Abstract: A wastewater treatment device including a vessel having an inlet for receiving an influent stream, a grit outlet and a floating-matter outlet; a separator disposed within the vessel, wherein the separator comprises a tray assembly connected to the inlet and the grit outlet, the tray assembly including a plurality of nested tray units which define a separator axis and are spaced apart from one another along the separator axis, each tray unit having a substantially conical tray aligned along the separator axis and an aperture in the tray disposed at the separator axis and in communication with the grit outlet, wherein the wastewater treatment device further includes a spray nozzle configured to deliver a jet of fluid towards a surface of water within the vessel, wherein the spray nozzle is angled towards the direction of the floating-matter outlet to force floating matter accumulated on the surface of the water towards and out of the outlet.

Abstract: A vortex valve includes a housing having a cylindrical side wall and opposite ends to define a vortex chamber. The sidewall of the housing has a primary tangential inlet through which liquid may enter the vortex chamber in a manner to promote swirl within the vortex chamber and an outlet at one axial end of the vortex chamber. The outlet represents at least 50% of the area of the end of the vortex chamber in which it is situated and in the vortex chamber has a length which is at least one and a half times the diameter of the outlet. The vortex valve requires only a low head to initiate vortex flow.

Abstract: There is disclosed a separation vessel which is defined by a cylindrical wall (2) and a base (38), there being a solids collection region (12) centrally disposed of the base (38), an outlet (8) disposed in an upper region of the vessel, and a flow modifying member (14) positioned adjacent the base (38), the arrangement of the vessel being such that liquid carrying particulate material may flow upwardly to the top of the vessel toward the outlet (8) in a substantially axial direction. Also disclosed is a method of separating components of a liquid mixture from each other and a method of classifying a particulate material.

Abstract: There is described a low energy separator for separating solid components out of a liquid mixture, comprising (a) a vessel having a cylindrical outer wall and a base at one end, (b) a body which is provided within the vessel and which defines with the base an annular opening spaced from the outer wall, (c) an inlet for introducing the liquid mixture into the vessel said inlet opening directly into the vessel, (d) an outlet in the upper region of the vessel for removing from the vessel liquid from which solid components have been separated, (e) a primary annular dip plate extending downwardly toward the base from an upper region of the vessel and spaced from the outer wall of the vessel, and (f) means for promoting a rotational movement of liquid and suspended solids within the vessel, said rotational movement being sufficient to cause or enhance an inward sweeping effect towards the annular opening on solids accumulated at the base of the vessel, while being of sufficiently low energy that separation of the s

Abstract: There is disclosed a separator of the low energy type comprising a cylindrical vessel (1) in which rotational movement of liquid and suspended solids within the vessel (1) is sufficient to cause and enhance an inward sweeping effect towards an annular opening in the base (3) on solids accumulated at the base (3) of the vessel (1), while being of sufficiently low energy that separation of the solid components of the liquid in the vessel (1) is brought about primarily by gravity. In order to trap floatables material, a floatables trap (19) is provided inward of an annular dip plate (9) in the vessel (1).

Abstract: There is disclosed a low energy separator of the type comprising a vessel (1) in which rotational movement of liquid in the vessel is sufficient to cause or enhance an inward sweeping effect towards an annular opening in the base (3) of the vessel on solids accumulated at the base of the vessel (1) while being of sufficiently low energy that separation of the solids components in the liquid in the vessel (1) is brought about primarily by gravity. In order to reduce turbulence caused by the outlet (7) in the upper region of the vessel (1), a flow modifying means (14) is provided which guides liquid circulating in the vessel (1) at an upper region thereof to a level at or below the lower level of the outlet (7).

Abstract: A method for separating a first, relatively dense and hard component of a liquid mixture from a second, less dense and relatively soft component of the mixture. The method comprises introducing the liquid mixture into a settlement vessel (3); abstracting the settled solids from the settlement vessel (3) and passing the abstracted, settled solids through a shearing means (22); and returning the abstracted, sheared solids to the settlement vessel (3) thereby to permit the relatively hard component of the liquid mixture to settle and separate from the relatively soft component. An apparatus for separating a first, relatively dense and hard component of a liquid mixture from a second, less dense and relatively soft component of the mixture.

Abstract: There is provided a vortex-valve which comprises a housing defining a vortex chamber, a housing having an inlet through which liquid may enter the vortex chamber in manner to promote swirl within the vortex chamber and an outlet at one axial end of the vortex chamber. A wall of the housing is provided with an opening which is normally closed by a closure, this closure being operable between the closed position and an open position in which liquid may enter the vortex chamber by-passing the inlet. The vortex-valve may be provided at the outlet of a gully and is useful in enabling a blockage, which may occur at the inlet of the vortex-valve, to be by-passed, thereby draining any accumulated liquid in the gully. The blockage may then be removed when the gully is relatively dry.

Abstract: A separator comprises a vessel having an outer wall (2) and an end wall (3). A body (14) adjacent the end wall (3) defines with the end wall (3) an annular opening (15). In use, a mixture of, for example water and solid material, is introduced into the vessel through a first inlet (4). A circulating motion takes place in the vessel and the solid material falls to the end wall (3) and is removed through the opening (15) to an outlet (6) while clean water flows from the top of the vessel through an outlet (8). In order to increase the energy in the lower region of the vessel so as to assist removal of the solid material, water from the outlet (8) is passed through a pump (P) and reintroduced as energizing fluid to the vessel through a recirculating port (44). Energizing fluid may be taken from sources other than the outlet (8). Various alternative forms of separator are disclosed.

Abstract: A method of treating water comprises adding to the water a composition comprising a weighting agent and an electrolyte having a multivalent metal cation.The resultant floc absorbs suspended solids in the water and gives rise to a dense sludge which is easily removed from the purified supernatant liquor. A composition for use in the method is also disclosed. The composition may be in the form of a slurry or a friable solid (which may be briquetted).

Abstract: A separator comprises a vessel having an outer wall (2) and an end wall (3). A body (14) adjacent the end wall (3) defines with the end wall (3) an annular opening (15). In use, a mixture of, for example, water and solid material is introduced into the vessel through a first inlet (4). A circulating motion takes place in the vessel and the solid material falls to the end wall (3) and is removed through the opening (15) to an outlet (6) while clean water flows from the top of the vessel through an outlet (8). In order to increase the energy in the lower region of the vessel so as to assist removal of the solid material, water from the outlet (8) is passed through a pump (P) and reintroduced as energizing fluid to the vessel through a recirculating port (44). Energizing fluid may be taken from sources other than the outlet (8). Various alternative forms of separator are disclosed.