How to Maintain Cement Rotary Kiln? Pay Attention to These Four Aspects!

时间:2020-12-29 作者 :adminhk

The operation of rotary kiln is characterized by heavy load, high temperature and continuous operation. Therefore, due to the rotary kiln has a certain slope and a long span between the front and the rear, the self weight, the long-term wear of transmission parts, the large temperature difference of the cylinder, the settlement of the gear foundation, and the improper use of the hydraulic block wheel, the large radial swing of the kiln cylinder may occur in the long-term process, resulting in serious material leakage at the kiln tail; the uncontrolled upward and downward movement of the kiln cylinder will affect the supporting wheels and wheels The results show that the service life of the refractory brick is shortened due to the frequent breakage and falling off of the lining brick of the rotary kiln.

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The reasons of kiln shell cracking are analyzed from three aspects

1. The cylinder is corroded. The existence of harmful gases such as R2O and Cl, especially P and s, will produce hot and cold brittleness and hot corrosion. In the area where harmful components are enriched, the cylinder is easy to produce corrosion pits, the thickness loss of the cylinder is more, the strength of the cylinder decreases, and the cylinder cracks under the action of bending moment for a long time.

2. The cylinder is deformed. The shell deformation occurs in the whole kiln body, and the ovality deformation is the most serious at the wheel belt, especially at the second gear wheel belt, where the temperature of the shell is high. If the gap between the wheel belt and the base plate of the shell is too large, the ovality of the shell will become larger, resulting in the increase of the compressive stress of the refractory brick, resulting in the fragmentation and falling off of the lining brick.

3. The straightness deviation of the cylinder is large and the stress is concentrated. When the kiln is shut down and turned over, the tension between the tyre and the supporting wheel set cylinder is too large.

So how to maintain the cement rotary kiln? Li Haitao made four suggestions

1. Rotary kiln shut down

(1) After the rotary kiln is shut down, the hydraulic station of the block wheel stops running. The electromagnetic directional valve of the circuit can not be powered at this time and keeps locked. The hydraulic system itself is set to meet the automatic pressure locking state, but the parameters such as the pressure gauge need to be checked regularly to ensure that there is no abnormal pressure relief;

(2) After the kiln is shut down in winter and before the kiln is planned to be rotated, the inside of each supporting roller Bush should be checked in advance, including lubricating oil, oil groove, oil spoon, etc. to ensure that there is no abnormality inside and the supporting roller Bush meets the lubrication conditions before the kiln can be rotated;

(3) Interval time of rotary kiln after shutdown. When the rotary kiln is in hot state: in the first hour of shutdown, 1 / 4 of the kiln will be rotated every 5-10 minutes; in the second hour, 1 / 4 of the kiln will be rotated every 15-20 minutes; in the third hour, 1 / 4 of the kiln will be rotated every 30 minutes; in four hours and above, 1 / 4 of the kiln will be rotated every hour until the kiln shell is cooled to normal temperature. After the rotary kiln cylinder is cooled to normal temperature, the kiln is rotated for 1 / 4 circle every 24 hours; when the kiln is stopped for a long time (the cylinder is at normal temperature), according to the maintenance situation, in order to prevent the kiln from bending and deformation, the kiln is rotated for 90 ° or 180 ° every 7 days.

In case of heavy rain and heavy snow, the time for kiln rotation specified above shall be halved. If the temperature of kiln shell is above 200 ℃, it is necessary to rotate the kiln slowly and continuously. At the same time, pay attention to the lubrication condition of each supporting roller bush. The continuous slow running time should not exceed 30 minutes, otherwise, it is necessary to spray oil on each supporting roller Bush mouth manually (the supporting roller Bush is lubricated intermittently to avoid tile burning). In order to prevent the deformation of the refractory lining after the new lining is built in the kiln, it is necessary to reduce the frequency of rotary kiln every 7 days or so 1 / 4 turn of rotary kiln.

2. Thermal insulation of rotary kiln shell in winter

Making thermal insulation quilt: the size of the thermal insulation quilt is determined according to the diameter and length of the cylinder;

Tracing tape laying (or electric blanket): before the cotton quilt is wrapped, the tracing tape is evenly wound on the cylinder, with a spacing of 500-1000mm. According to the length of the cylinder, 3-4 sections are reserved to connect the power connector;

Thermal insulation quilt laying: after the construction of heat tracing belt is completed, the thermal insulation quilt is wrapped on the cylinder.

During construction, pay attention not to crush or damage the heat tracing belt, so as to avoid short circuit of the heat tracing belt. After one heat preservation sheet is wrapped, the second heat preservation sheet will be wrapped until the whole cylinder is completely wrapped (the second and third gear rooms will be focused according to the enterprise's own situation). Crane with construction, progress block, high efficiency. Generally, after the kiln is ignited and heated, the thermal insulation quilt is removed in order, stacked neatly and stored in the warehouse for later use.

3. The inner surface of the cylinder is lined with stainless steel plate to avoid direct contact between the inner wall of the cylinder and the refractory brick.

4. The surface of the cylinder is pasted with high temperature resistant insulation felt.