JP2016032781A - Taylor reactor - Google Patents

Abstract

The present invention provides a Taylor reactor capable of obtaining a desired particle size and particle size distribution. A Taylor is provided with an outer cylinder 1 and an inner cylinder 2 that rotates within the outer cylinder 1, and a plurality of Taylor vortices are generated in a gap space 10 formed between the outer cylinder 1 and the inner cylinder 2. It is a reaction apparatus, Comprising: In the clearance space 10, the shielding board 6 which suppresses the flow between the several Taylor vortices T is provided. The shielding plate 6 is an annular rib and is formed so as to protrude inward from the inner wall surface of the outer cylinder 1. The contact area between the Taylor vortices T in contact with the shielding plate 6 can be reduced, the diffusion between the Taylor vortices T can be suppressed, and the proportion of particles flowing out with a short residence time can be reduced. For this reason, since particles grow to a desired diameter in the same Taylor vortex T and then move to the next Taylor vortex T, particles having a desired particle size and particles having a small particle size distribution are finally obtained. [Selection] Figure 1

Description

    The present invention relates to a Taylor reactor.

  In order to produce micrometer-scale fine particles having a feature in the particle size distribution, a “growth method” using a chemical reaction of gas or solution is generally used. This growth method is a two-step process in which nuclei of fine particles are generated in the first stage and nuclei are grown in the second stage to obtain a desired particle diameter. In this “growth method” between solutions, it is important to control the concentration change at a local location where the feed solutions cause a chemical reaction.

  However, in a conventional stirring tank that is often used for growth methods, a) a dead zone is generated in the stirring tank, b) shear is weak, c) dwell time is non-uniform, etc., causing a chemical reaction. There is a drawback that the concentration of the supply liquid is not uniform in the region inside the agitation tank, and therefore fine particles having a desired particle size and particle size distribution may not be obtained.

In order to eliminate such drawbacks, the conventional technique of Patent Document 1 has proposed a method for controlling the growth of particles by using two Taylor reactors.
The above prior art includes two units, a first-stage Taylor reactor for reacting feed solutions to generate nuclei and a second-stage Taylor reactor for crystal growth of particles. The flow state in the first-stage Taylor reactor forms a slightly slanted donut-shaped pseudo channel, and the feed solution runs in a spiral to cause a chemical reaction. As a result, it is described that the concentration change at the generation site of the chemical reaction is controlled, and the fine particles can be manufactured.

  However, in the prior art of Patent Document 1, since two Taylor reactors are used, there is a problem that the installation space becomes large or it is difficult to perform chemical reaction in order between the two Taylor reactors. It was difficult to obtain a desired particle size and particle size distribution.

Furthermore, not only the above conventional example, but generally the Taylor reactor has the following problems.
As shown in FIG. 6, a general Taylor reaction apparatus has a stationary outer cylinder 101 and a rotating inner cylinder 102, and one end of a tank 110 that is a gap space between the outer cylinder 101 and the inner cylinder 102. A supply pipe 103 is attached to the other end, and a discharge port 104 is provided at the other end. The solution is put into the tank 110 and the inner cylinder 102 is rotated, and Taylor vortices are generated in the tank 110 within the range of the rotation speed. As shown in FIG. 7A, the Taylor vortex T is a donut-shaped swirling fluid, and each Taylor vortex T is an independent fluid. Then, the swirl direction around the inner cylinder is opposite to the adjacent Taylor vortex T, and the flow in the cross section of each Taylor vortex T is also opposite to each other as shown in FIG.

  Many such Taylor vortices are generated adjacent to each other in the tank 110, and the solution itself is gradually moved to the next Taylor vortex, and the solution is agitated to gradually grow particles. Particles of the desired particle size are discharged.

However, some particles that do not grow sufficiently move to the adjacent Taylor vortex one after another, and particles that do not reach the desired particle size may be generated.
As a result, there has been a problem that the particle size distribution is wide and uniform particles cannot be obtained.

