Wash column (BK)

A wash column (BK) is a reflux column fitted with a flow-through dephlegmator and a short column section with coarse or very sparse packing. It has proven itself for producing a purified distillate that keeps the taste and aroma of the original raw material.

The product is taken off "as vapor after the dephlegmator". Controlling the column comes down to two parameters: heating power and dephlegmator cooling. The take-off rate is regulated by the speed of the cooling pump.

Samovar 7.00: BK mode now has a take-off program. It defines up to what boiler temperature (or ABV) to continue the take-off, into which container, at what voltage, and what vapor temperature to hold. Samovar holds the vapor temperature by itself, changing the water supply to the dephlegmator. Lines with a vapor temperature of 0 leave the cooling under manual control, as in older versions.

Main window of the operating mode

Main window of the Wash column (BK) mode

Cooling pump

The slider adjusts the coolant flow rate.

The power is changed by PWM modulation.

You can control it either with the slider on the speed scale or by entering values directly in the field.
The leftmost slider position is the minimum pump speed (PWM_LOW_VALUE, 100 units by default).
If the slider is in the rightmost position, 12 volts are applied to the pump without modulation. The input field value =1023.

So, as a rough estimate for simplicity, 10 units = 1% of power. Any manual change turns off the automatic vapor temperature control until the end of the line.

Auto («Автомат»)

Returns the cooling to Samovar control based on the vapor temperature from the current program line. The button is visible only when the heating is on and the line has a vapor temperature set.

Boiling confirmation

Which sensor Samovar used to confirm that the boiler is boiling: vapor and column section is an accurate sign; boiler, water or their combination is less accurate. Before boiling - "waiting for confirmation" («ожидание подтверждения»).

Regulator

Voltage regulator control. See Manual voltage setting of the regulator.

Turn heating on

Starts and stops the column. When the heating is on, the button is called "Turn heating off" («Выключить нагрев»).

The remaining data is the same as in the main window of the "Rectification" («Ректификация») mode

Start and boost

Before starting, assign the boiler sensor: without it Samovar refuses to start with the message "BK not started: boiler sensor not assigned or not responding" («БК не запущена: датчик куба не назначен или не отвечает»). If the program has lines with a vapor temperature above 0, a vapor sensor is also required ("BK not started: program requires a vapor sensor" («БК не запущена: программа требует датчик пара»)).

After the heating is switched on, Samovar shows the message "Wash column heating on" («Включен нагрев бражной колонны») and sends the "Boost" («Разгон») command to the regulator.
When the boiler temperature reaches 77°C
in the file Samovar_ini.h the line:

#define OPEN_VALVE_TANK_TEMP 77 //Boiler sensor temperature at which the water supply valve opens
Samovar opens the water supply valve and switches on the cooling pump at the speed set by the "Pump speed" («Скорость насоса») slider. The minimum pump speed is set by the line

//Lower value (in percent) for the PWM regulator of the pump. Choose a value that ensures water flow

#define PWM_LOW_VALUE 10

Attention.

It is recommended to set maximum cooling right away.

The boost continues until Samovar confirms that the boiler is boiling. Signs of boiling: the vapor or column section temperature is above 39°C, or the boiler temperature stops rising while the water temperature keeps rising. The sensor that confirmed boiling is shown in the "Boiling confirmation" («Подтверждение кипения») line in the main window.

After the boiler starts boiling, Samovar sets the configured BK working power. The default value is 45 V for a voltage regulator or 200 W for SEM_AVR. You can change it in the "BK power after boiling" («Мощность БК после закипания») field on the settings page. If the first program line specifies a voltage, it is applied on top of the working power (as an increment if it is less than 40 V / 400 W, otherwise as an absolute value). Then Samovar proceeds to the first program line.

Program

The "Program" («Программа») tab of the Wash column (BK) mode

Program type

The condition for moving to the next line: boiler temperature (T), ABV in the boiler or in the take-off, absolute or relative (A, S, P, R). The types are described on the page Distillation program.

Voltage

Regulator voltage (power), applied when the line condition is met. 0 - do not change. For the first line it is applied right after boiling starts, on top of the BK working power.

Vapor T, °C

The vapor temperature that Samovar holds on this line by supplying water to the dephlegmator: 0 - water is controlled manually, 30..100 - automatically. Other values are not accepted ("Program error: Vapor T: 0 or 30..100" («Ошибка программы: Т пара: 0 или 30..100»)).

Program line: Type;Value;Container;Voltage;Vapor T. The first four fields and the line types T, S, A, P, R, L (Lua stage: the .lua file, the timeout in seconds and the parameters are set in the "Lua stage" («Lua-этап») window) are the same as in the distillation program: when the line condition is met, the servo moves to the specified container, the regulator receives the specified voltage, and Samovar moves on to the next line. The fifth field is the vapor temperature to hold on this line: 0 - water is controlled manually, 30..100 - Samovar selects the water supply to the dephlegmator by itself.

Example program:

T;78;1;190;70

T;90;2;0;78

T;93;2;0;0

After boiling starts, Samovar holds a vapor temperature of 70°C (heads take-off). When the boiler heats up to 78°C, the servo moves to container No. 1, the regulator gets 190 V, and the vapor setpoint becomes 78°C. At 90°C in the boiler - container No. 2, the voltage does not change, and the cooling goes to manual control. At 93°C in the boiler the lines end, and the take-off continues until the end condition.

If the program has no lines, after boiling starts Samovar works as before: the operator controls the power and cooling manually.

Dephlegmator cooling

With automatic cooling, once a minute Samovar compares the vapor temperature with the line setpoint. If the vapor is warmer than the setpoint by more than 0.2°C, the water supply is increased by one step (30 PWM units out of 1023); if it is colder, the supply is decreased, but not below the pump minimum and not when the water is already hotter than 65°C. The state is shown by the label "Water: auto 78.0 °C" («Вода: авто 78,0 °C») or "Water: manual" («Вода: вручную»).

Any movement of the "Pump speed" («Скорость насоса») slider (or entering a value in the field next to it) turns the automation off until the end of the line, and Samovar reports "Dephlegmator water: manual control" («Вода дефлегматора: ручное управление»). You can turn the automation back on with the "Auto" («Автомат») button; it is visible only when the current line has a vapor temperature set.

Following the process sheet of the upcoming run, the operator sets the required heating power and, gradually reducing the cooling supply, achieves drops from the take-off spout of the condenser.
- The heads take-off has started.
Then, during the hearts take-off, the required take-off rate is likewise achieved by adjusting the heating and cooling.

Samovar does not take atmospheric pressure into account in this mode.

Completion and safety

The safety system is active.

If vapor breaks through and the TCA sensor is connected through the control unit to the take-off spout, the heating is switched off.
When the water temperature approaches the critical value, Samovar sounds a beep, shows "Critical water temperature!" («Критическая температура воды!») and reduces the regulator voltage by 5 units.

Samovar switches off the heating with the message "Wash column run finished" («Работа бражной колонны завершена») on any of these conditions:
- the set boiler temperature is reached;
- there is no alcohol left in the boiler: the boiler temperature is above 90°C and does not rise by 0.1° during the time from the "Time for distillation completion check" («Время для контроля завершения процесса дистилляции») field (0 - the check is off).

After the heating is switched off, the water is shut off in the same way as in distillation mode: when the water temperature drops 20° below the setpoint, or when the boiler cools down.

A log is kept and charts are plotted.