This depends on your fire protection system. The conveyor cost is insignificant. There will be people and other expensive items around that need greater protection. In the event of fire probably all electrical equipment is isolated. You should install sprinklers/deluge over the belt.

Some power stations run hot coal fires to a spreading area and expect/wait for the coal to lie down & stop burning. Not realistic. ■

do not stop the conveyor , if you can smother the fire with mist or appropriate fire extinguisher , install automatic fire fighting equipment , if conveyor is short , or the material cannot get wet, extinguish in the return flight

If the source of ignition is rubbing against a skirt, keep it running until you can approach and extinguish locally .

If you stop it you loose it. ■

Originally Posted by sganesh

Pleae assume that a conveyor is running through a section of a factory which is caught fire.

Will you stop the conveyor immediately or allow it to run till fire is put off?

Please assume that conveyor is running idle (empty running) and the conveyor is having EP plies and top cover is of M24 grade.

Kindly vote & post your opinions.

My freinds marco and louis are both right;

it is no different than fighting a conveyor fire in an underground mine

The fire triangle is present being fuel, oxygen and heat, fuel from the belt carcass, heat from friction, and oxygen from the surrounding air.

Evacuating any and all unessential employees and personnel is first and foremost.

Turning the conveyor off is second, third is flooding the conveyor with water from fire hoses delvering water in a fog flooding pattern:

or delivering a "water foam" to the fire entirely.

Reasons:

1. To cool the fire to remove the heat source

2. To reduce to zero the available oxygen to the fire

by flooding the area with water.

3. To eliminate the conveyors ability to fed on the conveyor belt for fuel

The conveyor will eventually burn itself in half if it is a steel supported or cable supported conveyor, saying that a flat conveyor belt with a solid steel bottom under it will continue to add heat to the fire from friction if left running.

If the belt in question has not burned in half by now the best thing is to let it burn out if the exact location of the fire is unknown.

lzaharis ■

I have been involved with a number of belt fires. Yes, don't stop the belt under most circumstances. However, some safety issues may preclude this approach.

If the conveyor is not equipped to fight the fire from the normal initiating conditions - bearing seizures - and you do not have water quenching from the underside, then the fire will eventually cause havoc if it is not extinguished.

Hopefully, your design can isolate the fire and deprive the belt of oxygen, can deluge the fire with wate on the blaze, by example, not deluge the carry strand which cannot deplete heat and oxygen. Or, if underground, your fire fight plan includes having isolation chambers where curtains locally isolate the hot zone and you have planned for foam or water to assist.

Of course, the belt can be constructed of a flame retardant and heat resistant belt.

The issue is too big to give it justice in this forum. The costs are significant and must be weighed for their respective benefits.

Merry Christmas ■

The conveyor described is simply an item in a burning factory. The fire regulations govern the conveyor the same way as they do for any other item. If you have a fire fighting system capable of treating electrical machinery, e.g. dry foam or CO2, then you might be able to run the empty conveyor. However the cost of such a system would probably outweigh the sacrifice of a belt.

If you do not isolate the electrical equipment then other machinery keeps working in a smoke filled zone. Most fire regulations demand the ventilation fans shut down; so the smoke is intense.

All this for the sake of a belt which should have been adequately attended by sprinklers/deluge in the first place. Where are your factory inspectors anyway?

Please refer to the regulations appertaining to your locale. ■

Thank you Izaharis.

It all depends on the overall scenario, right?

Is this a totally enclosed factory? Is this a meltshop? Is this an open facility? A mine? A subterranean coal mine? Or a combustible products facility?

Are you handling sponge iron? Are you handling radioactive material? Are you handling stone? Is the whole factory on fire, or just a section? Or a dust collector? Are you passing under the ignited section? Or are you starting or delivering to the ignited section? Is this a head pulley fire? Or is this a transfer station fire?

Each and everyone of these scenarios has its particular firefighting technique. Sometimes you cannot use water, sometimes you cannot use anything! Sometimes it's better to see and run.

