HOPPER

A hopper is a large, inverted pyramidal or conical container used in industrial processes to hold particulate matter or flow able material, such as dust, gravel, nuts, or seeds, and dispense them from the bottom when needed. In some specialized applications, even small metal or plastic assembly components can be loaded and dispensed by small hopper systems. For dust collection, hoppers are often installed in groups to allow for greater collection quantity. They are used in many industries to hold material until it is needed, such as flour, sugar, nuts, food pellets, and crushed ores. They are employed in industrial processes that use air pollution control devices such as dust collectors, electrostatic precipitators, and baghouses/fabric filters. Most hoppers are made of steel. Materials can be added manually or automatically to the top of a hopper. For dust collection, it enters the hopper from a collection device, such as baghouses, which are shaken or blown with compressed air to release caked-on dust. Precipitators use a rapping system to release dirt, and the crumbling dust falls into the hopper. Once the material reaches capacity, it is released through an opening in the bottom with a diameter of about 8-12 inches (20-30 cm). Conveyors are sometimes used to carry away particulate matter.