The zero-maintenance passive Tideflex Mixing System (TMS) has been installed in over 3,000 water tanks, has been extensively CFD- and scale-modeled and has proven to improve water quality and mitigate ice formation by achieving complete mixing utilizing the inherent energy of the distribution system that causes tanks to fill and draw. Passive TMS has achieved complete mixing in tanks with less than 10% volume turnover.
When tanks have extremely low turnover, supplemental active mixing can be used with the passive TMS. A passive TMS can easily be made into an active TMS by using a small recirculation (recirc) pump; with this, you have the Pass-Active TMS.
The Pass-Active TMS has a number of advantages over submerged or floating mechanical mixers. For example, the passive TMS is installed inside of the tank, so no maintenance is required; the mechanical components are located outside of the tank, so they can be easily inspected and maintained. Also, users need only turn on recirc pump when its use is required, which translates to savings on maintenance and energy costs. The pump can be initiated via the SCADA system; is low flow, low head, low energy and low cost (typically <0.5 hp); and can be used for forced drawdown to increase the volume turnover of the tank and reduce water age. In addition, the Pass-Active TMS can also be used for chemical injection (which eliminates the need to climb to the top of a tank), boosting chlorine and forming chloramines.
Source: Red Valve Company and Tideflex Technologies