The speed adjustment of the lime rotary kiln needs to be dynamically optimized in combination with process parameters, equipment status and material characteristics. Too fast a speed of the lime rotary kiln will have many negative effects on the calcination process, equipment life and operation stability, as shown below:

Deterioration of calcination process

1. Insufficient material residence time. Too high a speed will shorten the residence time of the material in the high temperature section (normally ≥30 minutes), resulting in insufficient decomposition of limestone, reduced activity and even raw burning.

2. Abnormal movement mode. Too fast a speed will cause the material to change from normal rolling to sliding or falling, reducing the contact area between the material and the hot flue gas, and reducing the thermal efficiency by 15%-20%.

3. Increased pulverization rate: Intensified sliding friction leads to an increase in limestone crushing rate and excessive dust emissions (an additional cyclone dust removal system is required).

Increased mechanical load

1. The wear rate of the support roller and wheel belt of the transmission system increases by 2-3 times, and the shear force of the gear increases, so alloy steel is required;

2. The vibration amplitude of the cylinder structure increases by 30%-50%, and the thickness of the cylinder steel plate under the wheel belt is required to be increased (normally ≥40mm);

3. The speed of the support roller of the lubrication system increases, resulting in the risk of lubricating oil film rupture, and high-viscosity synthetic lubricant (ISO VG 460) needs to be used instead

Increased risk of ring formation

1. When the material layer is too thin and the speed does not match the pushing time, the thickness of the material layer in the kiln is lower than the critical value (<200mm), and the powdered material melts in the high-temperature area to form ring formation.

2. Operational stability is destroyed. Frequent adjustment of the speed will disrupt the temperature field in the kiln, aggravate local high temperature (fluctuation ≥50℃), and accelerate the melting and bonding of low-melting-point impurities (such as Al₂O₃, Fe₂O₃).

Thermal system disturbance

1. The life of refractory materials is shortened, the surface temperature fluctuation of kiln lining is aggravated (from 250℃ to 400℃), the thermal stress of refractory bricks is increased, and the life is shortened by 30%-50%.

2. Abnormal energy consumption, the current of the main motor increases by 20%-30%, and the power consumption per ton of lime increases by 5-8kW·h.

Suggested control measures:

1. Gradual speed regulation: the core high temperature section is maintained at 1.5-2r/min, and the preheating zone can be increased to 2.5r/min (a matching frequency conversion control system is required);

2. Dynamic monitoring: install vibration sensors (range 0-10mm/s) to warn of mechanical failures in real time;

3. Process matching: the speed and slope (3%-4%), and the pushing frequency are adjusted in linkage to maintain the material layer thickness of 200-300mm