Abstract: A separator, for separating solids from a liquid, comprises a hydrodynamic separator, a first filtration device, a first backwash device, a second filtration device, and a second backwash device. The first filtration device comprises a first inlet at a first level for receiving at least a first portion of the liquid from the hydrodynamic separator, and a first filter for filtering the first portion of the liquid received via the first inlet. During filtration of the first portion of the liquid, the first portion of the liquid passes through the first filter away from the first inlet and a first portion of solids is retained by the first filter. The first filter is located between the first inlet and the first backwash device.

Abstract: There is described a drainage system comprising: an inlet pipe; and an energy dissipater comprising a dissipation chamber. The dissipation chamber has a dissipater inlet fluidically connected to the inlet pipe and a dissipater outlet arranged to discharge fluid from the dissipation chamber. The dissipater inlet extends between a first end and a second end. A wall of the inlet pipe extends tangentially from the dissipation chamber so as to define the first end and such that, in use, fluid is discharged into the dissipation chamber in a tangential direction, thereby inducing a circulating flow within the dissipation chamber about an axis of the dissipation chamber. The width of the dissipater inlet in a direction parallel to the axis decreases from the first end to the second end.

Abstract: A separator, for separating solids from a liquid, comprises a hydrodynamic separator, a first filtration device, a first backwash device, a second filtration device, and a second backwash device. The first filtration device comprises a first inlet at a first level for receiving at least a first portion of the liquid from the hydrodynamic separator, and a first filter for filtering the first portion of the liquid received via the first inlet. During filtration of the first portion of the liquid, the first portion of the liquid passes through the first filter away from the first inlet and a first portion of solids is retained by the first filter. The first filter is located between the first inlet and the first backwash device.

Abstract: There is described a drainage system comprising: an inlet pipe; and an energy dissipater comprising a dissipation chamber. The dissipation chamber has a dissipater inlet fluidically connected to the inlet pipe and a dissipater outlet arranged to discharge fluid from the dissipation chamber. The dissipater inlet extends between a first end and a second end. A wall of the inlet pipe extends tangentially from the dissipation chamber so as to define the first end and such that, in use, fluid is discharged into the dissipation chamber in a tangential direction, thereby inducing a circulating flow within the dissipation chamber about an axis of the dissipation chamber. The width of the dissipater inlet in a direction parallel to the axis decreases from the first end to the second end.

Abstract: A drainage system, comprising a collector which is arranged to collect liquid and a drainage pipe having a pipe inlet that opens into the collector such that liquid collected by the collector drains through the pipe inlet. The drainage pipe is provided with a vent spaced away from the pipe inlet. The vent is arranged such that, when liquid collected by the collector occludes the pipe inlet, liquid flowing through the drainage pipe draws air into the drainage pipe through the vent.

Abstract: A drainage system, comprising a collector which is arranged to collect liquid and a drainage pipe having a pipe inlet that opens into the collector such that liquid collected by the collector drains through the pipe inlet. The drainage pipe is provided with a vent spaced away from the pipe inlet. The vent is arranged such that, when liquid collected by the collector occludes the pipe inlet, liquid flowing through the drainage pipe draws air into the drainage pipe through the vent.

Abstract: A drainage system, comprising a collector which is arranged to collect liquid and a drainage pipe having a pipe inlet that opens into the collector such that liquid collected by the collector drains through the pipe inlet. The drainage pipe is provided with a vent spaced away from the pipe inlet. The vent is arranged such that, when liquid collected by the collector occludes the pipe inlet, liquid flowing through the drainage pipe draws air into the drainage pipe through the vent.

