Water Carry Over In Smoke Tube Boiler (Fire Tube Boiler)

Reduce your capacity to 13.5 tn.

File #9 in the list has several case studies that might help you identify the problem....

http://www.venus-boiler.com/technical_papers.php?paper_id=160%E2%80%8E

To be sure, you are saying, "the steam quality has decreased over time?" Steam Space is intact ? The manufacture may offer a solution to achieve satisfactory results, after a complete check of the internals.

(1)Check your water level it may be to high.

(2)The boiler may be under sized to the factory demanded.

(3)What would be your stack tempreture before the evaporation rate reaches the 13.5 tn and after this should give you a good idea on the rating.

Use a moisture separater to capture the carryover.

...in the first header tank.

I would perform an internal inspection if the unit is not scaled up and the fire tubes are clean.

When restarting watch the gauge glass and make sure the water level is normal. A problem with the fuel train not being sized properly will cause the load to swing. Letting pressure drop and then firing at maximum rate this will cause the water level to raise which allows carry over.

I think the fuel train is causing the boiler to swing. You may have to observe the boiler when what is happening watching the water level closely.

I had a plant where the gas pressure varied. They switched to oil and the problem went away. At this point they fixed a pressure regulator.

Simple. Blow the boiler down, in the manner it says in the user manual, and top-up with fresh feedwater. The total dissolved solids in the boiler water has risen recently above that point where carry-over starts and the contents of the boiler must be reduced in mineral content.

Google "boiler priming" for more information.

Fire-Tube Boiler is a package steam generating system, factory assembled and tested. It consists of boiler pressure vessel, combustion and water feeding equipment and controls, all coordinated to form an integrated design unsurpassed for safe, quiet and dependable steam generation.Combustion equipment firing modes are available for on/off, high/low or full modulation operation, the combustion system is also available for alternate or multiple fuels firing such as light oil, heavy oil and gas.