WO2003089129A1 - Integrated mixing and switching system for microreactor technology - Google Patents

Abstract

The invention relates to ceramics and concerns a system for microreactor technology, i.e. one which can be used in microreactors for example. The aim of the invention is to provide a system enabling the supply of individual fluid components to be regulated and discontinued. This is achieved by means of an integrated mixing and switching system for microreactor technology, comprising an upper part, a lower part and an insert part, in addition to two supply elements and an outlet which are spatially connected to an antechamber which is respectively located in another part, and wherein a spatial connection is produced from the antechamber to one or several cavities, and the cavities are spatially connected either to outlets or to a post-chamber. The connection to one or several supply elements and/or outlets is produced or discontinued by displacing or rotating the insert part.

Description

 Integrated mixing and switching system for microreaction technology

Field of application of the invention

The invention relates to the fields of ceramics, chemistry, medicine, pharmacy, biology, genetic engineering and microreaction technology and relates to an integrated mixing and switching system for microreaction technology, as used for example in microreactors for synthesizing active substances or hazardous substances or for catalyst screening can come.

State of the art

Microreactors are becoming increasingly important due to their advantages compared to macroscopic chemical reactors. Your advantages include shorter response times, lower chemical consumption, less space, lower manufacturing and operating costs as well as the possibility of system integration. Micromixers, in which chemical reactions can be carried out, form a main component of the microreactors. A homogeneous mixing of liquid or gaseous reactants that takes place over a short period of time is a basic requirement for the course of a desired chemical reaction.

While in macro systems an intensive mixing of two components can be brought about mainly by convection, assisted by stirring or shaking, the most effective mechanism of action in micromixers is diffusion, since the reactants show laminar flow movements due to the low Reynolds number.

Most static micromixers use the principle of multilamination to ensure fast, diffusion-driven mixing of the components.

WO 99/20379 describes a static micromixer for mixing liquid, viscous or gaseous phases, consisting of an upper and lower part of the housing, which lie close together at the connecting surfaces. Two inlets and one outlet open into this parting plane. The mixing section for the phases to be mixed form channel grooves which are cut out in one of the two connecting surfaces and which intersect several times. A disadvantage of this invention is the temperature control of the reaction mixture, which takes place exclusively via the housing parts.

Another version of a static mixer is described in WO 00/78438. This micromixer consists of a mixing chamber with an upstream guide component for the separate supply of fluids to be mixed or dispersed. The guide part is crossed with slot-shaped channels running obliquely to the longitudinal axis of the micromixer, which cross alternately without contact and open into a mixing chamber, from which they run into a common outlet cross section.

A micromixer also consisting of a mixing chamber and an upstream guide component is presented in DE 197 48 481 A1, the guide component consisting of grooved foils of at least two types, each of which forms a family of channels for guiding the fluids to be mixed when layered on top of one another. The grooves of at least one type of film have different lengths with an arcuately curved section, and the wall thicknesses of the webs between the longer grooves are at a smaller distance than between the shorter grooves, which should result in an equally high mixing effectiveness over the entire end face.

DE 199 61 257 A1 describes a micromixer in which the feed elements are wedge-shaped plates which can be assembled into a ring sector which surrounds the mixing chamber in an arc. The microchannels provided for each fluid form symmetrical cascades comprising at least two stages. This micromixer should be distinguished by a particularly simple and compact design and have the advantage that identical volume flows are present at the outputs of the microchannels for each fluid.

An active microfluidic mixer for mixing microparticles and fluids is described by Jin-Woo Choi [Jin-Woo Choi et al., Microfluidic Devices and Systems III, Eds. Carlos H. Mastrangelo, Holger Becker, Proceedings of SPIE Vol. 4177 (2000), pp. 154-161], which is based on electrohydrodynamic convection. A liquid in which microparticles are dispersed is brought into contact with a second reaction liquid. An external electrical field forces the charged particles in the liquid to move. The particle movement exerts a shear effect on the surrounding liquid and pulls part of the liquid with it. In this way, convective mixing of both liquids is brought about. The

Mixing speed is determined by the parameters of the applied electric field, the electrical conductivity and the electrode geometry. The obvious disadvantage of this mixing system is that charged microparticles are required for electrohydrodynamic convection to occur. Mixing pure liquid phases is not possible in this way.

