Elkem Solar - Raw Material System

Pyro plant special purpose dispensary system
Bucket elevators
The bucket elevators bring the material up from level 6.1 to level 17.2. These have a fixed speed and therefore had a limited capacity
Vibro Feeders for silicon (SI) feed line (VF-S1 to S7)
Controlled by PLC based on filling level in weighing hoppers at level 17.2
The material from docking station quality SI-A is fed to hopper SI-A, docking station quality SI-B to hopper SI-B and docking station SI-C to hopper SI-C.
Weighing Hoppers (SI-A, SI-B and SI-C)
Weighing hoppers at level 17.2 are on load cells which provide a signal to the weighing electronics Siemens Module.
The last vibro feeder with start / stop of feed to the Otto Junker Charger
The desired batch amount as well as Start and Stop of filling of material coming from the bucket elevators based on load cell signal (Siemens Module)
The weighing hoppers are filled via the bucket elevator, diverter valve and 2 bi-directional vibro feeder – VF-S4. They are emptied by means of individual vibration feeders under each weighing hopper to the last vibro feeder. Further transport of materials into the furnace is done by means of the Otto Junker Charger.
Function Method
The Alloy Feeding System is a standalone unit. Batch sizes are sent from the control room to the systems PLC.
The PLC receives a set point for a batch and start-up signal from the control room. The PLC will then start the vibro feeders between the weighing hoppers and the Otto Junker furnace charger arm and weigh out the "ordered" amount of material.
When the vibrator feeders under the weighing hoppers stop, the subsequent vibratory feeders will run a certain number of seconds afterwards to ensure emptying the whole system. Before the weighing hoppers start to feed out the required batch size, the PLC checks to make sure there is enough material to feed out of the weighing hoppers (this is defined as the maximum intended batch size for its particular quality + 10%).