Application of Emerson EC10 series PLC in twin scr

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Application of Emerson EC10 series PLC in twin-screw plastic extrusion granulator chengzhinong of Nanjing Ruihang Technology Co., Ltd. Abstract: Emerson PLC communicates with the heating instrument through the communication port to realize the temperature control of the material and extrusion system in the forming process. Other logic controls and analog quantities realize the automatic control of the whole system and provide a friendly man-machine interface

1. Host

an extruder host is composed of extrusion, transmission, heating and cooling systems

· the extrusion system is mainly composed of screw and barrel. It is a key part of the research and development that the epoxy resin measuring equipment of cannon is matched with an existing press in the company's laboratory

· the driving screw plays a role in the transmission system. It is necessary to ensure that the screw has the required torque and speed during the working process

· the heating and cooling system is mainly used to ensure the temperature control of the material and extrusion system in the forming process

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2 Auxiliary machine

the composition of the auxiliary machine of the extrusion equipment depends on the type of products. Generally speaking, the auxiliary machine is composed of agent penetration setting device, cooling device, traction device, cutting device and product coiling or stacking device

3. Control system

the control system of the extruder is mainly composed of electrical, instrument and actuator. Its main functions are:

(1) control the driving motors of the main and auxiliary machines, meet the speed and power required by the process requirements, and ensure the coordinated operation of the main and auxiliary machines

(2) control the temperature, pressure, flow and product quality of main and auxiliary machines

(3) realize the automatic control of the whole unit

II. Control points of plastic extruder

1. The multi-stage barrel has precise temperature control in multiple temperature zones, and can carry out two-way heating/cooling control. In the Spring Festival of 2020, affected by the sudden epidemic situation in Wuhan and the superposition of Spring Festival and other factors, some commodities in some regions, especially the protective and medical supplies related to pneumonia caused by novel coronavirus infection, such as drugs, medical devices, medical masks, disinfection and sterilization, etc., have a fair use control accuracy of ± 1 ℃, The temperature can be displayed and modified

2. The feeder and the main machine can be controlled by speed regulation and display parameters such as current and speed

3. The solution pressure can be displayed and over limit alarm can be given

4. Real time monitoring of system status and real-time modification of various recipe parameters

5. The system shall be provided with perfect protection to automatically protect the equipment in case of abnormal conditions such as overcurrent

6. Realize interlocking and logic control according to process requirements

III. system configuration scheme

1. Emerson ecbra1 is used as the main PLC, integrating two 12bit analog inputs and one 12bit analog output. In addition, the ECAD analog input module and ECDA analog output module are expanded. The system can provide 16 channel switching value input, 14 channel switching value output, 6 channel analog value input and 5 channel analog value output

2. Temperature control: temperature control is independently completed by the temperature control module, with built-in heating/cooling double PID operation, and supports RS485 serial communication function. It is connected with the COM1 communication port of PLC, and adopts free communication protocol for data exchange. It can read the actual temperature and heating/cooling status of each area and display them on the touch screen, and modify the temperature setting value and PID parameters on the touch screen

3. Speed regulation control: Emerson ev2000/ev1000 series frequency converters are used for speed regulation control of the host and feeder. The unique magnetic flux vector control technology ensures 180% starting torque of the motor at 0.5Hz and the speed accuracy is within 0.5%. The speed can be arbitrarily modified on the touch screen, and the V analog signal can be converted to the frequency converter through the analog output module, so as to achieve the accurate speed setting of the host and the feeder. At the same time, the frequency converter feeds back the current, speed and other parameters to the main PLC through the analog input module, and displays them on the touch screen and carries out over limit alarm protection control. This native of Guangzhou believes that life needs to find its own world before it becomes meaningful

4. Dissolved pressure display: the pressure sensor outputs mA analog signal, which is directly connected to the PLC Analog input interface. After being converted into digital quantity, the pressure value can be displayed, and the alarm value can be set on the touch screen for overpressure alarm

5. Man machine interface: 10.4 inch true color touch screen is selected to connect with the COM0 communication port of PLC, and MODBUS serial communication protocol is used for data exchange. It can display the system operation status in real time, control the system equipment, display the system operation data, alarm content, modify the process formula, etc

6. Interlock and logic control: the capacity of EC10 series PLC program can reach 12K steps, and the instruction processing speed is 0.3us. It can write programs according to the system process requirements to achieve perfect logic control

IV. control system features

1. Two built-in serial communication ports can communicate with the touch screen and other external devices at the same time

2. The main PLC has built-in analog input and output, with high cost performance

3. The system can be expanded to 128 channel switching value and 19 channel analog value with good expansibility

4. Large data capacity, which can store multiple groups of formula parameters and other production parameters

v. application summary

a polymer equipment company in Nanjing is specialized in the R & D, production and sales of twin-screw plastic extrusion granulation equipment. Its control system widely adopts Emerson EC10 series PLC, which has high cost performance, stability and reliability, and is highly praised by customers. (end)

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