Surface Aerators for Wastewater Treatment - Vertex

Best Mechanical Aerator

Corgin’s Vertex Surface Aerator is, to our knowledge, the most efficient world-proven mechanical aerator. The modern impeller design is over 50% more efficient than some older designs. The distinctive seven-bladed impeller with its controlled splash pattern is unique. In addition, it has 7 main features which set it apart from the rest:

Excellent Oxygenation and Mixing

The Vertex Surface Aerator has the best mixing capability of any vertical shaft surface aerator. Due to the unique blade design, the impeller induces a strong axial flow pattern which ‘pumps’ oxygen-deficient water up from the tank floor and forces it out to the tank sides. This strong, deep circulation improves oxygen transfer and mixing throughout the tank. This action is superior to the surface radial flow pattern created by most other similar vertical shaft surface aerators, which provides little dissolved oxygen and mixing at depth. This advantage gives Vertex aerators efficiency gains of up to 25% in clean water tests compared to other modern designs.

Consistent High Efficiency

The efficiency of Vertex is maintained for the full lifetime of the aerator, often up to 30 years. This makes their whole life cost efficiency compare favourably with other aeration technologies such as Fine Bubble Diffused Air, which always show a decline in efficiency over time and require new diffuser membranes to regain their efficiency.

We guarantee a Standard Aeration Efficiency (SAE) of 2.3kgO2/kWh on most of our proposals; however, independent tests have shown results of up to 2.8kgO2/kWh.

Extremely Low Reaction Forces

The design of Vertex is such that both radial and axial forces are much lower than with conventional surface aerators. This has many advantages – primarily that the forces and vibration on the gearbox bearings and mounting structure are significantly lower.


The design and the shape of the blades is such that it is virtually impossible for rag or other detritus to attach to the impeller.

Low Maintenance Costs

All maintenance items are accessible from the mounting platform, and maintenance is limited to an annual oil check (2 years with synthetic oil) and periodic checking of greasing points.

Wide Turndown Range

Depending on circumstances, it is possible for a single Vertex aerator to transfer anything from 1 to 500 kg O₂/h into water. Their Standard Aeration Efficiency (SAE) is near-constant over a wide range of speeds and immersion depths.

Universal Applications

Vertex can be installed in a fixed or floating configuration in most tank types: aeration tanks, oxidation ditches, SBRs, lagoons, balance tanks and sludge tanks. They maintain high aeration efficiency in a wide range of wastewater, effluent and clean water applications, and aeration performance does not deteriorate with age as with many fine bubble diffused air systems. In activated sludge applications, the unique conical impeller ensures complete mixing of mixed liquor suspended solids down to 5½ m water depth (8 m with draft tube).

Our Vertex Surface Aerator is a modern alternative to, and suitable replacement for, existing vertical shaft surface aerators such as Biwater, O2Max, Simcar Aerator by Simon Carves and Simplex Aerator by Ames Crosta.

Features & Benefits


Strong axial flow pattern

Improved mixing and oxygenation and at greater depths to maximise treatment efficiency

High oxygen transfer rates as a result of the above

Improved energy efficiency and lower operating costs

Simple, robust and long-life design

Reduced whole life costs from the long asset life and low maintenance requirements

Platform and float-mounted options

Greater flexibility for easy integration in existing plant designs

Widest aeration turndown

Variations in treatment accommodated without wasted energy

‘Anti-rag’ impeller blades

Reduced risk of performance and maintenance issues caused by rag attachment

Baffles or draft tubes where required

Improved treatment performance in deep tanks


Where are Vertex Surface Aerators used?

Why are they selected?


Aeration tanks

Deep mixing and aeration

Oxidation ditches

Highest efficiency


Reliability and longevity

Lagoons and reservoirs

Availability of floating and fixed units

Clean water oxidation tanks

Temporary hire