DE102005003965A1 - Micro-mixer for precipitation and/or crystallization reactions comprises reverse flow prevention unit placed between mixing and reaction zone and at least one channel for introducing partial stream - Google Patents

Abstract

A micro-mixer comprises a first channel for introducing a first partial stream (6), a second channel for introducing a second partial stream (7), and a reverse flow prevention unit placed between the mixing and reaction zone (10) and at least one of the channels.

Description

The The invention relates to a micromixer for mixing at least two to form precipitates or suspensions reacting fluids.

By the use of microstructured components in apparatus for mixing Fluids have advantages in product quality as well as mixing times and size of required Apparatuses compared to conventional ones Structures reduced. An essential feature of microstructured components are the small dimensions of the fluid channels, which are typically in the range between 10 and 5,000 μm are settled. For this reason, for example, with multilamination mixers fine fluid fins are generated, between which, due to their small thickness a rapid mass transfer by diffusion take place can. The small dimensions of the flow-through cross sections require but also special measures, to protect them against deposits and blockages during operation. So For example, in the feed of such components particulate filter used, with the selection of the separation limit on the dimensions oriented to the microstructure.

Apart from particles that can get into a micromixer via the inlet channels for the inflowing media, there is also the risk of deposits and blockages due to chemical-physical processes that take place in the components, for example after mixing. For example, solid products can be formed by precipitation as a result of a neutralization reaction, by exceeding the solubility product, or by crystallization of the reaction product upon reaction of organic or inorganic compounds. From the DE 101 48 615 A1 For example, a method for carrying out chemical processes is known in which at least two fluids reacting to form precipitates or suspensions are combined in a micromixer having fluid channels. In order to prevent clogging of the micromixer, the at least two fluids are introduced separated by a further separating fluid into a mixing chamber or a reaction zone. A premature reaction of the fluids is thereby avoided and shifted to a non-critical region of a mixer device. Another way to prevent the deposits and blockages in the microstructures, is in the DE 202 18 972 U1 described. There, the components of a static lamination micromixer are designed to be easily accessible and easy to clean. In a very simple manner, suspensions in microstructured components can then still be handled to the exclusion of blockages, if the dimensions of the microstructures are significantly larger than the occurring maximum particle dimensions. In the DE 100 31 558 A1 Therefore, in the context of conditioning processes, organic pigments are recommended to be sized within a reactor such that the smallest clear width of the microstructures is advantageously about ten times greater than the diameter of the largest particles. However, this also increases the characteristic dimensions of the components, and one speaks often no longer of micro, but of mini reactors. Even if these measures provide a remedy with regard to the risk of clogging, this often also reduces the usefulness of the microstructures for process control and product quality. In any case, to avoid deposits in the outlet zone of a mixer or reactor dead volumes and sharp deflections in the wall should be avoided. If there are still blockages, then active cleaning measures can help. In the DE 101 43 189 A1 describe a method and a device for process-accompanying cleaning of micro and mini reactors. The micro- or mini-reactor is cleaned by a controlled pressure increase with subsequent sudden relaxation or by a gas pressure surge cyclically or by means of a scheme. For example, wall covering, which has formed, for example, from solids participating in the chemical synthesis or the physical process, is almost completely removed. In addition or as an alternative to such cleaning methods, special design measures and special types of process control are known which prevent the formation of wall coverings and the clogging of the microstructured components. As mentioned above, is from the DE 101 48 615 A1 the use of a separating fluid known. However, the separation fluid may adversely affect the reaction by causing dilution of a single-phase mixture and reducing the supersaturation for the precipitation reaction and hence the yield of the reaction. In addition, such a separation fluid must then be separated from the product stream. In the DE 101 19 718 A1 describes a construction for the preparation of inhalable drugs, which consists of a micromixer, a Segmenter and a subsequent dwell. In the micromixer, for example, two liquid components are mixed, which are divided into individual units in the segmenter, wherein the individual units are separated by a different phase. This biphasic system is then heated in a residence zone to initiate the reaction leading to the formation of solids. The segmentation of the reacting phase prevents the formation of larger agglomerates. Furthermore it is Known to take advantage of flow effects to produce small solid units. So will in the EP 1 165 224 B1 described how at least two liquid media from micro-nozzles are shot at each other in a thin jet under high pressure. In the collision point, fine droplets are generated in which then physical-chemical transformations take place and their size also determines the size of the solid reaction products. These are removed by an auxiliary flow, which can be a gas or a liquid, which must then be separated. In the DE 198 51 253 A1 describes the preparation of bisphenol A using controlled turbulence. The turbulence is generated by a suitable flow guidance, and with it the shape and size of the particles can be adjusted. The EP 0 913 187 B1 describes a process for continuous polymerization with a micromixer for reaction liquids. To produce polymers, two or more monomers are ejected from nozzles and combined in one or more steps. The mixtures are then passed by pressure from the mixing chamber. The point of collision between two jets of fluids is some distance from the nozzles, which are used to angle the fluids to each other, so that blockage of the jets can be precluded. WO 01/62374 A2 describes a process for the preparation of nanosuspensions. The fluids enter after mixing in a mixing chamber in a nozzle, which they leave via an outlet channel. The mixing is achieved by turbulence, so that deposits and blockages of the microstructures is prevented in this way.

