I want to know about calculation methods of gas and material flow in preheater, pc, kiln, cooler. Further, can you advise why we are getting brown clinker problem in our 2000tpd off-line calciner kiln from which we are recently producing 2500tpd while having 90-91 LSF, 2.26 SM, 1.4 AM and kiln feed residue up to 22 per cent. How we can improve our clinker quality?

The calculation of gas and material flow in the preheater relies on the principles of stoichoimetry (to assess the combustion gas products from the fuel) and the conservation of mass. In principle what goes into the kiln must come out somewhere and will allow you to prepare a mass balance for the kiln. With regard to the brown clinker you are producing this is most probably caused by having reducing burning conditions in the burning zone of the kiln. This is very bad for clinker quality and fuel efficiency of the kiln. Almost certainly the problem is with the kiln burner and might be solved by adjustment. You must be sure that you maintain at least one per cent oxygen at the kiln inlet.

We need to know the distribution temperature on preheater kiln - in-line calciner - double string - four-stages cyclones cross bar cooler , kiln diameter 4.8 metre, kiln length 67 metre, kiln KHD design, and the collar from FLS, kiln feed 320 ton /h, dry kiln, by pass 20 per cent, preheater fan capacity 380,000 m³/ h. Also the type of bricks is Almag 85 per cent , perlix 80 per cent , kronex 85 per cent ...etc.

The shell temperature profile varies with the kiln process (precalciner, preheater, long dry, wet etc.), type of refractories installed (due to different conductivities), the residual thickness of the refractories (which reduces with wear during service), and the thickness of coating on the refractories (which changes dependent on process conditions). For an in-line calciner kiln I would expect shell temperatures of around 200 degrees C for the first 30 per cent of the kiln length where you will have the more insulating refractories installed. The girth gear will be in the region and the shell at this approximate temperature. I would then expect the shell temperature to rise to around 300 degrees C in the upper transition zone from 30 to 60 per cent of the kiln length. The refractories are likely to have little coating in this area. In the burning zone from 60 to 90 per cent of kiln length the shell temperature will be very variable due to coating formation. It could be as low as 150 degrees, but if the coating breaks away and the residual lining thickness is low then it could rise to over 400 degrees.