The role of pulverized coal burner
Date：2019-07-24 14:32 Source：未知Views:
Burner is the main component of pulverized coal furnace combustion equipment, its role is to put pulverized coal and combustion air into the furnace, reasonable organization of pulverized coal airflow, and good mix, promote the rapid and stable ignition and combustion of fuel.
The swirl burner consists of a circular nozzle, and various types of swirl generators are installed in the burner (cyclone for short).When pulverized coal airflow or hot air passes through the cyclone, it rotates and forms a rotary jet after it shoots out from the nozzle.By means of rotary jet, the backflow area of high-temperature flue gas which is favorable to ignition can be formed, and the airflow can be strongly mixed.
After ejecting the nozzle in the air flow center to form the reflux area, this reflux area is called the inner reflux area.The high temperature flue gas in the inner reflux area is used to heat the pulverized coal airflow. When the pulverized coal airflow has a certain amount of heat and reaches the ignition temperature, it starts to catch fire, and the flame spreads outward from the inner edge of the inner reflux area.At the same time, the periphery of the rotating airflow also forms the backflow area, which is called the outer backflow area.The outer backflow area also draws in high-temperature smoke to heat air and pulverized coal airflow.Since the secondary wind also forms a rotating airflow, the mixing of the secondary wind and the primary wind is relatively strong, which makes the combustion process continue and develop continuously until the combustion is exhausted.
A good burner should have the basic conditions of dacron:
(1) the primary and secondary wind outlet section shall ensure an appropriate ratio of wind speed;
(2) the outlet flow has enough disturbance to make the flow mix well;
(3) the diffusion Angle of pulverized coal airflow can be arbitrarily adjusted within a certain range to meet the needs of coal variety;
(4) the distribution of pulverized coal along the exit section should be uniform;
(5) the structure should be simple, compact, ventilation resistance should be small.