Please tell me, round nozzle burner coking problem
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The boiler is severely coked. When the inspection door is opened, it is found that irregular and intermittent small carbon fires are attacking the water wall, repeating the cycle, slowly forming a large area of coking. Please ask an expert to analyze the cause (four-corner tangential DC burner, primary wind speed 25M/S, round nozzle). It should not be pulverized coal segregation. Let me explain again: The tangent circle diameter is 350, and the installation angle of each primary air nozzle is not ideal according to the wire drawing measurement.
Is it a matter of separation of light and dark? The dense phase is on the fire side and the light phase is on the side away from the fire.
The main way to prevent coking of the round nozzle burner is to adjust the primary air pressure according to the level of volatile content of your coal! For coal with high volatile content, higher primary air pressure is needed to make the ignition point of the coal farther from the nozzle. ； The opposite for low volatile content!
The designed coal type is lignite, and Shenhua (coal blending #2) is currently being burned. We have considered the issue of wind speed and reduced the wind speed to 20~23m/s. The circular nozzle is an annular peripheral wind outside the primary wind, and the wind speed is 30~40m/s, so it is believed that coal powder generally does not segregate. I can't understand where and what the wall-painting thing comes from.
Increase the primary wind speed, reduce the fineness of pulverized coal, and redo the dynamic field of the cold circular cutting. It is possible that the circular cutting will be deviated.
The tangent circle has been proven to be deviated, and the existing conditions do not allow for correction. (Increase the primary wind speed and reduce the fineness of the pulverized coal.) According to on-site observations, the fire distance is too long. Why reduce the fineness of the pulverized coal?
Coarse coal particles require a long time to burn out, and often form a reducing atmosphere near the wall, which lowers the ash melting point, so it is easy to cause slagging in the burner area.
Well, I understand it is to increase the fineness of coal powder, but the explanation is different.