How do venturi water jet eductors work?

Venturis eductors work on the principle of differential pressure.
In short, water flows into the venturi at a higher pressure than that at which it exits. This pressure difference creates a vacuum at the suction port on the side of the device. This sucks air, ozone, or liquid into the main water stream. It is explained in detail during the Roomba alternative explanation of our recent seminar that is available online for those who want it. So, the greater the difference in pressure, the greater the vacuum, and, with that, the greater the efficiency of mixing.

If sized and installed correctly, a venturi can achieve a gas/water ratio of 1:1. (i.e. inject 1 litre of air/ozone into every litre of water that passes through it). For Liquid dosing, this ratio is a maximum of 1:10 (i.e. inject a maximum of 1 litre of the chemical into every 10 litres of water).

Venturis come in a number of different sizes. Size is determined not by the size of the pipeline into which it is installed, but rather by the pressure and flow rate of the water.