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Articles 10021 - 10050 of 13031

Full-Text Articles in Engineering

On Criteria Of Stability Of Fans Operating In Parallel, Jerzy Krawczyk Jun 1999

On Criteria Of Stability Of Fans Operating In Parallel, Jerzy Krawczyk

U.S. Mine Ventilation Symposium

Ventilation systems with fans operating in parallel may have multiple operating points. The submitted paper presents a method which enables to reduce the number of points which should be taken into consideration. The concepts of a fan system containing: the fan, inlet duct, regulation door subsystem and its total characteristics were introduced. The analysis of local stability of equilibrium points of the system of ordinary differential equations describing unsteady incompressible flow in a simplified network ventilated by 2 fans in parallel leads to formulation of a simple condition of stability. For fans operating in parallel this condition refers to the …

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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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Autocad Based Mine Ventilation Analysis, Ted Sartain, Don Scheck Jun 1999

Autocad Based Mine Ventilation Analysis, Ted Sartain, Don Scheck

U.S. Mine Ventilation Symposium

Mine Vent is a mine ventilation analysis system which runs inside AutoCAD and uses the Penn State and other ventilation simulators. Working from AutoCAD as-mined and projected mine maps, the user picks the node locations and connects them with branches that correspond to the airway paths. Where survey data is not available, the system uses formulas to compute resistances. The system prompts the user for necessary parameters but the branch lengths are automatically computed. Powerful editing features reduce the time to modify existing schematics and try alternative ventilation options. The system also includes a survey data reduction module which outputs …

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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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Optimization Of The Ventilation System At Kidd Mine Of Falcon Bridge Limited, Josef Sedlacek Jun 1999

Optimization Of The Ventilation System At Kidd Mine Of Falcon Bridge Limited, Josef Sedlacek

U.S. Mine Ventilation Symposium

Kidd Mine is the single largest producing base metal mine of Falconbridge Limited. Approximately 3 million tonnes of zinc-copper ore is produced annually. The present ventilation system, designed some 30 years ago, uses a multitude of intake and exhaust fans, in a series-parallel configuration, to move 925 m3/s (2,000,000 cfm) through the mine. The system, owing to the ever increasing depth of mining, has reached its limitation and has become cumbersome to maintain. It was recognized that with the mine progressing from the original depth of 855 m (2800 ft) to the current depth of 2070 m (6800 …

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Water Injection In Longwall Top-Coal Caving Face In China, Zhang Yong, Fu Gui Jun 1999

Water Injection In Longwall Top-Coal Caving Face In China, Zhang Yong, Fu Gui

U.S. Mine Ventilation Symposium

This paper discussed the means of improving dust control efficiency using water injection. At first, the authors point out that internal water has effect on dust control. The objective of water injection is to increase the amount of internal water. Secondly, by analyzing the development trend of crack in top-coal, proper water injection station and boleholes can be determined for dust control.

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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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Recovery Of Methane From The Abandoned Golden Eagle Mine Property, Kenton L. Hupp, Carol Bibler, Raymond C. Pilcher Jun 1999

Recovery Of Methane From The Abandoned Golden Eagle Mine Property, Kenton L. Hupp, Carol Bibler, Raymond C. Pilcher

U.S. Mine Ventilation Symposium

The abandoned Golden Eagle underground coal mine in Colorado contains gassy coals from which Stroud Oil Properties, Inc. (Stroud) has been recovering gas since 1996. The mine closed permanently in 1996, and during its operation drained methane from gob and ventilation boreholes. Stroud currently produces about 1.8 million cubic feet of near pipeline quality gas per day from six of these boreholes. Although the project has proven successful, gas recovery has been challenging because of low bottom hole pressure and variable borehole performance. Wellhead compressors are required to boost gas pressure for delivery to the main plant. Connecting additional boreholes …

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Methane Drainage At The Minerales Monclova Mines In The Sabinas Coal Basin, Coahuila, Mexico, Daniel J. Brunner, Jose Ruben Ponce Jun 1999

Methane Drainage At The Minerales Monclova Mines In The Sabinas Coal Basin, Coahuila, Mexico, Daniel J. Brunner, Jose Ruben Ponce

