JP2005152727A - Extruder type continuous reactor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extruder with a micro-reactor function in order to cause a chemical reaction of powder and a solid material. <P>SOLUTION: The extruder type continuous reactor comprises a barrel, a plurality of screws installed inside the barrel and a micro-reactor part to cause a chemical reaction of raw materials carried by a plurality of the screws in the barrel, wherein the micro-reactor part is a void part formed by the outer peripheral face of a stop ring installed at the downstream of the screws and the inner peripheral face of the barrel. The stop ring which constitutes the micro-reactor has a catalytic function. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an extruder type continuous reaction apparatus, and more particularly to an extruder type continuous reaction apparatus provided with a microreactor function.

A reactor that is currently widely used for industrial applications is a batch reactor. This is a device having a double jacket structure and reacting while heating the reaction target with steam or the like while stirring the raw material charged inside with a stirring blade or the like.
However, this reaction kettle has problems such as when the viscosity of the reaction object such as raw materials and reaction products is high, the temperature cannot be uniformly controlled during the reaction, uniform stirring cannot be performed, and the product takes time to be taken out. . In addition, there is a problem in that the reaction vessel is made of glass in the experimental apparatus for the reaction and cannot be applied to a reaction in which the amount of substance changes before and after the pressure change or the reaction.
For this reason, it is conceivable to use a biaxial extruder or kneader as an apparatus for continuously processing such high-viscosity raw materials and products.

However, when a conventional biaxial extruder or kneader is used as a chemical reaction device, it is particularly possible to carry out chemical reaction of raw materials continuously while carrying powder, high-viscosity raw materials with a screw, uniform mixing, etc. It was difficult and was not considered.
On the other hand, as a mixing reaction apparatus used in an automatic chemical analyzer, a first flow path for flowing a first sample liquid provided with a liquid feeding means and a second sample liquid provided with a liquid feeding means are flowed. A second flow path, a mixing chamber for ejecting and mixing the first sample from a plurality of minute nozzles into the second sample, and a first chamber for discharging the sample mixed in the mixing chamber A mixing reaction apparatus having three flow paths is known (see Patent Document 1).
However, this mixing reaction apparatus is an apparatus for jetting and mixing the first sample into the second sample from a plurality of minute nozzles, and does not mix the first and second samples at the same time. . When the viscosity of the reaction raw material is high, quantitative supply is difficult, the diffusion coefficient is lowered, and uniform reaction cannot be performed in a short time. Further, it cannot be applied to chemical reactions of powders or solid materials.
JP-A-6-226071

  The problem to be solved by the present invention is that in a microreactor, there is no method for continuously reacting powder raw materials and high viscosity raw materials that cannot be used as raw materials.

The extruder type continuous reaction apparatus of the present invention includes a barrel, a plurality of screws installed in the barrel, and a microreactor unit that chemically reacts raw materials conveyed by the plurality of screws in the barrel. The microreactor portion is a gap formed by an outer peripheral surface of a stop ring provided on the downstream side of the screw and an inner peripheral surface of the barrel.
Moreover, the stop ring which comprises a microreactor part has a catalyst function, It is characterized by the above-mentioned.
Further, the clearance between the outer peripheral surface of the stop ring and the inner peripheral surface of the barrel constituting the extruder type continuous reaction device is 0.3 mm or less.
In addition, a kneading disk is disposed upstream of the microreactor section.
Further, a needing disk is disposed on the downstream side of the microreactor section, and the kneeing disk has an apex angle with respect to the top surface of the needing disk of 0 ° or more and within 5 °, that is, the needing disk is It has a flat plate shape with a certain thickness, or the width of the top surface is slightly thinner than the width of the center of the kneading disk, and the clearance between the top surface and the barrel is 0.3 mm or less. To do.
Moreover, the extruder which comprises a continuous reaction apparatus is a biaxial extruder, and the said screw consists of a double-supported structure which pivotally supports the rotating shaft of this screw shaft in a downstream tip part.
In the present invention, the upstream side of the microreactor section refers to the raw material supply side to the extruder, and the downstream side refers to the product discharge side obtained by the reaction of the raw materials.

