dear deepakvermaa

i hope you are going ahead with the solution

i add only questions

is the conveyor enclosed or open

is a dryer for the coal before the belt conveyor

is the coal wet or dry

which is the size range of the pieces or particles

+ for CO2 fire fighting it is quite better when it is closed and the is volume not too large

+ in case the way to feed is not too long and it could explode you can consider an shock pressure resistant chain conveyor

We would be pleased if you send us data, drawings, ...

Regards ■

Would this be for the coal on the belt, or the belt/rollers caused by machine malfunction? ■

Originally Posted by deepakvermaa

Greetings & Salutations,

I want to know the best Fire Detection & Fighting system / technique one can adopt for COAL CONVEYORS BELTS?

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There are many variables to consider about your inquiry in which to develop a hypothesis do the experiment and come to the conclusion.

coal conveyor location being:

surface;

exposed to the elements with all weather covers.

A below ground drawdown gallery in a cut and cover surge pile installation.

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underground

main line galleries for exhaust side outby belt installation

" " " " belt route travel from fresh air inby to exhaust air outby galleries.

access door clearances and door gaskets to seal electrical equipment and reduce flash over damage to controllable levels with close tolerances, exhaust side outby main line galleries for beltlines.

whether explosion proof fixtures and motors are required and how they are fully capable of containing explosive gasses to the point where they can and will blow the cover off of a control box on a radial stacker and injure or kill someone-been there done that......

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Your question is too broad for one answer;

So much depends on housekeeping to prevent spontaneos combustion from coal fines in both surface and underground locations.

the laws that are applicable and enforced by regulatory agencies if any.

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there is no one answer for your question as fire and explosion prevention are a hand in glove item and are not separable when it comes to coal.

many mines have sprinkler systems along the main line inbys and outbys where conveyors are located.

many mines and conveyors simply have fire extinguishers at transfer points.

many mines that deal with high combustable gas concentrations of methane, hydrogen sulfide, and other gasses use remote monitoring to control the conveyors and mining equpment shutting them down when the sensors detect gasses at a certain concentration.

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In order for you to become well versed and intimately involved to understand fires and especially coal fires regarding fire prevention involving any type of coal and conveyor you will need to spend time learing the basics of fire and explosion prevention/mitigation and control from the NFPA, Loyds of London,

national fire underwriters, the european fire underwriter and fire prevention organization. the united nations regulations for combustable goods,

the mine safety and health administration, the canadian mine safety administration,

You have to become intimately familiar with the fire triangle or the four corner fire triangle as it is referred to sometimes due to combustable metals to understand what is involved in fires as asking just about coal fires will get you no where.

you should seriously consider attending the new york state fire academy at

Montour Falls New York USA to begin your training and understanding of fires and fire prevention to give you the basics to understand how a fire becomes a fire-many people do not realize an explosion of any type is a supersonic fire which creates the mess and fire damage.

lzaharis ■

OK, so now we know the problem is coal burning on the belt.

I don't know what is used but maybe some logical thought will produce ideas.

Coal is burning so -

1) it gives off heat

2) it gives off CO2

Maybe provide a thermal sensor(s) over the belt to detect burning,

or maybe pass the carrying belt through a tunnel provided with CO2 sensors.

These would monitor the coal for burning.

Then pass the belt under a water quenching station to extinguish any fire found by the monitors. ■

Originally Posted by vnspramod

fire extinguisher service is used to extinguish all type of fire, this can applicable coal fire, vehical fire, office fire issue. etc

So what is your solution to detect the fire?

Explain how your fire extinguishers are integrated with the fire detection system to extinguish the fire on a moving belt conveyor? ■

Hi

I'm looking at solutions to detect (and prevent the spread of) fires on underground conveyors. I'm most interested in fires resulting from collapsed bearings or other forms of rubbing leading to combustion of spilt coal fines. Although the coal in the mine I'm looking at is highly spontaneously combustible (by New Zealand standards), I'm not too concerned about buring coal on the conveyors...it's not a problem we have. However, my research has come up with some useful information from the UK regarding infrared detectors. Check out http://www.patol.net/convguide.htm These guys are really help too, so drop them a line.

In case anyone is interested we're looking into pilot operated deluge systems on the high risk areas of our conveyors, i.e. drive-heads, transfer points and loop take-ups. This is because the airflows in the belt haulage are quite high, escecially near the surface, and conventional sprinklers won't always be able to detect heat close enough to where it's being generated. Where we can we'll install normal sprinklers.

Where posible we're adopting NFPA guidelines, but the Australians also have a new Mine Design Guideline (MDG 1032). These are always a good starting point...as is the bias/preferecne of your insurance underwriter.

I hope this helps.

Andrew ■

There are many aspects to fire protection, detection and control:

Prevention-Protection:

Prevention-Protection is the first priority and involves eliminating dust build-up through a series of design conditions. Today we rely on special chute design geometries to enhance flow and minimize dust liberation. In order to quantify dust, you must know the gas dynamics and turbulence effects within and beyond the chute.

