The use of reclaimed water or other lower quality water sources is becoming more common in irrigation projects, whether commercial or residential.
This is partly the result of reduced availability of clean, fresh water sources and the challenge for contractors or landscape designers is to ensure that irrigation systems work effectively, whatever the source.
To address the issue, Rain Bird now offers the HDF Series of automatic self-cleaning disc filtration equipment.
Rain Bird filtration products including pump suction screens, centrifugal sand separators and hydraulic suction screen filters are already available. These offer different levels of filtration and modes of operation. However, using water from canals, ponds, rivers, wells, reservoirs or waste water sources for irrigation requires a more thorough approach to filtration. It is essential that contaminants which originate from organic and inorganic matter, such as algae, sand, silt, suspended solids and microbiological growth, are filtered out. This will prevent nozzles, rotors, valves and other equipment being blocked or even damaged, resulting in efficient flow rates and optimised water usage.
Within an irrigation circuit, the HDF Series will act as a primary filter for the water source and is located after the pump. Having then passed through backflow and master valve stations, the filtered uncontaminated water is then distributed via any secondary filters to the chosen nozzles, rotors or in-line drip irrigation. The Rain Bird irrigation controller is highly flexible and allows filtration and cleaning cycles to take place without any interruption to flow to the system.
The HDF Series is specifically designed to be used within irrigation systems where manual cleaning would be difficult, time consuming or unwieldy. Three different units provide varying levels of filtration efficiency and capacity. For flexibility, they can operate with or without electricity and include control units that run on 220V AC or 12V DC. The units are manufactured from tough engineered plastics and materialsresistant to rust and corrosion from chemicals or water.
Units are pre-assembledand wired for easy installation. All HDF units feature a patented anti-clogging device that generates a helical centrifuge effect moving a high percentage of particles that are suspended in water away from the disk. This ensures optimal performance resulting in water savings, reduced backwash frequency and minimum maintenance requirements.
Choosing the correct HDF Series unit is based on establishing the quality and dirtiness of the water source, determining the required filtration grade and then calculating the number of filters required. The filter cartridge is made up of a number of stacked discs. Water passes through small grooves between the discs which are compressed and impurities are trapped and projected away through the cyclone effect. During back flushing, water is projected through the discs evacuating the contaminant particles through the drainage manifold. The filtration process restarts when the discs recompress. The systems automatically measure the pressure over the filters to determine when back washing and cleaning are required.
HDF 1x2, HDF 2 and HDF 4 designations refer to the size of the filters and the on-board valves. The HDF 4 is a scalable multi-filter unit with standard filtration of 100, 130 and 400 microns with custom options available. Users can add a number of filters to the specification in order to reach the desired flow rates for the application. Up to twelve, 4-inch filters can be used to achieve maximum flow rates of 575 m³ per hour. The elements inside the filter provide depth filtration across the diameter, not just at the circumference and the helical action inside ensures highly efficient cleaning.
The HDF 2 is also multi-filter and scalable, using up to eight 2-inch filters for a maximum throughput of 192m³ per hour. The single HDF 1 with a single two inch filter is designed for low flow applications and has a maximum throughput of 24 m³ per hour. Its compact design makes it ideal for fitting into tight spaces and is typically well suited to turf irrigation applications.
