Flow problems in hoppers are often dealt with by hitting the hopper with hammers. This may work in the short term but eventually dents the hopper, increasing the severity of the problem.
Incorrect hopper design is usually a result of the designer not understanding the characteristics of the materials being hoppered or the materials might have changed since the hopper was installed. Due to the range of materials being stored and their unique properties, various flow promotion devices can be used to encourage material discharge. One such device is the New Bin Master Airbrator that is available from Fresco Systems Australasia .
Airbrator air pads combine aeration and vibration and are suitable for material flow applications. Their design creates vibration as the air flows between the pads boot and the hopper wall. This provides an effective flow aid for all types of dry products. Airbrator pads do not require a specific air pressure for operation. Users can use a blower at 35kpa or high pressure air at 415kpa.
Air is introduced into the hopper or silo through Airbrator air pads. As the air discharges in the material, it provides an aeration effect to fluidise the material. The positive air pressure keeps the material from getting under the boot. The air flowing under the boot causes it to vibrate. The vibration of the boot moves material that has the tendency to hang up or bridge.
When the air is removed from the boot, the pressure of the material and the design of the boot forces it against the side wall of the hopper or silo. This prevents material from getting under the boot and back into the air supply. For installation, a 22mm hole in the hopper wall is drilled and Airbrator pads are inserted from the inside and then the rear nut is tightened. An air supply is connected and timing sequence initiated. For larger hoppers or silos, multiple rows or Airbrator pads may be required. The Airbrator pads are manufactured from food grade materials with a stainless steel stem and are rated to 121°C.