Water sources contain various impurities to different extents. As the outlets of drip irrigation devices have very small apertures, it is easy for them to get clogged by impurities from the water source. Therefore, a strict filtering process for irrigation water sources is the essential first step in drip irrigation. It is a key measure for ensuring the normal operation of the drip irrigation system, extending the service life of the drip irrigation devices, and guaranteeing the quality of irrigation.
Centrifugal sand separator
This type of filter cleans solid particles whose density is higher than that of water based on the principles of gravity and centrifugal force. It needs to be cleaned and purified regularly, and the cleaning frequency depends on local water quality.The filtering effect can be affected by the unstable water flow during pumping or stopping. It is generally used as a primary filter in groundwater sources and is more effective when used together with a disc filter or a screen filter.
This type of filter uses sand and gravel as the filtering medium. It mainly cleans the suspended solids (such as algae) in the water and needs to have the sand and gravel replaced regularly, with the frequency depending on the local water quality. The filter must be used according to the designed flow rate. Too high a flow rate will result in a decrease in filtering accuracy, and backwashing should be performed when the inlet and outlet pressure drops exceed 0.07 MPa. It is generally used as a primary filter in surface water sources and is more effective when used together with a disc filter or a screen filter.
The filtering medium of this type of filter is either a nylon screen or a stainless steel screen. Impurities will be trapped in the screen wall while passing through the filter. It mainly cleans various impurities in the water and requires regular cleaning of the filter's screen. It is generally recommended that the filter be cleaned after each irrigation. The filter must be installed in accordance with the specified inlet water direction, and reverse use is prohibited. If it is found that the screen or sealing ring is damaged, it must be replaced in time. Otherwise, the filtering effect will be lost. It is generally used as a secondary filter together with a centrifugal sand separator and a sand filter.
This type of filter uses plastic discs with grooves as the filtering medium. The impurities will be trapped outside the discs while passing through the filter. It mainly cleans various impurities in the water and requires regular cleaning of the filter, with the cleaning frequency depending on the local water quality. The filter must be installed in accordance with the specified inlet water direction, and reverse use is prohibited. It is generally used as a secondary filter together with a centrifugal sand separator and a sand filter.
The equipment and devices that inject soluble fertilizers or pesticide solutions into the pressure pipeline in the drip irrigation system are called fertilization systems. The following are common types of fertilization systems:
Pressure difference fertilization system
With this type of system, fertilizers and pesticides are injected into the system by creating pressure difference between the two sub-valves of the fertilization valve. This system is easy to operate and applicable to a wide range of situations, but the fertilizer concentration gradually decreases during the fertilization process, and it is difficult to know the exact amount of fertilizer being applied. During use, make sure to tighten the cap of the fertilization tank.
Venturi fertilizer system
This system uses the Venturi effect to inject fertilizers and pesticides into the system. It has a simple structure, is easy to use, and the fertilization ratio is accurate. The fertilizer concentration is constant. However, the system needs to be connected in parallel with the main pipeline to overcome the disadvantage of a large water head loss. During use, adjust the fertilization speed as necessary.
This type of fertilization system relies on water pressure to drive an internal piston to inject fertilizers into the system. This system has a more complex structure, requires higher water pressure, has accurate fertilizer ratios, and keeps fertilizer concentration constant. Its price is relatively high. During use, adjust the fertilization ratio as necessary.
To ensure the normal operation of the drip irrigation system during fertilization, there are several points to note:
The fertilization system must be installed between the water source and the filter to prevent blockage of the irrigation device;
The pipes should be flushed with clean water after fertilization to prevent equipment corrosion;
A check valve must be installed between the water source and the fertilization system to prevent the pollution of the water source;
Dissolve the fertilizer first before applying it, and pour the supernatant into the fertilizer tank.