Abstract: The contacting device for countercurrent contacting of fluid streams and having a first pair of intersecting grids of spaced-apart and parallel deflector blades and a second pair of intersecting grids of spaced-apart and parallel deflector blades. The deflector blades in each one of the grids are interleaved with the deflector blades in the paired intersecting grid and may have uncut side portions that join them together along a transverse strip where the deflector blades cross each other or adjacent opposed ends of the deflector blades and cut side portions that extend from the uncut side portions to the ends of the deflector blades. At least some of the deflector blades have directional tabs and associated openings to allow portions of the fluid streams to pass through the deflector blades to facilitate mixing of the fluid streams.

Abstract: The present disclosure is directed towards improved systems and methods for large-scale production of nanoparticles used for delivery of therapeutic material. The apparatus can be used to manufacture a wide array of nanoparticles containing therapeutic material including, but not limited to, lipid nanoparticles and polymer nanoparticles. In certain embodiments, continuous flow operation and parallelization of microfluidic mixers contribute to increased nanoparticle production volume.

Abstract: The contacting device for countercurrent contacting of fluid streams and having a first pair of intersecting grids of spaced-apart and parallel deflector blades and a second pair of intersecting grids of spaced-apart and parallel deflector blades. The deflector blades in each one of the grids are interleaved with the deflector blades in the paired intersecting grid and may have uncut side portions that join them together along a transverse strip where the deflector blades cross each other or adjacent opposed ends of the deflector blades and cut side portions that extend from the uncut side portions to the ends of the deflector blades. At least some of the deflector blades have directional tabs and associated openings to allow portions of the fluid streams to pass through the deflector blades to facilitate mixing of the fluid streams.

Abstract: The contacting device for countercurrent contacting of fluid streams and having a first pair of intersecting grids of spaced-apart and parallel deflector blades and a second pair of intersecting grids of spaced-apart and parallel deflector blades. The deflector blades in each one of the grids are interleaved with the deflector blades in the paired intersecting grid and may have uncut side portions that join them together along a transverse strip where the deflector blades cross each other or adjacent opposed ends of the deflector blades and cut side portions that extend from the uncut side portions to the ends of the deflector blades. At least some of the deflector blades have directional tabs and associated openings to allow portions of the fluid streams to pass through the deflector blades to facilitate mixing of the fluid streams.

Abstract: The contacting device for countercurrent contacting of fluid streams and having a first pair of intersecting grids of spaced-apart and parallel deflector blades and a second pair of intersecting grids of spaced-apart and parallel deflector blades. The deflector blades in each one of the grids are interleaved with the deflector blades in the paired intersecting grid and may have uncut side portions that join them together along a transverse strip where the deflector blades cross each other and cut side portions that extend from the uncut side portions to the ends of the deflector blades. At least some of the deflector blades have directional tabs and associated openings to allow portions of the fluid streams to pass through the deflector blades to facilitate mixing of the fluid streams.

Abstract: This invention relates to a burner (1) for burning a suspension of solid fuel in oxygen containing gas. A portion of the suspension is passed through a first conduit (10) which contains a bluff body (12) and helical vanes to impart turbulence and swirl to the suspension. A further portion of the suspension is passed through a second conduit (40) which is coaxial with the first conduit. Means for varying the relative sizes of each portion are provided. The arrangement allows improved fuel/air mixing, flame shape, heat transfer and control of NOx emissions.

Abstract: A static mixer for mixing together at least two components includes a mixer housing, a mixing element arranged at least partly within the mixer housing, and a mixer inlet section having at least two inlets at an input side and at least two outlets at an output surface.

Abstract: A vortexing chamber, including: a chamber housing having a hollow channel, a first end and a second end; and one or more structural impediment objects having a substantially spherical, cubic, rectangular, cylindrical, polyhedron, tetrahedron, or irregular shape; where the objects are housed within the hollow channel, configured to mix a liquid and gas (for example, oxygen or nitrogen) when a liquid and gas pass through the vortexing chamber. The structural impediment objects can provide turbulence and dispersion when a liquid and gas are passed through the vortexing chamber at a high velocity, resulting in micro-bubbles or nano-bubbles suspended in a liquid and gas mixture.

Abstract: Systems are provided for a mixer. In one example, the mixer may include intersecting tubes with a plurality of inlets and/or outlets located along an exhaust conduit.

