and here is how I built her...
starting in the foreground the 25m coil of 8mm copper (microbore) pipe. Trying to divide the pipe into eight pieces was tricky to do, but once marked out it was cut using the pipe slicer you can just about see.
Going back slightly you can see one cut length.
Behind that the pipe has been tightened around my 3-gal cornie.
Even futher back you can see the pipe has been tightened even more around the small CO2 cylinder, before finally having the in and out bent at 90 degrees upwards using a pipe bending tool (bought on offer from BnQ just for the job!)
The first four coils made (lower section) - just four more to make for the upper section
Again the 4 lower coils and the 4 upper coils mid process of being made.
Both upper and lower coils (all 8 made).
and a rough approximation of how they will stack on top of each other. The maximum diameter is designed to fit in my 75 or 100 litre steel pot.
Here I am making the fig-8 copper connectors that will hold various pieces together. They are made out of 22mm pipe sliced into thin tubes, then hammered into shape around two drill bits.
cleaning the fig-8 connectors using distilled vinegar that has been boiled.
The result are shiney copper connectors
So here I got bored of taking photos but the last bit was the most laborious and tedious. This involved threading lots of stainless steel washers onto each of the coils to space them apart to improve thermal conductance (surface area). I also soldered on the two, 4 x 8mm to 1 x 22mm brass manifolds, and the rest of the 22mm copper pipe work and then service valves connected to hoze lock fittings to make connection a breeze to the hozepipe.
I was really chuffed when doing a test leak as at full pressure there was no leaks - thank god!
Finally the coils where held together with twists of copper wire taken from twin and earth wiring stripped of its insulation.
The result is an 8 coil immersion cooler.
My thinking behind my design is that previously I did a twin concentric design which was pretty efficient....
When I though about the design I realised that as the cool water travels around the coil eventually it will reach the same temperature as the wort. Now with thin copper pipe I reckon this happens within a meter, so the other X meters of pipe (probably between 4 to 9 for most people) no heat exchance is taking place. So with my design the water is split 8 ways. The wort is still in contact with 25 meters distance of pipe, but the cold water flows only around 3 meter individual coils.
The result is looking good so far. For 70 litres of boiling wort it took 1 hour to drop to 22'C pitching temperature.
Ben
......I want to chill some wort....make a choice... cool or die!!
