WO2002089965A1

WO2002089965A1 - Method and static mixer for mixing at least two fluids

Info

Publication number: WO2002089965A1
Application number: PCT/EP2002/004906
Authority: WO
Inventors: Holger LÖWE; Volker Hessel; Steffen Hardt
Original assignee: INSTITUT FüR MIKROTECHNIK MAINZ GMBH
Priority date: 2001-05-07
Filing date: 2002-05-04
Publication date: 2002-11-14
Also published as: DE10123092B4; DE10123092A1

Abstract

The invention relates to a method for mixing at least two fluids, according to which a plurality of separate fluid streams of both fluids converge, forming fluid lamellae of alternately adjacent fluids. The convergent fluid lamellae are evacuated in the form of a focalised combined fluid stream. Said focalised combined fluid stream is introduced as a jet of fluid into a swirl chamber, forming a fluid spiral that flows towards the interior. The mixture formed is drained from the centre of the fluid spiral. The micro-mixer is characterised by a swirl chamber (6, 16, 116), into which the focalising channel (5, 15, 35, 45, 105, 105', 115, 115') opens in such a way that the focalised combined fluid stream enters in the form of a jet of fluid and forms a fluid spiral (100) that flows towards the interior. At least one outlet channel (7) that has a fluidic connection to the swirl chamber (6, 16, 116) drains the mixture that has been formed.

Description

Method and static mixer for mixing at least two fluids

description

The invention relates to a method for mixing at least two fluids according to claim 1 and a static micromixer according to the preamble of claim 12.

The aim when mixing at least two fluids is to achieve a uniform division of the two fluids in a determined, usually as short a time as possible. Static micromixers are particularly advantageously used for this purpose, as shown in the overview by W. Ehrfeld, V. Hessel, H. Löwe in Microreactors, New Technology for Modern Chemistry, Wiley-NCH 2000, pages 41 to 85. For mixing liquids, known static micromixers achieve mixing times between 1 s and a few milliseconds by generating alternately adjacent fluid lamellae with a thickness in the μm range. The mixing of gases takes place much faster due to the higher diffusion constants. In contrast to dynamic mixers, in which turbulent flow conditions prevail, the specified geometry in static micromixers enables the width of the fluid lamella and thus the diffusion paths to be set precisely. The very narrow distribution of the mixing times achieved in static micromixers in this way allows a wide range of possibilities for optimizing chemical reactions with regard to selectivity and yield. Another advantage of static micromixers is the reduction in component size and thus the ability to be integrated into other systems such as heat exchangers and reactors. The interaction of two or more components interconnected in such a small space in turn opens up new possibilities for process optimization. The application potential of micromixers extends from liquid-liquid and gas-gas mixtures to form liquid-liquid emulsions, gas-liquid dispersions and thus also to multi-phase and phase transfer reactions.

A static micromixer working according to the principle of multilamination has a microstructured interdigital structure consisting of interlocking channels with a width of 25 μm or 40 μm in one plane (see above, pages 64 to 73). The two fluids to be mixed are divided by the channels into a multiplicity of separate fluid streams which flow in opposite directions and are arranged in alternation with one another. The adjacent fluid flows are discharged vertically upwards out of the plane through a slot and contacted with one another. Using structuring processes suitable for mass production, the channel geometries and thus the fluid lamella width can only be reduced to a limited extent down to the lower μm range.

A further reduction in the fluid lamellae obtained according to the multilamination principle can be achieved by so-called geometric focusing. Such a static micromixer for converting dangerous substances is described by TM Floyd et al. on pages 171 to 179 in Microreaction technology: industrial prospects; proceedings of the Third International Conference on Microreaction Technology / IMRET3, editor: W. Ehrfeld, Springer 2000. Alternating adjacent channels for the two fluids to be mixed open in a semicircle radially from the outside into a funnel-shaped chamber that merges into a narrow, long channel. The fluid lamella flow combined in the chamber is hereby transferred into the narrow channel, as a result of which the fluid lamella width is reduced. Under these laminar flow conditions Mixing takes place solely by diffusion, so that mixing times in the millisecond range can also be achieved by reducing the lamella widths in the lower μm range. It is disadvantageous that the narrow channel serving as the reaction space has to be designed with sufficient length with regard to complete mixing, which requires a large design and causes a relatively high pressure loss in this micromixer.

The object of the invention is to provide a method and a static micromixer for mixing at least two fluids, which enable faster and more uniform mixing with at the same time low pressure loss and small installation space.

The object is achieved according to the invention with a method according to claim 1 and a static micromixer according to claim 12.

In the following, the term fluid is understood to mean a gaseous or liquid substance or a mixture of such substances, which can contain one or more solid, liquid or gaseous substances, dissolved or dispersed.

The term mixing also includes the processes of dissolving, dispersing and emulsifying. Accordingly, the term mixture includes solutions, liquid-liquid emulsions, gas-liquid and solid-liquid dispersions.

A plurality of fluid flows, fluid lamellae or fluid channels are understood to mean two or more, preferably three or more, particularly preferably five or more, fluid flows, fluid lamellae or fluid channels per fluid. Alternating adjacent fluid lamellae or fluid channels means that two fluids A, B alternate in at least one plane, resulting in an order of ABAB, side by side. The term "alternately adjacent" includes three fluids A, B, C different Sequences such as ABCABC or ABACABAC. The fluid lamellae or fluid channels can also be alternately adjacent in more than one plane, for example in two dimensions in a checkerboard manner. The fluid lamellae and fluid channels belonging to the different fluids are preferably arranged in the same direction or in the opposite direction parallel to one another. The last-mentioned variant of the flow arrangement is known in principle from microstructured interdigital structures from interlocking fluid channels. The two fluids to be mixed are divided by the fluid channels into a multiplicity of separate fluid lamellae, which flow in opposite directions and flow alternately to one another.

The process according to the invention for mixing at least two fluids comprises at least four process steps. In the first step, a large number of separate fluid flows of the two fluids are brought together, with alternating adjacent fluid lamellae of the two fluids being formed. In the second step, the fluid lamellae thus combined are discharged to form a focused total fluid flow. In the third step, the total fluid flow obtained in this way is introduced as a fluid jet into a swirl chamber with the formation of an inward flowing fluid spiral. In the last process step, the mixture formed in this way is derived from the center of the fluid spiral.

