M.Azhar:

after adding the coal absorption factor what would be the final formula 

For a kiln system where all dust streams are returned directly to the kiln, the final formula would be;-

(1 - A/100) / (1 - R/100)

Where;-

A = coal ash absorbed into clinker (expressed as a percentage)

and

R = raw meal LOI (expressed as a percentage)

A is calculated by;-

A = (Tonnes coal fired * % ash of coal fired) / (tonnes of clinker produced)

(NOTE: 'coal fired' above means raw coal expressed on an air-dried basis. This is because fine coal from the the coal mill usually has 4-5% of raw meal dust contamination from the hot gases ex the preheater top cyclones. Alternatively, if the percentage of dust contamination can be accurately determined, this value can be used to correct the fine coal tonnes fired and calculate the dust-free % ash.)

Regards,

Ted.

Dear Sirs

Kindly , What about bypass ??? Is this the losses in the intervention material, especially if we know that there are a large proportion of this material was subjected to the process calcining. My question is whether this intervention the losses in the process of calculating the conversion coefficient of materials into clinker (Raw meal /clinker factor ??

Regards

ILA

ILA:

What about bypass ??? Is this the losses in the intervention material, especially if we know that there are a large proportion of this material was subjected to the process calcining. My question is whether this intervention the losses in the process of calculating the conversion coefficient of materials into clinker (Raw meal /clinker factor ??

Obviously in the case of a kiln bypass, where part of the kiln feed is being removed from the system and does not make up part of the clinker, this material would have to be allowed for in calculating the 'raw meal to clinker ratio'.

Because this bypass dust is essentially 'loss free', the mass of bypass dust removed needs to be subtracted directly from the calculated clinker tonnes. eg.

In a kiln which is being fed with raw meal at 350t/h and has a 'raw meal to clinker ratio' of 1.55 (calculated without respect to bypass), the actual amount of clinker produced with say 10t/h bypass dust removal will be;-

(350 / 1.55) - 10 = 215.8t

Therefore the 'raw meal to clinker factor' ,allowing for removal of this bypass dust, will be;-

(350 / 215.8) = 1.62

Best regards,

Ted.

In some kilns the return dust from BF and Gas cooling section directly mixes with the kiln feed ,In that case how to find out the ratio of conversion.

can it be done by the mass balance theory?