In our shops we had good clean and dry air for plasma cutters. Certainly nothing like what we fabbed up for a pharmaceutical company to dry pills. That engineer rattled off something like "minus 50 degree C dewpoint, 0.05 micron filter.........".
Plasma cutter - desirable features
- Thread starter Paul Allwood
- Start date
Paul Allwood
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Equipment
Kubota B7200HSTD, RC60-72H MMM, homemade FEL, forks & ballast box, rotary hoe
This was one of those projects prior to my move into the home base to manage the shops. The last years I spent in the field were on projects that were smaller than the multi-million, often multi-year projects that were the main pursuit of the company. I enjoyed challenges and working on odd things. When something came in that needed some "sorting out" it was mine. I usually had a few of these going and it was fun.
An engineer from one of the pharmaceutical plants we did work for called one day to ask If we could run an air line. Sounded simple enough to be done by their maintenance department but OK. He said he'd like to sit down for a discussion first. Really, how difficult could it be? We went for a walk that I thought would be to get eyes on the location. Instead we went to the cafeteria and got coffee. Then we sat down and he literally made rough sketches on a napkin while rattling off numbers as I took notes.
They were having trouble with the coating on new pills they were making. The coating was cracking as it dried and he blamed the problem on the pills retaining moisture from the manufacturing process. Their solution was to make the pills really dry. So off we went with the air properties already mentioned and "we'll need to make some trees from clear PVC that can be assembled and disassembled through the access hole in the bins of pills - let's do six stations - we'll need strip chart recorders for moisture, temperature, ect - the controls need to know when we hit the target numbers we're looking for to signal each bin is done - we'll need a stainless panel to house the strip chart recorders, valves, etc. - and on it went.
I had worked with a really good controls outfit on another project and contacted them. They said they'd like to be involved, so they engineered the setup. Our shop built it. We also made several dozen "trees" from clear PVC. There were all sorts of hurdles we had to clear, down to the solvent cement used on the PVC. We then installed the system and got it up and running. Next came a long period of silence. When a pharmaceutical company does any kind of new procedure there's a lot of testing and validation, so it wasn't surprising. Months later I met with a different engineer there on another project and asked how things were going with the pill drying system. He said it was a failure. First thought was why would they want me back for another project following a disaster I was involved in? Then he explained that while the system worked as intended, testing the finished product revealed the coating didn't dissolve as it should have. Part of that next project included destroying the drying system.