The merging takes place in such a way that the initially separate fluid flows flow into a room. In this case, the fluid streams can be aligned parallel to one another or leading into one another, for example radially inwards. When merging, fluid lamellae form, the cross-sectional areas of which initially correspond to those of the fluid streams. The removal as a focused total fluid flow results in a reduction in the width and / or the cross-sectional area of the fluid lamellae, while at the same time increasing the flow rate. The focused total fluid flow accelerated in this way is introduced as a fluid jet into the swirl chamber. The in the fluid jet entering the swirl chamber flows along a spiral line inwards to the center of the swirl chamber, where the mixture is discharged. Due to the previous focusing, the fluid flow has correspondingly alternating fluid lamellae.

Only the fluid flowing in the outermost turn adjoins the lateral inner surfaces of the swirl chamber; the inner turns of the fluid spiral border on both sides to the fluid flowing in the same direction of the previous and the subsequent turn. Therefore, only the contact with the upper and lower inner surface of the swirl chamber essentially contributes to the friction. The pressure loss achieved with this mixer is therefore less than that with a mixer with a correspondingly long focusing channel. In addition, the spiral shape ensures a compact design with a long mixing section and thus a long dwell time.

Another advantage is the contact of one turn of the fluid spiral with the previous and the following turn, which contributes to the faster diffusive mixing of the fluid lamellae with one another.

Laminar flow conditions advantageously prevail inside the swirl chamber. However, it is also conceivable to have turbulent flow conditions in partial areas with an overall fluid flow flowing spirally.

With regard to a complete mixing by diffusion, the fluid flow flowing spirally inward has a sufficient length and thus a sufficient number of turns in order to achieve a sufficient dwell time for each fluid volume flowing into the swirl chamber. The setting of the desired ratios can in particular be achieved by a corresponding choice of the cross-sectional area of the inflowing focused total fluid flow, the shape and dimensions of the swirl chamber and the cross-sectional area of the outlet for the mixture formed from the swirl chamber.

Fluid streams each having a width in the range from 1 μm to 1 mm and a depth in the range from 10 μm to 10 mm are preferably combined.

The combined fluid flows are preferably focused in such a way that the ratio of the cross-sectional area of the focused total fluid flow to the sum of the cross-sectional areas of the fluid flows to be combined is perpendicular to the flow direction in the range from 1 to 1.5 to 1 to 500, preferably in the range from 1 to 2 to 1 to 50. The smaller the ratio, the more the lamella width is reduced and the more the flow speed is increased, with which the focused total fluid flow is introduced as a fluid jet into the swirl chamber. According to one embodiment variant, the focused total fluid flow has a cross section that is constant over its length. According to another embodiment variant, the cross-sectional area of the focused total fluid flow decreases from the area where the fluid flows are brought together to the point where it flows into the swirl chamber, the above relationship being valid for the area with the smallest cross-sectional area.

The ratio of the length of the focused total fluid flow to its width is preferably in the range from 1 to 1 to 30 to 1, preferably in the range from 1.5 to 1 to 10 to 1. Here, the focused total fluid flow should be as long as possible to ensure a sufficiently focused one Force effect while maintaining the laminar flow conditions. However, the focused total fluid flow should be made short with a view to a low pressure drop and a compact design to be able to introduce the total fluid flow as quickly as possible into the swirl chamber as a fluid jet.

The vortex chamber advantageously has a substantially round or oval shape in the plane of the fluid spiral in order to enable the fluid spiral to be formed in the case of laminar flow conditions and low pressure loss.

According to one embodiment, the focused total fluid flow is introduced into the swirl chamber at an acute angle or preferably tangentially, in particular in order to generate as many turns of the fluid spiral as possible and to cover dead water areas, i.e. H. Avoid areas that are not constantly flowed through.

When contacting immiscible fluids (e.g. liquid-gaseous), it can be advantageous to let the disperse phase flow into the vortex chamber at a steeper angle than the continuous phase. An adjacent tangential inflow of the continuous phase can shear off the resulting drops or bubbles, which results in smaller drops / bubbles. Since in the case of the mixing of liquid and gaseous fluids the liquid has a substantially higher mass than the gas, the spiral formation is only slightly disturbed by the introduction of the gases at a steeper angle.

It may be advantageous to introduce a further fluid into the combined fluid flows and / or into the swirl chamber. The further fluid can have an auxiliary substance stabilizing the mixture, for example an emulsifier. It is also conceivable that the fluid streams already contain such an additive. According to a preferred embodiment, the first two process steps are carried out simultaneously at at least two spatially separated locations and the focused total fluid flows thus obtained are introduced in one plane of the swirl chamber in such a way that a common inward flowing fluid spiral is formed, which is formed from at least two individual fluid spirals lying one inside the other becomes. The fluid spirals that are formed lie together in one plane and around a center in such a way that the respective turns lie adjacent to one another. For example, with two or three focused total fluid streams introduced, a kind of double or triple spiral results.

In a further preferred embodiment, the first two method steps are carried out simultaneously at at least two spatially separate locations, and the focused total fluid flows thus obtained are fed to the swirl chamber in different planes in such a way that fluid spirals which flow one above the other form.

For example, it is possible to introduce one or more focused total gas flows and total liquid flows alternately adjacent to the swirl chamber on a first level and to introduce further total liquid flows into the swirl chamber in the subsequent levels. This can be achieved, for example, by increasing the height of the swirl chamber, with the outlet on the floor and the inlet near the ceiling of the swirl chamber, for example, so that a vertical movement is superimposed on the plane fluid movement. Helical trajectories are obtained instead of spiral trajectories. In this way, for example, the residence time and contact time of gas bubbles in or with a liquid phase can be increased. If further total fluid flows are introduced into the swirl chamber in the further downward levels, these form fewer turns until they are discharged from the swirl chamber. By this embodiment is achieved by the lengthening of the fluid flow and the higher number of turns of the fluid spiral which forms an even greater residence time of the total fluid flows in the swirl chamber.

