Batch is loaded via the feed hopper and is fed by gravity into the feed tube onto the feed screw (manufactured from steel with a special coating to minimise wear) which in turn charges the batch into the furnace.

The screw is actuated by a three-phase asyn-chronous electric motor coupled to a speed reducing gear unit. The motor is controlled by an inverter located in the main control board, driven by a 4-20mA signal from the glass level control, thus ensuring a continuous and smooth regulation of the charging rate. The drive includes large diameter conical roller bearings and a system to prevent batch damaging the bearings, etc.