Study On Jet Pump Under Cavitation Condition Used In Foam Dust Control Technology

Mine dust is one of the main disasters in coal mine. At present, the dust concentration of the coal mine tunneling face is high. To solve the problem, the foam dust control technology is applied. The foam can cover the dust source area, realizing the highly effective dust suppression effect. But restricted by the coal mine tunneling environment, the reliability of the foam dust control system needs to be strengthened, especially the foam agent adding process is influenced by pressure fluctuation. In this paper, Basing on the jet pump cavitation principle, the new jet adding device is designed. It can improve the reliability of the foam system, and it has been successfully applied to the tunneling working face.Based on the cavitation characteristics of jet pump, this paper analysis the liquid absorption principle, studies the basic equation for single nozzle and multi nozzle jet device, and provides theoretical basis for the design of the jet devices.Using CFD numerical simulation software, the paper analyzes absorption process of the multi nozzle jet device, it concluded that with the increase of number of nozzle, the extent of cavitation reduces gradually; The single nozzle jet device suction process is analyzed, it concluded that gas-liquid interface oscillation characteristics over time in the fluid absorption process.Laboratory experiment is carried out on the performance of jet device, it is concluded that low pressure ratio, the absorption process stable, high pressure ratio, the absorption process stable fluctuations. The pressure ratio is 0-0.25, the absorption volume is 3.2 L/h, when the pressure ratio is in the range of 0.25-0.73, the absorption volume volatility.On-site application of foam dust technology is applied. All dust and respirable dust concentration in the space respectively is 42 mg/m3 and 10 mg/m3, the dust removing efficiency reached 92.7% and 92.4%.