Page History

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Fix:We can minimize the wall and tube friction by increasing the size of our bench scale experiments.

Sand Properties & Parameters:

We might have used an incorrect D60 and porosity for the filter bed in our equations. We show on the Fluidization Velocity Experiment page how small changes in these values could easily account for the error.
Fix: For the next experiment those parameters should be tested for the sand or material before conducting experiments.

Preferential flow:

Despite our best attempt to keep the test tube as level as possible, we might have introduced preferential flow in our experiment causing an unbalanced backwash flow.
Fix:In the future, this hypothesis can be tested using dye. In addition, precuations can be taken, such as two levels could be clamped on the sides of the filter walls to ensure it is level or also use two clamps, rather than one.

Expansion Headloss:

The accuracy of our model also required the headloss occurring through the expanded bed to be more or less constant, which we did not have time to test (but is part of Recommended Future Research below).
Fix: Testing it would involve putting a pressure sensor into the system, connected on either end of the filter.

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