Abstract: A method of configuring a vortex flow control device 2 comprising a vortex chamber 4, an inlet 6 and an outlet 8 arranged at one end of the vortex chamber 4, wherein the method comprises the steps of: setting a target maximum flow rate FT-MAX through the outlet 8 for a predetermined pressure PT-MAX at the inlet; setting a target vortex initiation flow rate FT-VI through the outlet 8 at which vortex flow within the vortex chamber 4 initiates; determining the actual maximum flow rate FA-MAX through the outlet 8 for the predetermined pressure PT-MAX at the inlet 6; determining the actual vortex initiation flow rate FA-VI through the outlet 8; determining an error parameter E based on at least one of the actual maximum flow rate FA-MAX and the actual vortex initiation flow rate FA-VI and at least one of the target maximum flow rate FT-MAX and the target vortex initiation flow rate FT-VI; comparing the error parameter E against a target condition CT; and, if the error parameter E fails to satisfy the target condit

Abstract: A drainage system, comprising a collector which is arranged to collect liquid and a drainage pipe having a pipe inlet that opens into the collector such that liquid collected by the collector drains through the pipe inlet. The drainage pipe is provided with a vent spaced away from the pipe inlet. The vent is arranged such that, when liquid collected by the collector occludes the pipe inlet, liquid flowing through the drainage pipe draws air into the drainage pipe through the vent.

Abstract: A method of configuring a vortex flow control device 2 comprising a vortex chamber 4, an inlet 6 and an outlet 8 arranged at one end of the vortex chamber 4, wherein the method comprises the steps of: setting a target maximum flow rate FT-MAX through the outlet 8 for a predetermined pressure PT-MAX at the inlet; setting a target vortex initiation flow rate FT-VI through the outlet 8 at which vortex flow within the vortex chamber 4 initiates; determining the actual maximum flow rate FA-MAX through the outlet 8 for the predetermined pressure PT-MAX at the inlet 6; determining the actual vortex initiation flow rate FA-VI through the outlet 8; determining an error parameter E based on at least one of the actual maximum flow rate FA-MAX and the actual vortex initiation flow rate FA-VI and at least one of the target maximum flow rate FT-MAX and the target vortex initiation flow rate FT-VI, comparing the error parameter E against a target condition CT; and, if the error parameter E fails to satisfy the target condit

Abstract: A stormwater gully comprises a chamber in which an outlet assembly is installed. The outlet assembly comprises filter units connected to an outlet housing. In use, stormwater can flow from the chamber in an upwards direction through filter units into the outlet housing. The outlet housing has an outlet, which extends from the gully. At high rates of flow, the water level in the chamber will rise until water can flow into the outlet housing through bypass inlets. The bypass inlets are connected to the interior of the housing by siphons defined by arched regions of a top cover. The siphons allow rapid discharge of water until the water level returns below the level of the bypass inlets. A slow drain down feature is provided which enables the chamber and outlet assembly to be drained below the level of the primary inlet.

Abstract: A stormwater gully comprises a chamber in which an outlet assembly is installed. The outlet assembly comprises filter units connected to an outlet housing. In use, stormwater can flow from the chamber in an upwards direction through filter units into the outlet housing. The outlet housing has an outlet, which extends from the gully. At high rates of flow, the water level in the chamber will rise until water can flow into the outlet housing through bypass inlets. The bypass inlets are connected to the interior of the housing by siphons defined by arched regions of a top cover. The siphons allow rapid discharge of water until the water level returns below the level of the bypass inlets. A slow drain down feature is provided which enables the chamber and outlet assembly to be drained below the level of the primary inlet.

Abstract: A stormwater gully comprises a chamber in which an outlet assembly is installed. The outlet assembly comprises filter units connected to an outlet housing. In use, stormwater can flow from the chamber in an upwards direction through filter units into the outlet housing. The outlet housing has an outlet, which extends from the gully. At high rates of flow, the water level in the chamber will rise until water can flow into the outlet housing through bypass inlets. The bypass inlets are connected to the interior of the housing by siphons defined by arched regions of a top cover. The siphons allow rapid discharge of water until the water level returns below the level of the bypass inlets. A slow drain down feature is provided which enables the chamber and outlet assembly to be drained below the level of the primary inlet.

