JP2008043892A - Mixer and reactor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mixer and a reactor capable of obtaining a sufficient production speed by compensating the defects of a static mixer and a dynamic mixer and obtaining a high yield by improving reaction efficiency. <P>SOLUTION: The mixer is used in a reaction system that performs a continuous processing and has a first mixing section 8 with a mixing channel 24 where at least two microchannels 22a, 22b interflow and a second mixing section 10 provided downstream the first mixing section 8. Further, the section 10 has a rotation-symmetric mixing space 2, a stirrer 26 that is rotated around a rotation-symmetric axis of the mixing space 2 in the mixing space, and a driving mechanism 28 that drives the stirrer 26. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mixer and a reaction apparatus suitable for continuous chemical reaction, particularly organic chemical synthesis.

  For example, when organic chemical synthesis is performed by reacting a raw material in which an organic solvent is dissolved and a water-soluble raw material, the two raw materials react at the interface of the two solvents. Therefore, the movement of the raw material molecules to the interface is a so-called diffusion-controlled reaction in which the reaction is rate-limiting. As a means for promoting such a reaction, a reaction device called a static mixer or a microchannel chip restricts the distance to the interface depending on the dimensions of the reaction vessel. Such a microchannel chip is easy to control the temperature and has a good yield, but it is not suitable as a mass production means because it performs a very small amount of processing.

  On the other hand, there is also known a method in which a liquid is forcibly stirred by a dynamic mixer to form a state in which two liquids are emulsified, and the reaction proceeds by increasing the interface ratio and decreasing the diffusion distance. For example, there is a batch type process in which a raw material is charged into a container and mixed with a stirring blade for a predetermined time. However, in batch processing, a relatively large container is used to obtain a desired product, sufficient stirring and mixing cannot be obtained, and detailed temperature conditions are difficult to set, resulting in a decrease in yield.

  Therefore, it is conceivable to employ a continuous processing apparatus in which a stirring bar is rotated in a relatively small container through which a fluid is continuously circulated. Patent Document 1 discloses a mixer using a stirring bar having a blade, and Patent Document 2 discloses a mixer using a bar-shaped stirring bar. However, in the techniques described in these documents, the particle refining effect due to the forced convection mixing effect is not necessarily sufficient for forming an emulsion necessary for the reaction, and the yield may be reduced.

JP-A-1-262936 JP 2001-9254 A

  The present invention has been made in view of the above circumstances, and can compensate for the disadvantages of static mixers and dynamic mixers to obtain a sufficient production rate and improve reaction efficiency to obtain a high yield. The object is to provide such a mixer and reactor.

  In order to achieve the object, the mixer according to claim 1 is a mixer used in a reaction system that performs continuous processing, and has a mixing channel in which at least two fine channels merge. And a second mixing unit provided downstream of the mixing unit, wherein the second mixing unit includes a rotationally symmetric mixing space and a rotational symmetry axis of the mixing space in the mixing space. And a drive mechanism for driving the stirrer.

  In the first aspect of the present invention, in the first mixing section, the raw material fluids flowing through at least two fine flow paths merge in the mixing flow path to perform mixing by diffusion, and in the second mixing section, mixing is performed. Convective mixing is performed by forced stirring with a stirring bar rotating around the rotational symmetry axis of the space. Thus, an efficient mixing action can be obtained by convectively mixing the fluid in a state of being at least partially diffused and mixed.

According to a second aspect of the present invention, there is provided the mixer according to the first aspect, wherein a plurality of the first mixing sections are arranged with respect to the second mixing section.
In the second aspect of the present invention, since a plurality of first mixing sections are arranged for one second mixing section, the first mixing section having a relatively low processing speed is relatively It is possible to balance the flow rate of the second mixing unit having a high processing speed.

The mixer according to claim 3 is the invention according to claim 1 or 2, wherein the mixing flow path is formed to be inclined with respect to the radial direction of the mixing space. .
In the invention according to claim 3, since the mixing channel is formed to be inclined with respect to the radial direction of the mixing space, it is possible to ensure a predetermined mixing channel length without changing the diameter of the device. it can.

