Abstract: A process and device for separating oil and volatile organic components from pressurized gases of a compression system in which, before oxidation-catalytic separation, a physical separation is performed to protect the oxidation-catalytic separator against a large amount of oil being entrained in a surge in the pressurized gases. The resulting oil which has been separated in this physical oil separation is then fed back into the pressurized gas flow which is flowing to oxidation-catalytic separation in metered amounts. This results in the oil concentration in the pressurized gas entering the oxidation-catalytic separation means being maintained such that oxidation-catalytic separation can be carried out effectively and under optimum operating conditions without there being an adverse effect on operation by oil concentrations which are suddenly high for an instant.

Abstract: An air box in a regenerative thermal oxidiser has one or several beds of a heat-storing and heat-transferring material. The air box is connected with a gas inlet/outlet and comprises a gas permeable surface that is turned towards one of the beds. The air box has distribution devices provided in the air box.

Abstract: An apparatus for contacting a bed of particulate material with a cross flowing fluid, which maintains the bed of particulate material within a retention volume. The apparatus includes partitions for retaining particles, with apertures disposed within the partitions. The apertures are covered by louvers that extend above the edges of the apertures to prevent solid particles from spilling through inlet apertures.

Abstract: Disclosed is an annular distributor having: an annular slit layer that is mounted on an inner circumferential surface of the annular distributor and has at least one slit discharging or introducing a fluid; at least one opening that is formed on an outer circumferential surface of the annular distributor and is connected with any one of a fluid supply duct and a fluid discharge duct; and at least one guide vane selected from three types of guide vanes that are installed in the annular distributor, and splits a flow rate of the fluid supplied from the duct or collects a flow rate of the fluid discharged to the duct. And disclosed are a reactor or heat exchanger has the annular distributor, and a method of producing unsaturated aldehyde or unsaturated acid from olefin by catalytic gas phase oxidation in the reactor.

Abstract: An autothermal reformer is provided for a fuel cell system utilizing one volume and a plurality of inlets for both start-up and normal operation. In start-up mode, thermal combustion is employed for heating the catalyst reformation section of the reformer. Two inlets are used to feed air and fuel into the system, which are mixed and ignited in the common volume. Once the catalyst has reached light-off temperature, a second set of inlets provide air, steam and fuel into the common volume. The mixture then passes into the catalytic reformation system.

Abstract: A safe, reduced pressure apparatus for generating water vapor from hydrogen and oxygen and feeding high purity moisture to processes such as semiconductor production. The apparatus eliminates the possibility of the gas igniting by maintaining the internal pressure of the catalytic reactor for generating moisture at a high level while supplying moisture gas from the reactor under reduced pressure. A heat dissipation reactor improvement substantially increases moisture generation without being an enlargement in size by efficient cooling of the reactor alumite-treated fins.

Abstract: Device for mixing and distributing a dense, generally liquid, fluid and a light, generally gaseous, fluid, placed in a reaction chamber upstream from a granular bed (70) or between two successive granular beds, the said device being characterized by a tubular system (50) for the introduction of dense fluid from outside the reactor, up to a level lower than the level of establishment of the interface between the dense fluid and the light fluid, situated above the plate and preferably more or less next to that of the plate (62). Application of this device to any type of gas/liquid reaction in a fixed bed in particular for hydrotreatment.

Abstract: Described herein is a microreactor for carrying out chemical reactions between a reaction partner in liquid form and a reaction partner in gaseous form, if necessary in the presence of a solid catalyst, whereby the chemical process guidance takes place in spaces that are formed by two or more essentially coplanar plates or layers, with at least one of these plates or layers being a fluid guidance plate (1) that is structured and/or arranged in such a way that the fluid reaction partner flows in at least one essentially uninterrupted capillary thread along the surface of this plate or layer only due to the influence of gravity and/or capillary forces and thereby comes into contact and reacts with the gaseous reaction partner.

Abstract: A catalytic converter and method for its assembly including an external shell formed in two halves containing a catalytic substrate, two internal shields and two-piece inlet and outlet cones. The inlet and outlet cones are attached as halves to each side of the external shell, and are assembled to each other as the external shells are assembled.

