JPH0314052B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention provides a method for removing volatile substances such as alcohol and water during the progress of polycondensation, for example, when monomers are polycondensed to produce a high molecular weight polymer. This invention relates to a continuous reaction device for viscous substances.

[Background of the invention]

Generally, when a substance is viscous and the process involves evaporation, such as removal of a volatile substance during the reaction, the process is performed under reduced pressure. The efficiency of evaporation increases in proportion to the degree of pressure reduction, but if the atmospheric pressure is suddenly reduced,
A part of the viscous substance is discharged from the system together with the volatile substance removed by evaporation. In addition, as the evaporation is accelerated, the liquid viscosity increases and the physical properties of the viscous substance change. , volatile substances were removed by sequentially lowering the pressure in each reactor. Here, to explain a conventional polyester continuous polymerization reaction apparatus using an example, when polyester low-polymerizability is polycondensed at high temperature and reduced pressure, the reaction apparatus is designed according to the necessity of gradual reduction of the degree of vacuum and the physical properties of the viscous material. Because of the necessity of selecting a reaction mixture, a three-vessel reactor as shown in FIG. 1 is generally used. That is, in the early stage of polymerization, a rigid reactor 2 is used, and in the middle stage of polymerization, as the viscosity of the viscous substance in the reactor increases and the required evaporation surface area increases, a horizontal uniaxial multi-disk blade reactor 3 is used. is used. However, this uniaxial multi-disk blade reactor 3
The processing viscosity range of viscous substances is several hundred poise at most, and since the viscosity of the liquid is not very high, short passes may occur due to horizontal liquid level differences in the device, and generally multiple partition plates are used. The structure is designed to prevent this.

However, since dead spaces are likely to occur in the vicinity of the partition plates where they are attached, it is desirable to use stirring blades as much as possible to provide a partitioning effect and to reduce the number of partition plates.

Next, in the final polymerization stage, the viscosity of the liquid increases rapidly to about several thousand poise, so a horizontal twin-shaft reactor 4 with good stirring is used. At this final polymerization stage, dead spaces tend to occur due to the high viscosity of the liquid, and countermeasures are required. For this reason,
As shown in Japanese Patent Publication No. 50-21514, a stirring blade has been proposed that can uniformly stir the entire inside of the tank and has a partitioning effect by reducing the number of partition plates that tend to create dead spaces.

In this way, according to the conventional method, the number of components of the reactor is large, resulting in (1) complication of the processing process, (2) increase in the number of operations and maintenance points and complication of work, and (3)
There were disadvantages such as an increase in device production costs and (4) an increase in device installation space.

[Purpose of the invention]

An object of the present invention is to provide a reactor capable of performing intermediate polymerization and final polymerization in one reactor.

[Summary of the invention]

The present invention completely partitions off the gas phase in a conventional horizontal twin-shaft reactor for final polymerization, and provides a plurality of partition plates each having processing liquid passages below the liquid level. By forming chambers and adjusting the operating pressure for each chamber, medium-term polymerization is carried out in the front chamber, and final polymerization is carried out in the rear chamber, allowing both medium-term polymerization and treatment to be carried out in one reactor. The final polymerization treatment is performed.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 2 to 6. Reference numeral 5 denotes a cylindrical reactor main body installed substantially horizontally, and 9 completely partitions off the gas phase within the cylindrical main body 6 in an airtight manner, and includes a processing liquid passage 9a below the liquid level. It is a partition plate. The partition plate 9 partitions the inside of the cylindrical main body 6 in the longitudinal direction to form a front chamber 5a and a rear chamber 5b. 7
9a is a heating jacket provided on the outer periphery of the main body 6;
8 is a processing liquid passage provided at the bottom of the partition plate 9;
Reference characters a and 8b are rotating shafts that penetrate through the partition plate 9 and are provided in parallel within the main body 6. Rotating shaft 8 in the front chamber 5a
Attached to a and 8b are stirring blades 10a and 10b consisting of a plate-shaped support plate 12 with a large surface area fixed symmetrically in the direction perpendicular to the axis, and a scraper 13 fixed perpendicularly to the tip of the support plate 12. On the other hand, an annular support plate 14 with a small surface area is fixed symmetrically to the rotating shafts 8a and 8b in the rear chamber 5b in a direction perpendicular to the shaft.
and stirring blades 11a and 11b each consisting of a scraping plate 15 fixed perpendicularly to the tips thereof are attached. Here, stirring blades 10a, 10b and 11
A, 11b are installed in plural numbers facing each other with a phase angle of 90 degrees, and the rotating shafts 8a,
8b is the stirring blade 10a, 10b and 11a, 11
b is held so that the tip thereof passes close to the rotating shafts 8a, 8b. 16 is the main body 6 of the front chamber 5a
A processing liquid inlet nozzle provided at one end, 17 a processing liquid outlet nozzle provided at the other end of the main body 6 of the rear chamber 5b, and 18 and 19 provided at the upper part of the front chamber 5a and rear chamber 5b of the main body 6, respectively. This is an exhaust nozzle.

