Splash and Turbine Aerators
OxyTurbine air turbine uses the twin physics principles of precession (as applied to rotating fluids) and centrifugal force. Precession creates a low-pressure zone within the subsurface rotating turbine that draws in surface air from the atmosphere. Once inside the turbine chamber, this air is discharged rapidly into the surrounding water through the power of centrifugal force.
There are two important factors that distinguish turbine aerator from other aerators. First, the centrifugal force slings the air outward at a high speed in a lateral direction more than a 100-foot diameter. Second, tests in a clear water tank have shown that the dissolved oxygen is also pushed downward for ten feet or more below the surface. These forces create a mixing action that disperses the dissolved oxygen throughout the pond. Of great significance, many of the oxygen clusters have been measured to be less than 0.25 millimeters in diameter. This “bubble” size in the water is much too small to be seen with the naked eye even in a clear water tank. Such small clusters have a tendency to migrate from areas of high concentration, such as near the rotating turbine, to areas of low concentration. This phenomenon helps disperse the dissolved oxygen throughout the pond well beyond the 100-foot radius referenced above.
OxyTurbine, air turbine aerator, requires no routine maintenance. There are no bearings to grease or performance adjustments to be made. The floating aerator uses foam-filled; UV-protected, polyethylene pontoons guaranteed not to sink. The motors are heavy-duty, industrial-grade, designed to run 24/7. The air shaft is made of a stainless steel tube that has a ¼-inch thick wall. The rotating turbine is made of fiberglass resin that is both corrosion and wear resistant. The aerator prefers to be left alone once it is turned on, i.e. no need for regular inspections. See the image of the turbine on this page.
Splash aerators attempt to oxygenate ponds by throwing vast amounts of water into the air. The hope is that the water will pick up atmospheric oxygen as it falls back into the dugout. The challenge is that the exposure time of the water to the air is too short for optimal oxygen saturation of the water droplets. Also, these aerators tend to aerate only the top surface of the pond with a rather large air bubble that escapes quickly back into the atmosphere. A further shortcoming is that splash aerators have a very limited ability to disperse the dissolved oxygen in a lateral direction around the pond. Finally, because water is heavy and dense, it takes enormous amounts of energy in the form of large, costly motors to throw the water into the air.
In contrast to the above, the turbine aerator is a state-of-the-art aerator that oxygenates by injecting air into water and not water into the air. It takes a lot less energy to push air into water compared to water into the air. This is the reason the turbine aerator can outperform competing aerators having up to seven times more horsepower.
There are other side benefits to the Turbine aerator. In climates where freezing weather occurs, splash or paddlewheel aerators tend to freeze and must be shut down. The OxyTurbine aerators are not affected by such freezing weather and can continue to operate year around. Another benefit is the savings in electrical costs over competing aerators as discussed below.
Regarding the surfactant issue: OxyTurbine principals have had some experience with surfactants in water that was oxygenated. It likely is impossible to eliminate the foaming issue entirely. However, foaming seems to be much less of any issue if the injection and mixing of the air are performed on the surface. Any splashing or thrashing of the water at the surface tends to exacerbate the foaming of the surfactant.
Electrical Cost Savings
Some clients are reporting a drop in electrical costs of as much as 50% when they replace their existing aerators with our aerators. Surprisingly, this reduction in electrical costs is occurring even as the dissolved oxygen levels in their ponds are rising significantly. Such results are seemingly impossible given that the aerators being replaced have up to seven times more Horsepower than the Turbine aerators. These results stem partly from the inefficient, outdated aerators these clients are replacing as well as from the superior performance of the turbine aerators.
Because the turbine’s superior performance is straightforward. The turbine combines the best principals of fine bore bubble diffusers with the mixing action of prop aerators. Stated differently, the turbine’s rotating blades shear or slice the oxygen bubbles into sizes that typically are only seen in fine-bore bubble diffusers. Unlike such diffusers, however, there are no emitters that can clog, plus the turbine actively disperses these micro-bubbles around the pond in a manner not possible by a static diffuser. The turbine further combines turbulent flow at the surface with the laminar flow at depths. This laminar flow causes some of the deep water to rise to the surface, being escorted upward by the slowly rising air bubbles. At the surface, this water is oxygenated before it once again drops to the lower levels of the pond.
While it might be useful to speak of pounds of oxygen per hour or per horsepower hour, these terms often overlook some very real issues of oxygen saturation, not to mention the financial considerations facing the plant manager. The more important and often ignored keys of a good aerator are:
1.) bubble size and buoyancy,
2.) oxygen dispersion rates,
3.) motor horsepower and attendant electrical usage,
4.) maintenance and repair costs,
5.) ease of removing and replacing the aerator into the pond as needed, and
6.) the availability and cost of replacement parts.
These are the areas in which the OxyTurbine aerator can greatly outperform its competition, particularly regarding electrical usage.
Existing splash aerators of 75 to 100-horsepower, if operating at a full amperage load, would draw between 70 and 90 amps, respectively, at 575 volts. This equates to 40,000 and 52,000 watts each (Eg. 70 amps x 575 volts = 40,250 watts). In contrast, each of OxyTurbine 5-horsepower aerators, if operating at a full amperage load, would draw five amps at 575 volts. This equates to 5 x 575 = 2875 watts. As seen below, we recommend a minimum of 3 of its aerators to replace each of the 75 hp splash aerators (15 hp total replacing 75 hp). Three aerators at 2875 watts each equates to 3 x 2875 watts = 8625 watts. Based on wattage alone, the three Turbine aerators would pull roughly 8625 w/40,000 w = 21 % of the electrical power of a 75-hp splash aerator. This analysis assumes the same operating time and the same kilowatt-hour electrical cost in both situations.
Regarding the 100 hp aerators, we suggest that 4 of its aerators be used to replace these larger splash aerators (20 hp total replacing 100 hp). Based on wattage, 4 Turbine aerators would pull 4 x 2875 w = 11,500 watts. Thus, four Turbine aerators would pull
11,500 w/52,000 w = 22% of the electrical power required by a 100-hp splash aerator. It should be obvious that even if more Turbine aerators are needed than is being recommended, the SAVINGS IN POWER COSTS alone will pay for the OxyTurbine aerators in short order.