CN117136200A

CN117136200A - Reaction apparatus, method for producing vinyl polymer, control apparatus, and stirring apparatus

Info

Publication number: CN117136200A
Application number: CN202280028137.0A
Authority: CN
Inventors: 井田徹; 滨口保典
Original assignee: Shin Etsu Chemical Co Ltd
Current assignee: Shin Etsu Chemical Co Ltd
Priority date: 2021-06-16
Filing date: 2022-06-15
Publication date: 2023-11-28
Also published as: CN117120159A

Abstract

The reaction apparatus of the present invention comprises a reactor having a straight body, a stirring shaft, and stirring blades, wherein the dimensions of the straight body, the dimensions of the stirring blades, and the number of revolutions of the stirring shaft satisfy a relationship represented by N (b/D) (L/D)/N < 6.0. N represents the number of the plurality of stirring blades, b represents the maximum value [ m ] of the blade width of the plurality of stirring blades, D represents the maximum value [ m ] of the blade diameter of the plurality of stirring blades, L represents the length [ m ] of the extending direction of the straight body, D represents the set value of the rotation number [ rps ] of the stirring shaft when the straight body is cut by a plurality of planes which are substantially perpendicular to the extending direction of the straight body and pass through the respective mounting positions of the plurality of stirring blades, and N represents the maximum value [ m ] of the diameter of the plurality of inscribed circles which are substantially inscribed in the straight body in each section formed by the plurality of planes.

Description

Reaction apparatus, method for producing vinyl polymer, control apparatus, and stirring apparatus

Technical Field

The present invention relates to a reaction apparatus, a method for producing a vinyl polymer, a control apparatus, and a stirring apparatus.

Background

Patent document 1 discloses a polymerization apparatus including a baffle plate through which a refrigerant can flow and a serpentine pipe. Patent document 2 discloses a polymerization apparatus including a baffle plate through which a refrigerant can flow and a coil-shaped cooling pipe. Patent document 3 discloses a resin synthesis apparatus including a baffle plate through which a heat medium can flow, and a stirring unit having spiral belt blades and anchor blades.

[ background art document ]

[ patent literature ]

[ patent document 1] Japanese patent laid-open No. 7-233202

[ patent document 2] Japanese patent laid-open No. 7-233206

Patent document 3 Japanese patent laid-open No. 2013-151621

Disclosure of Invention

Embodiment 1 of the present invention provides a reaction apparatus. The reaction apparatus includes, for example, a reactor having a cylindrical straight body. The reaction apparatus includes, for example, a stirring shaft configured to be rotatable. In the reaction apparatus, a part of the stirring shaft is disposed inside the straight body. The reaction apparatus includes, for example, a plurality of stirring blades attached to different positions in the extending direction of the stirring shaft. In the reaction apparatus, a plurality of stirring blades are each installed at a different position in the extending direction of the stirring shaft.

In any of the above reaction apparatuses, the set value of the size of the straight body, the size of at least one of the plurality of stirring blades, and the rotation number of the stirring shaft satisfies, for example, the relationship shown in the following equation 1.

(number 1)

N(b/d)(L/D)/n≦6.0

In the equation 1, N represents the number of the plurality of stirring blades. b represents the maximum value [ m ] of the blade widths of the plurality of stirring blades. d represents the maximum value [ m ] of the blade diameters of the plurality of stirring blades. L represents the length [ m ] of the straight body in the extending direction. D represents a maximum value [ m ] of diameters of a plurality of inscribed circles inscribed in the straight body in each section formed by the plurality of planes when the straight body is cut by the plurality of planes at the mounting positions of the plurality of stirring blades on the plane substantially perpendicular to the extending direction of the straight body. n represents a set value of the rotation number [ rps ] of the stirring shaft.

In any of the above reaction apparatuses, the set value of the rotation number of the stirring shaft, the size of at least one of the straight body, the plurality of stirring blades, and the size of the stirring blade satisfy the relationship shown in the following equation 2. In expression 2, N, b, d, L, D and n are defined as in expression 1.

(number 2)

0.05≦N(b/d)(L/D)/n≦6.0

The above-described reaction apparatus may include a plurality of cooling pipes disposed inside the straight body portion and through which a coolant flows. At least 2 of the plurality of cooling pipes may be different in distance from the inner wall surface of the straight body. In any of the above reaction apparatuses, the set value of the size of the straight body, the size of at least one of the plurality of stirring blades, and the rotation number of the stirring shaft may satisfy the relationship shown in the following expression 3. In equation 3, N, b, d, L, D and n are defined as in equation 1.

(number 3)

0.15≦N(b/d)(L/D)/n≦5.5

In any of the above reaction apparatuses, the set value of the size of the straight body, the size of at least one of the plurality of stirring blades, and the rotation number of the stirring shaft satisfies the relationship shown in the following equation 4. In equation 4, N, b, d, L, D and n are defined as in equation 1.

(number 4)

0.3≦N(b/d)(L/D)/n≦3.0

In any of the above reaction apparatuses, each of the plurality of cooling pipes may have a meandering portion that repeatedly bends and extends. In any of the reaction apparatuses, the meandering portion may include a plurality of extension portions that extend linearly or extend in a curved manner. The meandering portion may include a plurality of curved portions that connect ends of 2 adjacent ones of the plurality of extending portions. In any of the above reaction apparatuses, the ratio of the maximum value of the distances between the adjacent 2 extension portions to the length of the straight body portion in the extension direction may be 0.5 to 15%.

In any of the above reaction apparatuses, the ratio of the minimum value of the distances between the plurality of cooling pipes and the inner wall surface of the straight body to the inner diameter of the straight body may be 0.5 to 10%. In any of the above reaction apparatuses, the ratio of the maximum value of the distances between the plurality of cooling pipes and the inner wall surface of the straight body to the inner diameter of the straight body may be 1 to 30%.

In any of the above reaction apparatuses, the stirring shaft may be attached to the reactor such that the extending direction of the stirring shaft substantially coincides with the extending direction of the straight body. In any of the above reaction apparatuses, the minimum value of the distance between the mounting positions of the plurality of stirring blades in the stirring shaft and the position corresponding to one end of the straight body in the stirring shaft may be 0.1 to 0.45 times the length L in the extending direction of the straight body.

In any of the reaction apparatuses, one end of the straight body may be an upper end of the straight body. In the reaction apparatus, a mounting position of a stirring blade mounted at the lowermost part among a plurality of stirring blades on a stirring shaft is arranged between a 1 st position and a 2 nd position of the stirring shaft. In any of the above reaction apparatuses, the 1 st position may be located above the 2 nd position in the case where the stirring shaft is mounted on the straight body portion. In any of the above reaction apparatuses, the distance between the 1 st position and the position of the stirring shaft corresponding to the lower end of the straight body may be 0.25 times or less the diameter D of the inscribed circle. In any of the above reaction apparatuses, the distance between the 2 nd position and the position of the stirring shaft corresponding to the lower end of the straight body may be 0.1 times or less the diameter D of the inscribed circle. In any of the above reaction apparatuses, the maximum value of the distance between the (N-1) 3 rd position obtained by equally dividing the (N-1) 3 rd position, which is the mounting position of the 1 st stirring blade, and the (N-2) 3 rd position, which is the mounting position of the 2 nd stirring blade, among the plurality of stirring blades, other than the (N-2) 3 rd stirring blade mounted on the uppermost stirring blade and the (2 nd stirring blade mounted on the lowermost stirring blade, may be 0.5 times or less the ratio (D/N) of the diameter D of the inscribed circle to the number N of the plurality of stirring blades.

In any of the reaction apparatuses, the internal volume of the reactor may be 40 to 300m ³ . In the reaction apparatus, the ratio (L/D) of the length L of the straight body in the extending direction to the diameter D of the inscribed circle may be 1.0 to 3.0. In any of the reaction devices, the plurality of stirring vanes may comprise paddle vanes. In any of the above reaction apparatuses, a control unit for controlling the rotation number of the stirring shaft so that the rotation number of the stirring shaft satisfies the relationship shown in expression 1 may be provided.

