Unloader type A can be used when the silo has an aeration platform or when it is not possible to make a tunnel under the silo itself.
Screw B coveys the product in the central box outside the silo. When the product no longer falls by gravity, screw A equipped with mechanical infeeder is connected from outside.
Screw A is supported and has a variable pitch; it is complete with air lock for flow adjustment.
Unloader type B can be used when there is a tunnel to house a conveyor in order to convey the product outside the silo.