Filtration Solutions


Change Feed Flow Directions for Uniform Loading of Membrane under Highly Challenged Applications


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Seasonal changes to waterbodies are generally defined by precipitation and temperature patterns during different times of the year. As the weather gets warmer, the density difference between warm surface waters and cold bottom waters increases to a point where two separate layers are formed. This phenomenon, called summer stratification, prevents whole lake mixing creating large algae blooms on the top surface of the water. A common filtration issue is uneven loading on a filter element because of the decreasing feed pressure along the element. This causes the inlet end to foul much faster than the outlet end.  This is especially true when multiple elements are placed in series.  The dynamic flow mechanism (i.e. a dual-vortex flow pattern) induced by the coiled membrane filter (CMF) can effectively address this issue. However, when operating with highly challenged influent, such as algae-abundant surface water during summer time, the uneven loading can still occur.

Our prototype has been tested during periods when the algae blooms are at their peak. Despite these conditions, our CMF technology is able to maintain a high flux rate along with excellent permeate quality. Wondering how our technology is able to maintain such a high flux around 100 gph the entire time during the algae bloom?

In the figures, you can see our prototype flow diagrams and actual images of a filtration system prototype. If you observe carefully you can see the prototype is equipped with two three-way valves: V1 and V2. Both valves are placed over the cover of the permeate tank, you can see them clearly in the second figure.

The reason that we can maintain our flux rate at around 100 gph is that we change the direction of the inlet flow periodically. As a result of changing the flow direction, the chances of experiencing membrane fouling are reduced since the filter loading is uniform (from both sides) over time.

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Hence this filter can perform better in highly challenging environments. The change of flow takes place every several hours depending on the influent condition. Data is available to prove that this technique enables us to achieve required flux rates. Also, changing the fluid flow works very effectively during membrane cleaning and flushing.