Reflux Method: Assembly and Use
The Reflux Mode is used for the highest degree of purifications is generally selected for the distillation of vodka, neutral spirits, and water, where extremely high purity is desired.
When distilling in reflux mode, it is extremely advantageous to have a longer column than in traditional distillation. In addition, filling is added to the column for the refluxing liquid to flow down through, aiding in increased purity. There are many forms of column packing available, varying in surface area and
material. It is important to use a column filling with a large surface area : volume ratio, such as small size Raschig Rings(6mm x 6mm), or metal mesh.
If using the still unit,attach the column extension to the still head before proceeding.
To assemble your unit for use in the Reflux Mode, attach the 8' tube with the female hose fitting onto inlet 'A'. Attach one 18 hose to both B and C,
and the other 18 hose to D and E. Place the other 8' piece of tubing onto outlet 'F'. The 4' tube will connect to the bottom of the condenser G,
and run into your collection container. Moisten the thermometer, slide it into the hole of the rubber stopper and place the stopper securely in the top of
the column. Try to have the bulb of the thermometer just above the condenser.
For Ceramic Raschig Ring Users - Clean the ceramic Raschig Rings by rinsing thoroughly with hot water. Lean the column slightly to the side and pour the Raschig Rings in slowly to avoid damaging the stainless steel screen at the bottom. Raschig Rings can remain in the column except for occasional cleaning. After each use, back flush with boiling water. After every second
to third use, it is recommended that you remove the rings from your column and clean them in a Glasrens solution, then rinse well with clean water.
For Copper Mesh Users - Roll the Copper Mesh into plugs’ that fit snug inside the distillation column. The copper mesh plug should be snug enough to stay in place (i.e. Not slide out of the column), while not being
compressed by the column, thus restricting flow. It is best to roll the mesh loosely to somewhat snug, but it is not advised that you roll the mesh tightly, as this will restrict vapor flow. Usually a 3½ to 4 foot long piece of mesh is sufficient for one ‘plug’. It is also beneficial to cut a few smaller pieces from the remaining mesh to tuck in the area of the cooling lines. Due to the nature of copper, it is advised that you remove the mesh from your column after each use and allow to dry completely in order to avoid tarnishing. It is also suggested after every second to third use that you clean the copper with
vinegar or another food grade copper cleaner, rinse well, and allow to dry completely.
When using the reflux method, most of the water will be left behind in your kettle, so it is generally not a concern that you will boil your kettle dry (please note that this is not the case when distilling water with your Essential
still unit). This is because you have effectively separated all of the constituents and collected only those with a boiling point equal to and lower than the temperature at the top of your column. If you start with 25qt. Of liquid in your kettle, and collect 5qt. Of product in your collection container, you will have 20qt. Remaining in your kettle / column.
Syphon or pour the liquid that you intend to distill into the kettle. Do not fill the kettle above 24qt. (23L). This allows room for the liquid to expand as it heats up without being forced up into the column. Some items will foam more when boiling, making it necessary to not exceed 18-20qt. In order to allow the additional void space required, or to add an anti-foam agent to reduce
Attach your column and place the unit on your heat source. In order for your column to reach equilibrium, which is imperative for proper reflux use, it is important to use a constant heat source. Use of a cycling heat source will dramatically reduce the stability within your column and reduce the purity of your distillate, as well as make it more difficult and frustrating to control the
temperature at the top of the column. With a constant heat source you should find that equilibrium is reached, and the temperature at the top of the column will remain extremely consistent.
Once the liquid in the kettle has begun to boil the heat will rise in the column rather quickly. During this time the steam is also raising the temperature of the column filling material. When the temperature starts to rise in the column it is time to start the flow of cool water through your column cooling tubes and condenser. Start with the water running slowly. This will be adjusted once the vapor has made its way to the top of the column.
Once vapor has made its way to the top of your column you will see the temperature rise rapidly, as recorded by your thermometer. At this point you will notice liquid will start to be expelled from your condenser. You must
pay attention to the temperature recorded on your thermometer, as this is how you know what constituents are being removed.
All constituents with a lower boiling point than your desired product will be expelled first. You will notice that the temperature at this point will be lower than the temperature of your desired product. As the temperature nears the boiling point of your desired product you will be exhausting all of the lower boiling point constituents. Allow your temperature to stabilize at the temperature of your desired product. Once temperature has stabilized, you should start to collect your distillate in a new container, and discard the previously collected distillate.
Your temperature should remain constant for the duration of your distillation. If necessary, adjust the flow of cooling water to both maintain this temperature
and ensure that the distillate being drawn from your condenser is cool to slightly warm. If the distillate is hot you should increase the flow of your cooling water to ensure that it is properly condensed.
Continue to collect your distillate until the temperature at the top of your column rises. When the temperature at the top of your column rises you have distilled all of the component that you desired, and should shut the system
down. Depending on the product that you are distilling, you may be removing most of the product from the kettle (such as water distillation). If this is the case you should shut the system down after collecting all but 5qt. Of liquid. This ensures that you do not boil the kettle dry.
To shut the system down, remove it from your heat source (follow Cool Down procedure to avoid damage to your unit). Once your unit has cooled, remove the column from your kettle and back-flush with hot water to clean the column filling material. Empty the remaining liquid from the kettle and rinse thoroughly with warm water. It is suggested to clean your kettle with warm soapy water or a Glasrens solution, and then rinse well.