Fluid mixing apparatus and methods for mixing and improving homogeneity of fluids

A method for mixing a liquid-containing non-homogeneous fluid in a container while an opening in the container is sealed, comprising:

• removably inserting a pump assembly within the container to mix the liquid-containing non-homogeneous fluid in the container, the pump assembly including a screw mixing shaft rotatable with respect to the container, the pump assembly having first and second opposing end portions each suitable for passage of the fluid therethrough, the first end portion including at least a first opening for receiving the fluid into the pump assembly and the second end portion including at least a second opening for emitting the fluid from the pump assembly to within the same container, the mixing shaft positioned within the pump assembly to act as a screw conveyor, the pump assembly operable to circulate the fluid within the container while the mixing shaft is rotating, wherein, when at least the first end portion of the pump assembly is inserted into a non-homogeneous portion of the fluid and the mixing shaft undergoes rotation with respect to the container, the portion of the non-homogeneous fluid enters the pump assembly through the first opening, exits the pump assembly through the second opening to effect mixing of fluid circulating through the pump assembly thereby improving homogeneity of the fluid;
• providing a connection interface to connect a motor to the pump assembly and an engagement to rotate the mixing shaft with the motor, the connection interface including a body section having a surface of predefined shape for connection to the pump assembly, the connection interface also providing a sealing engagement between the container and the pump assembly to seal the opening in the container during mixing;
• and
• providing a collar having a first end fixedly positionable for attachment to the second end portion of the pump assembly and a second end to extend away from the pump assembly, the collar second end having an opening along an interior surface with the opening sized and shaped to receive the surface of the body section for an engagement that affixes the body section to the pump assembly.