Technology By Clara Lu — Date 08.9.2016

“We built a machine that will give people both pure and healthy water.”

Mitte's mechanical design engineer Moritz König on his experience and inspiration for developing Mitte.

It’s always inspiring to come out of a conversation feeling that you just learned about something new and meaningful. This week I sat down with Moritz König, one of the engineers at Mitte and talked to him about the engineering process. During our conversation he offered some interesting insight about the concept, functionality, and development of the appliance.

Moritz is the mechanical design engineer at Mitte and a true Berliner. He became interested in rapid prototyping and thermal engineering while studying in university and worked as CTO for the startup ecoglobe for two years, before he met Faebian Bastiman and Moritz Waldstein. Through his own travels he was alarmed at the masses of plastic bottles piling up in Northern Africa and the Pacific Region. Thus the outlook of working for a venture that can help eliminate plastic bottles intrigued him and you can tell from his enthusiasm that he is sincerely engaged in this project.

At Mitte he is in charge of research and development of the core technology.

Tell me how you approached the engineering process. What were the key goals?

Our objective from the beginning was to build a machine that will produce both pure and healthy water. At the same time, this machine should be as environmentally friendly and efficient as possible. These goals are the guidelines in the whole development process.

Your job obviously includes a lot of research. Can you outline the differences of customary filter and purification processes?

If you want to make really pure water, there is only one option that is distillation. This is common sense in all medical applications. It is also how nature’s water cycle has successfully operated since the formation of earth.

Please don’t get me wrong: Filter processes work well for multiple water-related applications like reverse osmosis. But in terms of purity and reducing waste they are simply not the first choice, as they do not fully remove hormones, micro plastics and germs.

The investment costs are lower with most filter devices, but they are never fail-proof. If, for example, if a membrane is damaged, the consumer has no way of knowing about that although the water quality of the output may be impaired. Our machine on the other hand constantly monitors the quality of the water that it produces. If one part breaks, there wouldn’t be any water output at all.

You are constantly measuring water samples and comparing your findings. What exactly are you measuring and how?

For every step in the development we have to be certain that it will improve the product. Verifying this is quite complicated. Therefore we use a complex measuring set-up.

We measure the water that goes in the machine, what happens with it inside the machine, and the quality of the output. The factors we measure are total dissolved solids (TDS), meaning the total amount of mobile charged ions—meaning minerals, salts, or metals—that are dissolved in a given volume of water; pathogens, micro plastics, and energy consumption. Inside the machine we monitor water temperatures, pressure, and flow.


Compact set-up for measuring TDS


Visualization of various measurings from inside the machine

What are some significant accomplishments so far?

One turning point in our developing process was the invention of our current peltier-powered distillation process. We tried to shrink a common distillation approach called multi-stage flash, which turned out to be virtually impossible and felt totally stuck. Peltier elements are semiconductors that are cool one one side and warm on the other. Due to their cooling qualities, they are commonly used for ice boxes. However, they are known for not having the most favorable energy efficiency ratings. In our implementation, we are making use of both features, heating and cooling. We do not waste half of the energy, which is usually the case, and created a meaningful and efficient application for these components.

So far we successfully built and tested most of the components that our dream machine will be made of in several prototypes.

We have already managed to generate water quality that is very pure. The real challenge now is to make it affordable to the masses.




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