Rotary kiln lime roasting process

Abstract

The invention discloses a rotary kiln lime roasting process comprising the following steps: (1), putting a raw material namely lime into a preheater for preheating at first, guiding the flue gas generated by pulverized coal combustion in a rotary kiln into the preheater to preheat the lime by using waste heat, and then discharging the lime, wherein the preheater is communicated with the kiln tail of the rotary kiln; and (2), roasting the preheated lime discharged from the preheater in the rotary kiln which is heated by burner nozzle pulverized coal injection, adding the roasted lime into a cooler from the kiln head to perform cooling, and finally discharging the cooled lime from the bottom of the cooler, wherein in the step (1), a pulverized coal spray gun is arranged at the lower part of the preheater to spray the pulverized coal accounting for 5-30% of the coal spraying quantity of the burner nozzle of the original rotary kiln into the preheater so as to improve the preheating temperature in the preheater, and the pulverized powder sprayed into the preheater is independently measured.

Description

technical field [0001] The invention relates to a limestone roasting process, in particular to a rotary kiln lime roasting process. Background technique [0002] Lime rotary kiln is an advanced kiln type for roasting lime, which has the advantages of high automation, large output, high product quality and less operation. At present, the main disadvantages of domestic lime rotary kilns are: the temperature field in the rotary kiln is uneven and easy to form rings, and the emission of NOx is relatively large. The ringing problem is common in the rotary kiln. Depending on the operation, limestone raw material, fuel, etc., the length of the ringing formation cycle and the severity of the ringing are different. The ring formation has a great impact on the normal production of the rotary kiln. When the ring formation is serious, the kiln must be stopped for treatment, which seriously affects the continuous production and production cost of the rotary kiln. The ring formation also...

AI Technical Summary

Problems solved by technology

At present, the main disadvantages of the domestic lime rotary kiln are: the temperature field in the rotary kiln is uneven and easy to form rings, and the NOx emission is large

The main reason for the formation of rings is that the amount of coal powder sprayed and the length of the burning flame are not well controlled, the burnout rate is low, and the temperature field in the kiln is uneven.