industrial campus steam problems

Steamhead (in transit)

it has to go somewhere, if not the pressure will rise and blow the safety. First thing I'd do is check the connected load against the boilers' capacity. If that's not the problem, see if any parts of the system are not getting steam, and find out why.

Chuck_19

I have two 125 psi, 100,000 #/hr steam boilers. Each boiler has an 8" dishcarge pipe that tee's into a 12" header, the 12" HPS header is 50' in length and tee's into a 16" HPS main that runs through the plant. Everything runs fine with one boiler operating but when the second one comes one the relief, set at 175 psi, blows and we cant get full capacity out of each. any ideas on the problem or solutions?

bob_50

Call your

control contractor.

Tony Conner_2

Multiple Boilers...

...firing to maintain a header pressure will have the drum pressures drift up as they get loaded-up. On high-fire, the drum pressure should hit something like 140 - 145 PSIG. The header should stay at 125. There is normally a pressure transmitter on the header (the 12" header, not the 16"), that controls the burners. This is often only rigged to control one boiler at time though, and in cases like that, one boiler is set on "auto" and it takes the load swings, and other boiler(s) stay on hand-fire as base load.

I'd try running both boilers on manual at the same time (just temporarily), and see if you can make the plant work that way. If things behave, that means things are OK, mechanically, and it's likely a control problem. Where are the high pressure trips on the boilers set?

And that 12" header is none too big for this load and pressure, by the way. The pressure transmitter is on the 12", and not on the 16", right?