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Post by dazbt on May 31, 2013 8:32:14 GMT -5
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Post by Wheldale on May 31, 2013 14:35:31 GMT -5
This thread is getting more and more complicated!!
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Post by dazbt on Jun 1, 2013 0:30:04 GMT -5
This thread is getting more and more complicated!! I agree, it's all to much for me, I'm now turning all my thoughts and concentration onto a week's worth of carp fishing ![:)](//storage.proboards.com/forum/images/smiley/smiley.png)
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Post by tygwyn on Jun 1, 2013 3:51:30 GMT -5
More contradictory than complicated,
Similar to Global warming and wind power reports
Some of these people writing these reports should be shot not paid.
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Post by Wheldale on Jun 1, 2013 4:15:42 GMT -5
Ive looked at a few papers on the net. Back in the 80's and 90's the coal board said there would'nt be a problem with gas and water from mines. Since the closure programs of mines experts are finding many problems! And the experts are giving a few different thoughts as to what will/may happen with the gas and mine water!
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Post by tunnelbuilder on Jun 3, 2013 7:27:14 GMT -5
During my time at the pit the methane drainage was done by drilling longholes usually at least 100' in the rock above the gob, in the tailgate of the advancing face. A packer inserted in the hole and a connection to an 8" victaulic line connected to a vacuum pump to extract the gas. I seem to remember the gas meter on the pipe reading 75% methane, but I don't remember the velocity of the gas being recorded.
Seems to me that filling old workings full of water would result in a static head pressure based on the depth of the workings, for an example workings at 650' would result in 20 atmospheres and a pressure of around 296 psi. This would try to force the water in running fissures or cracks in the strata. If the rock above the coal measure was left intact seems to me it could be drilled from surface and if there is no connection to the workings maybe gas could be extracted.
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Post by rob52 on Nov 11, 2013 8:38:34 GMT -5
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Post by John on Nov 11, 2013 10:11:43 GMT -5
When I first started at Wongawilli in Dec of 1979, I was shown the fan from that district in Appin that was still being examined. It was held on the surface of Wongawilli so it wasn't tampered with. I asked the electrician I was working with how come the inside of the door was so clean, and yet the walls of the switchbox were covered in soot?? That's just how it came to us here, door open and clean... Then that's where the ignition occurred, said I, and he said that's what everyone agreed on who had seen the fan... I didn't hear or read anything in the inquiry where the condition of the fans switchbox was brought up, everyone one wanted to place the blame on the Deputy's oil lamp, which was proven not to have been the ignition point.
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Post by rob52 on Nov 12, 2013 5:43:36 GMT -5
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Post by John on Nov 12, 2013 9:27:38 GMT -5
Again I have to comment on WHY did the electrician have the fan starter box lid open while the power was still on??? I know what AI&S were like, but saying that, if I'd been caught in the same circumstances by my shift engineer, he'd have kicked my arse all the way down the heading to pit top! In the same frame, when I was leading hand electrician on "dogwatch" at Angus Place, I'd have done the same with any electrician I was in charge of, and we rarely if ever saw any CH4.
As at Appin, we at "Wonga" saw plenty of CH4 bubbling out of water holes in the Wongawilli seam, always a constant reminder of watch what you're doing ALL the time, even though we rarely saw a gas cap on a safety lamp or reading on a D6. As bad an employer as AI&S was, we maintained high levels of ventilation.
I'm still at a loss as to why an experienced colliery electrician would work on energised equipment in a gaseous mine..
We all bent the rules sometime in our working lives underground, but to take a risk that put everyone elses lives in danger..........I've no answer for... Was he under pressure??? Problem is we will never know. I have seen an electrician break down under pressure, can't understand why, but it happened, me??? I'm too Bolshy...I had a habit of saying eff off, sometimes to the wrong people, but I got the job done.... I must say though, had I not had good Inspectors, strong law and been in good unions, I might have had a different attitude, but then I wouldn't have worked underground in the first place, risks would have been to great for my liking..
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Post by rob52 on Nov 17, 2013 4:56:26 GMT -5
"if I'd been caught in the same circumstances by my shift engineer, he'd have kicked my arse all the way down the heading to pit top!" =>> They would be out the gate, its inexcusable. however in enforcing the sacking there would be a union stink.
