How does a venturi work?
Venturis work on a 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. 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 maximum 1:10 (i.e. inject a maximum of 1 litre of 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.
“Fertigation is the injection of fertilizers, soil amendments, and other water-soluble products into an irrigation system.
Fertigation is related to chemigation, the injection of chemicals into an irrigation system. The two terms are sometimes used interchangeably however chemigation is generally a more controlled and regulated process due to the nature of the chemicals used. Chemigation often involves pesticides, herbicides, and fungicides, some of which pose health threat to humans, animals, and the environment.
Fertigation assists distribution of fertilizers for farmers. The simplest type of fertigation system consists of a tank with a pump, distribution pipes, capillaries, and a dripper pen.
All systems should be placed on a raised or sealed platform, not in direct contact with the earth. Each system should also be fitted with chemical spill trays.
Because of the potential risk of contamination in the potable (drinking) water supply, a backflow prevention device is required for most fertigation systems. Backflow requirements may vary greatly. Therefore, it is very important to understand the proper level of backflow prevention required by law.”