Still no chlorination

13 May 2008

Today has been an interesting and frustrating day. We were up early to get working. Paul brought a new inverter with him and I was anxious to install it. We were also excited to try the chlorination system that had been designed. After reading the instructions for the inverter, I took the time to install is correctly and after connecting the last wire from the batteries, it made a bright spark, followed by numerous loud pops followed by billows of smoke. Jim Trimby (who arrived later in the day) said that, “inverters are powered by compressed smoke. When they lose their smoke, they just stop working.”

I was not quite as humorous about the event. This is an expensive piece of equipment. After taking a hard look at what I had done, I realized that I had wired the inverter for a 24-volt system and it was meant for a 12-volt system. It completely fried the system. It was completely my fault. I was devastated by my mistake. It was not only a costly mistake, but I doubt we can replace it before I leave.

I decided that the next best place to go would be to assist the others in getting the chlorination system working. After quite a few hours of pipe assembly and discussions of hydrodynamics (of which I know little) we found that our ideas simply did not work. Mark Bacaro had an idea where we run a plastic hose inside the larger inlet pipe with tiny holes cut into the plastic pipe. The fluid running over the smaller hose would then pull out the bleach and give us chlorination. I did not think it would work but I suggested he try it. It failed.

After a fairly dismal start to the day, it was time to head back out to the airport to pick up Jim Trimby. Jim is a construction worker and is a member of the RAM Airborne team. He is also an EMT-B and a climber. He has been a friend of Ricki and suggested she volunteer with SOAR.

On the way back to Manari, I ran into our pilot, Terrance. Terrance told me about a patient in Aishelton who was being considered for medical evacuation. He knew little about the patient but said that they were concerned because she was pregnant and had swelling of her feet, hands and face.

This sounded like a possible case of pre-eclampsia. This is a toxicity of pregnancy that is characterized by swelling of hands, feet and face, as well as headaches, visual disturbances and hypertension. When the process progresses to full eclampsia, the patient seizes and the lives of both the mother and the fetus are in danger. I suggested that she be immediately evacuated to Letham and that she might need a magnesium sulfate IV drip for the trip. I offered to fly with him and he agreed.

So I quickly drove back to Manari to drop of Jim, and then headed back into town. I stopped by the hospital where they gave me IV solutions, needles and some vials of magnesium sulfate. Then I went to the airport to meet Terrance.

The flight to Aishelton was about an hour long. The patient was waiting at the airport. As we approached the dirt runway, there were numerous cows on the runway, so Terrance buzzed the airfield to scare the cows away then turned around and landed.

Assessment of the patient showed found a 14 year old pregnant woman who did not know how long she had been pregnant, but looked as if she was at least six or seven months along. Her blood pressure was fine and she denied any visual disturbances. However, I decided to start a IV on her and have medications available in case she started to seize. Then we loaded her up and took her to Letham. It was an uneventful flight.

I arrived back at Manari just before sunset. Our cook had returned (yeah!). We still did not have chlorination and the inverter was still broken. However the team had come up with a new idea for the chlorination system.

They have a 12-volt propane shut off solenoid that they intend to install at the tank. Instead of running propane through the solenoid, they will run pure bleach. It sounds simple. However, the power at the tower is 24 volts. I am also concerned that the bleach will quickly cause corrosion to the brass interior and the solenoid may fail quickly.

So as night has fallen, David Batt and Ricki Sheldon have been looking at Ohms law to figure out how to reduce 24 volt to 12 volt. To make it more challenging, the DC power wire to the tank is a 150-foot length, so the power will have already dropped so they will have to consider that when finding a way to reduce the voltage. Tomorrow is sure to be another day of intellectual conversations about resistance instead of hydrodynamics. If we needed to build a traction splint from scratch, I would have it done in a second, but much of this work is beyond my expertise.

Near the end of the evening, I called a friend of mine who is a scientist; Ralf Moir. I was hoping I would be able to give him some of the specifications of the solenoid we are planning to use and see if he could determine if it would be possible to hook it to a 24-volt system. I was surprised to find he had been following the blog and was aware of what we are doing. His suggestion was to hook up two of these12-volt solenoids in series and that would solve the problem. If we had two solenoids, we would do it.

I mentioned his solution to the rest of the team and they thought it was a good idea and started to expand upon it. They are now considering removing a 12-volt component out of our 4WD Suzuki and running that in line with the solenoid and seeing if that will work.

As for me, I am willing to try a few more unconventional ideas from the team. I have promised them that if we get chlorination running, that I will buy steaks for the whole team. I hope to be having a steak dinner soon.

PS – Message for Ralf Moir. You requested more detailed information about our system. Here it is.

We have four 185-watt solar panels running at 24 volts into a 30 amp solar controller. We have eight 12 volt deep cycle batteries connected in a 24-volt system that are also connected to the solar controller. The load from the solar controller is a 24-volt load that runs directly to the submersible water pump in the river water intake pipe. A float switch is wired on one side of the power circuit and is currently installed in the water tank. The system was designed as a 24-volt system due to concerns of voltage drop on a DC power run that exceeds 300 feet (almost 350).

Water is pumped from the river approximately 150 feet to a water tower with a total climb of about 60 feet. The system from the river to the water tank is ¾ inch PVC pipe. The water tank is 400 gallons.

We are looking to chlorinate the water before entering the water tank or at the water tank so that there is plenty of contact time.