Question 423Steam Plants - Assistant Engineer

The correct answer is B) Steam drum surface blow. The steam drum surface blow is the correct method to blow down a boiler without securing the fires. This is because the steam drum surface blow allows the operator to release steam and water from the top of the steam drum, which helps remove accumulated solids and sludge without disrupting the combustion process in the furnace. In contrast, the other options (bottom blow, front water wall header blow, and rear water wall header blow) would disrupt the fire and water circulation within the boiler, which is not recommended when the boiler is still in operation.