JP 2011-83768 A

  In view of the above circumstances, an object of the present invention is to provide a Taylor reactor capable of obtaining a desired particle size and particle size distribution.

A Taylor reactor according to a first aspect of the present invention includes an outer cylinder and an inner cylinder that rotates within the outer cylinder, and a plurality of Taylor vortices are generated in a gap space formed between the outer cylinder and the inner cylinder. The Taylor reaction device is a Taylor vortex generation region, and is characterized in that a shielding plate that suppresses a flow between Taylor vortices is provided in the gap space.
The Taylor reactor of the second invention is characterized in that, in the first invention, a plurality of the shielding plates are provided, and an interval between adjacent shielding plates is an integral multiple of the width dimension of the Taylor vortex. To do.
The Taylor reactor according to a third aspect of the invention is characterized in that, in the first or second aspect of the invention, the shielding plate is an annular rib and is formed so as to protrude inward from the inner wall surface of the outer cylinder. And
A Taylor reactor according to a fourth aspect of the present invention is characterized in that, in the first or second aspect, the shielding plate is an annular rib and is formed to protrude outward from the outer peripheral surface of the inner cylinder. And

According to the first invention, the contact area between the Taylor vortices can be reduced by the shielding plate, so that the diffusion of the solution between the Taylor vortices can be suppressed, and the proportion of particles flowing out with a short residence time can be reduced. . For this reason, the particles grow up to a desired diameter in the same Taylor vortex and then move to the next Taylor vortex, so that particles having a desired particle size and particles having a small particle size distribution are finally obtained.
According to the second invention, when the interval between the shielding plates is an integral multiple of the Taylor vortex width dimension, the shielding plates partition between adjacent Taylor vortices, so that the stirring action by the Taylor vortex is not hindered. Particle growth can be performed in the same Taylor vortex.
According to the third invention, since a gap is formed between the shielding plate and the inner cylinder, particle movement is possible through the gap between the inner cylinder while suppressing contact between adjacent Taylor vortices. Continuous stirring with the Taylor vortex can be performed.
According to the fourth invention, since a gap is formed between the shielding plate and the outer cylinder, particle movement is possible through the gap between the outer cylinders while suppressing contact between adjacent Taylor vortices. Continuous stirring by Taylor vortex can be performed.

It is a longitudinal cross-sectional perspective view of the Taylor reaction apparatus A which concerns on 1st Embodiment of this invention. It is a cross-sectional front view of the Taylor reactor A shown in FIG. It is operation | movement explanatory drawing of a shielding board. It is a section front view of Taylor reaction device B concerning a 2nd embodiment of the present invention. 3 is a graph showing an average residence time in a Taylor vortex in Example 1. FIG. It is explanatory drawing of a Taylor reaction apparatus more general than before. It is explanatory drawing of a Taylor vortex, Comprising: (A) is explanatory drawing of donut-like flow, (B) is explanatory drawing of a cross-sectional flow.

Next, an embodiment of the present invention will be described.
First, based on FIG. 1 and FIG. 2, the basic structure of the Taylor reaction apparatus A in this embodiment is demonstrated.
1 is an outer cylinder, and 2 is an inner cylinder. The outer cylinder 1 is constituted by a double cylinder from an outer plate 1a and an inner plate 1b, and the cavity 1c is used for passing a heating medium. The outer cylinder 1 is used in a stationary state.

  The inner cylinder 2 is a solid or hollow shaft, and is inserted into the outer cylinder 1 concentrically. It is connected to a drive source such as a motor and is rotatable. A gap space 10 is formed between the inner wall surface of the outer cylinder 1 and the outer surface of the inner cylinder 2, and the gap space 10 extends in the cylinder axis direction. That is, the doughnut-shaped gap space 10 is elongated. The gap space 10 is a Taylor vortex generation region and functions as a stirring tank.

A supply port 3 is provided at one end in the longitudinal direction of the outer cylinder 1 (right end in the drawing). As illustrated, it may be formed on the flange 5 or on the outer cylinder 1. The supply port 3 is an introduction port for supplying the pre-reaction solution to the gap space 10 from the outside.
A discharge port 4 is provided at the other end portion in the longitudinal direction of the outer cylinder 1 (left end portion in the drawing). The post-reaction solution in the gap space 10 is discharged from the discharge port 4.

