Winding a Coil Condenser
How to wind a small copper coil condenser, by hand, without filling.
Version 1.0, March 2010
This particular condenser in this tutorial is a 150 mm (6") long continuous double coil, for a 50 mm (2") diameter column, and uses 6.4 mm (1/4") copper tube. This size double coil condenser comfortably handles 2400 w of water steam. (Put some mesh or scrubber packing in the top section.)
You can increase the condenser length up to 200 mm without any problem. But longer than that and you start running into increasing back pressure, and hence a reduced maximum coolant flow rate.
You can also increase the coil diameter (width). I would not go bigger than to suit a 75-80 mm column. Larger diameter coils are much easier to wind than smaller diameter.
This tutorial only describes how to do a continuous double coil, but it is the same basic skills and techniques for a single coil, and a single coil is much easier.
Double (and single) coils can also be made using 4.75 mm (3/16") OD tube. This size tube is both easier to work and more efficient at heat exchange, though it is less robust than larger size tube, and might not be as easy to locate either.
Single coils can also be made using 9.5 mm (3/8") tube. It is hard to wind 9.5 mm tube smaller than about 32 mm (1.5") OD, which equals a mandrel of about 25 mm (1"). Winding continuous double coils in 9.5 mm by hand is more difficult, even larger ones for a 75 mm column. The changeover from the inner to the outer coil is particularly tricky.
6.4 mm tube is a very good size for our purposes.
Winding a coil, especially a double continuous coil like this, is not easy. You are likely to make mistakes the first time you do it, especially forming the first turn of the coil.
Read through the whole tutorial carefully before starting. It will help you understand the reason for some of the steps earlier in the process.
The pics were taken during 3-4...