Design
DESIGN & SPECIFICATION
ETS are experts in the application of Ultraviolet light, offering both medium pressure and low pressure amalgam lamp technologies, allowing for tailored and cost efficient solutions for a variety of applications. Flexible designs ensure ETS can provide advanced technology solutions for both new installations and retrofits, in a range of difficult and challenging environments. With a vast product range catering for a variety of applications from only a few gpm to full scale treatment plants treating in excess of 20 MGD in a single system, ETS can provide effective solutions for any specification.
The use of CFD design tools is now standard practice within the industry. The effect of bends into and exiting a UV reactor has an extremely detrimental effect on the ability of the UV reactor to deliver an optimal dose, and often excess power is required simply to overcome an inefficient hydraulic design. The ETS designs are extensively CFD optimized to ensure that the fluid flows uniformly through the chamber. Baffles are used to assist to provide direction adjustments where required, however excessive use of baffles does increase headloss, cause shadows, and in certain cases can actually entrain air within the reactor.
The flow profile is produced from the chamber geometry, flowrate and particular turbulence model selected. The radiation profile is developed from inputs such as water quality, lamp type (power, germicidal efficiency, spectral output, arc length) and the transmittance and dimension of the quartz sleeve. Proprietary CFD software simulates both the flow and radiation profiles.
Once the 3D model of the chamber is built, it is populated with a grid or mesh that comprises of thousands of small cubes. Points of interest, such as at a bend, on the quartz sleeve surface, or around the wiper mechanism use a higher resolution mesh, while other areas within the reactor use a coarse mesh.
Once the mesh is produced, hundreds of thousands of virtual particles are "fired" through the chamber. Each particle has several variables of interest associated with it, and the particles are "harvested" after the reactor. Discrete phase modeling produces delivered dose, headloss, and other chamber specific parameters.
Once the modeling phase is complete, selected systems are validated using a professional third party to provide oversight and to determine how closely the model is able to predict the reality of system performance. System validation uses non pathogenic surrogates to determine the Reduction Equivalent Dose (RED) ability of the reactors. Most systems are validated to deliver either a 40mJ/cm2 dose or a log reduction of cryptosporidium/giardia within an envelope of flow and transmittance. The US EPA is the standard method used in the United States, while Europe is adopting this alongside the DVGW 294 standard for drinking water applications.
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