Fun Facts about Tube Floc
What is a floc?
Dirty Floc is an aggregation of dirty particles in the water. Particles are moving at different speed in the tube (as shown in the figure below) and cause particle collisions, thus forming "flocs". Our goal is to form as many flocs as possible, so that they precipitate out in the sedimentation process.
What is a tube floc?
The tube flocculator in the lab allows us to investigate the flocculation process in particular. Using Process Controller, we can isolate all parameters of flocculator in order to understand how each parameter affects the process.
Major Components
- Computer with process controller installed
- Alum stock solution
- Clay stock solution
- 3 pumps for alum, raw water, and clay solution
- Influent and Effluent turbidimeter
- Elongated vertical flocculator
- Settling column (long glass tube)
- Pressure sensor
How many setup do we have currently?
So far, we have two setups as you can read here and here.
What cool experiments have we done so far?
We've done so many cool things. Apart from collecting settling datasets to the process controller and analyze them, we also took videos and planning to track how the particles move and behave.
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- Make sure all connection is tight.
- Make sure that there is no clogging in the flocculator and pump tubes
- Get rid of bubbles in the flocculator tube
- Check the pump tube size and the setting on the pump panel
- Check if the tube all goes in the correct direction, especially if you have made changes with the tube setup
- The connections cables connecting pump and the computer are easily unplugged, so check them out!
Major Components
- Computer with process controller installed
- Alum stock solution
- Clay stock solution
- 3 pumps - alum, raw water, and clay solution
- Influent and Effluent turbidimeter
- Elongated vertical flocculator
- Settling column (long glass tube)
- Pressure sensor
Stock preparation
| Amount of water (L) | Amount stock added (g) | Stock concentration (g/L) |
Clay | 11 | 22.2 | 2.02 |
Alum | 11 | 16.5 | 1.5 |
Humic acid1 |
| 0.375 | 0.0035 |
...
- Always check tube connections and make sure there is no clogging in the connections.
- Check the stock solutions. Make sure that there is no sedimentation occurring in clay and alum stock solutions.
- Check the influent turbidimeter. If it displays lower turbidity, then check the clay and alum stock solutions. Check if the flow coming out of the pumps. Check clay/alum flowrates with timer and graduated cylinder. Change in the process controller so that it will give correct value of clay/alum.
- Check bubbles in the floc flocculator and settling tubes, especially at the influent entrance of the settling tubecolumn. Flocs could get trapped in the bubbles and get broken.
How to manually clean tube flocculator? (Credit to Monroe)
After you run many sets of experiments, the particles get attached and accumulate in the flocculator tubes, so it's harder to observe what's going on in the tubes and might break up flocs.
Procedure:
- Turn the Process Controller OFF
- Prepare a small peg by the size of tube inner diameter by cutting the sponge
- Insert the peg at the starting point of the tube flocculator
- Press the pressure bottle (200kPa) to move the peg in
- Turn the Process Controller ON (State 2 - Clean Flocculator)
- Watch it does its magic
- Turn the Process Controller OFF when it almost reaches the end of tube.