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Articles 170221 - 170250 of 198087

Full-Text Articles in Engineering

The Application Of Variable Frequency Drives To Mine Fans, Robert Z. Smith Jun 1999

The Application Of Variable Frequency Drives To Mine Fans, Robert Z. Smith

U.S. Mine Ventilation Symposium

During the past several years variable speed drives have become much less expensive for higher horsepower applications. This has created an opportunity to utilize this type of system in variable load mine ventilation applications where the traditional solutions were to use "in-flight" controllable pitch fans, variable inlet vanes or constant load systems and ignore the opportunity for power savings. This paper explores the basic characteristics of each type system and some of the advantages that each system offers for specific mine ventilation applications. The relative capital cost and operating cost of each type systems are also presented.

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Anti-Stall Fans For The Mining Industry, Phil Blankenship, Hakan Bard, Robert Z. Smith Jun 1999

Anti-Stall Fans For The Mining Industry, Phil Blankenship, Hakan Bard, Robert Z. Smith

U.S. Mine Ventilation Symposium

Stable performance of mine ventilation fans is important not only for maintaining adequate ventilation of the mine, but also to maintain the integrity of the fan unit itself. It is demonstrated, herein, that a properly designed and applied stabilization device, integrated into the fan casing itself, will assure stable performance and actually extend the fan's capability.

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Improving The Ventilation Efficiency Of Jet Fans In Longitudinally Ventilated Rectangular Ducts, Eddy Jacques, Pierre Wauters Jun 1999

Improving The Ventilation Efficiency Of Jet Fans In Longitudinally Ventilated Rectangular Ducts, Eddy Jacques, Pierre Wauters

U.S. Mine Ventilation Symposium

The performance of a jet fan in a longitudinally ventilated tunnel is significantly reduced by the proximity of wall or ceiling where important shear stress losses occur. The paper focuses on the effect of jet fan inclination on the reduction of these losses; reducing losses means improved installation efficiency manifested by increased ventilation flow for the same fan power input. Experimental tests were carried out on a model at scale 1/5.5th. They allow one to determine the optimal jet pitch angle and the resulting benefit that could be drawn out of this solution in the case of tunnels …

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Evaluation Of Different Airflow Sensors At The Wipp Facility, Kirk Mcdaniel, Ian J. Duckworth, Brian S. Prosser Jun 1999

Evaluation Of Different Airflow Sensors At The Wipp Facility, Kirk Mcdaniel, Ian J. Duckworth, Brian S. Prosser

U.S. Mine Ventilation Symposium

The Waste Isolation Pilot Plant (WIPP) is an U.S. Department of Energy underground disposal facility designed to permanently and safely isolate U.S. defense-generated transuranic radioactive waste. The underground ventilation system is engineered to minimize the release of radioactive contamination to the environment in the event of an accident. During 1994 an extensive ventilation remote monitoring and control system was installed. It consists of fifteen air velocity sensors, eight differential pressure stations, automated control features on key underground air regulators, and eight psychrometric stations. The airflow monitoring component of the system has been a problem since the original installation. Due to …

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A Navigating System For Ventilation Network Spatio-Temporal Control, Yuusaku Tominaga Jun 1999

A Navigating System For Ventilation Network Spatio-Temporal Control, Yuusaku Tominaga

U.S. Mine Ventilation Symposium

This paper presents a navigation system for spatio-temporal control of mine ventilation network to help keep miners safe in mine emergency situations such as mine fire, spontaneous combustion, and gas emission. The system is composed of sensors, computer simulation and binary controllers. The ventilation sensors are placed in specific branches of the ventilation network to monitor ventilation parameters such as air velocity. The Horonai coal mine, Hokkaido, Japan is used as an example to illustrate the applicability of the navigation system as on and in providing a safe evacuation route and to estimate the time interval to achieve steady airflow …

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Expert System For Mine Supervising Staff Fire Hazard Monitoring And Fire - Fighting, Waclaw Dziurzynski, Stanislaw Wasilewski Jun 1999