The focused total fluid flows are introduced into the vortex chamber symmetrically in one or more planes, particularly advantageously. The total fluid flows to be introduced can have the same fluids or also different fluids, which are then only contacted and mixed in the common space. The different versions described above can also be used advantageously in this embodiment.

In a further embodiment, the focused total fluid flows are introduced into the swirl chamber at different angles. This embodiment is used particularly advantageously for mixing gases with liquids in the swirl chamber. The total gas flows are introduced into the swirl chamber at a steeper angle than the total liquid flows, the total liquid flows also being able to have gas-liquid dispersions. As a result, the total gas flows flowing into the swirl chamber are broken down into small gas bubbles by the total liquid flows.

The static micromixer according to the invention for mixing at least two fluids is characterized by a swirl chamber, into which the focusing channel opens in such a way that the focused total fluid flow enters as a fluid jet with the formation of an inwardly flowing fluid spiral, and at least one outlet channel that is fluidly connected to the swirl chamber for discharge the mixture formed. The plurality of alternately adjacent fluid channels preferably have a width in the range from 1 μm to 1 mm and a depth in the range from 10 μm to 10 mm for the separate supply of the fluids as fluid streams.

The inlet chamber, into which the fluid channels open, serves to bring together the plurality of separate fluid streams of the two fluids. The focusing channel is fluidly connected to the inlet chamber for discharging the fluid streams combined in the egg chamber to form a focused total fluid stream. The focusing channel opens into the vertebrae in such a way that the focused total fluid flow enters as a fluid jet, forming a fluid spiral flowing concentrically inwards. The at least one outlet channel, which is in fluid communication with the swirl chamber, serves to discharge the mixture formed.

With regard to the advantages associated with this micromixer, reference is made to the above explanations of the method according to the invention, in particular to a low pressure drop, increase in the contact area available for the faster diffusive mixture and small design.

The rapid mixing is achieved by producing very thin fluid lamellae and thus by reducing the diffusion path. The fluid lamellae are fed to the swirl chamber, which causes a further reduction in the diffusion path by tilting the fluid lamellae and reducing the lamella width. The swirl chamber can be designed relatively large-scale (large diameter, high height), but very thin fins are still produced. The pressure loss in the swirl chamber can be kept low due to the large hydraulic diameter. Only the constriction through the focusing channel contributes to the pressure loss. This constriction can, however, take place very locally, ie over a very small flow length, so that there is only a moderate pressure loss. The inlet manifold preferably has a concave wall opposite the fluid channels, into which the focusing channel advantageously opens in the center.

Due to the concave wall, a rapid merging is combined with a focusing and discharge into the focusing channel while maintaining the fluid lamellae.

However, it is also conceivable to gradually feed the combined fluid lamellae onto the focusing channel, for which purpose the inlet chamber is triangular-shaped or funnel-shaped in at least one plane in the direction of flow.

According to a further embodiment, the inlet chamber has a cross section which is constant in the flow direction. Focusing then does not take place in the inlet channel, but only in the focusing channel, which can have, for example, a tapering cross section in the flow direction. In this case, the cross section of the inlet opening of the focusing channel will preferably correspond to the cross section of the inlet chamber.

The focusing channel can also have a constant cross section in the direction of flow, which is used in particular when the inlet chamber already ensures focusing, so that the focusing in the focusing channel is only continued.

Two preferred embodiments of how the fluid channels open into the inlet chamber are an orientation parallel to one another and an orientation tapering radially in the direction of the inlet chamber. In terms of a simple technical implementation, it is advantageous if the fluid channels, the egg chamber, the focusing channel and / or the swirl chamber have the same depth. It is also advantageous here if the openings of the fluid channels lie at least in one plane in the region of the inlet chamber.

The focusing channel is preferably designed in such a way that the ratio of the cross-sectional area of the focusing channel to the sum of the cross-sectional areas of the fluid channels opening into the inlet manifold is perpendicular to the channel axis in the range from 1 to 1.5 to 1 to 500, preferably in the range from 1 to 2 to 1 in 50. As a result, a further reduction in the lamella width and / or cross-sectional area and, as a result, an increase in the flow velocity is achieved in comparison with the predetermined width of the fluid channels. According to one embodiment variant, the focusing channel has an essentially constant cross section over its entire length.

According to another embodiment variant, the cross-sectional area of the focusing channel decreases from the inlet chamber to the swirl chamber, the above ratio of the cross-sectional areas being used for the area with the smallest cross-sectional area. The cross-sectional area of the focusing channel in the region of the confluence with the swirl chamber also determines the width and thus the number of turns of the spirally wound fluid flow. The ratio of the width of the focusing channel opening into the swirl chamber to the diameter of the swirl chamber in the plane in which the fluid spiral is formed is advantageously less than or equal to 1 to 10.

The ratio of the length of the focusing channel to its width is preferably in the range from 1 to 1 to 30 to 1, preferably in the range from 1.5 to 1 to 10 to 1, at least in the region where it flows into the swirl chamber. Here, the length of the focusing channel is advantageously chosen so that focusing on small fluid lamella widths while maintaining the fluid lamellae and in the sense of a low pressure loss is rapidly introduced into the swirl chamber.

In a preferred embodiment, the focusing channel is arranged at an acute angle or tangential into the vertebrae. This allows, in particular, the introduction of the fluid lamella flow while maintaining laminar flow conditions and the formation of a fluid spiral with a large number of turns.

The vortex chamber preferably has a substantially round or oval cross section in a plane in which the focusing channel lies. Dead water areas are thereby avoided. The vortex chamber particularly preferably has an essentially cylindrical shape. The height of the focusing channel, at least in the region of the junction, is advantageously less than or equal to the height of the swirl chamber.

The outlet channel or channels preferably open into the swirl chamber below and / or above a central region, in particular in the region of the center. The cross-sectional area of the outlet channel or channels is advantageously dimensioned in comparison to the diameter of the swirl chamber and the cross-sectional area of the opening focusing channel so that a fluid spiral with a large number of turns can form. The ratio of the diameter of the outlet channel to the diameter of the swirl chamber is preferably less than or equal to 1 to 5.

