Method, an Apparatus and a Rotor for Homogenizing a Medium
The present invention relates to a method, an apparatus and a rotor for homogenizing a medium. The invention may be utilized in all areas of industry where mere homogenisation of a medium or mixing of at least two flowing media is needed. A preferred application of the invention can be found in pulp and paper making industry where various chemicals have to be mixed with fiber suspensions. A characterizing feature of the invention is the symmetry of the homogenising operation in the homogenising chamber.
1 . A method of homogenizing a medium in an apparatus, the apparatus including a housing having a homogenising chamber with a circumferential wall, and two end caps ( 40 , 42 ; 140 , 142 ) at the opposite ends of the chamber, the circumferential wall having an inlet opening ( 340 , 1340 ) and an outlet opening ( 360 , 1360 ), the inlet opening ( 340 , 1340 ) communicating with an inlet duct ( 34 , 134 ), and the outlet opening ( 360 , 1360 ) communicating with an outlet duct ( 36 , 136 ), both openings ( 340 , 1340 ; 360 , 1360 ) having a centre; and a rotor ( 38 , 138 ) having blades ( 48 , 148 ) and an axis AR extending through the homogenising chamber; in which method the medium to be homogenised is introduced into the homogenising chamber transverse to the rotor axis AR through the inlet duct ( 34 , 134 ) and the inlet opening ( 340 , 1340 ), is homogenized in the chamber and is discharged therefrom via the outlet opening ( 360 , 1360 ) and the outlet duct ( 36 , 136 ),
characterized in
providing the homogenising chamber with a centreline plane CL P between the end caps ( 40 , 42 ; 140 , 142 ), the centreline plane CL P running essentially via the centres of the inlet opening ( 340 , 1340 ) and the outlet opening ( 360 , 1360 ) at essentially right angles to the rotor axis A R , and
forcing the medium within the homogenising chamber, in addition to radially circulating movement, to axially circulating symmetrical movement on both axial sides of the centreline plane CL P by the rotor blades ( 48 , 148 ) being arranged symmetrically on both sides of the centerline plane CL P and being inclined in relation to a plane defined by the rotor axis A R and an intersecting point between the relative rotor blade and the centerline plane CL P .
2 . The method as recited in claim 1 , characterized in introducing the medium along the centreline plane CL P into the homogenising chamber.
3 . The method as recited in claim 1 , characterized in discharging the medium along the centreline plane CL P from the homogenising chamber.
4 . The method as recited in claim 1 , characterized in pumping the medium by means of the blades ( 48 , 148 ) towards the ends caps ( 40 , 42 ; 140 , 142 ) of the housing.
5 . An apparatus for homogenizing a medium, the apparatus including a housing having a homogenising chamber with a circumferential wall, and two end caps ( 40 , 42 ; 140 , 142 ) at the opposite ends of the chamber, the circumferential wall having an inlet opening ( 340 , 1340 ) and an outlet opening ( 360 , 1360 ), the inlet opening ( 340 , 1340 ) communicating with an inlet duct ( 34 , 134 ), and the outlet opening ( 360 , 1360 ) communicating with an outlet duct ( 36 , 136 ), both openings ( 340 , 1340 ; 360 , 1360 ) having a centre; and a rotor ( 38 , 138 ) with an axis A R extending through the homogenising chamber, said rotor having blades ( 48 , 148 ), characterized in the homogenising chamber having a centreline plane CL P between the end caps ( 40 , 42 ; 140 , 142 ), and running essentially via the centres of the inlet opening ( 340 , 1340 ) and the outlet opening ( 360 , 1360 ) at essentially right angles to the rotor axis A R ; the homogenising chamber being essentially symmetrical in relation to the centreline plane CL P , said rotor blades ( 48 , 148 ) being arranged symmetrically on both sides of the centerline plane CL P and being inclined in relation to a plane defined by the rotor axis A R and an intersecting point between the relative rotor blade and the centerline plane CL P for forcing the medium within the homogenizing chamber to axially circulating symmetrical movement on both sides of the centerline plane CL P .
6 . An apparatus as recited in claim 5 , characterized in that the homogenising chamber is provided with means for closing the axial centre thereof and/or in that the homogenizing chamber around the axis A R of the rotor ( 38 , 138 ), i.e. the centre of the rotor, is closed.
7 . An apparatus as recited in claim 6 , characterized in that said closing means comprise the rotor shaft ( 44 , 144 ) extends through a first end cap ( 40 , 140 ) into the homogenising chamber.
8 . An apparatus as recited in claim 7 , characterized in that the rotor shaft ( 44 , 144 ) extends through a first end cap ( 40 , 140 ) to the proximity of the opposite, second end cap ( 42 , 142 ).
9 . An apparatus as recited in claim 7 , characterized in that said closing means comprise the rotor shaft ( 44 , 144 ) having an end surface, and a member protruding axially from the second end cap ( 42 , 142 ) towards the rotor shaft ( 44 , 144 ) to the proximity of the end surface of the rotor shaft ( 44 , 144 ).
10 . An apparatus as recited in claim 8 , characterized in that the rotor shaft ( 44 , 144 ) has an end surface, and the distance from the end surface to the second end cap ( 42 , 142 ) or the member thereon is of the order of 1 to 5 millimetres.
