[Abstract]: This paper briefly introduces the process of aluminum hydroxide production, and carries out the process control system design and function realization of aluminum hydroxide production for this process. This system adopts the advanced SUPCON JX300XP DCS control system. Oxygen plant high white production control system is taken as an example to elaborate the control scheme of the system and the realization of the control system. After more than six months of on-site operation, remarkable economic benefits have been achieved, and the automation level of aluminum hydroxide production has been improved. Improve the level of enterprise automation. China Nonferrous Network.
[Keywords]: Aluminum hydroxide production DCS
1 Introduction China Aluminium Zhongzhou Branch is one of the alumina production bases under the China Aluminum Corporation. China Nonferrous Network. The Zhongzhou branch has now become one of the few domestic producers of alumina with an annual output of one million tons. China Nonferrous Network. This article mainly introduces the application of control system of aluminum hydroxide production in our factory, distributed control system, namely DCS (Distributed Control System). China Nonferrous Network. It is a system that uses microprocessor or microcomputer technology to centrally manage and decentralize the production process. It is a new type of process control system. China Nonferrous Network.
In recent years, with the increase in demand at home and abroad, realizing the automation of aluminum hydroxide production to increase production and improve quality has become one of the important means for companies to increase profits. China Nonferrous Network. SUPCON WebField JX-300XP DCS is a domestic distributed control system and has a considerable share in the domestic market. China Nonferrous Network. The system is relatively simple, easy to expand, adaptable, and cost-effective. China Nonferrous Network. It is one of the preferred equipments for automatic control system of alumina and aluminum hydroxide production. China Nonferrous Network.
JX-300XP DCS is composed of control station, operation station, engineer station and communication network. The system structure is shown in Figure 2. China Nonferrous Network. The control station is a unit that directly interacts with field data in the JX-300XP DCS. China Nonferrous Network. From the main control card, data forwarding card, I / O card, electrical unit and other components. China Nonferrous Network. The high-white control system uses only one control station and one operation station. China Nonferrous Network. It is a more economical and practical DCS control system. China Nonferrous Network.
2 Process Our factory's aluminum hydroxide production is mainly divided into three processes, namely semen cooling decomposition, aluminum hydroxide filtration drying and mixing packaging. China Nonferrous Network. The specific process is that the semen is pumped into the seed tank after cooling through the two-stage plate heat exchanger, and is decomposed after being mixed with the AH seed slurry sent from the tertiary settlement, and the degraded slurry is classified through the cyclone and the settling tank. , Settlement, finer AH particles return to the seeding tank, and the coarser particle AH slurry is conveyed to the horizontal belt type vacuum filter through the slurry pump, and passes through four reverse washings and preliminary steam drying to obtain the alkali-adhering, water-adhering, and all qualified The wet material is then dried by a secondary paddle dryer to obtain qualified products with qualified moisture content, chemical composition, alkali, blemishes, uniformity, and whiteness. China Nonferrous Network. The product is purified and sent to the finished product warehouse, and then packaged into the product AH. China Nonferrous Network. According to the needs of the market, some of the materials are ground into fine materials, and then mixed with the coarse materials in a certain proportion to obtain qualified products. China Nonferrous Network.
3 Introduction to the control system According to the characteristics of process production, the semen cooling decomposition and aluminum hydroxide filter drying are categorized as a control system, the mixing and packaging are categorized into a control system, and the two control systems are independent of each other to ensure the orderly production. . China Nonferrous Network. We use the JX300XP control system, each system using an engineer station and an operator station. China Nonferrous Network. The engineer station and operation station communicate with the control cabinet through the SCNET II network. The SCNET II network is a redundant network, which improves the reliability of the system communication. The dual-CPU and dual data forwarding cards are used in the control cabinet. China Nonferrous Network. The system structure is shown as in Fig. 2, this system adopts the dual redundant structure, has guaranteed the stable operation of the system, mixes and controls the systematic structure and Gao Bai's identical. China Nonferrous Network.
3.1 The realization of system control function The high white control system adopts SCNETII network, CPU redundancy, effectively guarantees the stability and security of the system, and the high-white control system realizes the real-time data collection, process control, and alarm of the industrial production process. Trends and other functions have improved the level of automation of aluminum hydroxide production and facilitated the organization of production. China Nonferrous Network.