According to a further embodiment, one or more feed channels for feeding a further fluid open into the inlet chamber, the focusing channel or the swirl chamber. Such fluids can be an auxiliary substance stabilizing the mixture, for example one Emulsifier. Advantageously, the feed channels lead tangentially into the swirl chamber, so that a stream of the further fluid lies between adjacent turns of the fluid spiral. When a gaseous, further fluid is fed into a fluid spiral containing at least one liquid in the swirl chamber, the feed channels for the further fluid do not open particularly tangentially, but rather at a steeper angle into the swirl chamber. In this way, the supplied gas is divided into small gas bubbles by the fluid spiral and finely distributed.

According to a further embodiment, the plurality of adjacent fluid channels, the inlet chamber, into which the fluid channels open, and the focusing channel, which is fluidly connected to the inlet chamber, are each provided two or more times, and the two or more focusing channels open into a common swirl chamber in one plane , The focusing channels open into the swirl chamber at an acute angle or preferably tangentially in such a way that the fluid jets correspondingly form two or more fluid spirals flowing concentrically inward adjacent to one another. The focusing channels are advantageously arranged in a plane equidistant from the common vortex chamber. The two or more multiplicity of adjacent fluid channels, inlet chambers and focusing channels are spatially separated from one another and are only fluidly connected to one another via the common swirl chamber. These structures can be used to supply the same fluids, for example twice the fluids A, B, or else different fluids, for example the fluids A, B and C, D.

In a further preferred embodiment, the plurality of adjacent fluid channels, the inlet chamber into which the fluid channels open, and the focusing channel fluidically connected to the inlet chamber are each provided two or more times and the two or more Focusing channels open into a common vortex chamber on several levels.

In a further advantageous embodiment, the focusing channels for the total fluid flows open into the swirl chamber at different angles. This embodiment is used in particular for the mixing of focused total gas streams with total fluid streams which contain at least one liquid in the swirl chamber. In this case, the feed channels for the total gas streams open into the swirl chamber at an acute angle than the feed channels for the total fluid streams containing at least one liquid. In this way, the total gas flows introduced at a steep angle are broken down into fine gas bubbles by the total liquid flows introduced at an acute angle.

According to a further preferred embodiment, the fluid guide structures are introduced as recesses and / or openings in plates made of a material which is sufficiently inert for the fluids to be mixed. Recesses, such as grooves or blind holes, are surrounded by material in one plane and perpendicular to it. Breakthroughs such as slits or holes, on the other hand, pass through the material, i.e. are only laterally surrounded by the material in one plane. The open structures of the recesses and breakthroughs become, by stacking with further plates, fluid guide structures, such as fluid channels and chambers, the cover and / or bottom plates, which seal the plate stack in a fluid-tight manner to the outside, supplying the two fluids and / or at least one discharge for the formed Have mixture.

In a variant of this embodiment, the structures of the fluid channels, the inlet manifold, the focusing channel and the swirl chamber are as recesses and / or openings in at least one as a mixer plate serving plate introduced. The open structures of the mixer plate are closed off by a cover and base plate which are connected in a fluid-tight manner to the mixer plate.

According to a further variant of this preferred embodiment, the static micromixer has, between the mixer plate and the base plate, a distributor plate, which is connected to them in a fluid-tight manner, for separately supplying the fluids from the feeds in the base plate to the fluid channels of the mixer plate. For this purpose, the distributor plate advantageously has a number of holes for each fluid to be supplied, each hole being assigned to exactly one fluid channel. In the case of two fluids, the first row serves to supply the first fluid and the second row serves to supply the second fluid.

Suitable materials are, depending on the fluids used, different materials, such as polymer materials, metals, alloys, glasses, quartz glass, ceramics or semiconductor materials, such as silicon. Preference is given to plates with a thickness of 10 μm to 5 mm, particularly preferably from 50 μm to 1 mm. Suitable methods for the fluid-tight connection of the plates to one another are, for example, pressing together, using seals, adhesive bonding or anodic bonding.

Known precision engineering and microtechnical manufacturing processes are possible as processes for structuring the plates, such as, for example, laser ablation, spark erosion, injection molding, embossing or galvanic deposition. LIGA processes are also suitable, which include at least the steps of structuring with high-energy radiation and galvanic deposition and, if necessary, molding. The method according to the invention and the static micromixer are advantageously used to carry out chemical reactions of two or more substances, both substances being contained in an introduced fluid or the first substance being contained in a first fluid and the second substance being contained in a further fluid. For this purpose, means for controlling the chemical conversion are advantageously integrated in the static micromixer, such as temperature or pressure sensors, flow meters, heating elements, indwelling tubes or heat exchangers. In the case of a static micromixer, these means can be arranged on plates with the fluid guide structures or further plates arranged above and / or below and functionally connected to them. To carry out heterogeneously catalyzed chemical reactions, the material of the static micromixer can also have catalytic material.

The method according to the invention and the micromixer according to the invention are used particularly advantageously for producing a gas-liquid dispersion, with at least one introduced total fluid stream being a gas or a gas mixture and at least one further introduced total fluid stream being a liquid, a liquid mixture, a solution, a dispersion or contains an emulsion.

Exemplary embodiments of the static micromixer according to the invention are explained below using the drawings as examples. Show it

Figure 1 a a static micromixer consisting of a

Cover plate, mixer plate, distributor plate and base plate each separated from one another in a perspective view,

1b shows a preferred mixer plate according to FIG.

FIG. 2 shows another preferred mixer plate in a top view, FIG. 3 shows another preferred mixer plate in top view,

FIG. 4 shows another preferred top view,

5 shows a partial section through a static micromixer according to a further embodiment.

FIG. 1 a shows a static micromixer 1 with a cover plate 21, a mixer plate 20, a distributor plate 26 and a base plate 22, each separated from one another in a perspective view.

