Low volume magnetic mixing system
A mixing system for use in a process bottle for mixing its contents, the mixing system including a low volume magnetically-driven mixer mounted at the bottom of the bottle. The mixer may have vanes and lower grooves, or no vanes and grooves on both upper and lower faces. The mixer has a “microsized” three-dimensional solid inanimate body to enable insertion through relatively small mouth openings at the top of conventional reactor bottles. Methods of assembly are also disclosed which involve passing the microsized mixer through an open mouth of a process bottle and coupling the mixer with a bearing assembly at the floor of the bottle. The bearing assembly includes fixtures sealed around a hole in the floor of the bottle.
1. An aseptic mixing system, comprising:
an aseptic process bottle having a bottom with a floor, vertical sidewalls and a top wall extending inward from the sidewalls to an upper mouth defining an upper opening with an upper mouth diameter, the process bottle having a center extending from the upper mouth to the bottom;
a shaft having an upper end and a lower end, the shaft disposed in the center of the bottle;
a solid mixer held onto the lower end of the shaft and positioned for rotation about a central axis at the bottom of the process bottle, the mixer being generally circular in plan view and having a generally cylindrical disk-shaped body in which is mounted at least one magnet to enable coupling with a magnetic-drive exterior to the process bottle, the mixer having an overall outer diameter that is less than the upper mouth diameter of the process bottle; and
a bearing assembly mounted inside the process bottle configured to support the mixer for rotation about the central axis.
2. The aseptic mixing system of claim 1 , wherein the mixer has a plurality of circumferentially-spaced vanes upstanding from the disk-shaped body.
3. The aseptic mixing system of claim 2 , wherein the vanes extend radially outward from the disk-shaped body.
4. The aseptic mixing system of claim 2 , wherein there are four of the vanes.
5. The aseptic mixing system of claim 1 , wherein there are a plurality of lower grooves formed in a lower face of the disk-shaped body.
6. The aseptic mixing system of claim 5 , wherein there are four of the lower grooves evenly circumferentially-spaced about the central axis, and four vanes upstanding from the disk-shaped body, and the four lower grooves are offset circumferentially from the four vanes.
7. The aseptic mixing system of claim 1 , wherein the mixer has no vanes upstanding from the disk-shaped body so as to be puck-shaped.
8. The aseptic mixing system of claim 7 , wherein there are plural lower grooves formed in a lower face of the disk-shaped body.
9. The aseptic mixing system of claim 8 , wherein the mixer also has a plurality of upper grooves formed in an upper face of the disk-shaped body, and the upper and lower grooves are radially-extending and evenly circumferentially-spaced about the central axis on each face, and the lower grooves are offset circumferentially from the upper grooves.
10. The aseptic mixing system of claim 8 , wherein there are six of the lower grooves evenly circumferentially-spaced about the central axis.
11. The aseptic mixing system of claim 10 , wherein the six lower grooves are offset circumferentially from six of the upper grooves evenly circumferentially-spaced about the central axis.
12. The aseptic mixing system of claim 7 , wherein the mixer has gradually tapered upper and lower faces so that both faces are frustoconical.
13. The aseptic mixing system of claim 1 , wherein there are a plurality of lower grooves formed in a lower face of the disk-shaped body, and the grooves are linear and extend radially.
14. The aseptic mixing system of claim 13 , wherein the grooves are generally semi-circular in radial cross-section.
15. The aseptic mixing system of claim 1 , wherein the bearing assembly includes a bearing member sealed on the floor of the process bottle around a hole, and which defines a central through hole.
16. The aseptic mixing system of claim 15 , wherein the bearing assembly includes a lower holding nut having an upstanding internally-threaded vertical column sized to pass through the central through hole, the holding nut having a lower flange adhered to an underside of the floor of the process bottle, the bearing assembly further having a screw sized to pass down through a central throughbore in the disk-shaped body and engage the internally-threaded vertical column to secure the mixer above the floor while permitting rotation thereof.
17. The aseptic mixing system of claim 16 , wherein the bearing member has a base flange that defines a downwardly-facing groove, and the bearing assembly includes an O-ring positioned in the groove that seals against the floor of the process bottle around the hole.
18. The aseptic mixing system of claim 15 , wherein the central through hole of the bearing member is internally threaded on both ends, and a lower screw projects upward through the hole in the center of the floor and into the threaded bore to secure the bearing member to the floor, and the bearing assembly includes an O-ring sealed against the floor of the process bottle around the hole by the bearing member.
19. The aseptic mixing system of claim 13 , wherein there are two magnets mounted within the disk-shaped body to enable coupling with a magnetic-drive exterior to the process bottle, and the magnets are positioned within two diametrically-opposed cavities open to an underside of the disk-shaped body.
20. The aseptic mixing system of claim 19 , wherein the two diametrically-opposed cavities are offset from the lower grooves.
21. An aseptic mixing system comprising:
an aseptic process bottle having a bottom with a floor, vertical sidewalls and a top wall extending inward from the sidewalls to an upper mouth defining an upper opening with an upper mouth diameter;
a mixer positioned for rotation about a central axis of the mixer and disposed at the bottom of the process bottle, the mixer being generally circular in plan view and having a generally cylindrical disk-shaped body in which is mounted at least one magnet to enable coupling with a magnetic-drive exterior to the process bottle, the mixer having an overall outer diameter that is less than the upper mouth diameter of the process bottle, the mixer having a plurality of vanes which extend vertically upward into the bottle and radially outward of the disk-shaped body,
the vanes adapted to reduce fluid shear and to gently mix fluid within the bottle; and
a bearing assembly configured to support the mixer for rotation about the central axis,
further comprising a shaft connected to and extending upward from the mixer and above the bottom of the bottle, wherein the shaft suspends the mixer.
22. The aseptic mixing system of claim 21 wherein there are four of the vanes.
23. The aseptic mixing system of claim 21 wherein the bearing assembly includes a bearing member sealed on the floor of the process bottle.
24. The aseptic mixing system of claim 23 wherein the bearing assembly is disposed around a hole in the floor of the process bottle.
25. The aseptic mixing system of claim 21 wherein the bearing assembly is mounted through a hole in a floor of the process vessel configured to support the mixer for rotation about the central axis, and wherein the bearing assembly includes a bearing member adapted to seal on the floor of the process vessel around the hole.
26. The aseptic mixing system of claim 21 wherein there are four of the vanes.