Surface Aerators
ROTOX Type

The ROTOX surface aerator represents a valid solution for the problem of aeration in wastewater treatment plants.

The characteristics of this aeration system are in fact:

Great simplicity in the design and construction of oxidation tanks
Oxygen supply capacity easily adjustable as operating conditions vary
Low installation cost
Minimum operating costs
Minimum maintenance
Maximum regularity and reliability of operation.

Fields of application

The ROTOX surface aerator was designed to supply oxygen to activated sludge aeration tanks while simultaneously achieving a significant sludge recirculation capacity.

Therefore, it is optimally used in:

Biological treatment of wastewater in activated sludge plants
Homogenization in pre- aeration tanks
Aerobic sludge stabilization
Aeration of ponds and lagoons

Furthermore, the high flow rate and the ability to create a spray allow the ROTOX aerator to lower the temperature of the pumped water as a function of the external temperature.

The aerator can be installed fixed on a walkway or mobile on a floating pontoon constructed from carbon steel, stainless steel, or with fiberglass floats

Impeller

The impeller, constructed in carbon steel or stainless steel, can be supplied as a semi-enclosed type with wide channels that ensure a significant suction capacity for taller tanks, or as an open, non-clogging type with high pumping capacity and the ability to adapt to different operating conditions.

The design of the impellers allows the absorbed power and the quantity of transferred oxygen to be varied by modifying any of the following parameters:

Direction of rotation
Adjustment of the immersion depth
Variation of the rotational speed (RPM)

By combining these factors, an adjustment is achieved that can vary from 30 to 100% of the maximum oxygen supply.

New Impeller

The new semi-axial flow OV impeller, born from 3D computer graphic design and testing in a trial tank, responds to the need to find a solution to the problem of clogging in traditional closed-type impellers while simultaneously ensuring a high efficiency of oxygen transfer to the water.

This new impeller is ideal for tanks with a high content of rags and un-screened solids, combining non-clogging characteristics with high oxygen transfer efficiency, while ensuring the mixing of the entire tank.

The design of the blades makes them immune to solids and rags and guarantees a shredding effect on coarse solids present in the tank.

Given the great flexibility of the new impeller, by varying the diameter, the rotational speed (RPM), the size of the blades, and the angles of the blades themselves, it's possible to achieve the best operating point for the required quantity of oxygen input.

The central conical section, which provides a hydraulic seal, guarantees a buoyancy thrust to the impeller, reducing the axial and radial loads weighing on the gearmotor and the walkway.

Cooling system

The high pumping flow rate and the ability to create a large spray make the ROTOX aerator capable of lowering the water temperature in processes where this is necessary.

Special impellers particularly suited for this purpose have been designed and manufactured to maximize the spraying capacity.

Power

The motorization is achieved through the use of a gearmotor unit suitable for outdoor installation, with a degree of protection adequate for the environmental conditions.

The power absorbed by the motor varies depending on the immersion depth of the impeller, and the maximum power is reached at 100% immersion.

An impeller immersion adjustment frame is supplied upon request.

Installation

The surface aerator is suitable for installation in square-plan tanks and has its own zone of influence where correct mixing and oxygenation are guaranteed, and this depends on the model, the impeller diameter, and the specific power.

The maximum water depth in the tank depends on the impeller diameter and must have a ratio with the tank side no greater than one third.

Floating installation

In tanks where walkways for aerator installation are not present, such as in tank/pond with waterproof liner, it's necessary to use a floating installation with mooring ropes.

The flotation system is a three-arm type with ballasted buoys to improve operational stability and can be supplied in the light and standard version.