JPS63295602A - Stirring column type polymerizer - Google Patents

Abstract

PURPOSE:To make it possible to produce continuously a polymer with high performance, by combining a cylindrical vessel, a rotating shaft, stirring means, and means of partitioning the vessel longitudinally so as to provide specific actions, thereby increasing the mixing effect. CONSTITUTION:Planar wings 9 are moved in the direction indicated by arrows 11 by the rotation of a rotating shaft 5, and a fluid which has been excluded by the movement of the wings 9 is formed into a large current along the inner circumferential section as indicated by arrows 12. Since the flow speed of the circulating current is higher than the moving speed of inclined wings 10a, 10b, and 10c, the circulating current rotates to pass these inclined wings, and therefore the circulating current is forced to be pushed up relatively by inclinations 10 to moved upwardly. On the other hand, since the fluid near the wall of the vessel moves only gently circumferentially as indicated by arrows 13 under the influence of viscosity resistance from the wall, the fluid is forced to be pushed down by the movement of the inclined wings 10 to be moved downwardly. Thus, an ascending current is formed in the inner circumferential section and a descending current is formed in the outer circumferential section, thereby forming a virtically circulating current.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high-performance polymerization reaction apparatus for continuously producing polymers.

More specifically, the present invention relates to a continuous polymerization reaction apparatus that is mainly used for homogeneous phase solution polymerization and bulk polymerization that increase viscosity.

[Conventional technology]

Solution polymerization and bulk polymerization have traditionally been widely used as polymerization methods for producing polymers.

In a solution polymerization method or a bulk polymerization method, when one polymer is dissolved in a monomer or a solvent, a homogeneous liquid phase system is formed, and as the polymerization reaction progresses, it becomes a highly viscous fluid.

Polymerization reactions taking the above forms include bulk polymerization of polymethyl methacrylate, solution and bulk polymerization of acrylonitrile/styrene resin, solution polymerization of acrylonitrile/butadiene/styrene resin, solution polymerization of polybutadiene, and solution polymerization of styrene/butadiene rubber. Polymerization, nylon 60 polycondensation starting from C-caprolactam (especially in the final stage).

Examples include one condensation (especially in the intermediate stage) of nylon films using adipic acid and hexamethylene diamine as raw materials, and solution polymerization of polyvinyl acetate.

The functions generally required for continuous polymerization reactors for high viscosity fluidization are described in detail by Yasuhiro Murakami in his literature ("Fundamentals and Analysis of M Polymerization Reactors, Baifukan, 1976"). If you select from the contents, the following items will be listed.

(1) The residence time distribution in the R direction is sharp.

In other words, it must have piston flow properties. (2) High uniformity of temperature and concentration (mixing performance) in each region in the flow direction.

(3) There should be no poor flow areas (dead spaces) throughout the entire reactor.

(4) The power required for stirring is low.

(5) Large heat transfer area for removing reaction heat and high heat transfer coefficient.

(6) The device has a simple shape and is easy to clean.

Attempts have been made to satisfy these functions as much as possible, and many polymerization reaction apparatuses have been proposed. However, I have not yet obtained anything worth K14.

[Problem that the invention seeks to solve]

To give an example of a connected reactor that has been proposed in the past, the model device disclosed in Japanese Patent Application No. 127489/1970 requires relatively little stirring power, has a small heat transfer area, and has a complicated device shape. It has drawbacks. Furthermore, in the case of the reactor described in JP-A-53-99290, there is a problem in piston flow properties. Furthermore, the reactor described in JP-A-60-202720 has a complicated structure because it has two shafts.

Continuous polymerization reactors proposed in the past have various problems. The present invention has been developed in view of the current situation, and has a narrow residence time distribution, that is, a piston flow property, a large mixing effect in each stirring zone in the flow direction, no flow defects, and a low stirring power requirement. The object of the present invention is to provide a stirred column polymerization reactor with excellent heat conductivity and a simple structure.

[Means for solving problems]

The present invention includes a cylindrical container equipped with a liquid supply port and a liquid discharge port, a rotating shaft coaxially inserted into the container and coaxial with the axis of the container, and a plurality of units assembled on the side surface of the rotating shaft. A stirring means comprising a flat plate blade whose surface is parallel to the axis of the rotating shaft, and an inclined blade combined with the flat plate blade and attached at an angle with respect to the axis of the rotating shaft; The present invention proposes a stirred column type polymerization reaction apparatus characterized by comprising partition means interposed between the stirring means and the stirring means and partitioning the container in the longitudinal direction.

[For production]

In the reactor having such a configuration, the liquid is supplied into the container from the liquid supply port and introduced into the stirring zone partitioned in the longitudinal direction by the partition means. Within this stirring area, flat plate blades and inclined blades, which are stirring means attached to a rotating shaft, rotate.
Due to their interaction.

Circulating flows such as upward flow, downward flow, and horizontal flow are generated, and due to the stirring and mixing action, the liquid is sufficiently stirred and mixed while being sent to the next stirring area, and is discharged from the system through the liquid outlet of the container while undergoing the same action. is discharged.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the stirred column polymerization reactor according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view of a reactor according to one embodiment of the present invention.

