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.
Which venturi do I need?
Wassertec are agents for Mazzei Injectors, which are made in the USA. Mazzei venturi injectors are engineered from highly chemically resistant Kynar (PVDF) and are available in sizes ranging from ½ inch to 12 inch pipe diameter. We keep stock of models in the ½ inch to 3 inch range. Other sizes are available on request.
Contact us for more information
“The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section (or choke) of a pipe. The Venturi effect is named after Giovanni Battista Venturi (1746–1822), an Italian physicist.
The simplest apparatus is a tubular setup known as a Venturi tube or simply a venturi. Fluid flows through a length of pipe of varying diameter. To avoid undue aerodynamic drag, a Venturi tube typically has an entry cone of 30 degrees and an exit cone of 5 degrees.
Venturi tubes are used in processes where permanent pressure loss is not tolerable and where maximum accuracy is needed in case of highly viscous liquids
A venturi can also be used to mix a liquid with a gas. If a pump forces the liquid through a tube connected to a system consisting of a venturi to increase the liquid speed (the diameter decreases), a short piece of tube with a small hole in it, and last a venturi that decreases speed (so the pipe gets wider again), the gas will be sucked in through the small hole because of changes in pressure. At the end of the system, a mixture of liquid and gas will appear.”
(Source – Wikipedia)