Question 477Steam Plants - Assistant Engineer

The correct answer is B) check for high water level in the drum. A sudden drop in the outlet temperature of an uncontrolled superheater indicates a problem with the steam generation process, which is often caused by a high water level in the boiler drum. When the water level is too high, it can lead to carryover of water into the superheater, causing a rapid drop in the superheater outlet temperature. Therefore, the appropriate action is to check the boiler drum water level and make necessary adjustments to maintain the proper water level. The other options are not the correct responses in this situation. Increasing the firing rate (A) or reducing the forced draft fan speed (D) would not address the root cause of the problem, which is the high water level. Bypassing the air heater (C) is also not the appropriate action to take in response to a sudden drop in superheater outlet temperature.