US 12,447,448 B2
Magnetically-coupled liquid mixer
Michael Juhl Føns, Hinnerup (DK)
Assigned to ALFA LAVAL CORPORATE AB, Lund (SE)
Appl. No. 17/297,008
Filed by ALFA LAVAL CORPORATE AB, Lund (SE)
PCT Filed Nov. 22, 2019, PCT No. PCT/EP2019/082256
§ 371(c)(1), (2) Date May 26, 2021,
PCT Pub. No. WO2020/109167, PCT Pub. Date Jun. 4, 2020.
Claims priority of application No. 18209087 (EP), filed on Nov. 29, 2018.
Prior Publication US 2022/0023810 A1, Jan. 27, 2022
Int. Cl. B01F 33/453 (2022.01); B01F 23/43 (2022.01); B01F 27/91 (2022.01)
CPC B01F 33/4535 (2022.01) [B01F 23/43 (2022.01); B01F 27/91 (2022.01); B01F 33/4533 (2022.01)] 20 Claims
OG exemplary drawing
 
1. Magnetically-coupled liquid mixer having an axial direction and a radial direction and comprising:
a drive mount configured to be secured to a wall of a mixing tank and having a stationary closed-end cylindrical casing arranged in the axial direction and configured for protruding into the tank,
a tank-external drive rotor having a rotatable first magnet array and configured to be inserted in the cylindrical casing,
a member mounted on a centrally located upstanding part of the cylindrical casing in an assembled state of the mixer, the member including a cylindrical part extending in the axial direction and surrounding the centrally located upstanding part of the cylindrical casing and a flange projecting radially outwardly away from a lower end of the cylindrical part;
a bearing that includes a cylindrical part extending in the axial direction and surrounding the cylindrical part of the member, the bearing also including a flange projecting radially outwardly away from a lower end of the cylindrical part of the bearing, the flange of the bearing having a lower surface configured to face towards the cylindrical casing in the assembled state of the mixer, the flange of the bearing extending radially outwardly farther than the flange of the member so that a part of the lower surface of the flange of the bearing positioned radially outwardly of the flange of the member is exposed;
an impeller configured for being rotatably-mounted on the cylindrical casing in the assembled state of the mixer so that the impeller is rotatable about a rotational axis, the impeller including an impeller hub and a plurality of radially extending blades fixed to and projecting radially away from the impeller hub, the impeller being rotatably-mountable on the cylindrical casing, with the member and the bearing interposed between the impeller hub and the cylindrical casing, so that an inner surface of the impeller hub faces towards an outer surface of the cylindrical part of the bearing;
the impeller also including a second magnet array, wherein the first and second magnet arrays in the assembled state of the mixer are configured for enabling rotary torque to be transferred from the drive rotor to the impeller by magnetic coupling between the first and second magnet arrays to rotate the impeller in an intended direction of rotation about the rotational axis of the impeller,
the first and second magnet arrays being arranged to provide a magnetic coupling that ensures levitation of the impeller at all times;
each blade being divided, in the axial direction, by a border line into an upper portion and a lower portion, the lower portion being configured to be located closer to the drive rotor and the upper portion being configured to be further away from the drive rotor in the axial direction, and wherein the upper portion of at least one of the blades is curved or angled in the intended direction of rotation, thereby contributing to moving liquid axially downwards during impeller rotation.