How much do you know about the common failure of cement rotary kiln?Date: 2019-07-22 Views:
Rotary kiln is the heart of cement factory, its main characteristics are large weight, high working temperature, cylinder steel plate thin, easy to deformation, with a series of meters, the requirements of a higher level of operation.Therefore, often due to equipment failure or operational errors, and cause various accidents.Generally speaking, the economic loss of rotary kiln is large when the kiln is stopped due to accident, so it is necessary to avoid all kinds of accidents or faults to reduce the frequency and time of stopping kiln, which is of great significance to stabilize the thermal system of kiln, improve the output and quality of clinker, reduce the labor intensity of maintenance and increase the economic benefit.
1. "red kiln" of rotary kiln
Burn mature in raw materials, in the process air temperature reaches 1600 ℃ above, sometimes as high as 1800 ℃, the material temperature of 1450 ℃, the barrel of the firing surface temperature of 200 ℃ to 300 ℃, innovation kiln of masonry of refractory brick and stick to hang in the skin have played an important role in protection of cylinder, the cylinder is not being burned by high temperature and prevent or reduce the temperature of the furnace heat spread outward from a cylinder body.
But when kiln and brick due to erosion wear time is long, or due to cylinder crushed when the deformation of the shell plate will be directly affected by high temperature and direct calcine by flame, plate burning red or dark red, this kind of phenomenon is "red kiln", serious when steel happens to soften, cause a convex concave deformation of the cylinder local position, even cylinder do burn, a serious accident "red kiln".
"Red kiln" has the following reasons:
1) selection and quality of refractory brick;2) quality of firebrick masonry;3) raw ingredients formula;4) forging and firing operation level;5) kiln body itself, such as the cylinder is not circle, the center line is not straight, not enough stiffness, radial deformation is large, cylinder, cylinder radial deformation due to insufficient rigidity, for a point on the cylinder, cylinder rotary week, its outer convex concave radial deformation to undergo six times in variations, this clearly is the main cause of the kiln lining is loose and fall off.In the actual production, in order to know the heating and temperature of the kiln barrel (mainly the firing belt) at any time, the workers should regularly touch the barrel surface of the firing belt (there is a water spraying device in this section), and judge whether the temperature is normal by feeling and experience.
2. Burn the chain in the kiln tail tube
The biggest disadvantage of the wet rotary kiln is the low heat utilization rate, the general waste gas with 20-30% of the heat, so in the end of the kiln equipped with a chain, slurry moisture is initially evaporated, so that the waste gas to reduce the heat to 10-6%.However, in the process of production, due to improper operation and other reasons, there will be a major accident of firing and melting chain or sintering.Such accidents usually occur in the forging and firing stage after stopping the kiln for maintenance.Therefore, the operators should strengthen the kiln head fire operation, strictly follow the operation rules, after stop the material must ensure that there is enough water to add the kiln tail.
3. Kiln cylinder crack
Cylinder is the main body of the kiln, it is made of different thickness of steel plate rolled into sections and welded, the general design service life is about 30 years, but due to manufacturing, installation and use of improper, as well as incorrect maintenance methods and other reasons, cylinder steel plate often early appeared cracks, or even cracking caused accidents.
Crack treatment method: after the cylinder body appears crack, because of the reasons of preparation work, accessories supply and other aspects, generally can not immediately replace the crack cylinder body, often take "riveting reinforcement" or "welding repair" temporary measures.In the process of welding and repairing, we have worked out practical technological requirements, such as preheating temperature and method, groove method, groove type, electrode brand, welding method and speed, etc., and the effect is better after welding.
According to the above analysis, it can be seen that the common faults and accidents of rotary kiln equipment are various, and the causes are not only the same.As long as we strengthen the daily maintenance and operation, and with the help of some advanced instruments and other modern testing means, we can easily manage, use and maintain our large kiln, so that the rotary kiln maintains normal operation.