I think I read somewhere that the first diesel was originally intended to run on coal dust. The only problem was finding a suitable method of carburation :-) Apparently, they'll run on anything flammable, if you can get it into the combustion chamber regularly. I doubt it's that simple, of course.
or is there something about it that prevents that?
it does, but that doesn't mean it will operate ideally or even practically usably.
cotton wick is used in candles
Wrong wick size or wick trimmed too short. Or an irregular candle shape that can't practically be wicked correctly.
NT
Carburation of dust is possible. But abrasive particles would be a problem.
NT
My old company had a project for wet-grinding coal to make a high-solids slurry that was used to fuel a diesel engine. The exhaust was rather smoky and the project wasn't pursued, but I do remember the chemical engineering lab being absolutely filthy for the duration of the project.
Who was that then?
In those days it was the Cornish china clay company English China Clays (think of the conical white sand-tips around St. Austell). You might ask what a clay-mining company was doing grinding coal, but they had particular expertise at fine-grinding white minerals, e.g. kaolin and marble, for the paper industry amongst others. The grinding process is known as sand-grinding or sand-milling. It's a wet milling process, equivalent to ball-milling but on a finer scale, using sand as the grinding medium rather than steel or ceramic balls, and using a stirred pot rather than a rotating drum. The mills were quite large (and noisy). In a two-stage process, centimetre-sized marble lumps would be reduced to a particle size 100% finer than 5 microns (0.005mm) at a rate of several tonnes per hour.
The company was always looking for other applications for its various expertises, and grinding coal to similar particle sizes to the above was one area they looked at. I think their conclusion was that such fine grinding wasn't really necessary, and other technologies, cheaper and widely used elsewhere, were just as good for what was wanted, so there'd be no money in it.
How interesting! I was always slightly amazed how fine you can make the "pulverised fuel" used in conventional coal fired power stations, given that this is milled (dry) in ball or roller mills with rolling elements a foot or so in diameter.
Mind you the *first* station I visited (Kingston on Thames) still had chain grate boilers.
Many years ago I visited a cement works at Beeding, in the Adur valley, just to the east of Lancing, Sussex, now long closed and derelict. See pic here
I vaguely remember seeing a picture of a very early diesel type machine tha t had a chamber housing the burning fuel. I am not sure how the equivalent of the firing stroke took place; just allowing air in on the downcycle I be lieve. So it would have been a two stroke designed on the steam engine pri nciple in the days when waste oil from cotton seed was being considered for something better than agricultural waste.
Come to think of it it is more or less what Frank Whittle designed all over again 100 years later. Efficiency was not a consideration compared to pote ntial and availability.
Needlessly complex engineering had yet to be thought of, as had light weigh t engines for motor transport smaller than ships. Up to then "small" had on ly been desirable for enabling a team of horses to deliver it.
We really have no idea what went on in the dark ages before petrol.
Actually some of us have a very very good idea.
You only have to visit Eastern European countries to see how transport is still by horse and of course coal fired steam engines were all the rage, and indeed have a renaissance in the field of transport.
Why doesn't that surprise me?
Ah:
The point being exactly mine; one of practicality and availability. I am pretty sure that if he had not been hamstrung by the pre-world war two military complacency/lack of interest and investment, Whittle might have investigated bunker oil for his jet.
In fact I have no idea why he worked with paraffin.
Exactly. You have no idea.
There are of course sound engineering chemical and physical reasons why he did, but you don't know them.
Given the need to heat bunker oil in order to pump it around, some of the reasons not to use it in an aeroplane engine seem (to me) patently obvious.
m pretty sure that if he had not been hamstrung by the pre-world war two mi litary complacency/lack of interest and investment, Whittle might have inve stigated bunker oil for his jet.
Who told you that?
m pretty sure that if he had not been hamstrung by the pre-world war two mi litary complacency/lack of interest and investment, Whittle might have inve stigated bunker oil for his jet.
The need to cool certain parts of the engine was a problem at the time but of course, you didn't know that.
Clearly you don't either:
"Whittle initially used petrol as fuel, before changing to paraffin"
And you still don't.
...for sound engineering chemical and physical reasons
dick
Have something to add? Share your thoughts — no account required.
Ask the community — no account required