Introduction to main equipment of cement production line

A series of equipment and special processes for cement production form a cement production line. The main raw material for cement production is limestone. The cement production line is mainly composed of crushing and pre-homogenization, raw meal preparation and homogenization, preheating and decomposition, cement clinker burning, cement grinding, cement packaging and other technological processes.

Introduction to main equipment of cement production line

The main equipment used in the cement production line includes: conveying equipment, belt conveyor, feeder, cement production line crusher, pulverizer, quantitative feeding scale, dust collector, roller press, ball mill, elevator, rotary kiln, dryer, air conveying chute, air compressor, powder concentrator, FU chain conveyor, chain bucket machine, grate cooler, kiln head cover, coal injection pipe, cyclone preheater, packaging machine and other equipment.

Cement ball mill: cement ball mill is the key equipment for crushing materials after crushing. It is widely used in cement and silicate products. The main shaft of the cement mill is self-aligned to ensure the normal operation of the rotary part of the cement mill. The lubrication mode of the cement mill is oil scoop, oil ring, and automatic oil station oil supply lubrication. All three forms can ensure the good lubrication of the cement mill. Except for the rod mill, the bearings used in the cement mill are generally equipped with cooling channels for water cooling to ensure the good working conditions of the cement mill bearings.

Cement rotary kiln: the cement rotary kiln can grind the cement raw material grinded by the grinding equipment, and the cement production line can be fired into cement clinker at the extremely high temperature of the rotary kiln, which can be divided into dry production cement kiln and wet production cement kiln. The cement rotary kiln is composed of cylinder, supporting device, supporting device with retaining wheel, transmission device, movable kiln head, kiln tail sealing device, combustion device and other components. The rotary kiln has a simple structure, Reliable operation and easy control of production process. The cement mechanical cement rotary kiln equipment produced by our company uses new wireless communication technology to transmit the temperature data measured by thermocouples to the operation room for display. Kiln temperature transmitter is powered by battery and can collect multiple thermocouple signals at the same time. It is installed on the kiln body and rotates with the cylinder. Due to the thermal insulation measures, it can withstand the radiation high temperature of the cylinder above 300 ℃, and is resistant to rain, sun and vibration. The kiln temperature receiver is installed in the operation room to directly display the temperature in the kiln, and has 4-20mA output, which can be sent to the computer or other instruments for display. This set of equipment is not only simple in structure, convenient in installation, reliable in operation, economical and practical, but also accurate and stable in data, with less maintenance and long service life. It is a good calcining equipment for cement production line and cement machinery.

Dryer: The dryer has strong adaptability to materials, can dry various materials, and the equipment operation is simple and reliable, so it is widely used.

Cyclone preheater: Cyclone preheater is suitable for supporting use of various kiln types. Based on the transformation and digestion of the main equipment imported from Kawasaki, Japan, with a daily output of 800 tons and 1000 tons of cement clinker, a five-stage suspension preheater with a daily output of 500 tons and 2000 tons with a decomposer has been developed. The preheater can be widely used in the construction and reconstruction of equipment in large, medium and small cement plants.

Grate cooler: Grate cooler is a kind of quench type cement production line cooler. Its principle is: use a blower to quench the layered clinker laid on the grate plate, so that the clinker temperature drops from 1200 ℃ to below 100 ℃, and a large amount of cooled waste gas is removed into the kiln for secondary air.

Process flow of cement production line

Process flow of cement production line The process of cement production line is "two grinding and one burning". The cement production line includes raw material preparation (raw material grinding), clinker calcination and cement grinding

1. Crushing and pre-homogenization of materials

The large stones are uniformly sent to the jaw crusher for coarse crushing by the vibrating feeder through the silo, and the coarse crushed stones from the cement production line are sent to the impact crusher by the belt conveyor for further crushing. The crushing of limestone plays an important role in the material crushing of cement machinery.

Raw material prehomogenization prehomogenization technology is to use scientific stacking and reclaiming technology to realize the preliminary homogenization of raw materials during the storage and retrieval of raw materials, so that the raw material storage yard has the functions of storage and homogenization at the same time.

