Ultimate length and capacity of production heading with regard to gas content, considering nonuniform air flow

摘要

Procedures for calculating permissible length and capacity of a fully mechanized production heading with regard to gas content and considering nonuniform air flow across and along longwall are described. Nonlinear relations are derived for methane concentrations and air leakage into mined-out area. It is proposed to assess a production heading capacity based on the gas-related permissible length of the heading and the coal cutting chart with a shearer. It is found that the increased gas content of coal and higher air leakage into mined-out area results in reduction of gas-related length and capacity of production headings.