3 posts
TimePosted 08/07/2010 09:46:20
ainkaya says

clinker emissivity factor


i have been searched clinker emissivity factors, but i havent found any information.

is there anyone that know any information about it ?




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138 posts
TimePosted 08/07/2010 10:14:25
lalbatros says

Re: clinker emissivity factor


I assume that you are asking about the emissivity factor to be used to calculate the irradiance of hot clinker.

I think you can safely assume that the clinker emissivity is close to 1 .
Anyway, the clinker surrounding, refractories and dusts (and combustion gas) have an overall emissivity that is also very close to one. In this case, an analysis of the complete kiln radiation leads to the conclusion that the emissivity of clinker don't play a significant role. Furthermore, the clinker bed is dusty and has an irregular shape, which should also push the effective emissivity close to 1.

The same question could be asked for the gas. As the gas in a clinker kiln contains a lot of CO2 and eventually also H2O, it also has a higher emissivity/absorbtivity, although it should be far from opaque for the "small" dimensions of a kiln. Nevertheless, if you take dusts into account, you will see that accounting for the gas CO2 composition is a useless refinement.

You will find all the necessary formulas and many data in the wonderful book by Boateng . The five papers by Locher are also interresting (see Mathematical models for the cement clinker burning process, ZKG, 2002).

Curious to know what you will be doing with that and if you will have fun with that topic.