Storage silos are cylindrical shape structures with the slip and straight form. Concrete silos are the larger in terms of diameter and height . Silos could be made of many materials. Wood , concrete , cast concrete, and steel Plates , glass lined steel bolted type etc. These vary according to cost durability. Silos storing grain, cement and chemical Powders are typically unloaded with air slides . Silos can be unloaded into rail cars, trucks or conveyors.

A silo unloader specifically refers to a special cylindrical rotating pickup device used inside a single tower silo . The main operating component of the silo unloader is suspended in the silo from a steel cable on a pulley that is mounted in the top-center of the roof of the silo. The vertical positioning of the unloader is controlled by an electric winch on the exterior of the silo.

The silo unloader mechanism consists of a pair of counter-rotating toothed augers which rip up the surface of the silage and pull it towards the center of the unloader. The toothed augers rotate in a circle around the center hub, evenly chewing the silage off the surface of the pile. In the center, a large blower assembly picks up the silage and blows it out the silo door, where the silage falls by gravity down the unloader tube to the bottom of the silo, typically into an automated conveyor system.