Abstract: A device located between two successive granular beds (203) and (205) for injecting a secondary fluid can produce and distribute a polyphase mixture between said secondary fluid and a fluid or mixture of fluids originating from the upper granular bed and comprises a chamber for injecting a secondary fluid (201), the secondary fluid being injected into said device, and means (204) for bringing said secondary fluid into contact with at least a portion of the fluid or mixture of fluids originating from the upper granular bed (203) and for simultaneous distribution (208) of the mixture resulting from said contact to the lower granular bed (205).

Abstract: A fluid flow inversion chamber comprises a spray nozzle (3) which has a coaxial configuration of feed flow (12) and steam flow (11) streams capable of providing increased contact of the two streams within the reaction zone, and, as a consequence of the inversion of the coaxial configuration of feed flow (12) and steam flow (11) streams, avoids the formation of coke, which facilitates inspection and replacement of nozzles worn by erosion.

Abstract: Replaceable outer support structure 38 for a particulate material bed 70 in a radial flow system comprises a plurality of hollow conduits 50, 250, 260, at least some of which have a generally trapezoidal cross-section. The conduits are arranged in a ring around the inside wall surface 39 of the vessel 42 and have flat or slightly concave inner wall surfaces 52 formed of segments of vertically extending screen members which have slots or openings 86 which provide uniform flow through the uniform thickness particulate bed which they help define The side walls 54, 56 of the conduits extend generally radially outwardly to engage the inner surface 39 of the outside wall 40 of the vessel and at least those of them which have a trapezoidal cross-section have their side walls formed at an included angle ? which is less than if they extended radially relative to the axis of the vessel.

Abstract: A cylindrical reactor containing a radial particle bed suitable for hydrocarbon reforming comprises: a reactor inlet (1) having a means of feeding a charge, numerous perforated, internal conduits (5) arranged around the periphery of the reactor and parallel to the axis of the reactor, which feed particle bed (2) with the charge, a circular collar (8) supporting the conduits in the lower bottom of the reactor, a perforated (7) central collector (3) receiving a reactor effluent connected to an outlet (14).

Abstract: A heater is disposed in contact with a hydrogen storage unit filled with a hydrogen absorption material. The heater includes at least one combustion chamber which includes a catalyst carrier and in which a combustible gas is burned, a combustible gas burning catalyst carried on the catalyst carrier, at least one combustible gas introduction chamber adjoining the combustion chamber with its chamber wall interposed therebetween, a plurality of combustible gas inlets disposed in a dispersed manner in the chamber wall to permit the combustion chamber and the introduction chamber to communicate with each other, and a combustion gas outlet communicating with the combustion chamber. Thus, the degree of uniformity of a temperature profile is decreased.

Abstract: An apparatus is disclosed for the generation of hydrogen peroxide. The apparatus provides for the production of a large scale volume of hydrogen peroxide by the generation of a liquid bearing bubble cloud. The bubbles are generated with a tiny volume before flowing over the reactor bed to generate the hydrogen peroxide.

Abstract: For mixing and distributing a gas phase and a liquid phase over a granular bed, employing an annular peripheral zone inside a reactor via which liquid is introduced and which acts as a buffer zone against fluctuations in the flow of the liquid phase. The device is applicable to catalytic bed chemical reactors especially for the hydrotreatment of hydrocarbons.

Abstract: An autothermal reformer according to the principles of the present invention comprises a first stage that selectively receives a fuel flow, a first oxidant flow, and a steam flow. The first stage has a first portion of a catalyst bed. The fluids within the first stage are routed through the first portion of the catalyst bed and react. There is a second stage downstream from and communicating with the first stage. The second stage receives the fluids from the first stage and also selectively receives a second oxidant flow. The second oxidant flow and the fluids received from the first stage flow through a second portion of a catalyst bed and further react.

Abstract: Carbonaceous material is removed from a catalyst within an autothermal reformer by introducing an isolated oxidant stream into the autothermal reformer prior to introduction of hydrocarbon fuel into the reformer. A hydrocarbon stream is introduced into the autothermal reformer following removal of the carbonaceous material. A concurrent supply of the hydrocarbon stream and the oxidant stream to the autothermal reformer is maintained such that an exothermic reaction driven by the oxidant stream provides heat to an endothermic reaction driven by water vapor in the hydrocarbon stream. In accordance with 37 CFR 1.72(b), the purpose of this abstract is to enable the United States Patent and Trademark Office and the public generally to determine quickly from a cursory inspection the nature and gist of the technical disclosure. The abstract will not be used for interpreting the scope of the claims.