In embodiment 2 of the present invention, there is provided a method for producing a vinyl polymer. The production method includes, for example, a step of polymerizing a vinyl monomer to produce a vinyl polymer using any of the reaction apparatuses according to embodiment 1. The manufacturing method may have a step of determining a set value of the rotation number of the stirring shaft, the size of at least one of the plurality of stirring blades, and the size of the straight body.

In embodiment 3 of the present invention, a control device is provided. The control device controls, for example, the rotation number of the stirring shaft. In the control device, the stirring shaft is rotatably disposed inside the reactor, for example. The stirring shaft is provided with a plurality of stirring blades, for example. In the control device, the reactor has a cylindrical straight body, for example. In the control device, a part of the stirring shaft is disposed inside the straight body, for example.

The above-described control device controls the rotation number of the stirring shaft so that the rotation number of the stirring shaft satisfies the relationship shown in the following equation 1, for example.

(number 1)

N(b/d)(L/D)/n≦6.0

In embodiment 4 of the present invention, there is provided a stirring device. The stirring device is provided with any one of the control devices according to embodiment 3. The stirring device is provided with a stirring shaft, for example. The stirring device includes, for example, a driving unit for rotating a stirring shaft. In the stirring device, the control device controls the rotation number of the stirring shaft by controlling the output of the driving part.

In addition, the summary does not list all necessary features of the present invention. In addition, sub-combinations of these feature groups may also become the invention.

Drawings

FIG. 1 is a schematic cross-sectional view of an example of a polymerization apparatus 100.

Fig. 2 schematically shows an example of an internal structure disposed in the reaction vessel 110.

Fig. 3 is a schematic cross-sectional view of an example of the reaction vessel 110.

Fig. 4 is a schematic plan view of an example of the reaction vessel 110.

Fig. 5 schematically shows an example of the internal structure of the shutter 232.

Fig. 6 schematically shows an example of the structure of the serpentine cooling tube 252.

Fig. 7 schematically shows another example of the structure of the serpentine cooling tube 252.

Fig. 8 schematically shows another example of the structure of the serpentine cooling tube 252.

Fig. 9 schematically shows an example of a main part of the polymerization apparatus 900.

Fig. 10 schematically shows an example of a main part of the polymerization apparatus 1000.

Fig. 11 schematically shows an example of a main part of the polymerization apparatus 1100.

Fig. 12 schematically shows an example of a main part of the polymerization apparatus 1200.

Fig. 13 schematically shows an example of a main part of the polymerization apparatus 1300.

Fig. 14 schematically shows an example of a main part of the polymerization apparatus 1400.

Fig. 15 schematically shows an example of a main part of the polymerization apparatus 1500.

Fig. 16 schematically shows an example of a main part of the polymerization apparatus 1600.

Fig. 17 schematically shows an example of a main part of the aggregation system 1700.

Fig. 18 schematically shows an example of the mounting position of the stirring blade on the stirring shaft 122.

Detailed Description

The present invention will be described below by way of embodiments of the invention, which are not limited to the inventions of the claims. In addition, all the combinations of features described in the embodiments are not essential to the technical means of the invention. In the present specification, the numerical range "a to B" means a or more and B or less.

According to this embodiment, an example of a procedure of controlling or determining the number of revolutions of a stirring shaft in a reaction apparatus including a reactor having a cylindrical straight body portion, a stirring shaft, and a plurality of stirring blades will be described. In one embodiment of controlling or determining the order of rotation of the stirring shaft, an explanation will be given of an order specific to a case where a plurality of cooling pipes are arranged in a plurality of layers in the diameter direction of the inscribed circle of the straight body portion inside the reactor. Thus, the configuration of the reaction apparatus according to the first embodiment will be described with reference to fig. 1 to 16. Further, details of the procedure of controlling or determining the rotation number of the stirring shaft will be described with reference to fig. 17. An example of the mounting position of the plurality of stirring blades in the stirring shaft will be described with reference to fig. 18.

(outline of polymerization apparatus 100)

Details of an example of the polymerization apparatus 100 will be described with reference to fig. 1, 2, 3, and 4. The polymerization apparatus 100 is used, for example, for the manufacture of polymers. The polymerization apparatus 100 may be used for suspension polymerization.

More specifically, the polymerization apparatus 100 is used for producing a vinyl polymer. As a method for producing a vinyl polymer, a method having a stage of polymerizing a vinyl monomer to produce a vinyl polymer using the polymerization apparatus 100 is exemplified. The method for producing a vinyl polymer includes, for example, a step of storing a raw material containing a vinyl monomer in a reactor disposed in the polymerization apparatus 100. The method for producing a vinyl polymer includes, for example, a step of starting the polymerization reaction of the vinyl monomer to produce a vinyl polymer.

FIG. 1 is a schematic cross-sectional view of an example of a polymerization apparatus 100. In the present embodiment, the polymerization apparatus 100 includes a reaction vessel 110, a stirrer 120, 1 or more (sometimes simply referred to as 1 or more) baffles 130, 1 or more serpentine cooling pipes 140, 1 or more serpentine cooling pipes 150, a jacket 170, and a reflux condenser 180. In the present embodiment, the stirrer 120 includes a stirring shaft 122, stirring blades 124, and a power mechanism 126. In the present embodiment, the baffle 130 includes a main body 132 and 1 or more holders 134. In the present embodiment, the sleeve 170 has a flow passage 172 for the heat medium. In the present embodiment, the reflux condenser 180 has a flow path 182 for the heat medium.

In the present embodiment, the stirring shaft 122 and the stirring blade 124 are disposed inside the reaction vessel 110. In the present embodiment, 1 or more baffles 130 are disposed inside the reaction vessel 110. In the present embodiment, 1 or more serpentine cooling tubes 140 are each disposed inside the reaction vessel 110. In the present embodiment, 1 or more serpentine cooling pipes 150 are each disposed inside the reaction vessel 110.

In the present embodiment, the power mechanism 126 is disposed outside the reaction vessel 110. In the present embodiment, the sleeve 170 is disposed outside the reaction vessel 110. In the present embodiment, the reflux condenser 180 is disposed outside the reaction vessel 110.

In the present embodiment, the serpentine cooling tube 140 and the serpentine cooling tube 150 are disposed at different distances from the inner surface of the reaction vessel 110. Specifically, serpentine cooling tube 150 is disposed closer to the opposite side than serpentine cooling tube 140Should the location of the sides of the container 110. In this case, the distance P between the serpentine cooling tube 140 and the side surface of the reaction vessel 110 _C2 Greater than the distance P between the serpentine cooling tube 150 and the side of the reaction vessel 110 _C1 。

Distance P between serpentine cooling tube 140 and side surface of reaction vessel 110 _C2 The distance between the center of the cross section of the serpentine cooling tube 140 and the side surface of the reaction vessel 110 may be the minimum value. Distance P between serpentine cooling tube 150 and side surface of reaction vessel 110 _C1 The distance between the center of the cross section of the serpentine cooling tube 150 and the side surface of the reaction vessel 110 may be the minimum value. For example, in the case where serpentine cooling tube 140 or serpentine cooling tube 150 is a circular tube, the cross section of serpentine cooling tube 140 or serpentine cooling tube 150 is circular, and the center of the cross section of serpentine cooling tube 140 or serpentine cooling tube 150 is the center of the circle.

Thus, according to the present embodiment, heat in the reaction vessel 110 can be efficiently removed. For example, in the case where the polymerization apparatus 100 is used for the production of a polymer, the polymerization apparatus 100 can efficiently remove the reaction heat generated in the polymerization reaction.

In particular, in suspension polymerization of a vinyl chloride monomer or a monomer mixture mainly composed of a vinyl chloride compound (both are sometimes referred to as a vinyl chloride monomer), if an internal structure such as a cooling coil or a draft tube is disposed in the reaction vessel 110, the power required for the stirrer 120 increases. The shape, size, and placement of the internal structure may affect the mixing performance of the polymerization apparatus 100. Therefore, some internal structures may cause a portion of slow flow to occur inside the reaction vessel 110. If a portion where the flow is slow is generated inside the reaction vessel 110, the internal temperature of the reaction vessel 110 may become uneven. This may cause the particle size and/or polymerization degree of the produced polymer to become uneven, or the polymer scale may easily adhere to the inner wall of the reaction vessel 110 or the surface of the internal structure. Such fouling can be a cause of fish eyes that deteriorate the quality of the molded article using the polymer.

