Oxidation ditches are traditionally aerated using brush rotor aerators, however older designs can give poor mixing at depths, as well as requiring regular bearing attention and maintenance.
Following bearing failure on their rotor aerators, a UK wastewater utility contacted Corgin for help.
Based on its years of experience, Corgin advised that the rotor aerators were replaced with bracket-mounted spiral aerator, which would offer low cost and maintenance operation with well-mixed aeration.
The original suggestion was to replace all four rotors serving the two ditches, but prudence dictated that only the broken rotor was replaced. The performance of the new spiral aerator combined with the reduced power consumption impressed the client. Based on energy savings alone, a very short payback period was estimated.
Six months after the first installation, a second rotor failed and was replaced by another 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 £4000-5000 a time, following not infrequent breakdowns.
The client commented, “These units are saving me a lot of work and helping to reduce our carbon footprint as a business whilst outperforming the old machines”.
As a result of the success of this project, seven other sites in the surrounding areas have also replaced their existing aerators with spiral aerators as part of an ongoing energy and cost saving scheme.