Abstract: A grit removal system with an annular grit removal chamber and a central hopper beneath the chamber bottom, including an opening through the chamber bottom to the hopper. Influent and effluent channels direct wastewater with grit into and out of the grit removal chamber. A plate over the chamber bottom opening has a first portion with a plurality of first openings therethrough and a second plate portion with a plurality of second openings therethrough, wherein the flow velocity for a given flow rate through the first openings is greater than the flow velocity for the given flow rate through the second openings.

Abstract: A pumping system including a pumping chamber with a fluid sensor having a cylindrical shaft extending into the priming chamber. The sensor has a sensing dome on an end of a cylindrical shaft extending into the priming chamber, with the dome having a vertical base having a diameter less than the cylindrical shaft diameter. The sensor signals a controller whether liquid is present based on an algorithm with settings for dampening of the electromagnetic field, conductance of the electric field, and/or permittivity of the magnetic field using settings which correlate to the fluid environment. The controller controls operation of the pump and primer based on the sensor signal.

Abstract: A grit removal unit including a cylindrical grit removal chamber above a grit storage chamber, with an opening to the grit storage chamber through the grit removal chamber bottom. At least one layer plate is an inverted truncated cone around the center axis which is spaced from the grit removal chamber vertical wall to allow fluid flow therebetween. Concentric inverted truncated cone lamella plates are supported in the grit removal chamber above the layered plates, with the lamella plates radially spaced from one another relative to the center axis. An influent opening in the grit removal chamber vertical wall below the layered plates allows fluid and grit into the grit removal chamber, and an effluent opening in the grit removal chamber vertical wall above the lamella plates allows fluid to exit the grit removal chamber.

Abstract: A grit removal unit including a cylindrical grit removal chamber above a grit storage chamber, with an opening to the grit storage chamber through the grit removal chamber bottom. At least one layer plate is an inverted truncated cone around the center axis which is spaced from the grit removal chamber vertical wall to allow fluid flow therebetween. Concentric inverted truncated cone lamella plates are supported in the grit removal chamber above the layered plates, with the lamella plates radially spaced from one another relative to the center axis. An influent opening in the grit removal chamber vertical wall below the layered plates allows fluid and grit into the grit removal chamber, and an effluent opening in the grit removal chamber vertical wall above the lamella plates allows fluid to exit the grit removal chamber.

Abstract: A grit removal unit for a wastewater system including a grit removal chamber with a substantially annular vertical wall. A horizontal annular ring above the chamber bottom extends inwardly from the annular vertical wall, with an influent channel extending into the chamber beneath the ring and an effluent channel above the rim and extending out of the chamber. The influent and effluent channels both have inner side walls with a curved portion, with both curved portions extending through an arc of at least 90 degrees within the chamber annular vertical wall.

Abstract: A grit removal unit for a wastewater system including a grit removal chamber with a substantially annular vertical wall. A horizontal annular ring above the chamber bottom extends inwardly from the annular vertical wall, with an influent channel extending into the chamber beneath the ring and an effluent channel above the rim and extending out of the chamber. The influent and effluent channels both have inner side walls with a curved portion, with both curved portions extending through an arc of at least 90 degrees within the chamber annular vertical wall.

Abstract: A grit removal unit for a wastewater system including a grit removal chamber with a substantially annular vertical wall. A horizontal annular ring above the chamber bottom extends inwardly from the annular vertical wall, with an influent channel extending into the chamber beneath the ring and an effluent channel above the rim and extending out of the chamber. The influent and effluent channels both have inner side walls with a curved portion, with both curved portions extending through an arc of at least 90 degrees within the chamber annular vertical wall.

Abstract: A pumping unit and method controlling a variable speed pump to output constant flow rate against varying outlet pressure using a controller with stored data curves of flow rate versus discharge pressure for a plurality of pump speeds for the variable speed pump, including a processor determining appropriate pump speed for the sensed discharge outlet pressure by extrapolating between the stored data curves.

Abstract: A grit removal unit including an influent channel directing wastewater with grit into a round grit removal chamber and an effluent channel receives wastewater output from the chamber. A divider wall extends upwardly between the sides of the influent channel, and gates at the upstream end of the divider wall are adjustable to selectively open channel portions on opposite sides of the divider wall. An output guide member is mounted to allow selective adjustment of output flow opening width “c” to the effluent channel. The output guide member has a horizontal bottom extending from the chamber into the effluent channel across the width of the output opening, and a guide wall extending upwardly from the guide member bottom. The guide wall has a forward end spaced from the chamber annular vertical wall to define the output flow opening width therebetween.