In addition, under the same conditions of heat removal efficiency, the increase in size of the reaction vessel 110 is in trade-off with the reduction in reaction time. Therefore, in order to enlarge the reaction vessel 110 and shorten the reaction time, it is preferable to increase the heat removal efficiency of the polymerization apparatus 100.

As a method for increasing the heat removal efficiency of the polymerization apparatus 100, it is conceivable to reduce the temperature of the refrigerant. However, if the temperature of the refrigerant is lowered, the manufacturing cost of the polymer increases. As another method of increasing the heat removal efficiency of the polymerization apparatus 100, it is considered to increase the heat removal amount of the jacket 170 or the reflux condenser 180. In particular at 40m ³ In the case of the above large-sized polymerizer, if heat is removed only by the sleeve 170, the amount of heat removal will be insufficient, and thus it is considered that the amount of heat removal of the reflux condenser 180 is greatly increased. However, if the heat removal load of the reflux condenser 180 is increased, the foaming amount of the polymer slurry in the inside of the reaction vessel 110 may be increased. If the foaming amount of the polymer slurry increases, the heat removal capacity of the reflux condenser 180 sometimes decreases, or polymer scale adheres to the inside of the reflux condenser 180.

Further, for example, in the case of increasing the capacity of the polymerizer by using the polymerizer described in patent document 1, if the heat conduction area of the serpentine pipe is insufficient, it may be difficult to shorten the reaction time while maintaining the product quality. On the other hand, in the polymerization apparatus described in patent document 2, the heat conduction area can be increased by a relatively simple structure. However, in the structure of the apparatus, the baffle plate and the coil-shaped cooling pipe cannot be arranged on substantially the same circumference. Therefore, the ratio of the area of the coil-shaped cooling pipe to the device capacity can be set relatively small. In the case of using the polymerization apparatus described in patent document 2 to increase the capacity of the polymerizer, if the distance between the coil-shaped cooling pipes is made small to increase the heat conduction area, there is a possibility that the mixing performance of the polymerization apparatus is lowered. In addition, when fouling or a lumpy reactant is generated on the surface of the coil-shaped cooling pipe due to interference or the like, the operation in the tank becomes complicated, and therefore it is difficult to sufficiently remove the fouling or the like.

In contrast, according to the polymerization apparatus 100 of the present embodiment, the serpentine cooling tube 140 and the serpentine cooling tube 150 are disposed at different distances from the inner surface of the reaction vessel 110. Thus, a relatively simple structure having less influence on the mixing performance of the polymerization apparatus 100 can be used to increase the heat conduction area. Further, according to the polymerization apparatus 100 of the present embodiment, the degree of freedom in the installation positions of the serpentine cooling tube 140 and the serpentine cooling tube 150 is large. For example, at least 1 of the 1 or more serpentine cooling tubes 140 and the 1 or more serpentine cooling tubes 150 and the baffle 130 may be disposed on substantially the same circumference. Thus, the serpentine cooling tube 150 may be made to have less impact on the mixing performance of the polymerization apparatus 100 and may increase the heat transfer area of the overall apparatus.

(outline of each section of the polymerization apparatus 100)

In the present embodiment, the reaction vessel 110 stores the raw materials for the synthesis reaction. When the polymerization apparatus 100 is used for producing a polymer, for example, the polymerization is started after a polymerizable monomer, a polymerization initiator, an aqueous medium, a dispersion aid, and the like are charged into the reaction vessel 110. For example, any surfactant may be used as a dispersing aid.

The reaction vessel 110 has a cylindrical shape, for example. The reaction vessel 110 may have a cylindrical shape or a square cylindrical shape. The reaction vessel 110 is provided such that, for example, the extending direction (z direction in the figure) of the reaction vessel 110 is a vertical direction. The reaction vessel 110 includes, for example, a straight body portion and a mirror portion. In the figure, the entire length of the reaction vessel 110 in the extending direction is denoted by H.

Examples of the shape of the cross section (sometimes referred to as a cross section) of the reaction vessel 110 cut at a plane (xy plane in the drawing) perpendicular to the extending direction of the reaction vessel 110 include a circle, an ellipse, and a polygon. The cross-sectional shape of the reaction vessel 110 may be substantially circular, elliptical, or polygonal.

The content of the reaction vessel 110 is not particularly limited, and the content of the reaction vessel 110 is, for example, 1 to 300m ³ . The lower limit of the inner capacity of the reaction vessel 110 may be 40m ³ Can be 80m ³ Can be 100m ³ Can be 120m ³ Can be 130m ³ Can be 150m ³ Can be 200m ³ May also be 250m ³ . The upper limit of the inner capacity of the reaction vessel 110 may be 300m ³ The above. The upper limit of the inner capacity of the reaction vessel 110 may be 350m ³ May be 400m ³ . The larger the inner capacity of the reaction vessel 110, the more advantageously the cooling capacity of the present embodiment can be improved.

The content of the reaction vessel 110 is defined as the capacity in the case where the reaction vessel 110 stores the liquid up to a predetermined upper limit of the reaction vessel 110. The content of the reaction vessel 110 is, for example, the internal volume of the reaction vessel 110 in the case where an internal structure such as a stirring shaft, a blade, a baffle plate, or a coil is not disposed in the reaction vessel 110.

As described above, the increase in size of the reaction vessel 110 is in trade-off with the reduction in reaction time. If the internal volume of the reaction vessel 110 is 40m ³ As described above, the heat removal efficiency of the polymerization apparatus 100 tends to be insufficient, and it is difficult to shorten the reaction time while enlarging the reaction vessel 110. In particular, the internal volume of the reaction vessel 110 is 80m ³ In the above cases, the effect of the polymerization apparatus 100 according to the present embodiment is more remarkable. Details of the reaction vessel 110 are described below.

In the present embodiment, the stirrer 120 stirs the liquid stored in the reaction vessel 110. In the present embodiment, the stirring shaft 122 holds the stirring blade 124 and rotates the stirring blade 124. In the present embodiment, the stirring blade 124 is attached to the stirring shaft 122, and stirs the liquid stored in the reaction vessel 110.

The shape of the stirring blade 124 is not particularly limited, and examples of the shape of the stirring blade 124 include a wushu blade, a cloth-coded blade, a paddle blade, a pitched paddle blade, a turbine blade, a propeller blade, and a combination of these. As a result, the stirring shaft 122 rotates, and a discharge flow radially outward from the stirring shaft 122 is generated. The number of the stirring blades 124 is not particularly limited, and 2 to 6 blades are exemplified as the number of the stirring blades. The installation position and the number of the stirring blades 124 are not particularly limited, and the stirring blades 124 are preferably provided in a plurality of stages. The number of stages of the stirring blade 124 is 2 to 6.

In the present embodiment, the power mechanism 126 rotates the stirring shaft 122. The power mechanism 126 includes, for example, a power unit (not shown) for generating power and a power transmission unit (not shown) for transmitting the power generated by the power unit to the stirring shaft 122. The power section exemplifies a motor. The power transmission unit exemplifies a speed reducer.

The rotation number of the stirring shaft 122, the shape, the size, the number of the blades, the installation position, the installation number, and the installation interval C of the stirring blades 124 _i The polymerization apparatus 100 is appropriately determined according to its use. The rotation number of the stirring shaft 122, the shape, the size, the number of the blades, the installation position, the installation number, and the installation interval C of the stirring blades 124 _i For example, the content of the reaction vessel 110, the shape of the reaction vessel 110, the internal structure disposed inside the reaction vessel 110, the structure of the heat removal unit, the heat removal capacity, and the composition of the raw materials charged for polymerization are taken into consideration.

For example, in the case where the polymerization apparatus 100 is used for suspension polymerization, the stirring energy applied to the content (in this case, the aqueous suspension mixture) is 80 to 200kgf·m/s·m ³ The number of revolutions of the stirring shaft 122 is determined. Here, the "stirring energy" applied to the content is defined as the net energy required for stirring per unit amount of the content (sometimes referred to as unit volume) obtained by subtracting the energy B of various energy losses such as motor efficiency, conduction loss, and mechanical loss from the energy a of the drive motor load for the stirrer disposed in the power unit 126 during the operation of the polymerization apparatus 100. As the unit amount, a unit mass, a unit volume, and the like are exemplified. For example, when the volume of the content is C, the stirring energy is calculated by the following equation E.