Abstract: An up-flow reactor for the catalytic treatment of particle containing gas comprising at least one fixed catalytic bed; at least one drain pipe located upstream of the fixed catalytic bed, the drain pipe disposed within the reactor and a dust rectifier located downstream of the drain pipe and upstream of the fixed catalytic bed.

Abstract: In a method for catalytic oxidation of a gas, the outlay required is kept at a low level for reliably treating even relatively large quantities of gas and/or high concentrations of the gas fraction that needs to be treated. For this purpose, a gas stream including the gas being treated is circulated through a reaction zone and a return-flow zone, which is in communication with the inlet and outlet sides of the reaction zone. The circulation of the gas stream can be maintained effectively in the form of a passive system if the gas stream which includes the gas to be treated is guided in the upward direction in the reaction zone and the upward flow is assisted by convection resulting from the heat released during the oxidation reaction. Furthermore, the gas stream is preferably cooled locally in the return-flow zone by spray cooling.

Abstract: Described is an enclosed space, a column, or a reactor including a device for mixing and distribution of at least one gaseous phase and at least one liquid phase. The device can be placed upstream of a reaction zone or of a gas/liquid contact zone that can contain a packing bed or a bed of solid, possibly catalytic, particles. Also described is a process for implementing such an enclosed space, column or reactor and to a process for fabricating such an enclosed space, column or reactor.

Abstract: A compact quench box design for a multi-bed, mixed-phase cocurrent downflow fixed-bed reactor has a quench pipe manifold and nozzle assembly, a collection tray, a mixing chamber, and a single final distributor tray. The quench pipe manifold and nozzle assembly is an annular ring pipe having nozzles arising therefrom. The mixing chamber is an annular compartment depending from the collection tray above having a partition pan, forming a partition weir at its inside diameter for liquid to flow, and a bottom section pan, which forms a vapor outlet weir at its inside diameter for vapor flow onto the final distributor tray below. This design reduces the number of manway required for the quench box.

Abstract: Methods and apparatus for mixing a plurality of gases, preferably a fuel and an oxidant. The preferred embodiments are characterized by methods and apparatus for mixing at least a methane-containing gas and an oxygen-containing gas, preferably natural gas and molecular oxygen. The preferred embodiments of the present invention include a mixing section having a centrifugal mixer with a tangential inlet where the mixed gases are then injected at an angle into the reactor section. The oxidant and the fuel are mixed by the tangential motion of the fuel to form a reactant gas that then flows through a permeable mixing material that is also disposed within the chamber. The reactant gas injected at an angle into a reactor inlet chamber provides a substantially unobstructed path between the reactor and a pressure relief device.

Abstract: A thermally-integrated lower temperature water-gas shift reactor apparatus for converting carbon monoxide in the presence steam comprises a catalyst bed that is disposed within an outer region surrounding a waste heat recovery steam generator operating at a selected pressure corresponding to the optimum temperature for conducting the catalytic water-gas shift reaction and a process for useful recovery of the exothermic heat of reaction to generate steam that is used in a process for the conversion of hydrocarbon feedstock into useful gases such as hydrogen.

Abstract: A mixing system is disclosed which provides improved multiphase mixing through the use of a novel quench injection means. The mixing system comprises a horizontal collection tray, a mixing chamber positioned below the collection tray, and at least one passageway extending through the collection tray into the mixing chamber. The mixing chamber and the collection tray define a two-phase mixing volume. The passageway conducts fluid from above the collection tray into the mixing chamber. The mixing chamber preferably includes at least one outlet opening for the downward passage of fluid. In particular, mixing of quench fluid is significantly improved when quench is introduced into a region above the collection tray and where (i) lateral velocities of the process fluids are low, (ii) sufficient volume is available for the quench fluid to mix with the process fluids, and (iii) quench injection occurs opposite the prevailing direction of process fluid flow.

Abstract: A mixing system is disclosed which provides improved multiphase mixing through the use of a novel quench injection means. The mixing system comprises a horizontal collection tray, a mixing chamber positioned below the collection tray, and at least one passageway extending through the collection tray into the mixing chamber. The mixing chamber and the collection tray define a two-phase mixing volume. The passageway conducts fluid from above the collection tray into the mixing chamber. The mixing chamber preferably includes at least one outlet opening for the downward passage of fluid. In particular, mixing of quench fluid is significantly improved when quench is introduced into a region above the collection tray and where a preferred direction of quench injection is selected to cause a rotational current on the collection tray.

