For effective utilization of the small-scale and intricately designed Drip system, filtration becomes crucial. The system’s small components make proper filtration a necessity.
Without appropriate filtration, clogging emerges as a significant challenge in drip irrigation, ultimately affecting water delivery rates and causing wear and tear on irrigation components.
To address this issue, various types of filters have been developed. Here is a list of the different filter options used within the Drip Irrigation system.
Media Filter
Media filters are a popular method of filtration used in drip irrigation.
Media filters utilize media beds composed of sand, gravel, anthracite, crushed quartz, and other aggregates placed inside a cylindrical pressurized tank to process the water.
The tank, made of carbon steel, stainless steel, or fiberglass, works by forcing water through the dense media bed. As the water passes through, suspended particles become trapped within the spaces between the media. The media acts like a sieve, capturing particles while allowing clean water to pass through.
This process is both simple and effective in removing suspended solids, organic matter, and algae.
To manage buildup and clogging within the media bed, the filter contains a control head with a flush valve. During a flush cycle, the flush valve reverses the water flow, backwashing the media to discharge trapped particles from the system.
Although media filters are effective, it’s important to conduct periodic inspections and maintenance to ensure that the media bed is not congested with debris. The frequency of backwashing and flushing depends on the water quality.
Screen Filter
The screen filter is a basic low-cost, and low-maintenance filter using a mesh screen to remove particles and debris from the water.
Screens are typically made of metal, plastic, or synthetic cloth and are enclosed within a special housing. They usually consist of a coarse outer screen and a fine inner screen to ensure effective filtration.
Water is directed through a screen with micron-rated pores. Particles larger than the pore size are blocked by the screen, while water and smaller particles pass through.
Screen filters are categorized based on mesh size. Most screen filters offer a range of mesh sizes tailored to specific situations.
There are self-cleaning screen filters that utilize a wiper mechanism or reverse flow backflush to automatically clear debris from the screen surface, eliminating the need for manual cleaning.
The advantages of using screen filters include their compact size, affordability, and ease of maintenance. However, they possess a lower dirt holding capacity compared to media filters and are more susceptible to clogging.
Disk Filter
The Disk Filter is a more advanced filtration system compared to those previously mentioned on the list. It has the capability to filter out both inorganic and organic impurities, including algae.
As its name suggests, Disk Filter consists of the grooved disk forming a cylindrical filter with each groove crossing the other in different directions, creating a three-dimensional matrix of pathways. The disks are tightened firmly by a screw-on cap or by a spring that is compressed by a water piston.
The size of the groove determines the filtration grade. As water flows through the disk, the intersection of grooves provides in-depth filtering. Coarse particles are captured on the outer surface of the stack, while finer particles and organic debris adhere to the inner grooves.
The disks are automatically cleaned by internal jets. During the flushing cycle, water reverses its flow, slightly expanding the disk packs and dislodging collected particles from the grooves. Disk filters offer a high dirt-holding capacity and consistent filtration performance.
By utilizing the Disk Filter, you can effectively prevent clogging of drip emitters and optimize system performance. However, despite its effective filtration capabilities, the Disk Filter is pricier than screen or media filters. It’s primarily employed in scenarios requiring exceptionally clean water for irrigation, such as in greenhouses, nurseries, and systems using fine misters, foggers, or hydroponics.
Hydrocyclone Filter or Centrifugal Sand Separator
The Hydrocyclone Filter, though not exactly a traditional filter, employs centrifugal force to eliminate sand and other solid particles.
This filter removes the sand from groundwater extraction, which can cause severe damage to drip irrigation by slowing down water flow and clogging.
Structured in the form of a cone, the Hydrocyclone Filter features a collection chamber at its base. The water is introduced tangentially at the top of a cone creating a circular motion resulting in centrifugal force, which throws heavy suspended particles against the wall. The sand particles thrown against the container wall by the centrifugal force settle down and accumulate in a collecting chamber at the bottom.
The collector can be cleansed either manually or automatically. At the apex of the separator, clean water exits through an outlet.
Final Thoughts…
These filters are used in drip irrigation to enhance system efficiency and ensure effective irrigation.
In today’s context, most of the filters are becoming more advanced and come with automatic filter systems containing a controller, valves, and actuators to manage the backflush sequence. Automatic filters maintain optimal filtration and minimize maintenance requirements.
Thanks to automation, it is able remote filter stations to operate for long periods without manual intervention. And now, these automatic filters are often seen in permanent crops, golf courses, and municipal systems where labor costs are high.
Investing in filtration, which has automation functionality, can pay for itself through reduced maintenance costs.
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