1156 posts
Kiln bypass Question 5
We would like to have your opinion and advice on following matters: our unit is a FLS design latest unit with downdraft calciner with 100 per cent petcoke. We have SO3 and chloride problem in our process, can you advise?
Secondly: how can we improve the clinker size as we are getting over-size clinker. For your reference we have included some sample data which we have collected from different places which may give you an idea about the material and our problems (data sheets as attachments).
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1156 posts
Re: Kiln bypass
There are a number of concerns regarding the data you have provided: (i)The K2O and Cl in the fifth cyclone material are too high. I would expect you to suffer blockage problems with this level of KCl in the hot meal. The only way to solve this will be via installation of a bypass. (ii) The SO3 content is high at the kiln inlet probably originating from the petcoke. I would expect some problems of ring formation in the kiln inlet and spillage of feed through the kiln inlet seals. (iii) The burning zone material is high in KCl and K2SO4. I am surprised by the amount of KCl present at these temperatures in the process. You need to tell me the Cl in the clinker for me to assess the ability of the kiln to pass Cl out in the clinker. With these levels of K2SO4 you must ensure the main burner is never operating in a reducing environment. It is clear you face very unusual conditions. I believe you need to develop a computer model of the volatile cycles in the kiln and use this model to test scenarios with a bypass to break the internal and external cycles in the kiln.
1156 posts
1156 posts
Re: Kiln bypass
There is a lot of data published on alkali bypasses in cement kilns. A good source of information is "Technological problems in pyroprocessing cement clinker: cause and solution", by S Sprung of the Research Institute of the German cement industry, and published by Beton-Verlag. The way to determine the percentage of bypass is to construct a computer model of the particular kiln process and use this model to evaluate scenarios with different percentages of bypass.