The clinker cement production line is used to implement the production process of assembling and transporting cement. The adoption of this new process ensures that the quality of clinker produced by dry method is not inferior to that produced by wet method, and the power consumption is also reduced, which has become a trend in the development of cement industry in various countries.

In the production process of clinker cement, at least 3 tons of materials (including various raw materials, fuels, clinker, mixtures, and gypsum) need to be ground for every 1 ton of Portland cement produced. According to statistics, the power consumption required for grinding operations in dry cement production lines accounts for more than 60% of the total power consumption of the plant, with raw material grinding accounting for more than 30%, coal grinding accounting for about 3%, and cement grinding accounting for about 40%. Therefore, reasonable selection of grinding equipment and process flow, optimization of process parameters, correct operation, and control of operating systems are of great significance for ensuring product quality and reducing energy consumption.

Working principle of clinker cement production line:

The electric motor drives the grinding disc to rotate through a reduction device, and the material falls into the center of the grinding disc through a locking feeding device and a discharge chute. Under the action of centrifugal force, it is thrown towards the edge of the grinding disc and crushed by the grinding rollers. The crushed material overflows from the edge of the grinding disc and is dried by the high-speed upward hot air flow from the nozzle. Depending on the speed of the air flow, some of the material is carried into the high-efficiency powder separator by the air flow. The coarse powder is separated and returned to the grinding disc for re grinding; Fine powder flows out of the mill with the air and is collected in the dust collection device of the system, which is the product. Coarse particles that are not carried by the hot air flow overflow the grinding disc and are fed into the powder mill by the external circulation bucket elevator. The coarse particles fall back into the grinding disc and are squeezed and ground again.

1. Homogenization of raw materials

Basic introduction
In the process of new dry cement production, the stable raw material composition is the premise of the stable clinker firing thermal system, and the raw material homogenization system plays the last role of the stable raw material composition.
Principle of homogenization
The use of air mixing, gravity action, produce a “funnel effect”, so that raw powder in the downward unloading, as far as possible to cut multiple layers of material surface, fully mixed. Different fluidized air is used to make the parallel material surface in the warehouse have different size of fluidization expansion, some areas of discharge, and some areas of fluidization, so that the material surface in the warehouse will tilt, and radial mixing and homogenization will be carried out.

2. Preheat decomposition

course
The preheating and partial decomposition of raw materials are completed by the preheater, replacing part of the function of the rotary kiln, so as to shorten the length of the return kiln. At the same time, the gas heat transfer process in the kiln is carried out in the accumulation state, and the process is carried out in the suspended state of the preheater, so that the raw materials can be fully mixed with the hot gas discharged in the kiln, and the contact area of the gas and material is increased, the heat transfer speed is fast, and the heat exchange efficiency is high. The purpose is to improve the production efficiency of kiln system and reduce the heat consumption of clinker firing.
Working principle
The main function of the preheater is to make full use of the waste gas and residual heat from the rotary kiln and the decomposition furnace to heat the raw material, so as to preheat the raw material and decompose part of the carbonate. In order to maximize the gas-solid heat transfer efficiency and achieve the high quality, high yield and low consumption of the whole calcining system, it is necessary to have three functions: uniform gas-solid dispersion, rapid heat transfer and efficient separation.
(1) Material dispersion
80% of the heat transfer is carried out in the inlet pipe. When the raw material is fed into the preheater pipe, under the impact of the high speed updraft, the material turns upward to move with the airflow and is dispersed at the same time.
(2) gas-solid separation
When the airflow carries the powder into the cyclone, it is forced to do rotating flow in the annular space between the cyclone cylinder and the inner cylinder (exhaust pipe), and while rotating, it moves downward, from the cylinder to the cone, which can be extended to the end of the cone, and then turns upward and rises, and is discharged by the exhaust pipe.
(3) Pre-decomposition
The emergence of predecomposition technology is a technological leap in cement calcining process. It is to add a decomposition furnace between the preheater and the rotary kiln, use the kiln tail rising flue, and set a fuel injection device, so that the heat release process of fuel combustion and the heat absorption process of carbonate decomposition of raw materials are carried out rapidly in the decomposition furnace in a suspended state or a fluidized state, so that the decomposition rate of raw materials into the kiln is increased to more than 90%. The carbonate decomposition task originally carried out in the rotary kiln is moved to the decomposition furnace. Most of the fuel is added from the calcination furnace, and a small part is added from the kiln head, which reduces the heat load of the calcination zone in the kiln, prolongs the life of the lining, and is conducive to large-scale production. Because the fuel and raw material are mixed evenly, the fuel combustion heat is transferred to the material in time, so that the combustion, heat exchange and carbonate decomposition process are optimized. Therefore, it has a series of excellent performance and characteristics such as high quality, high efficiency and low consumption.

3. Clinker burning

After the raw material is preheated and predecomposed in the cyclone preheater, the next step is to enter the rotary kiln for clinker firing.
In the rotary kiln, the carbonate is further rapidly decomposed and a series of solid reactions occur to produce minerals in the cement clinker. As the temperature of the material increases, the mineral will become a liquid phase, dissolve in the liquid phase and react to produce a large amount (clinker). After the clinker is fired, the temperature begins to drop. Finally, the high temperature clinker discharged from the rotary kiln is cooled by the cement clinker cooler to the temperature that the downstream conveying, storage and cement mill can withstand, and at the same time, the sensible heat of the high temperature clinker is recovered to improve the thermal efficiency and clinker quality of the system.

4. Cement grinding

Cement grinding is the final process of cement manufacturing and the process that consumes the most electricity. Its main function is to grind the cement clinker (and gelling agent, performance adjustment materials, etc.) to the appropriate particle size (expressed in fineness, specific surface area, etc.) to form a certain particle composition, increase its hydration area, accelerate hydration speed, and meet the requirements of cement slurry condensation and hardening.