Application
DF FDN low-pressure drainage filter set with state-of-the-art solution for the pressure filtration process with optimum performance. The innovative indirect air rinse system of the top layer of the filter bed allows for maximum elongation of the filter without damaging the filtrate. The use of low drainage eliminates the need to fill the filter with backing and intermediate layer, which allows for the use of a larger thickness bed without increasing the external dimensions.

Functioning
Water is introduced into the distribution crown of the device with the upper connector and then distributed over the surface of the filter bed. Flows through the filter media of the medium is purified from the compounds contained in raw water. The filtrate drain is realized through the cutter located at the bottom of the machine. The filter set is equipped with low-drainage drainage made of stainless steel with a 0.20 mm or 0.50 mm slot. The construction of a cross-sectional wire cap with a guide base in the direction of the filter bed, protects against clogging and overgrowth of grates making it easy to operate. The tapered distribution channel system with separated round openings for air distribution and triangular for rinsing water ensures even distribution of media during the filter bed rinsing with minimum pressure losses. The indirect air rinsing system used in the unit is based on a hexagonal distribution structure of rectangular cross-section. The rinse water is indirectly discharged through the drainage outlet protected against escaping the bed.

Equipment
- low pressure drainage filter with steel cover with aperture of 0.20mm or 0.50mm,
- Intermediate flushing system with compressed air of the top layer of the filter bed,
- two-way dash (optional),
- "air cushion" maintenance system (optional),
- Damper units with pneumatic actuators, with piping at the filter,
- fully autonomous automation system controlling the work of the device equipped with control module in three versions: basic, upper, pro,
- power supply and control cabinet equipped with control system, visualization of throttling state and compressed air distribution system,
- device wiring, compressed air supply,
- filter bed selected individually depending on physico-chemical parameters of treated water,
- material design: stainless steel. On request it is possible to use other constituent materials.

Product features
- Innovative solution for low pressure filter drainage and indirect air rinsing,
- removal of suspension, turbidity, color, as well as iron, manganese, ammonium and other compounds,
- elongation of the filter using a filter system (higher process efficiency),
- completely demolished drainage construction,
- slight drop in drainage pressure,
- high resistance to mechanical damage,
- drain construction: steel bottom plate equipped with impulse stabilized hydraulic system, tapered up distribution channel system with additional circular air distribution holes, and triangular for rinsing water, stainless steel 0.20 and 0.50 sealed cover made of profiled wire with a diagonal cross-section with a base pointing towards the fictitious bed,
- system drainage of the drainage system,
- Intermediate flushing system design: steel hexagonal distribution structure, plastic flushing nozzles extensively distributed on the filter surface.