Fluidization Velocity Experiment-Single Media

Purpose

Purpose of this experiment is test the validity of the empirical Fluidization Velocity Equation.

Concept of Experiment

Figure 1: Fluidization Velocity Experiment-Single Media Diagram

Results and Discussion

Figure 2: Calculated Fluidization Velocity vs Actual Fluidization Velocity

We had mixed results with regards to Weber's equation for filter bed expansion. At low levels of filter bed expansion, the Weber equation accurately predicted the fluidization velocity required to achieve the targeted bed expansion. As the target bed expansion increased, so did the degree of error. At 9% expansion, the degree of error was at 14%. At 38% expansion, the degree of error was at 37%. As expected, higher fluidization velocity is required for higher degrees of bed expansion.

We believe the following to be sources of error.
>> Human error: Despite our best attempt at being consistent, there will always be human error in observing the bed expansion visually.
>> Wall Friction: We can attribute the increase in error as flow rate increased due to the increase in wall friction on the test vial. We can minimize this 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.
>> 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.