Expert System For Mine Supervising Staff Fire Hazard Monitoring And Fire - Fighting, Waclaw Dziurzynski, Stanislaw Wasilewski

U.S. Mine Ventilation Symposium

The paper presents the functions of an expert system designed for mine supervising staff responsible for fire hazard monitoring and fire-fighting. The essence of the system is to gather the complete data from hazard monitoring systems and the results of manual measurements made by ventilation staff in a common database. The database can be used for analysis and engineering calculation employed in mine ventilation supervision and also for the prevention against natural hazards, in particular fire and methane. Hardware and software tools developed within the framework of the system will also be used during rescue operation.

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High Speed Monitoring And Control System Uses Windows-Nt, Albert E. Ketler Jun 1999

High Speed Monitoring And Control System Uses Windows-Nt, Albert E. Ketler

U.S. Mine Ventilation Symposium

Millennia-DX™ is an advanced monitoring and control system especially designed for underground mining. An inexpensive 233+ Pentium computer running Windows-95 or -NT provides vast processing power that was unheard of just a decade ago. Engineered in-house from the ground up, Rel-Tek's new 32-bit Millennia-Dx™ software code now permits 10-mile data acquisition at an accelerated 115.2 KHz. New techniques and hardware have resulted in a totally integrated hardware/software package with uncompromising performance, features and reliability. A large coal mine installation is highlighted which installed a Millennia-DX system for monitoring carbon monoxide, but soon discovered the "data mining" capabilities which they enlisted …

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Validation Of Computational Models Of Auxiliary Ventilation Systems With Experimental Data, K. W. Moloney, D. M. Hargreaves, I. S. Lowndes, W. Pearce Jun 1999

Validation Of Computational Models Of Auxiliary Ventilation Systems With Experimental Data, K. W. Moloney, D. M. Hargreaves, I. S. Lowndes, W. Pearce

U.S. Mine Ventilation Symposium

This paper reports the interim findings of a research program whose objective is to determine whether Computational Fluid Dynamic (CFD) models can be employed to accurately predict the airflow patterns within rapid development headings. In particular, the project aims to investigate the optimum set back distances for the ducts in order to adequately ventilate the face of the drivage. To validate the accuracy of the CFD model simulations measurements were obtained from a series of experiments performed on both scale models and within a full-scale surface gallery. The experimental scale-modeling program included making a series of pressure measurements across the …

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Radiological Modelling Software For Underground Uranium Mines, Brian Bjorndal, Reza Moridi Jun 1999

Radiological Modelling Software For Underground Uranium Mines, Brian Bjorndal, Reza Moridi

U.S. Mine Ventilation Symposium

The Canadian Institute for Radiation Safety (CAIRS) has been developed computer simulation software for modelling radiological parameters in underground uranium mines. The computer program, called 3d RAD, allows radiation protection professionals and mine ventilation engineers to quickly simulate radon and radon progeny activity concentrations and potential alpha energy concentrations in complex mine networks. The simulation component of 3d RAD, called RSOL VER, is an adaptation of an existing modelling program called VENTRAD, originally developed at Queen's University, Ontario. Based on user defined radiation source terms and network physical properties, radiological parameters in the network are calculated iteratively by solving Bateman's …

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Increasing Energy Efficiency Of Mine Ventilation Systems, Riyaz Papar, Andrew Szady, William D. Huffer, Vern Martin, Aimee Mckane Jun 1999

Increasing Energy Efficiency Of Mine Ventilation Systems, Riyaz Papar, Andrew Szady, William D. Huffer, Vern Martin, Aimee Mckane

U.S. Mine Ventilation Symposium

Every year the United States mining industry spends millions of dollars on underground ventilation systems. In the U.S., fan systems used for mine ventilation consume approximately 12,000 million kWh annually (Xenergy, 1997, 1998). Potential motor-driven system energy savings can be realized by using mature, proven, and cost-effective technologies. Such saving potentials exist in the mining industry and the U.S. Department of Energy's Motor Challenge program aims to assist the industry in capturing them. Energy efficiency upgrades can also achieve significant non-energy benefits such as better equipment reliability, longer equipment life, reduction in maintenance costs and downtime, and an improved working …

