Solenoid valves for a reflux column: water, LM and OLM in automatic distillate take-off

Solenoid valves for a reflux column are three small electrically operated valves: the water valve, the LM valve and the OLM valve. Instead of you turning taps by hand, the EQUINOX-RK.10 column controller opens and closes them, so cooling, distillate take-off and column rinsing follow a program rather than depending on whether you happen to be standing next to the still.

In short

• Three solenoid valves: water (cooling), LM (take-off from the column head pool) and OLM (lowered side take-off).
• The EQUINOX-RK.10 controller opens and closes them automatically at each stage of the process, from heat-up to rinsing the column after the run.
• The controller kit includes solenoid valve cables with plugs fitted; an extra cable costs 25 zł (≈ €6).
• In manual mode you still operate the valves from your phone; you just make the decisions yourself.

What each of the three solenoid valves does on a reflux column

Each valve is responsible for a different flow: the cooling water, the take-off from the column head and the side take-off. These are three different jobs, which is why the controller has three separate outputs and three separate cables for them.

Water valve

The water valve opens and closes the water supply to the cooler. In the EQUINOX-RK.10 automatic cycle, it opens the water circuit after heat-up and rinsing of the pools, and at the end of the process the controller switches off the heating and the cooling. You do not have to remember to turn the tap on, or to turn it off when everything is finished.

LM valve

The LM valve controls the take-off from the column head pool. On Abratek columns the foreshots are also taken off through the LM, while on UFO columns this stage is a pool drain instead.

OLM valve

OLM is the lowered side take-off. This is the valve the controller uses to run the take-off of the hearts with rate correction: when the reflux column temperature calls for slowing down, the valve draws off less, and when the process is stable, it draws off at a steady rate. During the take-off of the hearts it removes the remaining foreshots from the column, which affects the clarity of the final product. The controller rinses the LM and OLM pools at the start of the process and, when it detects the tails, can switch the take-off path.

How the EQUINOX-RK.10 controller operates the solenoid valves step by step

The controller goes through the same stages in every process and opens the valves at precisely defined moments. Here is the automatic cycle of the EQUINOX-RK.10:

1. Heating up the boiler charge.
2. Rinsing the LM and OLM pools.
3. Opening the water valve and automatically reducing the power to the working level.
4. Column stabilisation.
5. Pool drain (UFO) or foreshots take-off through the LM (Abratek).
6. Setting the reference temperature (TEMP DNIA in the app, literally the ‘day temperature’), i.e. the controller’s own reference point for this particular run at today’s pressure.
7. Take-off of the hearts with dynamic rate correction.
8. Notification that the tails have appeared and, if required, switching of the take-off path.
9. Finish: switching off the heating and the cooling, recovery of the remaining distillate and rinsing the column after the run.

The controller does more than open valves. It also looks after safety: it stops and raises an alarm on faulty probe readings and if the condenser overheats. So if the water stops flowing and the condenser temperature crosses the threshold, the process stops instead of carrying on regardless.

We describe a full run from start to finish in our article reflux column automation.

Want the valves to switch by themselves? See the EQUINOX-RK.10 230 V distillation column controller, which handles three solenoid valves, two heating elements and four probes.

Automatic distillate take-off vs manual mode

In manual mode you set the power, take-off rate and valves yourself, but you do it from your phone, not at the tap. The controller shows the temperatures from the four probes (boiler, buffer - the bottom section of the column, 10th plate, condenser), and you decide when to open the LM, when to open the OLM and when to change the power. It is a good mode to start with, while you get to know your column.

In automatic mode the controller runs everything from heat-up to finish, with the same steps every time. The three-phase version and the add-on modules let you choose between stripping and fine rectification. For the valves the difference is simple: in manual mode you are the program, in automatic mode the program is in the controller.

You can see both modes in the app on Android, iOS and Windows, with temperature charts and notifications. Wiring the controller and the first start-up are covered step by step in our guide on how to set up a still controller.

Solenoid valve cables: what is in the kit and what to buy separately

The EQUINOX-RK.10 controller kit includes solenoid valve cables with plugs fitted, so connecting them simply means plugging them into the right sockets on the power module. You do not need to solder or crimp anything.

If you need a longer cable because your water solenoid valve is further away from the controller, or you want a spare, you can buy a solenoid valve cable separately for 25 zł (≈ €6). It comes in two lengths, and other lengths can be ordered.

Solenoid valves themselves are a standard component in many installations: the valve is opened by an electromagnetic coil when voltage is applied and closed by a spring when the voltage is removed. You will find a general description of how they work in the encyclopedia entry on the solenoid valve.

Already have a WiFi thermometer? Add the valves with an add-on module

If you measure temperature with an EQUINOX T-4 thermometer, you do not have to buy a whole new controller. The thermometer add-on module turns it into a column controller: you get a power module with heating element sockets, support for three solenoid valves (water, LM, OLM) and the cables in the kit. The thermometer you already have becomes part of the new set-up and keeps working. You will find the details on the page of the EQUINOX-RK.10 reflux column controller add-on for 230 V, and the whole conversion in our guide to the WiFi thermometer upgrade.

For the record: this article is about equipment and automation, not about making alcohol. Before you use the still, check the regulations in your country. In many countries distillation is regulated.

Frequently asked questions

How many solenoid valves does the EQUINOX-RK.10 controller handle?

Three: the water valve, the LM valve and the OLM valve. Each has its own output on the power module and its own cable with a plug in the kit.

Do I need all three solenoid valves?

The controller is designed for three valves, and the full automatic cycle uses each of them. In manual mode you operate the valves yourself from the app, so you can start with what you have and expand the column later. If you are not sure how this fits your column, email us at [email protected] and we will help.

What happens to the valves when a probe gives a faulty reading?

The controller stops and raises an alarm. The same happens if the condenser overheats. You get a notification on your phone and can see on the chart at what point the process stopped.

Are the solenoid valve cables included in the kit?

Yes, cables with plugs fitted are included with both the controller and the add-on module. An extra or longer solenoid valve cable costs 25 zł (≈ €6), and we make other lengths to order.

Summary

The three solenoid valves (water, LM and OLM) are the controller’s hands: without them the program can only watch the temperatures; with them it can act. The EQUINOX-RK.10 opens them at each stage, keeps an eye on the condenser and the probes, and at the end recovers the remaining distillate and rinses the column. The cables with plugs come in the kit, and you can buy a spare one for 25 zł (≈ €6). We are a Polish manufacturer, and if you need help connecting it, email us at [email protected].

See the EQUINOX-RK.10 column controller in our shop and stop turning taps by hand.