Automatic control of the hottest filling productio

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Automatic control of filling production line

organic acids are important raw materials in chemical, food and other industries. Because of its high unit value, various varieties and specifications, and huge production investment, it has high requirements for the automatic filling production line. There is no such production line in China, and it will cost more than several million dollars to import from abroad. Therefore, domestic development can not only save foreign exchange, but also provide users with timely and convenient services, and greatly improve the automation level of enterprise production, which is of great significance

1. System process description in the organic acid automatic filling production line project undertaken by me, there are three product varieties (1#, 2#, 3#), and there are also three measurement specifications for each variety (a, B, c). Therefore, there will be nine production specifications after the combination. The diversity of varieties and specifications makes the system configuration and function more complex. The organic acid is characterized by strong corrosivity, high product value, unstable density, and unstable flow rate and pressure. Therefore, in the design and manufacturing process. Users not only have high requirements for the corrosion resistance of the materials used in the production line, but also require to prevent dripping during the filling process, and put forward more stringent requirements for accuracy and speed

1) filling material temperature: 5~35 ℃. 2) material density: organic acid about 1.2g/cm3, organic acid salt about 1.3g/cm3. 3) material viscosity: organic acid about 50CP, organic acid salt about 150cp. 4) inlet pressure of feed pipe: 0.2MPa, fluctuation range: 10% 5) layout area of filling equipment: 1200m2. 6) main parameters of the system are as follows, 7) The system process is (take line I as an example): empty barrel sorting - empty barrel entering the filling station - Detection and positioning - filling head falling - filling valve opening - filling start - quality measurement - reaching 90% (no fixed value - compensation value) - small flow of the regulating valve section - reaching 100% (set value - compensation value) - filling valve closing - vacuum adsorption - full barrel out of the filling station - steering - capping - capping - Labeling - stacking - winding - finished product output 8) process of line II (omitted) 2. Control content and functional requirements 2.1 control content 2.2 functional requirements 1) this production line includes: filling line I (suitable for 30kg filling), filling line II (suitable for 250kg or 1200kg filling); 2) Filling line I and filling line II can operate independently or simultaneously. However, No. 2 filling line can only produce one specification (250kg or 1200kg) at a time. The operation combination mode of the whole production line includes I, I + II and II; Line I has three filling stations (1a, 1b, 1c), and each filling station must fill three barrels at the same time (corresponding to three flow meters respectively); There are six filling stations (2a, 2b, 2C, 3a, 3b, 3C) in line II, and only one of them can be selected for work each time (2a and 3a share one flowmeter. 2B and 3b share one flowmeter), while 2a, 2b and 2C (250kg specification) are placed on the pallet in a group of four barrels, which use one flowmeter. The filling process is: after the first barrel is filled, fill the second barrel, the third barrel, and the fourth barrel in turn; Each station of 3a, 3b and 3C (1200kg specification) can only fill one barrel at a time: 3) when the operation mode of the whole production line is I + II, in order to save equipment investment and workshop use area, public stations are adopted in the winding and finished product output parts, so when entering the public stations, programs must be compiled to avoid: 4) convenient data setting and display: one-time filling volume (65~99%), * final set value (100%) Compensation amount (to prevent overshoot, which can be adjusted arbitrarily), qualification determination interval setting, qualified product counting, unqualified product counting, total output (barrels), total filling volume (weight), upper (lower) limit alarm setting and display of instantaneous flow: 5) in order to facilitate debugging and maintenance, on-site manual start/stop switches are equipped beside each conveyor; 6) Emergency stop switches are set on the PLC cabinet door, on site, and on all human-machine interfaces. It is convenient for operators to stop at a fast speed in all areas of the site: 7) the filling station must be selected before the program runs. Valid when auto is selected after. And start running, otherwise it is invalid; 8) At a prominent position in the workshop, set up an alarm light and start the preparatory audible and visual prompt, which starts from the selection of the filling station to the selection of automatic end. The sound and light prompt is intermittent sound, and the alarm sound and light is continuous sound: 9) the flowmeter includes frequency counting output (FC) and analog output (FA), the frequency output is used for cumulative flow filling measurement, and the analog is used for instantaneous flow upper and lower limit alarm: 10) the filling key, status and equipment fault indication are set on the human-machine interface, and there are effective text prompts to avoid faults during the filling process. After the automatic filling is completed, Reset the start filling button. Once the temperature is too high during the filling process, if you need to stop, you can press the manual stop filling button: 11) drip proof design: after the filling is completed, the viscous materials remaining on the surface of the filling head can flow out after a certain time. If they drip outside the container, they will cause pollution. This filling system adopts the vacuum generator back suction system to ensure no dripping and leakage

