Explosion is one of the more serious accidents in gas-fired hot water boiler accidents. It will cause serious damage to equipment, heating systems and buildings, and it will cause great casualties and adversely affect social and economic development. Regarding the cause of the explosion of the gas hot water boiler, FANGKUAI Boiler summed up the following aspects and proposed an effective treatment method.
First, the cause of the explosion
1. Design and manufacturing problems
Unreasonable boiler design results in uneven distribution of flow in each water circulation loop. The thermal deviation is too large, and the structure has fillet welds, squares, flat plates, and steel materials that do not meet the requirements; the manufacturing process for manufacturing and repair is not good. If the welding quality is unqualified, the boiler will be broken.
2. Overpressure
The operating pressure of the boiler exceeds the permissible working pressure, and the compressive stress (internal pressure) of the steel plate increases, which exceeds the strength limit of the steel plate and causes cracking. The main reason is that the safety valve is malfunctioning, the pressure gauge is faulty, and the console meter indicates an error.
3. Overheating
The steel plate is overheated and burned, and the main cause is that the scale is too thick or there is grease or other debris in the pot water, which blocks the heated surface.
4. Corrosion
After the inner and outer surfaces of the steel plate are severely corroded, the thickness is reduced, and the strength of the steel plate is insufficient to cause cracking.
Second, the solution
1. The following measures should be taken for the defects in the design: first, the design is reasonable; second, the materials are strictly controlled; third, the correct manufacturing process specification and process card (including repair); fourth, the establishment of necessary rules and regulations; The fifth is to improve the quality and responsibility of operators and managers.
2. Strictly prevent overpressure. To ensure the sensitivity and reliability of the safety valve, automatic draining is required once a day. The problem should be dealt with in a timely manner, and a standard pressure gauge should be installed for comparison.
3. Prevent overheating. Effective water treatment equipment must be configured and strict rules and regulations must be established. The boiler should be free of scale or scale and no grease. When the boiler is out of service, check the scaling. If there is scale, it must be cleaned up in time.
4. Prevent internal corrosion. For larger capacity hot water boilers, thermal deaeration or chemical deaeration is used. In addition, check the internal and external corrosion conditions. Repair means such as replenishment or excavation according to the degree of corrosion (there must be a technical plan approved by the unit's chief engineer and reported to the local boiler supervision department).
5. In order to prevent boiler explosion, the boiler should be inspected regularly. At the same time, the boiler management department must formulate effective measures. The operators and management personnel must strictly implement the safety code for stopping the boiler after minor accidents.