Friday afternoon after a full week in Malang (6/4/2021)

It has been a full week. Language learning every morning, project work and/or training sessions every afternoon, and prep for training sessions and/or conversations with my host family every night. This post will focus on the engineering projects for the trip. For the techy folks, I hope this post will be helpful. For the non-techy folks, sorry, I hope this post won't be too boring (take a look at the pictures at least). The two projects I am working on are microwave vacuum dehydration and cold storage. I think I have a good grasp on the background and deliverables for each project. 

For the microwave vacuum dehydration project, the problem we need to solve is holding a vacuum while simultaneously rotating the turntable tray. It is fairly well researched that for microwave dehydration, a vacuum is extremely helpful to lower the boiling point of water, thus preserving the quality of the dehydrated fruit. It is also fairly well researched that to energize something using microwaves, rotating the turntable tray is extremely helpful to provide even heating. But could both of those problems be solved simultaneously? We think so. Our first design (which wasn't even our idea) is to use a 4 bar linkage and the existing turntable motor to provide ~150° of back-and-forth motion. The vacuum chamber will be paired with flexible hose to make twisting possible. The picture below shows the 3D printed parts that comprise the mechanical linkage. In the picture we are also making a mark for the approximate new position of the turntable motor. At this point, everything is approximate and a bit janky; our goal is to get something working. I'll try to add a short video to a future blog post when/if we get something working. 

For the cold storage project, the task is to redesign the system for flash freezing and cold storing mangoes. The project is more in the realm of industrial engineering than mechanical engineering, but we are nonetheless moving forward and excited. The process isn't overly complex. The mangoes are peeled, sliced, and placed onto trays. They are then inserted into an industrial flash freezer to ensure that they freeze as fast as possible (there is science about why that is important but I won't go into it here). After that they are scraped off the trays, bagged, and vacuum sealed. Finally, they are placed into the freezer for long term storage. The goal of this process is to extend the 2 month mango season; if there are mangoes in cold storage when it is not mango season, then workers can still work during those months to dehydrate the fruit. The overall goal is more consistent work throughout the entire year. So far, my part of the project has consisted of reading a bunch of user manuals (I included a picture of them because there really isn't anything else to take a picture of right now) for the different machines and creating documents about maintenance and standard operation, as well as brainstorming revisions to the SOP (standard operating procedures). Fun stuff.