AZODOS® type P … DV
The AZODOS® Type P … DV operates in volumetric mode. The powder bulk products flow out of the surge bin into the dosing screw. An agitator is used to ensure uniform discharge. With a frequency-controlled motor, the dosing screw can be switched from coarse to fine flow for precision metering in the downstream weighing process.
AZODOS® type P … DW and DDW
A weigh feeder consists of the basic unit mounted on a platform load cell or integrated in a 3-point weighing frame. It can be mounted in a frame structure on the floor or suspended from the ceiling. The dosing screw meters the bulk material in coarse/fine flow to the downstream process. The amount of product that is metered out of the AZODOS® is weighed. The system operates gravimetrically in accordance with the negative weighing principle.
The AZODOS® type P … DW becomes a loss-in weight feeder (DDW) when it is paired with a corresponding control system (e.g. AZO®CONT). The bulk material is discharged by the dosing screw and the resulting loss in weight per unit of time is registered by the weighing and control system. The actual loss in weight per unit of time (actual throughput) is compared against the required setpoint, which is defined by the downstream process, e.g. extruder. Differences between the actual loss in weight per unit of time and the setpoint are corrected by changes in the screw speed.
The control process is briefly interrupted when the product in the AZODOS® reaches a preset minimum level and the surge bin is replenished. During the refill time the dosing screw output is set to a value based on empirical weight and output data gained from previous metering cycles.