  In the extruder type continuous reaction apparatus of the present invention, since the microreactor part is a gap formed by the outer peripheral surface of the stop ring and the inner peripheral surface of the barrel, the microreactor part is formed while maintaining the accuracy of the extruder. be able to. The microreactor part is pulverized, dispersed, and melted so that it can react under the operating conditions such as barrel temperature, feed amount, screw rotation speed, etc. Can be chemically reacted.

An embodiment of the continuous reaction apparatus of the present invention will be described with reference to FIG. FIG. 1 shows a sectional view of a biaxial extruder type continuous reaction apparatus.
The continuous reaction apparatus 1 is a biaxial extruder type continuous reaction apparatus having a barrel 2, two screws 3 and 3 arranged in parallel in the barrel 2, and a microreactor section 4 for chemically reacting raw materials. It is.
The barrel 2 has an eyebrow shape in a cross-sectional view perpendicular to the screw shaft, and two screws 3 and 3 are provided in the eyebrow shape. The two screws 3 and 3 may be rotated in the same direction or in different directions.

An example of the configuration of the screws 3 and 3 is shown in FIG. FIG. 2 is a perspective view of the screw, FIG. 2 (a) is a view showing a screw shaft core and a state in which a coupling body is fitted to the shaft core, and FIG. 2 (b) shows the screw after fitting. The screw 3 is composed of a connecting body of a screw 5, a kneading disk block 6, and a stop ring 7 that are fitted to the screw shaft core 3a.
The screw 5 includes a forward screw that advances the raw material in the barrel from the supply unit 2a or a reverse screw that moves backward. Further, the kneading disk block 6 can control the degree of kneading and shearing the reaction object in the barrel by combining a plurality of kneading disks having the same or different thickness with different phases.
The stop ring 7 is provided on the downstream side of the screw. As shown in FIG. 3, a gap 4a is formed by the outer peripheral surface 7a of the stop ring 7 and the barrel inner peripheral surface 2c. The gap portion 4a and the gap portion between the stop rings become the microreactor portion 4 that chemically reacts the raw material conveyed by the screw.

The screw reactor diameter direction cross section (AA cross section) of the microreactor part 4 is shown in FIG. 3, and the BB cross section is shown in FIG. The clearance for forming the gap 4a is preferably 100 μm to 1000 μm, more preferably 200 μm to 500 μm. The width L of the stop ring 7 is 6 mm to 20 mm when the barrel inner diameter is 80 mm to 160 mm, and incorporates one or more sets of stop rings.
Since the machining accuracy of the stop ring is several tens of μm even when surface processing distortion is applied, the clearance can be maintained at 100 μm to 1000 μm. Further, the raw material in the chemical reaction functions as a lubricant and is in a liquid friction state, and the air gap 4a is formed by floating around the shaft core by high-speed rotation of the stop ring. Clearance is almost the same clearance on the circumference.
Further, by adopting a double-supported structure that supports the rotating shaft of the screw shaft, the weight deformation of the shaft due to gravity is reduced.

When passing through the microreactor section 4, the raw material is in a molten state simultaneously with kneading, and a chemical reaction by molecular contact proceeds.
In a conventional microreactor, the reaction proceeds in a laminar flow state. In the microreactor using the stop ring of the present invention, a turbulent element is added due to the rotation of the shaft in the stop ring and the step difference of the stop ring, and the reaction proceeds effectively.

When the activation energy of the chemical reaction is low and the reaction is exothermic, for example, in the neutralization reaction, the reaction proceeds instantaneously and efficiently as long as the contact between the molecules is sufficient. With such a raw material, the reaction proceeds even if the clearance between the outer periphery of the stop ring and the barrel is 500 μm to 1000 μm and there is no catalyst.
On the other hand, many organic synthesis reactions are multistage, and the activation energy of the initial reaction is often relatively high. In order to make these react effectively, it is effective to set the reaction temperature so high that it is not thermally decomposed, and to apply shear force due to stop ring rotation to the reaction field to increase the contact frequency between the reaction molecules. is there. Therefore, it is necessary to determine the clearance between the outer periphery of the stop ring and the barrel.

