Abstract: A grit extractor includes inlet and outlet flumes arranged to inject and extract liquid tangentially into a round chamber. The velocity entering and leaving the chamber is controlled by the width of the outlet flume. The velocity is maintained within an optimal region over a ten to one flow range. An effective ten to one variation in flow is achieved with a velocity in the range of 1.5 feet per second to 3.5 feet per second.

Abstract: An aerator for a water treatment plant or water conditioning application, includes a draft tube for vertical positioning within a volume of water and an outlet structure overlying a top open end of the draft tube. Water is lifted or pumped through the draft tube out of the top open end. The outlet structure includes a stepped splash plate which deflects the water flowing out of the top open end in a cascading fashion which increases the oxygenation efficiency and spray pattern of the thus aerated water. Additionally, a blinder bracket is applied to the outlet structure to reduce flow from the outlet structure at a particular preselected arc. The draft tube and outlet structure can be molded as a unitary plastic piece, and flow windows and openings can be cut into the piece.

Abstract: An apparatus for wastewater treatment, includes a calorie reducer first vessel having an inlet and an outlet, the outlet adapted to control the retention time of wastewater within the first vessel. A first recycle pump is connected to the first vessel to recycle wastewater from a bottom of the first vessel to a top of the first vessel through a recycle conduit, at a high velocity. The recycle conduit provides an air gap for drawing air into the first vessel. Bacteria within the calorie reducer vessel consume biodegradable food with a minimum number of bacteria while in the log growth phase. A second bio-reducer vessel is connected to the calorie reducer vessel. The bio-reducer holds a media supported above a bottom reservoir. A bio-reducer recycle pump recycles wastewater within the reservoir to be sprayed onto a top of the bio-reducer, to wash over the media. Further bio-reducers can be arranged downstream of the first bio-reducer.

Abstract: A single port pump impeller includes two pump vanes diverging arcuately and radially from a suction eye to form one open expanding chamber, and includes a blocking wall for closing the remaining, opposite expanding chamber. The two vanes are contained within parallel spaced apart shrouds. The shrouds include increased wall thickness regions to dynamically balance the impeller. The blocking wall can include a small aperture for providing a small stream of liquid to flow into the otherwise closed expanding chamber to prevent cavitation at a distal end of an adjacent vane. Alternately, the otherwise blocked expanding chamber can be filled with a solid material having substantially the same weight as the fluid being pumped, e.g., water, to prevent cavitation at the outside edge of one of the adjacent vanes.

Abstract: A method and apparatus for treatment of biodegradable waste products. The influent is aerated and directed through a fixed media assembly to promote intimate surface contact and cause microbial growth. The fixed media assembly comprises a stack of spaced apart, parallel, substantially vertical corrugated sheets. The corrugations are defined by obliquely inclined peaks and valleys and are oriented so that the corrugations of immediately adjacent sheets intermate with one another so as to define an inclined sluffing channel at each corrugation to provide a substantially unobstructed pathway therethrough while inducing turbulence and mixing.

Abstract: A radial mixing header for use with apparatus that removes solids from a liquid by dissolved air flotation (DAF). The header comprises a par of concentric pipes circumscribed by a concentric mixing chamber having a tangential port for introduction of the recycled gas-liquid stream thereinto. The recycled stream achieves rotary and turbulent motion and mixes in a larger diameter pipe with the raw solids-containing stream which flows through a smaller diameter pipe.

Abstract: An improved method and apparatus for treating liquor containing biodegradable wastes wherein the liquor is first delivered to a quiescent primary settling zone and then to an aeration zone. The aerated liquor is delivered downwardly through a column of submerged fixed media having a high surface area to volume ratio so that aerobic microorganisms can grow on their surface. The liquor is recirculated through the aeration zone and fixed media, and is withdrawn from the unit after treatment. A portion of the aerated liquor from the top of the fixed media is recycled back into the primary settling zone to denitrify the nitrate rich aerated liquor by deoxygenating the dissolved nitrates and to equalize the BOD load in the secondary aerobic treatment zone.

Abstract: An oxidation ditch for biological aerobic treatment of wastewater having a velocity control system to establish an increased and more uniform cross-sectional velocity throughout the flow channel. The system includes a turning baffle member positioned in at least one of the end sections of the flow channel. The turning baffle member is provided with an end portion that has an upper edge that extends under a brush aerator located across an elongated section of the flow channel. The upper edge of the other portion of the turning baffle member extends above the surface of the flowing mixed liquor stream. The flow of the mixed liquor downstream of the brush aerator is unrestricted by flow baffles located in the flow channel.