"I'm still at a loss as to why an experienced colliery electrician would work on energised equipment in a gaseous mine.." =>> Agreed absolutely Nuts, they would be out the gate, its inexcusable.
"I have seen an electrician break down under pressure, can't understand why, but it happened, me??? I'm too Bolshy" =>> You have significant responsibilities as an electrician with the statutory responsibility for certifying flameproof equipment as fit for purpose in a Class 1 Methane environment. Good on you for being "Bolshy" with strong character/resolve it is required, some Mining Engineers don't understand electricity, they call it "Lecky Pipe" because just like compressed air and water it is a service to their need.
=>> Probably the least understood component is the energy from electricity that can be released under fault conditions, the arc blast & plasma, superheated air, molten copper + UV light and Sound…NASTY.
Coal operations in NSW endeavour to ensure the first fault is a low energy earthfault (great in theory) previous Coal Mines Regs stipulated <4000V 5A EFL, >4000V 50A max EFL however most operate on 10A or 15A….sometimes these evolved into Ph-Ph cross country faults thereby imposing Ph-Ph fault current over equipment and earth conductors/screens only ever rated for the EFL current, resulting in annealing and often explosive failure of flame proof enclosures because the enclosures were not and have not been appropriately tested for the electrical ph-ph arcing fault scenario (SIMTARS/ACARP report from 1990's identified this but was placed in the too hard basket, and the U/G mining Pwr supplies fault levels and X/R ratios have only increased since then) unlike those developed in the UK and tested at Harpur Hill Laboratory 50MVA (4.37kA) for 0.2 seconds Fault Power and Overloaded Equipment Assessment, up to 6.6kV, 140kW continuous rating.………Problem now is the system capacitive current is creeping up (larger cables predominately plus better quality of the insulation on the larger motors & txfs) and now exceeds "the recognised criteria" to minimise transient overvoltages and ensure they are damped under arcing earth faults, the consequence is voltage escalation and cross country ph-ph faults via the earth conductors/screens/sheaths on cables. The original Macey and MM Cables 11kV Bolted Cable Couplers lacked a sufficient BIL (50kV and Non tested respectively) and suffered from lung affect + had corona and PD at service voltage thus raised the risks significantly, hence the development of the air exclusion plug/couplers which although in use have not been installed everywhere which is an ongoing problem. Use of equipment with fundamental high voltage electrical engineering design flaws due to a failure to recognise the key issues like E Field Stress grading, surface creepage distance brought about by scaling up 415V designs (having had discussions with the MM Cables Design Staff from the 1960's/70's directly involved in the development of the bolted cable couplers) is just plain ignorant, but it is a big industry with lots of inertia ie hard to turn big egos around. The other significant change is the increase in the MVA rating of the Txf's at pit top Appin had 2 x 66/6.6kV 5/6.5MVA Txf's feeding U/G, Modern Longwalls are being supplied by 66/11kV 25MVA Txf's consequence is the X/R ratio of the Fault current for close in faults can exceed 12 thus exceeding the type test rating of the distribution class Sw Gr and the DC offset component of the fault current waveform substantially increases the time to the first current zero hence heating substantially within the flame proof enclosures. The present Aus Std on flameproof enclosures specifies an inadequate X/R ratio at best only suitable for LV equipment supplied by less than 1MVA Txfs.) =>> Always remember...."For HV you don't have to actually touch the conductor just encroach the clearance, it will jump the gap.....One flash and your ash!"
Rob
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Post by John on Nov 17, 2013 8:01:01 GMT -5
A lot to digest after just getting out of bed Rob.....LOL tbh, never really gave it much though about fault currents on 11Kv, always trusted the design engineers, but did come across a fair amount of corona discharge. One longwall transformer breaker did break down and cause a hell of a lot of damage one shift, the chamber was covered in a 1/4 inch of carbon, but the chamber did retain it's integrity, I don't recall if anyone ever found the reason why. I do recall another transformer with a failing through outlet which was blanked off having a corona discharge/insulator breaking down one shift. Pre shift elect reported it to me as an urgent job, so made arrangements to examine it first job... I took another electrician with me as a safety safe guard should I have to isolate and lift the breaker lid. Sure enough we did have to go in and drop the outlet off and blank it to clear the problem.
