Defender® will work with perlite or diatomaceous earth (DE). Neptune Benson prefers the use of perlite based on its superior particle removal, lower cost, lower turbidity levels and safer handling and disposal.
The initial capital cost of a Defender® system is more than a sand system but is quickly offset in operational costs savings – often in less than a year. The smaller Defender® system saves on construction costs, water and waste costs, energy and chemical costs as well as power costs.
No, there is no pool size limit. Defender® may be installed on 70 – 2500 GPM (single filter) pools and spas. Multi tanks can be installed in tandem to accommodate higher flow rates.
Defender® filters are programmed to complete the automated regeneration cycle daily and it will take no longer than 10 minutes. This includes the “bumping” step and agitating the media. (See also “Bumping”)
“Bumping” is the mechanical movement of the tube sheet which forces water into the tubes, evacuating the media from the surface of the tubes, sending it into suspension. It is accomplished by mechanical movement of the septum up and down within the water in the filter housing. This motion expels the media and dirt particles from the septum and into suspension. This allows the filter elements to receive a fresh coating of perlite once it re-attaches itself to the tube elements. Defender® filters are programmed to bump daily and will take no longer than 10 minutes to complete.
Every Defender® system is designed to be fully automatic but is operable in semi-automatic mode which requires the push of a button to initiate the automatic filtration and bump cycle.
Defender’s programmer includes auxiliary contacts to control all peripheral devices.
The complete filter cycle using the same charge of perlite usually averages 4 weeks depending on bather load. Some pools may go months in the off-season.
Eliminating used media and recharging with new media in a single Defender® takes 15 – 25 minutes.
There are three main differences: lamp power, electrical efficiency, and the type of UV light produced. Each lamp type is best suited for different applications, which the Neptune Benson engineers will be pleased to explain to you.
UV dose is calculated from the flowrate, the water transmittance and the lamp power. The dimension of UV dose is m J cm-2. Neptune Benson uses advanced Computational Fluid Dynamics (CFD) to accurately predict the UV dose that the water will receive, and then systems are validated by a third party test house to verify the predicted UV dose closely matches the actual delivered UV dose.
UV transmittance (UVT) is a measurement to determine how much UV light passes through a sample of water compared to distilled water. Dissolved organics, suspended matter, color, and certain UV light absorbing metals are the main absorbers of UV light. It is the key factor in properly sizing a UV system to operate effectively.
FAQs November 5, 2014