Working Principle and Adjusting Method of Gas Burner
Kiln burner kiln clinker calcination has a pivotal role in its performance is good or bad and adjust a direct impact on the calcined kiln and kiln lining service life. Reasonable adjustment of the outer air of the burner, the opening of the butterfly valve in the inner and center winds, the localized pulverized coal concentration in the region before the pulverized coal ignition, the internal, external and backflow of the burner high-temperature gas, and the complete mixing of the primary air, . But it must be noted that the wind can not be adjusted too much, otherwise it may lead to coal before the fire had been diluted, this hand is not conducive to fire, or may cause high-temperature flame, washed kiln skin, resulting in kiln skin off, is not conducive to the protection of refractory bricks . The wind can not be adjusted too small, or after the ignition of coal and air can not be quickly mixed, it will lead to lower rate of coal powder reaction, causing a lot of carbon monoxide can not be timely oxidation of carbon dioxide, resulting in reducing atmosphere kiln. In addition: the wind should not be adjusted too large, otherwise it will result in burning with a flame after the shift, kiln kiln end of the junction thick kiln skin or in the vicinity of the transition zone knot, egg phenomenon, the wind should not be too small, otherwise Can not produce a strong flame, is not conducive to calcining a good quality clinker. Therefore, according to the specific circumstances, select the appropriate operating parameters, according to the quality of coal quality, fineness, moisture, secondary air temperature, the kiln and St. Louis burnability is good or bad, by adjusting the best outside wind, The proportional relationship between the internal wind and the central wind, and the reasonable position of the burner near the kiln mouth, to determine the appropriate calcination system.
1. Gas Burner positioning
Many companies use the "light beam method" positioning, accurate control, but the operation is not convenient. The best use of the position scale in the kiln head section, the general control in the kiln section of the X-axis slightly right-side position or slightly less than the location of the fourth quadrant effect is better. In the case of special technology can do a little fine-tuning.
2. Effect of flame shape on calcination
The best flame shape of the burner design is the axial wind and swirling wind in the (0.0) position (at this time the maximum ventilation duct duct), when the flame shape intact and powerful. The shape of the flame is adjusted by adjusting the ventilation cross-sectional area of each duct. At the (0.0) position, the cross-sectional area of the axial and swirling winds is maximized.
The flame shape is obtained by mutual influence of cyclone and axial wind, and the stability of flame shape is realized by central wind. The wind quantity of center wind can not be too big nor too small. General central air pressure should be controlled between 6-8KPa ideal, swirling wind in the 24-26KPa, axial flow in the 23-25KPa, the ventilation cross-sectional area of not less than 90% of the cases, the parameters of the Adjustment. To obtain the flame shape change requires a stable primary air outlet pressure to maintain, by stabilizing the pressure on the burner to change the ventilation cross-sectional area of each branch to achieve the purpose of changing the shape of the flame. The specific flame shape changes.
When adjusting the flame shape, to put an end to the phenomenon of extreme, when the flame is too thick, this time will be very long, very soft. When the flame is too small, the flame will be too short, firing with the requirements of the shape of the flame is complete, lively, powerful, which requires our long-term observation and lessons learned.
The influence of coal quality on flame shape
(1) When coal ash content becomes high, the combustion speed of pulverized coal slows down, the flame grows longer and the flame burning belt becomes longer, it is necessary to increase the secondary air temperature or use more secondary air, strengthen primary air and secondary The wind and the degree of mixing of coal powder; ② reduce the fineness and water content of coal; ③ change the axial flow and swirl wind with the wind ratio; ④ increase the amount of wind, reduce the concentration of coal in the primary and secondary air .
(2) When the coal volatile high, the coal fire fast, coke particles around the oxygen concentration decreased, easy to form from the kiln near, stable low, high temperature part of the longer flame, this time should increase the flame around Of the oxygen concentration; ② increase the axial flow of wind and wind speed (in the original state of the flame); ③ increase the amount of wind and air.
(3) When the coal moisture increases, the external moisture can be increased by raising the grinding gas temperature to reduce the internal water needs to be about 110 ℃ to evaporate, coal mill to reduce the intrinsic moisture content is very difficult. Into the high water into the kiln, the flame will become longer after the flame, burning speed slows down, the flame temperature is low, the black flame head longer, then the secondary air should be appropriate to increase the role of combustion flame, the secondary air and a Wind the amount of wind mixed to improve the secondary air temperature, appropriate to exit some of the burner, the use of secondary air to improve the flame burning speed, to improve the flame temperature purposes.