Aeration costs Spiral

The traditional way of aerating oxidation ditches is using good old brush rotor aerators – but alas, often with high power consumption and poor mixing at depth. Bearings need regular attention and maintenance is not easy.

A UK wastewater utility was having problems with bearing failure on their rotor aerators and contacted Corgin (UK) for help. Based on years of experience, Corgin suggested they replace their rotor with a bracket-mounted Spiral Aerator to enjoy trouble-free, low cost and well-mixed aeration, free from bearing problems and maintenance headaches.

The original suggestion was to replace all four rotors serving the two ditches, but prudence dictated that only the broken rotor was replaced. The client was highly impressed as the new Spiral Aerator not only performed better, but also used half the power of the old rotor. Based on energy savings alone, a very short payback period was estimated. Six months later, a second rotor failed and was replaced by a Spiral Aerator. Two further Spiral Aerators have now replaced the remaining two rotors following a capital grant from the company’s ‘spend now to save in future’ scheme.

A recent study by the client to compare the power consumption of the new and old aerators revealed energy savings of over £8000 per annum. Additionally, the new Spiral Aerators require virtually no maintenance whereas the old aerators were running up repair costs of up to £4-5000 a time, following not infrequent breakdowns. Needless to say, the client is delighted, commenting, “These units are saving me a lot of work and helping to reduce our carbon footprint as a business whilst outperforming the old machines”.

A tribute to the success of this project has been the resulting application of 7 other sites in the surrounding area to replace their existing aerators with Spiral Aerators as part of an ongoing energy and cost saving scheme.

Spiral Aerators are used in a wide variety of situations where good mixing and aeration combine in one machine. With their high efficiency and reliability, short payback periods are often possible based on energy and maintenance savings.

Spiral Aerators typically come into their own in applications such as oxidation ditches, lagoons, balance tanks and tanks with high surface areas relative to depth.

German-engineered Spiral Aerators are the maintenance engineer’s true dream – they have no submerged bearings or wearing parts, only stainless steel and GRP components below water level, and the helicoid propeller is designed to prevent clogging with rags or debris.

Corgin also hold distribution rights for high- and low-speed surface aerators, including foam control aerators. This is complemented by the innovative Foam Skimmer which removes filamentous foam and selects against filamentous bacteria; with improved settlement and final effluent clarity as additional benefits.