QJB Submersible Mixer Pump — Sewage Treatment & Aeration Agitator The heavy duty QJB submersible mixer pump in cast iron is engineered for the toughest municipal sewage treatment duties. Its three-blade impeller delivers a powerful axial thrust that mixes sludge, keeps solids in suspension and boosts oxygen transfer in aeration tanks — the working conditions most frequently searched for by Russian buyers of погружная мешалка . Key Selling Points Heavy Duty QJB Series: cast