Experimental investigations on the performance of a new design of foaming agent adding device used for dust control in underground coal mines

In order to overcome the drawbacks of foam technology for controlling mine dust, an original design of foaming agent adding device was introduced, and its performance was investigated experimentally under different working flows and outlet pressures, and compared to the conventional jet adding device. The results show that the new design of the foaming agent adding device has a reasonable cavity negative pressure, does not produce cavitations, and has a lower inlet pressure demand with less pressure loss. Furthermore, it can add foaming agent at 0.5%–1.0% and regulate the proportions at this low ratio range continuously and stably, which significantly reduces the cost of controlling dust with foam. In addition, it decreases electric energy consumption and simplifies the foam system with no need for extra boosters. Besides, its effect on suppressing mine dust was investigated in the field via dust sample collections, and the results show that this new device is as effective at dust suppression as the conventional one. Therefore, it is believed that this study laid an important foundation for the widespread application of foam technology for dust control in underground coal mines.