In summary It should be noted that the previously used solutions against deposits and Blockages of the microstructures in the following measures consist: the components of the microstructures are constructed that they are easily accessible and are easy to clean, they are also significantly larger than the particles are built over it can out Dives and additional Channels for auxiliary currents provided be. The procedures for avoiding deposits and blockages Microreactors provide a process-accompanying cleaning, suitable Flow guides, Mixing away from the supply ducts or generating turbulence. All measures is common that they affect the efficiency of microreactors or big ones additional Mean effort.

task The object of the present invention is to provide a micromixer for mixing of at least two fluids to provide a fast and efficient mixing of fluids and simultaneously good resistance across from undesirable Has deposits and blockages in the microstructures.

The Task is surprisingly by the micromixer according to the invention solved.

The invention therefore provides micromixers for mixing at least two fluids reacting to form precipitates or suspensions with a first channel for the supply of a first partial flow (US Pat. 6 ) and with a second channel for the supply of a second partial flow ( 7 ), which in flat, preferably narrow entrance slits ( 19 . 20 ) into a mixing and reaction zone ( 10 ) and the mixing and reaction zone ( 10 ) via an outlet channel ( 11 ), characterized in that between the mixing and reaction zone ( 10 ) and at least one channel for the supply of a partial flow ( 6 . 7 . 37 ) a backflow barrier ( 9 . 17 ) is arranged. Preferably, one of the inlet gaps in the region of its confluence with the reaction zone has formed a backflow barrier.

Of the micromixer according to the invention for mixing at least two to form precipitates or suspensions reacting fluids has a first channel for the Supply of a first partial flow and a second channel for the supply of a second partial flow on. Both channels preferably open in narrow Entrance columns in a mixing and reaction zone and leave these over one Outlet channel. Between the mixing and reaction zone and at least a channel for the supply of a partial flow is arranged a backflow preventer. As an advantage of the micromixer according to the invention it turns out that no backflows occur in the mixing and reaction zone. As a result, the associated precipitation reactions in the inlet areas avoided the mixing and reaction zone. In the mixing and reaction zone is the primary one Germination for The later resulting precipitations and crystallization processes. For producing finely dispersed solids, as they are in precipitation or suspensions must occur high nucleation rates can be achieved. In large-scale processes will be Therefore, in corresponding mixing and reaction zones high shear rates through fast currents or intensive stirring realized. High nucleation rates with the help of microstructured Components can be achieved when fine fluid jets in a flowing fluid be injected. The supplied Fluids can already be particle-containing.

advantageous embodiments the micromixer are the subject of the dependent claims.

A steady growth of educated kei To uniform particle size requires that the mixing and reaction zone follow a uniform flow field at low speeds. This is realized with advantage by an outlet channel with a smooth and widening geometry.

The backflow of the micromixer is preferably as a check valve or as a membrane assembly educated. The bias of the spring of the check valve can help with be adjusted by mechanical means. In a particularly advantageous execution can the spring preload and / or the spring constant and thus the set pressure or the opening behavior the check valve while be adjusted from the outside of the operation of the mixer. Especially in an integration of the check valve in an external control loop, the use of an electrical, pneumatic, hydraulic or electromagnetic drive for the check valve as advantageous.