Abstract: The present invention comprises a mixing system that provides improved mixing of quench gas and process fluids in a height constrained interbed space while not increasing pressure drop. In particular, the device improves the effectiveness of an existing mixing volume in mixing the gas phase of two-phase systems. The mixing system includes a horizontal collection tray, a mixing chamber positioned below the collection tray, at least one passageway extending through the collection tray into the mixing chamber, and a vapor slipstream passageway extending through the collection tray into the mixing chamber for directing a vapor slipstream from above the collection tray into the mixing chamber. The mixing chamber and the collection tray define a two-phase mixing volume. The passageway conducts fluid containing at least some vapor from above the collection tray into the mixing chamber. The mixing chamber preferably includes at least one outlet opening for the downward passage of fluid.

Abstract: The present invention provides a novel means to provide more effective mixing of quench gas and process fluids in a height constrained interbed space of a catalytic reactor without increasing pressure drop. In particular, the device improves the effectiveness of an existing mixing volume in mixing the gas phase of two-phase systems. According to the present invention, the quench zone hardware contained within the reactor includes a substantially vertical continuous perimeter solid baffle attached to the underside of the collection tray.

Abstract: A device for distributing fluid into a monolith bed includes a plurality of flow channels stacked in order of decreasing diameter. The flow channels successively split a flow stream into a multiple flow streams prior to the flow stream entering the monolith bed.

Abstract: A reactor with a catalyst bed having a central longitudinal axis, which catalyst bed has an upstream surface perpendicular to the central longitudinal axis, and a distribution chamber for directing a gaseous mixture of reactants to the upstream surface of the catalyst bed, which distribution chamber has an inlet for tangentially introducing the mixture into the distribution chamber, the distribution chamber being defined by the upstream surface of the catalyst bed, a side surface having a central longitudinal axis that coincides with the central longitudinal axis of the catalyst bed, and a covering surface formed such that the distance between the upstream surface of the catalyst bed and the covering surface is monotonically decreasing towards the central longitudinal axis. The invention further relates to a fuel cell system having such a reactor and a fuel cell and to a process for the catalytic oxidation of a hydrocarbonaceous fuel using such a reactor.

Abstract: Described is a mixing device for mixing a gaseous stream of a fuel and an oxidant that has a cylindrical mixing chamber, means for injecting a gaseous stream of the fuel tangentially along the inner surface of the wall of the mixing chamber, and means for injecting a stream of the oxidant axially along the central longitudinal axis of the mixing chamber, wherein the diameter of the mixing chamber and the dimensions and location of the means for injecting the fuel and the oxidant are such that the tangentially injected stream of the fuel forms a wall jet around the axially injected stream of the oxidant without impinging upon the other stream. A reactor for the partial oxidation of a hydrocarbonaceous fuel containing the mixing device and to a process for the catalytic partial oxidation of a hydrocarbonaceous fuel using the mixing device is further described.

Abstract: A device feeds educts to parallel spaces separated from one another by way of a distributor unit. Outlets of the distributor unit are assigned to the spaces, and evaporator structures for the evaporation of liquid media are provided in the spaces. Each outlet of the distributor unit project into a space. The boiling point of the medium in the distributor unit is maintained above the temperature of the medium in the distributor unit.

Abstract: An axial/radial—or radial/flow catalytic reactor has inlet and outlet ports and a bed of particulate catalyst disposed as e.g. a cylinder or cone round a central region communicating with one of the ports. For at least part of the height of the catalyst bed, the exterior surface of the catalyst bed has a diameter less than that of the reactor thus leaving space between the exterior surface of the catalyst bed and the interior walls of the reactor. This space is filled with a particulate material presenting less resistance to flow than the catalyst particles.

Abstract: For use in a separation column, a mat element or a beam element has at least: an upper part 2; at least one distributor-collector part (3) having one or more secondary orifices (7i) and at least one main orifice (6), whereby the passage sections of orifices (8) and (7i) are different; and a lower part (4). The distributor-collector part or parts (3) arranged between the upper part (2) and the lower part (4). A sealing element (5a) arranged between the distributor-collector part (3) and the upper part (2), and a sealing element (5b) arranged between the distributor-collector part (3) and the lower part (4). A separation element (8) arranged at distributor-collector part (3), thus delimiting two spaces (3a, 3b) for circulation of fluids.

