The lime preheater is one of the main engines of the active lime equipment. The main function of the lime preheater is to send the limestone materials sent from the upper part to the preheater. At the same time, the high-temperature waste gas (850 ℃) discharged after calcination in the kiln is used to evenly preheat the materials to more than 800 ℃ in the preheater. During the preheating process, 30% CaCO3 is decomposed in the preheater, and then pushed into the rotary kiln by the hydraulic pusher for calcination, Such calcination process can not only greatly shorten the calcination time of limestone in the kiln, but also obtain lime with high activity.

The lime preheater system is mainly composed of six parts:

1. Upper feeding system: it mainly includes upper silo and blanking pipe. The blanking method and structure can ensure the safe sealing when feeding into the preheater body, so that the external cold air cannot enter the preheating period, and the feeding can realize continuous or uninterrupted feeding with the help of bar valve.

2. Preheater body: it is the most important part to ensure the preheating of materials above 800 ℃. It is composed of preheating chamber, suspension device and refractory brick lining (this item does not belong to the scope of equipment design and manufacturing). The structure of this part is mostly metal components, and some materials are made of heat-resistant steel according to needs. The heat-resistant steel can work at a high temperature of 1000 ~ 1100 ℃. In addition, the refractory brick lining has novel structural design and good sealing, which can ensure that the materials can be preheated evenly in the preheater and reach the preheating temperature.

3. Pushing device: it mainly includes pushing head, frame, connecting rod and other parts. The pushing head is made of heat-resistant steel casting or welding and can withstand high temperature. With the help of electric control and hydraulic system, each hydraulic push rod can push materials in sequence according to the automatic control program.

4. Hydraulic system: mainly including oil tank, oil pump, motor, solenoid valve, hydraulic oil pipe, etc. Its main function is to control the pushing device and complete the pushing action.

5. Lower feeding chamber: it mainly includes chute, main body of feeding chamber, feeding chute, etc. its main function is to introduce preheated materials into rotary kiln for calcination.

6. Frame: it mainly includes column, ring beam, etc., which is mainly used to carry the superstructure of preheater.