In a further advantageous embodiment of the mixer can the width of at least one of the entrance slits and / or the characteristic Dimension of the mixing and reaction zone during operation of the mixer be set continuously or stepwise. The attitude of these sizes can mechanical, pneumatic, hydraulic, piezoelectric, electrostatic or electromagnetic drive. In a particularly advantageous embodiment of the mixer, this can Sizes beyond that as manipulated variables in one Be integrated loop.

When Controlled variables for the adjustment the response pressure or opening behavior the check valve, the width of at least one of the entrance slits and / or the characteristic one Dimension of the mixing and reaction zone are preferably chemical or physical properties of the mixed or reaction product, especially those that are characterized by a fast online measurement determine, e.g. Temperature, color, light scattering or absorption behavior, pH or electrical conductivity, used.

The inlet gaps for the various partial flows can be linear - then preferably parallel - or radial, or curved - then preferably annular concentric or axially in sequence - be arranged. Linearly arranged entrance gaps are particularly advantageously suitable for realizing micromixers according to the invention for high volume flows, eg above a few 100 L / h. In the case of a likewise advantageous annular concentric arrangement, the non-return valve can be both part of the inner and / or the outer channel. In the event that the check valve is part of the inner channel, the operation of the mixer is in the 1 to 5 described. In the case of a further advantageous embodiment with two annular, provided with diaphragm valves as Rückströmsperren entry columns in an axial arrangement, the operation of the mixer in 6 described. The likewise advantageous case of a check valve formed in the outer entrance slit is in 8th shown.

In a further preferred embodiment of the invention, the micromixer consists of at least one internal and one external non-return valve, see 9 , In the 10 illustrated embodiment of the invention additionally allows the mixing of more than two components.

The inflowing into the mixing and reaction zone streams can be fanned in many ways by an appropriate design of the flow, whereby the mixing speed and thus the nucleation rate is increased. In a preferred embodiment of the invention, as described in the 1d . 2 B . 3a and 3b are slotted plates, eg radial slotted plates ( 16 ), which split the sub-stream or sub-streams into a plurality of sub-beams. In a further embodiment of the invention, certain structures, such as a corrugation on the channel walls or, as in 4 shown, applied directly in the inflow region of the respective partial flow on the edge of the check valve.

In a further advantageous embodiment of the micromixer according to the invention is the backflow stop electrically, pneumatically, hydraulically or electromagnetically controllable. Particularly advantageous is an embodiment in which the backflow lock through an external pathogen can be moved periodically with high frequency. Especially preferred is here execution as a check valve with a slight valve disc and periodic excitement through a piezoelectric vibrator or electromagnet. As exciter frequencies In this case, frequencies in the megahertz range are particularly preferred.

For use of the mixer according to the invention at high volumetric throughputs of the incoming substreams, it is preferable to use a mixer unit consisting of several identical arrangements of entry slits operated in parallel, each with separate backflow locks and mixing zones in a common housing and with common fluid supply, the fluid supply to the individual arrangements preferably being such designed and the opening pressures of each Return flow locks are matched to one another such that prevail in all mixing zones of the mixer unit in operation the same mixing and flow conditions.

The micromixer according to the invention are preferred by precision engineering and microfabrication techniques produced. This includes all common ones Methods, such as the machining, spark erosion or material processing with laser radiation. Will be a check valve as Rückströmsperre used, so its sealing effect in an advantageous manner Equipped with an elastomer seal. In another advantageous embodiment becomes the sealing effect of the check valve achieved by grinding the valve cone into its seat. These Shape of the seal is particularly advantageous, when the mixer is to be used at high temperatures.

The Micromixers can while advantageous from the commonly used in process engineering materials like stainless steels, Nickel-based alloys, titanium. or tantalum are made. Especially when using the micromixer under high temperatures or with corrosive However, media are also preferred ceramic materials such as e.g. Alumina, zirconia, silicon nitride, aluminum nitride or Use silicon carbide.

The microreactors according to the invention are preferred for Crystallization and precipitation reactions used.

