Hello,

I have 2 questions on cement rotary kiln shell heat loss:

1. I have seen literatures claiming that kiln shell heatloss can be reduced massively by adding a stainless steel or aluminium jacket (Engin&Ari, 2004, Energy Conversion and Management, 46 (4), 2005, 551-562). Has anyone seen this done in commercial scale? Will the reduced heatloss results in very high shell temperature?

2. I believe the best solution to reduce kiln shell heatloss is still on refractories, but how far can it go? i.e., what is the lowest shell temperature one can get in a cement dry rotary kiln? Can it go down to <200oC?

Thnx

Hi

1. Yes, the heat loss can be reduced, but the impact on the refractory lining must be considered. This relies on the external air cooling of the shell. A temperature gradient is established in the refractory lining which limits penetration of the lining by the fluxes in the kiln. Use of a jacket has not been done on a commercial scale due to the likely failure of the refractory lining of the kiln.
2. Certainly refractory lining is the best means to reduce heat loss from the shell of a cement kiln. The limits depend on the the thickness of the lining, the lining material conductivity, its refractoriness, etc. You could achive <200 degrees C throughout the length of the rotary section of the kiln, but the lining thickness required would significantly reduce the internal volume of the kiiln and therefore the clinker production rate.

Regards

Michael Clark.
 

Agree with previous post. We achieved kiln shell temperatures at the level 210-270 oC on the magnesia bricks section. Without change of its height. But it was a job of 3 years long trials...