Sand filters are employed for the effective filtration of algae, especially where large volumes of stored water are subject to daylight, such as lagoons and large open tank systems. Filtration is carried out through a deep bed of aggregate (coarse sand/fine gravel).
The degree of filtration largely depends upon the size of the aggregate particles and the depth of the filtration bed i.e. fine aggregate for drip systems and coarse aggregate for sprinklers. Water enters through the top inlet where it is sprayed over the top layer of the sand/aggregate.
As it percolates through the filtration media any organic material is trapped and clean water exits from the bottom of the tank. Finally, the clean water passes through a secondary screen filter to remove any broken-down sand particles that may have escaped.
As the filtration media becomes clogged with organic matter over time, the system is temporarily backflushed by reversing the flow of water. Any trapped organic matter is released and rises above the heavier aggregate to be flushed out of a top waste exit.
This process can be carried out automatically when a pressure differential is reached between the inlet and outlet pressures and is also backed up with a time-based backflush.
Sand filter arrays (several tanks abreast) can be installed where large flow rates are required and to allow individual tank backflushing without interrupting the irrigation cycle. Arrays can also be mounted on metal skids for use on remote sites such as field irrigation.
Sand filters are employed for the effective filtration of algae, especially where large volumes of stored water are subject to daylight, such as lagoons and large open tank systems. Filtration is carried out through a deep bed of aggregate (coarse sand/fine gravel).
The degree of filtration largely depends upon the size of the aggregate particles and the depth of the filtration bed i.e. fine aggregate for drip systems and coarse aggregate for sprinklers. Water enters through the top inlet where it is sprayed over the top layer of the sand/aggregate.
As it percolates through the filtration media any organic material is trapped and clean water exits from the bottom of the tank. Finally, the clean water passes through a secondary screen filter to remove any broken-down sand particles that may have escaped.
As the filtration media becomes clogged with organic matter over time, the system is temporarily backflushed by reversing the flow of water. Any trapped organic matter is released and rises above the heavier aggregate to be flushed out of a top waste exit.
This process can be carried out automatically when a pressure differential is reached between the inlet and outlet pressures and is also backed up with a time-based backflush.
Sand filter arrays (several tanks abreast) can be installed where large flow rates are required and to allow individual tank backflushing without interrupting the irrigation cycle. Arrays can also be mounted on metal skids for use on remote sites such as field irrigation.
