Low nitrogen combustion technology for cement plantsDate: 2019-06-25 Views:
1. Introduction to the whole process low nitrogen combustion technology
In the operation process of fractional combustion technology and recombustion denitrification technology, in addition to the hardware facilities of air and coal separation, the whole-system fine operation centering on the main line of combustion is also required. The extensive operation mode cannot effectively reduce the nox emission.The whole process of low nitrogen combustion technology is the grading combustion technology on the basis of the further development of technology, to reduce the system NOx emission will kiln preheater and calciner of full system, rotary kiln, pulverized coal burner, three times in the duct and pulverized coal and raw meal feeding as a organic whole system control, from the inhibition of the formation of NOx and NOx reduction has generated two aspects of preparation of fuel quality, quality, and reasonable distribution of fuel and combustion air burner influence factors such as the rotation of the momentum and axial momentum to carry on the scientific and reasonable regulation, implementation of furnace temperature and atmosphere in the field of systems and control,NOx formation control and reduction decomposition are realized in the whole process of kiln.This plays an important role in the process of cement production line.
2. technical transformation
The transformation mainly includes the following parts:
2.1 kiln tail pulverized coal conveying pipeline and decomposition furnace burner
In the former cement production plant,To redesign and decomposition furnace coal feeding point arrangement, the two original decomposition furnace burner position unchanged, increase 2 burner in the cones of decomposing furnace, after transforming the cones 2 amount of feed coal burner is 30% of the preheater feed coal, excess air and pulverized coal excessive use stove CO formed by incomplete combustion and CxHy reduction material, achieve the reduction of decomposing furnace area downstream extension upwards, enlarged the reduction region, reduction of the formation of NOx in the rotary kiln, the formation of NOx and curb fuel type.
2.2 transformation of air duct for three times
Increased three times the wind in the upper branch connection to decomposition furnace, drew 15% ~ 20% of three times the wind to break down the upper furnace, dissolve excess air coefficient in the furnace part around 0.85 become lean oxygen reduction zone, reduction in rotary kiln clinker calcining type thermal NOx of NOx and fuel type, and inhibition of bituminous coal combustion in new generation of fuel type of NOx.
2.3 raw material cutting transformation
The blanking of C4 preheater is divided into three blanking ports, which are arranged in the middle and cone of the decomposition furnace respectively.Adjust the proportion of raw material from C4 feeding valve to the bottom of decomposition furnace in operation at the same time, to prevent the local temperature from being too high and resulting in crust.