PNEUMATIC SIZING SCREEN Russian patent published in 2010 - IPC B07B7/83 

FIELD: technological processes.

SUBSTANCE: invention relates to devices for sizing of finely ground polydisperse loose material into two fractions, product particles of which are notable for size and aerodynamic properties. It may be used to separate high-protein fraction of flour from products of wheat grain grinding. Pneumatic sizing screen has fixed helical body, air distribution grid with rotary blades arranged along arc of circumference coaxial to body, and also rotary impeller with radial blades arranged coaxially with air distribution grid and body, nozzle for supply of clean air into space between body and air distribution grid, nozzle for supply of transporting air with initial product into annular space between air distribution grid and impeller, nozzles for discharge of large and fine fractions of products with air. Nozzles of product supply with air and discharge of large fraction with air are equipped with adjustable rotary gates, with the possibility to vary value of clearance between gate and air distribution grid. Rotary blades of air distribution grid have drop-like profile in cross section. Wide part of air distribution grid rotary blade is turned towards spiral wall of body, and sharpened part - towards annular space between air distribution grid and impeller. Nozzle for supply of clean air is equipped with two rotary gates, position of which is adjusted with the help of doubled lever-screw device.

EFFECT: improved efficiency of pneumatic sizing.

3 cl, 2 dwg