Rotary kiln refers to rotary calcining kiln (commonly known as rotary kiln), which belongs to building materials equipment. Rotary kiln can be divided into cement kiln, metallurgical chemical kiln and lime kiln according to different processing materials. The cement kiln is mainly used for calcining cement clinker, and it is divided into two types: cement kiln and wet kiln.
First, the classification of rotary kiln
Classification of rotary kiln: According to the external type, it can be divided into variable diameter rotary kiln and rotary kiln. It can be divided into cement rotary kiln, ceramsite rotary kiln, kaolin rotary kiln, lime rotary kiln, etc. according to the application. Differently divided into gas rotary kiln, coal rotary kiln, mixed fuel rotary kiln.
Second, the role of rotary kiln
1. During the beneficiation process, the rotary kiln is used to magnetize the lean iron ore to change the original weak magnetic properties of the ore to strong magnetic properties to facilitate magnetic separation.
2. In the chemical industry, the rotary kiln is used to produce soda, calcined phosphate fertilizer, and strontium sulfide. In the 1960s, LapPle et al. invented a new process for producing phosphoric acid from rotary kiln. The method has the advantages of low energy consumption, low power consumption, no use of sulfuric acid and availability of medium and low grade phosphate rock.
3. In terms of environmental protection, developed countries in the world have used cement kiln to burn hazardous waste and garbage for more than 20 years. This not only reduces waste and harmless waste, but also uses waste as fuel to save coal powder. Recycling of waste.
4. The whole production process of cement is summarized as “two mills and one burn”. Among them, “one burn” is the process of burning raw materials prepared by grinding and burning into clinker under the high temperature of rotary kiln. Therefore, the rotary kiln is the main engine in the production of cement, commonly known as the "heart" of the cement factory.
5, its technical performance and operation, to a large extent determines the quality, output and cost of the company's products. "As long as the big kiln turns, there are tens of millions." This folk song is a vivid description of the importance of the rotary kiln in production.
6. In the building materials industry, in addition to calcined cement clinker, rotary kiln is also used for calcining clay, limestone and slag drying; in the production of refractory materials, rotary kiln calcined raw materials are used to make the dimensional stability and strength increase. , re-formed.
Third, the structure of the rotary kiln
1, the kiln head part
The kiln head is the discharge part of the rotary kiln, the diameter is larger than the diameter of the rotary kiln, and the seal is realized by the stainless steel fish scales and the kiln body. The main components are the inspection port, the coal nozzle, the trolley, and the observation hole.
2, the kiln body part
It is the main body of a rotary kiln (rotary kiln), usually 30 to 150 meters long, cylindrical, with 3 to 5 rolling rings in the middle. The cylinders are mostly processed by the factory into 3~10 sections, which are welded by large trucks to the destination and welded. The rolling ring part is also commonly known as (the tire ring) cast from molten steel, and the kiln part of the rolling ring is slightly thicker than other parts of the kiln steel plate due to the bearing capacity. The supporting tug, which is also part of the kiln body and the rolling ring, is connected to the foundation and is the load-bearing pillar of the entire rotary kiln. Usually a set of rollers consisting of two rollers and two retaining wheels. The rotary kiln should be covered with refractory bricks during normal operation.
3, the kiln tail part
The kiln tail part is also an important part of the rotary kiln. The shape of the feed end is similar to that of a rotary kiln, which mainly undertakes feeding and sealing.
Fourth, rotary kiln support frame
1. The rotary kiln bracket can facilitate the lifting and hoisting of our rotary kiln equipment and facilitate transportation.
2. The support frame of the rotary kiln can make our rotary kiln equipment more sturdy, so that it will not shake when working, and stable production;
3. The support frame of the rotary kiln is mainly to fix our rotary kiln equipment, which can prevent the deformation of our rotary kiln equipment when it is used. Everyone knows that the rotary kiln equipment will be shaped if it is improperly operated, so it has such a role. .
Fifth, the device configuration of the rotary kiln
1, conveyor belt
Conveyor belt is the material conveying device of rotary kiln. In the course of use, various forms of damage often occur, such as: edge delamination, ulceration, defect and cracking; long distance longitudinal tear, deep scratch, hole, large area wear Covering the drum kit or peeling, the internal defects of the joint, etc. Among them, the longitudinal tear is the most urgent, the edge damage is the most common, the internal defects of the joint are difficult to avoid, and the service life after repair is most concerned.
2, preheating tower
Also called preheater is the equipment for the preliminary heating of the material by the residual heat of the exhaust gas discharged from the rotary kiln before entering the rotary kiln, mostly vertical structure. The principle is that the waste heat discharged from the tail of the rotary kiln is heated by the preheating tower filled with raw materials. Together with the preheating tower, it can effectively reduce energy consumption and improve the quality level of finished products.
3, cooling machine
The cooler and the preheater are the devices that quickly cool down after the rotary kiln material is fired. It looks like a small rotary kiln, but the diameter is smaller and shorter, no need to lay refractory bricks, and the inside is replaced by a lifting plate. The main role is to cool the finished product quickly.
The traditional high-temperature thermal vulcanization process has poor repairing effect on long-distance longitudinal tearing, long-distance edge festering, edge defect, and the rotary kiln is heavy and labor intensive. Foreign countries often use new materials to solve the problem of conveyor belt damage, Kester 90T high-curing rubber repair paste or Fusuoen rubber repair materials repair. 90T has excellent adhesion, adhesion to all rubber; excellent elasticity, tensile strength up to 300%; excellent anti-wear performance, wear resistance over heat-cured synthetic rubber; good anti-scattering performance, can be vertical or The top surface is applied to a thickness of 1 inch without scattering; 100% solids means no shrinkage, excellent chemical resistance, and resistance to a wide variety of chemical corrosion. Fawthorne is a new synthetic rubber product that can be used to repair conveyor belts simply, quickly and permanently. It has excellent wear resistance, impact resistance and long-term durability equivalent to extending the life of the conveyor belt.