We have ESP at the kiln system. It is also used for raw mill system. System is sent ESP's feedback to kiln feeding silo. There are two homogeneous silos and two stockage silos. Material is sent from ESP to homogeneous silos. So, my question is that, I am thinking to feed the ESP's feedback directly to preheater system but this line will be entered to system after weighfeeder. We have got line to feed this material before weighfeeder but it causes to reduce of fresh feeding. In this way I want to increase clinker production with same feeding amount. What do you think?

Your idea is a very good one. There are plants that do exactly what you propose. This has the advantage that the chemistry of the kiln feed is more stable because it is not destabilised by slugs of ESP dust being added to the homegenisation silo when the raw mill is not running. I am not sure that you will get more output but the kiln operation and clinker quality should be more stable.

What is function of preheater immersion pipe? What is the behavior of material inside cyclone if immersion pipe is missing ? If we have any immersion pipe missing it will effect on decarbonation degree or not ?

The function of the vortex finder is the improve the material separation efficiency in the preheater cyclones. If the vortex finder is not there then separation efficiency and preheater performance will decline. Yes, it will affect the decarbonation degree … some decarbonated material will pass back up the preheater and recarbonate. The biggest effects will be on fuel consumption and kiln output.