In FIGS. 1 and 2, liquid supply port 1. A rotating shaft 5 is inserted into a container 4 having a liquid outlet 2 and a jacket 3, and the rotating shaft 5 is rotatably sealed with a shaft sealing part 6. The inside of the container 4 is partitioned by multistage baffle plates 7, which serve as partition means, thereby creating a piston flow property in the flow direction.

As the baffle plate 7, a perforated plate with a constant porosity is used.

In each stirring chamber 8 divided by the baffle plate 7, a stirring means is attached to the rotating shaft 5. This stirring means is made up of a flat plate blade 9 whose surface is parallel to the axis I of the rotating shaft 5, and a pair of the flat plate blade 9. In a direction 90° apart from M10,
Three approximately rectangular plate-shaped plates are installed at positions whose heights are sequentially shifted in the axial direction, and are installed in the same direction and at the same inclination angle with respect to the axis 30 of the rotating shaft 5 as shown in the figure. It is composed of inclined blades 10(a), 10(b), and 10(c).

FIG. 2 shows a cross section taken along the line ■-■ in FIG. 1. Due to the rotation of the rotating shaft 5, the flat blade 9 moves in the direction of the arrow 11, and the fluid displaced by this movement moves in the direction of the arrow 12.
As shown in , there is a large circulating flow in the inner circumference. The flow rate of this circulating flow is the same as that of the inclined tool 10(a).

10 fbl , greater than the movement speed of 10(c) and the slope jt 10 (al.

10 (b), 10 (cl) and rotates, so the fluid in the circulating flow is relatively pushed up by the slope R10 and moves upward. On the other hand, the fluid near the container wall is Due to the influence of viscous resistance, it only moves slowly in the circumferential direction as shown by arrow 13.
As the tilting tool 10 moves, it is pushed down and moves downward. In this way, an upward flow occurs at the inner circumference and a downward flow occurs at the outer circumference, and a vertical circulation flow is formed from this K. Note that if the tilting tool is installed with an inclination in the direction opposite to that shown in the drawing, a downward flow will occur at the inner circumference and an upward flow will occur at the outer circumference.

As described above, within the stirring chamber 8, the horizontal circulation flow and the vertical circulation flow occur simultaneously.

A good mixing condition can be obtained.

In addition, the stirring effect by the flat plate g9 is sufficient even in a part of the corner of the stirring chamber 8, so that there is no flow failure area.

In the case of a normal stirring blade, adhesion of gel-like substances etc. often occurs due to poor flow around the rotating shaft, but in the case of the reactor of this embodiment, the Due to the strong circulating flow, the formation of deposits is prevented.

As described above, the large flat blade 9 has the role of generating a horizontal circulating flow, so there is an appropriate size range. In FIG. 2, the front part of the flat plate blade 9 in the rotational direction is in a positive pressure state as the flat plate blade 9 moves while removing fluid, and the rear part is in a positive pressure state to fill the space created by the movement of the flat plate blade 9. Circulating flow flows in, resulting in a feeding state. Since a pressure difference occurs between the front and rear portions of the flat blade 9, a flow short-circuits the gap between the end of the flat blade 9 and the inner wall 31 of the container. Since the circulation flow decreases and the stirring effect decreases in proportion to the increase in the short circuit flow, it is necessary to suppress the short circuit flow as much as possible. The present inventors have determined from numerous experimental results that in order to effectively generate a circulating flow, K is the area surrounded by the shaft center blade and the outer edge of the flat blade 9. It has been found that it is sufficient to occupy at least ω percent, preferably at least ω percent, of the area surrounded by 31 and baffle plate 7.

Next, the power required for stirring is equivalent to that of a normal large paddle blade.
As a stirring blade for high viscosity fluid, it falls into the low power range. In addition, regarding the heat transfer coefficient of the stamp surface, due to the scraping effect of the large flat plate blade and the fluid exchange effect due to the generation of vertical circulation flow, the heat transfer coefficient is higher than that of a normal stirring wheel for high viscosity 1'lle bodies. can get.

Regarding the simplicity of the structure, it is equivalent to a paddle or anchor leak, and it has a simpler structure than the helical ribbon blade that is often used for stirring high sugar e6N bodies or the stirring blade proposed in the conventional patent application mentioned above. It is.

As described above, the reaction apparatus of the above embodiments is as follows.

It has all the functions required of the continuous polymerization reactor mentioned above.

In the above embodiment, a perforated plate was used as the perforated plate, but a plate having any shape and structure, such as a concentric ring, can be used.

The third factor is a longitudinal cross-sectional view of a reactor according to another embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along line 1V-IV in FIG. 3.

In this embodiment, two flat blades 9(a) and 9(b) whose surfaces are parallel to the core blade of the rotating shaft 5 are the blades of the rotating shaft 5.
K, installed with 180° #l on the horizontal plane.

In addition, two inclined devices 10(a) each on the upper and lower sides,
10(b), 10(c), and 10(d) are flat plates g9(a) on the side surface of the rotating shaft 5.

