May 14, 2010
Originally published October 22, 2002
This story will make little sense to anyone who doesn't work in a chemical plant around all sorts of really neat operating equipment, but I saw something today that I had never seen before. We had a massive, disasterous plug-up of wet slurry in a thing called a "dryer." Obviously, even for the uninitated, a "dryer" is not supposed to produce fricking MUD. A dryer is supposed to DRY pigment, not make mud. This one made MUD today.
I checked all the obvious things first, and I could find nothing wrong. So, I had to put on my thinking cap. After talking to the operator and checking the trends on the DCS, I knew what had happened and I knew how to fix it. We ended up putting about five tons of wet pigment on the ground to unplug everything. Meanwhile, an electrician replaced the burnt thermal-coupling that told my brilliant computer-controlled system to do exactly what it did.
Anybody who believes that computers are "smart" should work around computers that control process equipment. A computer will believe a reading of vacuum on a 600# steam header, it will believe reverse-flow in a pressurized system and it will damn surely suck on a bogus temperature reading. That's why we still pay human operators to watch this shit.
Computers a great when they work. But they are merciless bastards when they become confused.
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