A three-dimensional mathematical model,based on differential balances of mass and momentum,hasbeen developed to describe the two-phase flow of gas and liquid through the dropping zone of the blast fur-nace.Agreement b...A three-dimensional mathematical model,based on differential balances of mass and momentum,hasbeen developed to describe the two-phase flow of gas and liquid through the dropping zone of the blast fur-nace.Agreement between observed and calculated values verifies the validity of this model.On the basis of this model,various parameters for the surrounding of the dry zone of Blast FurnaceNo.I-BF of the Beijing Iron and Steel Company have been computed,from which a diagram for demar-cation of fluidization of coke and flooding of slag has been proposed.展开更多
A critical challenge of any blast simulation facility is in producing the widest possible pressure-impulse range for matching against equivalent high-explosive events.Shock tubes and blast simulators are often constra...A critical challenge of any blast simulation facility is in producing the widest possible pressure-impulse range for matching against equivalent high-explosive events.Shock tubes and blast simulators are often constrained with the lack of effective ways to control blast wave profiles and as a result have a limited performance range.Some wave shaping techniques employed in some facilities are reviewed but often necessitate extensive geometric modifications,inadvertently cause flow anomalies,and/or are only applicable under very specific configurations.This paper investigates controlled venting as an expedient way for waveforms to be tuned without requiring extensive modifications to the driver or existing geometry and could be widely applied by existing and future blast simulation and shock tube facilities.The use of controlled venting is demonstrated experimentally using the Advanced Blast Simulator(shock tube)at the Australian National Facility of Physical Blast Simulation and via numerical flow simulations with Computational Fluid Dynamics.Controlled venting is determined as an effective method for mitigating the impact of re-reflected waves within the blast simulator.This control method also allows for the adjustment of parameters such as tuning the peak overpressure,the positive phase duration,and modifying the magnitude of the negative phase and the secondary shock of the blast waves.This paper is concluded with an illustration of the potential expanded performance range of the Australian blast simulation facility when controlled venting for blast waveform tailoring as presented in this paper is applied.展开更多
Coal is the mainstay of power generation in India. The manifold increase in demand for coal puts a huge pressure on augmenting production, primarily from opencast mines. The increase in production necessitates heavy b...Coal is the mainstay of power generation in India. The manifold increase in demand for coal puts a huge pressure on augmenting production, primarily from opencast mines. The increase in production necessitates heavy blasting in overburden and coal benches of opencast mines which poses numerous challenges in carrying out blasting operation techno-economically. Presently, the consumption of industrial explosives and accessories in Coal India has touched a whopping figure of 350 million USD per annum. The present paper discusses some of key challenges faced in various mines of coal in India during blasting where blast instrumentation may contribute to the mine productivity and economics significantly. Blast Instrumentation at mine level will prove to a harbinger for practicing blasting engineers. The blast instrumentation at Sonepur Bazari project resulted in direct savings in explosives cost by 29.5% The use of well characterized explosives obtained by using MASW （multi channel analysis of surface waves） technique at Umrer project of Coal India Limited resulted in improvement in fragment size by 12.76%. It may be concluded with high degree of confidence that blast instrumentation at mine level will influence the mine productivity and economics.展开更多
文摘A three-dimensional mathematical model,based on differential balances of mass and momentum,hasbeen developed to describe the two-phase flow of gas and liquid through the dropping zone of the blast fur-nace.Agreement between observed and calculated values verifies the validity of this model.On the basis of this model,various parameters for the surrounding of the dry zone of Blast FurnaceNo.I-BF of the Beijing Iron and Steel Company have been computed,from which a diagram for demar-cation of fluidization of coke and flooding of slag has been proposed.
基金funded partially by the Australian Government through the Australian Research Council’s Linkage Infrastructure,Equipment and Facilities (LIEF)funding scheme (LE130100133)。
文摘A critical challenge of any blast simulation facility is in producing the widest possible pressure-impulse range for matching against equivalent high-explosive events.Shock tubes and blast simulators are often constrained with the lack of effective ways to control blast wave profiles and as a result have a limited performance range.Some wave shaping techniques employed in some facilities are reviewed but often necessitate extensive geometric modifications,inadvertently cause flow anomalies,and/or are only applicable under very specific configurations.This paper investigates controlled venting as an expedient way for waveforms to be tuned without requiring extensive modifications to the driver or existing geometry and could be widely applied by existing and future blast simulation and shock tube facilities.The use of controlled venting is demonstrated experimentally using the Advanced Blast Simulator(shock tube)at the Australian National Facility of Physical Blast Simulation and via numerical flow simulations with Computational Fluid Dynamics.Controlled venting is determined as an effective method for mitigating the impact of re-reflected waves within the blast simulator.This control method also allows for the adjustment of parameters such as tuning the peak overpressure,the positive phase duration,and modifying the magnitude of the negative phase and the secondary shock of the blast waves.This paper is concluded with an illustration of the potential expanded performance range of the Australian blast simulation facility when controlled venting for blast waveform tailoring as presented in this paper is applied.
文摘Coal is the mainstay of power generation in India. The manifold increase in demand for coal puts a huge pressure on augmenting production, primarily from opencast mines. The increase in production necessitates heavy blasting in overburden and coal benches of opencast mines which poses numerous challenges in carrying out blasting operation techno-economically. Presently, the consumption of industrial explosives and accessories in Coal India has touched a whopping figure of 350 million USD per annum. The present paper discusses some of key challenges faced in various mines of coal in India during blasting where blast instrumentation may contribute to the mine productivity and economics significantly. Blast Instrumentation at mine level will prove to a harbinger for practicing blasting engineers. The blast instrumentation at Sonepur Bazari project resulted in direct savings in explosives cost by 29.5% The use of well characterized explosives obtained by using MASW （multi channel analysis of surface waves） technique at Umrer project of Coal India Limited resulted in improvement in fragment size by 12.76%. It may be concluded with high degree of confidence that blast instrumentation at mine level will influence the mine productivity and economics.
