This is a hearth question not a furnace one. I have a bag of coke that was given to me decades ago. Today I tried igniting it in the hearth using a wood fire; half an hour later the wood was nearly gone and the coke was happily sitting there, untouched. I looked for my bag of charcoal but it must have been thrown out 2 years ago during the great shed re-vamp; no joy there either. Any tips from someone who uses coke? Cheers Charlie
Charlie, I have not burned coke myself. But, I did find quite a few vids of blacksmiths discussing starting coke fires. All of them seem to start a small paper/cardboard/ wood fire that is supplied with some forced air. Once the starter fire is going they add small amounts of coke and continue to blow air up through the fire. After that it is just a matter of continuing forced air and adding coke as needed. Denis
Normally you use coke to start a coal forge. Basically create a small teepee fire and pile the coke around the base up about 1/4 the way up the teepee. Coal goes around that. Light the teepee as it gets going good add in some forced air. As the coke lights and the wood burns away rake the coke into the center and start bringing the coal into the edges of the coke mix. It's a tough thing to get right. You need to get the coke hot enough to start converting some of the coal to coke and burning. Too much air too soon causes the wood fire to go out or burn too cold to light the coke and it just smokes. Not enough air the coke just smokes and never lights. I haven't worked with coke/coal since I was a kid and always with someone knowledgeable around adjusting the little things that I didn't grasp as a youth. SO this explanation is very much basic, and probably one of a dozen ways to start a coke/coal fire.
Thanks Denis, I should have mentioned that that is what I did. Perhaps my small fire wasn't big enough; there were encouraging burning-coal smells though.
Thank you for that. Seems like too much work for what I want to do, which is to heat some steel to orange-heat, so that I can forge it. I think I need to dig a pit and start making charcoal again, Cheers Charlie
I'll bet you were on the right track. Coke won't volatilize until it gets up around 1100F. An unaided (no blown in air) wood firemight max out around 1100F. So, a hair dryer or similar (bellows?) may be necessary for success. "In addition, the ignition temperature of petroleum coke has been determined as being 593°C com- pared to 482°C for high volatile bituminous coal in previous bench-scale FBC testing." Denis
I run a coke fueled blacksmith forge. You need a decent starting fire and lots of air to get a coke fire to become self supporting. Coke doesn't contain volatile compounds like coal so it doesn't go through pyrolisis and burn with a flame, you have to get the carbon to ignite. The ignition temperature of coke is 700C / 1292F, which is much higher than charcoal at 349C / 660F. To establish a coke fire you need to get enough of the coke burning so that it produces not only enough heat to heat the unburnt coke but also the high volume of air from the forced induction. Without continued forced induction, a coke fire will die out in a few minutes. If your coke is damp or there is high humidity, it can be very difficult to light a coke fire because the moisture in the coke and induction air saps out too much of the heat to get it started. On rainy days, I need to build a big starting fire to get the coke to ignite, and if it is foggy then sometimes it just won't start burning.
Very informative Dean, thank you. I think I might see if any blacksmith wants my coke and I will start digging a charcoal pit, Cheers Charlie
I’ve been down the charcoal route a couple of times and may go down it again. I’ve used a couple of direct burn methods as well as a retort but I ran across a method I’d never seen before the other day. Only uses one barrel, pretty close to smokeless, and leaves the charcoal pretty much intact. I might try it on a small scale to test it. Pete
I had been researching 'stockholm tar' (pine tar) for use on ropes, sort of the opposite thought: catch the volatile materials instead of feeding them to the 'afterburner'. Temps are not near as hot either.
Interesting you brought Stockholm and Finland up. (Sorry for the thread Jack Charlie. I'll stop after this I promise). It appears Honeywell and others are going big guns on biofuel production in similar fashion to good old fashioned pine tar production. Partnering with refineries in Finland among other places. Apparently they use their waste heat from refining to drive the pyrolysis process. Maybe the Finns really are sweeping their forests. Lol.https://www.google.com/search?q=hon...droid-verizon&sourceid=chrome-mobile&ie=UTF-8 Pete
Yes, sorry for the thread jack too Charlie. My mind drew associations with all of the steel drums and wood and clay and stuff in Pete's post. Interesting in that depending how one combines the wood and metal, one can end up with so many different results- from cooking over an open fire to distillation to blast furnace.
Don't mind at all chaps. I have located a good place for a pit in the garden and will start digging today, before the fire-season is upon us, Cheers Charlie
There are easier ways of making charcoal. I made about 400 gallons of it over 12 hrs by tossing in logs into a steel container (half of a house oil storage drum) and burning it. Piling up wood at a rate faster than it took to completely burn the wood. So the hot wood was out of reach of oxygen as it was slowly buried below more burning wood.