Abstract: The method for the reformation of fuels, in particular of heating oil (20?) and of another liquid fuel is carried out using an oxygen containing gas (5a, 5b, 21?, 22?). The method includes the following steps: formation of a fuel/gas mixture by dispersing of the fuel in a jet of the oxygen containing gas (21?); additionally an admixture of gas of a return flow (3b) and vaporization of the dispersed fuel; generation of synthesized gas from the gas mixture by means of partial oxidation and also reformation processes by heterogeneous catalysis; branching off of the produced synthesized gas into a product flow (3a) and the return flow (3b) for a recirculation; and a regulated extraction of heat from the return flow for the setting of a predetermined temperature of a catalyst support (10) on which the heterogeneous catalysis takes place.

Abstract: A method for extending the operating life of a fixed bed reactor for reacting a feedstock in which a feedstock is contacted with a fixed bed of catalytic material contained in the reactor.

Abstract: Methods and apparatus for treating a gas-liquid feed stream with structured monolithic catalysts of honeycomb configuration wherein the catalysts are configured as a stack of honeycomb sections with offset channels, the resulting channel dislocations between adjacent contacting honeycombs in the stack introducing controlled, limited turbulence and mixing of feed stream portions traversing the channels to significantly increase the catalytic efficiency of the reactor.

Abstract: A device for producing and distributing a polyphase mixture between two fluids comprises a chamber for the passage of a first fluid, said chamber being pierced by perforated tubes or conduits to pass a second fluid in a different physical state than the first fluid or not miscible with the first fluid through the chamber, said tubes being pierced by at least one orifice allowing passage of the first fluid and mixing between the fluids via the tubes. The second fluid is injected upstream of said device and the first fluid is injected into said device.

Abstract: A mixing system is disclosed which provides improved multiphase mixing through the use of a novel quench injection means. The mixing system comprises a horizontal collection tray, a mixing chamber positioned below the collection tray, and at least one passageway extending through the collection tray into the mixing chamber. The mixing chamber and the collection tray define a two-phase mixing volume. The passageway conducts fluid from above the collection tray into the mixing chamber. The mixing chamber preferably includes at least one outlet opening for the downward passage of fluid. In particular, mixing of quench fluid is significantly improved when quench is introduced into a region above the collection tray and where (i) lateral velocities of the process fluids are low, (ii) sufficient volume is available for the quench fluid to mix with the process fluids, and (iii) quench injection occurs opposite the prevailing direction of process fluid flow.

Abstract: A thermally diluted exothermic reactor system is comprised of numerous orifices distributed within a combustor by distributed perforated contactor tubes or ducts. The perforated contactors deliver and mix diluent fluid and one or more reactant fluids with an oxidant fluid. Numerous micro-jets about the perforated tubes deliver, mix and control the composition of reactant fluid, oxidant fluid and diluent fluid. The reactor controls one or more of composition profiles, composition ratio profiles and temperature profiles in one or more of the axial direction and one or two transverse directions, reduces temperature gradients and improves power, efficiency and emissions.

Abstract: A reactor module having one or more than one heat exchanger, a chamber block capable of being charged with a catalyst, and a platform are assembled in a unit in which separate fluid flows of reactants and heat media are directed by manifolds and ducts intrinsically formed in the module. Multiple reactor modules may be interconnected to form a further reactor module unit and the interconnected reactor units may in turn be configured for a large system with a high power rating.

Abstract: The present invention discloses a process and apparatus for improving the catalyst life and efficiency in a gas flow catalyst bed reactor assembly. The reactor comprises an outer reaction vessel, an inner displacement cylinder, and an annular catalyst bed surrounding the displacement cylinder having a top half and a bottom half. Fluid flow improvement is achieved by adding at least one baffle to the top half of the displacement cylinder to improve uniformity of fluid flow in the reaction vessel and across the catalyst bed. Also disclosed is a process for improving fluid flow uniformity in a gas phase reactor comprising an outer reaction vessel, an inner displacement vessel having a top half and a bottom half and a reaction outer surface and an inert inner space, and an annular catalyst bed. The process comprises conducting fluid flow simulations using actual reactor conditions. During simulation, baffles are added on the outer reaction surface of the displacement reactor to improve simulated fluid flow.

