Research And Application Of Blast Furnace Pulverized Coal Mass Flow Detection System With Dielectric Constant Been Compensated

Gas-solid two phase flow is widely used in the pneumatic conveying process of the blast furnace coal powder injection process.Capacitive method is the main phase concentration measurement method of gas-solid two phase flow.The invariance of the solid phase's permittivity is deemed to be the premise of present capacitive phase concentration measurement method.However,measurement errors of solid phase's concentration would be caused while the solid phase's permittivity changes.In consideration of the characteristics of the 2#blast furnace coal injection about large coal injection duct diameter,frequently changes of the coal ratio,long pulverized coal conveying distance,a new measurement system of coal mass flow which can compensate the variation of the solid phase's permittivity based on compound sensor and Soft-Sensing Technique was proposed,The main work of this thesis is showed as follows,(1)The regulation ways of mass flow is analyzed in GuangXi LiuZhou Iron&Steel.Determine the measurement solution based on the actual situation of the 2#blast furnace coal injection;(2)Present phase concentration measurement method of gas-solid two phase flow was studied and analyzed by reading related literature;the compensating method of the variation of the solid phase's permittivity was studied;a new phase concentration measurement method which can compensate the variation of the solid phase's permittivity was proposed;(3)Capacitance sensors with parallel surface plates,spiral plates,and other structures were analyzed in ANSYS;the experiment on temperature characteristics were made based on the situation of the laboratory.Finally,the structures and sizes of capacitance sensor combinations with best compensating results were obtained;(4)Fulfill the dedign of density and speed measure circuit,realize the capacitance signal filtering,amplification and the signal processing;(5)Fulfill the design of digital circuit system.The core control chip of the circuit is LPC4330,with the A/D conversion chip ADS8688,the internet communication circuit and the off-chip memory circuit.Fulfill the program design of the lower position machine syste.Finally,fulfill the measurement and communication;(6)In consideration of the situation of industry environment,the speed measurement arithmetic were complied by the compersion of the cross correlation arithmetic and the waveform comparison.Besides that,model parameters online-update is also complicated;(7)In order to complicate the actual demand,the software is encoded in the exploitation environment of Visual Studio 2012.The system mainly include communication module,Microsoft SQL management system,On-line mass-flow correction module and user Interface,reporting system?...