The causes of self-suction burner flameout may be as follows:

 Low gas pressure: If the gas pressure is insufficient, it will lead to incomplete combustion, resulting in flameout.

Low combustion air pressure: Insufficient combustion air can reduce combustion efficiency, leading to unstable flames or even flameout.

 Low instrument air pressure: Insufficient instrument air pressure can disrupt the burner's normal operation, causing flameout.

Fan failure: A faulty fan can result in insufficient combustion air supply, affecting combustion and potentially causing flameout.

The burner is designed for a much higher load than the actual combustion load: If the burner is designed for a much higher load than the actual load, it can lead to incomplete combustion, resulting in flameout.

High air-fuel ratio (excessive combustion air): An excessively high air-fuel ratio can result in a very short flame, with the base of the flame clearly disconnected from the burner, making it prone to being blown away from the burner and causing flameout.

Significant fluctuations in gas composition: Fluctuations in gas composition can affect combustion stability, leading to flameout.

 Low furnace external atmospheric pressure: Low furnace external atmospheric pressure can affect the negative pressure inside the furnace, impacting combustion and potentially causing flameout.

In addition, the improper ratio of primary and secondary air can also lead to flameout:

Excessive primary air ratio: The flame is too short, and the burner root is significantly disconnected from the burner, which can cause the flame to be blown away and result in an extinguishing event.

Insufficient secondary air ratio: A low excess air coefficient results in high combustion efficiency and a high gas concentration, leading to a slow flame propagation speed. If the flame propagation speed is slower than the injection speed of the mixed combustion gas, the flame can be blown away from the burner, causing an extinguishing event.

Excess secondary air ratio: When the furnace's thermal efficiency decreases and the furnace negative pressure becomes too high, the air leakage increases, reducing combustion efficiency.

Conversely, if the furnace negative pressure is too low, the air flow rate in the mixed combustion gas decreases, slowing down the flame propagation speed and potentially causing an extinguishing event.

These factors can all lead to inconsistencies between the flow rate of the mixed combustion gas and the flame propagation speed, ultimately resulting in an extinguishing event.