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Posted by realthang05 on July 23, 2008 at 02:54:43:
In Reply to: Start up procedure 4 Superheated Water Tube Boiler posted by Chuck on July 18, 2008 at 00:55:36:
: Hello Everyone,
: I'm studying for the Los Angeles City Steam Engineers License exam. The plant I work at only has Fire Tube Boilers. I need to be familiar with the Water Tube Boilers to ensure that I pass the oral examination. Last time the examiner asked me to start a 2000 bhp superheated water tube boiler.
: So please, if any of you have a start up procedure or SOP or anything that resembles a start up procedure for a superheated water tube boiler, I'd appreciate it very much. I've been searching the web for weeks now and just found out about this boiler forum. The procedures in the textbooks I've read are pretty lame.
: Again, thank you for your help,
: Chuck
: Sail Fast, Live Slow
Start up a boiler and put it on line. Including steps for NRV and Stop vlv.
1. Check the boiler over to insure that all the manholes, handholes, and water column connections are in place. Make sure the pressure gage is open and the steam drum vent is open. Make sure the drains are closed and the safety valves are not gagged.
2. Slowly fill the boiler up to 3” in the glass.
3. Purge the firebox with at least 5 minutes with an air flow of not less than 50 percent of that required for full load.
4. Light off the center most burner according to the manufacturers recommendations. You could have an automatic combustion control firing gas or oil. The burners could be manual operation. Maintain a low fire so that the boiler warms up slowly.
5. When the boiler pressure is approximately 5 psig you can do the following:
A. Open the drain between the main stop and the non return valves. Open the bypass around the main stop to warm up the header back to the boiler and to remove condensate.
B. Close the bypass
C. Crack open the non return valve and blow through the drain to remove condensate from the boiler side of the line and to warm up the section of line from the boiler. Close the non return valve.
D. Close the drain between the main stop and non return and open the bypass around the main stop to equalize the pressure across the main stop valve. Open the main stop and close the bypass.
E. Open the non return valve. (Raise the stem)
6. When the boiler pressure reaches 10-20 psig, close the steam drum vent.
Remember, if the boiler is equipped with a superheater you must always keep the superheater vent open during startup until the boiler cuts itself on line. Failure to do so could result in burning up the superheater. Never let the superheater temperature go above 700 degrees.
When conditions permit put your firing controls and feedwater regulator in automatic. Always be alert for anything that could go wrong.
This is what I was taught for a general startup procedure and what we use for the City of Detroit when we send operators down.