(numerical type E)

(Α－B)/C[kgf·m/s·m ³ ]

The energy to be loaded by the drive motor for the mixer can be measured electrically by a measuring device such as an ammeter. Further, the stirring energy can be easily adjusted by changing the rotation number of the stirring shaft 122.

The rotation number of the stirring shaft 122 is set to, for example, 10 to 1000 rpm. The set value may be preferably used, for example, in the case where the polymerization apparatus 100 is used for suspension polymerization. As a method of determining the rotation number of the stirring shaft 122 so that the stirring energy falls within the above numerical range, (i) a method using a scale-up test, (ii) a method using a relational expression such as an experimental expression or an empirical expression, and the like are exemplified.

In one embodiment, the number of revolutions of the stirring shaft 122 in the polymerization apparatus 100 is determined based on, for example, a polymerization test performed in a test factory in advance. In general, the scale up from the test plant to the polymerization apparatus 100 is performed so that the stirring state of the polymerization apparatus 100 substantially matches the stirring state of the test plant. For example, in the test plant and the polymerization apparatus 100, the shape, size, and arrangement of each internal structure are determined in such a manner that the shape and size of the reaction vessel 110 are similar to the shape, size, and arrangement of the internal structures such as the stirring blade 124, the baffle 130, the serpentine cooling tube 140, the serpentine cooling tube 150, and the like.

Thus, according to one embodiment, the number of revolutions of the stirring shaft 122 in the polymerization apparatus 100 can be determined so that the stirring energy in the polymerization apparatus 100 is substantially the same as the stirring energy in the test plant. As described above, the stirring energy is calculated, for example, in the form of "(a-B)/C". As a method for determining the rotation number of the stirring shaft 122 based on the stirring energy, any known method can be used.

The rotation number of the stirring shaft 122 in the test plant is determined in the following order, for example. For example, the relationship between the number of revolutions of the stirring shaft 122 in the test plant and the quality of the polymer is obtained by a polymerization test using the test plant. This determines the number of revolutions of the stirring shaft 122 to obtain the polymer of the target quality. The quality is not particularly limited, and examples of the quality include particle size.

Specifically, in a polymerization test using a test plant, the polymerization temperature is set according to the reduction viscosity (sometimes referred to as K value) of the target polymer. Here, the polymerization temperature has a correlation with the average polymerization degree of the polymer, and the K value of the polymer is widely used as an index indicating the average polymerization degree of the polymer.

In addition, in the polymerization test using the test plant, the polymerization time was determined according to the heat removal capacity of the test plant. For example, the polymerization time is determined based on (i) the amount of monomer to be charged as a starting material, (ii) the amount of polymerization initiator to be charged, and (iii) the heat removal capacity of the test plant so that the amount of generated heat of reaction does not exceed the heat removal capacity of the test plant.

When the polymerization time is set so that the test plant has a sufficient heat removal capacity, a polymer having a desired average polymerization degree can be produced by setting the polymerization temperature according to a desired value of K. Thus, for example, polymerization tests were performed under a plurality of conditions in which the polymerization temperature and polymerization time were the same and the rotation number of the stirring shaft 122 was different.

Based on a plurality of test results in which the rotation number of the stirring shaft 122 is different, the relationship between the rotation number of the stirring shaft 122 and the quality of the polymer in the test plant is obtained. Thus, if the target value of the quality of the polymer is determined, the rotation number of the stirring shaft 122 for obtaining the target quality of the polymer can be determined.

When the polymerization time is set so that the test plant has a sufficient heat removal capacity, setting the polymerization temperature according to the target value of the K value results in a polymer having a target average polymerization degree. On the other hand, when the heat removal capability of the test plant is insufficient for the set polymerization time, the polymerization temperature increases due to heat generation by the polymerization reaction. As described above, there is a correlation between the polymerization temperature and the average polymerization degree of the polymer produced. Therefore, when the polymerization temperature increases, an error between the K value of the produced polymer and the target value of the K value becomes large. In addition, depending on the degree of increase in polymerization temperature, the reaction may not be controlled.

In this way, the K value of the polymer produced can be used as an index related to the heat removal capacity of the polymerization apparatus 100. For example, in the case of producing a polymer using the polymerization apparatus 100, when a target K value is obtained with respect to a set polymerization time, it can be determined that the polymerization apparatus 100 has a sufficient heat removal capability.

As described above, the scale up from the test plant to the polymerization apparatus 100 is performed so that the stirring state of the polymerization apparatus 100 substantially matches the stirring state of the test plant. For example, when the ratio of the size of each internal structure disposed in the reaction vessel 110 to the inside diameter and/or the height of the straight body of the reaction vessel 110 in the target polymerization apparatus 100 is substantially equal to the ratio of the size of each internal structure in the test plant to the inside diameter and/or the height of the straight body of the reaction vessel in the test plant, the stirring state of the polymerization apparatus 100 with the enlarged scale is substantially equal to the stirring state of the test plant when the stirring energy in the polymerization apparatus 100 is substantially equal to the stirring energy in the test plant.

For example, the size of the baffle plate 130 in the target polymerization apparatus 100 is determined so that the ratio of the length of the baffle plate 130 in the extending direction (vertical direction in the drawing) to the height of the straight body portion of the reaction vessel 110 is substantially the same between the test plant and the target polymerization apparatus 100. The size of the baffle plate 130 in the target polymerization apparatus 100 is determined so that the ratio of the length of the baffle plate 130 in the direction substantially perpendicular to the extending direction (the left-right direction in the drawing) to the diameter (sometimes referred to as the inner diameter) of the inside of the reaction vessel 110 is substantially the same between the test plant and the target polymerization apparatus 100. The number and arrangement of the baffles 130 in the target polymerization apparatus 100 are determined so that the number and arrangement of the baffles 130 are substantially the same between the test plant and the target polymerization apparatus 100. The same applies to other structures (e.g., stirring blade 124, serpentine cooling tube 140, serpentine cooling tube 150, etc.).

Further, as described above, if the target value of the quality of the polymer in the scale-up polymerization apparatus 100 is determined, the rotation number of the stirring shaft 122 in the scale-up polymerization apparatus 100 can be determined based on the relationship between the rotation number of the stirring shaft 122 in the test plant and the quality of the polymer. Specifically, first, the rotation number of the stirring shaft 122 in the test plant is determined based on (i) the target value of the quality of the polymer in the polymerization apparatus 100 and (ii) the relationship between the rotation number of the stirring shaft 122 in the test plant and the quality of the polymer. Next, the number of revolutions of the stirring shaft 122 in the polymerization apparatus 100 was determined so that the stirring energy in the polymerization apparatus 100 was substantially the same as the stirring energy in the test plant.

Thus, the shape, size, number of blades, installation position, installation number, and installation interval C of (i) the stirring blade 124 of the target polymerization apparatus 100 can be considered _i And (ii) the internal volume of the reaction vessel 110, the shape of the reaction vessel 110, and the internal structure disposed inside the reaction vessel 110, etc., without strictly measuring the stirring energy per unit volume [ kgf. M/s. M ] ³ ]In the case of (2), the number of rotations of the stirring shaft 122 of the target polymerization apparatus 100 is determined. The number of revolutions of the stirring shaft 122 in the target polymerization apparatus 100 may be determined based on the simulation result of the polymerization test.

In another embodiment, the rotation number of the stirring shaft 122 in the polymerization apparatus 100 is determined so that the set value of the rotation number of the stirring shaft 122, the size of at least one of the plurality of stirring blades 124, and the size of the straight body portion of the reaction vessel 110 satisfy the relationship shown in the following expression 1.

(number 1)

N(b/d)(L/D)/n≦6.0

In equation 1, N represents the number of the plurality of stirring blades 124. b represents a maximum value [ m ] of the blade widths of the plurality of stirring blades 124. d represents a maximum value [ m ] of the blade diameters of the plurality of stirring blades 124. L represents the length [ m ] of the straight body of the reaction vessel 110 in the extending direction. D represents a maximum value [ m ] of diameters of a plurality of inscribed circles inscribed in the straight body in each section formed by the plurality of planes when the straight body is cut by the plurality of planes at the mounting positions of the plurality of stirring blades 124 with the plane substantially perpendicular to the extending direction of the straight body. In the case where the reaction vessel 110 has a cylindrical straight body, D is the inner diameter [ m ] of the straight body. n represents a set value of the rotation number [ rps ] of the stirring shaft 122.

