System structures of thermal oil furnace burners

If a large amount of combustible gas accumulates in the thermal oil furnace burner (such as gas leakage or fuel oil evaporates into oil gas in the high-temperature furnace) and reaches the explosion limit, it will produce deflagration during combustion, which will pose a serious danger to the safe operation of the thermal oil furnace burner.

The 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, industrial burners are equipped with corresponding automatic combustion programs, flameout protection devices and other safety protection systems. Generally, the thermal oil furnace burner has a pre-purge time before combustion, that is, before the combustion arc is generated, the burner fan has a purge process in the furnace. During this process, the combustible gas that may still remain in the furnace can be discharged out of the furnace, thereby avoiding the occurrence of deflagration. In addition, during the operation of the thermal oil furnace burner, if the flame dies down but the fuel delivery continues, a large amount of combustibles (gas or oil) will accumulate in the furnace, posing a risk. Therefore, the thermal oil furnace burner has a flame monitoring system to maintain the system when the flame is turned off, that is, the operation of the burner is stopped immediately when the flame is turned off. These are the two most commonly used flame monitoring methods. The presence of the flame can be confirmed by ionization or ultraviolet detection.www.burners-china.com