Namaste, Sai here. Today was a long and exciting day! Yesterday we talked about how we can change our design to solve the problems we were having. There were a few changes that we all agreed on to do for the second prototype. We decided to increase the overall size of the stove so that there is more room for pots and for the chimney. Since the pot was touching the chimney on our first model, we would move the chimney further back and create a short tunnel from the combustion chamber to the chimney. Another change was to move the opening to the chimney closer to the top stove so that the air will flow up towards the pot before going out of the chimney. We also decided to decrease the diameter to 3 inches to decrease the airflow through the stove. For the opening for the pot, we wanted to design it so that the pot sat lower in the stove but also fit all the different pot sizes. With all of these changes in mind, we were ready to build today.
We built our 2nd prototype today based off the design changes that we had decided on yesterday. When we arrived in Dolutpura, Sumitraben had the mati piled up and was ready to build. We explained to Sumitraben our new design and asked her for suggestions or any concerns that she had. She said that as we build the stove, she will put in her input.
As Shilpen and Kaylla were making the mixture, Erica and I began working with the chimney. The sheet metal that we had got for this chimney was a different material so we decided that it would be better to find a strong pipe that we could roll the chimney around. When we just rolled the chimney, there were some gaps between the rolls because the sheet metal had folds in it. Kaylla and I went to the factory and found a really heavy pipe that was the approximately the diameter that we wanted.
After it was cut to an appropriate height, we took it back to Dolutpura and folded the metal around it. Then we folded the edges together so that there were no gaps. While Shilpen, Erica, and Viral worked on this chimney, Kaylla and I started building the foundation for the stove with Sumitraben. We built a larger foundation so that there would be space between where the pot is placed and where the chimney sits. After we finished the foundation, we asked Sumitraben for her largest and smallest pot so that we can make sure that they sit without any large gaps or unevenly. The chimney was done at this point so we pushed the middle section of the back part down so that we can make the opening for the chimney higher. Also, we made sure to make the opening to the chimney have a sort of funnel shape for better airflow. Furthermore, we packed more of the mixture behind the chimney for support. Finally, we smoothed out the whole stove with some water. While we were building the stove, Sumitraben and Manjulaben were sharing their opinions about the design changes. Sumitraben made some suggestions about the bridge that we were adding to the front of the stove so we are going to look into the change for the next modification.
Tomorrow, we are going to cover the stove with the cow-dung and clay mixture and wait for it to dry! We are excited to test prototype number 2!!