Steam boilers are integral for the processing operations in the manufacturing industries. Plant managers follow several guidelines and practices to ensure that the boiler system is operating without any issue. Boiler problems such as corrosion, carryover, scaling, etc., are usually inevitable and require immediate action when detected. However, in case of boiler issues like overheating, prevention is better than cure. Boiler overheating is a serious boiler problem that may cause severe damage to the process plant and the operating personnel by putting them at the risk of explosion. Although advanced boilers are equipped with safety fittings to ensure locking the component before the boiler overheats, it is prudent to be aware of boiler overheating and its signs to prevent it.
What is Boiler Overheating?
Boiler overheating is caused by the failure of the safety equipment. Steam boilers overheat when hot water transported to the central heating system is hindered from circulating. It is usually due to pump failure or blockage in the system. The failure of safety controls maintaining the temperature, pressure, gas, and water supply lead to boiler overheating. In some cases, it may result in a condition termed ‘runaway boiler’ that is hazardous to both the plant and the operating team.
As the boiler system overheats, the internal components of the boiler face immense stress. It causes irreparable damage or, in severe cases, boiler explosion. With the boiler overheating, the components may melt and release toxic smoke in the vicinity. Nowadays, advanced steam boilers with automation control lock the units to prevent overheating and display an error message to notify the plant managers.
Causes of Boiler Overheating:
If the boiler overheating is not prevented at early detection, it may cause tremendous harm to the surroundings and the people. Common causes of boiler overheating are as follows,
- Limescale Build-up
- Blockage in the system
- Faulty pump
- Faulty thermistor
Limescale Build-up:
Limescale build-up on the heat exchangers hinders the water flow that leads to boiler overheating. The purpose of a heat exchanger is to heat the water before circulating it for the combustion process. Limescale build-up is also known as kittling as it produces a kettle’s whistle sound.
Blockage in the system:
Blockage in the steam boiler is indicated by strange noises emitting from the system. Radiator not heating properly is another sign of a blockage in the boiler system. It is generally cleaned by a power flush process that eliminates the limescale, rust, and other impurities to allow the seamless circulation of hot water.
Faulty pump:
The purpose of the pump is to circulate the water in the steam boiler system. If the pump fails to operate, the hot water fails to leave the steam boiler system, resulting in boiler overheating. The pumps are repaired by an engineer, but usually, they need to be replaced.
Faulty thermistor:
The thermistor monitors the water temperature to determine the requirement to increase or decrease the temperature as per the demand. As the thermistor fails, it leads to water temperature getting too high. It consequently results in boiler overheating.
Prevention for Boiler Overheating:
It is prudent to prevent boilers overheating rather than repairing the aftermath. Boiler overheating can be prevented by,
- Fitting a magnetic filter to collect debris and rust from the heating system before it builds-up and forms a blockage. The build-up of debris is one of the common causes of various boiler issues that should be avoided.
- Installing a scale reducer decreases the amount of limescale formation in hard water. Reduced limescale ensures that the steam boiler system is free of hindrance in water flow that may cause boiler overheating.
- Do not supply the steam boiler with cool water when the system is overheated. It results in the boiler flashing into steam as it is introduced to the hot components of the steam boiler, causing a tremendous and immediate rise in pressure. It can lead to boiler explosion or rupture of components.
- Avoid constant flow of gases in the steam boiler as it causes rapid increase of temperature and pressure, leading to a runaway boiler.
- Reparation of steam boilers by an inexperienced engineer leads to issues like wiring errors, manual opening of gas valves that leads to a constant flow of gas, removing pressure relief valves while repairing boiler leakage and neglecting to fit it back that prevents the boiler system from facing excess pressure. It consequently leads to boiler overheating.
Conclusion:
Rakhoh Boilers, with their 38+ years of expertise in steam boiler manufacturing and thermal solutions, have been serving over 20 process industries globally. We manufacture an efficient and reliable range of industrial steam boilers, waste heat recovery systems, thermic fluid heaters, and boiler accessories. We provide the best boiler services like steam trap assessment, boiler automation, energy audit, annual maintenance contract, etc., to boost the efficiency and productivity of the steam boilers.
To know more about our products and services, visit www.rakhoh.com