If into the micromixer substances that spontaneously crystallize, it makes sense to use the backflow valves provided with cleaning pins, preferably a needle-shaped tip exhibit. The cleaning pens free the microstructures every opening and closing process from any deposits. The cleaning pens can either against the flow direction in a respective outlet opening introduced or in the flow direction. Be any deposits pushed out by the cleaning pins in the flow direction, so this proves to be particularly beneficial. The microstructures can also by short-term pressing the backflow stops during operation with the help of cleaning pins of deposits be freed. The operation does not have to be interrupted for this. The short-term closing For cleaning purposes can be manually, via specifically applied pressure fluctuations or over triggered an external control loop become.

The feed the partial flows in a circular or ring-shaped Cross-section can be done under high pressure and from fine nozzles. Since crystallization processes take place in different phases, the influenced by the shear gradients, is the clash the partial flows at different angles advantageous to different velocity gradients between the substreams too realize. The partial flows Preferably meet at an angle between 5 and 175 ° to each other. Meet the partial flows at acute angles to each other, so has a major component their Movement in the outflow direction, so that the relative velocities of the individual streams are slow assimilate. That way you can At the injection point high shear gradients are realized to the To favor nucleation. The subsequent decrease in relative velocities has an effect Cheap on the crystal growth. At an injection of a partial flow at right angles higher Velocity gradients realized near the dosing which results in a high nucleation rate. Then you can a first partial flow moves through a second partial flow in the outflow direction be, with the relative velocity between the partial streams is reduced. The nucleation rate is Continue to increase if the injection under a dull Angle takes place, for example, 175 °. In this case, the highest velocity gradient at the injection point.

crystallization and precipitation products need in many cases a further treatment, for example, the pH in the product stream by addition of an acid or a lye or with the help of inhibitors or stabilizers To control crystal size. Often they are for it additional dosing required. These can be in one or more be implemented in series devices. In this It may also be necessary to identify the inflowing media, an entire component, the mixing and reaction zone or more subsequent Tempered components targeted.

A Influencing the particle size of the formed Crystallization or precipitation products can be done by the cross section of the outlet channel regularly or irregularly designed becomes. Because of their opposite The medium of different density, the precipitation products usually move at a slower rate than the flowing liquid. At a bottleneck there is an acceleration of the flow, on an extension to calm the flow. That way you can targeted velocity gradients are imprinted, which is a smashing large aggregates or cause their enlargement.

Precipitation and crystallization products tend to deposit on the walls of the micromixer depending on their properties, wall roughness and flow conditions. It therefore proves to be beneficial to include the effluent products in the outlet channel in a jacketed jet which is fed between the wall of the outlet channel and the effluent product as a closed film.

In another advantageous embodiment of the micromixer this is in the region of the outlet channel of a anti-adherence material, e.g. PTFE, manufactured, the wall of the outlet channel is made with such a material coated and / or the surface this wall is, e.g. by using a polish or electropolishing process, very smooth.

at the generation of particles or nanoparticles is preferred at least one of the part streams supplied to the mixer Liquid, gas, a condensed gas, a supercritical Solvent, a mist, a gas with solid, optionally catalytically active Ingredients or an emulsion. or as a result of in the Mixing zone occurring processes in the mixer forming medium.

at the precipitation reactions For example, the reaction may be by the supply of another stream be interrupted or it can other layers of other solids are produced by precipitation Particles are applied. In this way, the mixer is suitable et al advantageous for the production of particles or nanoparticles having a plurality of layers arranged in a concentric sequence different substances. For influencing the particle size as well for the purpose of transferring the particles produced in another fluid phase can also be surface-active Substances are supplied to the product stream.

Of the inventive mixer also allows the production of nanoparticles in the gas phase, wherein at least one of the supplied substreams already finely divided particles such as e.g. Nanoparticles with catalytic May contain effects. In this way, the mixer may e.g. advantageous for mixing with catalytically active nanoparticles offset gaseous Hydrocarbons and ammonia gas are used by chemical Implementation of the mixture thus produced carbon nanotubes too produce.

Further is advantageous with the mixer, the in-situ production of emulsions possible, which therefore also for the implementation of precipitation and Crystallization reactions and for the production of nanoparticles can be used if they are very unstable.

