Dust distribution at a coal shearer in the face area

Abstract

Compliance with the Federal Code on Safety in Coal Mine, §22, No. 550 as of November 19, 2013 (as edited on January 1, 2020) dictates air dustiness and dust deposition control to be implemented in mines using stationary and mobile facilities. Application procedures of stationary controllers should be science-based and tested to provide reliable information. In particular, the procedures should indicate installation sites for the controllers and dictate revaluation of readings received from the controllers towards the dust explosion prevention in mines. Aimed to develop a framework for such procedures and to revise measurement areas for the movable controllers, dust distribution in roadways was studied. The studies have found out that particulate emission and dust distribution in the face area is complex due to mobility of the source of dust in the coal face area. Characteristics of dust particles govern their behavior in air flow. Thus, it is required to know characteristics of dust particles at the dust emission point to track their travel in roadways. A dust sampling procedure was developed to sample dust at a coal shearer. The data on characteristics of dust particles were also obtained. The mine and laboratory test results were used as the initial and boundary conditions in computational modeling. The mine researches and the modeling show that air flow is split into two parts in longwall. Dust produced by coal cutting by the shearer moves with air flow above the armored face conveyor. These results highlight the importance of taking into account local and head drags when selecting installation sites for controllers of air dust content and dust deposition in coal mines.