Experimental Research and Numerical Simulation of Ejector Precipitator in a Fully Mechanized Mining Face

Abstract

In order to effectively reduce the coal dust concentration in a fully mechanized mining face, this research used laboratory experiment, numerical simulation, and field test to conduct an in-depth exploration of the ejector precipitator installed at the low-level caving coal hydraulic support. Firstly, through the experimental platform in the laboratory, the dust removal effect of the nozzle with different structural parameters was tested, and the 3D particle dynamic analyzer was adopted to verify its atomization characteristics; then, the structural parameters corresponding to the nozzle in the best test results were obtained. Secondly, by using Fluent, the negative pressure flow field in the ejector barrel was numerically simulated. The results indicated that when the pressure of supply water was 12 MPa, the negative pressure value formed in the flow field was the lowest and the inspiratory velocity was the largest, which was conducive to dust removal. Finally, the tests of liquid–gas ratio and dust removal ratio were carried out in a fully mechanized mining face. The results showed that when the nozzle specification recommended by the experiment and the pressure of supply water recommended by the numerical simulation were used, the removal ratios of the total coal dust and the respirable coal dust were 89.5% and 91.0%, respectively, at the measuring point of the highest coal dust concentration. It indicates that the ejector precipitator has a good application effect in reducing the coal dust concentration in a fully mechanized mining face and improving the work environment of coal mine workers.

Researches on the numerical simulation of the dust pollution characteristics and the optimal dust suppression wind-speed on fully mechanised caving face

“…Recent studies on the wind flow in coal mines and the distribution law of dust transport serve as the reference for the selection of dust prevention measures and the design of dust prevention equipment on the working face through analysing the escape law of wind flow and dust on the working face and their relationship. Zhai et al (2020) studied the multi-nozzle injector duster on hydraulic support by combining numerical simulation with a field test When the water supply pressure is 12 MPa, the negative pressure formed by the flow field of the multi-nozzle injector duster is the lowest and the suction speed is the largest, which is conducive to dust removal. Finally, the field test of this device on a fully mechanised coal face shows that the removal rates of total coal dust and inhalable coal dust are 89.5% and 91.0%, respectively.…”