A Another advantageous use of the mixer consists in the precipitation or Crystallization of particles using supercritical solvents as well as highly compressed or condensed gases, since the micromixer in a particularly advantageous manner allows working at high pressures. In case of such use, the mixture product may be downstream downstream the mixer in an advantageous manner by adiabatic relaxation of the carrier medium chilled become. Such a cooling can be done very quickly and thus advantageously one initiate rapid nucleation or very soon after insertion Particle growth, the chemical reaction or further particle growth to stop.

These Uses are also the subject of the invention.

For more complex, eg multi-stage reactions of the mixer according to the invention can also be combined with other components that are necessary for the construction of a microreaction system, such as heat exchangers, electrical heating modules ( 27 ), thermal isolators ( 25 ), further through-flow metering points ( 26 ) or mixers, such as, for example, lateral flow mixers, control units, etc., as well as measuring devices, for example for determining temperatures, pressure, pH, electrical or optical properties of the substances flowing through. In particular downstream of the micromixer are preferably to use those components that are not clogged by the particles generated in the mixer or otherwise impaired in their function and / or can be disassembled and cleaned with little effort.

Downstream behind The mixer arranged metering can also be used to control the temperature Product stream are used by this a suitably tempered Supply fluid.

Of the micromixer according to the invention will be explained by way of example with reference to the following figures.

It demonstrate:

1a a micromixer according to the invention, in particular a valve mixer, with a check valve in longitudinal section,

1b an enlarged view of the micromixer of 1a to the environment of the mixing and reaction zone,

1c the flow patterns in the micromixer 1a .

1d the flow patterns in the magnö view of the 1b .

2a a spacer plate for adjusting the height of the entrance gap for the first partial flow,

2 B a spacer disk with a microstructured design,

3a a perspective view of the mixing and reaction zone of the micromixer with check valve,

3b a cross section through the mixing and reaction zone of 3a .

4 a longitudinal section through a valve stem with microstructured design of the surface with an enlarged view near the wall,

5a a longitudinal section through a valve mixer with narrow first entrance gap and closed check valve,

5b a longitudinal section through the valve mixer 5a with open check valve,

5e a longitudinal section through a valve mixer with a wide first entrance gap and closed check valve,

5d a longitudinal section through the valve mixer 5c with open check valve,

6a a micromixer according to the invention with membrane arrangement in longitudinal section,

6b an enlarged view of the micromixer of 6a in the surrounding area of the mixing and reaction zone,

6c the flow patterns in the micromixer the 6b .

6d the flow patterns in the enlarged view of 6b .

7 a valve mixer according to the invention in combination with a further metering point and a heated outlet channel.

8th a valve mixer with an external check valve

9 a valve mixer with an external and an internal check valve

10 a valve mixer having an inner and an outer non-return valve, which has formed an additional flow channel and entrance slit for supplying a further partial flow.

11 a large volume flow valve mixer, which is designed as a parallel arrangement of a plurality of identical valve mixing units in a common housing with the common supply of the partial streams and common discharge of the mixture product.