  In the Taylor reactor A of the present embodiment, the Taylor vortex T can be generated in the solution filled in the gap space 10 by rotating the inner cylinder 2 at an appropriate rotational speed.

  As described above with reference to FIG. 7, the Taylor vortex T is a donut-shaped fluid that is generated in the gap space 10 and flows in the circumferential direction around the inner cylinder 2, and the direction of the circumferential flow is adjacent. The direction between the Taylor vortices T is opposite. Moreover, although it flows in the shape of a vortex within the cross section of each Taylor vortex T, the direction is also opposite between the adjacent Taylor vortices T.

Next, features of the Taylor reactor according to the present invention will be described.
In the present invention, the shielding plate 6 that suppresses the flow between the Taylor vortices T is provided in the gap space 10. In the first embodiment of FIGS. 1 and 2, the shielding plate 6 is an annular rib and is formed so as to protrude inward from the inner wall surface of the outer cylinder 1 (the inner plate 1b).

One or a plurality of shielding plates 6 are provided, and the installation area is between the vicinity of the supply port 3 and the vicinity of the discharge port 4. Moreover, the shielding board 6 may be provided over the whole installation area | region, and may be provided partially.
In the case where a plurality of shielding plates 6 are provided, the distance d between the adjacent shielding plates 6 and 6 is preferably an even multiple of the width dimension of the Taylor vortex T. In other words, the distance d is preferably twice or four times the Taylor vortex T.
When the shielding plate 6 is arranged at such a distance d, the shielding plate 6 can be positioned between adjacent Taylor vortices T and T without hindering the flow of the generated Taylor vortex T, which is effective. This is because the contact between Taylor vortices T and T adjacent to each other can be suppressed.

  As shown in FIG. 3, since the shielding plate 6 is inserted between adjacent Taylor vortices T, T, the thinner the thickness 6w of the shielding plate 6, the better. That is, if the thickness is thick, the width of the Taylor vortex T may be reduced, thereby inhibiting natural flow. However, if the shielding plate 6 is thin, the flow of the Taylor vortex T is not inhibited.

Further, it is desirable that a slight gap 6o is provided between the rib tip as the shielding plate 6 and the outer peripheral surface of the inner cylinder 2. The gap dimension is a desirable value of about 1 mm in an apparatus in which the outer diameter of the inner cylinder 2 is 80 to 90 mm and the inner diameter of the outer cylinder 1 is 90 to 100 mm.
With such a numerical gap 6o, a small amount of fluid adjoins through the gap 6o while the majority of the fluid constituting the Taylor vortex T suppresses contact between the adjacent Taylor vortices T by the shielding plate 6. Since it flows into the Taylor vortex, it becomes possible for the solution to sequentially move through a plurality of stages of the Taylor vortex T from the supply port 3 to the discharge port 4. This movement allows the particles to grow sequentially.

Below, the usage method of the Taylor reactor which concerns on 1st Embodiment is demonstrated.
While the outer cylinder 1 is stationary, the inner cylinder 2 is rotated by a motor or the like. The solution before the reaction is caused to flow from the supply port 3, and the product after the chemical reaction is discharged from the discharge port 4.

In the meantime, in the region where the shielding plate 6 is provided, as shown in FIG. 3, the Taylor vortex T flows in the space surrounded by the two shielding plates 6 and hardly contacts the adjacent Taylor vortex T. For this reason, it is possible to suppress diffusion between Taylor vortices and to reduce the proportion of particles that flow out with a short residence time.
However, since some solution moves from the gap 6o to the adjacent Taylor vortex T, the particles grow to the desired diameter in the same Taylor vortex and then move to the next Taylor vortex. And particles having a small particle size distribution are obtained.