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Msha Approval Process, David C. Chirdon Jun 1999

Msha Approval Process, David C. Chirdon

U.S. Mine Ventilation Symposium

The hazardous nature of the underground mining environment necessitates the use of equipment and mining products designed to ensure safe usage in this hostile environment. Title 30, code of federal regulations (30 CFR) includes requirements that all equipment and products intended for use in potentially gassy areas of underground mines be approved by the mine safety and health administration (MSHA). Design and performance requirements for many of the products intended for use in the underground environment are also part of 30 CFR. This paper describes the processes available to potential applicants for obtaining MSHA approval. Emphasis is placed on ventilation-related …

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An Integrated Strategy For Emergency Egress From An Underground Metal Mine, Rick Brake Jun 1999

An Integrated Strategy For Emergency Egress From An Underground Metal Mine, Rick Brake

U.S. Mine Ventilation Symposium

The fact that major fires are rare events in underground metal mines means there is often little on-site experience in dealing with these situations. Elaborate strategies that rely on a high degree of training at all levels to be effective are likely to fail, especially with the trend in Australia towards smaller mines and "fly in-fly out" operations. A robust strategy is required. The key items in such a strategy are: early detection and warning of personnel, personal belt-worn oxygen-generating self-rescuers, high integrity escape routes and self-contained refuge stations, simple procedures, reliable personnel ''tagging" systems and sufficient, trained, search and …

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Gas Emission Control On Longwall Panels At The Vorkuta Coal Mines, V. N. Bobrovnikov, O. I. Kazanin, A. P. Veselov Jun 1999

Gas Emission Control On Longwall Panels At The Vorkuta Coal Mines, V. N. Bobrovnikov, O. I. Kazanin, A. P. Veselov

U.S. Mine Ventilation Symposium

The characteristics of geological conditions and mining technology at the coal mines of Coal Stock Company Vorkutaugol are given in the article. Information about longwall panel ventilation schemes and problems caused by high methane emission is also presented. The results of experiments at longwall panels using the methane emission control ventilation complex are described as well as ways of isolating gob methane removal. Other topics include the methane emission control ventilation complex consisted of drainage entry, an isolating wall with windows, mixing chambers and regulating stoppings. As results of experiments have shown, the most effective gas emission control methods were: …

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Characteristics Of Airborne Dust In The Return Airways Of The Mechanized Longwall Face, Tevfik Güyagüler, Sinan Keskin Jun 1999

Characteristics Of Airborne Dust In The Return Airways Of The Mechanized Longwall Face, Tevfik Güyagüler, Sinan Keskin

U.S. Mine Ventilation Symposium

In this paper the results of a research study on the characterisation of airborne dust in the return airway of the mechanized longwall face at Middle Anatolian Lignite Mine, OAL are presented. Dust, temperature, moisture and air velocity measurements were carried out in the return airways of the fully mechanized longwalls. Then the analyses of results on real-time concentration data, mass concentration data, effect of moisture, heat and air velocity on dust concentration are made. It has been found that amount of dust in return airway is directly related to the face activities and to the amount of settled dust …

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Mitigation Of Methane Emissions From Coal Mine Ventilation Air, Peter Carothers, Milind D. Deo Jun 1999

Mitigation Of Methane Emissions From Coal Mine Ventilation Air, Peter Carothers, Milind D. Deo

U.S. Mine Ventilation Symposium

U.S. EPA's coalbed methane outreach program, (CMOP) has prepared a technical assessment of techniques that combust trace amounts of coal mine methane contained in ventilation air. Control of methane emissions from mine ventilation systems has been an elusive goal because of the magnitude of a typical airflow and the very low methane concentrations. One established and cost-effective use feeds the air into a prime mover in lieu of ambient combustion air. This method usually consumes just a fraction of the flow available from each ventilation shaft. The authors evaluated the technical and economic feasibility of two emerging systems that may …