A switchable dynamic micromixer described in WO 99/01209 can also be mentioned as prior art. This mixer has a mixing chamber, inside which there are several magnetizable beads, which are covered on one side by a cover, but can move freely, and the total length of which is defined in a linear, adjacent row slightly below the smallest lateral mixing chamber dimension. A switchable rotating magnet system then enables a common rotation of the linear bead structure and thus ensures a stirrer function.

A disadvantage inherent in all the static and dynamic mixing systems described is that no system-internal switching enables metering or switching off of the reactants. A metering of the components or the interruption of the supply of the reactants can only take place outside of the feeds to the mixer. Furthermore, these mixing systems can only be partially tempered. In these cases, temperature control takes place directly over the entire housing. A segmental temperature control in the area of a dwell section before or after the onset of the desired chemical reaction is not mentioned. State the nature of the invention

The object of the invention is to provide an integrated mixing and switching system for microreaction technology, with which the supply of individual fluid components can be both regulated and switched off.

The object is achieved by the invention specified in the claims. Further training is the subject of the subclaims.

The integrated mixing and switching system according to the invention for microreaction technology consists of an upper part, a lower part and an insert part, of which the upper and / or the lower part has at least one recess for the insert part, and the upper part and lower part are sealingly connected to the intermediate part , In the lower part and / or in the upper part or on one or both sides of the insert part, at least two inlets and at least one outlet are each arranged in the form of recesses and each for liquids or gases. The inlets end in a sack-like manner and are spatially connected to an anteroom which is designed in the form of a recess and which is located in the respective other part, which forms a parting plane with the part in which the inlets and / or the outlet are arranged. A connection to one or more cavitates is established from this room. The cavities are either spatially connected to the one or more outlets or end in a neighboring space, which is likewise designed in the form of a recess and connects to one or more outlets, which are then arranged in the respective other part, which is connected to the part, in which the next room is arranged, forms a dividing plane. By shifting and / or rotating the insert, the connection to even one feed or one outlet is established or interrupted.

The top part, the bottom part and the insert part advantageously consist of the same or different materials, for example of plastic or metal or preferably of ceramic. Furthermore advantageously, the recess in the upper part and / or lower part is round and the insert part has a round circumference.

The anteroom and / or the anteroom, in which the feeds and / or outlets end, is likewise advantageously kidney-shaped or bean-shaped or oval or slot-shaped.

Furthermore, it is advantageous if, in the case of the arrangement of the antechamber and / or the antechamber in the insert, the antechamber and / or the antechamber are designed in the form of a passage opening.

It is also advantageous that the feeds end at the outer areas of the anteroom and / or the anteroom and the connection with the cavities is arranged in the middle of the anteroom and / or the anteroom.

Furthermore, it is advantageous that the connection of the anteroom or anteroom is interrupted by a feed or an outlet by rotating or moving the insert.

A further advantageous variant of the invention is if the connection of the antechamber or the antechamber with alternating one and the other feed or one or the other outlet is realized by mutual movement of the insert.

It is also advantageous that the cavities are surrounded by a heating or cooling system, which have a separate inlet and outlet from the insert part and / or upper part and / or lower part.

It is also advantageous that the heating or cooling system is guided in parallel with the cavities and / or inlets and / or outlets in the upper part and / or lower part and / or insert part and the temperature is controlled by heat exchange.

It is also advantageous that the surfaces of the upper part, the lower part and the insert part lie sealingly at least in the edge area. Furthermore, it is advantageous if the insert part is connected to a lever which can be operated from outside the closed upper part and lower part and enables the movement of the insert part.

The insert part and / or the lever advantageously consist of a ferromagnetic material, as a result of which the movement of the insert part is realized via electromagnetic operation.

The insert part and / or the lever advantageously also consist of a non-ferromagnetic material, as a result of which the movement of the insert part is realized by mechanical operation.

The insert and / or the lever advantageously also consist of a piezoceramic material, as a result of which the movement of the insert is realized via piezoelectric operation.

It is also advantageous if the insert is operated hydraulically or pneumatically.

The integrated mixing and switching system for microreaction technology according to the invention provides a mixing and switching system, in particular for microreactors and micromixing systems, which regulates the supply and / or discharge of individual components or reactants in gaseous or liquid form in terms of time, quantity, concentration, etc. and can also be switched on and off. This can be done via mechanical, electromagnetic, piezoelectric, hydraulic or pneumatic operation.

