In the last issue, we introduced the influence of kiln work on the physical properties of refractory bricks. In this issue, we continue to introduce the influence of combustion and fuel nozzles on refractory bricks during kiln work.
2.The influence of combustion and fuel nozzles on refractory bricks
When coal is used as fuel, the volatile content and ash content of coal play a decisive role, directly affecting the shape of the flame. The pulverized coal with higher volatile content and lower ash content can shorten the black fire head and form a low temperature long flame calcination. It is generally beneficial to protect the kiln lining. But when volatile content is too high and the fire is too fast. The temperature of the clinker out of the kiln is as high as 260℃, and the secondary air temperature exceeds 900℃. It is easy to burn the nozzle, causing it to deform or break, creating a turbulent flame shape that may damage the kiln lining before it was replaced. If the volatile content of coal is too low (less than 0%) and the ash content is too high (more than 28%), the incomplete combustion of a large amount of pulverized coal will settle and burn in the material and release a lot of heat, which will damage the kiln skin.
Usually, fuel nozzle structure is not paid enough attention in production. The shape and outlet size of the nozzle mainly affect the mixing degree and ejection speed of the pulverized coal with the primary air. Sometimes in order to enhance the mixing of air and coal, wind fins are installed in the nozzle. But caution the excessive rotation range of the swirling wind to scratch the kiln skin.
Next issue we will continue to introduce how to protect refractory fire brick during kiln work.