Abstract: A grit removal unit including an influent channel directing wastewater with grit into a round grit removal chamber and an effluent channel receives wastewater output from the chamber. A divider wall extends upwardly between the sides of the influent channel, and gates at the upstream end of the divider wall are adjustable to selectively open channel portions on opposite sides of the divider wall. An output guide member is mounted to allow selective adjustment of output flow opening width “c” to the effluent channel. The output guide member has a horizontal bottom extending from the chamber into the effluent channel across the width of the output opening, and a guide wall extending upwardly from the guide member bottom. The guide wall has a forward end spaced from the chamber annular vertical wall to define the output flow opening width therebetween.

Abstract: A grit removal unit including an influent channel directing wastewater with grit into a round grit removal chamber and an effluent channel receives wastewater output from the chamber. A divider wall extends upwardly between the sides of the influent channel, and gates at the upstream end of the divider wall are adjustable to selectively open channel portions on opposite sides of the divider wall. An output guide member is mounted to allow selective adjustment of output flow opening width “c” to the effluent channel. The output guide member has a horizontal bottom extending from the chamber into the effluent channel across the width of the output opening, and a guide wall extending upwardly from the guide member bottom. The guide wall has a forward end spaced from the chamber annular vertical wall to define the output flow opening width therebetween.

Abstract: A pumping unit and method controlling a variable speed pump to output constant flow rate against varying outlet pressure using a controller with stored data curves of flow rate versus discharge pressure for a plurality of pump speeds for the variable speed pump, including a processor determining appropriate pump speed for the sensed discharge outlet pressure by extrapolating between the stored data curves.

Abstract: A grit removal unit for a wastewater system including a grit removal chamber with a substantially annular vertical wall. A horizontal annular ring above the chamber bottom extends inwardly from the annular vertical wall, with an influent channel extending into the chamber beneath the ring and an effluent channel above the rim and extending out of the chamber. The influent and effluent channels both have inner side walls with a curved portion, with both curved portions extending through an arc of at least 90 degrees within the chamber annular vertical wall.

Abstract: A grit removal unit including an influent channel directing wastewater with grit into a round grit removal chamber and an effluent channel receives wastewater output from the chamber. A divider wall extends upwardly between the sides of the influent channel, and gates at the upstream end of the divider wall are adjustable to selectively open channel portions on opposite sides of the divider wall. An output guide member is mounted to allow selective adjustment of output flow opening width “c” to the effluent channel. The output guide member has a horizontal bottom extending from the chamber into the effluent channel across the width of the output opening, and a guide wall extending upwardly from the guide member bottom. The guide wall has a forward end spaced from the chamber annular vertical wall to define the output flow opening width therebetween.

Abstract: An input channel (and method of making an input channel) for the flow of waste water into a grit removal unit. The input channel has a depth D extending from the bottom to the top of the channel. One side wall of the channel is configured to vary the channel width over the depth of the channel, whereby (a) the width at the bottom of the channel is WB, (b) the width at the top of the channel is WT, and (c) the width at channel depth “d” above the bottom of the channel is Wd, wherein (i) 0?d?D, (ii) WB<WT, and (iii) Wd is greater than or equal to the channel widths at substantially every channel depth less than “d”. The channel profile may be integral to the channel, or defined by a separately added component, and selectively be stepped, tapered and/or curved.

Abstract: An input channel (and method of making an input channel) for the flow of waste water into a grit removal unit. The input channel has a depth D extending from the bottom to the top of the channel. One side wall of the channel is configured to vary the channel width over the depth of the channel, whereby (a) the width at the bottom of the channel is WB, (b) the width at the top of the channel is WT, and (c) the width at channel depth “d” above the bottom of the channel is Wd, wherein (i) 0?d?D, (ii) WB<WT, and (iii) Wd is greater than or equal to the channel widths at substantially every channel depth less than “d”. The channel profile may be integral to the channel, or defined by a separately added component, and selectively be stepped, tapered and/or curved.

Abstract: An apparatus for introducing gas into a large body of liquid, including a horizontal frame on ballast adjustable floats, a pressurized gas source, a vertical shaft rotatable about its axis, and a plurality of blades submerged in the liquid and extending radially from a hub on the lower end of the shaft. The blades each have an elastomeric membrane around a longitudinal member, where the longitudinal member is hollow with a closed end and in communication with the pressurized gas source through the shaft on the other end, with openings through its lower side, and the elastomeric membrane has perforations which are spaced from the longitudinal member openings. A drive on the platform rotates the shaft via a ring gear around the shaft with a key connection thereto allowing axial movement therethrough, and an inwardly facing surface supported on bearings. A selectively driven and smaller pinion gear directly engages the ring gear.