The blade diameter of the stirring blade 124 may be the rotational diameter of the stirring blade 124. The rotation diameter of the stirring blade 124 may be a diameter of a rotating body obtained by rotating the stirring blade 124 around the stirring shaft 122. The blade diameter of the stirring blade 124 may be the entire length of the stirring blade 124 in a direction substantially perpendicular to the extending direction of the stirring shaft 122 (for example, the left-right direction in fig. 1) when the stirring blade 124 is attached to the stirring shaft 122.

The blade width of the stirring blade 124 may be the height of a rotating body obtained by rotating the stirring blade 124 around the stirring shaft 122. The blade width of the stirring blade 124 may be the entire length of the stirring blade 124 in a direction substantially parallel to the extending direction of the stirring shaft 122 (for example, the up-down direction in fig. 1) when the stirring blade 124 is attached to the stirring shaft 122.

According to the present embodiment, the rotation number of the stirring shaft 122 can be easily determined as compared with the case where the rotation number of the stirring shaft 122 is determined according to a polymerization test in a test factory performed in advance. Even when the rotation number of the stirring shaft 122 is determined based on a polymerization test in a test plant performed in advance, the rotation number of the stirring shaft 122 can be easily determined by taking the relationship of the above-described expression 1 into consideration.

Preferably, the size of the straight portion of the reaction vessel 110, the size of at least one of the plurality of stirring blades 124, and the set value of the rotation number of the stirring shaft 122 are determined so as to satisfy the relationship shown in the following equation 2.

(number 2)

0.05≦N(b/d)(L/D)/n≦6.0

When the polymerization apparatus 100 includes 1 or more serpentine cooling pipes 140 or 1 or more serpentine cooling pipes 150, the size of the straight portion of the reaction vessel 110, the size of at least one of the plurality of stirring blades 124, and the set value of the rotation number of the stirring shaft 122 are preferably determined so as to satisfy the relationship shown in the following equation 3.

(number 3)

0.15≦N(b/d)(L/D)/n≦5.5

When the polymerization apparatus 100 includes 1 or more serpentine cooling pipes 140 and 1 or more serpentine cooling pipes 150, it is preferable that the dimensions of the straight portion of the reaction vessel 110, the dimensions of at least one of the plurality of stirring blades 124, and the set value of the rotation number of the stirring shaft 122 are determined so as to satisfy the relationship shown in the following equation 4.

(number 4)

0.3≦N(b/d)(L/D)/n≦5.5

In one embodiment, the set value of the rotation number of the stirring shaft 122 in the polymerization apparatus 100 is determined according to the size of the straight portion of the reaction vessel 110, the size of at least one of the plurality of stirring blades 124, and the equation 1. In another embodiment, the size of at least one of the straight portion of the reaction vessel 110 and the size of the plurality of stirring blades 124 is determined based on the set value of the rotation number of the stirring shaft 122 in the polymerization apparatus 100 and the equation 1. Details of these embodiments will be described with reference to fig. 17 described below.

In the present embodiment, the baffle 130 improves the mixing performance of the polymerization apparatus 100. For example, the baffle 130 improves the mixing performance in the up-down direction inside the reaction vessel 110. The installation position of the baffle plate 130 is not particularly limited, and for example, the baffle plate 130 is disposed in the vicinity of the inner wall of the reaction vessel 110. The baffle 130 may be supported by the side walls of the reaction vessel 110. In another embodiment, the baffle 130 is supported by the ceiling or floor of the reaction vessel 110 and is disposed in the vicinity of the stirring blade 124. When the polymerization apparatus 100 is used for producing a polymer, the baffle 130 may be disposed so that the upper end of the baffle 130 is not in the liquid phase, or may be disposed so that the upper end of the baffle 130 is not in the liquid phase.

The number of baffles 130 is preferably about 1 to 12, more preferably about 2 to 8, still more preferably about 3 to 6, and still more preferably about 4 to 6. Preferably, an even number of baffles 130 are arranged substantially symmetrically about the axis of extension (sometimes referred to as the central axis) of the reaction vessel 110. This improves the mixing performance of the polymerization apparatus 100, and suppresses the stagnation of the liquid. Thus, the occurrence of scale can be suppressed.

In the present embodiment, the main body 132 of the baffle 130 improves the mixing performance of the polymerization apparatus 100. The shape of the main body 132 is not particularly limited, and the main body 132 has, for example, a plate-like or tubular shape extending substantially parallel to the extending direction of the reaction vessel 110. In the case where the body 132 has a cylindrical shape, the diameter of the body 132 may be 40 to 500mm. The length Bh (sometimes referred to as the height Bh) of the main body 132 in the extending direction (z direction in the drawing) is not particularly limited.

The length Bw (sometimes referred to as width Bw) of the main body 132 in a direction substantially perpendicular to the extending direction (x or y direction in the drawing) is not particularly limited. The ratio of the width Bw of the main body 132 to the inner diameter of the reaction vessel 110 may be 1 to 10%, may be 2.5 to 7.5%, and may be 3 to 7%.

When the main body 132 has a cylindrical shape, the ratio of the total value of the cross-sectional areas of 1 or more main bodies 132 each having a cylindrical shape to the cross-sectional area of the straight body of the reaction vessel 110 may be 0.4 to 3%. If the ratio is less than 0.4%, the function as a baffle may be insufficient, and the mixing in the up-down direction inside the reaction vessel 110 may be insufficient. For example, in the case where the polymerization apparatus 100 is provided with a single baffle 130, the ratio may be less than 0.4%. For example, in suspension polymerization of vinyl chloride monomer, when mixing in the up-down direction inside the reaction vessel 110 is insufficient, the particle size distribution of the produced polymer becomes wide. This may lead to an increase in fish eyes, for example, in the case of shaping the produced polymer into a sheet, and a decrease in quality of the shaped article.

On the other hand, in the case where the ratio exceeds 3%, the power required for the stirrer 120 excessively increases. Further, the fluidity of the liquid between the baffle 130 and the inner wall surface of the reaction vessel 110 may be reduced. This may cause scale to adhere to the reaction vessel 110 or to a structure inside the reaction vessel 110. For example, in the case where the polymerization apparatus 100 is provided with more than 8 baffles 130, the ratio may sometimes be more than 3% depending on the design of the polymerization apparatus 100.

The body 132 of at least 1 baffle 130 may have a flow path for circulating a heat medium. The flow path may be formed inside the main body 132 or may be disposed outside the main body 132. The flow path may be a single-layer pipe or a double-layer pipe structure.

The heat medium may be a well-known refrigerant. Examples of the refrigerant include water, brine, fluorochloroalkane, and other liquefied gases. In the case of using liquefied gas as the refrigerant, the liquefied gas can function as the refrigerant by evaporating in the serpentine cooling tube 140. The linear velocity of the refrigerant can be about 0.1 to 6.0 m/s.

The main body 132 is connected to an inner wall surface of the reaction vessel 110 via a bracket 134, for example. The distance between the main body 132 and the inner wall surface of the polymerization apparatus 100 is preferably 40mm or more. If the distance is less than 40mm, polymer scale may easily adhere between the inner wall surface of the reaction vessel 110 and the baffle 130 in the vicinity of the gas-liquid interface in the reaction vessel 110. Details of the main body 132 are described below.

In the present embodiment, the holder 134 holds the main body 132. For example, one end of the holder 134 is in contact with the inner wall surface of the reaction vessel 110, and the other end of the holder 134 is in contact with the main body 132. As described above, the holder 134 can hold the main body 132 such that the distance between the main body 132 and the inner wall surface of the polymerization apparatus 100 is 40mm or more.

In the present embodiment, serpentine cooling tube 140 has a flow path for circulating a heat medium formed therein. The serpentine cooling tube 140 may be a single layer tube. The serpentine cooling tube 140 is disposed closer to the central axis of the reaction vessel 110 than the serpentine cooling tube 150. The number of serpentine cooling tubes 140 is preferably about 1 to 12, preferably about 2 to 8, more preferably about 3 to 6, and even more preferably about 4 to 6. Preferably, an even number of serpentine cooling tubes 140 are arranged substantially symmetrically about the central axis of the reaction vessel 110.