In the 1a an inventive valve mixer is shown in longitudinal section. The valve mixer consists of a base body 1 , from a middle part 2 and from a lid 3 , These three components are outward through two O-rings 4 . 5 sealed. Here is the first O-ring 4 between the main body 1 and the middle part 2 arranged, and the second O-ring 5 is located between the middle part 2 and the lid 3 , The two partial streams 6 . 7 come from the left and from the right into the main body 1 one. They are each indicated by horizontally extending black arrows. The first partial flow 6 becomes in the left area of the main body 1 passed through a hole leading up into an annular channel 8th for the first partial flow 6 empties. From the ring channel 8th occurs the first partial flow 6 just above a valve tappet 9 in a mixing and reaction zone 10 , The second partial flow 7 is guided centrally through the micromixer. He flows around the valve lifter 9 and will have several holes 12 the bottom of the head of the valve lifter 9 fed from there into the mixing and reaction zone 10 , The reaction mixture, consisting of the first part stream 6 and the second partial flow 7 , is via an outlet channel 11 derived. The valve lifter 9 , the mixing and reaction zone 10 and the outlet channel 11 are designed rotationally symmetrical. By adjusting a spiral spring 13 , a mother 14 and a locknut 15 It determines the force required to move the valve lifter 9 move upwards. This force must be applied by the pressure difference between the pressure in the holes 12 for the second partial flow 7 and the mixing and reaction zone 10 consists. Due to this pressure difference, the valve tappet 9 moved up and gives the way for the second partial flow 7 into the mixing and reaction zone 10 free. If there is a pressure drop in the holes 12 or rises due to deposits and blockages in the mixing and reaction zone 10 or in the outlet channel 11 the pressure is strong, so the valve tappet 9 down against the valve body 17 pressed, and a return flow from the mixing and reaction zone 10 in the inlet area for the second partial flow 7 prevented. The micromixer is thus with a backflow barrier for the second partial flow 7 in the form of a setback equipped. The sealing effect can be further improved by the fact that between the valve stem 9 and the valve body 17 an elastomeric seal is used, which is not shown here. The valve body 17 is through a third O-ring 18 against the main body 1 sealed, allowing a mixture of the two partial flows 6 . 7 outside the mixing and reaction zone 10 is excluded. Between the valve body 17 and the middle part 2 of the micromixer is a flat shim 16 , which is in various strengths, preferably in a thickness between 20 and 5000 microns, executed. By a variation of the disc thickness of the spacer 16 the width of the gap between the valve body changes 17 and the middle part 2 from which the first partial flow 6 into the mixing and reaction zone 10 flows.

The 1b provides an enlarged view of the environment of the mixing and reaction zone 10 the micromixer of the 1a dar. The leadership of the two streams 6 . 7 is particularly clear here. The first partial flow 6 gets out of the ring channel 8th over a first entrance slit 19 whose width through the spacer disc 16 is determined in the mixing and reaction zone 10 , Due to the uniform thickness of the first entrance gap 19 the first partial flow flows 6 as a closed film from the valve body 17 out. Behind it, the first partial stream meets 6 on the likewise emerging as a closed and uniform film second partial flow 7 , The second partial flow 7 emerges from a second entrance slit 20 between the valve lifter 9 and the valve body 17 out. As a result, the two streams formed as films flow 6 . 7 parallel to each other through the mixing and reaction zone 10 to the outlet channel 11 , An improvement in the quality of mixing is achieved when the shim 16 is microstructured.

The 1c and 1d each give the flow of the 1a and 1b again. Reference signs have been omitted. The flow curves are each represented by the black arrows.

In the 2a and 2 B are each shims 16 shown how to adjust the height of the first entrance nip 19 between the valve body 17 and the middle part 2 for the first partial flow 6 be used. The spacer 16 of the 2 B is different from the one in the 2a in that it additionally has a microstructured configuration in the region of the first entrance gap 19 for the first partial flow 6 having. Through the spacer 16 in the 2 B can improve the mixing of the two partial streams 6 . 7 be achieved, since the closed film of the first partial flow 6 is decomposed into several individual beams and the speed of these individual beams at the first entrance slit 19 is significantly increased, so that the rays in the second partial stream 7 penetrate and be enclosed by this. In this way, the advantages of microtechnology for the production of small fluid fins are exploited without causing deposits and blockages of the microstructures.

The 3a and 3b provide flow patterns in the mixing and reaction zone 10 dar. Here is the 3a a perspective view of the mixing and reaction zone 10 where a shim 16 according to the 2 B has been used. The first partial flow 6 is through the black arrows 6 indicated, and the second partial flow 7 is represented by white arrows. It can be seen that the first partial flow 6 has been decomposed into several individual beams, the second partial stream 7 each enclosed. In the 3b is a cross section through the mixing and reaction zone 10 of the 3a with the corresponding flow path of the first partial flow 6 and the second partial flow 7 played.

