Wednesday, November 15, 2017

Progress Updates 11.15.17

Progress Updates

Date: 11.15.17
Location: Logan HS
Goal: Research adhesive material to hold thermistors in place and packing material for the humidifier.

We needed an adhesive which would hold our thermistors in place to monitor temperature. The adhesive would need to adhere to both metal and PVC in a wet environment. We contacted Mr. Ed Johnson at NECAL Corporation and described what we needed. Mr. Johnson replied back the same day with the solution you see below and sent out some samples for us to try. Special thanks to NECAL!

Sample sheets of pressure sensitive adhesive

We need to start looking at the packing material to use in the brine tank where heated water will be sprayed. We need something that will allow water to slowly trickle down and collect on the packing material. It also has to allow the warm vapor to rise up and over to the other tank. We are thinking about separate units that can be taken out and replaced. A range hood filter would provide the support surface on the top and bottom of each unit with  humidifier filter material in between.
Sketch of  a packed bed tower unit. Notice how one is stacked on top of the other.

Andy K. had some additional thoughts on how to create a greater temperature difference using the Peltiers.

"Possibly lowering the water flow rate through the block could have an impact on the temperature, and we could also try thermal paste.

In our experiment (if I remember correctly, I might be wrong), I think we were trying to cool the water and remove the heat with the fans.  Maybe we should try heating the water rather than cooling it, or redo the experiment with a smaller, stationary volume of water.

To get condensation to form in the dehumidifying chamber of the HDH, the coil needs to be cooler than the surrounding humid air.  Unless the intake water is fairly cold (which would then mean that we would not have to use a peltier to create a cool condensation surface), I don't think we should bother cooling it down for the condensation coil when it needs to be almost immediately reheated for humidification.

Instead, we could intake water straight into the heating part of the HDH and skip running it through the coil. We could cool the coil as is (empty) or cool a coil filled with stationary water which would not be used in the desalination process.  This would probably end up cooling faster and stay cooler for longer.
To do this, a peltier would have the cold side attached to the coil filled with stationary water, and the hot side on the intake water piping.  This would allow for heat to be transferred away from the cooling coil quickly by the water flowing into the system, and at the same time it would begin assisting in heating the intake water for the humidification tank."

No comments:

Post a Comment

Desalination Project Completion

LA CROSSE LOGAN HIGH SCHOOL DESALINATION MACHINE PROJECT Designed and Fabricated in the Logan Technology & Engineering Department  ...