A detailed explanation of burner selection rules and air volume adjustment in rotary kiln

 News     |      2020-07-03 16:16

The burners of rotary kilns in medium-sized plants should adopt multi-channel burners with oil injection ignition device and a set of oil supply system for the burner ignition.The length and Angle of the burner should be adjustable and should be fixed with suspension or support.The burner of rotary kiln should be determined according to kiln type and coal quality.Multi - channel burner is one of the most advanced and widely used pulverized coal burner in rotary kiln.Its characteristic is: an air volume is small, can adjust the shape and length of flame, flexible for different ash content of coal quality, strong adaptability to different pulverized coal fineness, especially in the case of higher ash content, make it achieve complete combustion, thus not only better adapt to complex combustion condition, increase the combustion efficiency, and also has more obvious effect for reducing energy consumption.The proportion of primary air volume of multi-channel pulverized coal burner to theoretical air requirement should not be more than 15%.

The flame and air volume of material burners calcined in rotary kiln are very important to the production of equipment. It is not easy to control the air volume adjustment of the burner. Too large or too small will affect the calcination quality of rotary kiln.

 

Kiln head burner plays an important role in calcination of clinker in rotary kiln. Its performance and adjustment directly affect calcination in rotary kiln and the service life of lining.

 

Firstly, the opening degree of butterfly valve of external air, internal air and central air of the burner should be adjusted reasonably to improve the local coal concentration in the area before the ignition of pulverized coal, strengthen the internal and external backflow of high temperature gas in the burner, and strengthen the full mixing of primary air to achieve complete combustion.

 

But at the same time, we should pay attention to the fact that the internal wind should not be adjusted too much, otherwise the coal powder may be diluted before the fire, which is not conducive to the fire, or it may cause the high temperature flame, wash the kiln skin, and cause the kiln skin to fall off, which is not conducive to the protection of the firebrick.

 

For the adjustment of internal wind, the adjustment should not be too small, or the pulverized coal will not mix with the air soon after ignition, which will lead to the reduction of the reaction rate of pulverized coal and the timely oxidation of carbon monoxide into
carbon dioxide, resulting in the reduction atmosphere in the kiln.

 

In addition, the external wind is not easy to adjust too large, otherwise it will cause the burning zone flame to move back, part of the kiln end to form thick kiln skin, or appear the phenomenon of ring and egg laying near the transition zone.The external wind should not be too small, otherwise it will not produce a strong flame, not conducive to calcining good quality clinker.