11 . An apparatus as recited in claim 6 , characterized in that said closing means comprise the rotor shaft ( 44 , 144 ) extending through the homogenising chamber and through the second end cap ( 42 , 142 ).
12 . An apparatus as recited in claim 5 , characterized in that the rotor ( 38 , 138 ) is provided with unitary blades ( 48 , 148 ) extending from the proximity of the first end cap ( 40 , 140 ) to the proximity of the second end cap ( 42 , 142 ), and being arranged symmetrically in relation to the centreline plane CL P .
13 . An apparatus as recited in claim 12 , characterized in that the des ( 48 , 148 ) are bent at the centreline plane CL P such that they are inclined on both sides of centreline plane CL P in the same direction in relation to the centreline plane CL P .
14 . An apparatus as recited in claim 5 , characterized in that the rotor ( 38 , 138 ) is provided with separate blades arranged metrically in relation to the centreline plane CL P .
15 . An apparatus as recited in claim 14 , characterized in that the des are inclined on both sides of the centreline plane CL P in the same direction in relation to centreline plane CL P .
16 . An apparatus as recited in claim 13 , characterized in that the angle of inclination is 20 to 60 degrees, the part of the blade ( 48 , 148 ) closest to the centreline plane being the leading part of the blade ( 48 , 148 ).
17 . An apparatus as recited in claim 5 , characterized in that the blades ( 48 , 148 ) are fastened to the shaft ( 44 , 144 ) by means of arms ( 50 , 150 ) leaving a gap between the blades ( 48 , 148 ) and the shaft ( 44 , 144 ).
18 . An apparatus as recited in claim 5 , characterized in that the blades ( 48 , 148 ) are fastened to the shaft ( 44 , 144 ) such that the blades ( 48 , 148 ) are positioned at a distance from the wall of the housing ( 32 , 132 ).
19 . An apparatus as recited in claim 5 , characterized in that the cross-sectional shape of the homogenizing chamber is one of cylindrical, elliptic and polygonal.
20 . An apparatus as recited in claim 5 , characterized in that the rotor ( 38 , 138 ) is positioned within said homogenising chamber centrally.
21 . An apparatus as recited in claim 5 , characterized in that the rotor ( 38 , 138 ) is positioned within said homogenising chamber eccentrically.
22 . An apparatus as recited in claim 5 , characterized in that the homogenizing chamber is provided with stationary turbulence elements in the form of pins, blades, ribs or bars.
23 . An apparatus as recited in claim 6 , characterized in that said closing means converge towards the rotor axis A R from the centerline plane CL P outwards.
24 . A rotor for homogenizing a medium in a homogenizing chamber, the rotor having an axis A R , a shaft ( 44 , 144 ), and blades ( 48 , 148 ) attached on the shaft ( 44 , 144 ) at a distance from the shaft ( 44 , 144 ), characterized in that the rotor ( 44 , 144 ) has a centreline plane CL P perpendicular to the rotor axis A R , and that the blades ( 48 , 148 ) are arranged symmetrically on both sides of the centreline plane CL P and are inclined in relation to a plane defined by the rotor axis A R and an intersecting point between the relative rotor blade and the centerline plane CL P for forcing the medium within the homogenizing chamber to axially circulating symmetrical movement on both sides of the centerline plane CL P .
25 . A rotor as recited in claim 24 , characterized in that the rotor ( 38 , 138 ) has an axial center and means for closing said axial centre of the rotor and/or in that the axial centre of the rotor ( 38 , 138 ) is closed.
26 . A rotor as recited in claim 25 , characterized in that said closing means converge towards the rotor axis A R from the centerline plane CL P outwards.
27 . The rotor as recited in claim 24 , characterized in that the rotor ( 38 , 138 ) is provided with unitary blades ( 48 , 148 ) extending from the proximity of the first end cap ( 40 , 140 ) to the proximity of the second end cap ( 42 , 142 ).
28 . A rotor as recited in claim 24 , characterized in that the rotor ( 38 , 138 ) is provided with separate blades arranged symmetrically in relation to the centreline plane CL P .
29 . A rotor as recited in claim 24 characterized in that the blades ( 48 , 148 ) are inclined in relation to the centreline plane CL P .
30 . A rotor as recited in claim 24 , characterized in that the blades ( 48 , 148 ) are bent at the centreline plane CL P .
31 . A rotor as recited in claim 24 , characterized in that the blades ( 48 , 148 ) are bent at the centreline plane CL P such that they are inclined on both sides of the centreline plane CL P in the same direction in relation to the centreline plane CL P .
32 . A rotor as recited in claim 29 , characterized in that the angle of inclination is 20 to 60 degrees, the part of the blade ( 48 , 148 ) closest to the centreline plane being the leading part of the blade ( 48 , 148 ).
33 . A rotor as recited in claim 24 , characterized in that the blades ( 48 , 148 ) are fastened to the shaft ( 44 , 144 ) by means of arms ( 50 , 150 ) leaving a gap between the blades ( 48 , 148 ) and the shaft ( 44 , 144 ).