A mixer according to a fourth aspect of the present invention is the invention according to any one of the first to third aspects, wherein the second mixing section has a lead-out flow path that opens on the axis of the mixing space, A narrow portion that prevents unstirred fluid from flowing out in a short circuit is formed between the opening of the outlet channel and the surface of the stirrer that faces the opening.
In the invention according to claim 4, in the second mixing portion, the unstirred fluid is short-circuited by the narrow portion formed between the opening of the outlet channel and the surface of the stirrer facing the opening. Outflow is prevented, and sufficient stirring action can be obtained.

A reactor according to claim 5 is a mixer according to any one of claims 1 to 4, a supply source for supplying a raw material fluid thereto, and a recovery container for recovering a reaction product in the mixer. It is characterized by having.
In the reaction apparatus according to the fifth aspect, the reaction product can be efficiently obtained by the mixing action by the mixer having the first mixing section and the second mixing section.

  According to the mixer of the first to fourth aspects, a sufficient production speed and a high yield can be obtained by compensating for the disadvantages of the static mixer and the dynamic mixer.

  According to the reaction apparatus of the fifth aspect, a high-quality reaction product can be obtained with high productivity by the high mixing action of the mixer.

  Embodiments of the present invention will be described below with reference to the drawings. In the following embodiment, since the reaction is caused by mixing to obtain a product, the mixer is a reactor at the same time, and the mixing system is a reaction system.

  1 (a) and 1 (b) show a mixer according to a first embodiment of the present invention, in which a main body 4 having a mixing space 2 formed at the center of a disk-shaped member is provided from below. A first mixing portion (static mixer portion) 8 having a mixing flow path where two fine flow paths merge together with a covering base portion 6 and a second stirring bar rotating in the central cylindrical mixing space 2. The mixing unit (dynamic mixer unit) 10 is configured. A temperature adjusting device such as a heater 12a is provided below the base portion 6, and the mixer is adjusted to a predetermined temperature by a temperature sensor 12b and a controller 12c. A cover 16 having a lead-out hole 14 is provided on the upper portion of the main body 4.

  First and second raw material fluid inlets (joints) 18a and 18b are respectively provided at two positions on the upper edge of the main body 4, and these are vertical introduction channels that pass through the main body 4 and open to the lower surface. It communicates with 20a, 20b and is connected to horizontal introduction flow paths 22a, 22b formed on the lower surface of the main body part 4. As shown in FIG. 2 (a), each horizontal introduction flow path 22a, 22b extends in the radial direction toward the center, then branches into two in the circumferential direction, and similarly extends from the other side in the intermediate portion. The two horizontal flow channels 22a and 22b are joined together to form two mixed flow channels 24 extending toward the center in the radial direction. These two mixing channels 24 constitute the first mixing unit 8.

The cross-sectional area of these channels is 1 mm ² or less, preferably 0.25 mm ² or less, more preferably 0.01 mm ² or less. The cross-sectional dimensions of the introduction flow paths 20a, 20b, 22a, and 22b are as follows: W ≦ H, where W is the width and H is the depth, as described in FIGS. It is desirable. In addition to these, the cross-sectional shapes of the introduction channels 20a, 20b, 22a, and 22b are selected every time depending on the target chemical reaction such as a rectangular shape or a semicircular shape.

  The mixing space 2 is a cylindrical space having a representative dimension (inner diameter) D of about 200 mm or less, and a stirrer 26 having a smaller outer diameter is inserted therein. If the size of the mixing space 2 is reduced, the ratio of the surface area to the volume of the fluid in the mixing space 2 increases, so that an effect of promoting temperature control and fluid mixing of the fluid in the container can be obtained. The representative dimension (inner diameter) D of the mixing space 2 is desirably 200 mm or less, more preferably 100 mm or less, and still more preferably 10 mm or less.

  In this embodiment, the stirrer 26 is a capsule-like member extending in a direction perpendicular to the axis of the mixing space 2 and is forcibly rotated around the axis of the mixing space 2 by the drive mechanism 28. The stirrer 26 is made of a magnetic material or a metal coated with a material having characteristics of an organic fluid-resistant material such as a tetrafluoroethylene polymer, ceramic, or glass. In the drive mechanism 28, the coil 30 is equally arranged on the same circumference in the base portion 6 and the main body portion 4, and an excitation current is input from the controller 32, and the coil 30 is sequentially magnetized with a polarity, Thereby, the stirring bar 26 is rotated.

