As one of the three pillars of the Cement production building Cement production materials industry, cement enterprises are one of the main pillars of the building materials industry. With the rapid development of China's economy, the AC500 increasing AC500 demand AC500 for cement in all walks of life. On the one hand, the total cement ABB production ABB cannot ABB meet the demand, especially the quality of cement is in short supply; on the other hand, although the Chinese cement production country, but most of the existing product line is used in the backward production technology, energy waste and environmental pollution, the need to eliminate. At present, the major domestic and foreign enterprises in China to build large-scale cement dry kiln cement production line, which provides a hitherto unknown opportunity for the development of the cement industry. ABB has prepared the best industrial automation solution for your cement production line to help you build an international advanced level, high output, low consumption, environmentally friendly and efficient production line.
2 brief introduction of cement production process
In general, the cement industry is the production of Portland cement, Portland cement is a fine, usually gray powder, which is composed of calcium (from limestone), silicate, aluminate and ferrite (clay). In a cement factory, the main process of the cement production process is made of raw material after crushing and grinding of raw materials, and then put the raw material into the furnace with the fuel calcination mature material, the amount of clinker and gypsum mixed ground made of cement, after mine mining, raw material crushing, drying, grinding clay and the clinker cooling, clinker, cement grinding and packing and other processes
In a word, the production process can be summarized as "three grinding and one kiln", which can be divided into four steps:
1, preparation of raw materials: the calcareous material, clay material and a small amount of correction material after crushing according to a certain proportion, grinding and deployment of raw material ingredients suitable, uniform quality.
2, the pulverized coal preparation: cement calcining the coal, must be prepared to provide the required size of pulverized coal, pulverized coal combustion, in order to get the full combustion, the combustion reaction ability enough.
3, clinker calcination: the diameter of the spherical agglomeration of clinker must be in the range of 0.32-5.0cm, and they are produced in the chemical reaction between the raw materials. The raw material on the cement kiln calcination to partial melting in Portland cement clinker and clinker silo to store.
4, cement grinding and clinker factory: the gypsum and mixed materials or additives for common ground cement, and packaging factory. The grinding process in a closed system, the system is equipped with an air separator used to separate the particles according to the size of the cement, the ground material is not completely re sent through the system.
3 design analysis
Through the introduction of the process, it is not difficult to see that this is a typical sequential control project (raw materials warehousing, transportation, cement grinding cement storage and packaging system). We can through the control of the object of each operation of the equipment in motor starting and stopping and reversing control, and a variety of alarm collection and programming instructions, switch signal and analog signal to realize the automation of process control.
The production line main equipment control, monitor, alarm and print management function by the control room control hardware implementation, 3 field station distribution in raw material grinding, kiln and kiln head, between the station and the process control room by data communication system to provide two-way information processing and information transmission.
According to the control requirements are divided into the following main functions:
The data acquisition function;
L switch control function;
The sequence control function;
4 system configuration
The system consists of process control station, operator station, engineer station and communication system (ProfiBus, DP/PA Modbus).
The function of AC500 system PLC is flexible, and its expansibility is strong. Traditional PLC products of small, medium and large size of the software and hardware differences are very large, the system has a limited development. And we AC500 only through 3, 4 kinds of different memory and speed of the CPU central processing unit can achieve a comprehensive upgrade of the system, so that can protect the customer's existing investment
Each control station of cement production is extremely dispersed, and the security of the system depends largely on the stability of the control network. The design and adoption of the redundant optical fiber ring network technology makes the process control network extremely reliable, which greatly improves the safety factor of the whole system.
Level 1 - monitoring management
The operation station and engineer station of central control room. Use industrial control computer, IP TCP/ Industrial Ethernet and PLC system communication, the implementation of centralized control. Through the industrial control configuration software, real-time monitoring of the entire production line process parameters change, equipment operation, fault, etc., at the same time, responsible for daily report printing, accident printing and data records, etc..
Second level process control
The control system of each subsystem or whole set of equipment is realized by the system. The AC500 PLC system as the control core, according to the field configuration of substation. The flow, pressure, temperature, electric machine and other parameters were collected and controlled by FBP distributed extended I/O communication.
Third level - single place control
By the field electrical control system. S500 company's ABB series product composition distribution I/O, collect the field parameters, the implementation of the first level PLC master control commands.
5 concluding remarks
Based on the research results of this paper, the technical scheme has been implemented in a cement production line in Shanxi. Because of using the method of computer control technology and PLC control technology combined, greatly improving the production efficiency of the cement production system, reduce the labor intensity of workers, improve the management level of automation system, effectively prevent the occurrence of the accident, but also saves a lot of money for the company.