Advanced combustion technology for low grade and course alternative fuels: Sebastian Frie, ThyssenKrupp Industrial Solutions AG (Germany)
Filmed at Cemtech MEA 2015, 8-11 February, Grand Hyatt Dubai, UAE
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And it's my pleasure to show you today this technology and principle, and to give you also an insight into the first operational results of our first installation in Germany, which are quite promising. What is the Step Combustor about? It's some kind of green technology, so the idea is to make it possible to burn alternative fuels, that means wastes or bio-masses.
I think one of the major problems of our time is to get rid of those, especially of those municipal waste and you might know that it's quite a big effort in order to turn those wastes into some kind of fuels that can be burnt inside cement kilns. So, normally you have only a calciner loop of a combustion of fuel and towards entering zone burner, and into those cases it's necessary to treat the waste in a very deep way, so that the fuel is fly-able inside this calciner loop. So as a consequence normally you can only accept two dimensional particles,
that means foils or something like this. With a particle size around about 80/100 mm of which, so this is a necessary effort to produce such kind of fluid, which is fly-able and now with all our system which is some kind of great incinerator that is also used in incineration plants. You can now accept, they are very lumpy and cost alternative fuels which are non-fly-able, that means you can place the fuels on the grate of our combustor, and now you can accept very coarse particles that are 3 dimensional and have particle sizes of up to 300 mm.
The system itself is quite simple, it's just some kind of pipe, some kind of Calciner extension and you can see here an example of how it is adopted or re-co-fitted also to existing pre-calciners, here's an example of our design. So you have a combustor and the combustor is just placed at the bottom of Calciner loop directly over the Cane In-nets hosing.
Then you have a tertiary air connection which is going to the system, and you extract a meal from the second lower most cyclone and bring it to the units for the temperature control. So, basically it's a quite easy and it's possible to bring this system to any kind of pre-calciners. Let's go a little bit more into detail, here we have a site view of a system and you can see now here we have the grates, and as you can see the grates is formed in steps, that's the reason why we call it step combustor, and this grate has area which is suitable to burn the fuels for around about 15-20 minutes.
So, if you compare that to normal 3-5 seconds, you might have standard pre-calciner loop. You have particle retention time which is round about 300 times higher compared to the standard technology, and this of course has the big advantage that you really can burn almost everything inside here. Ignition is done with help of tertiary air, so you get the air from the clinker cooler, and the air is hot enough in order to make the ignition of fuels possible, that means, you do not need any kind of burner, or other equipment so that you'd just let the air flow above the grate which makes the ignition and also delivers of course the oxygen which is necessary for the combustion.
And you can see we have here a splash box at the tertiary air duct, so you just bring near to the air duct in order to get a good distribution of the meal and this meal starts before calcination reaction inside the unit and therefore we have temperature control or cooling effect of the meal here. The waste is brought to the system of a