  The shape and size of the stirrer 26 are selected so that the action of forming a turbulent flow by rotation can be exhibited. For example, the difference in the outer diameter of the stirrer 26 with respect to the inner diameter of the mixing space 2, that is, the radial gap effectively applies a shearing force to each introduced fluid by the rotation of the stirrer 26, thereby promoting mixing. Therefore, the thickness is desirably 1.0 mm or less, more desirably 0.5 mm or less, and further desirably 0.2 mm or less.

  In this embodiment, the outlet channel 34 for discharging the fluid from the mixing space 2 is formed in the upper part of the mixing space 2 along its axis. Thereby, as shown in FIG. 3, a narrowed portion G that is the narrowest portion in the flow path in the mixing space 2 is formed between the opening of the outlet flow path 34 and the stirring bar 26.

  In this way, by setting the narrow portion G between the stirring bar 26 having a non-uniform shape in the circumferential direction and the opening of the outlet channel 34, the mixing space 2 becomes a semi-sealed space and is stronger than the stirring bar 26. Even if convection occurs, a situation in which the unmixed fluid introduced from the mixing channel 24 flows to the outlet channel 34 in a short circuit is avoided, and as a result, the fluid that has undergone sufficient agitation flows out. In order to obtain such an effect, the narrow part G seems to be better as it is narrower. However, if it is too narrow, the flow resistance becomes excessive, a load is applied to the pump and the rotary drive device, and the quality is poor due to friction. Will happen. In order to obtain a sufficient stirring effect while avoiding these, the difference between the height H of the stirring bar 26 and the height h of the mixing space 2 is preferably 2.0 mm or less, more preferably 0.2 mm or less, and even more preferably. Is 0.05 mm or less.

  Hereinafter, an operation in the case of mixing two fluids that do not easily dissolve each other using the mixer configured as described above will be described. The two fluids are introduced from the respective inlets by the action of a pump or the like, and flow into the mixing channel 24 having a fine cross section through the introduction channel. Here, a part or all of the raw material fluids are mixed by the diffusion mixing at the interface between the two fluids in the mixing channel 24 before exiting the mixing channel 24. In this process, the fluid is adjusted to a predetermined temperature by the temperature adjusting means 12 such as the heater 12a.

  The fluid that is at least partially diffused and mixed is further introduced into the mixing space 2. In the mixing space 2, the fluid is stirred and sheared by forced convection by the stirring bar 26. As a result, the fluid that has not been mixed is refined into an emulsion state, and further mixed uniformly by the action of diffusion mixing.

  As described above, according to the present invention, in the first mixing section 8 having the mixing flow path 24 having a fine cross section, after a part or all of the raw material fluid is mixed, the forced convection mixing by the stirrer 26 is performed. By sending it to the mixing section 2, an efficient mixer that takes advantage of both the static mixer and the dynamic mixer is constructed.

  Note that the supply fluid is not limited to a liquid. For example, when one of the fluids is a gas, the bubbles that are torn off by a strong shearing force are microbubbled (fine bubbles) and are mixed in the mixing space 2. Evenly distributed. In the microbubble, since the bubble surface area with respect to the gas volume is dramatically increased, the reaction efficiency is improved.

  In this mixer, as the ratio (ds / D) of the diameter D of the mixing space 2 to the length ds of the stirrer 26 is closer to 1, scraping of each mixed supply fluid becomes more effective by the rotation of the stirrer 26. This effectively forms a thin layer of the supply fluid in the mixing space 2. As a result, the intermolecular distance between the supply fluids is also reduced, so that mixing by molecular diffusion is promoted. On the other hand, if this ratio is too small, the speed of the tip of the stirrer 26 becomes small, or the fluid flow becomes unsmooth and has an adverse effect.

