Waveguide or flow guide surfaces can improve the efficiency of fluid flow through tubes or over surfaces. When incorporated in a tube, the waveguides improve flow and function as sound absorbers making them useful in engine mufflers, firearm silencer/suppressors and jet engine exhaust attenuators. On surfaces, the waveguides can reduce fluid drag and find use on projectiles (e.g., bullets), airfoils for aircraft, and land borne vehicles. The waveguide array in either a tubular chamber or on a surface comprises a plurality of successive wave-like undulations inclined generally in the direction of flow and when employed in tubes extending inwardly to permit an unobstructed path for the fluid gas from entry to exit. The waves define annular wave cavities between their successive inwardly extending edges and the wall of the chamber with each cavity having a cavity mouth open to the unobstructed path. The waveguides are sized and spaced so that gas vortices are created within the cavities when gas flow occurs which vortices create a fluid boundary layer that assists the gas flow.

A mobile water re-use system can include a chemical treatment apparatus, at least one weir tank in fluid communication with the chemical treatment apparatus, and two or more settling tanks in fluid communication with each other and at least one of the settling tanks in fluid communication with the weir tank. The weir tank can have a first end, a second end, an internal chamber, and a plurality of baffles that induce turbulent flow of fluid through the internal chamber. The settling tanks can provide, promote, facilitate, result in, and/or induce laminar flow of fluid through at least a portion of the internal chamber. Weir tanks, settling tanks, and method of treating flowback and produced water are also described.

A method of treating flowback and produced water includes transferring flowback and produced water to a chemical treatment apparatus, mixing treatment chemicals with the flowback and produced water, transferring the mixture of treatment chemicals and flowback and produced water to a weir tank comprising a first end, a second end, an internal chamber, and a plurality of baffles positioned throughout the internal chamber to induce turbulent flow, transferring the mixture of treatment chemicals and flowback and produced water to a first settling tank that provides laminar flow, and transferring the mixture of treatment chemicals and flowback and produced water to a second settling tank that provides laminar flow.

A vortex-controlled variable flow resistance device ideal for use in a backpressure tool for advancing drill string in extended reach downhole operations. The characteristics of the pressure waves generated by the device are controlled by the growth and decay of vortices in the vortex chamber(s) of a flow path. The flow path includes a switch, such as a bi-stable fluidic switch, for reversing the direction of the flow in the vortex chamber. The flow path may include multiple vortex chambers, and the device may include multiple flow paths. A hardened insert in the outlet of the vortex chamber resists erosion. This device generates backpressures of short duration and slower frequencies approaching the resonant frequency of the drill string, which maximizes axial motion in the drill sting and weight on the bit. Additionally, fluid pulses produced by the tool enhance debris removal ahead of the bit.

A method of treating flowback and produced water includes transferring flowback and produced water to a chemical treatment apparatus, mixing treatment chemicals with the flowback and produced water, transferring the mixture of treatment chemicals and flowback and produced water to a weir tank comprising a first end, a second end, an internal chamber, and a plurality of baffles positioned throughout the internal chamber to induce turbulent flow, transferring the mixture of treatment chemicals and flowback and produced water to a first settling tank that provides laminar flow, and transferring the mixture of treatment chemicals and flowback and produced water to a second settling tank that provides laminar flow.

A mobile water re-use system can include a chemical treatment apparatus, at least one weir tank in fluid communication with the chemical treatment apparatus, and two or more settling tanks in fluid communication with each other and at least one of the settling tanks in fluid communication with the weir tank. The weir tank can have a first end, a second end, an internal chamber, and a plurality of baffles that induce turbulent flow of fluid through the internal chamber. The settling tanks can provide, promote, facilitate, result in, and/or induce laminar flow of fluid through at least a portion of the internal chamber. Weir tanks, settling tanks, and method of treating flowback and produced water are also described.

A mobile water re-use system can include a chemical treatment apparatus, at least one weir tank in fluid communication with the chemical treatment apparatus, and two or more settling tanks in fluid communication with each other and at least one of the settling tanks in fluid communication with the weir tank. The weir tank can have a first end, a second end, an internal chamber, and a plurality of baffles that induce turbulent flow of fluid through the internal chamber. The settling tanks can provide, promote, facilitate, result in, and/or induce laminar flow of fluid through at least a portion of the internal chamber. Weir tanks, settling tanks, and method of treating flowback and produced water are also described.

An injector mixer arrangement (10) for supplying a reducing agent in gaseous form into a flue gas flowing in a gas duct (14) communicating with a catalyst (18a) in a selective catalytic reduction (SCR) reactor (12) arranged downstream of said injector mixer arrangement (10). The injector mixer arrangement (10) comprises an injector grid (22) equipped with a plurality of nozzles (30) arranged horizontally within the gas duct (14). The nozzles (30) are adapted to supply said reducing agent to the gas duct (14). The injector mixer arrangement (10) further comprises first stage mixer plates (24) and second stage mixer plates (26) arranged in the gas duct (14) downstream of said nozzles (30) and upstream of SCR reactor 12.

A vortex-controlled variable flow resistance device ideal for use in a backpressure tool for advancing drill string in extended reach downhole operations. The characteristics of the pressure waves generated by the device are controlled by the growth and decay of vortices in the vortex chamber(s) of a flow path. The flow path includes a switch, such as a bi-stable fluidic switch, for reversing the direction of the flow in the vortex chamber. The flow path may include multiple vortex chambers, and the device may include multiple flow paths. A hardened insert in the outlet of the vortex chamber resists erosion. This device generates backpressures of short duration and slower frequencies approaching the resonant frequency of the drill string, which maximizes axial motion in the drill sting and weight on the bit. Additionally, fluid pulses produced by the tool enhance debris removal ahead of the bit.