U.S. Mine Ventilation Symposium

Minerales Monclova S.A. De C.V. (MIMOSA) operates five underground longwall mines in the Gassy Los Olmos Coals of the Sabinas Basin in the state of Coahuila in Northern Mexico. Because of high in-situ gas contents and high cleat and natural fracture permeability, MIMOSA has had to incorporate a system of methane drainage in advance of mining in order to safely and cost effectively exploit their reserves. In the early 1990s Resource Enterprises (REI) conducted reservoir characterization tests, numerical simulations, and Coal Mine Methane (CMM) production tests at a nearby mine property in the same basin. Using this information REI approached …

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A Proposed New Method To Determine The Effectiveness Of In-Heading Methane Control, F. J. Van Zyl Jun 1999

A Proposed New Method To Determine The Effectiveness Of In-Heading Methane Control, F. J. Van Zyl

U.S. Mine Ventilation Symposium

Various methods have been derived to determine the effectiveness with which ventilation systems clears headings of methane in a bord-and-pillar sections. A problem with applying these methods in underground sections is that the either require the face-area air quantity to be measured, which is virtually impossible in South African collieries, or they were developed for test galleries, making it difficult to use in production sections. Taking this into consideration the methane safety index (MSI) method was developed. The method utilizes methane data recorded around an active continuous miner (CM) and an activity log of cm operations to quantitatively assess methane …

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Proposed Regulation On Diesel Particulate Matter In Underground Coal Mines, Thomas F. Tomb Jun 1999

Proposed Regulation On Diesel Particulate Matter In Underground Coal Mines, Thomas F. Tomb

U.S. Mine Ventilation Symposium

The Mine Safety and Health Administration published a proposed rule for underground coal mines that use diesel-powered equipment. The proposed rule, published April 9, 1998, would establish new health standards. These new standards would reduce the risks to miners of serious health hazards that are associated with exposure to high concentrations of diesel particulate matter (dpm). The proposed rule would require that mine operators install and maintain high efficiency filtration systems on the most polluting types of diesel-powered equipment. The rule would also require that miners be trained about the hazards of dpm exposure. This paper reviews the requirements of …

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Mine Fire Detection In The Presence Of Diesel Emissions, J. C. Edwards, R. A. Franks, G. F. Friel, C. P. Lazzara, J. J. Opferman Jun 1999

Mine Fire Detection In The Presence Of Diesel Emissions, J. C. Edwards, R. A. Franks, G. F. Friel, C. P. Lazzara, J. J. Opferman

U.S. Mine Ventilation Symposium

A series of four coal combustion experiments was conducted at the National Institute for Occupational Safety and Health's (NIOSH) Pittsburgh Research Laboratory (PRL) in the Safety Research Coal Mine (SRCM) to evaluate the response of fire sensors to a small 0.61 m square smoldering coal fire which transitions to flaming combustion in the presence of diesel emissions. An optical path smoke sensor alarmed earlier than a point type diffusion mode ionization smoke sensor, which alarmed prior to a co alert value of 5 PPM above ambient. The presence of steady state diesel emissions resulted in a decrease in the optical …

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Non-Destructive Field Measurements Of Rock Temperature And Heat Flow In A Hot Mine, Vilen P. Chernyak, Eduard N. Malashenko, Pierre Mousset-Jones Jun 1999

Non-Destructive Field Measurements Of Rock Temperature And Heat Flow In A Hot Mine, Vilen P. Chernyak, Eduard N. Malashenko, Pierre Mousset-Jones

U.S. Mine Ventilation Symposium

A number of thermophysical measurements were carried out at the Meikle mine in Nevada in order to obtain new data concerning heat flows and wall temperatures in a hot mine. This was necessary to verify known methods of heat flow calculation and compare experimental with theoretical results. The Meikle mine was chosen because it is operated in an area of high rock temperature caused by the hydrothermal nature of the deposit and the presence of water at 60°C. The airflow rates in some of the inactive areas and the predicted background rock temperature at the mine are similar to those …

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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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Committees, Multiple Members Jun 1999

Committees, Multiple Members

U.S. Mine Ventilation Symposium

No abstract provided.

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Published Proceedings Of The Previous Mine Ventilation Symposia, Multiple Authors Jun 1999

Published Proceedings Of The Previous Mine Ventilation Symposia, Multiple Authors

U.S. Mine Ventilation Symposium

No abstract provided.