The cover plate 21, the mixer plate 20, the distributor plate 26 and the base plate 22 each have a feed 23, 23 ', 23 "for the fluid A and a feed 24, 24', 24" for the fluid B in the form of a bore. The bores are arranged in such a way that when the plates are stacked one above the other, the feeds 23, 23 ', 23 ", 24, 24', 24" are in fluid communication with the feed structures 23 '", 24'" of the base plate 22. The feed 23 '"for the fluid A and the feed 24'" for the fluid B are arranged in the form of grooves 123 a, b, 124a, b on the base plate 22 in such a way that the fluid A to the distributor structure 27 and the fluid B can be routed to the distributor structure 28 of the distributor plate 26 lying above it without significant pressure losses. Connecting grooves 123a, 124a lead from the feed structures 23 '", 24'" to distributor grooves 123b, 124b, the connecting groove 124b expanding in a funnel shape. The manifold plate 26 has a manifold structure 27 for the fluid A and a manifold structure 28 for the fluid B each in the form of a series of holes passing through the plate, which lie above the manifold grooves 123b and 124b. The mixer plate 20 shown in FIG. 1b in plan view has fluid channels 2, 3, an inlet chamber 4, a focusing channel 5 and a swirl chamber 6. The discharge 25 in the form of a bore in the cover plate 21 is arranged such that when the plates are stacked one above the other the discharge 25 is in fluid communication with a central region of the swirl chamber 6 of the mixer plate 20. The channels 2 for the fluid A have a smaller length than the channels 3 for the fluid B. The channels 2, 3 are oriented parallel to one another in their side facing away from the inlet chamber 4, the channels 2 for the fluid A alternately lying adjacent to the channels 3 for the fluid B. In a transition area, the distance between the channels decreases in the direction of the inlet chamber 4. In the area of the opening into the inlet chamber 4, the channels 2, 3 are in turn aligned parallel to one another. In order to achieve a uniform volume flow over all channels 2, 3 for one fluid each, the channels 2, 3 each have the same length among themselves. The result of this is that the ends of the fluid channels 2, 3, which are remote from the inlet chamber 4, each lie on an arc. The bores of the distributor structures 27, 28 of the distributor plate 26 are also each arranged in an arc in such a way that the ends of the channels 2, 3 are each contacted fluidically with a bore. The inlet chamber 4, into which the fluid channels 2, 3 open, has a concave shape in the plane of the fluid channels. In the central region of the concave wall 8, which lies opposite the openings of the fluid channels 2, 3, the inlet chamber 4 merges into the focusing channel 5. The focusing channel 5 opens tangentially into the swirl chamber 6, which is formed by a chamber which is circular in the plane of the mixer plate 20. The structures of the fluid channels 2, 3, the inlet chamber 4, the focusing channel 5 and the swirl chamber 6 are formed through openings through the material of the mixer plate 20, as a result of which these structures have the same depth. The underlying distribution plate 26 and the overlying cover plate 21 cover these structures, which are open on two sides, to form channels or chambers. In the ready-to-use micromixer 1, the plates 21, 20, 26 and 22 shown here separately from one another are stacked one above the other and fluidly connected to one another, as a result of which the open structures, such as grooves 23 '", 24'" and openings 2, 3, 4, 5 and 6, covered with formation of channels and chambers. The stack of plates 21, 20, 26 and 22 thus obtained can be accommodated in a mixer housing which has suitable fluid connections for the supply of two fluids and the discharge of the fluid mixture. In addition, the housing can be used to apply a contact pressure to the plate stack for fluid-tight connection. It is also conceivable to operate the plate stack as a micro-mixer 1 without a housing, for which purpose fluidic connections, for example hose nozzles, are advantageously connected to the inlets 23, 24 and the outlet 25 of the cover plate 21.

During the actual mixing process, a fluid A and a fluid B are introduced into the feed bore 23 and into the feed bore 24 of the cover plate 21. These fluids each flow through the feed structures 23 ', 23 ", 23'" and 24 ', 24 ", 24'" of the plates 20, 26 and 22 and from there are evenly distributed into the distributor structures 27 and 28 designed as bores. From the bores of the distributor structure 27, the fluid A flows into the channels 2 of the mixer plate 20 arranged exactly above it. Likewise, the fluid B arrives from the bores of the distributor structure 28 into the channels 3 arranged exactly above it A, B are brought together in the intake manifold 4 to form alternately adjacent fluid lamellae of the sequence ABAB. Due to the semi-concave shape of the inlet chamber 4, the combined fluid flows are quickly transferred into the focusing channel 5. The focused total fluid flow thus formed is introduced tangentially into the swirl chamber 6 as a fluid jet. A fluid spiral 100 flowing concentrically inwards is formed in the swirl chamber 6. The mixture of fluids A, B formed is formed by the above the center of the Vortex chamber 6 located drain hole 25 of the cover plate 21 derived.

FIG. 2 shows a mixer plate 20 with three focusing channels 5, 15, 35 opening into a common swirl chamber 16 in plan view. The focusing channels 5, 15, 35 are each in fluid communication with an inlet chamber 4, 14, 34 into which the alternatingly adjacent fluid channels 2, 3; 12, 13; 32, 33 merge. For the sake of clarity, the fluid channels 2, 3; 12, 13; 32, 33 in simplified form compared to the arrangement in FIG. 1b. In contrast to the mixer plate 20 according to FIG. 1b, the inlet chambers 4, 14, 34 in the plane of the mixer plate 20 are funnel-shaped from the openings of the fluid channels 2, 3; 12, 13; 32, 33 formed tapering to the focusing channel 5, 15, 35. The focusing channels 5, 15, 35 themselves narrow in their width up to the junction with the common vortex chamber 16. The arrangements of fluid channels 2, 3; 12, 13; 32, 33, from inlet chambers 4, 14, 34 and focusing channels 5, 15, 35 are arranged equidistantly on the circumference of the common vortex chamber 16, which is circular in the plane shown, such that the focusing channels 5, 15, 35 open tangentially into them. An outlet channel 7 is arranged in the cover plate located above the mixing plate 20 and above the center of the common swirl chamber, the position of which is indicated here by a dashed circular line. The fluids are fed separately into the fluid channels by means of a base and distributor plate analogous to the arrangement shown in FIG. The feeds can be designed in such a way that the fluid channels 2, 12, 32 for one fluid and the fluid channels 3, 13, 33 for the other fluid are each supplied with the same fluid, so that the static micromixer can be used to mix two fluids. However, it is also conceivable to design the feeds in such a way that three or more fluids can be mixed with the micromixer. Bid here different supply options. The formation of fluid lamellae of the sequence ABACAB in the common swirl chamber 16 is explained here as an example.

