Steam boilers are an integral asset in any manufacturing and processing unit. While investing in steam boilers, plant managers ensure that the boiler promises efficiency, reliability, optimal combustion, and steam quality. It is essential to regularly check and maintain the wear and tear of boilers, failing which, may lead to a boiler explosion. Steam boilers, if left unchecked, are potential bomb that cause severe damage to the process plant and operating team. Although the boiler explosion rate is rare compared to boiler installations annually worldwide, it does not entirely eliminate the possibility of boiler explosion.
What is Boiler Explosion?
Boiler explosions are destructive failures of steam boilers. There are two primary reasons that commonly cause boiler explosions. One of them is the failure of pressure parts of the steam and waterside. Such failures are caused by corrosion of vital parts, failure of safety valves, or low water levels. The second-most common cause of boiler explosion is caused due to fuel/air explosion that takes place in the furnace. It is also sometimes termed a firebox explosion. Such explosions in solid-fuel boilers are rare; however, an explosion in oil-fired boilers and gas-fired boilers lead to damaging consequences.
Causes of Boiler Explosions:
As discussed above, boiler explosions mainly occur due to either pressure vessel failure or fuel combustion explosion. Let us understand some of the causes of explosion in detail:
Failure of Pressure Vessel:
Pressure vessel failure is usually caused by rusting or overheating of metal by low water levels or excess scale formation. The vessel is also impacted by damaged safety valves or water hammer. It occurs when the pressure range of the vessel is affected. To understand it better, the pressure change in the steam boiler operating at 100 PSIG can expand the water 1500 times than its original volume. Consequently, it leads to a substantial force that causes hazardous boiler explosions.
Fuel Combustion Explosion:
Fuel combustion explosions often take place due to failure in burners. Ignition failure, improper gas lines, or loose valves leads to combustion gas buildup in the high-temperature vessel. It results in boiler explosion along with leakage of gases throughout the process plant. An initial explosion can cause rupturing of pressure vessels, resulting in a second explosion that is tremendously hazardous.
Steam Pressure:
Usually, in a steam boiler, water is heated to produce steam that is stored in the boiler chamber. The steam is under immense pressure that requires precise operating methods to prevent boiler explosion. Operating personnel neglecting the proper guidelines and regular maintenance cause the risk of boiler explosion. As steam pressure exceeds the boiler design, it results in a hazardous explosion that severely harms the vicinity and the safety of the operating team.
Scaling or Corrosion:
The presence of oxygen in feedwater or hot water leads to scale formation and corrosion in steam boilers. It results in damaging the metal of the boiler and eventually boiler explosion if left overlooked. If neglected, corrosion and scaling cause weakening of boiler metal and the welds that seal the tank.
Precautions to Prevent Boiler Explosion:
Negligence in management is the primary cause of boiler explosion that can be prevented by following some safety guidelines mentioned below:
- Inspection of pump inlets and loose connections
- Installation of ash removal system to avoid ash accumulation in the furnace or other equipment
- Pump priming
- Regular checking of safety valves
- The boiler should be operated as per its design pressure
- Treatment of water before feeding it to boiler
- Ensure that the boiler vents function properly
- Regular inspection for leakages of water, gases, steam, and air
- Ensure proper insulation of heated parts of boilers
- Maintenance of Forced Draft Fan and Induced Draft Fan
- Regular checking of Pressure Gauge
- Regular cleaning of accessible boiler parts
- Cleaning of boiler tubes to prevent ash accumulation or scale formation
- Maintaining the primary and secondary air ratio as per fuel feeding
- Scheduled checking of burner operation, back pressure, and line pressure to avoid thermal stress
- Follow boiler manual and standard guidelines for safety
- Periodic maintenance of steam boiler and boiler accessories
- Proper training of operating personnel on appropriate methods of operation
- In serious issues, ask for the guidance of the boiler manufacturer
Boiler explosions, though undoubtedly hazardous, can be avoided by proper operation practices and regular maintenance of steam boilers. Rakhoh Boilers, with their expertise and experience in thermal engineering for over 38+ years, offer a comprehensive solution for industrial steam boilers. We manufacture a range of world-class quality products such as steam boilers, waste heat recovery boilers, thermic fluid heaters, and boiler accessories. We also provide excellent boiler services like energy audit, steam trap assessment, boiler automation, annual maintenance contract, etc.
To learn more about our products and services, visit www.rakhoh.com