The water level of steam drum can reflect the condition between feedwater quantity and evaporation quantity of boiler. If the two parameters maintain a stable balance, the water level also remains unchanged; otherwise, the water level will rise or fall. Besides, there is also a false water level phenomenon. How do we understand the false water level?
An Interlock in the boiler’s control system is a programmed or hardwired condition that forces a device to be in a pre-determined or permissive state before the process can continue.
Depending on design pressure, fuel type, either liquid, gas or solid, all steam boiler require interlocks to sequence the operation and to prevent damage to the boiler. Examples of such devices are High or Low Boiler Drum Water Level, Low Boiler Feed Pump Pressure, High or Low Fuel pressure, High or Low Atomization pressure (oil fired), Proof of Ignition, Proof of Flame, FD and/or ID (solid fuel) Fan Motor Operation or combustion air pressure, Damper or Valve position and High Boiler Steam Pressure as well as O2 and furnace temperature.
When they reach a certain size, industrial steam boilers are installed in a boiler room which is necessary to ensure safety while they are operating as pressure equipment, in accordance with local regulations.
If the boiler gives overpressure indicator which affects boiler's safe operation, depressurization measures should be taken. However, please pay attention that depressurization can not be too fast. After the overpressure problem of steam boiler is solved, we should check the internal and external parts of boiler to ensure that everything is going well.
A water level sensor fail on a steam boiler is extremely dangerous. The low water cut of should be tested daily. If the sensor fails the boiler could turn all the water into steam, leaving the boiler dry. Without water in the boiler the flame from the burner would heat up the heating surface to extreme temperatures and would crack and damage the inside of the boiler. But that’s not the dangerous part. If water added to boiler while it is extremely hot. Once water touches the extremely hot heating service, water would immediately start to evaporate into steam. When water evaporates it expands 18x it’s original size. The boiler would explode from the sudden increase in pressure from the inside. Some in some cases, boilers that have exploded out of a building and have landed 100s of feet away.
There are many opinions on the best way to clean a steam boiler. One of the oldest ways is to dissolve a pound of tri-sodium phosphate (TSP) and a pound of caustic soda (lye) in water and pour it into the boiler. Let it cook for a few hours and then drain the boiler. If you can't buy TSP in your town, try a commercial soap called MEX. It works well and will not damage the rubber gaskets found in some boilers. However, before you clean any boiler, check the manufacturer's instructions for their recommendations.
