Production of Lime and Lime Stone Production in Sri Lanka



Preheater is one host device of the active lime production, and its main function is to sent limestone from the upper part to the body of preheater, while using high-temperature exhaust gas (950--1100 degrees Celsius) discharged from the calcinations kiln to make heat exchange, and the preheat the materials evenly into 900 degrees Celsius in the preheater. After preheating, there is 30% CaCO3 will decompose and then pushed into rotary kiln for burning by the hydraulic push rod. So such a calcinations process not only shorten the time of limestone burning in the kiln, but also get a high degree of the active lime.





The Features of Preheater:
1, the upper feeding system: Includes the upper hopper, the next material possession, the next feeding method and structure can guarantee to the pre-heater of the body feeding to achieve security when closed, so that the cold air from outside can not enter into the Preheater, and feeding can make use of valve rod to achieve continuous or intermittent feeding.
2, Preheater body: It is to ensure that material preheated to 900 degrees Celsius of the most important part, it is by the warm room, hanging devices and brick lining (which does not belong to the scope of design and manufacturing equipment) and other parts. That part of the structure of most of metal structures, part of the material according to the need to use a heat-resistant steel, heat-resistant steel to 1100 degrees celsius in 1000 to work under high temperatures. In addition, the refractory bricks lining structure, novel design, sealing is good, can guarantee the material in pre-heater evenly and achieve pre-heating temperature preheating.
3, pusher devices: Mainly Tuitou, framework, and connecting rods and other parts of Tuitou using heat-resistant steel casting or welded together, can withstand high temperatures, using electronic control and hydraulic systems can be by putting the various hydraulic automatic control program to achieve sequential pusher.
4, the hydraulic system: Includes tanks, pumps, motors, solenoid valves, hydraulic tubing, etc., his main role is to control the pusher device to push the completion of material movement.
5, bottom feeding room: The main include slide tube, feeding the main room, feeding slip mouth and so on, its main role is to import the materials after preheating rotary kiln calcination.
6, Framework: It includes columns and ring beam and so on, the main role is to carry The upper part of the structure.






Working Principle:
The Working Principle Of preheater: According to the place of Preheater in rotary kiln system, and negative pressure working principle of Preheater. Heat emission is heat convective, the material and air is convection movement. When the raw materials feeding into the preheater, under the negative pressure condition, to prevent cold air into the preheater, the inlet of raw materials must take effective seal. This is to ensure the effective use of heat and material preheating effect. The standard of preheating quality in the preheater, is the feeding room's temperature which is in the bottom of preheater. Kiln temperature is: Detected by thermocouple in the side wall of feeding room, including the flame radiation and air temperature. It reflects the firing temperature when feed into kiln, but also the degree of feedback the final warm-up temperature of the material. To Preheater, Truly reflects the effective temperature of the material is outlet temperature of the Preheater top. Temperature control on this point is more important than the end of the rotary kiln temperature control. Within preheater, materials after preheating and pre-decomposition, pushing out from Preheater to Rotary kiln by hydraulic plunger device.