3.1.1 Logical Control Functions for Electrical Equipment There are two main types of electrical equipment for high-white control systems. One is an industrial frequency motor and the other is a variable-frequency motor. We use different logic control strategies for these two types of motors. Frequency motor We directly take the signal from the control terminal of the low-voltage distribution room equipment. For the variable-frequency motor, we take the signal from the inverter. We do not directly control the motor, but control the motor through the inverter. China Nonferrous Network. Their control logic is slightly different, and one frequency conversion (MR signal) is added to the frequency conversion motor signal. Because the frequency is adjustable, there is also one more control loop. China Nonferrous Network. We take the inverter motor as an example to briefly introduce the realization of the logic control function. The control principle is shown in the figure.
3.1.2 Main regulation control function For process aluminum hydroxide production, process parameters directly affect the quality of the product. Therefore, the acquisition and control of the instrument parameters is very important. For each instrument signal, signal isolation and correction are made to ensure its quality. Accurate and safe, frequency adjustment of variable frequency motor adopts PID single loop control, PID single loop control can either directly perform frequency setting directly or form closed loop, and the system automatically adjusts according to PID parameters. China Nonferrous Network. Liquid balance is also very important in the production of aluminum hydroxide, which is related to the quality of the indicators. Because the flow rate of the material directly affects the liquid volume, we use a PID control loop to control the liquid volume, which is based on the specific production conditions. The operator sets the fluid quantity signal, and the PID regulating circuit adjusts the frequency setting of the variable frequency pump according to the deviation between the measured value and the set value, thereby controlling the size of the flow. China Nonferrous Network. To achieve the purpose of stable production. China Nonferrous Network.
3.1.3 Operation Screen JX300XP is an advanced DCS control system. All instrument and electrical equipment parameters are entered into the control system and displayed and controlled centrally in the control room. China Nonferrous Network. Flowchart screens consistent with the process also provide alarm information and historical trends for operators and managers to operate and view. China Nonferrous Network.
4 Conclusion With the development of information technology, the pace of industrial production automation is irresistible, DCS control system has a wide range of applications in our plant, the system has been put into operation for a year, stable operation, normal, advanced control system application great ease The labor intensity of the operator has brought great economic benefits due to the accuracy of measurement, the accuracy of control, and the greatly improved production efficiency. China Nonferrous Network.
[Keywords]: Aluminum hydroxide production DCS
1 Introduction China Aluminium Zhongzhou Branch is one of the alumina production bases under the China Aluminum Corporation. China Nonferrous Network. The Zhongzhou branch has now become one of the few domestic producers of alumina with an annual output of one million tons. China Nonferrous Network. This article mainly introduces the application of control system of aluminum hydroxide production in our factory, distributed control system, namely DCS (Distributed Control System). China Nonferrous Network. It is a system that uses microprocessor or microcomputer technology to centrally manage and decentralize the production process. It is a new type of process control system. China Nonferrous Network.
In recent years, with the increase in demand at home and abroad, realizing the automation of aluminum hydroxide production to increase production and improve quality has become one of the important means for companies to increase profits. China Nonferrous Network. SUPCON WebField JX-300XP DCS is a domestic distributed control system and has a considerable share in the domestic market. China Nonferrous Network. The system is relatively simple, easy to expand, adaptable, and cost-effective. China Nonferrous Network. It is one of the preferred equipments for automatic control system of alumina and aluminum hydroxide production. China Nonferrous Network.
JX-300XP DCS is composed of control station, operation station, engineer station and communication network. The system structure is shown in Figure 2. China Nonferrous Network. The control station is a unit that directly interacts with field data in the JX-300XP DCS. China Nonferrous Network. From the main control card, data forwarding card, I / O card, electrical unit and other components. China Nonferrous Network. The high-white control system uses only one control station and one operation station. China Nonferrous Network. It is a more economical and practical DCS control system. China Nonferrous Network.
