Feeder unit, feeder module comprising feeder units, and method for discharging a constant mass flow of one or more powders into a receiving container

A feeder module, comprising:

• a plurality of feeder units arranged in a spokes-like configuration in a single level, the plurality of feeder units being two to eight in number, each feeder unit comprising a storage hopper, a weighing cell, a conveyer, and a discharge end;
• and
• a common receiving container connected to the discharge end of each feeder unit, each feeder unit extending radially outwards from an imaginary inner circle defined by the discharge ends of the plurality of feeder units in the common receiving container to an imaginary outer circle defined by radially opposite ends of the plurality of feeder units, the plurality of feeder units being positioned substantially on radii extending from the imaginary inner circle, wherein:
• one or more conveyers of the plurality of feeder units is a twin screw conveyor, at least one of the screws of the twin screw conveyor has:
• a length underneath the storage hopper;
• and
• at least one of:
• a variable pitch along the length underneath the storage hopper;
• and
• a variable diameter along the length underneath the storage hopper.