All batch lines are equipped with components from leading world-known manufacturers, such as screw feeders, slide gate valves, butterfly valves, pneumatic equipment, vibrators, high frequency pneumatic vibrators, valves, load cells.
The lines are provided with flashlights and alarm signals, systems of emergency shut-off of dosing devices and conveyors. The line are also equipped with speed-control switches, fitted in conveyors and elevators, level indicators fitted in raw materials silos and storage hoppers of the batch, actuators and limit switches, fitted in all gates of raw material silos and storage hoppers of the batch.
There is a possibility to lock drive of discharge valve at raw materials silos and storage hoppers of the batch.
All dosing devices, included in the line, work as completely autonomous modules, which can be controlled by "Master-Controller"/PLC, as well as independently operated. Frequency inverters are installed in order to increase dosage accuracy.
All discharge gates have "medium-flow" position to assure discharge accuracy, at that keeping capacity of the dosing device, and to prevent overflow of the batch conveyors.
Each dosing device is operated by its individual weighing controller. The operator can set dosage, summarize data per each hour, enter setting mode to set all parts of the dosing device, and make calibration.
The weighing controller of the dosing device has the possibility to operate in manual mode. It is linked with "Master-Controller"/PLC by RS-485 serial interface.
The control cabinet of raw materials feeding, dosing and weighing is located in the operator's room. The front side of the control cabinet contains large illuminated circuit diagram with emergency operating function, indicating status of all transporting mechanisms and mixers, dosage devices, and level of raw materials in storage silos. Industrial display and keyboard are located in the front side of the control cabinet.
With the keyboard the operator has the possibility to control the line, to set recipes and working parameters of the line. Large LCD 4-lines 20-symbols display indicates the current status of the line and information about faults. The "Master-Controller"/PLC stores weighing data and transfers information to the computer.
The line is managed by "Master-Controller"/PLC in decentralized/autonomous mode. The operator's workstation is located in the operator room only for visualization of production process, setting of recipes, data storage, and making reports. If any unit should fail, the operation of the complete line will not be stopped.
Such philosophy of system architecture gives a lot of advantages, increasing reliability and maintainability of the line, at the same time significantly reducing length of mounting cables and installation time.
SOFTWARE CONTROL TECHNOLOGY
- Software consists of Input-Output server, supporting data communication with "Master-Controller"/PLC, and generating database of weighing data and emergency situations.
- This software application can be installed in PC of the operator's room, as well as in any PC of plant network. Different access permissions for authorization of plant staff has a possibility to manage on-line, process and analyze working results, monitor the current status of the line, and set recipes directly from the plant laboratory PC.
Operator's workstation can provide:
- User identification with list of accessible operations;
- Clear graphic display of the process in the colors allocated to the respective status onto the PC monitor;
- Operations: Start, Temporary and Emergency Shutdown of the line, and Restore after interruption of working process;
- Browsing and modification of the recipe. Recipe determines by parameters of dosage, parameters of preliminary discharge and parameters of delay in discharge of raw materials. These parameters make possible "sandwich" layering of raw materials onto conveyor belt and charging of raw materials in the mixer under the ordered sequence;
- Making of reports for raw materials consumption within any time interval, indicating weighing accuracy;
- Statistical evaluation of batch data written to the archives.