Unbelievable Steam Velocity Question

Grey_Hair

Low pressure steel fire tube steam boiler has 2,000,000 btu's input - operating at 9 PSI

This Boiler has 1 - 4" steam outlet, I figure this would give a steam velocity of 123 ft/s, does this sound like the correct calculation ? ? Is 50 ft/s the magic number to try and acheive ?

Customer claims they have severe condensate carry over which floods the main steam header and heat exchangers, and have not been able to heat building (approx 40,000 sq ft) properly for decades. (No kidding)

Side Note: This is crazy, but there is no equalizer piping from the steam header back to the Boiler return. The end of the main Steam header where any steam guy would typically put a full size 90 elbow pointing down is a cap.

STEAM DOCTOR

Oh boy have you got problems. Of course you have condensate carry over if there is no way for the condensate to exit the header and return to the boiler. And of course high pressure and high velocity ain't doing you too much good. Pics pics pics

ethicalpaul

Wow, it should have what, like twin 6" supplies into an 8" header with a 4" equalizer right?

Even if the equalizer were added the velocity would be ridiculous, I'd expect carryover to the main regardless of the presence of the equalizer but it would at least be improved. Looking forward to hearing the resolution of this one, good luck!

Jamie Hall

That's a nice breeze in that pipe — but in and of itself it's not a problem, assuming the head loss isn't too much. What is a problem is that it will surely carry a small deluge of water dropllets.

Can you post a picture of the steam header and any riser or anthing? You are going to need some arrangement so that the steam in the header is forced to take a 90 turn up — or at least not more than 45 off the vertical — while another pipe — same size or eccentric reducer flat on the bottom — continues on and then drops down to a cold return — Hartfrod Loop or whatever. Even better wold be to route the steam into a dryer drum — say 13 inch diameter maybe, 3 or 4 feet long — from the bottom at one end, and take the steam off the top at the other and a condensate/carryover line from the bottom at that end — but that may involve much too much new piping to be worth it.