The stop ring 7 is formed in a double concentric shape (FIG. 4A), the large diameter side of one stop ring 7 is engaged with the small diameter side of the other stop ring 7, and the two stop rings 7 are 2 Each of the screws 3 and 3 is fitted and rotated with the rotation of the screw.
In the case of a non-catalytic reaction, the reaction proceeds even with the stop ring 7 alone.
In the case of a catalytic reaction, a microreactor section 4 can be formed by inserting a ring-like substance 7a having a catalytic action into the small diameter side of the stop ring 7 (FIG. 4B).
Further, a substance 7a having a catalytic action can be formed on a part of the outermost layer by welding or the like (FIG. 4C). In this case, the chemical reaction by the catalytic action can be generated not only in the microreactor unit 4 but also before and after the microreactor unit 4.

  The temperature control mechanism of the microreactor unit 4 includes an electric heater provided outside the barrel, a heating device using high-temperature steam, a heating medium, electric heating, and the like, and a cooling device using water cooling, air cooling, chiller cooling, liquid nitrogen, or the like. For example, a heating device by energization heating is a method of heating by utilizing the Joule heat by energizing the reaction object itself, and is adopted in food chemistry and the like because it is easier to control the product temperature. It is a heating method.

In order to sufficiently advance the chemical reaction in the microreactor unit 4, uniform kneading is performed inside the biaxial extruder before the reaction, and a stable conveying force is required. Therefore, the present invention has a structure in which the degree of kneading is high and a stable conveying force can be obtained.
For example, as a screw structure having a high degree of kneading, it is preferable to use a thick kneading disk having a reverse function.
The kneading disk 6 may be a kneading disk that kneads and shears the raw material in the barrel 2 by combining a plurality of disk pieces of the same or different thickness, a forward disk that moves forward, or a reverse disk that moves backward. . That is, when preparing a plurality of disk pieces having convex portions 6a and concave portions 6b with respect to the circumferential surface and fitting and connecting them on the screw shaft core 3a, the screws are connected in a plan view 1 A kneading / shearing function kneading disk can be obtained by arranging the disk pieces in order such that the locus of every other convex part 6a or concave part 6b is parallel to the axial center (FIG. 2). Further, by arranging the disk pieces in order so that the locus of the convex part 6a or the concave part 6b to be connected has a predetermined angle with respect to the axis 3a, a forward disk or a reverse disk can be obtained ( Figure 2). Even a kneading disk can be made a forward disk or a reverse disk by providing a taper on the circumferential surface of the disk piece.
In the present invention, it is preferable to combine a kneading disk with a reverse type in order to perform kneading effectively.

In order to obtain a stable conveying force, the clearance between the fully meshed screw tip immediately before the reaction region and the barrel is preferably 500 μm or less, more preferably 300 μm or less.
If the raw material to be reacted is a powder raw material, it can be sufficiently conveyed even if the clearance is 500 μm or more. Moreover, although it changes with viscosities, it is preferable that the clearance between a barrel and a screw is 100 μm or less and the clearance between a screw and a screw is 200 μm or less.
The clearance between the barrel and screw also depends on the inner diameter of the barrel, and the smaller the inner diameter, the smaller the clearance must be. For example, when the inner diameter of the barrel is 60 mm or less, the clearance is preferably 100 μm or less.