In this way it is possible, for example, to rinse the reactor space with only one component or to control the formation of a desired reaction product by regulating the inflow of a reactant. A further possibility of the invention consists in that for the system serving as mixer and reactor, in addition to the already known possibility of temperature control of the overall system, also a section, zone or segment Temperature control is possible, and that, for example, preheating of a reaction mixture or cooling of a reaction product can be ensured in one system section.

The functioning of the integrated mixing and switching system according to the invention is as follows. Two or more fluids enter the inlet openings provided for this purpose in the system and are guided spatially separated from one another into, for example, channel-like cavities which end in a sack-like manner. The merging of the fluids is now only possible by entering an antechamber, which is located as a recess in the other part, which forms a parting plane with the part with the channel-like cavities. By moving or rotating the insert part, the mutual supply of one or more fluids simultaneously or successively into the anteroom is possible, since the spatial connection between the anteroom and one or more channel-like cavities can be established simultaneously or in succession by the movement of the insert part. It is also possible to block the spatial connection of the anteroom with all channel-like cavities.

The anteroom in turn creates the spatial connection to one or more cavities. The cavities can be in or on all parts within the system.

The cavities are then spatially connected to at least one outlet or one or more or all of them end in a neighboring room. This secondary space enables the products from the cavitation (s) to enter one or more outlets which are located as recesses in the other part, which forms a parting plane with the part of the secondary space. The outlets can also be designed as channel-like cavities.

The cavities can be meandering or intersecting several times or branching multiple times and / or with a larger space, for example a reaction space, or in the form of a two-dimensional nozzle structure or as a fluid switching structure.

Due to the possibility of arranging through openings in the insert, which can serve as ante and / or post space, a change in the use of cavities from the upper part to the lower part and vice versa can be achieved. The mixing and switching system according to the invention makes it possible, for example, to supply peripheral analysis devices, sample collectors or further mixing and / or reaction sections with the fluid mixture or reaction product produced.

Best ways to design the invention

The invention is explained in more detail using an exemplary embodiment.

A microreactor consists of a lower part, an upper part and an insert. The lower part has two feeds for the educts and an outlet for removing the mixture and / or a reaction product as well as an inlet and an outlet for a temperature control medium in the form of water. The lower part also has a mixing and / or reaction chamber in which both educt fluids meet, are mixed with one another or react with one another. This mixing and / or reaction chamber opens into a meandering channel structure that leads to the outlet. This channel structure is designed in such a way that the mixing process is intensified by narrow channel geometries <500 μm and thus shortened diffusion paths. At the same time, a channel is led from the inlet of the temperature control medium to the outlet parallel and without contact to the channel structure of the mixture and / or the reaction mixture, so that heat can be exchanged between the temperature control medium and the fluid mixture or reaction product via the separating wall between the two channel structures. In this way, internal heating of a reaction mixture or internal cooling of a reaction product is achieved. An additional temperature control of the microreactor is possible via the housing parts, as is often described as prior art. A channel structure between the mixing and / or reaction chamber and the outlet, in addition to intensifying the mixture, at the same time allows a dwell section for preheating, reaction temperature control or cooling of a product or a starting material mixture. The fluid inlets end in a bean-shaped sack structure, which have no connection to the mixing and / or reaction chamber in this plane. The upper part lies sealingly on a connecting surface in the edge area on the lower part and has a round recess which serves to receive and guide the round insert part. For one mechanical movement of the insert in the guide, a slot-shaped opening is left in the edge region of the upper part, through which a mechanical lever of the insert protrudes outwards. The insert part is slidably but laterally sealed in the guide of the upper part and lies sealingly but also slidably on the structured lower part. The sealing between the superimposed connection surfaces is carried out by compressive forces, namely pressing together the finely machined surfaces and / or seals, for example plastic or metal foils. A non-continuous recess is provided in the side of the insert facing the lower part. This recess enables the bean-shaped sack structure to be covered simultaneously with the mixing and / or reaction chamber. In this position of the insert, the educts from the feeds can meet in the recess of the insert by changing levels and can mix or react turbulently in the recess and the mixing and / or reaction chamber. Since the reaction chamber opens into the channel structure, the educt mixture is fed to a more intensive mixture and the reaction product is fed to a residence zone. The ratio of the inflow of the fluids is varied or the supply of a fluid is completely prevented by moving or rotating the insert. In this way, a reaction can be stopped internally or the desired reaction can be controlled. Flushing the microreactor with only one fluid is also possible in this way.

