Application of Micro-irrigation Filters
Application of Micro-irrigation Filters
Sorting and filtering performance analysis of micro-irrigation filters
Micro-irrigation systems are more classification filter, the most common classification is based on the principle of filtration, filter media and different functions, divided into strainer, laminated filter, sand filters and hydrocyclones device.
1. The mesh filter
Strainer with wire or nylon mesh filter media, the water will flow through all larger than the mesh size of the suspended particles are trapped in the filter, the water flows out through the network core. Mesh filter cheap, easy maintenance, suitable for removing small sand and large inorganic debris, but less algae and other organic pollutants effects processing, particularly when greater pressure, a large amount of organic pollutants “squeeze “through the screen and into the pipe, causing micro-irrigation systems and irrigation is clogged, so that when high levels of organic pollutants in irrigation water, often and supporting the use of sand filter.
2. The laminated filter
Laminated filter can effectively remove organic and inorganic contaminants, both strainer and sand filter characteristics, by squeezing the laminations, in the upper and lower surfaces of each of the laminations are located a series of tiny filter tank, the filter tank can be much smaller than the filter cell size adsorption of impurities, and if a portion of the filter tank clogged filter will not affect the other adsorption tank, so greatly enhanced filtering capabilities. Due to the large laminated filter flow capacity, simple structure, reliable operation, it is widely used, but in the self-cleaning because the affected water organic and chemical contamination, there laminations are glued together and difficult to clean thoroughly Clean phenomenon.
3. sand filter
Sand filter sand filter medium is homogeneous, it is the use of dielectric absorption canister and filter head impure water will stop flowing through the filter into the water. Sand filter not only can effectively remove inorganic contaminants, but also containing organic contaminants and sludge quality most suitable filter type, with high decontamination capability, which relies mainly on the 30 ~ 50 cm thick medium, mechanical sieving, sedimentation and flocculation contacts to complete, so long as the content of organic pollutants in water 超过 1 0mg / L, no matter how many inorganic content, should be the choice of sand filter [1]. But this device is more expensive, higher management requirements, backwash if improper operation, it will make the entire sand bed filter movement which led to the failure.
4. hydrocyclone
Hydroclone common form of cylindrical and conical two, the working principle is to cut the high-speed rotation of the pressure to enter the water, resulting in strong centrifugal acceleration, so that the rapid separation of substances of different densities, the denser sand rotating along the wall to the bottom of the reservoir sand sink tank, while the less dense particles and water were the center of low pressure to the site and, in effect reverse high back pressure to the top of the overflow discharge port, into the downstream pipeline [2]. Therefore, the most appropriate treatment hydrocyclone contains a lot of water sand and stones, but can not be removed with a density similar to water and lighter than water, organic matter and other debris.
5. Other
When more debris in the water, not directly into the system, to be installed in the intake mesh trash racks or settling basin, as a primary source of irrigation water purification facilities to intercept litter Grottoes, remove solid material (mainly sediment ) and iron materials [3]. Such as low pressure at the inlet pipe, when not enough to run the filter, often require self-prepared pipe inlet filtration equipment (ie water evenly perforated PVC pipe and wrapped filter) to meet system filters and flow requirements. Impurities such as water and floating debris more network can be converted into a “filter box.” Usually a first large-scale micro-irrigation systems, the filtration device is a complex and huge, according to the different water conditions, select multiple filters combined into a multi-stage filtration system, the same type of filter to select multiple filter means based on traffic body composition filter sets. To consider the advantages of the two filters, consisting of good hydraulic performance, flow capacity of the combination type filter, such as centrifugation laminated combination filter, centrifugal strainer, laminated sand filters, etc., but because The water there is a special effect, such a filter than the local head loss is generally larger filter.