Abstract: A mixer assembly for a vehicle exhaust system includes a mixer having an upstream end and a downstream end. The mixer defines an internal cavity within which exhaust gases are mixed. A mixer inlet body has an enclosed end and an open end that attaches to the upstream end of the mixer. The mixer inlet body includes an outer peripheral surface extending from the enclosed end to the open end to surround a center axis. The outer peripheral surface includes an inlet port and the enclosed end includes a helically formed portion that initiates a swirling motion to the exhaust gases exiting the inlet port.

Abstract: An exhaust treatment arrangement includes a mixing assembly disposed between first and second substrates; and an injection mounting location disposed at the mixing assembly. The mixing assembly includes a mixing arrangement configured to direct exhaust flow exiting the first substrate in a swirling configuration, a restricting member defining a restricted passage, and optionally a dispersing member configured to even out the exhaust flow.

Abstract: Included is a method and system of generating a diffused fluid using a spiral mixer comprising: injecting a first fluid into a first inlet port, generating a first fluid ribbon using a first narrow-gap slot; injecting a second fluid into a second inlet port and generating a second fluid ribbon; combining the first fluid and the second fluid ribbon into a spiraling flow around a cone feature in the mixing chamber of the first spiral mixing block, generating a combined flow of diffused fluids; dividing the combined flow in the mixing chamber of the first flow divider block, generating a divided flow of diffused fluids; combining the divided flow a mixing chamber of the final spiral mixing block, generating a final combined fluid flow in a spiraling flow around a final cone feature; and flowing the final combined fluid flow and dispensing the combined fluid flow onto a substrate.

Abstract: A fluid control device for mixing liquids, includes at least: a monolithic base body; and a plurality of micro holes disposed in the base body. Also, the micro holes in a flow channel group ? that configures a specific group have opening portions in a region A and a region B on surfaces being outer surfaces of the base body, the micro holes in a flow channel group ? (n) that configures the other specific group have opening portions in the region A and a region C (n) on the surfaces being outer surfaces of the base body, and in the base body, the micro holes are disposed apart from the micro holes belonging to the different flow channel group throughout entire lengths. Here, the n refers to a natural number.

Abstract: A fluid mixing method using a micromixing apparatus which includes a mixing microchannel having a channel length and a continuously variable channel width defined by a first sidewall surface and an opposing second sidewall surface. The channel width varies from a minimum channel width h to a maximum channel width H in a ratio of H:h?1.1:1.0. A first inlet injects a first fluid and a second inlet a second fluid into the mixing microchannel which both flow in a flow direction in the mixing microchannel along the channel length. The first sidewall surface includes first curved surface portions and the second sidewall surface includes second curved surface portions. The first and second curved surface portions are non-overlapping to provide the variable channel width. The flow velocity profile is passively varied and exclusively controlled by the continuously variable channel width.

Abstract: The inventive subject matter provides apparatus, systems and methods for treating a fuel prior to ignition in a combustion engine in order to improve efficiency. In one aspect of the invention a throttle valve system that entrains a flow of gas, which can include a fuel, into a structured flow pattern via the inclusion of topological on a surface of the valve body and/or the flow chamber. The topological features can be arranged in a pattern configured to produce movement and/or structured turbulence in a stream of gas that is introduced to the throttle valve. An excitation source that ionizes or cracks species in the gas stream can be optionally utilized.

Abstract: Provided are a fluid agitation apparatus using a structure which is simple in shape and short in a fluid passage direction without a movable part so as to produce a sufficient effect from the viewpoint of reducing temperature fluctuation, and a thermostatic apparatus using the fluid agitation apparatus. The fluid agitation apparatus is installed in a fluid passage and includes, in an order from an upstream side thereof: a dividing part for dividing a flow of a fluid into a plurality of flows; a circumvolving part for circumvolving the fluid about an axis in a flow direction of the fluid; and an accelerating part for increasing a flow rate of the fluid.

Abstract: An inner premix tube for a fuel injector of a gas turbine engine includes a transition end, a tip end, and a premix tube inner surface. The transition end includes an annular disk portion with an annular disk shape and a redirection portion extending radially inward and axially from the annular disk portion. The transition end also includes a plurality of wipe passages extending through the transition end. The tip end includes a cylindrical portion with a hollow right circular cylinder shape. The premix tube inner surface is a radially outer surface including the redirection portion outer surface and the cylindrical portion outer surface.