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A New Laboratory Technique To Estimate Gas Diffusion Characteristics Of Coal, Satya Harpalani, Shaofan Ouyang Jun 1999

A New Laboratory Technique To Estimate Gas Diffusion Characteristics Of Coal, Satya Harpalani, Shaofan Ouyang

U.S. Mine Ventilation Symposium

This paper describes a new experimental technique developed to measure the diffusion coefficient (D) for a coal-methane system using the transient flow mechanism, and examine its dependency on factors that change with continued flow – pressure and gas concentration. Although developed primarily for coalbed methane reservoirs and coal in the gob regions, it also has application in situations where a second gas is injected in coal since it utilizes the principle of counter-diffusion. The results show that there is a continuous decrease in the value of D with decreasing mean concentration of methane in coal. The logarithm of D varies …

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Increased Methane Emissions For Mechanical Miners Working In Burnt Coal, A. P. Cook Jun 1999

Increased Methane Emissions For Mechanical Miners Working In Burnt Coal, A. P. Cook

U.S. Mine Ventilation Symposium

An intensive research programme has quantified the methane conditions around mechanical miners in production conditions. Methane seam gas contents show an increase of up to 26 times when mining burnt coal compared with normal increase in emission rates. Coal seam methane contents at the face increased from 1 m3/t to 6m3/t in one section, and from 0.1 m3/t to 2.6 m3/t in another. Emission rates from burnt coal were as high as 300 lit/min as it was mined. These increases in content and emission occur immediately after cutting into the burnt coal. …

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Economic Analysis Of Coalbed Methane Drainage Systems For Room-And-Pillar Operations, Yanbei Wang, Jan M. Mutmansky Jun 1999

Economic Analysis Of Coalbed Methane Drainage Systems For Room-And-Pillar Operations, Yanbei Wang, Jan M. Mutmansky

U.S. Mine Ventilation Symposium

The analysis of the economics of methane drainage operations in traditional room-and-pillar coal mining operations is the primary emphasis of this presentation. The paper analyzes the economic effects of ventilation costs versus drainage costs as a means of handling the methane in a hypothetical room-and-pillar operation. However, the effects of downtime savings due to methane reduction in the air stream and the impacts of marketing the methane are also studied. Comparisons are then made with the economics of drainage in longwall mining.

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Methane Concentration At Heading Faces With Auxiliary Ventilation, Shinji Tomita, Kenichi Uchino, Masahiro Inoue Jun 1999

Methane Concentration At Heading Faces With Auxiliary Ventilation, Shinji Tomita, Kenichi Uchino, Masahiro Inoue

U.S. Mine Ventilation Symposium

Three-dimensional airflow velocities at a heading face by a forcing or exhausting auxiliary ventilation system were measured in an actual size model gallery and in an actual mine. There were several stagnated regions near the roof comer, which might have danger of methane accumulation. Airflow velocities by an exhausting system were much smaller than that by a forcing system. The airflow and methane concentrations by a forcing, exhausting, or combined system were examined using a visualization technique by laser light in a reduced scale model. Water was used instead of air and very fine bubbles generated by electrolysis were employed …

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Lowering Respirable Dust Exposures At Mineral Processing Facilities, Andrew B. Cecala, Robert J. Timko, Edward D. Thimons Jun 1999

Lowering Respirable Dust Exposures At Mineral Processing Facilities, Andrew B. Cecala, Robert J. Timko, Edward D. Thimons

U.S. Mine Ventilation Symposium

This article discusses three research projects performed by the National Institute for Occupational Safety and Health, (formerly the Bureau of Mines), that reduce the respirable dust exposure of plant workers at mineral processing facilities. All three of these projects are very different but they all have the same goal of reducing worker exposure to respirable dust at mineral processing facilities. The first project deals with a total mill ventilation system that reduces dust levels throughout an entire building and lowers the dust exposure of everyone working in the structure. The second project describes a bag and belt cleaner device that …

