Completely premixed burners have poor flame stability, especially the possibility of backfire, so the adjustment range is small. In order to ensure stable combustion, the calorific value and density of gas are required to be stable. To prevent backfire, the head structure is relatively complex and bulky. Since the gas and air are fully premixed, the flow rate at the fire hole outlet increases significantly, resulting in loud noise, especially at high loads.
Mainly used in industrial heating devices
1) Diffusion combustion
Diffusion burner: stable combustion, no backfire: simple structure, easy to ignite, easy to adjust; long flame; prone to incomplete combustion, or even black smoke, must be supplied with more excess air.
2) Partially premixed combustion
The premixed gas-air mixture is ready to burn as soon as it exits, while the remaining gas needs to be burned by diffusion mixing with the surrounding air. Partially premixed burner: short flame, strong firepower, high combustion temperature, relatively complete combustion, relatively high combustion efficiency, easy adjustment, flame stability is not as good as that of diffusion burner, although the flame hole thermal intensity combustion temperature is higher than that of natural induced air diffusion Type burners are taller but still limited.
3) Completely premixed combustion
Completely premixed burner: The flame is extremely short and does not emit light, the flame spreads very quickly, the flame stability is poor, backfire is prone to occur, there is little excess air, the combustion temperature is high, and the noise is loud.