Coal stockyard fire protection and fire fighting systems
I am looking for information on coal stockyard fire fighting and protection systems.
We are designing a 100 000 tones coal stockyard (200 m x 90 m) with a maximum high of 17m. Its is of course located very close from a stacker and a coal reclaim conveyor. In addition a sulfur stockpile is located 45 m away.
Our intention for the moment is to install fires hydrants to water thin layers of hot coal on the ground in case of auto combustion. We do not intend to use these hydrant to water the coal pile in case of fire. We would also install equipmenst to make water curtains and protect the stacker, the reclaim conveyor and the sulfur pile in case of major fire.
Do you have any experience, opinion or advices on this subject ?
I am looking for feed back on closed coal conveyor equipped with amber detectors or fire wire detection system. Please could you tell me if you have such systems installed, if they are accurate, reliable and if you are satisfied ?
We are currently designing a 100 000 tons coal stockyard. We are located in an area receiving about 2 m of rain per year. The natural ground on the stockyard area is made of yellow limonite (mud when it rains). We are planning to install the coal pile on a foundation made of:
- 40 cm of calibrated gravels containing drainage pipes
- 40 cm of compacted coal.
This is supposed to prevent water from percolating through the ground and coal fines from polluting underground water.
Surface drainage will me made using a circular open drain around the storage area.
We previously looked at a concrete foundation but we fear settlement and maintenance problems due to the nature of the natural ground.
Please could you tell me if you have an opinion on this or any feed back from your own experience ?
I reviewed a powergen design in Taiwan which intended to spread out burning coal & quench it. Who did the work & how much they got paid was never answered.
There was a rapid take out conveyor to a spreading area where the burning coal was drenched. To be honest I never gave it much attention; it was not in my scope & I was too bewildered by the suggestion to be able to speak. I still am. The Contractor was the English arm of a major French parent EPC, with whom you are no doubt familiar. Neither party are renowned for acheivement, technical nor commercial. Better to rely on the proper fire fighting system, which you are installing anyway, rather than throw funds at some intermediate airy fairy scheme. The burning coal is hardly likely to lie down in front of your hydrants is it?
Fire wire stuff---can't comment.
Only the depth of the gravel bed is relevant. Compacted coal is coal for all that & cannot make a contribution to reducing groundwater contamination. Quite the reverse, since the rain will percolate through large flat areas of coal when stocks are low. Tighten up on the reclaimer accuracy & reduce the depth of the coal bed as much as possible.
Here we go again..if your ground conditions do not favour a concrete hardstanding then you can look forward to some fun & games when you run a fairly concentrated load of a 400tonne reclaimer up & down the tracks next door.
Drains should be large enough to accommodate the predators which might drown during downpours while asleep; after eating the rodents which will surely nest in the drains.
If you decide to go this route you will have problems a plenty due to ground water contamination from heavy metals, residual oils,
radon release from the coal etc.
How close to the surface is your bed rock? that is number one as it will channel all the coal drainage that escapes from the stock yard and pollute everything down stream/down gradient from the stock yard.
You can not spend poorly in regards to the foundation for the reclaim system or the stockyard
as it will cause many problems due to run off and
ground damage due to poor footings/fooundations.
Over here in the states we use what is called popcorn shale-shale that has been heated in a coke oven and allowed to expand/pop to aid in flotation
and better foundation support. arte you designing water diversion ditches around the stock yard to move water away from the stock yard? you must do this!!
In all honesty you should re-examine a concrete foundation using a floating slab for the reclaim and stock yard as this is the only thing that will hold up and allow you to collect and process the wastewater from the coal assuming you are using a clarifier and sludge system-I hope anyway.
You should in any case plan on a 2X double depth foundation due to the bad ground you have if you can not bring in good gravel to support it-any good civil engineer/architect will help with this.
Perimeter drains sre fine but they are only as good as the design or the material used to make the drainage system. Concrete is the only sure way to contain it all and reduce pollution to a minimum.
Firewire by Kidde is a system designed for enclosed areas, If you have plenty of water you should invest in deluge guns and baking soda for supression and control to create a soda pressurised soda stream for fire suppression rather than Firewire.
You will want deluge guns at your transfer points anyway due to the coals condition.
What are you burning lignite?!! sub bituminous??!!
The storage dome solution:
Have you considered a covered storage silo/dome/with a center reclaimer with CO2 flooding and soda stream for fire suppression? It is easy enough to do with a dome storage.
A large dome with suprssion consisting of both the above fire suppression methods will control and reduce waste water runoff and keep the coal dry reducing combustion potential and reducing the energy needed to dry it for use.
The round dome storage allows you to fill it completely to X capacity and have a circular foundation in X diameter to allow for all your storage needs and allow for simple coal water runoff control with reclaim and stockpiling done by the same conveyor/boom unit-the reclaimer/stocking conveyor will have additional fire suppression installed along its entire length in addition to water dust suppression eliminating the ned for all the extra hydrants etc. Ialso allows you to continually monitor the pile as you are reclaimning it and adding water or soda stream
as needed for control of coal temps from spontaneous combustion.
You will only need a small loader for clean up if you empty it completely as well rather than a tracked or rail mounted reclaimer with less work- just make sure to plan for and install a a bridge crane or Jib boom crane for motor or gear box replacement during the design stage if you go this route- a lot less area and fewer headaches for the work involved with less labor and risk from combustion of the coal-open piles are subject to sunlight which adds heat which adds to smoldering fires which will add too spontaneos combustion potential.
The construction of a dome allows for a substantial foundation for the coal and reclaimer in a smaller covered area which eliminates runnoff water, reduces the conveyor needs to a single central reclaim point and stocking point and one discharge conveyor either in and underground gallery or discharged through the side or top of the dome if you wish.
The domes natural construction will allow you to collect your clean rain water in ponds and use it for fire sppression and dust control as an added benefit and reeduce runoff pollution
There is one firm in Houston Texas that has built a lot of domes with central reclaim units unfortunately I do not remember thier name but I do know that they do work world wide.
and have done domes for coal storage and reclaim.
If you Google "storage domes" they will come up quickly I am sure.
The fire triangle consists of:
Fuel, Heat, Oxygen,
if any of the corners of the triangle are removed a fire will die!
The design of a dome will allow you to flood it with carbon dioxide and or a soda stream to control a fire and or smoldering without human intervention.
Your turn John- if I missed anything my sincerest apologies.
Its all there! A dome would be ideal. We used one for Ho Ping in Taiwan (here's hoping its still there)(sometimes you can't resist) where that famous builder, who we can't name, had turned the dome inside out so that coal dust could not settle on the (otherwise) internal framework. A tidy bit of American know how there. Perhaps they could make it even safer with plenty of explosion relief flaps & without inerfering too mush with the strength. They, whoever they are, know best anyway!
You have the opportunity to solve your storage problem once and for all by putting a smaller dome on half the stock yard when it is half empty and installing a second dome when the other half of the stock yard is empty and solve all your current and potential pollution problems as the coal will not get wet in the dome at
all as I mentioned before regarding all the benefits for same.
and any coal sludge will be almost eliminated.
A single drawdown belt underground gallery common to your "potential domes" can be done easily as it will not be in the way and will be there for the second dome when the second dome goes up.
with bedrock as close as it is in spots you are going to have pollutionn problems period.
John and I and other members of the board are and were stymied because you have not provided a diagram of your facility
and did not tell us everything.