Analysis And Solution To The Vibration Of Rotary Kiln

Rotary kiln is the most important main machine equipment of cement production line. It is the place where the material is transformed from raw material to clinker. It is the place with the highest temperature of production line.

The calcination temperature of the kiln materials is generally 1400-1450 ℃, and the flame temperature in the kiln can reach 1600-1800 ℃ or higher.

In order to protect the rotary kiln barrel equipment and reduce the surface heat dissipation of the rotary kiln, a masonry is required in the rotary kiln.

The fixed thickness of refractory materials, which leads to the increase of the load of the kiln equipment body, and the kiln shell with certain thickness in the firing zone in the rotary kiln will also lead to the increase of the load on the kiln body.

Because of the high temperature, high load, fast speed and long length of rotary kiln, the probability of vibration is greatly increased, and the vibration degree and performance of rotary kiln are also varied.

The causes of vibration can be classified into two categories: process reason and equipment reason. Today we talk about the vibration of kiln body caused by the process and the treatment method.

The periodic vibration of rotary kiln will be caused by the non straight or deformed kiln barrel. The following briefly introduces several technological reasons and treatment methods that cause the vibration of rotary kiln.

1. Normal shutdown and restart

After a long time of stopping or temporary emergency stop, the rotary kiln will have periodic vibration less than half circle after the ignition or recovery.

In case of serious, the other supporting wheels (if not, multiple supporting wheels) and the wheel belt do not contact with the wheel belt in a certain range, and the current of the main transmission motor of the kiln will also fluctuate with the vibration.

In serious cases, the large gear and the transmission pinion will also vibrate synchronously. After the kiln is running for a period of time (generally within 3D), the vibration of rotary kiln gradually reduces until it returns to normal.

1.1 main reasons

The main reasons for this kind of quietly state are as follows: the time of feeding and auxiliary transmission after the rotary kiln is stopped is too short, the interval between the two kilns is too long in hot kiln, and the angle of each turning over is incorrect; after a long time of stopping, the angle of he kiln or kiln turning is not correct during the period of stopping; the rotary kiln fails to timely transfer auxiliary transmission when the rotary kiln is in emergency stop.

1.2 treatment method

If the rotary kiln ignites or returns to feeding operation within 3 days, the vibration will gradually reduce until it is restored to normal without any treatment. When the rotary kiln vibration is not fully restored to normal, the rotary kiln speed shall be controlled in process operation, and it cannot be accelerated blindly.

It should be noted that when the kiln stops or stops for a long time, it is necessary to correctly transfer and turn over the kiln according to the provisions in the operation manual of the rotary kiln, otherwise, the kiln body may be fatigue fracture.

2. Stop kiln and restart in case of failure

After the kiln is stopped in accident, after the kiln is ignited or restored, the rotary kiln will have periodic vibration less than half circle. In case of serious situation, the other supporting wheels (sometimes multiple supporting wheels) and the wheel belt will not contact with the wheel belt in a certain range.

The current of the main motor of the kiln will also be synchronized with the vibration. In serious cases, the large tooth ring and the transmission pinion of the rotary kiln will also vibrate synchronously.

When the rotary kiln is running for a certain time (more than 3D), although the vibration of the kiln has been reduced, the vibration value is still beyond the allowable range, and the vibration can not be eliminated completely by many adjustment methods.

2.1 main reasons

There are three main reasons for this situation: when the rotary kiln falls off bricks in large area or the large area red kiln stops coal and stops fire in time, it does not properly transfer and turn over the kiln in strict accordance with the provisions of the operation manual of the rotary kiln, which causes the uneven expansion and contraction of the barrel of the rotary kiln and serious bending deformation;

In the severe climate of heavy wind and heavy rain, the kiln was stopped accident, and the kiln was not transmitted and turned over in time after the kiln was stopped, which caused the uneven shrinkage of the kiln barrel and serious bending deformation; the kiln stopped in the rotary kiln stage and never turned over after the kiln was stopped.

2.2 treatment method

If it is a large area brick dropping or large-area red kiln, stop coal and stop fire in time, and then turn over the kiln to extend the cold kiln time as much as possible; during the severe weather with strong wind and heavy rain, it is necessary to ensure that the standby power supply can be used at any time, and the standby power supply shall be maintained and maintained in good condition.

If the barrel of rotary kiln is bent and deformed, especially if the center line of supporting ring of gear 1, 2 and 3 is not straight at the same time, it should be adjusted first.

When stopping the kiln to build refractory bricks, the minimum point of lead pressure data should be turned to the top of the rotary kiln (i.e. the arch is above).

Especially when the kiln is stopped, the kiln cannot be turned over for several days. Depending on the weight of the kiln, the bending deformation of the rotary kiln can be reduced.

At the initial ignition of rotary kiln, turn the maximum point of lead pressure data value to the top of rotary kiln (i.e. arch is below). Under the high temperature condition, the maximum point of the lead pressure data is turned to the top of the rotary kiln for 10-15min, and then it is operated for 3-5min by auxiliary transmission.