As you say, once past 1.1Kv, it's just a matter of discharge to any object getting too close, which is a fair way once you get to 11Kv. I had one young electrician burned by not double checking he had isolated a circuit...He was lucky it was 1.1Kv instead of the primary side of that transformer, which was 11Kv..
He was doing an insulation test, lucky he had the megger lead clipped to earth and was going to clip onto a live conductor instead of the reverse, he'd have most surely been dead the other way round. No way either myself or the Deputy could cover this one up, he had to be rushed to hospital, and they send a report back to the Manager. So had to go by the book.
The Elec Inspector insisted he be fired, our Engineer pleaded his case and persuaded the Inspector to be lenient as there were extenuating personal circumstances.
The Engineer brought in some new rules into normal working practices and insisted all of us adhere strictly to them.
His standing rules on 11Kv though were strict, permit to wok shall be issued by himself or a shift engineer, either one elec and an engineer, or two electricians, one being a Leading Hand, will carry out the work, list of instructions for isolating and earthing circuit to be worked on, use of the hign voltage testing "stick" MUST be used before any work is commenced. Then the job signed off at the end of the shift by an engineer..
Wonga had a different system, they were on 6.6Kv...Each shift had a shift Elec Engineer, and Management insisted at least one electrician or Leading Hand was authorized to switch and work on HV circuits. I was going through the HV training shortly before I left to go to Angus Place. I spent a few shifts walking the HV cables, making note of where they went, where the outbye subes were located, and isolation procedures. Once I had gone through everything with my Shift Elec Eng and he was satisfied I knew where everything was, I had to come in one dayshift and draw a HV layout of the pit, listing locations of all HV subs underground by cut through numbers. If he was satisfied, I'd have been authorized for HV work.
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Post by rob52 on Jul 21, 2017 8:16:47 GMT -5
Noted posts above Nov 12, 2013 at 12:38am & Nov 12, 2013 at 9:43pm At Appin Longwall commenced May 1969ish when not gassed out....per 1982 AJ Hargraves Key Note Address re CH4 Drainage.... "Although pillar extraction goaves was known to release gas from adjoining seams, only with the commencement of Longwalling at Appin was the commencement of conventional CH4 post-drainage seen"...Appin presently runs 54 x 1MW Gas reciprocating Engines on pre block drainage & goaf recovery...also have VAM unit and still have to flare residual!!!! mid 1990's with Coal price crash to $70 US for Coking Coal (pre the 2001 onwards price rise to $400 per Tonne in 2008) we were mining CH4!!!! [10/30019] 1979-80 Enquiry into Explosion at Appin Colliery: 1979 [General file] (SF 521B); Resources Regulator issues CH4 Exceedances Prohibition Noticewww.miningmonthly.com/coal/mines-coal/appin-withdraws-workers-on-gas-fears/“30 Jun 2017 - …The Resources Regulator concerns mount over the levels of gas in the mine…….
The Resources Regulator has issued a prohibition notice and expressed broader concern regarding the recent gas exceedance events and the operating practices of the Illawarra Metallurgical Coal operation.”Stating the obvious..."Effective gas drainage and main ventilation systems are essential for the control of gas and the safe operation of coal mines." …..it is always good to work for an organisation with a technical memory beyond the last corporate restructure. Rob
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Post by rob52 on Jul 21, 2017 8:37:17 GMT -5
Appin Colliery Explosion 24 July 1979 Published on Mar 15, 2015 TV report into the Appin explosion and inquiry. Lest we forget...the price of CoalBroadcast May 1980 - Discussion on the Appin Colliery Explosion Judicial Enquiry - 9mths after the explosion 24 July 1979 Coal Mining is a Dangerous Occupation Tradeoff of production V’s Safety “The Main problem about the operation of the Appin Mine is that it has not been possible meet the requirements of the Coal Mines Regulation Act”CH4 often twice the legal limit Mines inspectors knew of the CH4 exceedances and tolerated the CH4 exceedances Appin Colliery Explosion 24 July 1979 14 Lives lost Jan 1979 - Letter from Department Feb 1979 - AIS Letter response Oct 1979 - Department replies requiring corrections Mining is a Risky Business.....to Jail with Weasels There was no application for the ventilation system that was in place when the explosion occurred. Appin extraordinary Levels of CH4 Bob Aachen Dave Edwards Heath Bruen Mine Deputies Ron Mulock Minister for Mines NSW - Inspectors allowed breaches of the CH4 Limits. Often 2 x the Legal limit - Set up the Inquiry in compliance with the Act Political