Dry-material weig­hing and dosing hoppers are used for volu­metric feeding of powder mate­rials or small-grained granulates.

Dosed mate­rial is discharged from the weig­hing hopper by the variable-speed metering screw. The hopper can be fed fully auto­ma­ti­cally using a screw conveyor or pneu­matic conveying system.

Capa­ci­tive sensors in the hopper detect the minimum and maximum of the filling level. To avoid bridging of the mate­rial in the hopper, an addi­tional bridge braker is installed in the hopper. In order to adapt the discharge quan­tity to the desired rate of deli­very, the speed of the screw can be changed by using a variable-speed motor.