After repeated several times, the vibration of the kiln will gradually reduce. If the large area of brick falling or large area red kiln of rotary kiln causes serious deformation of the barrel, after the above adjustment is invalid, it is necessary to consider replacing the seriously deformed kiln shell.

3. Thermal expansion of cylinder and wheel belt

During the operation of rotary kiln, the third gear idler vibrates, and the vibration value increases gradually from small to small, sometimes after a period of time, the vibration value decreases from large to normal;

The vibration periodicity is not obvious or irregular. The temperature measurement data of the cylinder scanner (or the hand-held thermometer) shows that the temperature of the second wheel belt is significantly higher.

When the hand-held thermometer is used to check the wheel belt backing plate, the temperature is significantly higher than that of the adjacent cylinder, and the temperature of the second gear supporting wheel pad is increased.

When checking the slip between the wheel belt and the backing plate, it is found that the temperature is significantly reduced, and in serious cases, it is found that the sliding amount of the wheel belt and the backing plate is significantly reduced, and in serious cases No slip or even the belt may lock the backing plate.

3.1 main reasons

The main reasons for this situation are: the second wheel belt is thin, the process is improper, the flame moves backward, and the high temperature zone is formed at the second wheel belt, which causes the expansion of the kiln barrel and wheel belt temperature; the fire brick at the second wheel belt is very thin, and the kiln barrel and wheel belt temperature in this section will expand after the temperature increases.

3.2 treatment method

If the vibration value increases gradually from small to small, the vibration value decreases from large to normal after a period of time, generally due to the formation of high temperature zone at the wheel belt due to improper process operation, which results in the thermal expansion of the cylinder and wheel belt.

In the process operation, the flame length and strength should be controlled, and the external cooling of the cylinder should be strengthened in the high temperature area to avoid local high temperature at the second gear wheel belt.

If the kiln vibration is gradually reduced until it is restored to normal, no treatment can be done; if the kiln vibration is gradually reduced until it is restored to normal, no treatment can be done; If the vibration value increases gradually from small to small, it can not be restored to normal after a certain time of operation.

Generally, it is caused by the thermal expansion of the cylinder and wheel belt caused by the serious ultra thin refractory brick at the wheel belt. In the process operation, the flame length and strength shall be controlled, the temperature of the local high temperature zone at the second gear wheel belt shall bRotary kiln is the most important main machine equipment of cement production line.

It is the place where the material is transformed from raw material to clinker. It is the place with the highest temperature of production line. The calcination temperature of the kiln materials is generally 1400-1450 ℃, and the flame temperature in the kiln can reach 1600-1800 ℃ or higher.

In order to protect the rotary kiln barrel equipment and reduce the surface heat dissipation of the rotary kiln, a masonry is required in the rotary kiln The fixed thickness of refractory materials, which leads to the increase of the load of the kiln equipment body, and the kiln shell with certain thickness in the firing zone in the rotary kiln will also lead to the increase of the load on the kiln body.

Because of the high temperature, high load, fast speed and long length of rotary kiln, the probability of vibration is greatly increased, and the vibration degree and performance of rotary kiln are also varied. The causes of vibration can be classified into two categories: process reason and equipment reason. Today we talk about the vibration of kiln body caused by the process and the treatment method.

The periodic vibration of rotary kiln will be caused by the non straight or deformed kiln barrel. The following briefly introduces several technological reasons and treatment methods that cause the vibration of rotary kiln.

1. Normal shutdown and restart

After a long time of stopping or temporary emergency stop, the rotary kiln will have periodic vibration less than half circle after the ignition or recovery. In case of serious, the other supporting wheels (if not, multiple supporting wheels) and the wheel belt do not contact with the wheel belt in a certain range, and the current of the main transmission motor of the kiln will also fluctuate with the vibration.

In serious cases, the large gear and the transmission pinion will also vibrate synchronously. After the kiln is running for a period of time (generally within 3D), the vibration of rotary kiln gradually reduces until it returns to normal.

1.1 main reasons

The main reasons for this kind of quietly state are as follows: the time of feeding and auxiliary transmission after the rotary kiln is stopped is too short, the interval between the two kilns is too long in hot kiln, and the angle of each turning over is incorrect;

after a long time of stopping, the angle of he kiln or kiln turning is not correct during the period of stopping; the rotary kiln fails to timely transfer auxiliary transmission when the rotary kiln is in emergency stop.

1.2 treatment method

If the rotary kiln ignites or returns to feeding operation within 3 days, the vibration will gradually reduce until it is restored to normal without any treatment.

When the rotary kiln vibration is not fully restored to normal, the rotary kiln speed shall be controlled in process operation, and it cannot be accelerated blindly.

It should be noted that when the kiln stops or stops for a long time, it is necessary to correctly transfer and turn over the kiln according to the provisions in the operation manual of the rotary kiln, otherwise, the kiln body may be fatigue fracture.

2. Stop kiln and restart in case of failure

After the kiln is stopped in accident, after the kiln is ignited or restored, the rotary kiln will have periodic vibration less than half circle.