Abstract: The invention provides a mixing system comprising the following: A) at least one extensional flow mixer comprising: a generally open and hollow body having a contoured outer surface and having: a single entrance port and a single exit port; a design for compressing a bulk stream, and a design for broadening the bulk stream and the at least one injected additive stream; B) a flow conductor; and C) a primary additive stream injector, as described herein; and wherein the extensional flow mixer is followed by D) a first helical static mixing element that is at least one half “flow conductor diameter (D1)” downstream of the exit port of the extensional flow mixer; and wherein the mixing system comprises at least four helical static mixing elements, placed such that the leading edge of the first helical static mixing element is located perpendicular to the main axis (major axis) of the exit port of the extensional flow mixer.

Abstract: A fluid mixer includes a main flow path comprised of a first flow path and a second flow path, spiral flow paths formed around the second flow path in shapes substantially concentric with the second flow path and offset in position from each other in a circumferential direction, the spiral flow paths having first ends communicated with the first flow path, branch flow paths branched from a plurality of locations of the second flow path in a flow direction, the branch flow paths being communicated with the spiral flow paths at a plurality of locations of the spiral flow paths in the flow direction, a fluid inlet at an open end of either of the first flow path and the second flow path, and a fluid outlet at an open end of the other of the first flow path and the second flow path.

Abstract: The system and method for preventing air leakage from the process side to the bearing side of a mill. The system includes a labyrinth seal ring comprising a series of knives defining first and second labyrinth paths from an air inlet to the process side and the bearing side of the system, respectively. The differences in the two paths such as provided by the number of knives used in each path creates a differential pressure drop which biases air from the air inlet to the process side. The labyrinth seal thus provides a reliable and superior method for reducing the potential for particulate in the process side of the mill from damaging the bearing system.

Abstract: An apparatus for the mixing conveying of fluids with heat exchange includes a housing with installations that each include a first hollow structure for conveying a first fluid while a second fluid is able to flow around the first hollow structure. The second fluid flows along a main flow direction which is substantially disposed along the longitudinal axis of the housing. A second hollow structure is provided through which the first fluid can flow and which can be flowed around by the second fluid with the second hollow structure being arranged cross-wise with respect to the first hollow structure. The hollow structures have a flow cross-section with a first width B1 and a second width B2, with B1/B2 being larger than one and B1 oriented normally to a plane which contains the longitudinal axis of the housing or a line parallel to the longitudinal axis and an axis of the hollow structure.

Abstract: In an exhaust gas pipe, a first fluid flows in a flow direction in the pipe, and a second fluid is injected inside the pipe by a nozzle, from an injection inlet arranged in the pipe wall, according to an injection direction. A mixing device fastened inside the pipe upstream from the injection inlet creates turbulence that helps the mixing of the fluids. The mixing device has a first portion located on the injection inlet side of the pipe and a second portion located opposite the injection inlet side of the pipe, the portions being designed so that the fluid velocity is higher downstream from the mixing device second portion than downstream from the mixing device first portion. An aqueous solution of urea can be injected inside an exhaust pipe of a diesel engine.

Abstract: A beverage container for mixing a beverage is disclosed. The beverage container includes a cup having a stirring flap integral to an internal side wall of the cup. The stifling flap has a sine wave shape and comprises a top fin protruding near the top of the internal wall and a bottom fin protruding near the bottom of the internal wall of the cup. The top fin and the bottom fin are separated by a central portion. The cup is swirled in a circular motion by a person's hand to mix the liquid contained within. The central portion allows liquid to pass freely through the middle of the cup to gain momentum when the cup is swirled. The bottom fin has the shape of a lower case letter ‘h’, to allow solid material gathered in the bottom of the cup to pass underneath the bottom fin and mix with liquid.

Abstract: A static mixing device that uniquely utilizes fluid shear, turbulence and impingement in a compact package to mix fluids, in particular liquids, entering the inlet of the device. The static mixing device enables a reduction in dead volume and/or pressure drop when compared to prior art static mixers.

Abstract: The current disclosure relates to a new fluid composite, a device for producing the fluid composite, and a method of production therewith, and more specifically a fluid composite made of a fuel and its oxidant for burning as part of different systems such as fuel burners, where the fluid composite after a stage of intense molecular between a controlled flow of a liquid such as fuel and a faster flow of compressed highly directional gas such as air results in the creation of a three dimensional matrix of small hallow spheres each made of a layer of fuel around a volume of pressurized gas. In an alternate embodiment, external conditions such as inline pressure warps the spherical cells into a network of oblong shape cells where pressurized air is used as part of the combustion process. In yet another embodiment, additional gas such as air is added via a second inlet to increase the proportion of oxidant to carburant as part of the mixture.

