Development and experimental study of a scaled model for dust dispersion in fully-mechanized mining face

Abstract

Model experiment is one of the research methods for the fundamental theory of coal mine dust control. To address the current deficiencies in experiment development for research on dust migration rules, a scaled model for dust dispersion in a fully-mechanized mining face was constructed based on the design prototype of the 25211 mining face at the Hongliulin mine, using a similar theory. The model includes a mining face, a return airway, a haulage roadway, and a subsidiary roadway constructed using aluminum alloy profiles and tempered glass. The model uses U-shaped exhaust ventilation. The shearer, hydraulic support, and reverse loader are equipped with dust sources, and each dust source operates independently with distinct dust generation processes that do not interfere with each other. An experimental plan for dust diffusion during shearer dust generation was designed with a wind speed of 1.0 m/s. Preliminary model experiment was conducted based on this model. The results showed that the farther away from the dust source, the lower the dust concentration. The relative mass distribution and cumulative mass distribution of falling dust particles also showed that the farther away from the dust source, the smaller the particle size of the falling dust particles. The maximum size distribution decreased from 51.4 μm to 27.9 μm, and the average particle size decreased from 34.9 μm to 20.6 μm. The test model results were validated by field tests, indicating that the constructed model has good reliability. Finally, the critical areas for future research based on this model were proposed. The development of the model provides valuable experimental support for the theory of multi-source dust transportation in the airflow on the fully-mechanized mining face.