9(b) and 90 degrees apart horizontally, and as shown in the figure, they are installed in the same direction and at the same angle of inclination with respect to the central blade of the rotating shaft 5.

Thus, in the reactor according to the present invention, there is no limit to the number of plates and tilters. Further, a partition means is provided between each stirring chamber 80, and the partition means is a heat exchange section composed of a tube plate, a shell 21, and a tube n, and a high viscosity liquid passing through the tube n. can be heated or cooled by heat medium oil or the like passed through the shell 21 outside the tube n at a distance ωc. Cheap-n functions as a baffle plate as well as heat exchange.

Figure 5 shows a reactor according to yet another embodiment of the present invention! FIG. 6 is a cross-sectional view taken along line VC in FIG. 5.

In this embodiment, a stirring means is shown in which a single flat plate R9 and a spiral inclined blade 10 are combined.

This shows that the reactor according to the present invention is not limited to flat plate-like inclined blades. In addition, a coiled chape n is inserted into the partition means between each stirring chamber 80, and by flowing heat medium oil etc. into the chape, the high viscosity liquid passing therethrough is heated or cooled. , has the function of a baffle board.

Next, experimental results regarding the open time distribution during fWI distillation for the polymerization reaction apparatus of the present invention and the conventional polymerization reaction apparatus will be explained.

In this experiment, a flow test device was used in which the interior of a long cylindrical container made of transparent acrylic resin with an inner diameter of 200 mm was divided into eight stirring sections and seven heating sections. In this experiment, the stirring blades attached to this test device were changed in various ways.

The height of the stirring section is 100 m, and the thermal section is equipped with four acrylic resin chains with an inner diameter of n.

The height is 100fl. These combinations are
The device shown in FIG. 3 is almost similar.

200 poise starch syrup was used as the specimen, and was supplied from the bottom of the container using a gear pump. While the starch syrup was being continuously supplied, the starch syrup colored with red ink was injected in pulses, and the flow condition was observed with the naked eye, and changes in outlet concentration over time were measured.

The residence time distribution was determined.

Table 1 shows the types of stirring blades used and the observation results of the flow state at that time. In Table 1, the comparative example is a conventional reactor, and the experimental example is the above-mentioned example. From Table 1, the following is clear.

(In the case of conventional stirring blade types such as large-sized paddle blades and helical ribbon blades, there was a flow failure area.

(2) In Experimental Examples 1 and 2 using the blade type based on the present invention, no flow failure area was observed.

FIG. 7 shows the measurement results of the residence time distribution of starch syrup in the cylindrical container in the comparative example and each experimental example. In FIG. 7, E(φ) on the vertical axis is the residence time distribution function, and The axis φ is dimensionless time.

In the case of Comparative Example 1, the peak height and position were far off from the complete mixing tank array, and it was also found that there was an abnormally large amount of η that remained for a long time, which is not a desirable state.

In the case of Comparative Example 2, the peak height is low, and the equivalent coefficient of the complete mixing tank row model is also a small value, and it moves away from the piston flow. The reason for this is thought to be that since the vertical circulation flow is larger than the appropriate value, some of the fluid tends to flow from the inlet to the outlet.

Experimental Examples 1 to 3 are close to the complete mixing tank row model.

It has a very favorable residence time distribution.

〔Effect of the invention〕 .

The reaction apparatus according to the present invention exhibits the following special and remarkable effects, and the present invention provides an industrially useful stirring tower type polymerization reaction apparatus.

As a result, it has a piston flow property, and the temperature of the reaction mixture can be adjusted separately in each stirring zone according to the progress of the polymerization reaction. Furthermore, by inserting heat exchange tubes into the partition means, it becomes easier to carry out separate temperature adjustments for each stirring zone.

(2) Since the reaction apparatus according to the present invention is equipped with two types of stirring blades, flat plate blades and inclined blades, on the rotating shaft, highly viscous liquid or slurry substances can be quickly stirred under pressure in the stirring zone. It forms circulating flows of upward flow, downward flow, and horizontal flow, exhibiting high mixing performance, and has no flow defects.

(3) In conventional reactors, gel-like substances often adhered due to poor flow around the stirring rotation axis, but in the reactor according to the present invention, gel-like substances etc. adhered due to good mixing performance. No deposits occur.

(4) Since the reactor according to the present invention is equipped with two types of stirring blades, a flat plate and a tilt source, the required stirring power is smaller than that of a device consisting of only flat blades.

(5) The heat transfer coefficient is large and the heat transfer property is excellent due to the scraping effect of the flat blades and the fluid exchange effect due to the generation of vertical circulation flow.

(6) The device structure is simple.

[Brief explanation of drawings]

Claims (1)

[Claims] A cylindrical container equipped with a liquid supply port and a liquid discharge port, a rotating shaft inserted into the container coaxially with the axis of the container, and a plurality of rotating shafts installed on the side of the same rotating shaft. a stirring means comprising a flat plate blade whose axial center and its surface are parallel, and an inclined blade which is paired with the flat plate blade and is attached at an angle with respect to the axial center of the rotating shaft; 1. A stirring tower type polymerization reaction apparatus comprising: partition means interposed between the container and the container to partition the container in the longitudinal direction.