home still: complete assembly, cooler, and temperature control

I haven't posted anything about the still in a while, but the work has been steady. In fact, the construction is complete.

Completed Assembly.

With some preliminary testing with water, I realized that there was a slight flaw with the condenser design. It condenses the vapors well, but since the condensed drops just fall off the coil, the liquid is still very hot. I decided to add a cooler in order to bring the temperature down.

The cooler is the smaller tubes in the foreground.

The cooler is a simple tube and shell cooler. The cooling water is plumbed from the outlet of the condenser so that I can operate both with a single pump. With this configuration I'm able to get the condensate to almost room temperature.

Another component completed is the temperature control for the pot heater.

Temperature control unit.

The control unit is the same as some DIY Sous Vide controllers that utilize a PID heater controller and solid state relay. The control unit powers a water heater element which is connected to the pot with a sanitary fitting.

Heater element with detachable cord.

I did notice some inconsistencies in the temperature readings as compared to other thermometers, but this heater unit can hold consistent temps. I believe this may be due to a slow reaction time of the RTD probe.

Other experiments have also shown that it will be better to use the dephlegmator to control vapor temperature, so I may use the temperature controller to power the dephlegmator pump instead.

The experiments will just continue from here...

home still: column, dephlegmator

Completed dephlegmator and column.

Today I completed the assembly of the column and dephlemator. The column design is very similar to the gin basket, but with the addition of a thermo port on top.

Thermo port tube.

The thermo port is just a tube with an opening cut into it. The opening allows the probe to be in the vapor stream, but prevents condensation from dripping onto it and changing the readings. A silicone plug with a thermocouple will seal the tube and measure the vapor temperature.

All the main parts were brazed together and ports for the cooling shell were added. The ports are 1/2" OD tubing and I will use push-to-connect fittings to attach them to tubes.

Hand bent cooling coil.

I also started on the condenser portion of the still. The cooling coil was bent with a 90 degree hand-held tube bender from 3/8" OD tubing. I then annealed the copper and squeezed the coils closer together by hand.

The ends of the coil use 90 degree braze on fittings and a straight tube to connect to a water supply.

The next step for the condenser will involve the collection plates and tube for the condensed liquids.

home still: dephlegmator update

Here is an update on some work I have been doing for the still. I have mainly been working on the dephelgmator section.

Internal shell parts.

The plates were all waterjet-cut with the holes slightly smaller and finished with a uni-bit drill. The diverter plates are the semi-circular plates in the picture.

Dry fitted together.

I dry fitted them first to figure out the best way to braze them together. I decided it was best to braze the center tube to the diverter plates first.

Center tube brazed to the internal diverter plates.

I used two other tubes to help align the plates. I like the colors that came out when the copper was heated. It's too bad they will be hidden.

Completed internals.

Some of the plates weren't perfectly aligned and some of the plates bent when inserting the outer tubes. I was able to make it work, but it was not visually appealing.

Major components of the dephlegmator.

I decided to bead blast the interior to remove the oxidation from the inside.

Next will be the final assembly.