Next, the Taylor reactor B of the second embodiment will be described.
In the Taylor reactor B of the present embodiment, the shielding plate 16 is an annular rib and is formed so as to protrude outward from the outer peripheral surface of the inner cylinder 2. Even in the shielding plate 16 having such a configuration, the function of suppressing the contact between the Taylor vortices T and T is the same. For this reason, since particle | grain movement is possible through the clearance gap between the outer cylinders 1, suppressing the contact between adjacent Taylor vortices T and T, continuous stirring by the multiple Taylor vortex T can be implemented.

  Next, Examples 1 and 2 using the Taylor reactor of FIG. 1 will be described. Example 1 uses a Taylor reactor in which 26 Taylor vortices having a width of 1.5 cm are generated in the gap space 10 and the shielding plate 6 is placed in the middle position of the gap space 10 (5th and 6th from the supply side). In the second embodiment, two shielding plates 6 are used. The installation position is provided at an intermediate position of the gap space 10 (between the fifteenth and sixteenth tailor vortices from the supply side in addition to the first embodiment).

  Using the spreadsheet software Excel made by Microsoft, the flow state inside the Taylor reactor A was modeled, and the residence time distribution of particles in the apparatus provided with the shielding plate 6 was calculated. The space volume of the gap space 10 between the outer cylinder 1 and the inner cylinder 2 is defined as V [m3], and the liquid amount Q [L / min] charged from the supply port 3. Since mixing inside the Taylor vortex T proceeds rapidly, a complete mixing state is set. The mixing between the Taylor vortices T was modeled as a diffusion flow rate Q ′ [L / min] due to the concentration gradient. If the difference in cross-sectional area between the outer cylinder 1 and the inner cylinder 1 (the cross-sectional area of the gap space 10) is S [m2] and the axial cross-sectional area of the shielding plate 6 is S '[m2], the insertion of the shielding plate 6 The diffusion flow rate Q ″ [L / min] becomes Q ″ = (S ′ / S) Q ′.

  FIG. 5 shows the calculation result when S ′ / S = 0.1. When the shielding plate 6 is not inserted (reference in the figure), due to the influence of the diffusion flow rate Q ', the residence time distribution gradually approaches the complete mixing state of one tank, and the initial outflow up to 0.2τ becomes 20%. On the other hand, according to the first embodiment in which one shielding plate 6 that can satisfy S ′ / S = 0.1 is inserted, it is possible to suppress the initial outflow up to about 0.2τ to about 11%. According to Example 2 in which two shielding plates 6 are inserted, initial outflow up to 0.2τ can be suppressed to about 5%.

  The graph of FIG. 5 will be further described. The vertical axis is considered to be the outflow rate at the outlet. If the time t / average residence time τ is evaluated in the range of 0 to 0.2 as the ratio of the initial outflow, since there is a mountain in the standard, the area in this region is large (the outflow tends to be early). However, when the shielding plate 6 is introduced, since the distribution is rising, the area becomes small (it is difficult to flow out in the initial stage). That is, it can be understood that as the shape shifts to the right distribution, the residence time of the particles increases, so that the initial outflow decreases.

1 outer cylinder 2 inner cylinder 3 supply port 4 discharge port
6 Shield plate

Claims (4)

Taylor reaction comprising an outer cylinder and an inner cylinder that rotates in the outer cylinder, and a gap space formed between the outer cylinder and the inner cylinder is a Taylor vortex generation region in which a plurality of Taylor vortices are generated A device,
A Taylor reaction apparatus, wherein a shielding plate that suppresses a flow between Taylor vortices is provided in the gap space. The Taylor reaction apparatus according to claim 1, wherein a plurality of the shielding plates are provided, and an interval between adjacent shielding plates is an integral multiple of the width dimension of the Taylor vortex. 3. The Taylor reaction apparatus according to claim 1, wherein the shielding plate is an annular rib and is formed to protrude inward from an inner wall surface of the outer cylinder. 3. The Taylor reaction apparatus according to claim 1, wherein the shielding plate is an annular rib and is formed to protrude outward from the outer peripheral surface of the inner cylinder.

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