Boiler Over Fire

Boiler front and rear of burner type already have over fire protection device to protect boiler tubes overheat. The protection devices are furnace temperature which detected by thermoprobes at nose area and limitation of saturation temperature gradient but over fire still potential happen.

If we look at boiler tangential type, there have another protection device like ratio of super-heater and re-heater flow and ratio of fuel flow and steam flow.

Before we assume that the boiler tubes got overheat, we must take a sample of the tubes as first picture above and make comparison with picture below as a theory of boiler tubes overheat.

Other information for boiler over fire protection (or re-heater tubes protection) with tangential firing burner type can be see on this http://idpowerstation.blogspot.com/2009/06/re-heater-protection.html .

That mentioned "boiler during start-up can be found by calculation ratio R/H and S/H should be higher than 80% and over firing process from different fuel flow and steam flow more than 13%". We did start boiler which result Main steam flow 9T/h and Fuel mass flow 37 T/h. That fuel mass flow was different 75% than main steam flow (more than 13%.)

It means boiler over fire protection on tangential firing burner type can be application on boiler front and rear burner type.