Initial polymerization is carried out in the vertical reactor 2, and the inlet nozzle 1
6 to the reactor 5 (liquid viscosity 10
Poise) is caused by the rotation of rotating shafts 8a and 8b that rotate in opposite directions from the inside to the outside of the main body 6 as shown by arrows in the front chamber 5a, and by the plate-shaped stirring blades 10a and 10b with a large surface area. The reaction is promoted by evaporating volatile components while receiving stirring and surface renewal action, and the viscosity gradually increases and moves from left to right in FIG.
reach. Then, it passes through the processing liquid passage 9a and is sent to the rear chamber 5b side.

Here, the processing liquid is not filled in the reaction apparatus, and the upper part of the apparatus is a gas phase section. The gas phase portion of the reactor 5 according to the present invention is completely (airtightly) partitioned by a partition plate 9, and has a front chamber 5a and a rear chamber 5.
Exhaust nozzles 18 and 19 provided in each of b
This allows the operating pressure in each chamber 5a, 5b to be adjusted independently. Normally, the operating pressure in the front chamber 5a is 4 to 8 Torr, and in the rear chamber 5b is about 1 to 2 Torr.

The processing liquid (liquid viscosity approximately 300 poise) supplied into the rear chamber 5b is passed through an annular stirring blade 11 with a small surface area.
a and 11b, the reaction is accelerated by evaporating volatile components while undergoing a surface renewal action, the viscosity gradually increases, and the treatment liquid is taken out from the treatment liquid outlet nozzle 17. Further, the volatile components evaporated within each chamber 5a, 5b are exhausted from exhaust nozzles 18, 19.

Here, stirring blades 10a, 10b in the front chamber 5a
is formed by a plate-shaped support plate 12 with a large surface area that is fixed symmetrically in the direction perpendicular to the axis, and a scraping plate 13 fixed to the tip of the support plate 12, so that the low-viscosity processing liquid in the lower part of the main body 6 can be removed. When the processing liquid is effectively stirred and passes through the upper space, the liquid adheres to the large surface area of the support plate 12 and forms a film, increasing the evaporation area of the liquid and increasing the surface area. The large plate-shaped support plate 12 provides a partitioning effect for the liquid to be treated.

This facilitates the removal of volatile components from the low-viscosity liquid, and allows the liquid to be treated to flow in the longitudinal direction of the main body 6 through a piston. Also,
The scraping plates 13 of the stirring blades 10a, 10b have minute gaps with the inner wall of the main body 6, the outer surfaces of the rotating shafts 8a, 8b, and the scraping plates 13 of other stirring blades 10a, 10b fixed adjacently. Since the agitation effect of the processing liquid is fixed, it can be
In other words, no dead space is created.

In the front chamber 5a, the processing liquid is raised from the lower part of the main body 6 by the scraping plate 13, passes through the space above the processing liquid, and then falls, filling the gap between the support plate 12 and the inner wall of the main body 6 with the lower part of the main body 6. The liquid passes through the liquid outlet nozzle 17, and is stirred by the adjacent stirring blades 10a and 10b in the same manner as described above. Thereafter, the reaction is promoted by moving inside the main body 6 while repeating this action.

In this case, the viscosity of the processing liquid in the front chamber 5a is 10~
Stirring blade 1 because the viscosity is low within the range of 300 poise
By making the support plates 12 of 0a and 10b plate-shaped, the processing liquid can be sufficiently stirred and mixed, and back mixing can be prevented during the short pass.

