Light rainfall events account for over 97% of total annual rainfall. Therefore, it is particularly important to collect this light rain. With the PURAIN hydraulic jump filter, water is trapped in the trough, filtered and delivered into the tank. The trough ensures that no precious water is lost.
1. Inlet stainless steel slotted siev
2. Slotted siev
3. Collection area
4. Outlet of filtered water
5. Inspection shaft
Large precipitation events, which occur about 4 to 10 times a year and contribute only about 3% to the water yield, are used in the PURAIN rainwater filter for self-cleaning. These heavy precipitation events cause a vortex within the PURAIN rainwater filter, the so-called alternating jump. With its great energy, the alternating jump also whirls up the dirt that has accumulated in the trough and conveys it into the overflow.
1. Inlet stainless steel slotted siev
2. Slotted siev
3. Jump zone
4. Outlet of filtered water
5. Dirt drain/emergency overflow
6. Inspection shaft
In the event of a heavy rainfall event, the PURAIN rainwater filter therefore cleans itself. This means the lowest maintenance effort for the user compared to all other filter systems and an effective overall efficiency of 98%, which is unique for self-cleaning rainwater filters.
With the PURAIN filter, this water is collected in a trough, filtered and fed into the cistern. The trough guarantees that no valuable water is lost. In this test filter (see pictures), 3.5 kg of sand-gravel mixture was flushed away within 30 seconds with the aid of the alternating splash.
Read the expert opinion with a filter comparison test. (German)