Each scenario has to be carefully studied. The response has to be carefully planned and drilled. Everybody must know what to do and when to do it.

I have been in fires where we had to stop the firefighters from using water, as there was electric current involved. We had to go in with shovels and guts. Meanwhile another team shuts down the electricity. This was many years ago. I am not sure I would do it again. Nobody was hurt, except from some minor burns in hands and feet, as the material (a metal concentrate), was red hot, and sometimes burned though our boots and clothes.

Sometimes we need to cool the equipment instead of smoldering the fire, as they were Hydrogen and Carbon Monoxide fires, and the correct procedure was to shut down the flow, but this could not be done instantly, as there were large vessels involved.

So the safe thing to do, was to keep everything running and cool the equipment without shutting down the fire, as an explosion could develop with the leaking and unburned gas.

A safe, automatic shut-down procedure normally takes place while we are controlling the fire, but not shutting it down. Evacuating the installation sometimes is part of the plot, sometimes it is not.

Regards,

Marco Flores ■

Originally Posted by Marco A. Flores

Thank you Izaharis.

..........

A safe, automatic shut-down procedure normally takes place while we are controlling the fire, but not shutting it down. Evacuating the installation sometimes is part of the plot, sometimes it is not.

Regards,

Marco Flores

Please clarify how the automatic shut down procedure,,,does not shut down????

Everywhere I have been; shops, offices, factories, warehouses, boozers, mines and ports there are always clearly marked assembly points in case of fire. Evacuation is mandatory and so is shut down above most operating voltages. What you can try to get away with locally is up to the individual. According to the stupid poll half the world shuts down and half the world stays running regardless of the overall scenario or professionally accepted health and safety regulations. ■

Sorry to hear your comments, Louis, I never thought that the poll was stupid. I believe it is an interesting issue.

If you read the other comments, you can see that many of us, with many years of field experience, do not shut down the conveyors, if the conveyor is empty and it is not feeding combustible into the fire. And, yes, an automatic shut down procedure shuts down the factory, but you are not supposed to turn off the fire until a valve is closed and the gas flow turns off.

Nevertheless, even if everything is closed, sometimes very large vessels (pressurized vessels), leak into the fire and you do not have control over this vent flow. You have to wait until the vessel depressurizes, meanwhile, you have to hold your ground and cool the equipment without smothering the fire.

You would keep the conveyors running so that they can pass under the burning section and you can cool them before and after they go into the conflagration. You do not evacuate the firefighters and, sometimes (most of the times for me), you are one of them. The Process Control people stay at the field many times, and, yes, sometimes they die. But this is a different topic that we can discuss at another Forum - How to establish a see and flee scenario.

The safety of the firefighting process depends, not only on the bravery of the people fighting it, but in the knowledge of those involved in managing the fire, if we can call that the process of controlling the fire without causing additional risk to the installations and personnel.

I resent your comments. This has been a very professional Forum and I would like to keep it that way.

Regards,

Marco Flores ■

Originally Posted by Marco A. Flores

Sorry to hear your comments, Louis, I never thought that the poll was stupid..... many times, and, yes, sometimes they die.

.............

I resent your comments. This has been a very professional Forum and I would like to keep it that way.

Regards,

Marco Flores

Absolutely unbelievable. Human lives are being less valued than a bit of burning rubber and a few iron rollers. All in the interests of alleged professionalism.

I retract the statement that the poll is stupid...because it is now downright dangerous. ■

Salamat pagi,

Louis,

From your public profile I can see you live in Indonesia. I lived in Indonesia for 2 years, during the construction and start-up of P.T. Krakatau Steel in Kotabaja, near Serang.

This is a very particular installation. At its time, it was the largest sponge iron plant in the world, by a large margin.

The plant was set-up, with 16 batch reactors in two different units, each unit consisting of 2-sets of 4 reactors, each reactor processing about 800 Tons of ore.

