Untitled
Well, after getting a very rough measurement from the old lifters we replaced the main row for new ones. Unfortunately it has made the flow of material terrible. After quite a bit of research I have come to the conclusion that in order for there to be good drying of the material the lifters should be as follows:
The 1st row from the feed end should be the simple swirl type feeding the material from the feed chute to the centre of the dryer.
2nd row should be half height lifters with 90deg kicker. With half the height the material will tend to run over the lifters straight away so the drying process begins at the earliest point.
3rd row should be staggered against the 2nd and be full height with first kicker angle being 125 deg and 90deg at the very tip. This will lift the material to near centre and drop the dust parts in the core of the heat area.
4th row will be finger type full height with no kicker plate. This then alows the material to flow through the lifter from 4 0'clock through to 9 o'clock (when dryer rotates anticlockwise).
The final two rows will be the normal combustion type but with small kicker plates welded the whole length to disperse the larger element and concentrate the dust to the centre of the flame.
I'm not sure if any of this makes sense to anyone apart from myself, needless to say we wont know if it works until we try it 
If anyone can spot a potential major problem then please reply.
At the moment the baghouse temperature is knocking the plant out due to overheating, I'm putting this down to the fact that the lifters just aren't working correctly and that the curtain of material isn't falling in the actual heat as a whole.
Anyway, many thanks for any help given. ■
Aggregate Dryer
Hi there this is my first post so please be gentle....
I am newly appointed foreman at a large quarrying unit and am in charge of maintenance for the Asphalt processing plant.
The lifters in the dryer are very worn and we are struggling to achieve temperature. Is there a general lifter layout we should be following for the new lifters? There are no drawings of the original lifters and the ones in the dryer are so worn it would be very hard to get a good measurement for their replacement.
The dryer measures 9' internal dia and 33' in length. There are 1 row of swirl type lifters at the feed end followed by three rows of finger type lifters and two rows of plain combustion lifters. The material being dried is 40mm down to dust ranging from limestone to high PSV type aggregates.
I hope my first post will make sense to someone and that there is a light at the end of the tunnel. This will be my first major maintenance job in my new position and need all the help I can get... ■