Investigations for improving the environmental conditions of the longwall faces in Yotsuyama Mine, Miike Colliery, were conducted using new ventilation systems. The E-shaped ventilation system is the one and the W-Shaped ventilation system is the other.
The results obtained are
(1) Both systems are effective for controlling the environmental conditions of the face worked in highly heated surrounding rocks.
(2) Ventilating by Wr-System, labour intesive areas are placed in fresh air and the total capacity of heat exchangers required for a face including face entries are only 60 to 70% of that required in the Ur-System.
(3) In the Wr-System, two patterns of ventilation air flow is observed due to the different flow rates in the two intake airways.
(4) In gassy areas, the Wr-System could be inadequate because of the tendency of fire-damp accumulation in the goaf. In such cases, the E-System should be applied.
