초록

A rain head is disclosed having three filters through which water entering an inlet to the rain head must pass before passing out through an outlet from the rain head. The filters remove successively smaller particles from the water.

대표청구항 ▼

I claim: 1. A rain head having an inlet and an outlet, at least a primary filter through which water may pass and a secondary filter through which water passing through the primary filter may flow, the secondary filter filtering smaller particles from the water than the primary filter, the rain hea

I claim: 1. A rain head having an inlet and an outlet, at least a primary filter through which water may pass and a secondary filter through which water passing through the primary filter may flow, the secondary filter filtering smaller particles from the water than the primary filter, the rain head having a downpipe connecting portion extending therefrom and a free end of the connecting portion providing the inlet from the rain head, wherein at least one of the primary filter and the secondary filter has a peaked portion spaced from sides of the filter and downwardly sloping portions extending from the peak to the sides, whereby particles caught by the filters may be washed to the sides of the filter to minimize restriction of water flow through the filters. 2. The rain head of claim 1 wherein the primary filter is a filter screen. 3. The rain head of claim 2 wherein the screen consists of woven stainless steel. 4. The rain head of claim 3 wherein the screen has an aperture size of 4 to 6 mm. 5. The rain head of claim 2 wherein the screen has an aperture size of 4 to 6 mm. 6. The rain head of claim 1 wherein the secondary filter is a filter screen. 7. The rain head of claim 6 wherein the screen has an aperture size of 1 to 1.5 m. 8. The rain head of claim 6 wherein the screen consists of woven stainless steel. 9. The rain head of claim 8 wherein the screen has an aperture size of 1 to 1.5 m. 10. The rain head of claim 1 including a tertiary filter located between the secondary filter an the outlet, the tertiary filter filtering smaller particles from the water than the secondary filter. 11. The rain head of claim 10 wherein the tertiary filter consists of one or more layers of geotextile fabric. 12. The rain head of claim 11 wherein the tertiary filter has a drop cone characteristic of between H50 6400 to H20 12600 per layer, a CBR burst strength of between 5100 N@60% to 9600 N@60% per layer, a tensile strength of between 33 kN/m횞D/18 kN/m MD to 68 kN/m D/38 kN/m MD per layer, a pore size between 100 mm to 90 mm per layer and a flow rate of between 80 Lm2/s to 65 Lm2/ s per layer. 13. The rain head of claim 11 wherein the geotextile fabric is non-woven. 14. The rain head of claim 13 wherein the fabric has a thickness between 4.8 to 5.7 mm. 15. The rain head of claim 14 wherein the tertiary filter has a drop cone characteristic of between H50 6400 to H20 12600 per layer, a CBR burst strength of between 5100 N@60% to 9600 N@60% per layer, a tensile strength of between 33 kN/m횞D/18 kN/m MD to 68 kN/m D/38 kN/m MD per layer, a pore size between 100 mm to 90 mm per layer and a flow rate of between 80 Lm2/s to 65 Lm2/ s per layer. 16. The rain head of claim 13 wherein the tertiary filter has a drop cone characteristic of between H50 6400 to H20 12600 per layer, a CBR burst strength of between 5100 N@60% to 9600 N@60% per layer, a tensile strength of between 33 kN/m횞D/18 kN/m MD to 68 kN/m D/38 kN/m MD per layer, a pore size between 100 mm to 90 mm per layer and a flow rate of between 80 Lm2/s to 65 Lm2/ s per layer. 17. The rain head of claim 10 wherein the tertiary filter separates particles down to 50 micron from the water that passes through it. 18. The rain head of claim 1 wherein both the primary and secondary filters have peaked portions spaced from sides of the filter and downwardly sloping portions extending from the peaks to the sides. 19. The rain head of claim 1 having a stepped periphery. 20. The rain head of claim 1 having a downpipe connecting portion extending therefrom and a free end of the connecting portion providing the inlet from the rain head.