Fertilizer gets into the water through the differential pressure pump and then to the root system of the plant. Venturi pipes are installed at the head of the irrigation system, and in front of the filter.
Venturi injectors can be divided into several types with the diameter ranging from 90 to 32.
There's no essential difference, it's all the same. The venturi injector is installed in parallel with the control valve of the water supply pipe at the entrance of the micro irrigation system or irrigation area. When in use, the control valve is turned down to produce a certain pressure difference between the front and the back of the control valve, so that the water can smoothly pass through the branch pipe of the venturi injector. Through the vacuum suction generated by the water flow when it is passing through the venturi pipe, the fertilizer solution will be evenly sucked into the pipe system for fertilization.
The general choice is to use the fertilizer pot on the main pipe, and the specific size depends on the caliber. Choose venturi valve or fertilizer valve to apply fertilizer on the branch pipe according to a certain proportion, and the mixture ratio of water and fertilizer is fixed, which is adjustable and more stable. Advanced venturi are non-adjustable and unfixed in the ratio, and easy to use. In most cases, the venturi injector is mounted on a bypass pipe (parallel installation), so only a portion of the flow needs to pass through the injection section. This bypass operation allows the use of smaller venturi injector, which is easy to move. When no fertilizer is added, the system works normally. It can also be installed in series when the fertilization area is small and pressure loss is not considered. The enturi injector mounted on bypass pipes often makes use of the bypass pressure regulating valves to produce differential pressure. The loss of pressure head of the pressure regulating valve is sufficient to distribute pressure. If the fertilizer solution flows into the main pipe after filtration, the pumped fertilizer water should be filtered separately. Fertilizer suction mouth is often wrapped in the 100 to 120 mesh nylon mesh or stainless steel mesh. Or a corrosion-resistant filter is installed in the end of the conveying pipe of fertilizer solution with the screen size of 120 mesh. When some manufacturers finish the production, they have connected the stainless steel mesh at the end of the pipe. If necessary, the end structure of the conveying pipe shall be easy to be inspected and cleaned. The fertilizer pot should be lower than the jet pipe to prevent the flow of fertilizer fluid into the system under unnecessary pressure. Parallel installation can keep the pressure in the outlet constant and suitable for stable water flow. When inlet pressure is high, a small pressure regulating valve can be installed at the inlet end of the bypass pipe so that both ends have safety measures.
Since venturi injector is sensitive to pressure fluctuations during operation, a pressure gauge should be installed for monitoring. All system is typically equipped with multiple pressure gauges. The pressure gauge at both ends of the stop valve can measure the pressure difference at both ends of the stop valve. Some of the more advanced injectors are equipped with pressure gauges to monitor operating pressure.