Safety system of oil and gas boiler burner

If a large amount of combustible gas accumulates in the oil and gas boiler (such as gas leakage or fuel oil evaporating into oil and gas in the high-temperature furnace) and reaches the explosion limit, it will cause deflagration during combustion, posing a serious threat to the safe operation of the oil and gas boiler.

The so-called explosion limit refers to the concentration (generally volume concentration) range at which high-speed combustion can occur when gas or fuel oil vapor is mixed with air and encounters a fire source. The lowest value of this range is called the lower explosion limit, and the highest value is called the upper explosion limit. Under normal circumstances, the explosion limit of natural gas is 3%~15%; coke oven gas is 5%~36%; liquefied petroleum gas is 1.6%~11.1%. The larger the explosion limit range and the lower the explosion limit of the fuel gas, the greater the explosion risk.

In order to avoid safety hazards caused by fuel gas leakage into the furnace, the burner is equipped with corresponding automatic combustion procedures, flameout protection devices and other safety protection systems. Generally, oil and gas burners have a pre-purge time before combustion, that is, before the combustion arc is generated, the burner fan has a purge process in the furnace.

What is the process flow of Oil and gas dual fuel burner?

During this process, the combustible gas that may still remain in the furnace can be discharged outside the furnace, thereby avoiding the occurrence of deflagration. In addition, during the operation of the oil and gas burner, if the flame subsides but the fuel delivery continues, a large amount of combustibles (gas or oil and gas) will accumulate in the furnace, posing a risk. Therefore, oil and gas burners have a flame monitoring system to maintain the system when the flame is extinguished, that is, the operation of the burner is immediately stopped when the flame is cut off. These are the two most commonly used flame monitoring methods. The presence or absence of the flame can be confirmed by ionization or ultraviolet detection.