2 Process Our factory's aluminum hydroxide production is mainly divided into three processes, namely semen cooling decomposition, aluminum hydroxide filtration drying and mixing packaging. China Nonferrous Network. The specific process is that the semen is pumped into the seed tank after cooling through the two-stage plate heat exchanger, and is decomposed after being mixed with the AH seed slurry sent from the tertiary settlement, and the degraded slurry is classified through the cyclone and the settling tank. , Settlement, finer AH particles return to the seeding tank, and the coarser particle AH slurry is conveyed to the horizontal belt type vacuum filter through the slurry pump, and passes through four reverse washings and preliminary steam drying to obtain the alkali-adhering, water-adhering, and all qualified The wet material is then dried by a secondary paddle dryer to obtain qualified products with qualified moisture content, chemical composition, alkali, blemishes, uniformity, and whiteness. China Nonferrous Network. The product is purified and sent to the finished product warehouse, and then packaged into the product AH. China Nonferrous Network. According to the needs of the market, some of the materials are ground into fine materials, and then mixed with the coarse materials in a certain proportion to obtain qualified products. China Nonferrous Network.
3 Introduction to the control system According to the characteristics of process production, the semen cooling decomposition and aluminum hydroxide filter drying are categorized as a control system, the mixing and packaging are categorized into a control system, and the two control systems are independent of each other to ensure the orderly production. . China Nonferrous Network. We use the JX300XP control system, each system using an engineer station and an operator station. China Nonferrous Network. The engineer station and operation station communicate with the control cabinet through the SCNET II network. The SCNET II network is a redundant network, which improves the reliability of the system communication. The dual-CPU and dual data forwarding cards are used in the control cabinet. China Nonferrous Network. The system structure is shown as in Fig. 2, this system adopts the dual redundant structure, has guaranteed the stable operation of the system, mixes and controls the systematic structure and Gao Bai's identical. China Nonferrous Network.
3.1 The realization of system control function The high white control system adopts SCNETII network, CPU redundancy, effectively guarantees the stability and security of the system, and the high-white control system realizes the real-time data collection, process control, and alarm of the industrial production process. Trends and other functions have improved the level of automation of aluminum hydroxide production and facilitated the organization of production. China Nonferrous Network.
3.1.1 Logical Control Functions for Electrical Equipment There are two main types of electrical equipment for high-white control systems. One is an industrial frequency motor and the other is a variable-frequency motor. We use different logic control strategies for these two types of motors. Frequency motor We directly take the signal from the control terminal of the low-voltage distribution room equipment. For the variable-frequency motor, we take the signal from the inverter. We do not directly control the motor, but control the motor through the inverter. China Nonferrous Network. Their control logic is slightly different, and one frequency conversion (MR signal) is added to the frequency conversion motor signal. Because the frequency is adjustable, there is also one more control loop. China Nonferrous Network. We take the inverter motor as an example to briefly introduce the realization of the logic control function. The control principle is shown in the figure.
3.1.2 Main regulation control function For process aluminum hydroxide production, process parameters directly affect the quality of the product. Therefore, the acquisition and control of the instrument parameters is very important. For each instrument signal, signal isolation and correction are made to ensure its quality. Accurate and safe, frequency adjustment of variable frequency motor adopts PID single loop control, PID single loop control can either directly perform frequency setting directly or form closed loop, and the system automatically adjusts according to PID parameters. China Nonferrous Network. Liquid balance is also very important in the production of aluminum hydroxide, which is related to the quality of the indicators. Because the flow rate of the material directly affects the liquid volume, we use a PID control loop to control the liquid volume, which is based on the specific production conditions. The operator sets the fluid quantity signal, and the PID regulating circuit adjusts the frequency setting of the variable frequency pump according to the deviation between the measured value and the set value, thereby controlling the size of the flow. China Nonferrous Network. To achieve the purpose of stable production. China Nonferrous Network.
3.1.3 Operation Screen JX300XP is an advanced DCS control system. All instrument and electrical equipment parameters are entered into the control system and displayed and controlled centrally in the control room. China Nonferrous Network. Flowchart screens consistent with the process also provide alarm information and historical trends for operators and managers to operate and view. China Nonferrous Network.
4 Conclusion With the development of information technology, the pace of industrial production automation is irresistible, DCS control system has a wide range of applications in our plant, the system has been put into operation for a year, stable operation, normal, advanced control system application great ease The labor intensity of the operator has brought great economic benefits due to the accuracy of measurement, the accuracy of control, and the greatly improved production efficiency. China Nonferrous Network.