Effects of Geometric Parameters on Air Suction Characteristics of a New Jet-Type Foam Generator for Mine Dust Suppression

Abstract

This paper proposes a novel jet-type foam generator of air self-suction intended for dust control in coal mines that overcome the shortcomings of conventional compressed air foam preparation devices. Three non-dimensional numbers of geometric parameters were obtained through theoretical analysis, namely distance–diameter ratio ( $$R_\mathrm{td})$$ , length–diameter ratio ( $$R_\mathrm{ld})$$ , and area ratio ( $$R_{\mathrm{m}})$$ . And various experiments were conducted to investigate the effects of the three important non-dimensional geometric parameters on air suction properties of the proposed foam generator. The results show that air suction capacity first increases and then decreases with the increasing of $$R_\mathrm{td}$$ and $$R_\mathrm{ld}$$ , and air–water ratio increases with the increasing of $$R_{\mathrm{m}}$$ . And the optimum distance–diameter ratio is identified to be 1/3–2/3, the optimum length–diameter ratio is approximately 20, and the optimum area ratio should be 81–144. This study provides a solid foundation for application of the proposed foam preparation technology.