Ventilation of Longwall Workers in Tailgate Roadway MRE 19th March 2018
MRE – Grosvenor Coal Mine — 19.03.2018.pdf
The Gas Management Audit planned to commence today would be postponed until the Mine had overcome the current gas management problems.
Question From Marlborough about turning the bleeder road into a return appears to be a flat No.
Marlborough ask for the Ventsim for the Mines Decision to reject this option and to Management proposing the use of a forcing auxilliary fan in the Tailgate for Maintenance in the Tailgate.
Obviously this means that there is over 1% CH4 in the General Body in the Tailgate Roadwayeven with no Mining occurring and they want to use diesel machinery in the tailgate.
Is this because there was not enough Secondary Support Installed (including passive supports) in the Tailgate Roadway before longwall mining commenced
Is it true that the Workers had to man handle props (they used wheel barrows at one stage), air tracks etc to get supplies in over a 1km?
Can the air around the “bleeder road” be reversed and this would allow suction to be applied to inertisation lines through the perimeter goaf seals on the TG side of the bleeder to draw the methane fringe away from the TG end of the face
Other options discussed during open forum
Reconsidering if the bleeder could be made a return. Inspector Marlborough requested a copy of the Ventsim model which was the basis for the Mine decision to discount this option and the Ventsim model for the use of the auxiliary fan
Installation of a forcing auxiliary fan for more air into TG for access during maintenance shifts was discussed. Inspector Marlborough indicated this would require a methane sensor inbye of the ducting closer to the TG drive if it was to encroach into 400m from the return end of the longwall
Inspector Marlborough stated that he would expect that the use of this fan would reduce air quantity through the face. Mr Webber agreed that the trial conducted the previous week gave approximately 12 m 3/s at the end of the ventilation duct (1400 m in T C) but the air quantity across the face was reduced by 10 rn 3/s.
2.2 Other options discussed during open forum
e Cutting intake methane pollution by spraying the ribs in the bleeder road with shotcrete. It was obvious from the Citect screen that the MG Methane monitors on the LW were reading approx. 0.45%. This is intake contamination from rib emissions in the bleeder road
e Cutting the ventilation quantity through the longwall reducing the goaf wash and the venturi effect of the high air velocity across the Longwall. Currently 80 m 3/s across the Longwall face
2.0 Close-out Meeting
This was attended by the Inspectors plus Mr Ivers, Webber and Griffiths.
Inspector Marlborough made the following points —
2. Consideration to be given to a reduction in ventilation quantity through the longwall.