The HYL technology, at the time, was sensitive to certain ores that produced high levels of free carbon. As the plant was made with fixed bed reactors, the particular flow pattern inside the reactor, produced a poorly irrigated section at the bottom of the reactor. This section came out (when discharged), humid and then hot, very hot. The bottom section was filled with inert material, essentially rocks which were separated with a magnetic separator in a separation tower.

The iron ores that produced high free carbon were very difficult to handle, as there were frequent fires (dust fires), in the transfer stations and in this particular installation, in the screening and separation tower that took the hot product from the belt and sent it to the melt shop, or what was called, at the time, the cooling building.

As I mentioned before, there were several conditions that produced hot product (this product a metal concentrate, particularly iron in a form that is called "sponge iron"). It is not uncommon for sponge iron dust, to catch fire. The fire produced by sponge iron has a very particular flame, as the products of combustion are not gases, but solids and the only gases generated, come from the combustion of the free carbon. Nevertheless, the flames can be very hot, and the product, sometimes, reaches melting point. Whe the dust settles, there are no flames, but the product is very hot, red hot.

When there is a sponge iron conflagration, you do not stop the conveyors, you keep them running. You try to shut down the feed to the conveyor, until you can smother the transfer station fire. When a storage building, full of sponge iron, catches fire, you do not stop the conveyors, you keep them running, sometimes covering them with lime and using them to remove the material that is not burning, first, and then, if possible, to remove the material that is burning, passing it through a set of infrared sensing station that will remove the hot material and send it to a specially prepared bin, to the melt shop, or to a simmering patio, to call it some way.

This is, I believe, the scenario that was posted in the first post, a section of the factory is burning, do you shut down the conveyors, or don't you? I don't.

P.T. Krakatau Steel later changed their set-up for 2 large moving bed reactors, essentially getting rid of the irrigation problems in the bottom of the fixed bed reactors. I worked with P.T. Krakatau Steel material handling personnel very closely and I learned many lessons about dedication and bravery. We fought together many fires. We were all exposed to the same risks and environment and we learned how to deal with this tiger in the large scale that was required for this plant. They now say that the tiger became a kitten.

I am particularly grateful to Mr. Wansit, Process Manager in 1978, and Mr. Rombe, Production Manager, Mr. Anton and to all of the material handling personnel, whose names I do not recall, they made the difference.

You are entitled to your opinion, and I respect that.

Regards,

Marco Flores■

This is what happens when your belt is stopped and you have a local fire.

if this belt stops your production , and you have not another alternative the cost of the belt is meaningless. The loss of production overcomes by far the cost of the belt.

In this particular plant they had no choice. we are working on it. so they have.

Marco

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yes it is , good point either you are a good observer or this is your plant.

Marco . ■

By the way, we have lost and seen many conveyors lost due to easily controlled transfer station fires.

The photo shown is the one that looks better, the other photos I have would only show the empty structure having lost all combustible materials inside.

The best way to control a transfer station fire is to be able to either screen the very fine dust, or passivate it efficiently. The other way to control them is to keep an inert atmosphere. You have to be careful though, with the personnel, as some companies have had people injured due to CO intoxication or CO2 replacing the Oxygen in the area. Some companies, on the other hand, have decided that, to avoid the external show that is a dust fire on top of a bin, they enclose it, so that the fire will be confined indoors. Not a very healthy thing to do, but it's done.

If you work at a Midrex plant, or an HYL, y a fluidized re-circulating bed, a rotary kiln, or almost any other DRI process, you know what I am talking about.

Regards,

Marco ■

We have just designed an automated hot material,separator Quench and Dispose and passivation system to avoid deludging the conveyors whan hot material is present. More info soon.

Marco ■

All this for the sake of a belt which should have been adequately attended by sprinklers/deluge in the first place. Where are your factory inspectors anyway?

Please refer to the regulations appertaining to your locale. ■