The rotational speed of the stirrer 26 will be described. In this mixer, the introduction flow velocity V of the supply fluid is
V = (4 · Q) / (π · di ² ) Equation 1
(Q is the supply amount QA or QB of the supply fluid, di is the inner diameter of the mixing channel 24), and the peripheral speed Vc of the stirrer 26 is
Vc = π · ds · ω Equation 2
(Ds is the length of the stirrer 26). Here, if the relative (circumferential) speed, which is the difference between the flow velocity and the peripheral speed of the stirrer 26, increases, that is, if the ratio of the introduction flow rate / the peripheral speed of the stirrer 26 decreases, the mixture is introduced into the mixing space 2. The fluid layer of each supplied fluid is miniaturized, the fluid layer between the supplied fluids becomes thinner, and the number of layers of the supplied fluid in the mixing space 2 increases. Thereby, the intermolecular distance between the supply fluids is also reduced, so that mixing by molecular diffusion is promoted. It is desirable that the ratio of the supply fluid introduction speed / the peripheral speed of the stirrer 26 is 1/3 or less, more preferably 1/5 or less, and even more preferably 1/8 or less.

  In the illustrated example, by forming the stirrer 26 with a smooth curved surface, smooth rotation and flow can be ensured even if the dimensional difference is reduced. In order to obtain the same effect, the volume ratio between the volume of the mixing space 2 and the volume of the stirrer 26 (26 volumes of the stirrer / 2 volumes of the mixing space) may be reduced, but if the dimensional difference increases, a stagnation region is formed. End up. In order to reduce the dimensional difference and the volume ratio, the flatness ratio (= h / w) of the stirrer 26 may be set larger than 1. However, the remotely driven stirring as in this embodiment is performed. A child 26 and a simple rod shape is difficult because the posture becomes unstable. It can be employed in the case of a radial stirrer 26 extending in three or more directions as described later, or a system directly driven by a drive shaft.

  The volume ratio of the volume of the mixing space 2 to the volume of the stirrer 26 must be selected optimal for the target reaction. For example, if the volume ratio (rotary body volume / mixing chamber volume) is decreased in the precipitation-type reaction, it is possible to suppress the stop of the stirrer 26 due to the stay of the precipitate in the mixing space 2. The volume ratio is preferably 5% to 80%, more preferably 15% to 60%, and even more preferably 20% to 40%, but it is needless to say that the optimum value is selected according to the target chemical reaction in a timely manner. No.

  Another factor that is important in controlling the mixing state is the passage time of the fluid in the mixing space 2 as a whole. This can be adjusted by the supply pressure of the fluid, the degree of restriction in the introduction flow path 20 and the discharge flow path 34, and the like. Accordingly, the inner diameters di and de of the mixing channel 24 and the outlet channel 34 must be set so that sufficient mixing or a reaction time associated therewith can be obtained.

  If this passage time is T, the number of layers of the supply fluid in the mixing space 2 is related to the product (ω · T) of the rotational speed ω per unit time of the stirrer 26 and time T. Here, the thickness of one layer is a function of a value obtained by dividing the mixed space 2 diameter D by the number of layers. Thereby, in the mixer according to the present invention, the smaller the mixing space 2 diameter D and the larger the rotation speed ω of the stirrer 26, the finer the fluid layer of the supply fluid in the mixing space 2, and the smaller D becomes, The residence time of the supply fluid in the mixing space 2 is reduced, so that an effective mixing is achieved in a short time. The inner diameter of the supply fluid introduction channel and the mixed (reaction) product outlet channel 34 formed in the main body 4 and the base unit 6 is φ8.0 mm or less, and more preferably φ1.0 mm or less. Is desirable.

  As mentioned above, the mixing action in the mixer according to the invention is governed by complex factor combinations. Among these are the supply of fluid, the discharge speed, the viscosity of the fluid, the mixing ratio of the supply fluid, the type of reaction and product that occur as a result of mixing. In particular, the remotely-driven stirrer 26 as in this embodiment has an advantage of preventing fluid contamination by the drive mechanism 28, but it is also difficult to completely control the rotation speed of the stirrer 26. Therefore, it is desirable to try the shape, size, and other conditions of each part of the apparatus for each mode of mixing or reaction treatment and adopt the optimum one. In the following, various variations of this device will be described.

