1156 posts
Burning Question 41
Our preheater surging regularly. This is happening on a irregular basis. We suspect it is coming from cyclone No 2. We have investigated and have taken several actions. Unfortunately, we were unable to resolve it. Actions taken were as follows:
1. Damper adjustment
2. Check feeding system
3. Effects from other cyclones
4. Preheater riser duct buildup
5. Splash plate adjustment/buildup
We also include some technical data as an attachment.
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1156 posts
Re: Burning
Please ask the laboratory to check the LOI in C1A, C1B and C2 again. The reported LOI in C2 is higher than in the C1 cyclones. This is difficult to explain unless you have some water injection into C2 cyclone or other special process feature. In order to calculate the cyclone efficiencies the LOI should reduce in each successive cyclone down the preheater.I also suggest that the LOI at 600 degrees C be measured in addition to the LOI at 1000 degrees C. This will tell us whether there is any hydrate or organic carbon present in the kiln feed. Finally we must have the dust LOI to calculate the efficiency of the C1 cyclones.
1156 posts
Burning Question 42
I witnessed a phenomenon at a plant here in Europe, which could not be explained by anybody there. At one plant I found ring formation at the upper transition zone in a rotary kiln at three different areas. The plant is burning alternative fuels like house trash, plastics and bone meal. I was told, that all actions taken with regards to the process, have not been successful. My questions are:
1. Is there anything you could recommend apart of the standard procedures to avoid coating formation?
2. Do you know, if there is any refractory manufacturer who does supply are fractory solution for this matter and what should be the technical data for such a refractory?
1156 posts
Re: Burning
The rings you describe must be ash rings formed where the ash from the different alternative fuels combine with the charge in the kiln. It is not uncommon for coating and rings to form at that point in the kiln. As there are three distinct rings I suppose than the different alternative fuels have different aerodynamic properties in the kiln, or different delivery systems injecting them into the kiln and this is causes the ash to combine at different positions. If that is the case I would adjust the different fuel injection velocities to try to even out the coating. I am not aware of are fractory solution to this type of problem in the lower transition zone. I suggest you contact David Shepherd of Ceram Research who will know if such a solution exists, david.shepherd@ceram.co.uk.