  The product obtained by causing the reaction raw material to undergo a chemical reaction in the microreactor section 4 needs to prevent heat generation due to shearing after the reaction and to prevent a heterogeneous reaction caused by adhering to the barrel surface. For this reason, it is preferable to use a kneading disk on the downstream side of the microreactor section 4. The raw material filled in the kneading disk can be effectively exchanged heat by cooling from the barrel and the shaft (axial core). A kneading disc having a small top surface and a top surface and barrel clearance of 300 μm or less can be used. In addition, a two-kneading disk body may be used, but in this case, it is preferable that one top surface has a larger clearance than the other top surface. Specifically, it is preferable that the knee-ink disc has an apex angle with respect to the top surface of the knee-ink disc from 0 ° to 5 ° and a clearance between the top surface and the barrel is 0.3 mm or less.

  The extruder type continuous reaction apparatus of the present invention is preferably a multiaxial extruder having a plurality of screws, and more preferably a biaxial extruder having two screws. In the case of a biaxial extruder, it is preferable that the screw has a double-supported structure in which the rotating shaft of the screw shaft is supported at the exit tip. By adopting such a dual-support structure, the chemical reaction can be sufficiently advanced in the microreactor section 4. The screw L / D is preferably 24 or more.

An example of a chemical reaction using the extruder type continuous reaction apparatus of the present invention will be described.
As a form of the raw material to be reacted, it is a raw material that can be bitten into a screw, mixed and conveyed, and any raw material having a melting temperature of about 400 ° C. or less can be used. For example, powder, liquid, or a mixture thereof can be used as a raw material form. Further, the target of the chemical reaction is not limited to the elementary reaction or the organic reaction, and can be applied to various chemical reactions.
The raw material supply method may be any method as long as it can be quantitatively supplied into the reactor, and examples thereof include a constant-weight powder feeder and a method of press-fitting a liquid.
The raw material to be supplied is supplied at a reaction theoretical molar ratio and is not premixed before being supplied to the extruder type continuous reaction apparatus. This is because it is more effective for the chemical reaction to proceed in the microreactor part of the extruder type continuous reaction apparatus.

  The supplied raw materials are mixed by a kneading disk body, conveyed by a screw, and reacted in a microreactor section to obtain a target product. Immediately after the reaction, the product is cooled by a kneading disk disposed on the downstream side of the microreactor section, and the product is discharged.

  Since the extruder type continuous reaction apparatus of the present invention can be used for chemical reactions of various raw materials such as solid-solid and solid-liquid, it can be applied to various chemical synthesis reactions such as organic synthesis in addition to inorganic synthesis.

It is sectional drawing of a biaxial extruder type | mold continuous reaction apparatus. It is a perspective view of a screw. It is screw shaft diameter direction sectional drawing. It is BB sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Continuous reaction apparatus 2 Barrel 3 Screw 4 Microreactor part 5 Screw body 6 Disc body 7 Stop ring

Claims (6)

An extruder type continuous reaction apparatus provided with a barrel, a plurality of screws installed in the barrel, and a microreactor unit for chemically reacting raw materials conveyed by the plurality of screws in the barrel,
The extruder type continuous reaction apparatus, wherein the microreactor part is a gap part formed by an outer peripheral surface of a stop ring provided on the downstream side of the screw and an inner peripheral surface of the barrel.   The extruder type continuous reaction apparatus according to claim 1, wherein the stop ring has a catalytic function.   The extruder type continuous reaction apparatus according to claim 1 or 2, wherein a clearance between the outer peripheral surface of the stop ring and the inner peripheral surface of the barrel is 0.3 mm or less.   The extruder type continuous reaction apparatus according to any one of claims 1 to 3, wherein a kneading disk is disposed upstream of the microreactor section.   A kneeding disk is disposed downstream of the microreactor unit, and the kneeding disk has an apex angle of 0 ° or more and within 5 ° from the center with respect to the top surface of the kneeding disk, and the clearance between the top surface and the barrel is The extruder type continuous reaction apparatus according to any one of claims 1 to 4, wherein the extruder type continuous reaction apparatus is 0.3 mm or less.   6. The extruder according to claim 1, wherein the extruder is a biaxial extruder, and the screw has a double-supported structure that supports a rotating shaft of the screw shaft at a downstream end portion. The extruder type continuous reaction apparatus according to item.

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