Abstract: Scalable compact static mixer comprising a rotationally symmetrical cascaded mixing structure.

Abstract: A baffle includes a body member having a first surface, a second opposed surface, and an outer peripheral edge. An aperture may be formed through the body member so as to define an inner peripheral edge. The inner peripheral edge is distorted so as to be non-planar. An apparatus includes a first conduit having a first end, a second end, and a first channel extending therebetween. At least one baffle is disposed in the first channel and includes a body member having a first surface, a second opposed surface, and an outer peripheral edge. At least one aperture may be formed through the body member to define an inner peripheral edge. The inner peripheral edge is distorted so as to be non-planar. A second conduit may be disposed inside the first conduit and extend through the aperture in the baffle. The apparatus may, for example, be configured as an ultraviolet light reactor, a heat exchanger, or a static mixer.

Abstract: The static mixer (1) includes at least one vane pair (2; 2a, 2b) for the generation of a flow swirl (300) in the direction (30) of a passage flow (3). Edges of the vanes at the front at the leading side are perpendicular to the passage flow and parallel to a height of the passage (10). Onflow surfaces following downstream are bent out in a concave manner and in opposite senses. Each vane (2a, 2b) is formed as an aerodynamically designed body which includes an end wall (20), a convex side wall (21) and a concave side wall (22). The end wall has a convex shape or a shape of a leading edge. The vane cross-sections perpendicular to the side walls in particular have similar shapes to cross-sections of aeroplane wings.

Abstract: A fluidic device, the fluidic device comprising a planar fluidic conduit for conducting a fluid, wherein the fluidic conduit has a plurality of fluidic disturbance features located along at least a section of the fluidic conduit for disturbing a laminar flow of the fluid along the section.

Abstract: A vane inlet apparatus is provided for separating components of a feed stream. The apparatus includes a body having an axis, a proximal end, and a distal end. The body includes an inlet and a plurality of vanes disposed along the axis. Each vane includes an aperture such that the apertures in successive vanes decrease in size toward the distal end of the apparatus. The vanes may be flat or curved. The sizes, shaped, and orientation of the vanes along the apparatus may be determined according to the designed specifications of a particular project. The apparatus as well as the vanes and apertures are preferably cylindrically shaped to match the incoming feed stream cross-section. A method of constructing the vane inlet apparatus is also provided.

Abstract: The invention relates to a system and to a method for controlling an aircraft engine starter-generator. The system comprises a transmission box (20) with a fixed gear ratio intended to be mechanically coupled to a turbine shaft (12) of the engine to allow the latter to be started, a gearbox (40) with multiple gear ratios that is mechanically coupled to a pinion of the transmission box, a starter-generator (30) mechanically coupled to a pinion of the gearbox, and means for instigating a change in gear ratio of the gearbox according to the mode of operation of the starter-generator.

Abstract: A static mixer may include a conduit section having a channel, an injector opening through an inner wall thereof, a tab having a main portion extending from the inner wall adjacent and downstream of the opening and extending radially inwardly at an angle away from the opening in the downstream direction, and having at least one finger extending at a non-zero angle from the main portion, the main portion and the at least one finger being configured such that a second fluid injected through the injector opening and into a first fluid flowing through the conduit section flows radially along the main portion toward a center of the conduit section, and radially outward from the main portion along the at least one finger, whereby the first and second fluids are thoroughly mixed as a result of turbulence imparted by the tab to the fluids.

Abstract: An exhaust treatment system includes an exhaust conduit for conveying exhaust gases from an engine of a vehicle. An aftertreatment device is disposed in the exhaust conduit. A flow device is disposed upstream of the aftertreatment device. The flow device includes a base having a first surface and an oppositely disposed second surface. The base defines a plurality of openings. A plurality of flow deflectors is engaged to the base at the plurality of openings. Each flow deflector includes a first deflector that extends outwardly from the first surface of the base and a second deflector that extends outwardly from the second surface of the base. The first and second deflectors define a passage. Flow of exhaust gases through the passage cause exhaust gases to swirl about a longitudinal axis of the exhaust conduit.