SpinJudicial Inquiry Judge Alf Goran 7Months $1M Cost Basic flaw in the Inquiry Mr Brian Murray Experienced Sydney Barrister - Counsel Assisting & also Represented Mr Mulock Minister for Mines NSW =>> NSW Bar Association - Says this is highly unusual/abnormal/inadvisable, thus not impartial =>> NSW Bar Association - Says no one impartial assisting the Judge Feb 1980 Power blackout - CH4 greater than 9 x the legal limit for 30Hrs before detected, just 6mths after the explosion Appin Underground Footage After ExplosionPublished on Mar 15, 2015 A description of experiences from some involved in the Appin Mine Explosion, NSW July 1979. This footage has been obtained with permission from the documentary Beneath Black Skies. Appin Mine Disaster MonumentYep...that technical memory matters. Rob
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Post by John on Jul 21, 2017 12:11:15 GMT -5
I started at Wongawilli in Dec of 1979, and we were taking about the Appin accident, both Collieries belonged to AI&S. I was shown the aux fan that had survived the explosion. As soon as I looked at it I said "how come the inside of the door is clean and white and yet the inside of the starter was covered in carbon. Elec I was with said this is exactly how it was found, door open, a fault on the starter and he went on to say the transformer had tripped out. Looks to me as though this was the point of ignition, to which he stated it's same the opinion of every other electrician who had seen the fan. I recall the inquiry into the accident, and from recollection, everything was swept under the carpet, the Judge would not place blame on anyone. So was left open..
My theory is the electrician was working on the starter with power still on it looking for a fault...nuts!! It was only a simple starter, he could have found the fault in minutes. At the time of the explosion, AI&S was pushing for coal, they had little stockpiled at Port Kembla, but even at that, we had a strong union, the elec should have told the Deputy to take a flying leap, I used to, when it comes to safety, job stops until it's sorted out.. Been there, done that and have dozens of Tees shirts. I was the Deputy's worst nightmare.
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Post by smshogun on Aug 5, 2017 14:50:23 GMT -5
It all comes down to commerce and what needs to be paid out and what return they can make, and what Government (our money) subsidies they can get.
Many options for gas exist and the prime gas is HHO which is two parts hydrogen and one part oxygen, and by leaving the oxygen molecule in it is a much hotter burning gas and much more efficient, but it is also cheap to produce, easy to store, can be made on demand, and used in most petrol engines with a simple conversion kit or run directly in gas turbine engines, and here is its downfall, its too cheap and easy.
Many factors are in play here and the main one is how much money can Governments spend as its only our money, and how much can they make in profits for industry. By running down gas supplies they can use the fear factor and use this fear to manipulate the public to allow them to spend more money than is needed and people accept this, but what do you need to generate HHO? only a small HHO generator which is stainless steel plates and a supply of water, using electrolysis you can generate around 80 litres of HHO per minute which is more than any household could use, and we only need something such as solar, water power, or even a battery to generate the power for electrolysis.
This is why Government don't want it, every household could install a solar panel, a water wheel if water is available, or simply charge a battery or bank of batteries from the mains; and use this to store electricity and generate their own HHO on demand, but look at the economic factors in play. Currently we have separate entities selling gas, by installing our own gas manufacturing these companies as retailers fail and the Government loses taxes, the distribution is handled by another company and this would fail as there would be no need to store gas if people could produce it on demand, and remember we are all paying these companies for a commodity, and their shareholders profit bonuses.
So, are we out of gas? NO, we just need to remove the commercial element from it and we can produce our own readily and easily, and HHO is merely one of a number of fuel gases which can be produced.
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merlin
Shotfirer.
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prop and lid
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Post by merlin on Nov 23, 2017 12:42:00 GMT -5
at bersham colly n wales a shearer was cutting when a flame shot out of the disc it was like a flamethrower it woundt go out put water fire ex then all of a sudden it went out it was blower the picks ignited it
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