The new range of aerators follows hot on the heels of the manufacturer's range of sewage pumps, which were also among the first to meet full requirements for the new EU ATEX European Directive for the protection of workers in explosive atmospheres.
Tsurumi's new range of TRN submersible aerators can be used, among other things, to oxygenate biological waste-water-treatment-tanks. They also conform to the new EN 12255-15 European Standard. This new standard requires oxygen transfer rates to be measured under defined standard conditions that specify oxygen should pass through an aeration tank filled with clean water, at a temperature of 20˚C and at sea level altitude.
"The new aerator series offers a large number of improvements in comparison with the previous range," says Tsurumi product manager Carsten Bode. "There is now no need for a separate blower for installation at 6 m and below; the longevity of the machine has been increased; and every single conductor – not just every cable – has waterproof moulding."
Oxygen input rates measured using old standards are often higher than those with EN 1225-15 specifications. Some manufacturers are still using the old method, so customers buying a new piece of equipment should ensure it conforms to the new regulations to compare like-with-like.
As well as being fully EU-compliant, Tsurumi's new submersible aerators have many design features that will increase the lifespan of the equipment. These include an over-sized oil chamber and leading-edge patented oil-lifter to provide some of the best lubrication around. In addition there are bevelled aerator-casings, which reduce rust by ensuring no water rests on the machine when it is not in operation. The aerators are also made from highly-robust cast iron.
Installation has been made easier as the aerators can easily be put in place with a mobile crane without the need to empty the basin. They also offer a practical advantage as their design means the plant does not need to be totally shutdown while maintenance to the aerators is carried out.
Other advantages of the new aerators are that they can be used to pre-aerate and therefore pre-treat heavily polluted sewage water, and they have the ability to aerate activated sludge basins or neutralise sewage water with C02 or flue gas.
Extensive testing shows the aerators can also deal quickly with algal blooms caused by the eutrophication of lakes, ponds and other natural waters. And the aerators will be an important tool in the flotation process that involves the physical separation of fine-grained solid conglomerates.
The new TRN series will consist of ten models with motor outputs between 0.75 and 40 kW and the first model will be available from autumn 2008, when the production of the old TR/TRN-series will cease.