During the 2014-15 school year, we developed a team of students, lead by DJ Swan, who worked to improve the quality and efficiency of the roof tile building process in rural Nyange, Rwanda. We created a mechanical device, freeing them of an otherwise time-consuming and tedious proactive. We partnered with an NGO, PICO Rwanda, the University of Rwanda, and leaders in the community.
The Tile Press is a three step process. First, the workers take the clay from the mixer and define the proper amount of clay per tile by placing it in an empty box. Next, they take the clay from the first step and put it on a mold and slide it under the press. Finally, they pull down on the press with a force of about 10 lbs.
After the travel team returned from their trip to Rwanda in the summer of 2015, the Tile Press Team began working hard to make a new, innovative design to update the existing molds which shape the tiles. Initial meetings assessed the current mold designs and established the constraints and criteria that we would need to meet, and a design was made. One of the most essential parts of our new design was that each mold was made with interchangeable parts. In order to streamline the tile making process further, the team wanted to have a mold that could be prepared away from the table, brought to the table to be pressed, and then taken away to be removed from the mold. The team built 5 updated molds in the fall of 2015 that will be implemented by the 2016 travel team. JJ Galvin lead the efforts to redesign the Tile Press molds.
The clay mixer is a very simple process. The workers take the clay from the mountainside and put it in the mixer drum, then pedal on a bike which powers the mixer. The mixer is a Bluebird model 12 mixer adapted with a geared pedal system to manually power the device. The engineering work will be designing the mechanism and components to adapt a second-hand mixer to manual power.
The most prominent engineering concern is creating a safety mechanism to protect the user from the moving chain and create a rigid stopping system to make sure the clay mixer blades cannot move when the container is opened. To do this, a steel chain guard will encase the chain so that hands or clothing cannot get caught. A pin will be installed which will be able to fit through the gear teeth and prevent the chain and blades from moving when in the locked position. The mixer will be shipped to Rwanda this summer with the 2016 travel team.
In order to continue EWB-SCU's collaboration with Nyange, the 2015 travel team began to look at a long-term project that would further increase sustainability in the community. They found that PICO's assessment that the community's greatest need is tile and brick output was correct, but the project could be furthered through redesigning the community's kilns. The current kilns are thermally inefficient in that they do not utilize any heat flow or ventilation systems. In addition, they burn eucalyptus, which harms the environment and breaks the deforestation laws of Rwanda.
During the school year, the team that designed the molds for the tile press transitioned into a kiln design team. The new team has Mechanical and Bio Engineers working together to improve Nyange's kilns. This year's work has been to research existing kiln designs, since many already exist which fit most of the constraints. After the team had found a dozen different, already build designs, a matrix was made to decide which kilns would be easiest to adapt to Nyange's terrain. Three designs stood out and will be assessed on-site in the community by the 2016 travel team. Further research in the next few months will be finding a new fuel source and looking at adapting the kiln designs to a new terrain.