A disposable container, such as a deformable bag, for a fluid, having one or more inlets and one or more outlets and an impeller assembly within the container to cause mixing, dispersing, homogenizing and/or circulation of one or more ingredients contained or added to the container. The impeller assembly has a protective hood surrounding at least a portion of the moveable blades or vanes of the impeller assembly and being above at least a portion of the blades or vanes. The hood surrounds the blades or vanes and arcs over the height of the blades or vanes. The hood is shaped in a dome shape or semi-spherical shape that is around and above the impeller blades and acts as a protector for the container surface against the impeller assembly both during shipping and storage as well as when in use, particularly at lower liquid levels.