed for preliminary evaluation of the design of extractor hoods is described. 3 hoods were evaluated in a test enclosure, a dioctyl phthalate aerosol being used to simulate the metallic particulate generated during machining. Performance varied dramatically with the exhaust volume, and the importance of hood geometry was very evident from the results.
American Industrial Hygiene Association Journal, Sep. 1976, Vol.37, No.9, p.546-549. Illus. 6 ref.
The design of water-spray ventilators.
The problem of specifying the design of a water-spray ventilator for a given duty is considered. The ability of a water spray to entrain air has been applied in coal mines for local ventilation where only small air flow rates (less than 0.5m3/s) are required. These ventilators, which consist of a spray nozzle mounted on the axis of a tube, find general use on face or heading machines, where the spaces around the cutting head may be inaccessible to the main ventilation and frictional ignition of methane is a hazard. A brief outline of previous investigations on the principles is followed by considerations on the penetration of a jet and its scouring action. The principles of the design of ventilators for free operation are presented, and the manner in which the addition of an external resistance is taken into account is outlined.
Journal of Occupational Accidents, July 1976, Vol.1, No.1, p.9-19. Illus. 6 ref.
Problems of auxiliary ventilation in mechanised tunnel driving
Probleme der Sonderbewetterung bei maschinellem Streckenvortrieb [en alemán]
Considerations on auxiliary ventilation, especially ventilation currents in worksites where wheel-type and boom-type tunnel-cutting machines are employed: conditions during normal ventilation and extension of the ventilation ducting, supervision of ventilation, with rules. Problems associated with dust control equipment are mentioned.
Glückauf, 3 June 1976, Vol.112, No.11, p.655-659. Illus. 9 ref.
Removal of oil mist
Eliminer les brouillards d'huile. [en francés]
This article reviews the hazards and other problems of oil mist in machining shops (respiratory disease, dermatitis, cancer; slippery floor surface; bad lighting due to oil film deposited on lights and windows; fire hazard) and takes stock of ways and means of eliminating oil mist; protection of machine tool operators by screens or exhaust enclosures linked to a local exhaust ventilation system with filter or precipitator air purifying; use of non-pollutant cutting oils; preventive maintenance of machinery to avoid lubricating oil leakages and consequent contamination of cutting oils. In addition to numerous examples, several recently marketed appliances for the suppression of oil mist are described on pp.147-150.
Usine nouvelle, Dec. 1976, p.142-150. Illus.
Soundproofing of electrical auxiliary fans
Insonorisation des ventilateurs électriques d'aérage secondaire [en francés]
General remarks on auxiliary fans as a source of noise and the known control measures are followed by the results of research by the French Coalmining Research Centre (CERCHAR) to develop a standard outlet silencer suited to the great variety of fans used in French coalmines. Test bench and field studies of 3 available models selected in the first instance, and modification of 2 of these, permitted a reduction of 25-35dB(A). Solutions were also found for soundproofing the casing. To forestall loss of attenuation as a result of dust, renovation of the outlet silencers must be planned.
Revue de l'industrie minérale - Supplément Mine, July 1976, No.4, p.170-180. Illus.
Recirculation of exhaust air.
The first part of this document contains the papers given at the seminar (Cincinnati, Ohio, USA, 23-24 Oct. 1975) to review critically the study on development of criteria for the recirculation of exhaust air after cleaning. The papers covered: threshold limit values, cost effectiveness, performance standards, and re-engineering parameters. There were also an overview, regulatory perspective, energy considerations, air cleaning devices, contaminant monitoring, design criteria, foundry operations, and future directions. The second part describes the study. The criteria reflect contaminant toxicity, air monitoring requirements, air cleaning equipment, reliability analyses and theoretical modeling of system performance. Air monitoring equipment should be automatic and specific for individual contaminants, and have back-up systems. Appendices contain a categorisation of 514 workplace contaminants, the rationale for the assignment of contaminants into the several groups and recommendations for air cleaners.
HEW Publication No.(NIOSH)76-186, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, Ohio 45226, USA, Feb. 1976. 269p. Illus. 66 ref.
The facts about fume - A welding engineer's handbook.
An introduction on safety precautions in welding is followed by sections devoted to: airborne pollutants (dustfall; particulate fume; gases); responsibility of management and workers (Health and Safety at Work Act, 1974); sampling of workplace fume concentrations; control of welding fume (general and local exhaust ventilation; fume-extractor welding gun; dust respirator; air-fed welding helmet; self-contained breathing apparatus); hazardous metals; flame processes, manual metal-arc welding, MIG-welding, cored electrode processes (flux-cored wires) (typical fumes and gases; pollutants; precautions); submerged-arc welding; air-arc gouging; welding or cutting coated steels (types of coating; degreasing solvents; precautions; removal of coatings); other processes. There are 3 appendices giving: United Kingdom Factory Inspectorate requirements; TLVs; and extracts from American National Standard ANSI Z49-1-1973 concerning ventilation during welding (in use until a British standard is available on the subject).
Welding Institute, Abington Hall, Abington, Cambridge CB1 6AL, United Kingdom, 1976. 31p. Illus.
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