Abstract: A stormwater gully comprises a chamber in which an outlet assembly is installed. The outlet assembly comprises filter units connected to an outlet housing. In use, stormwater can flow from the chamber in an upwards direction through filter units into the outlet housing. The outlet housing has an outlet, which extends from the gully. At high rates of flow, the water level in the chamber will rise until water can flow into the outlet housing through bypass inlets. The bypass inlets are connected to the interior of the housing by siphons defined by arched regions of a top cover. The siphons allow rapid discharge of water until the water level returns below the level of the bypass inlets. A slow drain down feature is provided which enables the chamber and outlet assembly to be drained below the level of the primary inlet.

Abstract: A vortex flow control device is manufactured by forming a template unit having end walls of which the wall has an outlet opening, and a partial outer wall. The partial outer wall has an opening. A plate is subsequently secured to the template unit to partially close the opening, to leave an inlet. The size of the plate is selected so as to result in an inlet 30 sized to achieve required flow characteristics for the finished device. The plate is inclined to a planar portion on the opposite side of the inlet at an angle in the range 85° to 95°, so as to induce turbulence in the region of the inlet.

Abstract: A separator comprises a gully chamber 2 having inlet and outlet ducts 10, 12. Inlet and outlet housings 20, 22 are disposed within the separator and are connected by a bypass duct 24 which extends around the wall of the chamber 2. Flow enters the chamber through an inlet which is oriented to create a circulating flow. Flow exits from the chamber through an outlet opening provided in the outlet housing 22. The outlet opening is oriented in the direction of the circulating flow so that liquid has to reverse from that flow to pass through the outlet opening. The inlet and outlet housings 20, 22 are made from identical mouldings in which appropriate openings are formed. The bypass duct can be cut to length to position the inlet and outlet housings 20, 22 opposite existing inlet and outlet ducts 10, 12.

Abstract: An overflow chamber (2) is provided for use in a combined sewer overflow. An inlet (12) and an outlet (14) open into the chamber (2) below a screen (20), and an overflow outlet (15) opens into the chamber above the screen. Baffles (26) are provided underneath the screen (20) across the general flow of storm water. In storm conditions, the storm water in the chamber (2) will reach the level of the screen (20), which traps aesthetically offensive material and gross solids, leaving the water to flow through the screen (20) to the overflow outlet (15). The baffles (26) circulate the storm water, and this dislodges material accumulated on the underside of the screen (20) and so helps to prevent blinding of the screen (20) in storm conditions.

Abstract: A separator comprises a gully chamber 2 having inlet and outlet ducts 10, 12. Inlet and outlet housings 20, 22 are disposed within the separator and are connected by a bypass duct 24 which extends around the wall of the chamber 2. Flow enters the chamber through an inlet which is oriented to create a circulating flow. Flow exits from the chamber through an outlet opening provided in the outlet housing 22. The outlet opening is oriented in the direction of the circulating flow so that liquid has to reverse from that flow to pass through the outlet opening. The inlet and outlet housings 20, 22 are made from identical mouldings in which appropriate openings are formed. The bypass duct can be cut to length to position the inlet and outlet housings 20, 22 opposite existing inlet and outlet ducts 10, 12.

Abstract: An overflow chamber (2) is provided for use in a combined sewer overflow. An inlet (12) and an outlet (14) open into the chamber (2) below a screen (20), and an overflow outlet (15) opens into the chamber above the screen. Baffles (26) are provided underneath the screen (20) across the general flow of storm water. In storm conditions, the storm water in the chamber (2) will reach the level of the screen (20), which traps aesthetically offensive material and gross solids, leaving the water to flow through the screen (20) to the overflow outlet (15). The baffles (26) circulate the storm water, and this dislodges material accumulated on the underside of the screen (20) and so helps to prevent blinding of the screen (20) in storm conditions.