Abstract: A process for the continuous production of a compound of Formula (II), HO—R1—ONO2 (II) wherein R1 is a straight chain alkyl radical having from 3 to 6 carbon atoms, in a two-phase solvent system, comprising contacting a compound of Formula (I), HO—R1—OH (I) wherein R1 is as defined above, with nitric acid in the presence of a first solvent, wherein the compound of Formula (II) is continuously extracted into a second solvent, and the reaction is carried out in a mixing microreactor which provides a power loss of at least 1.3 times the power loss provided under identical conditions by a circular cross-section straight-channel microreactor having an internal diameter equal to the average hydraulic diameter of the mixing microreactor and a length equal to the length of the mixing microreactor.

Abstract: A fluid mixing method using a micromixing apparatus which includes a mixing microchannel having a channel length and a continuously variable channel width defined by a first sidewall surface and an opposing second sidewall surface. The channel width varies from a minimum channel width h to a maximum channel width H in a ratio of H:h?1.1:1.0. A first inlet injects a first fluid and a second inlet a second fluid into the mixing microchannel which both flow in a flow direction in the mixing microchannel along the channel length. The first sidewall surface includes first curved surface portions and the second sidewall surface includes second curved surface portions. The first and second curved surface portions are non-overlapping to provide the variable channel width. The flow velocity profile is passively varied and exclusively controlled by the continuously variable channel width.

Abstract: A mixer for mixing an exhaust flow with a fluid injected into an exhaust pipe includes a first mixing element including a base interconnecting first and second sidewalls and a deflection element positioned to be impacted by the injected fluid as well as a mixing fin positioned downstream of the deflection element. A second mixing element includes first and second spaced apart mounting flanges fixed to inner surfaces of the first and second sidewalls. Alternately, the mixer includes first and second mixing elements positioned within circumferentially spaced apart slots axially extending from an open end of a tubular housing.

Abstract: A gas delivery pipe for transmitting a gas, the pipe comprising: a wall defining a lumen of the pipe; an inlet aperture through which gas flows into the pipe; an outlet aperture through which gas flows out of the pipe; wherein the pipe has an index, SI, characterizing a degree to which the pipe is serpentine that is equal to an integral of an absolute value of changes in angle of direction that a unit vector tangent to a midline of the lumen undergoes in moving along the midline from the inlet to the outlet aperture, which integral has a value greater than or about equal to 180°.

Abstract: Devices and methods for mixing a clotting agent with other inputs such as blood, blood derived product, bone marrow, and/or bone marrow derived product to form a congealed mixture.

Abstract: Flow deflector that is capable of changing the flow direction of a fluid during passage through a duct. The duct is formed by an inner and outer duct, which creates an annular region in the duct. The flow deflector forces the fluid passing through the annular region of the duct to flow inside the inner duct, while the fluid passing through the inner duct is forced to flow through the annular region. Reactor tubes for catalytic reactors are formed by assembling tubes comprising said flow deflector and having a catalyst arranged in the inner tube.

Abstract: A mixing device for a fuel reformer for mixing at least two fluids is provided. The mixing device includes at least a first plurality of holes which is arranged along a first row, and a second plurality of holes which is arranged along a second row. The mixing device can be used in a fuel reformer for converting hydrocarbon fuel into hydrogen rich gas by auto-thermal reaction process having a, preferably cylindrically shaped and double walled, housing with two side walls forming a reaction chamber of the fuel reformer, wherein hydrocarbon fuel and an oxidizing agent are mixed by the mixing device.

Abstract: A baffle includes a body member having a first surface, a second opposed surface, and an outer peripheral edge. An aperture may be formed through the body member to define an inner peripheral edge. The inner peripheral edge is distorted to be non-planar. An apparatus includes a first conduit having a first end, a second end, and a first channel extending therebetween. At least one baffle is disposed in the first channel and includes a body member having a first surface, a second opposed surface, and an outer peripheral edge. At least one aperture may be formed through the body member to define an inner peripheral edge. The inner peripheral edge is distorted to be non-planar. A second conduit may be disposed inside the first conduit and extend through the aperture in the baffle. The apparatus may be an ultraviolet light reactor, a heat exchanger, or a static mixer.