  FIG. 4 shows a modification of the shape of the stirrer 26. FIG. 4A shows a capsule type in which both ends are hemispheres and the center is a cylindrical shape, FIG. 4B shows a cylindrical shape, and FIG. 4C shows a prismatic shape. Further, (d) shows a capsule type, (e) shows a columnar shape, and (f) shows a prismatic shape made into a cross shape. These have radial portions 40 each having an axis extending in a direction perpendicular to the rotation axis (axis of the mixing space 2). The cross-sectional shape of the radial portion 40 is not limited to the above example, and any curved or linear shape can be adopted. For example, the curved shape includes a circle, an ellipse, or an appropriate quadratic or cubic closed curve, and the linear shape includes an arbitrary polygon including a triangle. Of course, a mixed shape of a curved shape and a linear shape may be used. For example, as described above, a vertically flat ellipse is difficult to employ because it falls down in the types (a) and (b), but may be employed in the types (d) and (e).

  Moreover, the number of the radial parts 40 is not restricted to the case of 2 and 4 shown above, A suitable number can be employ | adopted. It is not necessary to make the shape, length and other dimensions of the radial portions 40 the same. For example, one direction that intersects in (e) may be shortened. This is because actions such as ensuring the stability of the posture can be obtained. Moreover, although the radial part 40 of (a), (d) is not an equal cross section along the axis line, others are isotropic along an axis line, and it is clear that either may be sufficient. It is desirable that the corners are appropriately chamfered (rounded).

  FIG. 5 shows a mixer according to another embodiment in which the structure of the narrow portion G is devised. In this embodiment, the enlarged diameter portion 64 is formed at the base of the outlet channel 34, and the protrusion 62 having a shape corresponding to this is formed on the stirrer 26. Thereby, the narrow part G can be formed accurately and a centering function for maintaining the rotation center of the stirrer 26 can be provided.

  In the example of FIG. 6A, the shape of the confluence is not a T-junction, but a Y-junction, whereby the mixing channel 24 is set short. The length of the mixing channel 24 can be changed by changing the angle of the oblique channel. The length may be set appropriately according to the reaction.

  Further, in the example of FIG. 6B, the inclined flow path 60 reaching the mixing flow path 24 is branched so that the merging is performed in multiple stages. Thereby, the reagent introduced into the mixing space 2 becomes multi-layered, and each fluid layer becomes thin. Accordingly, since the distance between the raw material fluids is also reduced, mixing is promoted by the effect of improving the mixing efficiency by molecular diffusion.

  Further, FIGS. 6C and 6D are modified examples for securing the length of the mixing channel 24. Thus, the length of the mixing channel 24 can be increased without increasing the size of the disk-shaped body by inclining the mixing channel 24 with respect to the radial direction of the mixing space 2 or by making it curved. Can do.

  FIG. 7 shows still another embodiment of the present invention, in which a larger number of mixing channels 24 are merged into one mixing space 2. In this embodiment, in order to form many mixing channels 24, a distribution channel for distributing one raw material fluid is formed on a different plane from the mixing channel 24.

  That is, as shown in FIG. 8 (a), a mixing channel 24 is formed on the lower surface of the main body portion 4, and the upper surface of the base portion 6 has an annular first as shown in FIG. 8 (b). The distribution channel 66a is formed. Then, another second base portion 68 is provided below the base portion, and as shown in FIG. 8C, an annular second distribution channel 66b is formed on the upper surface of the second base portion. In addition, the raw material fluid is supplied to the horizontal introduction flow channel on the same plane as the mixing flow channel 24 through the through hole 70 formed at the predetermined location.

  Thereby, since the distribution flow paths 66a and 66b and the mixing flow path 24 are on different surfaces, these flow paths do not interfere with each other, and the raw material fluid can be supplied to three or more mixing flow paths 24. . In this way, by mixing a large number of mixing channels 24 with respect to one mixing space 2, the mixing speed of the first mixing unit 8 and the second mixing unit 10, that is, the reaction amount can be balanced. .

  FIG. 9 shows a modification for making the length of the mixing channel 24 longer. FIG. 9A shows an example in which the mixing channel 24 is inclined with respect to the radial direction. ) Is obtained by further forming the mixing channel 24 in a curved (spiral) shape. By doing in this way, the long mixing flow path 24 can be formed by the main-body part 4 of the same magnitude | size.