FIG. 3 shows a top view of a mixer plate 20 with a swirl chamber 16, into which two focusing channels 5, 15 and two feed channels 9a, 9b open. The focusing channels 5, 15 are each in fluid communication with an inlet chamber 4, 14 into which the alternately adjacent fluid channels 2, 3; 12, 13 merge. For the sake of clarity, the fluid channels 2, 3; 12, 13 compared to the arrangement shown in Figure lb simplified. In contrast to the mixer plate 20 according to FIG. 1b, here the inlet chambers 4, 14 are funnel-shaped in the plane of the mixer plate 20 from the openings of the fluid channels 2, 3; 12, 13 designed tapering to the focusing channel 5, 15. The focusing channels 5, 15 themselves narrow in their width up to the junction in the common swirl chamber 16. The arrangements of fluid channels 2, 3; 12, 13, from inlet chambers 4, 14 focusing channels 5, 15 and feed channels 9a, 9b are arranged equidistantly on the circumference of the swirl chamber 16, which is circular in the plane shown, in such a way that the focusing channels 5, 15 and the feed channels 9a, 9b alternately tangentially in flow into this. An outlet channel 7 is arranged in the cover plate located above the mixing plate 20 and above the center of the common swirl chamber, the position of which is indicated here by a dashed circular line. The separate supply of the fluids into the fluid channels and the supply channels 9a, 9b is carried out by a base and distributor plate analogous to the arrangement shown in FIG. The feeds can be designed such that a first fluid is fed to the fluid channels 2, 12, a second fluid to the fluid channels 3, 13 and a third fluid, for example an auxiliary, to the feed channels 9a, 9b, so that the static micromixer is used to mix two Fluids with simultaneous addition one of the mixture stabilizing auxiliary can be used. In this exemplary embodiment, too, it is conceivable to design the feeds in such a way that three or more fluids can be mixed with the micromixer with the simultaneous addition of an auxiliary agent which stabilizes the mixture. A wide variety of feeding options are available here. The formation of fluid lamellae of the sequence ABACAD in the common swirl chamber 16 is explained here as an example.

FIG. 4 shows a mixer plate 20 for producing gas-liquid dispersions with four focusing channels 5, 15, 35, 45 opening into a common swirl chamber 16 in a top view. In contrast to the mixer plate 20 according to FIG. 2, two focusing channels 15, 45 for the introduction of liquids or liquid mixtures open approximately tangentially and two further focusing channels 5, 35 for the introduction of gases or gas mixtures into the swirl chamber 6 at a steeper angle. The focusing channels 5, 15, ^'35, 45 communicate respectively with an inlet chamber 4, 14, 34, 44 fluidically in which the alternating adjacent fluid channels 2, 3, 32, 33, 42, 43, 52, 53 open into compound. For the sake of clarity, the fluid channels 2, 3, 32, 33, 42, 43, 52, 53 are also shown in simplified form in this figure compared to the arrangement in FIG. 1b.

FIG. 5 shows a partial section through a static micromixer 1, which has a cylindrical swirl chamber 116 into which a plurality of focusing channels 105, 105 '- 105 "', 115, 115 '- 115"', 135, 135 - 135 "' Merging essentially tangentially in several planes For this purpose, a plurality of mixer plates 120, 121, 122 are stacked one above the other with spacer plates 125 interposed.

Different total fluid flows are fed into the swirl chamber 116 alternately via the focusing channels of one level or alternately via the focusing channels of different levels. To the training To support spiral flow patterns, the fluid flows are introduced approximately tangentially into the swirl chamber 116. The supply of the combined fluid flows from the inlet chambers into the focusing channels takes place through vertical bores through the mixer and spacer plates 120, 121, 122 and 125. The bores penetrate a defined number of mixer and spacer plates and thus provide the fluidic connection to a specific one Level from focusing channels. The discharge of the fluid flows from the swirl chamber takes place via a central outlet on the lower end face of the swirl chamber. As a result, a velocity component is superimposed on the flow along the cylinder axis and helical rather than spiral streamlines are formed.

embodiment

The static micromixer shown in FIGS. 1 a and 1 b was realized by means of micro-structured glass plates. The mixer plate 20 and the distributor plate 26 each had a thickness of 150 μm and the final base plate 22 and cover plate 21 each had a thickness of 1 mm. Bores with a diameter of 1.6 mm were selected as feeders 23, 23 ', 23 ", 24, 24', 24" in the cover plate 21, the mixer plate 20 and the distributor plate 26. The distributor plate 26 had two rows of 15 elongated holes each with a length of 0.6 mm and a width of 0.2 mm as distributor structures 27, 28. The fluid channels 2, 3 of the mixer plate 20 had a width of 60 μm with a length of 11.3 mm and a length of 7.3 mm. In the area of the mouth of the channels 2,3 in the inlet chamber 4, the webs located between the channels 2,3 had a width of 50 μm. The width of the inlet chamber 4 in the region of the mouth of the fluid channels 2, 3 was reduced from 4.3 mm to the opposite side to a width of the focusing channel of 0.5 mm. Since all structures of the mixer plate 20 have been realized as openings, the fluid channels 2, 3, the inlet chamber 4, the Focus channel 5 and the vortex chamber 6 to a depth that is equal to the thickness of the mixer plate of 150 microns. The length of the inlet valve 4, ie the distance between the confluence of the fluid channels 2, 3 and the confluence of the focusing channel 5, was only 2.5 mm in order to allow the combined fluid streams to be quickly derived and focused. The ratio of the cross-sectional area of the focusing channel to the sum of the cross-sectional areas of the fludica channels 2, 3 was thus 1 to 3.6. With a length of 2.5 mm of the focusing channel 5, a ratio of length to width of 5 to 1 was achieved. The focusing channel 5 merged longitudinally into the channel-like swirl chamber 6 with a length of 24.6 mm and a width of 2.8 mm. The opening angle of the side surfaces of the swirl chambers 6 in the transition region between the swirl chamber 6 and the focusing channel 5 was 126.7 °. The four plates shown in FIG. 1 a had an external dimension of 26 x 76 mm. The plates were structured photolithographically using photostructurable glass using a method as described in Microelectronic Engineering 30 (1996), pp. 497-504. The plates were fluidly sealed together by anodic bonding.

