Experimental investigations of a new surfactant adding device used for mine dust control

To guarantee the stable and quantitative adding of surfactant into the pressure pipe and not be affected by the inlet and outlet pressure changing, the method utilizing jet pump cavitation characteristics to add surfactant was proposed. Keeping pressure ratio lower than the critical pressure ratio, the adding quantity could remain unchanged. In order to improve the stabilities, reduce the pressure loss and improve the critical pressure ratio of the jet cavitation adding method, a new two-stage cavitation jet adding method and device were proposed, and the performance was investigated experimentally under different working flows and outlet pressures, and compared to the cavitation jet pump in this paper. The results showed that the negative pressure remained unchanged within a certain range of outlet pressure, then decreased gradually with the increase of outlet pressure for the new device, which was similar with the traditional one. Furthermore, the critical pressure ratio of the new device was larger than the traditional one, which indicated that the pressure loss for the new device was smaller and it was more stable as the adding amount of surfactant was constant. In addition, the critical pressure ratio could increase by reducing the additive proportion of surfactant. Based on the above contributions and field investigation, it is believed that the study will play an important role for automatic quantitative control. (C) 2018 Elsevier B.V. All rights reserved.