In case of serious situation, the other supporting wheels (sometimes multiple supporting wheels) and the wheel belt will not contact with the wheel belt in a certain range.

The current of the main motor of the kiln will also be synchronized with the vibration. In serious cases, the large tooth ring and the transmission pinion of the rotary kiln will also vibrate synchronously.

When the rotary kiln is running for a certain time (more than 3D), although the vibration of the kiln has been reduced, the vibration value is still beyond the allowable range, and the vibration can not be eliminated completely by many adjustment methods.

2.1 main reasons

There are three main reasons for this situation:

when the rotary kiln falls off bricks in large area or the large area red kiln stops coal and stops fire in time, it does not properly transfer and turn over the kiln in strict accordance with the provisions of the operation manual of the rotary kiln, which causes the uneven expansion and contraction of the barrel of the rotary kiln and serious bending deformation;

In the severe climate of heavy wind and heavy rain, the kiln was stopped accident, and the kiln was not transmitted and turned over in time after the kiln was stopped, which caused the uneven shrinkage of the kiln barrel and serious bending deformation; the kiln stopped in the rotary kiln stage and never turned over after the kiln was stopped.

2.2 treatment method

If it is a large area brick dropping or large-area red kiln, stop coal and stop fire in time, and then turn over the kiln to extend the cold kiln time as much as possible;

During the severe weather with strong wind and heavy rain, it is necessary to ensure that the standby power supply can be used at any time, and the standby power supply shall be maintained and maintained in good condition.

If the barrel of rotary kiln is bent and deformed, especially if the center line of supporting ring of gear 1, 2 and 3 is not straight at the same time, it should be adjusted first.

When stopping the kiln to build refractory bricks, the minimum point of lead pressure data should be turned to the top of the rotary kiln (i.e. the arch is above). Especially when the kiln is stopped, the kiln cannot be turned over for several days.

Depending on the weight of the kiln, the bending deformation of the rotary kiln can be reduced. At the initial ignition of rotary kiln, turn the maximum point of lead pressure data value to the top of rotary kiln (i.e. arch is below).

Under the high temperature condition, the maximum point of the lead pressure data is turned to the top of the rotary kiln for 10-15min, and then it is operated for 3-5min by auxiliary transmission.

After repeated several times, the vibration of the kiln will gradually reduce. If the large area of brick falling or large area red kiln of rotary kiln causes serious deformation of the barrel, after the above adjustment is invalid, it is necessary to consider replacing the seriously deformed kiln shell.

3. Thermal expansion of cylinder and wheel belt

During the operation of rotary kiln, the third gear idler vibrates, and the vibration value increases gradually from small to small, sometimes after a period of time, the vibration value decreases from large to normal; The vibration periodicity is not obvious or irregular.

The temperature measurement data of the cylinder scanner (or the hand-held thermometer) shows that the temperature of the second wheel belt is significantly higher.

When the hand-held thermometer is used to check the wheel belt backing plate, the temperature is significantly higher than that of the adjacent cylinder, and the temperature of the second gear supporting wheel pad is increased.

When checking the slip between the wheel belt and the backing plate, it is found that the temperature is significantly reduced, and in serious cases, it is found that the sliding amount of the wheel belt and the backing plate is significantly reduced, and in serious cases No slip or even the belt may lock the backing plate.

3.1 main reasons

The main reasons for this situation are: the second wheel belt is thin, the process is improper, the flame moves backward, and the high temperature zone is formed at the second wheel belt,

which causes the expansion of the kiln barrel and wheel belt temperature; the fire brick at the second wheel belt is very thin, and the kiln barrel and wheel belt temperature in this section will expand after the temperature increases.

3.2 treatment method

If the vibration value increases gradually from small to small, the vibration value decreases from large to normal after a period of time, generally due to the formation of high temperature zone at the wheel belt due to improper process operation,

which results in the thermal expansion of the cylinder and wheel belt. In the process operation, the flame length and strength should be controlled, and the external cooling of the cylinder should be strengthened in the high temperature area to avoid local high temperature at the second gear wheel belt.

If the kiln vibration is gradually reduced until it is restored to normal, no treatment can be done; if the kiln vibration is gradually reduced until it is restored to normal, no treatment can be done; If the vibration value increases gradually from small to small, it can not be restored to normal after a certain time of operation.

Generally, it is caused by the thermal expansion of the cylinder and wheel belt caused by the serious ultra thin refractory brick at the wheel belt.

In the process operation, the flame length and strength shall be controlled, the temperature of the local high temperature zone at the second gear wheel belt shall be reduced, and the temperature of the cylinder shall be strictly controlled (it shall be guaranteed to be below 400 ℃).

If the temperature cannot be controlled, it shall be considered Stop kiln and replace refractory brick.e reduced, and the temperature of the cylinder shall be strictly controlled (it shall be guaranteed to be below 400 ℃).

If the temperature cannot be controlled, it shall be considered Stop kiln and replace refractory brick.