In the present embodiment, at least a part of the serpentine cooling tube 140 is repeatedly bent and extended. The length Ph of the portion of the serpentine cooling tube 140 that is repeatedly bent and extended in the extending direction may be smaller than the length Bh of the main body 132 of the baffle 130 in the extending direction (z direction in the drawing), and may be substantially the same as the length Bh or larger than the length Bh. Thereby, the heat conduction area per unit installation area becomes large.

In the example shown in fig. 1, the serpentine cooling tube 140 is repeatedly bent and extends substantially parallel to the extending direction of the reaction vessel 110. In the example shown in fig. 1, the serpentine cooling tube 140 is repeatedly bent and extended as a whole. The ratio of the length Ph of the portion of the serpentine cooling tube 140 that is repeatedly bent and extended in the extending direction to the total length Pt (not shown) of the serpentine cooling tube 140 in the extending direction may be 0.25 or more, may be 0.5 or more, may be 0.75 or more, may be 0.8 or more, or may be 0.9 or more.

When the polymerization apparatus 100 is used for producing a polymer, the serpentine cooling tube 140 may be disposed such that the upper end of the serpentine cooling tube 140 is not in the liquid phase. This is because if the upper portion of the serpentine cooling tube 140 is exposed to the gas phase, the heat conduction efficiency is lowered or polymer scale is likely to adhere to the serpentine cooling tube 140. At the end of the polymerization the gas-liquid interface decreases due to liquid shrinkage. Therefore, it is preferable that the serpentine cooling tube 140 is disposed at a position having a sufficient distance from the gas-liquid interface at the upper end of the serpentine cooling tube 140 even at the end of polymerization. Details of serpentine cooling tube 140 are described below.

In the present embodiment, the serpentine cooling tube 150 forms a flow path for circulating a heat medium therein. The serpentine cooling tube 150 may be a single layer tube. The serpentine cooling tube 150 is disposed closer to the side wall of the reaction vessel 110 than the serpentine cooling tube 140. The number of serpentine cooling tubes 150 is preferably about 1 to 12, more preferably about 2 to 8, still more preferably about 3 to 6, and still more preferably about 4 to 6. The number of serpentine cooling tubes 150 may be the same as the number of serpentine cooling tubes 140 or may be different from the number of serpentine cooling tubes 140. Preferably, an even number of serpentine cooling tubes 150 are arranged substantially symmetrically about the central axis of the reaction vessel 110.

In the present embodiment, at least a part of the serpentine cooling tube 150 is repeatedly bent and extended. The length Ph of the portion of the serpentine cooling tube 150 that is repeatedly bent and extended in the extending direction may be smaller than the length Bh of the main body 132 of the baffle 130 in the extending direction (z direction in the drawing), and may be substantially the same as the length Bh or larger than the length Bh. Thereby, the heat conduction area per unit installation area becomes large.

In the example shown in fig. 1, the serpentine cooling tube 150 is repeatedly bent and extends substantially parallel to the extending direction of the reaction vessel 110. In the example shown in fig. 1, the serpentine cooling tube 150 is repeatedly bent and extended as a whole. The ratio of the length Ph of the portion of the serpentine cooling tube 150 that is repeatedly bent and extended in the extending direction to the total length Pt (not shown) of the serpentine cooling tube 150 in the extending direction may be 0.25 or more, may be 0.5 or more, may be 0.75 or more, may be 0.8 or more, or may be 0.9 or more.

When the polymerization apparatus 100 is used for producing a polymer, the serpentine cooling tube 150 may be disposed such that the upper end of the serpentine cooling tube 150 is not in the liquid phase. This is because if the upper portion of the serpentine cooling tube 150 is exposed to the gas phase, the heat conduction efficiency is lowered or polymer scale is likely to adhere to the serpentine cooling tube 150. At the end of the polymerization the gas-liquid interface decreases due to liquid shrinkage. Therefore, it is preferable that the serpentine cooling tube 150 is disposed at a position having a sufficient distance from the gas-liquid interface at the upper end of the serpentine cooling tube 150 even at the end of polymerization.

In one embodiment, the flow direction of the coolant in the serpentine cooling tube 150 is set so that the coolant flows from below the reaction vessel 110 to above the reaction vessel 110. In another embodiment, the flow direction of the refrigerant in the serpentine cooling tube 150 is set so that the refrigerant flows from above the reaction vessel 110 to below the reaction vessel 110.

For example, the liquid returned from reflux condenser 180 has a lower temperature and a higher density than the liquid in reaction vessel 110. Therefore, in the vicinity of the inlet of the liquid returned from the reflux condenser 180, the liquid tends to flow downward from above in the reaction vessel 110. Thus, for example, the serpentine cooling tube 150 disposed in the vicinity of the inlet of the liquid returned from the reflux condenser 180 may be configured such that the refrigerant flows from below the reaction vessel 110 to above the reaction vessel 110. Details of serpentine cooling tube 150 are described below.

In the present embodiment, the jacket 170 heats or cools the reaction vessel 110 from outside the reaction vessel 110. As described above, the sleeve 170 has the flow path 172 configured to be capable of flowing a heat medium. The sleeve 170 controls at least one of the temperature and the flow rate of the heat medium flowing through the flow path 172 to adjust the heating amount and the heat removal amount of the reaction vessel 110.

The heat medium may be a well-known refrigerant. Examples of the refrigerant include water, brine, fluorochloroalkane, and various liquefied gases. As the refrigerant, a liquid refrigerant is preferably used. In the case of using liquefied gas as the refrigerant, the liquefied gas can function as the refrigerant by evaporating in the serpentine cooling tube 140. The linear velocity of the refrigerant can be about 0.1 to 6.0 m/s.

In the present embodiment, the reflux condenser 180 is used for heat removal from the reaction vessel 110. For example, vapor from the reaction vessel 110 is supplied to a reflux condenser 180. Reflux condenser 180 cools the vapor to liquefy it. Reflux condenser 180 returns the liquid produced by the cooling back to reaction vessel 110. As described above, the reflux condenser 180 has the flow path 182 configured to be capable of flowing the heat medium. The reflux condenser 180 cools the vapor from the reaction vessel 110 by heat exchange between the heat medium flowing through the flow path 182 and the vapor of the reaction vessel 110. The heat removal amount of the reaction vessel 110 can be adjusted by controlling at least one of the temperature and the flow rate of the heat medium flowing through the flow path 182.

(relation of Heat removal units)

As described above, in the present embodiment, the reaction vessel 110 includes the heat removal unit, the baffle 130, the serpentine cooling tube 140, the serpentine cooling tube 150, the jacket 170, and the reflux condenser 180. The ratio of the amount of heat removed by each heat removing device to the total amount of heat generated is not particularly limited. The ratio is determined in consideration of, for example, the quality of the polymer produced, the manufacturing cost, and the like. For example, the ratio of the heat removal amount of the shutter 130 to the total heat generation amount is preferably 10 to 30%. The ratio of the total amount of heat removal of serpentine cooling tube 140 and serpentine cooling tube 150 to the total amount of heat generation is preferably 10 to 50%. The ratio of the heat removal amount of the sleeve 170 to the total heat generation amount is preferably 20 to 40%. The ratio of the heat removal amount of the reflux condenser 180 to the total heat generation amount is preferably 10 to 50%.

It is preferable that the ratio of the total surface area of the serpentine cooling tube 140 and the serpentine cooling tube 150 to the inner capacity of the reaction vessel 110 is 0.1 to 0.9[ m ] ² /m ³ ]Is designed in the manner of (a). The ratio is more preferably 0.5 to 0.7[ m ] ² /m ³ ]. Thus, the ratio of the total amount of heat removal of serpentine cooling tube 140 and serpentine cooling tube 150 to the total amount of heat generation can be made to be 10 to 50%.