The microstructuring can be carried out using known methods suitable for the corresponding material class. For sintered ceramics, for example, laser processing, the eroding process and special micromechanical processes are possible. The shaping of the ceramic in the unsintered state can be done using special impression techniques, e.g. B. on slip presses, film casting, centrifugal casting, sol-gel casting, high and low pressure injection molding and freeze casting.

Claims

claims 1. Integrated mixing and switching system for microreaction technology, consisting of an upper part, a lower part and an insert, of which the upper and / or the lower part has at least one recess for the insert, and the upper part and lower part sealingly connected to the intermediate part are, and the lower part and / or the upper part or one or both sides of the insert have at least two inlets and at least one outlet, each for liquids or gases and each in the form of recesses, the inlets ending in a sack and these ends spatially with a Anteroom are connected, which is designed in the form of a recess and is located in the other part, which forms a parting plane with the part in which the recesses for the feeds and / or the or the outlets are located, and in which of the Vestibule a spatial connection to one or more cavities is established, un d the cavitates are either spatially connected to one or more outlets or to a neighboring space, which is also designed in the form of a recess and establishes the spatial connection to one or more sack-like outlets which are arranged in the other part, which is connected to the Part, in which the post space is arranged, forms a parting plane, and wherein the connection to one or more inlets and / or outlets is established or interrupted by displacement and / or rotation of the insert. 2. Integrated mixing and switching system for microreaction technology according to claim 1, wherein the upper part, the lower part and the insert part consist of the same or different materials. 3. Integrated mixing and switching system for microreaction technology according to claim 2, wherein the upper part, the lower part and the insert part consist of plastic, metal or ceramic. 4. Integrated mixing and switching system for microreaction technology according to claim 1, in which the recess in the upper part and / or lower part is round and the insert part has a round circumference. 5. Integrated mixing and switching system for microreaction technology according to claim 1, in which the anteroom and / or anteroom, in which the feed ends and the outlets begin, is kidney-shaped or bean-shaped or oval or slot-shaped. 6. Integrated mixing and switching system for microreaction technology according to claim 1, in which, in the case of the arrangement of the anteroom and / or after room in the insert, the anteroom and / or after room is in the form of a passage opening. 7. Integrated mixing and switching system for microreaction technology according to claim 1 and 4, in which the feeds end at the outer regions of the anteroom and / or the anteroom and the connection with the cavitates are arranged in the middle of the anteroom and / or the anteroom. 8. Integrated mixing and switching system for microreaction technology according to claim 1 and 5, in which the connection of the anteroom or anteroom is interrupted by a feed or an outlet by rotating or moving the insert. 9. Integrated mixing and switching system for microreaction technology according to claim 1, in which the connection of the antechamber and / or the antechamber with alternating one and the other feed and / or one or the other outlet is realized by mutual movement of the insert. 10. Integrated mixing and switching system for microreaction technology according to claim 1, wherein the cavities are surrounded by a heating or cooling system, which have a separate inlet and outlet from the insert and / or upper part and / or lower part. 11. Integrated mixing and switching system for microreaction technology according to claim 1, in which the heating or cooling system are performed in parallel with the cavities and / or inlets and / or outlets in the upper part and / or lower part and / or insert and the temperature control Heat exchange takes place. 12. Integrated mixing and switching system for microreaction technology according to claim 1, in which the surfaces of the upper part, the lower part and the insert part lie sealingly at least in the edge region. 13. Integrated mixing and switching system for microreaction technology according to claim 1, in which the insert is connected to a lever that can be operated from outside the closed upper part and lower part and enables the movement of the insert. 14. Integrated mixing and switching system for microreaction technology according to claim 1, in which the insert and / or the lever consist of a ferromagnetic material, whereby the movement of the insert is realized via electromagnetic operation. 15. Integrated mixing and switching system for microreaction technology according to claim 1, wherein the insert and / or the lever consist of a non-ferromagnetic material, whereby the movement of the insert is realized via mechanical operation. 16. Integrated mixing and switching system for microreaction technology according to claim 1, wherein the insert and / or the lever consist of a piezoceramic material, whereby the movement of the insert is realized via piezoelectric control. 17. Integrated mixing and switching system for microreaction technology according to claim 1, in which the movement of the insert is realized via hydraulic or pneumatic operation.