Test device the second

We proudly present: The finished plant

The SoWaDi team could only dream of a SoWaDi device in Darmstadt where long-term measurement data can be collected and change ideas can be quickly tested. Thanks to the TU Darmstadt, which kindly provided us with a place on the experimental field at campus Lichtwiese, we were able to fulfil our wish on the weekend of June 14th to June 16th (exactly one year after the last setup).

The project team met on Friday to check the previously purchased materials and to discuss the course of the weekend. On Saturday morning the construction started energetically. In order for everything to go smoothly, groups were formed in advance to take care of various parts of the system. So, the team started working parallel on the stand, the absorber box and the pipe bending. In the afternoon, pipes and aluminium sheets were joined and sprayed black. Sunday was reserved for the construction of the intermediate and upper frames as well as the final assembly.

One of the additional goals for this setup was, to examine the improved version of the instructions and test it in practice so that any further adjustments could be made. All suggestions for improvement were therefore noted diligently and evaluated in the subsequent meetings. Especially the filling of the pipe with sand and the following emptying led to problems again and raised a discussion concerning other possibilities.

Filling the pipe with sand proved to be a huge challenge.

In contrast to the previous systems, it was decided not to place the copper pipe in deep-drawn sheet metal this time, but only to place the copper pipe on the surface of the sheet metal. This is to test whether the very time-consuming deep-drawing of the sheets is worthwhile in terms of water output. In addition, a measuring technique designed by the team was attached to the system. The measurement targets include the energy input, the maximum achievable output quantity and the influence of short-term clouds on the output. In the future, verifiable predictions about possible output quantities and times should be possible.

Thanks to the 15 motivated helpers, the construction was successfully completed. Many new faces at SoWaDi were also able to get to know the device and the instructions properly for the first time and observe how the first surge of disinfected water flows from the specially built device. The setup and recording of the measurement data was very informative and opened up new work packages for our project work.

The finished system is located on the Lichtwiese campus between the buildings of the Architecture Department and the Darmstadt Climbing Centre. Interested parties are warmly invited to peer through the fence and find out more about the research project here on the homepage.

The pipe was connected to the metal sheets and placed inside the insulated absorber.
The happy team after finishing the construction

Built-up of a SoWaDi Plant

Over the weekend (06/15 – 06/17 2018) it was time again for the members of SoWaDi to meet for further tests regarding the renewed construction of the plant. In order to accomplish this, our team built up the whole device within two days. The main focus was on bending the aluminium sheets, copper pipe and the glass front of the absorber. In all three cases, extensive changes in implementation and quality have been made in recently which were finally audited for their efficacy.

The SoWaDi team after finishing the assembly of the plant

The copper pipe is being connected to the metal sheets

For the bending of the sheets, the new and oversimplified deep-drawing device was used. This allowed the sheets to be processed faster and much quieter (without hammering).

Also, the newly introduced sand filled copper pipe was used in during the construction to prevent constrictions during bending. The first hurdle was to completely fill the 10-meter pipe with sand and, if possible, without entrapping air inside, unfolding the coil and putting too much strain on the material itself. This was achieved by using a ladder and gently shaking the entire tube. All the effort proved to be worthwhile as the pipe remained completely intact without any constrictions by the time of its implementation. The removal of the sand could also be solved elegantly by rotating the construct like a stirring wheel after connecting the tube to the aluminium sheers.


Installation of the glass cover

The innovation of the glass front was to divide the bottom of the glass panes horizontally into several sections. This approach is intended to better distribute the thermal load and to mitigate the risk of the glass cracking via thermal expansion.

In the coming weeks, the system will be tested for its performance. In order to accomplish this the temperature of the water output and the solar radiation will be measured.

Preparations for the rebuilding

At the regional group weekend from May 25th-27th the motivated participants met once again in Mossautal at Haus St. Michael. The SoWaDi team used the time mainly to prepare for the upcoming construction of a SoWaDi plant in June. In order to have a successful reconstruction on June 15th-17th, a schedule was drawn up, which states which team will take over which tasks over the weekend and which tasks have to be completed in advance. Additionally, the last changes were made to the instruction manual and their corresponding actions were optimized accordingly. After the individual team work, the group found themselves back together to clarify what they should expect to accomplish. Besides the intensive work with one another, there was still enough time to share the results with the entire regional group.

A part of the team planning the construction of the plant

New tools for the installation

Bending the sheet with the new deep-drawing device

On January 13th, members from SoWaDi met at the University’s campus to test some changes they have been considering for the past few months. In hopes of supporting the system’s new development, the focus of the day’s assessment was fixed on two important prototypes: the pipe-bender and the deep-drawing device. Additionally, the surface of the plexiglass was evaluated.