LIST OF REFERENCE NUMBERS

Static micromixer fluid channel for fluid a fluid channel for fluid b inlet chamber focusing channel swirl chamber outlet channel concave wall supply channel fluid channel for fluid a fluid channel for fluid b inlet chamber focusing channel swirl chamber mixer plate cover plate base plate supply for fluid a supply for fluid b discharge distributor plate distributor structure for fluid a distributor structure for fluid b fluid channel for fluid a fluid channel for fluid b inlet chamber focusing channel fluid channel for fluid c fluid channel for fluid d inlet chamber

focusing channel

Fluid channel for fluid c

Fluid channel for fluid d

focusing channel

Fluid spiral, 105 'focusing channel, 115' focusing channel

swirl chamber

mixer plate

Groove a, b connecting groove a distributor groove b distributor groove

Groove a connecting groove

Spacer plate, 135 'focusing channel

Claims

claims

1. A method for mixing at least two fluids, comprising the following steps:

Bringing together a plurality of separate fluid flows of the two fluids to form alternately adjacent fluid lamellae of the two fluids,

Removal of the combined fluid lamellae with formation of a focused total fluid flow,

Introducing the focused total fluid flow as a fluid jet into a swirl chamber, forming an inwardly flowing fluid spiral,

Deriving the mixture formed from the center of the fluid spiral.

2. The method according to claim 1, characterized in that fluid flows of the two fluids, each with a width in the range from 1 μm to 1 mm and a depth in the range from 10 μm to 10 mm, are combined to form fluid lamellae.

3. The method according to claim 1 or 2, characterized in that the combined fluid lamellae are focused such that the ratio of the cross-sectional area of the focused total fluid flow to the sum of the cross-sectional areas of the fluid lamellae to be brought together in each case perpendicular to the flow direction in the range of

1: 1.5 to 1: 500, preferably in the range from 1: 2 to 1:50.

4. The method according to any one of claims 1 to 3, characterized in that the ratio of the length of the focused total fluid flow to its width in the range from 1: 1 to 30: 1, preferably in the range from 1.5: 1 to 10: 1, lies.

5. The method according to any one of the preceding claims, characterized in that the focused total fluid flow is introduced into a swirl chamber (6) which has a substantially round or oval shape in the plane of the fluid spiral being formed.

6. The method according to any one of the preceding claims, characterized in that the focused total fluid flow is introduced at an acute angle or preferably tangentially into the swirl chamber (6).

7. The method according to any one of the preceding claims, characterized in that in the combined fluid lamellae or in the focused total fluid flow or in the swirl chamber (6) a further fluid, for example a fluid having a mixture stabilizing auxiliary, is introduced.

8. The method according to any one of the preceding claims, characterized in that the first two method steps are carried out simultaneously at least two spatially separate locations and the focused total fluid flows thus obtained are introduced into a plane of the swirl chamber in such a way that a common inward flowing fluid spiral forms, which is formed from at least two individual fluid spirals lying one inside the other.

9. The method according to any one of claims 1 to 7, characterized in that the first two process steps are carried out simultaneously at least two spatially separate locations and the focused total fluid flows thus obtained are fed to the swirl chamber in different planes in such a way that superimposed on each other form fluid spirals flowing inside.

10. The method according to any one of claims 8 or 9, characterized in that the same and / or different fluids are used in the two process steps carried out two or more times.

11. The method according to any one of claims 8 to 10, characterized in that the same and / or different total fluid flows are introduced at different angles into the swirl chamber (6, 16) in the two process steps carried out two or more times.

12. Static micromixer (1) for mixing at least two fluids with

a multiplicity of alternately adjacent fluid channels (2, 3, 12, 13, 32, 33, 42, 43, 52, 53) for the separate supply of the fluids as fluid lamellae,

at least one inlet chamber (4, 34, 44) into which the fluid channels (2,

3, 12, 13, 32, 33, 42, 43, 52, 53) open, and

a focusing channel (5, 15, 35, 45, 105, 105 ', 115, 115') fluidly connected to the inlet chamber (4, 34, 44) for removing the fluid lamellae combined in the inlet chamber (4, 14, 34, 44) to form a focused total fluid flow,

marked by

a vortex chamber (6, 16, 116) into which the focusing channel (5, 15, 35, 45, 105, 105 ', 115, 115') opens in such a way that the focused total fluid flow enters as a fluid jet, forming an inward flowing fluid spiral (100), and

at least one outlet channel (7) fluidly connected to the swirl chamber (6, 16, 116) for discharging the mixture formed.

13. Micromixer according to claim 12, characterized in that the adjacent fluid channels (2, 3, 12, 13, 32, 33, 42, 43, 52, 53) have a width in the range from 1 μm to 1 mm and a depth in the range have from 10 μm to 10 mm.

14. Static micromixer according to claim 12 or 13, characterized in that the inlet chamber (4, 14, 34, 44) has a concave wall (8) opposite the fluid channels, into which the focusing channel (5, 15, 35, 45, 105, 105 ', 115, 115') opens in the middle.

15. Micromixer according to claim 12 or 13, characterized in that the inlet chamber (4, 14, 34, 44) has a constant cross section in the flow direction.

16. Micromixer according to one of claims 12 to 15, characterized in that the focusing channel (5, 15, 35, 45, 105, 105 ', 115, 115 ') has a constant or tapering cross-section in the direction of flow.

