Application of the Inertial-Impaction Type Duct for a Reduction of Dust Collection Load in Working Places in Underground Mines

摘要

An inhalation duct and dust collector are used in the working places in underground mines, often with a blowing duct to control dust. Some inertial-impaction boards are set in an inhalation duct to reduce the dust collection load for the main dust collector. So we called this duct the Inertial-Impaction Type Duct.The results on small-scale models of the Inertial-Impaction Type Duct show that when we increase the number of the boards and height, the pressure loss increases in liner. However, the dust protection ratio increases but with peaks. So we adjusted the height of the boards to the half of the duct diameter (height/diameter ratio is set to 1/2), when we made the following mockups of the Inertial-Impaction Type Duct models. The results of these large-scale models are as follows:(1) The airborne dust is reduced approximately 40 percent by the mockup models of the Inertial-Impaction type Duct (control speed: 1.0 m/s; pressure loss: 20.1 Pa).(2) The dust protection ratio is increased by more than 20 percent by using Wet Inertial-Impaction Type Duct.(3) The Inertial-Impaction Type Duct reduces the dust very well where the particle size is larger than 10 #mu#m by the inertia-impaction mechanism. The dust protection ratio is also high for the dust smaller than 0.5 #mu#m because of electrostatic adsorption to the duct walls.