Research On Measurement Methods For Solids Flux In Riser

Solids flux is a vital operation parameter of the gas-solid flow in riser.In the current experiment research,the volumetric method is widely used to measure the solids flux in riser.But there exists some problems with the volumetric method.The whole measurement process of this method is quite complicated and has large measurement intensity.Moreover,the volumetric method has a low measurement accuracy and reliability.So in a cold model riser experiment apparatus,HDLDG-06 solids flowmeter and PV-6D optical fiber system are separately systematically studied and applied in riser in different operating gas velocity and solids flux.The research results of the HDLDG-06 solids flowmeter show that the operating gas velocity and solids flux both play a vital part in the measurement results of the solids flowmeter.In the experiment operating range,when the operating gas velocities in riser are lower than 18 m/s,there exists a critical solids flux.When the solids flux of the measured section is lower than the critical value,the solids flowmeter has quite satisfying measurement results.While the solids flux of the measured section is higher than the critical value,the solids flowmeter has quite bad measurement results.What's more,the critical solids flux increases with the operating gas velocities.When the operating gas velocities are higher than 18 m/s,the solids flux in riser doesn't reach the critical value and the solids flowmeter has good measurement results in the solids flux range of this experiment.Furthermore,the cross-sectional average particle concentration in riser has a direct influence on the measurement results of the solids flowmeter and there exists the same critical value of the cross-sectional average particle concentration(about 6.9 kg/m3).When the cross-sectional average particle concentration in riser is lower than the critical value,the solids flowmeter has good measurement results.While the cross-sectional average particle concentration in riser is higher than the critical value,the solids flowmeter has unsatisfying measurement results.Based on the conclusion above,the correction relation and its applied range are both given for the solids flowmeter to measure the solids flux in riser.A method to enlarge the range of solids flowmeter application is put forward.At the same time,an improvement measurement for the solids flowmeter are proposed,combining the Faraday's law of electromagnetic induction and electrostatic measurements.The improved solids flowmeter can be used to measure the cross-sectional average particle velocity,cross-sectional average particle concentration and solids flux at the same time.In the experiment of PV-6D optical fiber system,there exists a problem that the solids flux and particle velocity both have quite a large deviation calculated by the current method,basing on the moving valid time of the particle.So a new method for calculating the solids flux and particle velocity in riser is proposed,basing on all the sampling time.Contrary to the current method,there has an obvious improvement of the solids flux and particle velocity deviation calculated by this paper.At the same time,two correction relations to measure the solids flux in riser by the optical fiber system are separately given according to the particle concentration and particle velocity measured by optical fiber or particle concentration voltage obtained by optical fiber and operating gas velocity in riser.