Abstract: A stack of very thin metal plates provides high surface area for catalytic decomposition of a fluid flowing axially from upstream to downstream through the stack. Each plate has flow-through passages of selected size and location to promote uniform flow and good surface contact with a catalyst surface on the plates. The downstream surface of each plate is etched to provide gaps between plates for lateral fluid flow. The plates are divided into groups separated by metering plates that promote more uniform flow from group to group.

Abstract: The device is arranged in a process engineering column (10) and serves in particular for the guiding of liquid. This device includes at least two parts (1, 2) made of sheet metal and releasably connected to one another. A recess (12) is arranged in the one part, the sheet metal part (1) of a first kind, and an elevation (21) fitting into the recess is arranged in the other part, the sheet metal part (2) of a second kind. The two sheet metal parts are held in a secured position by a hook connection between the recess and the elevation. The recess and the elevation form a single pair or one pair among several and the sheet metal parts have planar regions lying on top of one another in the neighbourhood (120, 210) of the pair or of each pair respectively.

Abstract: Device for mixing and distributing a dense, generally liquid, fluid and a light, generally gaseous, fluid, placed in a reaction chamber upstream from a granular bed (70) or between two successive granular beds, the said device being characterized by a tubular system (50) for the introduction of dense fluid from outside the reactor, up to a level lower than the level of establishment of the interface between the dense fluid and the light fluid, situated above the plate and preferably more or less next to that of the plate (62). Application of this device to any type of gas/liquid reaction in a fixed bed in particular for hydrotreatment.

Abstract: A fuel reformer having an enclosure with an inlet port and an outlet port. A plate assembly for supporting catalyst is disposed in the enclosure. A compliant baffle is also disposed in the enclosure and cooperates with the plate assembly to establish a path for the flow of fuel gas through the reformer from the inlet port to the outlet port. The baffle and plate assembly also segment the enclosure into an inlet section communicating with the inlet port, an outlet section communicating with the outlet port and a turn section connecting the inlet and outlet sections. The baffle is further arranged to direct the flow of gas to a predetermined area of the turn section and the catalyst is disposed such that the reformer is devoid of catalyst in the inlet section to a point in the turn section and includes catalyst from that point in the turn section through the return section, the catalyst varying in amount in a predetermined manner in at least the return section.

Abstract: A fluidized bed reactor (10) for chemically transforming reactants to generate a desired product, having a hollow, elongated, vertically oriented reactor housing (12) for confining the reaction and an unobstructed collection path (18) below the reaction zone for funneling the residue of the process to an exit port (32). A central gas inlet (22) proximate the bottom of the reaction zone within the housing directs gas parallel to the vertical axis of the housing to maintain the raw materials in suspension. A plurality of individually controlled peripheral gas jets (24) positioned at least two elevations along the elongated dimension of the reaction housing (12), and located circumferentially around the housing (12) at each elevation, introduce gas at an angle to promote mixing of the entrained materials in suspension. The clog-free collection path (18) below the reaction zone funnels the residue of the process to an exit port (32) where it is continuously removed by a screw feeder (34).

Abstract: An internal static mixing system such as a disperser of mesh wire or expanded metal co-knit with a multi filament material selected from inert polymers, catalytic polymers, catalytic metals or mixtures in combination with a vertical reactor having a reaction zone and the disperser disposed in said reaction zone, particularly for carrying out paraffin alkylation using acid catalyst is disclosed. The wire mesh provides the structural integrity of the system as well as the open space required in reactors for the movement of vapors and liquids though the system. The disperser may be in sheets, bundles or bales or positioned within a frame.

Abstract: A liquid distributor, for a substantially vertical reactor with a fixed bed catalyst, in the form of a channel distributor with drainage outlets and further comprising an internal cleaning mechanism with cleaning elements to be lowered into the openings of the drainage outlets, is disclosed.

Abstract: The invention relates to a mixing device (5) for mixing fluids in a multiple bed downflow reactor comprising: (i) a substantially horizontal collection tray (6); (ii) a swirl chamber (7) for mixing liquid arranged below the collection tray (6), having an upper end part that is in direct fluid communication with the upper surface (9) of the collection tray (6) and an outlet opening (10) at its lower end, wherein the swirl chamber (7) has a length that is at least 0.35 times its inner diameter; and (iii) a substantially horizontal distribution tray (13) located below the swirl chamber (7), which distribution tray (13) is provided with a plurality of openings or downcomers (14) for downward flow of liquid and gas. The invention further relates to a multiple bed downflow reactor comprising such a mixing device and to the use of such a reactor in hydrocarbon processing.