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Ventilation System Design For A Thin-Seam Mining Panel, Darren Holman, Ian Loomis, Malcolm Mcpherson Jun 1999

Ventilation System Design For A Thin-Seam Mining Panel, Darren Holman, Ian Loomis, Malcolm Mcpherson

U.S. Mine Ventilation Symposium

The extraction of coal from thin-seams is an important component of the future of coal mining in the commonwealth of Virginia. For thin-seam mining systems to be successful they must be able to provide production comparable to the current production methods in thicker seams. This necessitates the extensive use of remote mining technology. Regardless of The level of automation of the remote systems, efficient ventilation remains of paramount importance. This paper investigates several thin-seam mine panel schemes and possible variations in the ventilation systems. The primary approach made, however, is one of a pair of parallel panels mined simultaneously. A …

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Mathematical Description Of Air Cooling Using A Mining Diaphragm Cooler Taking Into Consideration The Condensation Of Water Vapour, Waclaw Dziunyński, Stanislaw Nawrat, Bernard Nowak, Janusz Roszkowski Jun 1999

Mathematical Description Of Air Cooling Using A Mining Diaphragm Cooler Taking Into Consideration The Condensation Of Water Vapour, Waclaw Dziunyński, Stanislaw Nawrat, Bernard Nowak, Janusz Roszkowski

U.S. Mine Ventilation Symposium

Taking into consideration the possibility of condensation of water vapour contained in air which flows through a diaphragm cooler, a mathematical model of space-time changes in air temperature, humidity, and also in the temperature of the heat exchanger and the cooling water in the cooler in question was created. In the mathematical description of air-cooling using the above-mentioned cooler two zones was identified. The first concerns the dry cooling of air, while within the second, the process of outdropping of water contained in the cooled air. Each of these zones has been described by applying a system of three partial …

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Rapid Extinguishing Of Sponcom Fires In Underground Mines, Zygmunt Kajdasz, George Zieba Jun 1999

Rapid Extinguishing Of Sponcom Fires In Underground Mines, Zygmunt Kajdasz, George Zieba

U.S. Mine Ventilation Symposium

The main purpose presented in this paper is to present active and passive methods to fight a sponcom fire. The active method uses an inert gas generator called the GAG while the passive method is through the use of ventilation software. In most sponcom situations a combination of these two methods results in rapid extinguishing of the overheated areas. The presented software allows for accurate and "real time" analysis of the ventilation network. Application of the GAG has been proven on many occasions as an effective means of large volumes of mine atmosphere.

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Performance Of Distributed Bagged Stone Dust Barrier In Combating Coal-Dust Explosions, Jan J. L. Du Plessis, Pierre S. Vassard Jun 1999

Performance Of Distributed Bagged Stone Dust Barrier In Combating Coal-Dust Explosions, Jan J. L. Du Plessis, Pierre S. Vassard

U.S. Mine Ventilation Symposium

The Kloppersbos Research Facility of the CSIR's Division of Mining Technology has developed a new method of building stone dust barriers. The new barrier makes use of a previous concept of containing stone dust in a bag, but incorporates a new method of rupturing the bag. This was achieved by adapting the closing mechanism and by balancing the stone dust content with the void in the bag. The bagged barrier was extensively tested in the 200-m test gallery. During these tests, it became evident that these bags could be made to rupture and spread stone dust when subjected to smaller …

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Cfd Analysis Of Mine Fire Smoke Spread And Reverse Flow Conditions, J. C. Edwards, C. C. Hwang Jun 1999

Cfd Analysis Of Mine Fire Smoke Spread And Reverse Flow Conditions, J. C. Edwards, C. C. Hwang

U.S. Mine Ventilation Symposium

A Computational Fluid Dynamics (CFD) program was used to model buoyancy induced Product-Of-Combustion (POC) spread from experimental fires in the National Institute For Occupational Safety And Health (NIOSH), Pittsburgh Research Laboratory (PRL), safety research coal mine. In one application, the CFD program was used to predict spread from fires in an entry under zero airflow conditions. At a location, 0.41 m below the entry's roof at a distance of 30 m from the fire, the measured smoke spread rates were 0.093 and 0.23 m/s for a 30 and a 296 kw fire, respectively. The CFD program predicted spread rates of …

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Recovery Of Minerales Monclova Minas V, Patrick Graham, William Marston, Donald Mitchell, John W. Stevenson, David Sullivan Jun 1999

Recovery Of Minerales Monclova Minas V, Patrick Graham, William Marston, Donald Mitchell, John W. Stevenson, David Sullivan

U.S. Mine Ventilation Symposium

Methane issuing from a roof-bolt hole ignited when the hot bit was withdrawn. Similar ignitions have occurred in other mines. This one differed in that flames spread quickly, coal was ignited, and, after three futile hours of applying inadequate water and extinguishing agents, the mine was sealed. Fires are fuel and ventilation controlled. In this mine there was an abundance of methane, coal, and wood lagging. Recovery of the mine, therefore, depended on successful control of its ventilation. The recovery was done without anyone suffering a scratch; a remarkable feat considering the abnormal methane outflows and concentrations, the continuing evidence …