The 4 puts a valve lifter 9 with a structured micro surface 21 The structured micro surface 21 is circled and enlarged on the right in a circle. Through the structured micro surface 21 otherwise becomes a closed fluid film between the valve lifter 9 and the valve body 17 from the second entrance slit 20 exiting second partial flow 7 divided into several individual beams. The structures of the structured micro-surface 21 are preferably between 50 and 3000 microns high, and thus become in the mixing and reaction zone 10 arranged that the webs with the valve stem closed 9 connect to the wall so that the second partial flow 7 is actually divided into separate individual beams. In this way, via the flow cross-section of the second partial flow 7 measured a field with very high velocity gradients. This favors the mixing of the first partial flow 6 with the second partial flow 7 ,

The 5a to 5d each represent a longitudinal section through a micromixer with a check valve as Rückströmsperre. Die 5a and 5b show a micromixer with a narrow first entrance slit 19 , In the 5a the check valve is closed, and in the 5b the check valve is open and gives a second entrance slit 20 for the second partial flow 7 free. The 5c and 5d make a micromixer with a wide first entrance slit 19 in the 5c the check valve is closed, and in the 5d the check valve is open and gives a second entrance slit 20 for the second partial flow 7 free. Through the narrow first entrance slit 19 in the 5b learns the first partial flow 6 a much higher speed than in the case of 5d with wide first entrance slit 19 , Via a thread or a comparable external device can be the width of the first entrance gap 19 and thus the width of the gap 30 in which the two sub-streams 6 . 7 converge, and which corresponds in its extension downstream of the mixing and reaction zone, vary.

In the 6a is a micromixer with a membrane body according to the invention 34 to be seen as a non-return valve in longitudinal section. In this micromixer are three partial streams 6 . 7 . 37 mixed together. This micromixer also comprises a basic body 1 , a middle section 2 and a lid 3 , The lid 3 consists of an upper and a lower half, and the middle part 2 It also consists of an upper and a lower part. The second and the third partial flow 7 . 37 are each via a backflow in the manner of a membrane body 34 to the mixing and reaction zone 10 directed. For the membrane body 34 Different materials come into question. It can be about different wall thicknesses of the membrane body 34 and different elasticity of the material to be applied by the differential pressure required opening force. This is similar to the setting in the micromixer 1a with non-return valve, via the coil spring 13 , the mother 14 and the locknut 15 he follows. In this embodiment of the membrane-type micromixer 34 can the first partial flow 6 either just another substream, or two more substreams 7 . 37 be mixed. It is also conceivable that the first partial flow 6 Carries particles with it. The particles can penetrate the microstructure unhindered since the micromixer has minimum dimensions in the range between 500 and 3000 μm.

In the 6b is an enlarged view of the 6a in the surrounding area of the mixing and reaction zone 10 shown.

The 6c and 6d give the flow of the 6a and 6b again. Reference signs have been omitted.

In the 7 is designed as a valve mixer module 24 shown, which together with another metering point 26 and an electric heating module 27 is combined into an integrated component. Between the designed as a valve mixer module 24 and the further metering point 26 is an isolation module 25 provided for the thermal decoupling of these adjacent components.

8th represents an advantageous embodiment of the valve mixer with annular coaxial arrangement of the entrance column 19 . 20 in which the non-return valve is formed in the region of the outer of the two inlet gaps. The return flow lock is in this case by an axially movable valve ring 41 realized by a piston seal 42 opposite the housing 43 is sealed and by a closing force effect 45 against the opposite edge of the entrance slit 19 is pressed. If the force exerted on the valve ring by the pressure of the first partial flow exceeds the closing force effect 45 , so opens the entrance slit 20 and the first partial flow enters the mixing and reaction zone 10 one.

In 9 is a further advantageous embodiment of the valve mixer with annular coaxial arrangement of the entrance column 19 . 20 shown, in which both in the region of the first and the second entrance gap, a return flow lock is formed. Here are the functional principles of the in the 5 and 8th illustrated embodiments of the valve mixer combined in an advantageous manner.

10 shows a likewise advantageous embodiment of the valve mixer, which consists of the in 9 illustrated embodiment shows that the mixing and reaction zone 10 a third partial flow 37 through a further annular entrance slit 38 that is between the entrance slit for the first 19 and the entrance slit 20 is arranged for the second partial flow, is supplied.

