An independent study from the British Hydraulic Research Group (BHR) has shown how a new design of static mixer can make a positive impact on the purification of potable water.
Addressing the age-old application challenge of trying to achieve a high degree of mixing in a compact space, tests by BHR have demonstrated how Chemineer’s Kenics Ultratab can produce a Coefficient of Variation (CoV) lower than 0.05 at a distance of three mixer diameters (3D) downstream from the mixer.
This CoV, a measure of mixing degree, is achieved by a design that introduces the additive directly before the mixing tab where it can dilute rapidly into the water stream. With low pressure drop enhancing the energy efficiency of the process by saving on pumping costs, the additive is blended very efficiently as well as quickly.
The integral wall injector that is located upstream of the Ultratab mixing element forces the additive through the high energy dissipation region (created by the mixing element) to provide vastly superior mixing results.
Irfan Rehman from Chemineer, commented: “For engineers and operators working in potable water applications, the introduction of this new mixer means no longer having to compromise on the level of mixing and blending technology to save space, which tends to be at a premium at most water treatment works”.
He added: “For turbulent flow mixing applications, there is now the considerable benefit of complete blending over short distances downstream of the mixer, as well as the advantage of being able to carry out an installation in a compact space”.
The particularly short length of the Ultratab, less than one pipe diameter in many cases, also helps optimise plant layout because the flanged spool includes the additive port and the mixing tab or element.
Irfan Rehman continued: “Mixing in a short length with this new design avoids costly over-dosing and allows much better management of the process by allowing more chlorine residual control, more efficient coagulation and shorter pH control loops”.
Under testing by the British Hydraulic Research Group, it was showed that Ultratab can help engineers across all requirements:
- Mixing of pH-adjustment chemicals in water
- General mixing of chemical additives into water
- Acid Dilution prior to injection
- Mixing Flocculation Agents into water
- Mixing coagulants into water
- Mixing Sodium Hypochlorite and chlorine solution into water
- Mixing Polymer solutions into water
To meet potable water requirements, this new static mixer is also coated with a form of ScotchKote, and is available in Fibre-reinforced plastic, Duplex, Super Duplex and Hasteloy.