Why this Ad-Nauseum attention to PUR as a contributor to a methane ignition on the Longwall Face at the Grosvenor Inquiry? What about other just as, or more likely Ignition Sources?
For the last several weeks, we have heard ad-nauseum about the the complicated scenario of a
A small intense PUR driven spontaneous combustion event that no one detected prior to the event suddenly flares to over the ignition temperature of methane from around 150C to over 540C in seconds.
More this heating is within metres of the back of the longwall chocks in the immediate area of around 100 chock.
This has been to the now total exclusion of any other ignition and gas source.
METHANE SOURCE FOR IGNITION LW104 FACE.
Why has no-one mentioned the possibility of floor blowers?
Grosvenor has a proven track record both in Development and Longwall faces, of blowers from the floor seams releasing thousands of cubic metres of Methane in less than an hour.
There is a defined zone from previous 4 years of HPI’s that the zone of floor blowers is inbye 20c/t
The blowers manifest with floor heave events, which occur through abutment pressure.
There is a morbid fascination over an increase in the Tailgate Leg Pressure from 380 to 390 bar coinciding with the Face Ignition during evidence. An increase of 2.6%.
I would bet London to a brick, that if Grosvenor (Investigators and Consultants) bothered to to check records from previous documented floor blower HPI’s in the Longwall, they would find similar changes to chock leg pressure at the same time as the floor blowers.
Wherever Methane has come from it cannot ignite without an ignition source
IGNITION SOURCES
I am only going to look at one potential Mechanical Source.
The Armoured Face Conveyor
I am informed that the AFC was running at the time of ignition.
No-one has mentioned the extensive repairs done to the AFC that started in the early morning of the 5th of May and finished well over 24 hours later in late morning of the 6th May.
The explosion on the face occurred at 2:57pm on the 6th of May
The AFC was experiencing difficulties operating, jamming and having to be “hard started”.
Some of the Reasons being that
Flight bars were missing/jammed.
Links in the chain damaged.
Yet unless I have missed something the Armoured Face Conveyor has not been mentioned in any form.
Certainly not that it had suffered extensive damage that had taken nearly 30 hours to repair that had finished hours before the Explosion.
HOW and WHY DOES SUCH AN OBVIOUS IGNITION SOURCE NOT EVEN RATE A MENTION?
