This disclosure relates to a system and device for cleaning impurities, garbage, rocks and etc. from sand. In one embodiment, a sand cleaning device includes a spinning brush head that includes one or more flaps that push sand through a screen while retaining impurities, garbage, and rocks within a receptacle. The system includes a remote power unit for powering the sand cleaning device.

Separation and classification equipment for separating a mixed waste stream into first, second and third fractions. The equipment comprises a feeding member for feeding the waste stream toward a gap and a blower for discharging a stream of air for mixing with the waste stream, as the waste stream falls through the gap. The first fraction falls through the stream of air and collects in a first collection area while the stream of air carries away the second and the third fractions. A rotatable permeable member is arranged to permit the stream of air to pass therethrough and thereby force and retain the third fraction against a surface of the rotatable permeable member and be conveyed, by the rotatable permeable member, toward a third collection area while the second fraction tends to separate, from the rotatable permeable member and the third fraction, and collect in a separate second collection area.

[Object] To provide a building material manufacturing apparatus that is suitable for suppressing clogging of a screen that screens a building raw material. [Solution] A building material manufacturing apparatus X1 includes at least a screen part 10 and a cleaning mechanism part 40. The screen part 10 includes at least one screen sheet 12 that has an inclination and that has a screen mesh. The cleaning mechanism part 40 includes a scraping part 40a. When the apparatus operates in a building material manufacturing mode in which a building raw material M is supplied to the screen sheet 12 and the screen sheet 12 is performing a wave motion, the scraping part 40a is separated from the screen sheet 12, and, when the apparatus operates in a cleaning mode in which the building raw material M is not supplied to the screen sheet 12 and the screen sheet 12 is not performing a wave motion, the scraping part 40a rotates in contact with the screen sheet 12.

A flour sifting device (1), having a flour sifting tank provided with a flour sifting trough with flour sifting holes at the bottom, and a rotating brush located inside the flour sifting tank having a rotating shaft (7*) and devised to brush the flour sifting holes. The rotating brush hasa first plurality of discrete flexible brush elements (12c*) that are distributed on said rotating shaft (7*) and extend therefrom in a radial direction with respect to said rotating shaft (7*) such that collectively they form a screw conveyor with a circular outer contour. The brush elements (12c*) are arranged on a second plurality of separate identical brush modules (12*), each brush module (12*) including a number of said brush elements (12c*), preferably an equal number of said brush elements (12c*), and the brush modules (12*) are individually and removably mounted or mountable on the rotating shaft (7*).