Application:
Active lime burnt in the rotary kiln is mainly used for desulfurization projects like building materials，steel factory，ferroalloy plant，power plant，acetylene plant，paper factory etc.

Working principle:
Limestone that stored in the bunker are lifted by elevator and transported to the bunker on the top of the preheater. There are two silometers controlling the volume of adding materials, and through tremie pipe, the limestone uniformly fill in each room of the preheater. Heated by the smoke of 1150°C, the temperature of the limestone in the preheater is up to about 900°C. About 30% are decomposed and are pushed to the kiln by hydraulic rod. The limestones in the kiln are decomposed to be calcium and carbon dioxide. The decomposed go to the cooler, and when the temperature goes down to 100°C ,they are discharged. Hot air of 600°C enter the kiln and have a mixed combustion with coal gas. Adding cold air to push the waste gas to the bag filter through draught fan, and finally the waste gas go to the chimney through exhaust fan. The limes discharged from the cooler are carried to the finished-parts storage through vibration feeding machine, chain bucket conveyer, bucket elevator and belt conveyer.

Characteristics:  
1. With advanced technology, vertical preheater with low pressure loss effectively improve the preheating effect. For the preheated limestone，the decomposition rate of going into rotary kiln can reach 20—25% and limestone granularity of 10-15mm can be directly used.
2. The reliable sealing of combined scale on both sides of the rotary kiln，make the Air-leakage coefficient less than 10%. Composite refractory materials are used to reduce radiant heat loss.
3. Using vertical preheater in the shape of circle or square which could be filled and ventilated in partition, it makes the lime temperature in the cooler 800℃which is easy to transport ,store, and makes the secondary kiln air preheated to 700℃. In this way, it decreases the moving parts and special materials, and achieves the goal of recycling.

Main parameters