1) Disassembly and Reassembly of MED Unit Pieces Throughout Modification Processes

During this semester (Fall 2016) I was enrolled in 1 credit of CHME 498 under Dr. Brewer. The completion objectives for this research were:

1) Disassembly and reassembly of MED unit pieces throughout modification processes.

2) Installation of electric water heater, heat exchanger, and plumbing for additional heat energy supply to the unit.

3) Completion of MED unit shakedown trials after modifications.

I will address each objective in the order they are listed above. I was a part of the disassembly and reassembly process for replacing multiple hoses and a tank drain valve, as well as removing and tightening pretty much anything with threads in an attempt to diminish leaks. The replacement of the cast iron tank drain valve will lead to much cleaner distilled water. A PVC drain valve was chosen because of its resistance to corrosion, and lack of exposure to heat in its intended position. Some of the temperature gauges were removed, calibrated, and had their position swapped. A pump that is suitable for use with brine was ordered and installed after the previous one failed. The vacuum pump was disconnected and taken to Albuquerque for repairs. A three way valve was added to allow for the removal of cooling water. I became very familiar with the McMaster-Carr website.

Now I will address the second completion objective. A submerged screw plug style water heater was installed into the top of the water tank. Due to the large increase in energy supplied by this heater, the unit is now operated without the pre heater and heat exchanger system. To conserve the energy being provided by the submerged heater and pump that also functions as a heater, installation was added to many places on the unit. The sides and back of the first effect were covered in fiberglass insulation. Every hose that we could cover in insulation, was covered in insulation. Now the operating temperature within the first effect has risen, although we have not seen much of an increase in efficiency.

For the third objective, I was a part of numerous runs of the unit using tap water as the feed. What I mostly did during runs was record gauge readings, carried full brine containers outside, held the funnel to pour liquid nitrogen into the cold trap, and addressed problems as they arose. We found and fixed numerous small leaks. I am definitely better at identifying small hissing sounds. I observed the newly refurbished vacuum pumping operating as it should, and learned how to remove the water from the oil mist eliminator.

Additional research is being done into possible water desalination systems for the owner of Pistachioland, Tim McGinn. An initial trip to Pistachioland was made to give an idea of the sampling methods that will be needed.

In conclusion, my participation in undergraduate research with Dr. Brewer’s group this semester has furthered my understanding of the idiosyncrasies involved in the plumbing of the MED unit, corrosion, heat transfer, operations involving a vacuum, and the process of trouble shooting and replacing parts on a prototype lab scale unit.