  As temperature control means, instead of the heater 12a, a heat medium flow path for flowing the heating or cooling medium M is formed in the base portion 6, and the temperature sensor 12b is installed at a position where the temperature of the mixing space 2 is detected. May be. By providing a flow rate adjustment valve that adjusts the flow rate of the heating or cooling medium and controlling it with the controller based on the indication value of the temperature sensor, it is possible to achieve optimal temperature control for chemical reaction and perform chemical reaction with high efficiency It becomes.

  In the present invention, the internal pressure of the entire container can be increased in addition to the temperature by increasing the line pressure in the pump that pumps the supply fluid. By placing pressure sensors at appropriate positions in each flow path or in the mixing chamber where pressure can be detected, pressure control based on the signals is performed, so that optimum pressure conditions according to the target reaction process can be obtained. Can be set.

  Moreover, you may install an analyzer in a mixer and the downstream flow path. The analysis device is a device that analyzes the components of the mixed (reaction) product, such as a device that analyzes the components of the mixed (reaction) product, such as a chromatography device. Thereby, the components of the product after mixing (reaction) are sequentially analyzed, and the analysis results (yield, etc.) are output to the controller in real time. Based on this analysis result, the controller makes a determination based on a predetermined determination criterion, outputs a control signal for the motor speed and the temperature of the heater 52 to the motor and the heater 52, and the component (yield) of the target product is the maximum value. Alternatively, these can be controlled so as to become target values.

  In the mixer in the above-described embodiment, when the mixing space 2 is maintained, if the disk-shaped member is sequentially disassembled and removed, maintenance such as changing the size or shape of the flow path or cleaning the mixing space 2 can be performed. Is possible. Similarly, the assembly after the maintenance is very simple, and only the disk-shaped members are coupled. Therefore, the mixer is easier to maintain and manage than the existing microreactor.

BRIEF DESCRIPTION OF THE DRAWINGS It is the (a) external appearance perspective view and (b) sectional drawing which show the mixer of embodiment of this invention. (A) is an arrow line view along the A line of FIG.1 (b), (b) and (c) are figures which show the cross-sectional shape of a flow path. It is a figure which expands and shows the part of the mixing space of FIG.1 (b). (A) thru | or (f) is a figure which shows the various modifications of a stirring element. (A) And (b) is a figure which shows the modification of the narrow part of embodiment of FIG. (A) thru | or (d) is a figure which shows the various modifications of a mixing channel. (A) And (b) is a figure which shows the mixer of other embodiment. (A) thru | or (c) are the arrow directional views along A, B, and C line | wire of embodiment of FIG. 7, respectively. (A) And (b) is a figure which shows the modification regarding the mixing flow path of embodiment of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Mixing space 4 Main-body part 6 Base part 8 1st mixing part 10 2nd mixing part 12 Temperature control means 12a Heater 12b Temperature sensor 12c Controller 14 Derivation hole 16 Cover 18a, 18b Introduction port 20a, 20b Vertical introduction flow path 22a , 22b Horizontal introduction flow path 24 Mixing flow path 26 Stirrer 28 Drive mechanism 30 Coil 32 Controller 34 Derivation flow path 38 Controller 40 Radial part 60 Inclined flow path 62 Protruding part 64 Diameter expansion part 66a, 66b Distribution flow path 68 Second Base part 70 Through hole G Narrow part

Claims (5)

A mixer used in a reaction system that performs continuous processing,
A first mixing unit having a mixing channel in which at least two fine channels merge;
A second mixing section provided on the downstream side of the mixing section,
The second mixing section includes a rotationally symmetric mixing space, a stirring bar that rotates about a rotationally symmetric axis of the mixing space in the mixing space, and a drive mechanism that drives the stirring bar. Mixer.   The mixer according to claim 1, wherein a plurality of the first mixing units are arranged with respect to the second mixing unit.   The mixer according to claim 1 or 2, wherein the mixing channel is formed to be inclined with respect to a radial direction of the mixing space.   The second mixing unit has a lead-out flow path that opens on the axis of the mixing space, and an unstirred fluid flows between the opening of the lead-out flow path and the surface of the stirrer facing the opening. The mixer according to any one of claims 1 to 3, wherein a narrow portion for preventing short-circuit outflow is formed. 5. A reaction apparatus comprising: the mixer according to claim 1; a supply source for supplying a raw material fluid to the mixer; and a recovery container for recovering a reaction product in the mixer. .

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