It is not recommended to connect the pump directly to a pressurized water line. It is highly desirable to install an intermediate tank with a float valve.
A float valve is simple and reliable. It works for years without problems. To guard against leaks, you can add an emergency overflow line.
Diaphragm pumps are mostly self-priming, but it is still better to take water from the bottom of the tank, through a fitting, so that the pump is always supplied with water.
Recommended pump: 12 V supply, up to 60 W, flow rate 2-3.5 L/min.
Note
During rectification on a 2" column, water consumption is about 40-50 L/h. During distillation with a 3 kW heating element, consumption is higher.
These are the pumps most commonly used.
Although its power is excessive, such models have proven themselves well. Note the screw and the cover on the left. This is a device that automatically cuts off the power when the pressure is exceeded. It may be adjustable or not. Some models may not have it.
If you plan to use such a pump, the 12 V power supply of the Samovar must be suitable, for example 12 V 100 W.
The pump is noisy, keep that in mind when choosing where to place it. *
If you plan to use the pump only for rectification, a more modest pump will do. Its small size lets you mount it directly on the tank or on the column. The noise from such a pump is also lower.
Operating voltage: 12 V DC,
Operating current: 0.5-0.7 A (power must be more than 6 W)
Flow rate: 1.5-2 L/min (or thereabouts),
Maximum suction lift: 78.7 inches (2 m)
In principle, you can use any 12 V diaphragm pump whose specifications suit you.
* There is a way to reduce the noise and make the pump more comfortable to live with: change the PWM frequency. By default it is set in the file pumppwm.h; to avoid editing that file, add your own line to user_config_override.h:
#define PUMP_PWM_FREQ 15
15 is the default PWM frequency of the cooling pump, in hertz. You can set up to 450. This parameter is not available in the configurator.
You also need to add a flyback diode across the inductive load. It sounds scary, but it is simple: install a diode as close to the motor as possible.
Any diode will do, rated for a current not less than the motor current. Fast Schottky diodes have proven themselves well, for example 1N5844 or similar.
A little more detail - post in the thread
