In this article, we will be focusing on the valved reflux still. Unlike the internal reflux still, this model does not work on the internal reflux and neither does it employ a cooling flow for its working. To replace that, it uses a condenser along with a reflux holding container which is mounted in the still head. Furthermore, you will find two needle valves at the bottom of the reflux holding container. The purpose of these needle valves is to allow the regulation of the reflux flow back into the column, as well as the flow to the output collection vessel which is where your product is collected. With a surfaced overview of how the still works, let’s get underground into the details.
Condensation is one of the two basic principles involved in the process of distillation. In homemade stills like these, the evaporated vapor is condensed using a condenser. The condenser for this particular model is embedded in the still head assembly which is further mounted on a collecting outlet which leads to the reflux column. From the column, the vapors are directed through connected tee fittings to the still head. Since the vapors are hot, thereby, they rise through a condensing coil which is fitted inside a 3” tubing shell. It is in this condensing coil that the vapors are condensed. After that, the condensed liquid streams down the still head shell, enriched as it passes the rising vapors, and is finally collected in the valved cap located at the bottom of the Still head. Here, the two needle valves control the reflux and the output flow. For more information about distillation, you can visit: http://www.wiredchemist.com/chemistry/instructional/laboratory-tutorials/distillation.
In the internal reflux still, the condenser was a little complex, being a jacketed flow condenser. The condenser in Valved Still is much simpler and thus, and would of course make it a tad easier to manufacture this part of the homemade still.
To start with, the entire structure is made out of only three soldering fittings. The core of the condenser is composed out of a small coil, looped about ten times, of ¼” soft copper tubing. Following this, the core is further fitted inside a 6” section of 3” copper tubing. It is easy enough to form the tubing around a 2” tubing or some other pipe. Note that kinks and twists may spoil the condenser assembly here. To avoid such twists, it is recommended, that you use a flexible wiring tube bender sleeve.
Once you are done with composing the condenser coil, it is now time to fit it into the casing. This part of the assembly, though not at all esoteric, may encounter you with some difficulty. The difficulty arises due to the fact that the ends of the coil run parallel to the inside of the casing wall and will resist when you try to pass through the hole which is drilled on the center of the casing. To fix and get through with this problem, here is the solution. What you do is that you terminate the coil when it is on its last loop using a 90° compression fitting elbow. This step will permit you to run a short piece of straight tubing from the outside of the shell into the compression elbow which is located inside the casing. After that, you can complete the outside connection by making use of another 90° elbow to fit the water inlet and the outlet tubing.
As you read about the needle valves in the introductory paragraph, let’s go back to them. There are two needle valve controls, located at the lower end of the still head. Both these needle valves are fitted in a 2” cap. The condensate from the overhead condenser collects in this cap and its collecting nipple, while the still is operating. The needle valves then, as it is their purpose, regulate the amount of distillate which is to be refluxed and the amount which is to be collected as the output.
With this, you now have the complete knowledge about the Valved Reflux Still. Good luck for your adventure on homemade stills! For more information, you can visit www.stilltutorial.com.
Note: Remember, the distillation of ethyl-alcohols is illegal without a permit per federal moonshine laws and is inherently dangerous because of ethanol’s flammability (never operate a homemade still indoors). For more moonshine laws and other moonshine still permit information, visit: http://www.ttb.gov/spirits/faq.shtml. Sorry, ya even need a license for personal use due to TTB federal distillation moonshine laws.
For more info on your own homemade copper still plans for home, see http://stilltutorial.com
A Boka still or Bokabob still, is a valved still with a reflux control that uses the same column as the reflux column. See the new moonshine still section and also the kit area to build your own copper still.