Linyi Jinyong Kiln Construction Co., Ltd. specializes in the design and construction of dual chamber kilns. The following is an introduction to the design and construction features of 800 ton dual chamber lime kilns. Firstly, this type of kiln needs to have experience in the construction of 400 tons to 600 tons of dual chamber kilns in the early stage, with a 600 ton capacity double chamber kiln construction case, and is skilled in the overall structure and process technology debugging. The outer diameter of 800 tons/day dual chamber lime kilns is slightly larger than 600 tons, and the center distance is also expanded. The air intake system is improved, Add 3 reversing valves on the kiln top, and improve and optimize the process. Here is a brief introduction to the 800 ton double chamber lime kiln process.
Air system
There are three types of air used in the lime kiln: combustion air, lime cooling air, and spray gun cooling air, which are respectively transported to the kiln bore by their respective Roots blowers.
1 Combustion air After the combustion air comes out of the blower room, it is sent to the four combustion air/flue gas reversing valves on the kiln roof in two ways through the combustion air header. The sequential action of these four directional valves realizes the functional exchange of the air blowing and smoke exhaust states of the two kilns.
The combustion air is released into the atmosphere through the combustion air release valve during the reversing of the kiln chamber. At this time, the combustion air is no longer supplied to the kiln, and the kiln is in a pressure free state. Due to changes in the output of the lime kiln, it is necessary to supply combustion supporting air with varying flow rates into the kiln, which is achieved by changing the frequency of the blower motor and adjusting the number of fans opened. Combustion air is sent through pipelines to the four combustion air/flue gas reversing valves on the kiln roof, and then enters the kiln chamber through the reversing valve of the combustion chamber to participate in pulverized coal combustion.
Key technical features and innovation points
1. Adopting thermal design furnace type and refractory material parameters, the kiln has good thermal insulation performance, low surface temperature, and low overall energy consumption.
2. This engineering technology is used to carry out three-dimensional design in the early stage of the project, provide customers with satisfactory design schemes, and strictly control the construction quality and progress in the later construction management.
3. Strictly implement relevant national, industrial and local technical standards and specifications; Energy conservation and environmental design comply with national and local specifications.
4. The layout of the process flow is reasonable, meeting the requirements of the production process, and the production process is compact and smooth. The requirements of equipment operation, maintenance, and other disciplines are fully considered.
5. Coordinated overall planning and layout; Make full use of terrain conditions, use less land, and save investment; Pay attention to the direction of the wind, reduce environmental pollution, shorten the transportation distance within the factory, ensure smooth and orderly flow of people and logistics, meet production, safety, fire protection requirements, and leave room for expansion for future development, expansion, transformation, and other factors.
Shaft kiln calcination system
The limestone material weighed by the weighing hopper is loaded into the hopper car, which is lifted by a 5t winch to the top of the double chamber kiln. The limestone in the hopper car is added to the 7.5m3 silo on the top of the kiln. The material is fed to the reversible belt by the vibratory feeder, and then sent to the rotary hopper on each kiln bore by the reversible belt. The material is distributed by the rotary hopper by opening the kiln bore feeding ram. A level indicator is installed on the top of the kiln to display the level of materials in the kiln. Materials pass through the pre heating zone, calcination zone, and cooling zone in the kiln, and enter the kiln bottom silo through the pallet ash extractor and kiln bore discharge ram.
Thermal Principles
Double chamber kiln is an advanced lime calcining equipment, which has two vertical chambers and two connecting channels at the middle and lower parts of the kiln body to connect the two chambers. The calcination process has two main characteristics: concurrent flow and heat storage. The so-called concurrent flow refers to the downward flow of combustion products together with limestone during limestone calcination, which is conducive to calcining high-quality active lime. The so-called heat storage is that during the calcination of kiln chamber A, the calcined product - high-temperature flue gas enters kiln chamber B through two connecting channels at the middle and lower parts of the kiln chamber. After entering kiln chamber B, high-temperature flue gas flows upward to preheat the limestone in the preheated zone to a higher temperature. This process is equivalent to storing the heat of the flue gas in the preheated zone of kiln chamber B. The flue gas passing through kiln chamber B drops to a very low temperature and is discharged from the kiln chamber. This working principle fully utilizes the residual heat of flue gas, ensuring that this type of kiln has a high thermal efficiency. The functions of the two kilns for calcination and heat storage are interchangeable. That is, one kiln chamber is calcined and the other kiln chamber is used for heat storage. After 12 to 18 minutes, the function of the two kiln chambers is switched.