I worked on a system once upon a time that fed steel balls into a ball mill. We tested it thoroughly in the workshop with the same steel balls used on the customer's site, but when we went to commission it, it jammed non-stop.
Turns out a hundred randomly selected balls won't contain most of the outliers that you'd get in even one tonne of balls, and when you're feeding 5 tonnes per hour, that's a lot of jams. We had balls with big craters in them, half-balls, balls with two halves offset by 50%, and everything in between. Not the kind of thing you could rely on rolling nicely.
Also, of course, when you ask a mill ball manufacturer for a sample, they might be inclined to send you the very nicest examples they can find, because they think you might buy their product...
Anyway, unless you're super careful about sourcing legitimate feed samples it's easy to think you're testing against the real product when you really aren't.
What comes out of a steel ball mill? And why is steel made into (misshapen) balls before this process?
A ball mill is used to grind things into paste, usually for further processing. In this specific case it was a SAG mill (https://www.mogroup.com/portfolio/sag-mills/) and it was frikkin' huge, powered by a 10MW electric motor. It ground up ore-containing rocks from a mine which were then processed to produce lead and zinc. The balls roll around in the mill and help to grind up the ore, which I guess works better if they're round, which they will be before long due to wear and tear no matter what shape they go in. They come out as tiny ball bearings. It was quite an interesting project!
It sounds like their scaled up plant accepted a wide variety of materials, but this one specific input stream slowed them down.
So they weren't shut down while they figured this out, they just processed the material they knew they could process until they had a solution here.
Since encountering the differences, we tracked down the rarer corn growers in California and now use corn stover for testing as well.
Agriculture is the intersection of industrial mechanization and biological systems. Unlike traditional manufacturing, flexibility and efficiency is learned over time as situations are encountered that exceed previously theorized boundaries/ranges.
I have a grower who used gigantic wood burners for heat instead of natural gas. When I walked through his boiler room I noticed a wheelbarrow full of nails and other fasteners. He said 90% of his labour and headaches with that system were dealing with steel chunks in the feed stream, something they barely accounted for beyond adding a magnet when they built the system. Not everything can be planned for in advance.
Disconnected data is just information, not knowledge.
To be honest, to me it sounds like a dream job.
This is like the joke about the drunk looking for his car keys under the street light because the light is better than whete he dropped them.
“I believe he did, Bob.”
What do you think the article was about?
Ordinarily, I do not reply to these kind of comments, but this article is receiving a lot of them along these lines. The comment breaks down to "Why did you not predict everything that could possibly go wrong before you started this new tech project?"
I hope that it is clear that it would be impossible to identify every problem before field testing. Even in commercial manufacturing, you will run up against novel problems and have to engineer a solution onsite, even though we have had factories for about 250 years.
When they start testing in a different state or country, they will discover a new crop that breaks their system and will go though this process once again. But now, they are more experienced, and it will probably be easier.
Scaling up means testing with new inputs at scale. So now they've done that?
It seems to me that with “endless free money” we miss things like “this one input stream will be a nightmare, let’s not do it”.
We delivered 90% of permanent carbon removals globally last year: https://twitter.com/charmindustrial/status/14511691760646430...
https://www.bioenergy-news.com/news/frontline-bioenergys-iow... https://www.news.iastate.edu/news/2016/12/20/rapid
This is especially the case in high-risk unproven areas such as cleantech where the solution space is vast and potential problem areas significant. Any problem area can kill a project, so why are we progressing so fast to build first?