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Gob Spontaneous Combustion In A Fully Mechanized Long-Wall Top-Coal Caving Face, Jingcai Xu, Jun Deng, Xinghai Zhang, Xingming Guo, Fu Wen Jun 1999

Gob Spontaneous Combustion In A Fully Mechanized Long-Wall Top-Coal Caving Face, Jingcai Xu, Jun Deng, Xinghai Zhang, Xingming Guo, Fu Wen

U.S. Mine Ventilation Symposium

Geological conditions allow, underground coal mines in China tend to use comprehensively mechanized roof-coal caving technique in an effort to gain a higher degree of mechanization at coal faces as well as higher coal production rates. As a face advances, a large amount of coal will be left behind in its gob area which may experience a self-enhancing process of coal oxidation and heat accumulation, ultimately leading to open fire. Such a self-enhancing coal spontaneous combustion process is a significantly impeding mine safety and productivity. A sound mathematical model is an important step to predict the probability of spontaneous combustion …

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Installation Of Two Main Fans At P.T. Freeport Indonesia's Underground Facilities, Felipe Calizaya, A. Mulyadi Jun 1999

Installation Of Two Main Fans At P.T. Freeport Indonesia's Underground Facilities, Felipe Calizaya, A. Mulyadi

U.S. Mine Ventilation Symposium

This study summarizes the technical aspects related to the installation of two main fans at P.T. Freeport Indonesia: one centrifugal and one axial. The fans were installed to increase the exhaust capacity of two vent systems. The 450 kW fan has been installed on surface to support an underground mine expansion project. The installation included the construction of a transition chamber, a retention wall, and the fan installation and commissioning. The 250 kW fan has been installed in an incline to increase the exhaust capacity of an ore pass ventilation system. The study presents the installation details from ground excavation …

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Theoretical Analysis Of Jet Fan Performance Using Momentum And Energy Considerations, Kuda R. Mutama, Allan E. Hall Jun 1999

Theoretical Analysis Of Jet Fan Performance Using Momentum And Energy Considerations, Kuda R. Mutama, Allan E. Hall

U.S. Mine Ventilation Symposium

Jet fans or ductless fans have been analyzed using momentum and energy considerations. This analysis is necessary for the mechanisms of mixing between the jet primary flow and the secondary or induced stream to be understood. In each case it is possible to predict performance in terms of pressure, flow ratios and hence the percentage mechanical efficiency of the whole system using equations derived from momentum and energy principles. The analysis given is suitable for situations where jet fans are utilized as area boosters in a mine ventilation system and in longitudinal vehicular tunnel ventilation. The energy and momentum equations …

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Axial Flow Fan Use At San Manuel Mine, Kuda R. Mutama, Dave P. Pelletier Jun 1999

Axial Flow Fan Use At San Manuel Mine, Kuda R. Mutama, Dave P. Pelletier

U.S. Mine Ventilation Symposium

A case study is presented for the use of multiple axial flow main fans as the principle source of the primary mine ventilation system for a large multi level mine. Formerly owned by Magma Copper, BHP Copper Inc.'s San Manuel Mine is a large underground block caving copper mine which started producing copper in 1955. The San Manuel Mine produces over 50,000 tons per day sulfide copper ore. The total airflow into this mine is approximately 800 m3/s (1,600,000 cfm). Providing adequate ventilation has been a very challenging experience as new, deeper levels are developed. BHP relies on …

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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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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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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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Optimization Of Main Exhaust Fan Systems At Battle Mountain Canada Ltd., Golden Giant Mine, László Götz, Euler De Souza Jun 1999

Optimization Of Main Exhaust Fan Systems At Battle Mountain Canada Ltd., Golden Giant Mine, László Götz, Euler De Souza

U.S. Mine Ventilation Symposium

In 1997, production needs required that the exhaust conditions at the Golden Giant Mine be maximized. One of the principal exhaust raises, the West Return Air Raise #1, designed to handle some 189 m3/s (400,000 cfm) but operating at 102 m3/s (216,000 cfm), was a primary candidate for optimization. This paper describes the major design changes and installation modifications carried out at this surface fan installation. The new installation not only outperformed the design expectations but also achieved the new mine exhaust requirements.

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