(materials of the respective portions of the polymerization apparatus 100)

The material of each part of the polymerization apparatus 100 is appropriately determined in consideration of mechanical strength, corrosion resistance, thermal conductivity, and the like. For example, stainless steel such as high-chromium high-purity ferrite-based stainless steel, 2-phase stainless steel, or austenitic stainless steel is preferable as materials for the stirring shaft 122, stirring blade 124, baffle 130, serpentine cooling tube 140, and serpentine cooling tube 150. These materials are excellent in thermal conductivity and corrosion resistance. Further, as a material of the inner wall surface of the reaction vessel 110, a clad steel including stainless steel is exemplified. The outer layer material of the clad steel is preferably carbon steel, and the inner layer material of the clad steel is preferably stainless steel.

(use of polymerization apparatus 100)

As described above, the polymerization apparatus 100 is used for manufacturing a polymer. The polymerization method may be suspension polymerization or emulsion polymerization. More specifically, the polymerization apparatus 100 is used for polymerizing various vinyl monomers, for example, olefins such as ethylene and propylene, vinyl halides such as vinyl chloride and vinylidene chloride, vinyl esters such as vinyl acetate, vinyl ethers such as vinyl ethyl ether, metal salts or esters of (meth) acrylic acid such as methyl methacrylate and fumaric acid, aromatic vinyl monomers such as styrene, diene monomers such as butadiene, chloroprene and isoprene, acrylonitrile, and the like to produce polymers. The polymerization apparatus 100 is particularly preferably used for polymerizing vinyl chloride or a monomer mixture based thereon to produce a polymer.

When a polymer is produced using the polymerization apparatus 100, each raw material is supplied from a supply port (not shown) of the polymerization apparatus, and at a point in time when the temperature of the reaction compound charged into the reaction vessel 110 reaches a predetermined temperature, a refrigerant flows through each of the baffle plate 130, the serpentine cooling tube 140, the serpentine cooling tube 150, and the jacket 170 to start heat removal of the reaction compound. On the other hand, the period of starting the heat removal by the reflux condenser 180 is preferably a period of time after the polymerization conversion reaches 4%, more preferably a period of time when the polymerization conversion reaches 4 to 20%.

Even in the case of producing a polymer using the polymerization apparatus 100, various polymerization conditions may be the same as those of the known polymerization conditions. Examples of the polymerization conditions include a charging ratio of a raw material or the like, a charging method of a raw material or the like, a polymerization temperature, and the like.

For example, in the case where the polymerization apparatus 100 is used to produce a vinyl chloride polymer by suspension polymerization, the charging of the aqueous medium, vinyl chloride monomer, other comonomers, dispersion aids, polymerization initiators, and the like may be performed in the same manner as in the known method for producing a vinyl chloride polymer. The polymerization conditions may be the same as those of a known method for producing a vinyl chloride polymer.

As the monomer to be polymerized, a monomer mixture mainly composed of vinyl chloride (vinyl chloride 50 mass% or more) may be used in addition to vinyl chloride alone. As the comonomer copolymerized with vinyl chloride, for example: vinyl esters such as vinyl acetate and vinyl propionate; acrylic acid esters or methacrylic acid esters such as methyl acrylate and ethyl acrylate; olefins such as ethylene and propylene; anhydrous maleic acid; acrylonitrile; styrene; vinylidene chloride; and other monomers copolymerizable with vinyl chloride.

As the dispersion aid, a compound generally used when vinyl chloride is polymerized in an aqueous medium is used. As the dispersion aid, there are exemplified: water-soluble cellulose ethers such as methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and hydroxypropyl methyl cellulose; partially saponifying polyvinyl alcohol and acrylic acid polymer; water-soluble polymers such as gelatin, etc. The dispersing aid may be used alone or in combination of 2 or more. The dispersing aid is added, for example, in an amount of 0.01 to 5 parts by mass per 100 parts by mass of the monomer to be charged.

The polymerization initiator used may be one conventionally used for polymerization of vinyl chloride. Examples of the polymerization initiator include a percarbonate compound such as diisopropyl peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate, and diethoxyethyl peroxydicarbonate; peroxyester compounds such as alpha-cumyl peroxyneodecanoate, tributyl peroxyneodecanoate, third peroxyneoheptanoate, hexyl peroxyneodecanoate, octyl peroxyneodecanoate, and the like; peroxides such as acetyl cyclohexylsulfonyl peroxide, 2, 4-trimethylpentyl 2-peroxophenoxyacetate; and azo compounds such as azobis-2, 4-dimethylvaleronitrile and azobis (4-methoxy-2, 4-dimethylvaleronitrile). The polymerization initiator may be used alone, or 2 or more kinds may be used in combination. The polymerization initiator may be added, for example, in an amount of 0.01 to 3 parts by mass per 100 parts by mass of the monomer, and preferably in an amount of 0.05 to 3 parts by mass per 100 parts by mass of the monomer.

Further, if necessary, a polymerization regulator, a chain transfer agent, a pH regulator, a buffer, a gelation improver, an antistatic agent, a scale inhibitor, etc. which are suitably used in the polymerization of vinyl chloride may be added. In addition, regarding the reduction viscosity (K value) of the vinyl chloride polymer obtained in the present invention, by using the apparatus of the present invention, a desired range of polymers, preferably 40 to 90 ranges of polymers can be obtained.

Examples of the pH adjuster or buffer include citric acid, trisodium citrate, diammonium citrate, triammonium citrate, potassium hydrogen phthalate, sodium nitrate, sodium carbonate, potassium carbonate, cesium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, barium hydroxide, disodium phosphate, dipotassium phosphate, and tripotassium phosphate. The pH adjustor or the buffer may be used alone or in combination of 2 or more.

The polymerization apparatus 100 may be an example of a reaction apparatus. The reaction vessel 110 may be an example of a reactor. The inner surface of the reaction vessel 110 may be an example of the inner wall surface of the reactor. The side surface of the reaction vessel 110 may be an example of the inner wall surface of the reactor. The flow path of the heat medium disposed in the main body 132 of the baffle 130 may be an example of the 2 nd cooling pipe. The shelf 134 of the baffle 130 may be an example of at least a portion of the baffle. The serpentine cooling tube 140 may be an example of the 1 st cooling pipe. The serpentine cooling tube 150 may be an example of the 1 st cooling pipe. 1 of the serpentine cooling tubes 140 and 1 of the serpentine cooling tubes 150 may be at least 2 of the plurality of 1 st cooling pipes. The flow path 172 may be an example of the 3 rd cooling pipe. The flow path 182 may be an example of the 3 rd cooling pipe.

Fig. 2 schematically shows an example of an internal structure disposed in the reaction vessel 110. In fig. 2, the agitator 120 is omitted for simplicity of illustration. As shown in fig. 2, the polymerization apparatus 100 includes 1 or more baffles 130, 232, 234, 236, and 238. The polymerization apparatus 100 includes, as 1 or more serpentine cooling pipes 140, a serpentine cooling pipe 242, a serpentine cooling pipe 244, a serpentine cooling pipe 246, and a serpentine cooling pipe 248. Similarly, polymerization apparatus 100 includes serpentine cooling tube 252, serpentine cooling tube 254, serpentine cooling tube 256, and serpentine cooling tube 258 as 1 or more serpentine cooling tubes 150.

Fig. 3 is a schematic cross-sectional view of an example of the reaction vessel 110. In fig. 3, serpentine cooling tube 140 is omitted for simplicity of illustration. The installation positions of the shutter 232, the shutter 234, the shutter 236, and the shutter 238 are preset for the sake of simplicity of description.

As shown in fig. 3, in the present embodiment, the reaction vessel 110 includes a straight body 312, a 1 st mirror plate 314, a 2 nd mirror plate 316, and a pedestal 318. In the present embodiment, the straight body 312 has a cylindrical shape. When the length of the straight body 312 in the extending direction (z direction in the drawing) is L and the inner diameter of the straight body 312 is D, the straight body 312 is designed such that the value of L/D is 1.0 to 3.0, for example. The straight body 312 may be designed so that the value of L/D is 1.5 to 2.5.

In the present embodiment, the 1 st mirror plate 314 is coupled to one end of the straight body 312 to form a bottom plate of the reaction vessel 110. In the present embodiment, the 2 nd mirror plate 316 is coupled to the other end of the straight body 312 to form the top plate of the reaction vessel 110. In the present embodiment, the mount 318 holds the power mechanism 126.

