23 posts
TimePosted 04/01/2012 09:44:24
emadissa says

Questions on burning stability & BZ ring formation


We are having 

  1. High flame impulsion (10.5 N.h/Gcal) for 100% coal
  2. Fluctuation on pre-calciner (RSP) outlet temperature (850 - 880 oC), caused by unstable coal feeding, leading to variable calcination degree (92 - 95%).
  3. Fluctuation on kiln feed LSF (97 - 120)
  4. AR = 1.45, SR = 2.75


  1. we are facing the problem of burning zone ring formation (at meter number 50); which one of the above may be the main reason of this problem?
  2. how can I determine burning zone length?

N.B. short dry kiln, 78 m useful length & 5.2 m useful diameter.


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STEAG Powitec - Albrecht Keiser
18 posts
TimePosted 20/02/2012 09:30:05

re Questions on burning stability & BZ ring formation

Dear Sir,

Burning Zone Length (BZL) depends mainly on the following variable factors (beside the static factors):

A) Burner type and burner settings (position, airs, swirl etc.)

B) Fuel properties (mixture, size, calorific value etc.)

C) Heat absorption rate from clinker (depends mainly on temperature clinker from pre-heting and mass flow clinker)

Please have a look at attached slide showing the influencing facts on flame form and thus BZL in a graph. All factors can be influenced but without additional analysis/measurement nobody really knows about the factual outcome for the BZL. This is why experts recommend using an additional instrument: The PiT Indicator Side View. This then enables you to analyse and measure the flame and the temperatures in the BZ. The gained data can then be correlated with process quality values like FCaO, Alites, Blites, C3S etc. which allows for optimising the BZL accordingly.

More information on http://www.powitec.de/English/Cem_PiT_IndicatorSideView.html or send me a mail: a.hanf@powitec.de

Best regards