Method and device for measuring particle size distribution of discrete-state particles

Abstract

The invention discloses a method and device for measuring particle size distribution of discrete-state particles. The method comprises the following steps of: firstly, arranging a sound field of a departure plane standing-wave sound wave or a traveling plane wave; generating transverse vibration by a discrete-state particle system under the action of sound wave, photographing transverse motion trails of the particle system continuously, and recording images sequentially; calculating an amplitude value x of a particle in the sound field within the time t, obtaining an actual vibration curve of the particle, comparing the actual vibration curve with a vibration curve of the particles with different particle diameters in the sound field under the condition of theoretical calculation, taking the particle diameter with the highest curve approximation degree as the particle diameter of the particle until the particle diameters of all the particles in the particle system are determined completely, and obtaining the particle size distribution of the particle system. According to the method disclosed by the invention, a particle size measurement lower limit which is lower than that obtained by the adoption of an optical image method can be obtained, complete non-contact measurement is realized, the measuring accuracy and the automation degree are high, and fast and accurate measurement can be carried out.

Description

technical field [0001] The invention relates to particle size measurement technology, in particular to a method and device for measuring particle size distribution in a discrete state. Background technique [0002] The measurement of particle size and concentration of dispersed particles has a wide application background in the fields of power, chemical industry, medicine, environmental protection, water conservancy, materials and other fields involving two-phase flow. The existing measurement methods include sieving method, microscope method, holographic method, electric induction method, sedimentation method, etc. The basic principle is to obtain the particle size and shape of the particle by imaging and converting the magnification based on the optical image of the particle feature. [0003] Traditional measurement methods have the following defects: [0004] 1. When measuring by the sieving method, the measuring device needs to be in direct contact with the sample to b...

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Problems solved by technology

However, when it is used for particle measurement, especially the measurement of suspended particles in the medium, the measurement requirements are relatively high, and the holographic interferometry is relatively complicated from the device to the image processing process; the measurement of the microscope and optical image method requires direct observation of the complete particle morphology , so the requirements for the microscopic magnification of the measuring instrument are high. When the particle size of the discrete particles is small, it is difficult to observe directly. Although the theoretical observation limit of the optical microscope can reach 0.5 microns, in practice, when the particle size is 1 micron Below, the optical microscope is basically unable to directly observe

[0006] 3. In addition, when using optical microscopy and holography to measure, although it is not necessary to observe with the naked eye, direct imaging of particles requires obtaining morphology characteristics, which requires relatively high imaging requirements. Therefore, when used for dynamic measurement of particles, accurate Observation is more difficult, the probability of misjudgment is higher, and better measurement results are often not obtained

[0007] 4. The existing various observation methods require a lot of manual operation in the observation, and the degree of automation is low

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