Energy-saving active lime rotary kiln

The energy-saving active lime rotary kiln is a new type of active lime special rotary kiln developed based on the calcination characteristics of limestone. This type of rotary kiln (optionally equipped with a vertical preheater and a vertical cooler to form an energy-saving rotary kiln calcination system) has the characteristics of high raw material utilization, complete calcination, uniform quality, good quality, large production capacity, high operating rate, energy saving and environmental protection, simple operation and long machine life.

Basic principles and thermal process of lime rotary kiln

Process flow:

(1) Raw material storage and transportation

Limestone with a particle size of 10 to 50 mm is transported to the plant area and piled in the material yard. Loaders are used for material yard operations. The loader loads the material with qualified particle size into the receiving trough set up in the material yard. The feeder feeds the material quantitatively under the receiving trough and feeds the stone to the high-angle conveyor, and then to the screening building. After screening, the limestone with qualified particle size is weighed and sent to the high-angle conveyor to the top silo of the preheater. The powdered material under the screen is sent to the storage yard by conveyor 3# and transported out regularly by forklift.

(2) Limestone calcination

The limestone calcination consists of a vertical preheater + rotary kiln + vertical cooler, with a production capacity of 100~1000t/d. The material is introduced into the preheater body from the top hopper of the preheater through the discharge chute. At the same time, the high-temperature flue gas introduced from the rotary kiln preheats the material to above 1000℃, causing partial decomposition of the limestone. The material is then pushed into the tail of the rotary kiln by the hydraulic push rod in sequence. After high-temperature calcination in the rotary kiln, it is unloaded into the cooler. The material is cooled by the cold air blown in by the fan to below the ambient temperature + 60℃ and discharged from the cooler. The air blown in by the cooler enters the rotary kiln as secondary air to participate in combustion.

(3) Finished product transportation

After being discharged from the cooler, the finished lime is transported to each finished lime storage via a chain conveyor, a bucket elevator, and a belt conveyor. The lower discharge valve of the lime silo is used to load lime from the silo into trucks or tankers for transport. Silos of varying sizes can be configured to meet customer storage requirements.

The finished product storage silos are circular, with two silos for 5-50mm finished products and one silo for finished products <5mm. Each silo holds approximately 800 tons.

Product Advantages

1. Providing an ideal, uniform temperature field to meet lime calcination requirements.

During the calcination process, the limestone in the rotary kiln undergoes both axial movement and radial tumbling. The high-temperature flames and hot air flow emitted by the rotary kiln burners heat the limestone through radiation, convection, and conduction. This results in uniform heating of the limestone, a lower overburn rate of lime, and improved lime quality.

2. High production capacity, high efficiency, and low heat consumption

The rotary kiln calcination system utilizes technological innovations such as a hydraulic throttle device, a high-precision metering plunger pump, a speed regulating valve, and contact-type graphite block sealing, resulting in stable performance, high output, and low energy consumption.

3. Flexible Control, Smooth Operation, and Environmentally Friendly

By adjusting parameters such as the preheater's pushing cycle, kiln speed, and air-to-coal ratio, production and quality can be easily and flexibly adjusted. The equipment operates smoothly, with a low failure rate and high availability. Because the rotary kiln operates at full negative pressure, the on-site environment is excellent and fully meets environmental requirements.

Lime rotary kiln technical parameters: