Good mornig everyone,
Why the thermal load is very important in kiln operation? what is the maximum thermal load? and how can we measure it?
saprina
Michael Clark
Hi Saprina,
Thermal load is important because the refractory lining in the cement kiln can only withstand a certain thermal load and give extended service. If the thermal load is too high then refractory wear will be high and frequent refractory lining failures will occur. The critical point is the burning zone of the kiln where the temperatures and thermal load are highest. In long wet or high capacity preheater kilns this can exceed 25 GJ per hour per metre squared (GJ/hm2). To measure thermal load you must calculate the thermal input to the kiln through the main burner in GJ per hour. Then calculate the cross-sectional area of the kiln inside the refractory lining. Divide one by the other and you have the thermal load.
Thanks
Dr Michael Clark
Thermal load is important because the refractory lining in the cement kiln can only withstand a certain thermal load and give extended service. If the thermal load is too high then refractory wear will be high and frequent refractory lining failures will occur. The critical point is the burning zone of the kiln where the temperatures and thermal load are highest. In long wet or high capacity preheater kilns this can exceed 25 GJ per hour per metre squared (GJ/hm2). To measure thermal load you must calculate the thermal input to the kiln through the main burner in GJ per hour. Then calculate the cross-sectional area of the kiln inside the refractory lining. Divide one by the other and you have the thermal load.
Thanks
Dr Michael Clark
Saprina
Hey;
Thanks alot Dr. Clark for your answer but i don't know how to calculate the thermal input to the kiln through the main burner in GJ per hour!!!
Saprina
vinayak
Hi
You may multiply the fuel feed by CV For ex
Kiln fuel feed rate = 6000 kgs/hr
C.V = 6500 Kcals*4.184 = 27196 Kj/Kg of coal
Thermal Input = 6000 X 27196 KJs/Hr
= 163.176 GJs/Hr
Kiln dia (inside Lining) = 3.6 m
C.S Area = (3.14/4)*3.6*3.6
=10.17 m2
Thermal load on kiln = 163.176/10.18
=16.04 Gj/hr.m2
Regards
Vinayak