Filter for polluted water

Abstract

An apparatus for filtering polluted water in drainage systems. The apparatus comprising a collection chamber for collecting the water, having a first end, a second end opposite the first end, and two sides between the ends. An inlet is disposed at or near the first end for the water to enter the collection chamber and a filter screen is disposed in the sides through which the water exits the collection chamber. A deflector is disposed at or near the second end of the collection chamber to deflect downwardly the water flowing towards it.

1 . An apparatus for filtering polluted water in drainage systems, comprising
 a collection chamber for collecting the water, having a first end, a second end opposite the first end, and two sides between the ends;   an inlet at or near the first end for the water to enter the collection chamber; and   at least one filter screen disposed in at least one of the sides through which the water exits the collection chamber;   characterised in that a deflector is disposed at or near the second end of the collection chamber, the deflector being arranged to deflect downwardly the water flowing towards it, so that as the water flows through the collection chamber at least a portion of it tumbles about a substantially horizontal axis such that at the centre of the collection chamber the water near the surface flows substantially towards the second end, and the water near the bottom of the collection chamber flows substantially towards the first end.   
     
     
         2 . An apparatus for filtering polluted water as claimed in  claim 1 , wherein the deflector establishes a laminar flow state in the water in the vicinity of the deflector. 
     
     
         3 . An apparatus for filtering polluted water as claimed in  claim 1 , wherein the collection chamber is elongate such that the distance between the ends of the collection chamber is greater than the distance between the sides of the collection chamber. 
     
     
         4 . An apparatus for filtering polluted water as claimed in  claim 1 , wherein the deflector is at least partially submerged when the water is flowing though the apparatus. 
     
     
         5 . An apparatus for filtering polluted water as claimed in  claim 1 , wherein at least a portion of the deflector is shaped such that the distance between the front of the portion and the first end of the collection chamber increases as the portion extends towards the bottom of the collection chamber. 
     
     
         6 . An apparatus for filtering polluted water as claimed in  claim 1 , wherein the deflector comprises an array of spaced apart elements, disposed parallel to the flow of the water past the deflector. 
     
     
         7 . An apparatus for filtering polluted water as claimed in  claim 1 , further comprising an oil separator for removing oil from the water, the oil separator being attached to or integral with the deflector. 
     
     
         8 . An apparatus for filtering polluted water as claimed in  claim 7 , wherein the deflector comprises the oil separator, and the deflector comprises an array of spaced apart elements disposed parallel to the flow of the water past the deflector, and each element comprises an oil absorption material. 
     
     
         9 . An apparatus for filtering polluted water as claimed in  claim 6 , wherein each element has a smooth front edge that faces the flow of the water towards the deflector. 
     
     
         10 . An apparatus for filtering polluted water as claimed in  claim 1 , wherein the inlet is a pipe, and the distance between the first and second ends of the collection chamber is at least four times the diameter of the pipe. 
     
     
         11 . An apparatus for filtering polluted water as claimed in  claim 1 , further comprising a discharge chamber and an outlet, wherein the water passing through the filter screen flows into the discharge chamber, and then out of the apparatus through the outlet. 
     
     
         12 . An apparatus for filtering polluted water as claimed in  claim 1 , wherein the filter screen is replaceable. 
     
     
         13 . An apparatus for filtering polluted water as claimed  1 , wherein the filter screen comprises at least two modular panels. 
     
     
         14 . An apparatus for filtering polluted water as claimed in  claim 1 , wherein the filter screen is made from at least one plastic material. 
     
     
         15 . An apparatus for filtering polluted water as claimed in  claim 7 , wherein the apparatus comprises a winch system for lowering and raising the oil separator into the collection chamber. 
     
     
         16 . (canceled) 
     
     
         17 . (canceled) 
     
     
         18 . (canceled) 
     
     
         19 . A stormwater contaminant separator and collector device for installation with stormwater pipes, said device comprising
 a collection chamber for collecting water, having a first end, a second end opposite the first end, and two sides between the ends;   a stormwater inlet at or near said first end for said water to enter the collection chamber; and   at least one filter screen disposed in at least one of said sides through which said water exits said collection chamber, characterised in that   a deflector structure is disposed at or near said second end of said collection chamber, at least a portion of said deflector structure being arranged to deflect downwardly water flowing towards it, and as said water flows through said collection chamber at least a portion thereof tumbles about a substantially horizontal axis such that at the centre of said collection chamber said water near the surface flows substantially towards said second end, and said water near the bottom of said collection chamber flows substantially towards said first end.   
     
     
         20 . A stormwater contaminant separator and collector device as claimed in  claim 19 , wherein solid pollutants are substantially deposited in an area below said inlet at or near said first end, and buoyant pollutants are collected in an upper central zone of said collection chamber between said first and second ends. 
     
     
         21 . A stormwater contaminant separator and collector device as claimed in  claim 19 , wherein an oil and scum collection zone is disposed at or near said deflector structure at said second end. 
     
     
         22 . A method of separating stormwater contaminants by passing polluted stormwater through a collection chamber, said method comprising imparting a tumbling motion about a substantially horizontal axis to a portion of the flow entering said collection chamber through an inlet, such that said portion of flow is directed downwardly and back towards said inlet. 
     
     
         23 . A stormwater contaminant separator and collector device as claimed in  claim 20 , wherein an oil and scum collection zone is disposed at or near said deflector structure at said second end.