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Measurements Of Dust Extraction Effectiveness On A Testing Stand, Walenty Frydel, Marcin Steindor Jun 1999

Measurements Of Dust Extraction Effectiveness On A Testing Stand, Walenty Frydel, Marcin Steindor

U.S. Mine Ventilation Symposium

The stand is used to determine characteristics of fans and dust collectors, especially their efficiency at different levels of dustiness of the air being cleaned. Both wet- and dry-dust collectors arc manufactured as experimental installations, prototypes products designed for industrial applications. The design of the research installation has been so elaborated that the installation is characterized by great flexibility in respect of its applicability, enabling both comparison tests and attestation tests to be carried out. The accepted programme of the basic research covers testing of dust collectors of vortex type equipped with rotors featuring axial, diagonal and radial flow as …

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The Influence Of Coal Physical And Mechanical Properties And Mining Energy Consumption Factor On Airborne Respirable Dust Level, Antoni Koziel, Malgorzata Malec, Ewa Wardas Jun 1999

The Influence Of Coal Physical And Mechanical Properties And Mining Energy Consumption Factor On Airborne Respirable Dust Level, Antoni Koziel, Malgorzata Malec, Ewa Wardas

U.S. Mine Ventilation Symposium

The fact that there are not any explicitly defined relationships describing the influence of physical and mechanical properties of coal and of energy consumption factor on dust level prompted Polish and American investigators to carry out a joint research project within the framework of the U.S.- Poland Maria Sklodowska-Curie Joint Fund II. The paper presents methods used to perform tests under laboratory conditions at the Pittsburgh Research Laboratory as well as under real conditions in the course of coal cutting in polish coal mines. Measuring systems and results of the tests are described. The analysis carried out has provided a …

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Considerations For Estimating Remote Operator Dust Exposure Using Fixed-Point Samples On Continuous Mining Sections, Jeffrey M. Listak, Gerrit V. R. Goodman, Robert A. Jankowski Jun 1999

Considerations For Estimating Remote Operator Dust Exposure Using Fixed-Point Samples On Continuous Mining Sections, Jeffrey M. Listak, Gerrit V. R. Goodman, Robert A. Jankowski

U.S. Mine Ventilation Symposium

Respirable dust studies were conducted at several underground coal mining operations to evaluate and compare the dust measurements of fixed-point machine-mounted samples on a continuous miner and personal samples of the remote miner operator. Fixed-point sampling was conducted at the right rear corner of the continuous miner which corresponded to the traditional location of the operator's cab. Although it has been documented that higher concentrations of dust are present at the machine-mounted position, this work sought to determined whether a relationship exists between the concentrations at the fixed-point position and the dust levels experienced at the remote operator position and …

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Niosh/Nci Study Of Exposure To Diesel Exhaust In Underground Mines — An Industry Perspective, Christopher J. Pritchard Jun 1999

Niosh/Nci Study Of Exposure To Diesel Exhaust In Underground Mines — An Industry Perspective, Christopher J. Pritchard

U.S. Mine Ventilation Symposium

In 1992, the National Institute For Occupational Safety and Health (NIOSH) initiated a study, funded by the National Cancer Institute (NCI), to evaluate the health effects, if any, involving underground miners exposure to diesel exhaust. An industry organization, the Methane Awareness Research Group (MARG) already in place to respond to gassy mine related issues, was redirected to work with diesel concerns. In 1995, NIOSH released a draft protocol and feasibility assessment, indicating its intent to initiate s study at 14 underground mines, some of which were operated by MARG members. After considerable debate on the study protocol, in-mine industrial hygiene …

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A Mathematical Model Of Heat Transfer In Partially Insulated Airways In Deep, Frozen Ground Placer Mines, Sukumar Bandopadhyay, Hanguang Wu, Michael G. Nelson Jun 1999