There are classical formulations of the production of turbulent flow that will place particles into suspension. Special chute geometries both minimize turbulence and confine the turbulence generated to localized zones that can be partitioned. Then entrainment is somewhat controlled by creating stilling chambers to reduce the velocity and increase retention time to allow particle decanting. Make skirts longer with higher belt speeds.

Higher belt speed will contribute to dust generation. Economy versus protection must be given consideration.

There are common sense methods of minimizing dust such as carry back and materials entrained or attached to the belt that will bypass belt cleaners or escape through openings in skirts and related containers.

Counter-flow in tunnels will liberate dust on the coal surface. Knowing the degree is necessary. We have placed hood covering to partition counter-flow and enhance with-flow turbulence control.

Design of structures around the loading station should have minimum components that allow settlement onto surfaces that can create sufficient piles for fulminating damp conditions. All surface shapes should be developed the shed dust including special coverings that enhance gravitational

Dust abatement through dust suppression devices and materials such as nebulizers, sprays, ....

Wash down regime.

Detection:

Sensors at loading/discharge where most first will start - infrared, smoke, high temperature, ..... Dust monitors

Mitigation:

Detection and partioning of the fire-smoke zones often apply foam curtains to seal the fire zone once high heat and smoke is detected

Detection by "Protecto-Wire" type systems is often used to identify idler bearing fires along the conveyor and around the critical rotating equipment.

Water sprays have been applied to quench the high temperature idler and drive machinery locations, especially in tunnels.

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As others claim the subject is quite vast and is continually changing. User groups gather to discuss this subject on an annual basis. You should become informed on their insights through SME, et al, such as:

http://www.prbcoals.com/pdf/PRBCoalI...protection.pdf

Good Luck, ■

Thanks, Lyle, for the web links. It's clear that great minds think alike, because I had already visited these web pages. Although we have over 6,000 metres of U/G conveyors, our focus is on the transfer points and drive-heads given the propensity for the build up of fines in these areas and the value of the assets. As such, our efforts are prioritised on detecting a fire at these points in time to put it out before it causes too much damage. Naturally, housekeeping regimes are critical to the prevention aspect of the fire "life-cycle", so this is also an imnportant part of our solution.

The reason I'm babbling on is that we've decided (at this stage) not to use LHD at the rotating elements, but instead sue fast acting pilot detectors that activate a water deluge system. In the future I'd like to see LHD running the full ,ength of the conveyor system, but the cost will be significant as you can imagine.

However, on that note, does anyone out there have experience comparing different detection techniques in/around the drive/loop take-up/transfer points on U/G coal conveyors? I appreciate that the design of these systems will have a big impact on the soluiton, but any further feedbaclk would be welcomed.

Cheers

Andrew ■

Hi Lawrence. I'm noe to this forum thing, so am still learning. I had meant to post a reply specifically to your response, but I see there's not necessaarily a specific link. Anyway, thanks for your response. It looks like it will prove useful, not least because it aligns with some of the work we've done!

I appreciate your response.

Andrew ■

Andrew,

I am happy to continue discussions on the forum. I also have my email on the bottom of each posting made. ■

dear all:

does anybody has the idea or tools for catching the belt when conveyor belt broken?

so many thanks

john ■

Conveyor systems in general have a fire risk due to external events and equipment

failure. However the flammable nature of coal including the ability of some types to self

ignite introduces an exceptional hazard requiring special consideration. ■

Fires on conveyors are rare but the fire possible is considerable. In incidents, which have occurred, the damage has been severe, particularly where conveyor fires have reached and enveloped the destination e.g. Boiler house coal bunkers as in case of thermal power stations. The design of conveyors is that the wind tunneling or chimney effect is an inherent feature on inclined conveyors and this causes rapid spread of fire through the conveyors.

Best Fire Detection & Fighting system / techniques are Fire Hydrant, Sprinkler System, MVWS, HVWS System, Transformer Fire Protection - Nitrogen Injection System, Fire Alarm - Conventional / Addressable, Gas Suppression System FM200, Inergen, Novec, Argonite, CO2 Gas Suppression System, Fire Tenders - Water, Foam, DCP and Multi Purpose Tender, Trailer Fire Pump, Portable Fire Pump and Fire Extinguishers, DCP Trolley - 150kgs / 250kgs. Gas leak Detection Systems - LPG, Hydragen , Sulphur Di Oxide Etc.

For quality safety products you can refer https://www.sos-safety.com/ as they have huge collection of fire safety equipment. ■

This last post...or so it should be. Since starting over 8 years ago there has been a dearth of really meaningful comment apart from Isa Harris's reference to the NFPA Handbook. I would reiterate Mr Harris's recommendation for that best source of information. ■