239 posts
coal savings
I have hot air source from grate cooler at 250 degree @ 190000 m3/hr. I have a ball mill with auxiliary furnace whose tph is 9 tph with coal input moisture of 10% . The fine coal moisture is 1 %. CV of coal is 7000 kcal / kg coal. How can I calculate the saving of coal if i use this hot air & stop the auxiliary furnace? raj
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41 posts
Re: coal savings
1 What's the landing cost of 7000 kcal coal ?
2 9 tph. Is this the capacity of coal mill or auxiliary furnance? if it is coal mill capacity any do you have any rough figure of how much caol presently you are consming for HAG?
138 posts
Re: coal savings
xxxx,
It needs 58.5 GJ to heat 190000 Nm³ from 20°C to 250°C .
If your coal heat value is 27 GJ/t , 58.5 GJ represent 2.17 t coal.
(did you mean Nm³ or actual m³ in your post ?)
However, in principle, it is not possible to answer your question without knowing more about the milling/drying plant you are considering. See this thread .
also do not understand your question very well. What are these 9 tph of coal? Are these the quantity of coal you burn in the dryer, or is it the quantity of coal you need to dry ? Ideally, you should better include a drawing in your post.
It is quite possible that 190000 Nm³/h is more than what you need to burn the coal you need for drying purpose. To burn 1 ton of coal, you need (stoechiometrically) typically 8500 Nm³ of air or 16000 Nm³ for 10%O2 in the exhaust.
Finally, note that using hot air directly to dry coal might be very dangerous.
Lal
239 posts
Re: coal savings
9 tph is the capacity of coal mill means the output of coal mill . I do not know the amount of coal fired in the auxiliary furnace. my question is how can i calculate the amount of coal i am using in the auxiliary furnace and that amount of coal will be saved by the use of hot air from the cooler. please send me in detail rajmadhuri1972@yahoo.co.in