1500mm Hot Strip Conveyor Chain
In order to increase the storage of finished products and improve the transportation capacity of steel coils, a new finished product warehouse and transportation chain system were built. Firstly, it introduces the process layout, equipment composition, configuration of transmission system and automation system, then describes the automatic control function and monitoring function, and finally explains the operation of the whole system.
Key words: transportation chain; automatic control function; monitoring function
The 1 500 mm hot-rolled strip steel project was completed and put into operation in June 2005 , and the production was normal after it was put into operation . Due to the expansion of production capacity after completion , there is a problem of insufficient storage capacity for finished products . In order to relieve the pressure on finished product storage , it was decided to expand the finished product warehouse . In the east of the existing main factory building, two spans of the finished product warehouse will be expanded , the spans are 39 m and 40 m respectively , and the length is 192 m . In order to realize the fast transportation of steel coils to the newly built finished product warehouse , a transportation line was built in the newly built factory building .
- Process layout and equipment composition The transportation system adopts the horizontal coil transportation method , and the entire transportation chain system consists of 1 # rotary platform , coil transport trolley , online sampling device , 1 # transitional stepping conveyor , weighing device , and full Automatic numbering machine , 1 # steel coil conveyor chain , 2 # transitional stepping conveyor , 2 # steel coil conveyor chain , 5 # stepping conveyor , 6 # stepping conveyor and 3 hydraulic rewinding machines . After the steel coil is rolled off the assembly line, the steel coil is transported from the 1 # rotary table to the sampling device by the coil transport trolley , and semi-automatic circumferential bundling is carried out after sampling ; the steel coil enters the 1 # transitional stepping device after bundling , and the There are online weighing device and automatic marking machine . 2 # transitional stepping device is arranged between 1 # and 2 # transport chains . On the 1 # steel coil transportation chain, the steel coil can be rolled off the line by the 5 # stepping conveyor and enter the newly built 40m span . The steel coil on the 2 # steel coil transport chain is transferred to the newly built 39 m span through the 6 # stepping conveyor . Three newly-built rewinding machines are arranged between the two new spans , and are used to turn the horizontal rolls into vertical rolls for delivery . The control system starts from 1 # steel coil turntable , all the way to 6 # The stepper transporter ends . There are 13 pairs of cold metal detectors installed on the entire transportation line , which are used to detect the position of steel coils on the transportation line , and provide logic sequence control signals when the automatic method is adopted .
- transmission system
1 # , 2 # The transport chains are all driven by AC variable frequency induction asynchronous motors . The AC motor adopts a domestic variable frequency special motor with wide speed regulation range , large overload capacity , high mechanical strength , stable and reliable operation , rated voltage AC 380 V , rated frequency 50 Hz , and continuous speed regulation within the range of 3 Hz to 100 Hz ; power supply The device adopts SIEMENS company's 6SE70 series vector control three-phase AC drive system voltage type frequency conversion speed regulating device . An incremental encoder is installed at the end of each conveyor chain variable frequency motor for step control of the conveyor chain . The cooling fan of the transportation chain , the working pump of the hydraulic station and the power supply of the heater are powered by low-voltage withdrawable MCC cabinets , and the working pump motor of the hydraulic station is powered by a Syrp soft starter . Proximity switches are installed at the limit positions of each hydraulic actuator for logic sequence control .
In this scheme, two power transformers are set up ( one for one ) For the power supply of the above equipment , the power supply of the transmission chain drive motor is no longer provided with a separate rectifier transformer , and a line reactor is connected in series on the incoming line side of the frequency converter of each drive motor to isolate it from other equipment in the same grid . The power supply on the power supply side of the transformer comes from the medium broadband 10 kV high distribution room . Figure 1 is a single-line diagram of the power supply of the transmission line transmission system .
