A continuous, pressureless filter that washes itself while it runs — upward-flow filtration with an internal air-water backwash that removes captured solids without valves, backwash pumps or downtime.
Raw water enters at the base and rises through a deep bed of filter sand; suspended solids, turbidity and precipitated iron and manganese are captured as the water travels upward to the clean-water overflow.
An airlift continuously draws dirty sand from the bottom of the bed up a central pipe, where an air-water scour strips the captured solids from the grains — cleaning a small fraction of the bed at a time while the rest keeps filtering.
The patented sand-wash bath separates cleaned sand from the dirty washwater; clean, dense sand falls back to the top of the bed and the solids-laden reject leaves as a small continuous bleed.
A conventional rapid filter accumulates headloss until it must be taken offline and backwashed with a dedicated pump and valve sequence — losing 5–10% of throughput and creating downtime. The self-cleaning filter instead recirculates and washes its media continuously, so filtration headloss stays constant, only 2–4% of the filtered water is used for washing, and there are no automatic valves, no backwash pump and no interruption to the clean-water output. The trade is a steady low-energy air supply for the airlift in place of intermittent high-energy backwash pumping.
Because the bed is always partly fresh, filtrate quality is stable regardless of inlet variation, with no end-of-run turbidity breakthrough.
The only energy input is a low-pressure air blower; there are no valves or mechanical parts in the filtration zone to wear or fail.
Continuous low-rate washing uses far less water and power than batch backwashing, cutting both operating requirement and reject volume.
Reynolds & Bauhm sizes and supplies continuous self-cleaning filters matched to your water quality, duty and footprint.
Our expertise spans multiple industries with sector-specific water treatment solutions.