Continuously operating air-jet sieve

摘要

A description is given of a continuously operating air-jet sieve with a planar, rectangular sieve surface and at least one slot nozzle which is arranged underneath the sieve surface and can be moved parallel thereto. In the case of a device of this type, which serves to pneumatically sieve fine-grained materials, air from below is blown through the slot nozzle against the sieve surface whilst the slot nozzle is moved at a small distance from the sieve along the entire sieve surface. Air penetrates through the sieve surface initially in a sharp jet in order to blow through the sieve meshes and to loosen up the material to be sieved and then in a gentle flow in the reverse direction, the fine material being conveyed through the sieve meshes. An air-jet sieve of constructionally simple design which makes full use of the sieve surfaces and makes it possible easily to adjust the retention time of the material being sieved on the sieve - and the resultant high, specific sieving performance - is obtained when the sieve surface is constructed as the floor of a closed vibrating conveyor with a vibrator drive, the mouth of the slot nozzle is of approximately the same length as that of the sieve surface and is directed parallel to its longitudinal side, and the slot nozzle is moved vertically with respect to the conveying direction of the vibrating conveyor.