My Favorite Patent-And Why

Last year, I successfully introduced the first heat pump distillation system that truly integrates heat transfer in a way that’s practical and highly efficient.

Distillation is a very energy-intensive process, and for many years, people have imagined recycling the heat generated during condensation and reusing it in the evaporation process, but with no success. There are large-scale methods that exist — like multi-stage flash distillation or mechanical vapor recompression — and they work, but each of these processes has drawbacks. 

Multi-stage flash requires VERY large installations to be effective. And mechanical vapor compression, flows the process gas through a compressor, severely limiting what can be processed, adding potential contamination, and adding cost. On the other hand, heat pump-driven distillation allows efficient heat recovery at any scale, from bench top all the way to a large refinery while keeping the process separate from the compressor, increasing process flexibility and purity.

My goal was to create a true turnkey falling film evaporator. When designing a new technology, it is best to start from first principles. To make this project a success, these are the principles I followed 

First Principle:

Minimize the number of heat exchangers because for each additional heat exchanger that we added, it would cause an additional temperature drop. These temperature drops don’t just disappear. The compressor has to make up for these temperature drops which means the compressor has to put in extra work.

Second Principle:

The vapor that condenses into liquids at the bottom of the heat exchanger needs to be drained so it doesn’t build up.  

Third Principle:

Heat exchangers are most efficient in counterflow.

When the hot liquid and the cold liquid flow in opposite directions, maximizes temperature differential across the length of the heat exchanger, making this process more efficient. (See the diagram below) 

Now that I had the three main principles mapped out I needed to put them into practice.

I started with the first principle and the process evaporator. In order to minimize the number of heat exchangers, the refrigerant should exchange heat directly with the process (no oil or water loop to carry the heat), therefore the hot gas from the compressor was piped directly to the process evaporator. That hot gas gives up most of its heat by condensing to a liquid. 

Now, principle two, the condensed liquid falls down under gravity and must drain from the bottom. So the refrigerant should flow into the top to condense and out through the bottom.

Applying principle three. The process should flow counter to the heat source flowing up from the bottom and out through the top therefore, creating a rising film evaporator. 

Putting these principles into practice inevitably led to our patented design and it turned out to work very well in practice.

Even with that solution, there were still a lot of smaller details we had to work through to make the system truly turnkey. Some of which will remain trade secrets. But one challenge was to make sure the system stayed stable, with no runaway heat or runaway chilling as operating conditions changed, leading us to fully automate the controls and create the most automated system in the industry.

All of these small but important details are why it was so critical for us to create a one-button system. Trying to manually control a process like this would be a nightmare. Today, it’s a true one-button startup system that does all the work for you.

The amount of time and effort that went into developing this technology is why I consider this patent to be one of my favorites. It took years of work and testing to get everything right, but the result is a system that works as seamlessly as it does today.

Check out the full patent here: https://patents.google.com/patent/US12042751B2/en?inventor=Agustus+Berman+Shelander