Measurement Of The Solid Phase Concentration By Acoustic Method

The measurement technology of Gas-solid two phases flow has been widely used in practical industrial processes, such as power plants, iron and steel factories, chemical and food industries. And the accurate measurement and real-tine monitoring of Gas-solid two phases flow is directly related to product quality, security and stability of industrial processes or energy supply balance. However, two phases flow measurement is an urgent technical problem waiting to be solved, owing to the complex flowing characteristics of Gas-solid two phases flow.Basing on the extensive research and comparison of some Gas-solid two phases flow measurement techniques, research have been focused on the principle of Piezoelectric ceramics sensor, weak signal detection, the design of Piezoelectric ceramics sensor data acquisition system and its application in the parameter measurement of Gas-solid two phases flow or other aspects.The following statement is the main work completed in this paper:1. With a full investigation and research done on the relevant background of Gas-solid two phases mass flow measurement, the concentration measurement of Gas-solid two phases flow is chosen as study point.2. Piezoelectric ceramics sensor and electret microphone have been deeply studied and designed. Comparing their advantages and disadvantages by some experiments, the paper select piezoelectric ceramics sensor as the sensor of the measurement system.3. Design a filter amplifier circuit, apply filtering, shielding, grounding and other EMC technologies to improve signal SNR Ratio.4. ARM processor is applied in the data acquisition system to realize the data acquisition, and send sampling data to the PC.5. FIR filtering, mean square error calculation of the sampled data are done in the PC and select random signal analysis method of statistical analysis to process the sampled data.6. Doing a large number of experiments on the base of algorithms and analysis methods, it can accurately identify the changes of sand concentration, determine the starting time of sand, obtain the qualitative relationship between mean square error value and sand concentration and realize on-line display of the relevant flowing parameters of sand.