Before Christmas break, small groups from SoWaDi had formed to consider what changes could be implemented to improve the efficacy of the system. An initial test in Tanzania the previous year had revealed that bending the pipe and processing the sheets needed for the system’s construction were not consistently precise. To bend the pipe, the group had already filled a copper pipe with sand during the Regional-Group-Weekend. This approach gave favorable results with a short pipe, and was further investigated on whether this principle could be transferred to a pipe of eleven meters in length. After the pipe was filled laboriously-intensive with dried sand, a newly built pipe-bender was used to evenly shape the pipe into the best possible form without any constriction. Despite the group’s success with the sand-filled pipe, they soon had learned that it was much more difficult to get the sand out. Therefore, the group is still considering the efficacy of this approach and is keeping other options in mind.

However, for the deep-drawing device, a completely new approach was taken: the sheet was clamped down with a few screw clamps and then bent manually around a metal tube with the aid of a lever. In order to compare results, the small group conducted another test with the previous deep-drawing device.

A third small group investigated whether Plexiglas could be used instead of glass panes to cover the absorber box. The team tested the scratch- and heat resistance of the new material.

It still remains unclear to which extent these new concepts will be used in the future when the team returns to construct the system next year in Tanzania.

Testing the pipe bending device

The copper pipe is filled with sand to avoid putting a too heavy load on the material while bending it.

On November 3rd, the SoWaDi team and the rest of the Darmstadt regional group of Engineers without Borders traveled to the St. Michael Guest House located in Mossautal, a small village situated in the Odenwald.

Regional Group Weekend – Along with the opportunity to play games and having fun getting to know one another better, the team also had the chance to work more intensively on their project. In addition to the long-term planning of SoWaDi’s development goals, the main focus of the weekend  was to improve the effectiveness of the pipe bending device: Lying at the heart of the current project phase, a few minor construction vulnerabilities of the plant that were discovered from the last visit to Tanzania in January are being evaluated. It is of particular interest that all of the new implementations will be easily understood by those constructing the plant in Tanzania who lack the context of the new design process. Improving the pipe bending device will aid in efficiently bending the copper tube situated underneath the absorber in which the disinfected water will travel through. In Tanzania, it was also discovered that a slightly thinner copper pipe contributed to kinking of the tube which reduced flow and output of the plant. To mitigate this problem, several solutions have been developed and were tested during the Regional Group Weekend which was not only fun for all the team members but also proved to be successful in moving them closer to their goals.

The bended pipe is checked for constrictions.

Now, all that is left is to evaluate is to see whether these solutions are practical to apply for the full length of the pipe. Results of this development are planned to be announced later this January when whole sections of the plant that integrate these new features will be reconstructed. This outcome was a result of the long-term planning discussed during the Regional Group Weekend. Until April, the focus will be on repairing all of the system’s vulnerabilities in which, till then, will conclude the current phase of the project. Afterwards, the departure to test these implications abroad for the beginning of 2019 will be planned.

Presentation in the Wackerfabrik, Darmstadt

Picture gallery in the Wackerfabrik

Picture gallery in the Wackerfabrik
Picture gallery in the Wackerfabrik

On the 5th of May Tim and Elli held a presentation at the F3 (Wackerfabrik, Darmstadt) inform about the SoWaDi trip to Tanzania this January and to raise awareness for development cooperation. They showed lots of photos and videos from the work in Tanzania and outlined the SoWaDi project. Afterwards there was a lively discussion with the approximately 40 attendees. There was also traditional Tanzanian food to top the event off. The proceeds are going to the SoWaDi project.

In the coming week there will be a picture gallery of the last project phase open to the public.

Evaluation process

Four weeks after our return to Germany we are currently busy with the evaluation of the project phase. All the data we collected is now being analyzed and classified, so that we can come to our final conclusions by the middle of April.
The next step for us is to identify and incorporate all the changes based on our findings, both in the system and the construction manual.

Our team is very motivated and eager to get forward, especially because we got some great water test results from Tanzania! A sample of treated SoWaDi water was given to a water laboratory and the results show that all the bacteria was killed during the treatment. This makes it official, the devices are working the way they are supposed to.

The Malage VTC uses the devices daily and takes precise care of it. The students clean it regularly and improved them a bit already. In addition we receive a report on the condition of the device and the amount of treated water every week.

Saying farewell to Malage VTC

Even after Elli’s departure there was a lot to do. First, there were some things where we had to fix and improve the devices, we attached transparent tubes to the containers to make it easy to read the current water level. We also continued to conduct microbiological tests and measured the amount of treated water in addition to different environmental parameters like temperature and sun radiation. Back in Germany we want to validate and improve our thermodynamic model of the device using this data, e.g. to improve the forecast of how much water can be treated with one device.

Lawrence Mwonyonyi and Ndiko Mwamakula from the Kilimanjaro Youth Development Association take a look at the device

Saturday we were visited by Lawrence and Ndiko at the Malage VTC. They are active with the Kilimanjaro Youth Development Organization to improve the lives of youths with problems that are often related to drugs. Both were impressed from the devices and would like to form a partnership. One possibility would be to educate youths in building SoWaDi devices.