- automated system
3.1 Automation system configuration
The automation system mainly consists of an operator station ( HMI) , a set of PLC and several remote I / O slave stations , programmers , printers , industrial Ethernet ( TCP / IP protocol ) , industrial field bus ( Profibus - DP) and other components . operator station ( HMI) selects Advantech industrial computer , and is equipped with WinCC monitoring software from Siemens , and is set to operate in the transportation line 8CS
Indoor ; PLC chooses Siemens S7-400 ( CPU416- _
2DP ) series of products , the entire PLC control cabinet is arranged in the automation control room . Set up remote station ET 200m on the transportation line and each operation platform of the hydraulic station , It is mainly used for stand-alone equipment debugging and shutdown maintenance test run . Industrial Ethernet is used for data exchange between PLC and operator station , PLC and rolling line automation system ; industrial field bus ( Profibus - DP ) For data exchange . Automatic spraying machine , automatic baler , electronic scale equipment through industrial Ethernet ( TCP / IP protocol ) It is directly hung on the automation system of the main rolling line to complete high-speed data communication and information exchange . The block diagram of the automation system is shown in Figure 2 .
The steel coil transportation control system is divided into two levels : basic automation level and monitoring level . The monitoring computer uses an Ethernet switch to form a switched network , and communicates with the network system of the basic automation level and other processes . The entire basic automation system uses one S7-400 plc as the host computer ,
It forms a distributed I / O control system with ET 200m , which is used for sequence control , position control , speed control and hydraulic station control of the entire line of transportation equipment . In the operation room where the signal is relatively concentrated and on-site, remote ET200M I / O is used for on-site construction and pipe wiring . One field control box is installed for each walking beam , and one set of ET200M is used to install it on the side of the corresponding walking beam. , the field equipment control boxes are connected through the Profibus bus , and the PLC master station and the remote I / O station use the Profibus network for data exchange . The realization of related equipment control functions is completed in S7-400 PLC , and the realized control functions include : manual and automatic control of hydraulic station working pump , circulation pump , heater and cooling water ; hydraulic station system pressure , system oil temperature , fuel tank fluid The automatic control of position ; the action and logic interlock control of hydraulic station ; the alarm control of hydraulic station ; the speed , position , action and logic interlock control of each transportation chain ; the speed and position control of each stepping conveyor ; the speed setting of the whole line , Matching coordination , technological process and alarm control , logical interlocking control of equipment . The control process of the transmission system is as follows : The PLC communicates with the frequency converter through the Profibus bus , and the PLC transmits speed , start-stop , block and other commands to the transmission device , and the transmission device transmits status signals such as speed actual value , current value , and alarm For PLC , the working status of the transportation chain is automatically controlled through PLC and frequency converter .
3. 3 HMI monitoring system
The computer monitoring system consists of an operator station and an engineer station , and exchanges data with PLC through a switch .
One operator station is set up in the operation room for the steel coil transportation system
stand . Due to the long steel coil transportation line , in order to reduce on-site wiring and ( HMTI ) , HMI mainly monitors and monitors the parameters of the entire unit on the screen
The main functions of the production data setting are as follows : ①Graphic system : used to freely configure the screen , and operate completely through graphic objects , which have dynamic attributes and can be configured online ; ②Alarm information system : record and store events and display them , information classification and reports can be freely selected ; ③ variable archive : receive , record and compress measured values , display and further edit curves and charts ; ④ report system : users can freely choose a certain report format , Process the current data of the operation document and the user report output according to time sequence or event trigger ; ⑤Processing functions : monitoring and fault alarm of each equipment in the hydraulic station , monitoring of the transmission system of each transport chain , monitoring of the operating status of each stepping conveyor , steel coil Display of the production process of the transportation system , input of finished product specifications , including coil weight , width , plate thickness, etc. , unit alarm signal display , remote operation control of hydraulic and lubrication stations , etc.
- console
There is one main operating platform and 6 auxiliary operating platforms ( point ) , each operating console next to the unit is an operation slave station , the main operating console and auxiliary operating console communicate with the main PLC through remote I / 0 (ET200M) , which saves costs and facilitates maintenance ; the main operating console is placed in the main operating room . In addition to the operation of regional equipment , the selection of the working mode of the whole line must also be completed . 5 Conclusion
Since the steel coil transportation chain system was put into operation in January 2008 , it has accelerated the transportation efficiency of finished steel coils and laid the foundation for fast-paced production . At the same time, the operation frequency of driving and the labor intensity of operators are greatly reduced , which contributes to energy saving and consumption reduction and reduction of post quota .
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