lol yeah. bigger columns = bigger problems. That’s why so much focus is being put into cleaning it without disassembly. sooner or later though its definitely going to need to come apart
Standard order for something like this would be:
Detergent
Solvent
Acid
Detergent
Base
Detergent or solvent
Rinse x 3
Everything 55-65C except the solvent (obviously dependent on the solvent).
Still, visual inspection is necessary to validate any critical cleaning process. Can you get a boroscope in there?
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They tried the boroscope in every port they could. No success. I wasnt there personally tho. To my knowledge they are planning on putting a sight glass in but thats not exactly a small task.
Ive sugared up my column pretty bad in the past but a couple water flushes usually did the trick. Definitely nothing as bad as what they are experiencing.
Is stuff actually coming out visibly in the water washes, or is it running clean and you’re just inferring there might be more from the poor performance?
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I’m with the fellas thinking that damage is probably more likely than fouling if you’ve tried washing it a ton and haven’t seen any increase in performance. Do you have clearance to bring a gantry in to pull the wiper? Or at least lift it enough to get a scope in?
A little bit of both. Washes are definitely coming out off color although not super dark/cloudy. We think we have eliminated all of the other variables (short of damaged wiper blades) via redundant thermocouples and vacuum gauges.
Definitely can be done. Trying to exhaust all other options first though
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Hate to say it but if you had so much crud that 20 water washes hasn’t removed it, I can’t imagine it NOT having damaged the wipers.
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You need to change your crude prep sop. This should never happen again.
i warned them it wouldn’t be worth the hassle!
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Could be. But would damaged wipers really lead to such a significant drop in heat transfer. I get that the thin film wouldnt be as thin, but neither the main body heater or the internal condenser chiller had any problems maintaining temp
I’d think damage would explain a complete lack of transfer better than fouling. Unless it’s an inch thick (in which case, as @MagisterChemist said, your wiper is fucked anyways) you should still get some transfer.
Have you ruled out any other possibilities? Loss of prime in the heating jacket?
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Flow on both the MB and IC were verified. Temps for both were checked at 3 different locations using multiple devices. They also have multiple vacuum gauges which usually give pretty consistent results. They also verified the column was actually receiving material to distil (have a sight glass for that!)
We even checked the temp of the distillate that was coming off the IC as an additional means of verification
Sure it could. If they’re completely destroyed then the crude won’t “wipe” at all, it will just fall down in a streak down the side it’s input at. Then you’ll only get a fraction of the transfer
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Which would be consistent with Water washes still coming out a little dirty at number 20 too…
was really hoping it wasn’t the blades but this is the best explanation anyone has offered
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You’re going to need to open it up and confirm. And replace wiper assembly if it’s bad. You’re in for a bad time.
EDIT: and if the wipers were destroyed then the rinses probably never reached the places they needed to. You might need to manually scrub out the whole body.
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Depending on how much crud went thru and how solid it was it’s possible the evaporator is rifled now as well
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I got to see a spectacular case recently of a wiper destroying itself from a warped shaft. Basket and body both FUBARed