2. Preparation of cement raw meal

In the process of cement production, at least 3 tons of materials shall be grinded for each ton of Portland cement production equipment, including various raw materials, fuels, clinker, mixtures and gypsum. According to statistics, the power required for the grinding operation of dry-process cement production line accounts for more than 60% of the power of the whole plant, of which raw material grinding accounts for more than 30%, coal grinding accounts for about 3%, and cement grinding accounts for about 40%. Therefore, reasonable selection of grinding equipment and process flow, optimization of process parameters, correct operation and control of operation system are of great significance to ensure product quality and reduce energy consumption.

3. Raw meal homogenization

During the production of new dry process cement, stabilizing the composition of raw meal entering the pit is the premise of stabilizing the thermal system of clinker burning, and the raw meal homogenization system plays a second role in stabilizing the composition of raw meal entering the pit.

4. Preheat decomposition

Cement machinery completes the preheating and partial decomposition of raw meal by preheater, replacing some functions of rotary kiln, so as to shorten the length of kiln return, and at the same time make the process of gas and material heat exchange in the kiln in the state of accumulation, and move it to the suspended state in the preheater, so that raw meal can be fully mixed with the hot gas discharged from the kiln, which increases the contact area of gas and material, the heat transfer speed is fast, and the heat exchange efficiency is high, so as to improve the production efficiency of the kiln system The purpose of reducing the heat consumption of clinker burning.

(1) Material dispersion

80% of the heat exchange is conducted in the inlet pipe. The raw material fed into the preheater pipe, under the impact of the high speed rising air flow, will turn up and move with the air flow, and will be dispersed at the same time.

(2) Separation of gas and solid

When the airflow carries the powder into the cyclone, it is forced to rotate and flow in the annular space between the cyclone cylinder and the inner cylinder (exhaust pipe), and it moves downward while rotating, from the cylinder to the cone, which can extend to the end of the cone, and then rotates upward to be discharged by the exhaust pipe.

(3) Predecomposition

The emergence of pre-decomposition technology is a technological leap in the calcination process of cement equipment. It is to add a decomposing furnace between the preheater and the rotary kiln, use the rising flue at the kiln end, and install a fuel injection device, so that the exothermic process of fuel combustion and the endothermic process of carbonate decomposition of raw meal can be rapidly carried out in the decomposing furnace in the suspended or fluidized state, so that the decomposition rate of raw meal into the kiln can be increased to more than 90%. Move the original carbonate decomposition task in the rotary kiln to the decomposition furnace; Most of the fuel is added from the calciner, and a small part is added from the kiln head, which reduces the heat load of the calcination zone in the kiln, prolongs the service life of the lining, and is conducive to large-scale production; Because the fuel and raw meal are mixed evenly, the fuel combustion heat is transferred to the material in time, which optimizes the combustion, heat exchange and carbonate decomposition process. Therefore, it has a series of excellent performances and characteristics such as high quality, high efficiency and low consumption.

5. Burning of cement clinker

After the raw meal is preheated and pre-decomposed in the cyclone preheater, the next step is to enter the rotary kiln for clinker burning.

In the rotary kiln, carbonates are further rapidly decomposed and a series of solid phase reactions occur to generate equivalent minerals in cement clinker. As the temperature of the material rises, the minerals will become liquid phase, and those dissolved in the liquid phase will react to generate a large amount (clinker). After the clinker is burnt, the temperature begins to decrease. After that, the cement clinker cooler will cool the high-temperature clinker discharged from the rotary kiln to the temperature that can be borne by the downstream conveying, storage and cement machinery, and recover the sensible heat of high-temperature clinker to improve the thermal efficiency and clinker quality of the system.

6. Cement grinding

Cement machinery is the post-process of cement manufacturing and also a process with high power consumption. Its main function is to grind the cement clinker (and gelling agent, performance regulating material, etc.) to a suitable particle size (expressed by fineness, specific surface area, etc.), form a certain particle size distribution, increase its hydration area, accelerate the hydration rate, and meet the requirements of cement paste setting and hardening.

7. Cement packaging

Cement is delivered in bags and bulk.