Patent ID: 7331704
Filing Date: 2008-02-19
Classification: B01F

Abstract:
1. A method for suspending settled solids in a liquid using a mixing assembly having a longitudinal axis, a mixing vessel, a draft tube having vertical slots extending a vertical slot distance at least partially between a first end and a second end of the draft tube, wherein the draft tube is disposed within the mixing vessel and an impeller disposed within said draft tube, comprising: filling the mixing vessel so that a solid suspension level is located at a height on the vertical slot distance of the suspension slots; rotating the impeller in a first rotational direction for a first period of time, wherein said rotating of the impeller in the first rotational direction causes the liquid to flow in a first axial direction along the longitudinal axis; and rotating the impeller in a second rotational direction opposite the first rotational direction for a second period of time, wherein said rotating of the impeller in the second rotational direction causes the liquid to flow in a second axial direction along the longitudinal axis opposite the first axial direction.