re Re: Kiln Inlet Coating

Hello Ted,

Thanks for your suggestion. As you said, there is no significant increase in the Alkalis and Chloride in hot meal, only increase in SO# is observed.

Also, there is no extra input of sulfhur from raw meal. However, the CV of fired Coal (mixture of Coal and Pet Coke), has increased from 6600 to 7000, thus, the sulphur input from coal has increased. 

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re Kiln Inlet Coating

Dear Ted;

Although we are using the gas (with 0% H2S) as fuel and our kiln feed sulphur content is low 0.3% with (S/A) ratio between 0.7-0.8, we are facing problem of kiln inlet heavy coating and hot meal with 2 to 3 (S/A) Ratio which is very high.

You have mentioned in your answers that " Usually coatings or buildups in this area are due to an elevated sulphur cycle caused by either poor combustion in the main flame ..." .

My question is how does poor combustion elevate sulphur cycle in the system?

Best Regards

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re Kiln Inlet Coating

Hello Abdulla,

The volatility of sulphur in the kiln is highly dependent on the chemical composition of its compouds.

Sulphur as SO2 is 100% volatile, but if oxygen and alkalis (K2O or Na2O) are present in molar equivalence then alkali sulphates are produced which are much less volatile than SO2 or SO3. These alkali sulphates can then escape the kiln within the clinker.

For example, the reaction of SO2 with K2O is;

2 SO2 + 2 K2O + O2 ---> 2 K2SO4

From this you can see that even with low sulphur inputs and low SO3/Alk ratio, if there is not enough oxygen present the reaction will not proceed and sulphur will continuously recycle and form buildups/coatings in and around the kiln inlet.

To summarise;-  Poor combustion in the main burner will cause a lack of oxygen at the kiln inlet, preventing the conversion of sulphur to alkali sulphates which will result in an elevated sulphur cycle and subsequent buildups in the kiln inlet.

I hope this helps you.

Regards,

Ted.

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re Re: Kiln Inlet Coating

Dear sir,

         I want balance  Hot meal So3, Na2o, K2o and CL  with respect to clinker .with same amount to avoid kiln inlet coating formation in calcination zone , kiln riser duct ,  bottom cyclone cone and feed pipe.

   I get hot meal composition

              S03 - 2.5 - 3.0,  Na20  0.3 -0.5 K2o 1.5 -2.5  and Cl 0.5-1.8

              Clinker -  So3 ---  1.3 -1.6 ,(N20 +K20 )  0.8 and cl 0.0002,

      O 2 AT Kiln inlet riser duct  3.5% to 5.5.% for 95%pet coke &3.0 -5.0% AF,

    One problem also coming on high o2 level at kiln inlet higher Nox formation take place..

. How to control NOX formation with control hot meal  to avoid jamming and coating formation.

 GKS

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