Multi-sensor integration including electrostatic sensor

pressure sensor and capacitance tomography system(ECT)were used to investigate the flow behavior of dense phase pneumatic conveying of coal powder under various operating conditions(transportation pressure difference

carrier gas and moisture content).Statistics and fractal method were applied to extracting the Hurst of electrostatic fluctuation signal and the variance of differential pressure signal.Experimental results showed that when CO2 was used as carrier gas

the complexity of micro-movement of individual particle increased with increasing total transportation pressure difference and the interaction between gas and particles was more intensified under pressure difference of 0.75 MPa.However

the macro-motion state of the coal particles kept stable.The increase of coal moisture content resulted in higher complexity of micro-motion of individual particle

and yet had no influence on the stability of macro-motion state of the whole coal particles.When N2 was used as carrier gas

coal average concentration over the cross section of the pipeline fluctuated obviously and the macro-motion state of the whole coal particles was unstable.But the micro- motion of individual coal particle was similar to that with carrier gas of CO2.