Abstract: AVClip recorded in BD-ROM is obtained by multiplexing a graphics stream and a video stream. The graphics stream is a PES packet sequence that includes 1) PES packets storing graphics data (ODS) and 2) PES packets storing control information (PCS). In each ODS, values of DTS and PTS indicate a timing of decoding start for corresponding graphics data, and a timing of decoding end for corresponding graphics data, respectively. In each PCS, a value of PTS indicates a display timing of corresponding decoded graphics data combined with the video stream.

Abstract: A carrier fluid and an added input fluid are mixed together in a static mixer to create an emulsified output fluid mixture. The static mixer comprises a plurality of mixing chambers whose cross-sectional size expand considerably relative to an inlet, a series of bent and curved baffle plates which divert, rotate, divide, reverse and otherwise create turbulence in the combined flow, and inlet chamber in which the added input fluid is dispensed upstream into the carrier fluid, and a number of other structural mixing elements which, through turbulence, abrupt pressure drops and velocity changes, subdivide the added input mixture into very small volumetric quantities evenly dispersed within the carrier fluid to create a homogeneous output fluid mixture.

Abstract: A polymer composition containing two kinds of polymers and having a difference in its glass transition temperature of 3° C. or lower between before and after heat-treatment by getting it through a space between two parallel faces in a molten state.

Abstract: A static conditioner for mounting within a tubular conduit in turn supporting fluid flow therein and including a two-stage construction having a first stage including primary vanes including laterally extending caps radially inwardly extending into the fluid flow so as to separate and direct flow against the conduit walls and a second stage of secondary plates positioned immediately downstream of the first stage and laterally offset therefrom so as to eliminate swirl and turbulence remaining in the flow after the first stage.

Abstract: A planar labyrinth micromixer is disclosed that includes an inlet port, a plurality of curved channels, a plurality of abrupt turns, and an outlet port. The inlet port is for receiving a plurality of input fluids to be mixed. The plurality of curved channels induce transverse Dean vortices that rotate processing streams. The plurality of abrupt turns fold laminar flow of the processing streams, shift elliptical points corresponding to centers of Dean flow regions, and disrupt flow islands. The output port is for providing the processing streams as a mixture of the plurality of input fluids.

Abstract: A combined flow straightener and mixer is disclosed as well as a burner for a combustion chamber of a gas turbine having such a mixing device. At least two streamlined bodies are arranged in a structure comprising the side walls of the mixer. The leading edge area of each streamlined body has a profile, which is oriented parallel to a main flow direction prevailing at the leading edge position, and with reference to a central plane of the streamlined bodies, the trailing edges are provided with at least two lobes in opposite transverse directions. The periodic deflections forming the lobes from two adjacent streamlined bodies are out of phase.

Abstract: An apparatus and method for mixing gas streams of different temperatures and/or compositions contemplates that at least one of the streams contains particle. The apparatus includes a main duct for the first gas stream and a plurality of duct assemblies extending in the main duct generally transversely to the first gas stream. Each assembly has plural inlets and outlets for receiving and discharging separate parts of the second gas stream, moving initially generally transverse to the first stream. The assemblies each have plural secondary ducts of mutually different lengths from inlet to outlet, the outlets being spaced from each other across the main duct for distributing the parts of the second gas stream into the first gas stream. A gas flow deflector is connected to each duct assembly for temporarily deflecting the first gas stream before it is combined with the parts of the second gas stream.

Abstract: An array of airfoil-shaped micro-mixers that enhances fluid mixing within permeable membrane channels, such as used in reverse-osmosis filtration units, while minimizing additional pressure drop. The enhanced mixing reduces fouling of the membrane surfaces. The airfoil-shaped micro-mixer can also be coated with or comprised of biofouling-resistant (biocidal/germicidal) ingredients.

Abstract: A method and an apparatus are described for use in the irradiation of fluids. The apparatus has an elongate conduit (312) having a central axis (334) and two or more elongate ultraviolet radiation sources (114) extending along the interior of the conduit for irradiation of the fluid within the conduit. An array of static mixer elements (300) is located within the conduit, and the two or more elongate ultraviolet radiation sources (114) are arranged to extend through apertures in deflection surfaces of the static mixer elements making up the array (300). The apparatus and method allows for reliable and uniform ultraviolet irradiation of fluids of low UV transmissivity, such as turbid fluids, particularly for ultraviolet disinfection of such fluids. Wipers may be fitted to the static mixer elements to enable relative movement between the static mixer elements and the surfaces of the elongate ultraviolet radiation sources to clean the surfaces of the sources without need to dismantle the apparatus.