Aerating apparatus

In an apparatus for the aeration of dispersions, which comprises a flotation cell having at least one ring injector associated with it, said ring injector comprising:

• an outer tubular casing defining an axis and having two ends and including a dipersion feed section at one end, a mixing section and a discharge section at the other end and a center core located inside and extending substantially the length of the tubular casing thereby defining said sections as an annular gap,
• support arm means in said feed section for mounting the center core in the casing, the feed section having an inlet and an outlet and the center core forming with the outlet of the feed section an annular gap portion having a first cross section,
• the outer casing being expanded in the form of a step in relation to the outlet of the feed section and the center core having a decrease in thickness at the same point along the axis thereby forming the inlet of the mixing section having a second cross section,
• the center core than having a further decrease in thickness in the form of a groove in the area of the mixing section,
• air ducts extending into the step at the inlet of the mixing section and into the groove of the center core,
• the mixing section having an inlet and an outlet and the cross section at the outlet of the mixing section being greater than the cross section at the inlet of the mixing section,
• the discharge section having an outlet and the cross section at the outlet of the discharge section being greater than the cross section at the outlet of the mixing section.