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.

Our ESP on our long dry kiln (2520tpd) is out of order. A certain company has recommended instead of the ESP to install a water fogging system (droplet size = 10 micron) into the riser pipe of this kiln claiming that 80 per cent of dust passing with exit gases before the ID fan can be suppressed that way. Can you advise us on the merits and/or disadvantages of such a system?

I am afraid I cannot see many merits to this suggestion. It is common practice to condition (humidify and cool) the gases before entering the ESP by spraying droplets of water into the gas stream in a conditioning tower. This might indeed lead to 80 per cent of the dust load dropping out in the conditioning tower. However in your kiln, the suggestion is not to spray into a tower that will act as an expansion chamber but into the gas riser. You will also cool and contract the volume of the gases, which will have the effect of increasing the draft at the kiln inlet leading to the possibility of higher dust losses from the kiln. I could not advise such a modification and believe that a much more detailed examination of the problem is required.