On Triangles, Geodesics and our spirit still.

The keen eyed will have noticed our spirit still doesn't look like many others of its ilk.  The neck, Lyne arm and condensers are all familiar but the shoulders are like something from a Jules Verne novel. The history of how we came about this design is the topic of another post, but the why we did is what i'll explain here. 

The sphere has the smallest surface area to volume ratio of any solid. Stills are traditionally oblate spheres or some version of them. We argued that what we wanted was copper contact and the largest surface area to volume ratio we could get. 

As you can see from the chart above, a pyramid has the largest surface area as the volume increases, and introducing flat planes into the face of the solid pushes the shape up the curve. 

Our original spirit still was completely geodesic in shape, however for the new still we have tailored the shape to increase the vertical flat surface are to more approximate a icosahedron or cube.  We still need reflux and the vapour to flow cleanly up the sides of the still so the shape became double triangular faceted. 

Explaining the concept to Garry and Derek of Speyside Copper Works was easy and to their credit, they took on the project with good humour and enthusiasm. After Garrys initial CAD designs, the actual practical mechanics of how to make the shape was the next challenge. 

A pleated folded design was proposed as shown in the test model above.  This required less welding and retained structural integrity but gave us the flat panels were looking for. 

Now the engineering problem of scaling this into 5mm thick copper began. Derek Brewster is a genius in copper [ and apparently with steam engines too ] and seeing the design come to life from the other side of the world was very exciting. 

 

We are thrilled with the result and the excellent work from Speyside Copper Works, thanks to Garry and Derek.