Lawrence also told us about his employer Gongali Model and their product, the NanoFilter. He invited us to visit them in Arusha. Even though a NanoFilter has some advantages over SoWaDi regarding the amount of treated water per day and the initial cost, he likes the SoWaDi approach a lot and sees our major advantage in the fact, that the water is really boiled. Boiling water is a widespread and acknowledged way to treat water so there would not be a need to convince people.

A borehole in a village close to Mwanga supported by the Rotary Club Mwanga

Digging a well at the school farm

After the meeting with Lawrence and Ndiko we visited a borehole-drilling in a village close to Mwanga, that is being financed by the Rotary Club Mwanga. Then we went to the school farm, where a well is currently being hand-digged.

Tim and Ludwig giving a workshop on the construction and working principle of SoWaDi

On Monday we gave a workshop for the students and some teachers on how SoWaDi works and which parts of the construction are essential and should not be changed. Gasiano supported us by translating everything to Swahili. The students were really interested and asked a lot of questions.

Simon Mwakalinga from ACRO visits us at Malage VTC

Following the seminar we had a visit from Simon who works for the Africana Community Rehabilitation Organization (ACRO). We had already met him in Moshi two weeks ago. He also liked the devices and is open for a cooperation.

Saying farewell to Malage VTC – from left to right: Ludwig, Tim, Anderson, Sechelela, Gasiano and Samson

Before we departed from the Malage VTC, we talked about the responsibilities with Gasioano and the two teachers Sechelela and Samson. Sechelela will conduct microbiological tests of the input and output water every month and Samson will take care of the devices themselves and send a weekly report about their condition and the amount of treated water.

After arriving in Arusha we visited NanoFilter, who gave us a very interesting insight on the functionality, the production and also the distribution og the Filter. A NanoFilter is able to treat approximately 10l of water per hour and filters mud, microbes, bacteria and even fluoride.

Thursday morning we had a second meeting with CAMARTEC, this time with Noela Byabachwezi, Director of Technology Transfer. She also sees the main advantage of SoWaDi in the fact that it really boils water, which is a trusted method to remove bacteria. We already talked about a possible cooperation between us and CAMARTEC. They are definitely interested in this technology and could for example assess the market for such a system and help with the distribution.

On the way to the airport stopped in Usa River and paid Eliet Senkoro a short visit. After a long flight we are all safely back home and the evaluation of the last four weeks starts. We will take a look at the building process, review the construction manual, calculate the real material cost, look into ways to reduce this cost and develop a strategy for the continuation of this project and a possible distribution.

Second device, water tests and inauguration

... and the second device

Welding the metal rack
Welding the metal rack

Elli introduces the second group to the construction manual
Elli introduces the second group to the construction manual

The second SoWaDi device was built this week by a second group of students. We were able to use our experience from the first construction and the students were able to take a look at the first device. Because of this and the fact that we were able to reuse the self made tools for pipe bending and deep-drawing the second construction was already finished after only three days. The wooden rack was replaced by a steel construction, which should be more durable and was only slightly more expensive compared to the timber version.

Elli conducts microbiological water tests
Elli conducts microbiological water tests

Parallel to the construction Elli conducted microbiological water tests with the first device and the results show great success: there is bacteria in the input water, but the device was always able to completely remove these and there was no bacteria found in the output water.

After these successful tests we were able to celebrate the inauguration of both of the devices on Friday. The students received two signed footballs from us for their hard work and took some group photos.

Later Elli took the bus to the airport to go back to Germany. In the coming days Ludwig and Tim will meet with some NGOs, more tests and also give a workshop on the functioning principle and the construction of the device.

Commissioning – SoWaDi works

The completed device draws attention

Clean water from the device
Clean water from the device

After the group of four students and one teacher of the Malage VTC finished constructing the first device on friday, we were able to put it to use on saturday. The input tank was filled with water from a cistern and the device correctly positioned so that it faces the sun. We were very happy, when the device started to push boiling water in the output container at the predicted time. We can now safely say that SoWaDi also works as expected in Tanzania. In the afternoon Elli gave a workshop on hygiene and water safety.

Elli is giving a workshop on hygiene
Elli is giving a workshop on hygiene

Ludwig checks the measuring equipment
Ludwig checks the measuring equipment

On sunday we equipped the device with measurement electronics and started more comprehensive tests. Unfortunately one glass pane broke during the assembly of the device and some of the connections are still leaking. This will be fixed in the coming week before we can celebrate the inauguration of the device. We will also continue to conduct tests, both microbiological and regarding the output and other parameters like temperatures and sun radiation. We will also start building a second device with a second group of students. We will try to use our experience from the first construction to already build a slightly improved version.