85 posts
Coating on Nose ring
Sir,
I am frequently now a days facing the problem of abnormal heavy coating formation (About 300-350 mm thickness ) only on the nose ring area ( 0-0 to 0.8 Mtr ) .This i feel is creating the problem of high free cao and operation disturbances. We have castable with 60 % silicon carbide applied in this region. In addtion to the thickness of coating its extending outside by about 300 to 400 mm outside resulting in clinker falling a bit farther away. Chemical composition and sulphur alkali contents are within the limit. Can somebody throw more information on this??
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537 posts
re Coating on Nose ring
Hello,
Coating formation in this area is normally the result of too much liquid being present in the clinker leaving the kiln. This is often caused by the burning zone temperature being too high, and/or a higher than normal liquid phase content. Also, your burner pipe tip may be too far back, which reduces the length of the primary cooling zone (under the burner) and allowing too much melt to exist at the nose ring.
A high dust load in the secondary airflow coming back from the cooler will make this problem worse. Also, kilns with nose-ring buildups often also have frequent problems with snowmen in the cooler... for the same reasons. Is this the case with your kiln?
The first thing I would do is to try to reduce the burning zone temperature. The next thing you could try is moving the burner further into the kiln, if that is possible.
As a very last resort, you could try to increase your Silica Ratio to lower the liquid phase content. The optimum is 24-26, however that will depend on your kiln configuration and raw material burnability.
Good luck!
Regards,
Ted.
20 posts
re Coating on Nose ring
Hello,
You need to optimize the cooler operation to avoid nose ring coating formation.
What type of cooler you have? Whether it is with fixed inlet?
How much cooler bed height you are maintaining?
Please give the detils for further study.
85 posts
re Coating on Nose ring
Thanks Mr Ted For the valuable information. The reason for keeping high kiln torque/B.zone temp is to avoid high free lime.We have hot raw meal SO3 of 1.0 to 1.5 %, R2 O of about 1.O % and CL2 % of 0.7-0.8%. Can you tell me why there is high free lime even though our clinker HM shows 2.12% SM 2.53% IM 1.45. Its to keep the free lime under control that we are going for high torque.As to Mr GSM our cooler 1st 7 grates are IKN Stationery grates and remaining are movable grates. We are keeping the cooler bed thickness of 500mm.Approximately.