17. Static micromixer according to one of claims 12 to 16, characterized in that the ratio of the cross-sectional area of the focusing channel (5, 15, 35, 45, 105, 105 ', 115, 115') at least in the region of the confluence with the vortex chamber ( 6, 16, 116) to the sum of the cross-sectional areas of the fluid channels (2, 3, 12, 13, 32, 33, 42, 43, 52, 53) opening into the inlet chamber (4, 14, 34, 44) each perpendicular to the Channel axis is in the range from 1: 1.5 to 1: 500, preferably in the range from 1: 2 to 1:50.

18. Static micromixer according to one of claims 12 to 17, characterized in that the ratio of the length of the focusing channel (5, 15, 35, 45, 105, 105 ', 115, 115') to its width at least in the region of the confluence the width of the vortex chamber (6, 16, 116) is in the range from 1: 1 to 30: 1, preferably in the range from 1.5: 1 to 10: 1.

19. Static micromixer according to one of claims 12 to 18, characterized in that the swirl chamber (6, 16, 116) in a plane in which the focusing channel (5, 15, 35, 45, 105, 105 ', 115, 115 '), has a substantially round or oval cross-section.

20. Static micromixer according to one of claims 12 to 19, characterized in that the swirl chamber (6, 16, 116) has a substantially cylindrical shape.

21. Micromixer according to claim 20, characterized in that the pressure gauge of the swirl chamber (6, 16, 116) is 2 mm to 20 cm, preferably 5 mm to 10 cm.

22. Static micromixer according to one of claims 12 to 21, characterized in that below and / or above a central region of the swirl chamber (6, 16, 116) one or more outlet channels (7) open out.

23. Static micromixer according to one of claims 12 to 22, characterized in that the fluid channels (2, 3, 12, 13, 32, 33, 42, 43, 52, 53), the inlet chamber (4, 14, 34, 44 ), the focusing channel (5, 15, 35, 45, 105, 105 ', 115, 115') and the swirl chamber (6, 16, 116) are arranged in one plane and have the same depth.

24. Static micromixer according to one of claims 12 to 23, characterized in that in the inlet chamber (4, 14, 34, 44), the focusing channel (5, 15, 35, 45, 105, 105 ', 115, 115') or the swirl chamber (6, 16, 116) opens into one or more supply channels (9a, 9b) for supplying a further fluid, for example a fluid having an auxiliary substance stabilizing the mixture.

25. Static micromixer according to one of claims 12 to 24, characterized in that the focusing channel (5, 15, 35, 45, 105, 105 ', 115, 115') at an acute angle or preferably tangentially into the swirl chamber (6, 16, 116) is arranged at the mouth.

26. Static micromixer according to one of claims 12 to 25, characterized in that the plurality of adjacent fluid channels (2, 3, 12, 13, 32, 33, 42, 43, 52, 53), the inlet chamber (4, 14, 34, 44) into which the fluid channels (2, 3, 12, 13, 32, 33 , 42, 43, 52, 53), and the focusing channel (5, 15, 35, 45, 105, 105 ', 115, 115'), which is in fluid communication with the inlet chamber (4, 14, 34, 44), respectively are present two or more times and the two or more focusing channels (5, 15, 35, 45, 105, 105 ', 115, 115') open in one plane into which a common swirl chamber (6, 16, 116) opens.

27. Static micromixer according to claims 12 to 26, characterized in that the plurality of adjacent fluid channels (2, 3, 12, 13, 32, 33, 42, 43, 52, 53), the inlet chamber (4, 14, 34, 44) into which the fluid channels (2, 3, 12, 13, 32, 33, 42, 43, 52, 53) open, and the focusing channel (4, 14, 34, 44) which is in fluid communication with the inlet chamber (4, 14, 34, 44) 5, 15, 35, 45, 105, 105 ', 115, 115') are each present two or more times and the two or more focusing channels (5, 15, 35, 45, 105, 105 ', 115, 115') open into several levels into a common vortex chamber (6, 16, 116).

28. Static micromixer according to claim 26 or 28, characterized in that the two or more focusing channels (5, 15, 35, 45, 105, 105 ', 115, 115') at different angles in the swirl chamber (6, 16, 116) flow into.

29. Static micromixer according to one of claims 12 to 28, characterized in that the fluid guide structures, such as the fluid channels (2, 3, 12, 13, 32, 33, 42, 43, 52, 53), the inlet chambers (4, 14 , 34, 44), the focusing channels (5, 15, 35, 45, 105, 105 ', 115, 115'), feeders (23, 23 ', 23 ", 23'", 24, 24 ', 24 ", 24 '") and the swirl chambers (6, 16, 116), as recesses and / or Breakthroughs in plates made of a material that is sufficiently inert for the fluids to be mixed are introduced and these open structures are completed by the stacking of the plates and by at least one cover and / or bottom plate (21, 22) that is fluidly tightly connected to the plate stack, the Cover and / or base plate (21, 22) have at least one feed (23, 23 '", 24, 24'") for the two fluids and / or at least one drain (25) for the mixture formed.

30. Static micromixer according to claim 29, characterized by an between a mixer plate (20) with fluid channels (2, 3, 12, 13, 32, 33, 42, 43, 52, 53), inlet chamber (4, 14, 34, 44 ), Focusing channels (5, 15, 35, 45, 105, 105 ', 115, 115') and vortex chamber (6, 16, 116) and the base plate (22) arranged and fluidly connected to this with the distributor plate (26) Feeders (23 ", 24") for separately feeding the fluids from the feeders (23 '", 24'") in the base plate (22) into the fluid channels (2, 3, 12, 13, 32, 33, 42, 43 , 52, 53) in the mixer plate (20).

31. Use of the method and / or the static micromixer according to one or more of the preceding claims for reacting at least two substances, both substances being contained in an introduced fluid or a first substance in a first fluid and a second substance in a further introduced fluid.

32. Use of the method and / or the static micromixer according to one or more of the preceding claims for producing a gas-liquid dispersion, at least one introduced fluid being a gas or a gas mixture and at least one further introduced fluid being a liquid, a liquid mixture, a solution, a dispersion or an emulsion.