An online measurement method of frequency-sweeping ultrasonic focused sediment particle size distribution

Abstract

The invention discloses an on-line measurement method for frequency-sweeping ultrasonic focusing type sediment particle size distribution. The present invention builds a set of measuring devices with a focused ultrasonic probe as the core, and at the same time uses the screening method and microscope method to configure sediment samples of different particle sizes; debugs the measuring system, and starts the measuring device after it is accurate; changes the ultrasonic wave Frequency, a series of experiments with sediment particle size as a variable were carried out at different ultrasonic frequencies to obtain the data of the received waveform; phase space segmentation and symbol dynamic filtering based on the Hilbert transform were performed on the collected signals to obtain the same Measurement of parameter values ​​related to particle size; data fitting is performed on the scatter diagrams of measurement and sediment particle size at different frequencies to obtain a sediment particle size measurement model. The invention can effectively reduce the scattering attenuation in the propagation process, increase the acceptable sound energy at the receiving transducer, improve the signal-to-noise ratio, and the sensitivity and measurement accuracy of the entire measurement system.

Description

technical field

[0001] The invention relates to the fields of ultrasonic liquid-solid two-phase flow measurement, signal processing, sediment particle size technology, and pattern recognition, in particular to a frequency-sweeping ultrasonic focused online measurement method for sediment particle size distribution. Background technique

[0002] The problem of sediment particles in natural water bodies is related to water conservancy machinery, riparian agriculture, sea and land resources, and ecological environment. Accurate particle size measurement in liquids is critical in many areas of industrial production, including medical pharmaceuticals, energy transportation, and more.

[0003] The traditional methods for measuring the particle size of suspended substances include weighing method, particle size meter method, pipette method, sieving method, extinction method and centrifugation method. The currently widely used particle measuring methods are: sieving method, microsc...

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