Opinions on how this foam spill happened?? 1

[ContractorDave]

We have a diverse group of people here and perhaps someone can help with an investigation. Attached are the details of a foam spill from a horizontal bladder tank. Any notions on exactly what might have happened would be greatly appreciated.

 

[ContractorDave]

Just a note: we lost approximately 2200 gallons of 3% Flouroprotein.

 

[KiwiMace]

Could the overnight contraction of the foam in the overflow line have started off the siphon?
The bladder will crush down onto the perforated pipe preventing the siphon from being broken when much of the tank contents are already discharged.
A vented tank would air lock in this same situation.

 

[ContractorDave]

Thx KiwiMace

Since the tank / bladder was presumably overfilled and waiting to discharge the foam bubbles at the top of the bag before it discharged product, I assume that this was what precipitated the event. Why it continued is what puzzles me. It would seem rather unlikely that the bladder would be so flexible as to cover the perforations on the siphon tube the way it appears to be designed, but I have not seen the actual piping for myself, just the manufacturers drawing as you see it in the attached pdf. Perhaps you are right. I am awaiting a response from the manufacturer also.

Thx again

 

[KiwiMace]

The bladder didn't have to block the holes. It only had to prevent air from getting sucked in, which of course it is designed to do.

When the bladder folded and creased and stopped contracting, the siphoning foam would stop.

 

[ContractorDave]

And now that you've pointed it out, how obvious it is. Nobody else we've talked to seems to have caught this, and the manufacturer has been unresponsive. Thx very much.