Separated addition and weighing of modifier, stabiliser, chalk and TiO2
High cycle rate with high dosing accuracy
Conveying and storage of the dryblends
Feeding of extrusion lines
Integration of the heater-cooler mixer in the control and process control system
The Solution
Pneumatic conveying of components with separate weighing at low height
The PVC is added from the external silos via suction weighing onto the main scale above the heater-cooler mixer. The PVC is selected from the various external silos via a multiport valve, which is arranged directly in front of the suction conveyor scale. This enables very high similarity in the loading of the main scale.
All other auxiliary materials, which are present in big bags or sacks, are placed on the level of the heater-cooler mixer and conveyed separately in the feed tank above the mixer. Dosing screws under the feeding vessel fill the remaining scale hoppers in the area of the mixer.
Titanium dioxide and chalk are also conveyed from external silos into separate feeding vessels and are then metered into the scale hoppers via vibrating screws.
After the heating-cooling mixing process, the dryblend is emptied into a mixing tank. In order to achieve higher homogeneity of the various dryblends, they are conveyed into two AZO homogenising silos and mixed again there. The extruder lines are fed from the homogenising silos via a pneumatic conveying system designed as a suction conveyor.
The complete system, including the heater-cooler mixer, is controlled, monitored and completely documented by the AZO process control and visualisation system as well as the PLC.
The entire system can be viewed via remote maintenance.
