Working principle of boiler burner

The swirl burner consists of a circular nozzle, and various types of swirl generators (cyclones for short) are installed in the burner. When the pulverized coal airflow or hot air passes through the cyclone separator, it rotates and is ejected from the nozzle to form a rotating jet. By using the rotating jet, a high-temperature flue gas recirculation zone which is beneficial to ignition can be formed, so that the airflow can be strongly mixed.

After leaving the nozzle, a backflow zone is formed in the center of the airflow, which is called an internal backflow zone. The high temperature flue gas in the furnace is sucked into the internal reflux area to heat the pulverized coal airflow. When the pulverized coal airflow has a certain amount of heat and reaches the ignition temperature, it will start to catch fire, and the flame will spread outward from the inner edge of the internal reflux zone. At the same time, a recirculation zone, called outer recirculation zone, is also formed on the periphery of the rotating airflow. The external reflux zone also sucks high-temperature flue gas to heat air and pulverized coal airflow. Because the secondary air also forms a rotating airflow, the mixing of secondary air and primary air is relatively strong, which makes the combustion process continue to develop until it is burned out.