Planetary wheel rolling on a coal-bed was simplified as rigid wheel rolling on the coal-bed with a rigid base when a Ver- tical planetary mill(VPM)is running.Based on our analysis,we conclude that the Bekker formulati...Planetary wheel rolling on a coal-bed was simplified as rigid wheel rolling on the coal-bed with a rigid base when a Ver- tical planetary mill(VPM)is running.Based on our analysis,we conclude that the Bekker formulation for computing rolling resis- tance is not applicable to calculate directly the rolling resistance of the wheel.According to the principle of the Bekker apparatus,pressure-sinkage curves were obtained by tests on a piece of mono-axial consolidation apparatus used in soil-mechanics.The de- formation modulus of the coal-bed was calculated using elastic mechanics.A finite element model of the planetary wheel coal-bed was built up by the use of a rigid and a Drucker-Prager material model in LS-DYNA.According to the simulation results,the wheel rolling resistance,the grinding power consumption and the motor power of the mill were calculated and the mistake in the initial design of the mill was modified.The simulation results agree well with the results of the semi-industrial tests.展开更多
Minimum fluidization velocity of quartz sand and glass bead under different pressures of 0.5, 1.0, 1.5 and 2.0 MPa were investigated. The minimum fluidization velocity decreases with the increasing of pressure. The in...Minimum fluidization velocity of quartz sand and glass bead under different pressures of 0.5, 1.0, 1.5 and 2.0 MPa were investigated. The minimum fluidization velocity decreases with the increasing of pressure. The influence of pressure to the minimum fluidization velocities is stronger for larger particles than for smaller ones. Based on the test results and Ergun equation, an experience equation of minimum fluidization velocity is proposed and the calculation results are comparable to other researchers＇ results.展开更多
文摘Planetary wheel rolling on a coal-bed was simplified as rigid wheel rolling on the coal-bed with a rigid base when a Ver- tical planetary mill(VPM)is running.Based on our analysis,we conclude that the Bekker formulation for computing rolling resis- tance is not applicable to calculate directly the rolling resistance of the wheel.According to the principle of the Bekker apparatus,pressure-sinkage curves were obtained by tests on a piece of mono-axial consolidation apparatus used in soil-mechanics.The de- formation modulus of the coal-bed was calculated using elastic mechanics.A finite element model of the planetary wheel coal-bed was built up by the use of a rigid and a Drucker-Prager material model in LS-DYNA.According to the simulation results,the wheel rolling resistance,the grinding power consumption and the motor power of the mill were calculated and the mistake in the initial design of the mill was modified.The simulation results agree well with the results of the semi-industrial tests.
文摘Minimum fluidization velocity of quartz sand and glass bead under different pressures of 0.5, 1.0, 1.5 and 2.0 MPa were investigated. The minimum fluidization velocity decreases with the increasing of pressure. The influence of pressure to the minimum fluidization velocities is stronger for larger particles than for smaller ones. Based on the test results and Ergun equation, an experience equation of minimum fluidization velocity is proposed and the calculation results are comparable to other researchers＇ results.
