Flour sifting device
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 ( 12 c *) 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 ( 12 c *) are arranged on a second plurality of separate identical brush modules ( 12 *), each brush module ( 12 *) including a number of said brush elements ( 12 c *), preferably an equal number of said brush elements ( 12 c *), and the brush modules ( 12 *) are individually and removably mounted or mountable on the rotating shaft ( 7 *).
1 . A flour sifting device ( 1 ), comprising:
a flour sifting tank ( 4 ) provided with a flour sifting trough ( 5 ) with flour sifting holes at a bottom of the flour sifting trough;
a rotating brush ( 8 ) located inside the flour sifting tank ( 4 ) having a rotating shaft ( 7 , 7 *) and arranged to brush the flour sifting holes;
the rotating brush ( 8 ) comprises a first plurality of discrete flexible brush elements ( 12 c, 12 c*) that are distributed on said rotating shaft ( 7 , 7 *) and extend therefrom in a radial direction with respect to said rotating shaft ( 7 , 7 *) such that collectively the first plurality of discrete flexible brush elements ( 12 c , 12 c *) form a screw conveyor with a circular outer contour;
said brush elements ( 12 c , 12 c *) are arranged on a second plurality of separate identical brush modules ( 12 , 12 *), each said brush module ( 12 , 12 *) comprising a number of said brush elements ( 12 c , 12 c *), and the brush modules ( 12 , 12 *) are individually and removably mounted or mountable on the rotating shaft ( 7 , 7 *).
2 . The flour sifting device ( 1 ) of claim 1 , wherein the brush modules have an equal number of said brush elements ( 12 c , 12 c *).
3 . The flour sifting device ( 1 ) of claim 1 , wherein there is at least one of the brush elements ( 12 c ) per each said brush module ( 12 ), said brush element ( 12 c ) forming a complete helical winding.
4 . The flour sifting device ( 1 ) of claim 3 , wherein said brush element ( 12 c ) comprises at least one radial notch and the separate brush modules ( 12 ) are arranged on the rotating shaft ( 7 ) such that respective ones of the notches of the brush modules ( 12 ) are aligned in a direction parallel to the rotating shaft ( 7 ).
5 . The flour sifting device ( 1 ) of claim 4 , further comprising a stirring bar ( 13 ) that extends parallel to the rotating shaft ( 7 ), said stirring bar ( 13 ) being held in the notches of the brush modules ( 12 ).
6 . The flour sifting device ( 1 ) of claim 3 , wherein the brush modules ( 12 ) further comprise a stirring element ( 12 j ) that is arranged on at least one side of the brush element ( 12 c ) and that extends in the radial direction.
7 . The flour sifting device ( 1 ) of claim 6 , wherein the stirring element ( 12 j ) extends over a whole diameter of the brush module ( 12 ).
8 . The flour sifting device ( 1 ) of claim 6 , wherein the stirring element ( 12 j ) is formed integrally with the brush element ( 12 c ).
9 . The flour sifting device ( 1 ) of claim 6 , wherein one of the stirring elements ( 12 j ) is located on each side of the brush element ( 12 c ), and the stirring elements ( 12 j ) on both sides of the brush element ( 12 c ) are located at a common circumferential position.
10 . The flour sifting device ( 1 ) of claim 9 , wherein said stirring elements ( 12 j ) cover a pitch (P) of said brush element ( 12 c ) in an axial direction.
11 . The flour sifting device ( 1 ) of claim 3 , wherein the brush modules ( 12 ) further comprise a stirring element ( 12 j ) that is arranged on at least one side of the brush element ( 12 c ) and that extends in the radial direction, and the brush modules ( 12 , 12 *) are aligned on the rotating shaft ( 7 , 7 *) with respect to a circumferential position of the stirring elements ( 12 j ).
12 . The flour sifting device ( 1 ) of claim 1 , wherein there are a plurality of brush elements ( 12 c *) per each said brush module ( 12 *), and said brush elements ( 12 c *) collectively forming at least one helical winding.
13 . The flour sifting device ( 1 ) of claim 12 , wherein there the plurality of brush elements ( 12 c *) per each said brush module are arranged equally spaced in a circumferential direction.
14 . The flour sifting device ( 1 ) of claim 1 , wherein the brush modules ( 12 , 12 *) are aligned on the rotating shaft ( 7 , 7 *) with respect to a circumferential position of the brush elements ( 12 c , 12 c *).
15 . The flour sifting device ( 1 ) of claim 14 , wherein the brush modules ( 12 , 12 *) comprise a central through-hole ( 12 e , 12 e *) for accommodating the rotating shaft ( 7 , 7 *), said through-hole ( 12 e *) comprising an alignment notch ( 12 m *) and said rotating shaft comprising a longitudinal protrusion ( 7 d *) for engaging said alignment notch ( 12 m *).
16 . The flour sifting device ( 1 ) of claim 1 , wherein said rotating shaft ( 7 , 7 *) has a square section.
17 . The flour sifting device ( 1 ) of claim 1 , wherein the rotating shaft ( 7 ) has one end with a stop ( 7 a ) for the brush modules ( 12 ) and one threaded end ( 7 c ) for threadedly securing said brush modules ( 12 ) on the rotating shaft ( 7 ).