On the other hand, the processing liquid in the rear chamber 5b has a high viscosity, but since the stirring blades 11a and 11b having an annular support plate 14 with a small surface area are used, it is difficult for the liquid to adhere to the blade surface. It is possible to reduce co-rotation and scaling due to adhesion to the blade surface, which tends to occur during stirring.

In addition, in this embodiment, the front chamber 5a is
The lower half of the interior is divided into two parts. As a result, the processing liquid in the front chamber 5a passes over this weir plate 20 and proceeds from the inlet to the outlet, so that back mixing of the low-viscosity processing liquid in the front chamber 5a can be eliminated.

In the above embodiment, one partition plate 9 was provided in the main body 6 of the reaction device 5 to form two chambers, the front chamber 5a and the rear chamber 5b. A partition plate 9 is provided to form a plurality of chambers, and the pressure in each chamber is sequentially lowered from the inlet to the outlet within the main body 6, and the surface area of the stirring blade in each chamber is sequentially reduced from the inlet to the outlet. Polymerization can also be easily carried out under stirring conditions that are optimal for increasing the viscosity of the treatment liquid.

〔Effect of the invention〕

As described above, according to the present invention, medium-term polymerization and final polymerization treatment, which conventionally required two or more tanks, can be performed in one reaction apparatus.
The number of components of the reactor in the treatment system can be reduced, (1) simplifying the treatment process, (2) reducing the number of operation and maintenance points and simplifying the work, (3) reducing device manufacturing costs, (4) Effects such as a reduction in equipment installation space can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a conventional polymerization reaction apparatus, FIG. 2 is a system diagram showing an embodiment of a polymerization reaction apparatus using a horizontal reaction apparatus according to the present invention, and FIG. 3 is a system diagram of a horizontal reaction apparatus according to the present invention. 4 is a longitudinal sectional view, FIG. 5 is a sectional view taken along line A-A in FIG. 4, and FIG. 6 is taken along line B-B in FIG. 4.
FIG. 2... Vertical reactor, 3... Single-axis multi-disk blade reactor, 4... Horizontal twin-shaft reactor, 5 ... Reactor, 5a... Front chamber, 5b... Rear chamber, 6... Cylindrical main body, 7... heating jacket, 8a, 8b...
Rotating shaft, 9... Partition plate, 9a... Processing liquid passage, 1
0a, 10b, 11a, 11b... Stirring blade, 12
... plate-shaped support plate, 13, 15 ... scraping board,
14... Annular support plate, 16... Processing liquid inlet nozzle, 17... Processing liquid outlet nozzle, 18, 19...
Exhaust nozzle, 20...weir plate.

Claims (1)

[Claims] 1. A cylindrical body provided with a processing liquid inlet nozzle at one end and a processing liquid outlet nozzle at the other end is arranged horizontally, and the gas phase within the main body is completely partitioned, and the liquid The main body is divided into multiple chambers in the longitudinal direction by a partition plate with a processing liquid passage below the surface, and an exhaust nozzle is installed at the top of each of the multiple chambers to adjust the operating pressure for each chamber. Two rotating shafts are installed parallel to each other, a stirring blade with a plate-shaped support plate is attached to the rotating shaft that passes through the chamber on the processing liquid inlet side, and an annular support plate is attached to the rotating shaft that passes through the chamber on the processing liquid outlet side. A horizontal reactor characterized by being equipped with a stirring blade. 2. The main body is divided by a partition plate to form a front chamber and a rear chamber, and a plate-shaped support plate is fixed to two rotating shafts in the front chamber symmetrically in a direction perpendicular to the axis, and a plate-shaped support plate is attached to the tip thereof. A stirring blade consisting of a scraping plate fixed at right angles is attached to two rotating shafts in the rear chamber, and an annular support plate fixed symmetrically at right angles to the shaft, and a scraper fixed at right angle to the tip of the annular support plate. Claim 1, wherein stirring blades made of a mounting plate are attached, and the stirring blades attached to the two rotating shafts are arranged facing each other with a phase angle of 90 degrees. horizontal reactor.