Abstract: A vacuum priming system for drawing liquid into the pumping chamber to prime a vertical shaft centrifugal pump for pumping sewage or the like. The vacuum priming system includes a priming pump for developing a partial vacuum in the pumping chamber and causing liquid to be drawn into the pumping chamber to evacuate air therefrom. A sensor is provided for detecting the interface between the liquid and air in an area in or above the pumping chamber for activating and deactivating the priming pump. The sensor comprises a low sensitivity capacitive proximity sensor having a generally vertical sensing face for sensing the relative movement of the interface between the liquid and air.

Abstract: The invention relates to a self-cleaning filter in which the suspension to be filtered is introduced into the filter media at a lower portion of the apparatus. The dirtied filter media flows out the bottom of the apparatus by gravity, while the material being filtered flows upwardly through the filter media into an annular chamber, over a weir and out an outlet pipe. The dirty filter media is mixed with clarified liquid that is received from a confined chamber in the upper portion of the filtering apparatus and the slurry so formed flows into the inlet of a pump. The pump scours the material acting to partially separate the liquid and particulate from the filter material. The slurry is then pumped up into a separator wherein further separation takes place with the liquid and particulate matter being directed out of the separator back for reprocessing and the clean filter medium is reintroduced into the filtering apparatus.

Abstract: A grit selector having an upper settling chamber and a lower grit storage chamber. The settling chamber communicates with the grit storage chamber through an opening in a transition surface therebetween. An influent flume directs influent liquid directly into a lower portion of the settling chamber. An effluent flume withdraws effluent liquid from an upper portion of the settling chamber. The influent flume and effluent flume have a common centerline with the effluent flume being positioned at an elevation above the influent flume. A baffle member extends into the settling chamber for directing the influent liquid stream outwardly towards a lower portion of the periphery of the settling chamber.

Abstract: A sewage pumping station is disclosed which includes a sewage receiving wet well positioned adjacent to a machinery chamber which contains sewage pump means and associated controls. A base beam means, of hollow rectangular cross-section, is secured to the underside of the floor of the machinery chamber. The base beam means defines a suction pipe extension conduit in fluid communication with the wet well. Sewage pump means are supported above the floor of the machinery chamber by a substantially vertical suction conduit extending therebetween. The lower end of the suction conduit is in fluid communication with the suction extension conduit.A sump pump assembly is provided within the machinery chamber which directs accummulated liquid into the suction extension conduit. A control assembly is provided within the machinery chamber which senses the pressure within the suction extension conduit and controls the operation of the sewage pump means dependent upon the liquid level in the wet well.

Abstract: An improved multi-position plug valve is disclosed which greatly facilitates fluid flow control. In the preferred embodiment, the valve is adapted for connection with three individual pipes or conduits, and another main pipe or conduit. The valve includes a rotatable valve plug positioned within a valve body which can be selectively positioned for effecting fluid communication between any selected one or ones of the three individual pipes and the main pipe. The present valve is suited for use in a very wide variety of applications, and provides significant fabrication, installation and maintenance savings when compared with equivalent multi-valve systems heretofore required to provide equivalent flow control.

Abstract: A method and apparatus for removing oil from water. The invention includes a separation vessel for separating the oil by gravity from the water. The generally oil-free water from the separation vessel is pumped under pressure through an ultrafine molecular filter. The concentrate liquid from the ultrafine molecular filter is directed into a concentrator vessel which separates out the oil which remains in the concentrate liquid. The separated oil is directed back into the separation vessel and the remaining liquid is directed back through the ultrafine molecular filter. Ejection water is periodically directed into the separation vessel to discharge oil accumulated in the separation vessel.

Abstract: A sewage pumping or lift station is mounted on the upper edge of a standard concrete wet well. A vertical partition divides the station into a machinery chamber and an access chamber that are hermetically isolated from each other. The floor of the machinery chamber is imperforate except for a hole through which a sewage inlet pipe passes and that hole is sealed by weldments attaching the inlet pipe to the floor; this hermetically isolates the machinery chamber from the sewer gases in the wet well. Any other components which must communicate with the wet well pass through sealed holes in the vertical partition.