3. System composition and control scheme 3.1 control system composition, 3.2 control scheme description in order to reduce the field wiring as much as possible, make the system more reasonable, more complete functions, and more convenient to operate, set up a mb+ master station at plc1, and set up several mb+ sub stations at the place where the input and output equipment on the production line is concentrated, as shown in Figure 1

since the filling accuracy of the system is very high, if general flow instruments and analog data acquisition and calculation are used. It will not meet the use requirements. Therefore, in the scheme design, in addition to selecting the mass flowmeter of international famous brand as the measuring instrument, we also used the quantum series products of international * advanced Schneider company as the main controller on the data acquisition and control terminal; To quickly collect the frequency output pulses of 12 mass flow meters. Three high-speed counting modules (5 channels/module, 100kHz) are configured, which have fast acquisition speed and simple and convenient hardware configuration

high accuracy also requires stable flow. On the one hand, the high-level tank is used to adjust the liquid level and pressure. Keep it in a relatively constant area. On the other hand, the instantaneous flow in the pipeline can be easily monitored by using the analog output (4~20ma) of the mass flowmeter. Once it exceeds the upper and lower limits allowed by the system, an audible and visual alarm signal will be sent, and secondary adjustment will be made

for the convenience of users, modify the field data variables. There are three magelis man-machine interfaces on site: OP1 and op2 screens can operate and display the whole production line. OP1 is mainly used to set and display the station selection of 30kg filling line, one-time filling volume (that is, the value of filling to about 90% of * final filling volume, which can be modified arbitrarily), * final filling volume (100%), compensation volume (to prevent overshoot), qualification determination interval setting, qualified product count, unqualified product count Total output (barrels), total filling volume (weight), upper (lower) limit alarm setting and display of instantaneous flow: op2 is mainly used to calibrate and repair the hardness tester or change other hardness test methods when the difference is outside the range of ± 2, set and display the relevant data of 250kg/1200kg filling line, and the rest are the same as OP1, OP3 is used for data setting and display of labeling equipment, and can be used for category, batch number It realizes the maximization of the characteristics of special high molecular materials used in the automobile transmission system and drive, and the modification and display of label data such as production date, expiration date and weight: 1) PC1 in the central control room monitors the whole production line and some key equipment on site in real time; 2) Plc1 is a quantum PLC product, plc2 is a momentum I/O base plate: 3) the configuration of plc1 is (64di, 128do, 12hsc, 12ai), and a 10.4 man-machine interface is through the CPU. The MB port is connected, and the CPU is also connected with momentum substation (substation 2, 32di; substation 3, 32do; substation 4, 32do; substation 5, 32do) and another 10.4 human-machine interface (substation 6) through the mb+ port; 4) Configure a 16 point analog input module on plc1 as the monitoring of instantaneous flow: 5) configure three high-speed counting modules on plc1 as the flow measurement, and each module includes five measurement channels: 6) see table 3:7 for the hardware configuration and address definition of plc1-quantum) see table 4:4 for the hardware configuration and address definition of mb+ stations. Application summary the control system of the filling system integrates computer technology, programmable control technology Data setting and display technology, bus technology, high-speed counting technology, sensor technology and software programming technology. The scheme design is advanced, the software and hardware configuration is reasonable, and the project progress is extremely smooth. All parameters meet or exceed the user acceptance technical standards, especially the measurement accuracy is controlled within 0.1% (the acceptance standard is 0.125%), and the speed reaches 3 barrels/minute. Within 30kg. After two months of trial operation, the whole production line passed the user acceptance on site at one time. Now, the system has been running stably for nearly a year and has been fully affirmed by users (especially foreign technicians)

the successful development of the filling production line fills the domestic gap, and is another successful application of high-end industrial control products in the field of enterprise automation production, which also provides a strong guarantee for the promotion of similar projects

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