Research And Application Of On-line Detection Technique Of Pulverized Coal Pneumatic Conveying Flow Parameters

Pneumatic powder delivery technology has been widely used in metallurgy,electric power and other industries.Among them,the mass flow,velocity and other flow parameters reflect the flow of gas-solid two-phase flow of the important parameters of the industrial production process,which is essential especially for the production process automation and energy conservation.The thesis selected National Natural Science Foundation of China's major project "Large Blast Furnace Two Paste Process Running Information of High Performance Testing Methods"for the research background to Liuzhou Iron and Steel 2#blast furnace pulverized coal injection system for the study.Considering coal conveying system of coal conveying pipe length is long,the size of the main coal conveying and frequent changes in the type of coal.Thesis design coal mass flow detection system with dielectric constant compensation.The dissertation mainly carries out the following work:(1)The method of measuring the volume concentration of solid phase is studied,and a method for measuring the volume concentration of solid phase is proposed.The direct interface technology is improved in the initial,end and process of the discharge.For the next solid phase volume concentration measurement research has been explored.(2)Aiming at the frequent change of coal in industrial site,a compensation method of dielectric constant change of solid medium is adopted.Based on this compensation method,a new type of gas-solid two-phase flow capacitance concentration measurement system is established.(3)According to the demand of system measurement,the compensation concentration measurement circuit and the coal injection manifold concentration and speed measurement circuit are designed.The AD conversion,Ethernet communication circuit and the external memory circuit are designed with LPC2388 chip as the core.Measurement and communication;based on Visual C++ programming PC software,mainly to achieve traffic model calculation,communication,database management and human-computer interface.(4)On-site installation and commissioning of the flow meter and the coal dielectric constant compensation device to achieve coal inj ection manifold and compensation sensors and host computer data acquisition and data communications.(5)A pulverized coal mass flow measurement model has been established,and the on-line calibration of pulverized coal mass flow measurement model is realized.(6)Pulverized coal mass flow detection system based on text design is used to test the performance of pulverized coal mass flow detection in Liuzhou Iron and Steel 2#BF for 24 hours.Compared with the total amount of coal injected for one hour by electronic scale,the cumulative flow deviation of the instantaneous flow rate of 10s is less than 5%.