232 posts
TimePosted 26/09/2010 05:41:45
xxxx says

Reduction in clinker production

My kiln is FLS SLC with uniflow burner.

after a 7 days stoppage of lining we are facing problem of continous CO formation at kiln PH (0.2 to 0.5%) with 5 % oxygen. We are not able to put more coal in kiln burner & there is  a reduction of production by 20-25 tph clinker.

Remaining papameters are same . Like burner pipe dimensions & primary air flow etc. Raw Mix is same  & Coal Mix is also same.

At kiln inlet I got 2% oxygen & 2 % CO.

why the coal is not getting burnet . Coal residue is also 5% on 90 mic. same as previous.

Is anything wrong with the burner pipe position.

In calciner firing we do not have any CO.



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57 posts
TimePosted 27/09/2010 15:45:00

Re: Reduction in clinker production

2% CO at kiln inlet should be unacceptable.

You should try increasing the draft to increase the oxygen at kiln inlet to see the effect on the CO.

My guess is that your kiln inlet probe is not perfect and gives you an O2 reading that is higher than reality. Your main burner flame is then starving for O2. This results in colder, longer flame with difficulty to maintain the burning zone. Adding more coal without increasing the draft would make matter only worse.

I f this does not work, than you have to check all parameteres of your burner, especially pressure and flows of air.

Best regards,



10 posts
TimePosted 01/10/2010 02:57:50
maddy says

Re: Reduction in clinker production

Dear Raj,

Which plant are u talking about.  Is it in India.  I am FLS Commissioning Engineer.  Please check the coal firing blowers (did u change anything on blowers).  What is the fine coal moisture (present and before shutdown).  Since it is SLC what is the percent of coal firing in calciner and kiln compare the situations. 

Do you have any coating at kiln inlet. Your saying everything is same.  Did u have any change in coal (pleae check the Sulphur  in coal content.)

Best Regards,



44 posts
TimePosted 10/10/2010 11:59:54
Davo says

Re: Reduction in clinker production

In the case you explained, the core of clinker must be brown.

Chek in your clinker FeO content (it must be high also, ap. 05-07%) Fe2O3-Fe3O4-FeO (reduction reaction).

look inside the kiln is in the kiln dusty condition or not?

Reducing condition take place because of lack of air or unnormal firing.

You have to work some hours with half produdtion rate of kiln and look what happens. If the CO cotent normal, slowly add the material.

Look in the location of the burner, and adjust it (lift up), if the burner is down and flame is direct on the material.

Chek if there is a coating in your kiln system, especially in the begining of the sintering zone, if yes you have to stop kiln and replace the coating, or advanced operators have to collapse the coating with burner combinations.

Do this combinations one after another, not all togetther. And I'm sure eveything will be OK.