In 11 is a parallel arrangement of several inventive valve mixer units in a common housing ( 51 - 53 ) with common supply of the partial flows, which can be used advantageously for the mixing of larger volume flows. The two supply channels for the first ( 56 ) or second partial flow ( 57 ) are arranged in this embodiment in two superimposed planes. In each of the parallel-operated valve mixing units, the opening pressure of the check valve is individually variable in order to set a uniform volume flow ratio of the partial flows on all mixer units can. The mixture product leaves the individual mixing units in a common outlet channel, which in direct connection above in the 11 shown assembly is arranged.

1

body

2

midsection

3

cover

4

first O-ring

5

second O-ring

6

first partial flow

7

second partial flow

8th

annular channel for the first partial flow

9

tappet

10

mixing and reaction zone

11

exhaust port

12

drilling in the valve body for the second partial flow

13

spiral spring

14

mother

15

locknut

16

spacer

17

valve body

18

third O-ring

19

entrance slit for the first partial flow

20

entrance slit for the second partial flow

21

microstructured surface of the valve lifter

24

when Valve mixer trained module

25

isolation module for thermal decoupling of adjacent components

26

Further metering

27

electrical heating module

30

distance

34

membrane body

37

third partial flow

38

entrance slit for third partial flow

40

central cone

41

valve ring

42

piston seal

43

casing

45

closing force effect on valve ring

46

closing force effect on valve lifter

51

common body

52

common midsection

53

common outlet plate

56

common Supply channel for first partial flow

57

common Supply channel for second partial flow

Claims (13)

Micromixer for mixing at least two fluids reacting to form precipitates or suspensions with a first channel for the supply of a first partial flow ( 6 ) and with a second channel for the supply of a second partial flow ( 7 ), which are located in flat entrance slits ( 19 . 20 ) into a mixing and reaction zone ( 10 ) and the mixing and reaction zone ( 10 ) via an outlet channel ( 11 ), characterized in that between the mixing and reaction zone ( 10 ) and at least one channel for the supply of a partial flow ( 6 . 7 . 37 ) A backflow stop is arranged. Micromixer according to claim 1, characterized that the backflow barrier as a check valve is trained. Micromixer according to claim 2, characterized in that the bias of the check valve by mechanical means ( 13 . 14 . 15 ) is given. Micromixer according to claim 2, characterized that the check valve electrically, pneumatically, hydraulically or electromagnetically controllable is. Micromixer according to one or more of claims 1 to 4, characterized in that the Rückströmsperre as a membrane assembly is trained. Micromixer according to one or more of claims 1 to 5, characterized in that the Rückströmsperre by cleaning pins, which at each opening and closing process in the from the backflow barrier shared opening retract and are substantially needle-shaped, of Deposits are cleaned during operation. Micromixer according to one or more of claims 1 to 6, characterized in that entrance gaps ( 19 . 20 ) for the partial flows ( 6 . 7 . 37 ) are formed as narrow annular gaps, so that the partial flows ( 6 . 7 . 37 ) meet as thin film layers on each other. Micromixer according to one or more of claims 1 to 7, characterized in that the entrance slits ( 19 . 20 ) by microstructured components ( 16 . 9 ), a division of the partial flows ( 6 . 7 . 37 ) into individual partial beams. Micro mixer according to one or more of claims 1 to 8, characterized in that the outlet channel ( 11 ) has a smooth and expanding geometry. Micro mixer according to one or more of claims 1 to 9, characterized in that in the outlet channel ( 11 ) a feed for a jacket jet is provided, the mixed partial streams ( 6 . 7 . 37 ) enveloped when omitting. Micromixer one or more of claims 1 to 10, characterized in that the response pressure and / or the opening behavior the backflow stop, the width of at least one of the inflow column and / or a characteristic Dimension of mixing and Reaction zone with mechanical, hydraulic, pneumatic, electrical or Electromagnetic means are adjustable from the outside and / or as manipulated variables of an outer or inner Control loop can be varied automatically. Micromixer one or more of claims 1 to 12, characterized in that two or more valve mixer units according to the invention are arranged in a common housing with common supply of the partial flows and common outlet channel in such a way that they can be operated in parallel. Use of the micromixer after one or more the claims 1 to 13 for Precipitation / and / or Crystallization reactions, the production of nanoparticles, carbon nanotubes, fullerenes or particles / nanoparticles with several in concentric sequence arranged layers of different substances.