Designed to operate as a pot still when the packing is removed from the column, valved reflux still, unlike internal reflux still, is not equipped
with cooling tubes and you can adjust the reflux flow can to suit the task by a simple valve adjustment. Operating valved reflux still is much easier because the valve on still head provides you with a direct control of distillation and the reflux rate. You can navigate through further topics by visiting www.stilltutorial.com.
As we did with the internal reflux still, we will start off by testing this homemade still using water. To do this, fill the boiler with a gallon or two of water. When done, you now need to install down the top end with the aid of keg clamp screws. Shut each needle valve on the still head and set up the cooling hoses. Now install a thermometer in the column cap.
With the apparatus now set up, turn on the heat to a high setting in order to bring the water to boiling, the same way you did with the internal reflux still and following this, turn on the water circulation. Just as the temperature rise up to 100° C, the boiling point of our liquid, you will notice steam rising up at the still head. At this moment, turn down the heat until the steam is no longer able to escape. However, make sure that you do not turn down the heat so much that it causes the temperature to fall below the boiling point, which, in this case is 100° C.
At this point, the water will still be boiling; however, the vapors are now being condensed in the coil in the still head. The condensed vapor will run down the still head and would be collected in the valved cap and would nipple at the bottom of the assembly. Next, open the collection valve which will allow you to measure the maximum distillation rate without any reflux. Just as with the internal reflux still, measure the time it takes for 250 ml of water to collect.
Since the maximum distillation rate has been determined, now, close the output valve and open the reflux valve. This will allow the system to operate in total reflux. When the system has operated in full reflux for a few minutes, adjust the output valve such that the collection rate is of about 1/3 of the maximum rate. This means that about 2/3 of the distillate will flow back into the column for re-distillation while the remaining 1/3 will be collected as output. At this point, you might also want to experiment a bit with the reflux valve to increase or decrease the amount of distillate returned to the column or retained in the holding cap.
When you have become comfortable with the operating controls, it is now time for you to shut down and clean up the apparatus. Unlike the internal reflux still, the valved reflux still can be shut down in any order where a specific one is not present. The reason behind this advantage is that there is no danger of implosion as the column is always vented to air at the top of the column head. In spite of that, it is recommended that you first remove the column cap and the thermometer. Use gloves to avoid any injury as the column cap might be hot. This step would eradicate any chance of breaking the thermometer while removing the column from the boiler. You need to be very careful when dealing with the almost-boiling water which is remaining in the boiler and when disconnecting the heat supply, both, electric and gas. Once you have disconnected the water hoses, you may remove the top end from the boiler in order to clean up the apparatus.
Although easy to operate than the internal reflux still, make sure that you operate this homemade still in a manner which causes no harm to you. For more safety measures, visit: http://www.che.ufl.edu/ren/course/4404L/CD/CD.pdf.
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