Shenhai Explosion-Proof
In explosive atmospheres, the combustion modes of combustible gases are crucial to understand. These include constant-pressure combustion, constant-volume combustion, deflagration, and detonation.
1. Constant-Pressure Combustion:
This mode occurs in open settings where combustion products can dissipate, maintaining equilibrium with the ambient pressure. It’s a stable process, free from pressure waves, characterized by a specific speed of combustion that depends on fuel delivery and reaction rates.
2. Constant-Volume Explosion:
Occurring within a rigid container, this ideal combustion often starts locally and spreads. In such a scenario, explosion parameters differ, necessitating a constant-volume approach. Typically, the explosion pressure can be 7-9 times the initial pressure for hydrocarbon gas-air mixtures.
3. Deflagration:
Involves gradual flame acceleration due to confinement or disturbance, leading to a pressure wave. Different from constant-pressure combustion, the pressure wave and flame front move subsonically. It’s a common phenomenon in industrial explosions, often exhibiting a complex wave and zone structure.
4. Detonation:
The most intense form of gas explosion, marked by a supersonic reactive shock wave. For hydrocarbon gas-air mixtures, detonation speeds and pressures can be significantly high.
Understanding these modes is vital for preventing explosions. Deflagration, in particular, can weaken or intensify into a detonation under certain conditions, so mitigating factors that could accelerate flame propagation is crucial.