A Mathematical Model Of Heat Transfer In Partially Insulated Airways In Deep, Frozen Ground Placer Mines, Sukumar Bandopadhyay, Hanguang Wu, Michael G. Nelson

U.S. Mine Ventilation Symposium

Large seasonal variations in the temperature of the ventilating air in mines in the arctic cause changes in the original thermal field through heat and mass exchanges between the air and the surrounding medium. These thermal interactions have major influence on climatic quality as well as on the stability of the mine openings. Thawing of walls and roof in mine airways can be reduced by various types of thermal-insulation. Application of thermal-insulation prevents deep thawing of the rockmass surrounding an airway. In this case, the mechanism of heat transfer around a frozen, underground airway would be much different. A model …

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Rapid Evaluation Of Rock Thermal Parameters At The Lucky Friday Mine, Ian J. Duckworth Jun 1999

Rapid Evaluation Of Rock Thermal Parameters At The Lucky Friday Mine, Ian J. Duckworth

U.S. Mine Ventilation Symposium

In many hot mines a large portion of the total heat load is associated with the surrounding strata. In order to maintain acceptable underground environmental conditions, the mine heat load must be controlled by the ventilating airstream, and in certain cases by mechanical refrigeration. To compute existing, or future heat additions from the surrounding rock, certain parameters must be -determined. These parameters include the rock thermal conductivity, thermal diffusivity, and the geothermal gradient (with relation to a virgin rock datum). These rock thermal parameters are typically estimated from published literature, or evaluated by laboratory or in-situ measurements. Presented in the …

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Foreword, Jerry C. Tien Jun 1999

Foreword, Jerry C. Tien

U.S. Mine Ventilation Symposium

No abstract provided.

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Comparison Of Methane Concentrations At A Simulated Coal Mine Face During Bolting, Charles D. Taylor, Edward D. Thimons, Jeanne A. Zimmer Jun 1999

Comparison Of Methane Concentrations At A Simulated Coal Mine Face During Bolting, Charles D. Taylor, Edward D. Thimons, Jeanne A. Zimmer

U.S. Mine Ventilation Symposium

Strategies for monitoring methane levels during roof bolting in an extended cut entry were evaluated. Testing was conducted at the Pittsburgh Research Laboratory's methane test gallery. Operating conditions were varied and methane releases at the face and drill holes were simulated. Methane readings were taken at the face, and at locations outby the face. Results show that, when the major source of methane was at the drill holes, the highest methane readings were at locations on or 6.1 m (20 ft) inby the bolting machine. Methods for selecting better outby sampling locations, when the majority of the methane is released …

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Methods For Dust Removal In Roadway Sections, Walenty Frydel, Marcin Steindor, Robert A. Jankowski Jun 1999

Methods For Dust Removal In Roadway Sections, Walenty Frydel, Marcin Steindor, Robert A. Jankowski

U.S. Mine Ventilation Symposium

Systems for dust extraction in roadway workings subjected to suction or forced ventilation are a combination of dust collecting equipment and facilities designed for ventilating the working. Such a combination of suitable equipment provides safe and effective dust removal and ventilation of a roadway working as well as is determinant of proper cooperation of the equipment a system is composed of. The development of effective dust collectors of wet type which provide safe operation under conditions of great exposure to coal dust and methane explosion hazards as well as of vortex ventubes allowing methane accumulations under the roof to be …

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Personal Cooling In Hot Workings, Michael A. Tuck Jun 1999

Personal Cooling In Hot Workings, Michael A. Tuck

U.S. Mine Ventilation Symposium

The number of mines experiencing climatic difficulties worldwide is increasing. In a large number of cases these climatic difficulties are confined to working areas only or to specific locations within working areas. Thus the problem in these mines can be described as highly localised, due to a large extent not to high rock temperatures but due to machine heat loads and low airflow rates. Under such situations conventional means of controlling the climate can be inapplicable and/or uneconomic. One possible means of achieving the required level of climatic control, to ensure worker health and safety whilst achieving economic gains, is …

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