As shown in fig. 3, around the polymerization apparatus 100, there are disposed: a refrigerant supply pipe 332 for supplying a refrigerant from a refrigerant supply source to the reaction vessel 110; and a refrigerant return pipe 334 for returning the refrigerant after heat exchange from the supply source of the refrigerant to the reaction vessel 110. In addition, according to the embodiment shown in fig. 3, the shutter 232 and the shutter 234 are connected by the connection portion 342, and the refrigerant flowing out from the shutter 232 can flow into the shutter 234. The baffle 234 and the baffle 236 are connected by a connecting portion 344, and the refrigerant flowing out of the baffle 234 can flow into the baffle 236. Similarly, the baffle 236 and the baffle 238 are connected by the connecting portion 346, and the refrigerant flowing out of the baffle 236 can flow into the baffle 238. Details of each baffle are described below.

According to the present embodiment, the refrigerant supplied from the refrigerant supply pipe 332 to the reaction vessel 110 flows into the baffle 232, passes through the baffle 234, the baffle 236, and the baffle 238, and is discharged to the refrigerant return pipe 334. The flow method of the refrigerant is not limited to this embodiment.

For example, in another embodiment, the refrigerant supplied from the refrigerant supply pipe 332 to the reaction vessel 110 flows into the baffle 232, passes through the baffle 234, and is discharged to the refrigerant return pipe 334. The refrigerant supplied from the refrigerant supply pipe 332 to the reaction vessel 110 flows into the baffle 238, passes through the baffle 236, and is discharged to the refrigerant return pipe 334. In yet another embodiment, each of the baffles 232, 234, 236, and 238 is configured to independently control the flow rate of the refrigerant supplied to each baffle.

Fig. 4 is a schematic plan view of an example of the reaction vessel 110. In the present embodiment, (i) baffle 232, baffle 234, baffle 236, and baffle 238, (ii) serpentine cooling tube 242, serpentine cooling tube 244, serpentine cooling tube 246, and serpentine cooling tube 248, (iii) serpentine cooling tube 252, serpentine cooling tube 254, serpentine cooling tube 256, and serpentine cooling tube 258 are arranged concentrically.

In the present embodiment, serpentine cooling tube 242, serpentine cooling tube 244, serpentine cooling tube 246, and serpentine cooling tube 248 are disposed on substantially the same circumference. In the present embodiment, (i) the baffle 232, the baffle 234, the baffle 236, and the baffle 238, and (ii) the serpentine cooling tube 252, the serpentine cooling tube 254, the serpentine cooling tube 256, and the serpentine cooling tube 258 are disposed on substantially the same circumference.

That is, in the cross section at a specific position of the straight body 312, the centers of the cross sections of the baffle 232, the baffle 234, the baffle 236, and the baffle 238 are arranged on substantially the same circumference as the centers of the cross sections of the serpentine cooling tube 252, the serpentine cooling tube 254, the serpentine cooling tube 256, and the serpentine cooling tube 258. The cross section at a specific position of the straight body 312 may be a cross section obtained by cutting the reaction vessel 110 in a plane (xy plane in the drawing) perpendicular to the extending direction (z direction in the drawing) of the straight body 312 and passing through the centers of the serpentine cooling tube 252, the serpentine cooling tube 254, the serpentine cooling tube 256, and the serpentine cooling tube 258. In this case, the width of each pipe in the cross section matches the diameter of each pipe.

In the present embodiment, the baffle 232, the baffle 234, the baffle 236, and the baffle 238 are disposed at substantially symmetrical positions about the central axis of the reaction vessel 110. Serpentine cooling tube 242, serpentine cooling tube 244, serpentine cooling tube 246, and serpentine cooling tube 248 are disposed at substantially symmetrical positions about the central axis of reaction vessel 110. Serpentine cooling tube 252, serpentine cooling tube 254, serpentine cooling tube 256, and serpentine cooling tube 258 are disposed at substantially symmetrical positions about the central axis of reaction vessel 110.

As shown in fig. 4, serpentine cooling tube 252 is disposed at a position between baffles 232 and 234. Serpentine cooling tube 254 is disposed at a position between baffles 234 and 236. Serpentine cooling tube 256 is disposed at a position between baffles 236 and 238. Serpentine cooling tube 258 is disposed at a location between baffles 238 and 232. The outer circumferences of serpentine cooling tube 252, serpentine cooling tube 254, serpentine cooling tube 256, and serpentine cooling tube 258 have diameters less than the widths Bw of baffles 232, 234, 236, and 238.

In the present embodiment, the diameters of the circles in which serpentine cooling tube 242, serpentine cooling tube 244, serpentine cooling tube 246, and serpentine cooling tube 248 are arranged are smaller than the diameters of the circles in which serpentine cooling tube 252, serpentine cooling tube 254, serpentine cooling tube 256, and serpentine cooling tube 258 are arranged. According to the present embodiment, the serpentine cooling tube may be configured in multiple stages in the diameter direction of the straight body portion 312 of the reaction vessel 110. This improves the degree of freedom in the arrangement of the internal structures, for example, compared with a case where a large pipe having a circular or spiral shape is arranged in the reaction vessel 110. Thus, the polymerization apparatus 100 having excellent cooling efficiency can be manufactured.

Diameter D of virtual circle of outer circumference of serpentine cooling tube 242, serpentine cooling tube 244, serpentine cooling tube 246, and serpentine cooling tube 248 _c The size of (a) is not particularly limited, and is preferably larger than the diameter D of the rotation region of the stirring blade 124 _d 。D _c /D _d Preferably 1.1 or more, more preferably 1.2 or more.

In the present embodiment, each of serpentine cooling tube 252, serpentine cooling tube 254, serpentine cooling tube 256, and serpentine cooling tube 258 is spaced from the inner surface of straight body 312 by a distance P _C1 . Similarly, serpentine cooling tube 242, serpentine cooling tube 244, serpentine cooling tube 246, and serpentine cooling tube 248 are each spaced a distance P from the inner surface of straight body 312 _C2 . As shown in fig. 4, in the present embodiment, P _C2 >P _C1 。

The P is _C1 P _C2 The size of (2) is not particularly limited, and P is preferable _C1 The distance between the outer periphery of each serpentine cooling tube and the inner surface of the straight body 312 is 40mm or more. In addition, P may also be _C1 Setting is performed so as to be 40mm or more. At the distance or P _C1 If the thickness is less than 40mm, polymer scale may easily adhere between the inner wall surface of the reaction vessel 110 and the serpentine cooling tube 150 in the vicinity of the gas-liquid interface in the reaction vessel 110.

Likewise, the distance P between serpentine cooling tube 242 and serpentine cooling tube 252 _C Preferably 40mm or more. Distance P _C For example, by calculating the minimum value of the distance between the outer periphery of the serpentine cooling tube 242 and the outer periphery of the serpentine cooling tube 252 in the cross section. At P _C If the diameter is less than 40mm, the polymer may be easily deposited.

The distance between a specific serpentine cooling tube and the inner surface of the straight body 312 can be determined as the shortest distance between two of the cross sections perpendicular to the extending direction of the straight body 312 and passing through the center of the specific serpentine cooling tube. The distance between each serpentine cooling tube and the inner surface of the straight body 312 is determined, for example, by calculating the minimum value of the distance between the center line of each serpentine cooling tube in the extending direction and the inner surface of the straight body 312 in the cross section. In the present embodiment, the center line along the extending direction of each serpentine cooling tube is curved in an arc shape. Details of the distance are described below.

As shown in fig. 4, in the cross section at a specific position of the straight body 312, the cross sections of the serpentine cooling tube 242, the serpentine cooling tube 244, the serpentine cooling tube 246, and the serpentine cooling tube 248 have circular arc shapes. Similarly, the cross-sections of serpentine cooling tube 252, serpentine cooling tube 254, serpentine cooling tube 256, and serpentine cooling tube 258 have circular arc shapes. The shape of the cross-sections of serpentine cooling tube 242, serpentine cooling tube 244, serpentine cooling tube 246, and serpentine cooling tube 248 may be similar to the shape of the cross-sections of serpentine cooling tube 252, serpentine cooling tube 254, serpentine cooling tube 256, and serpentine cooling tube 258. For example, in the case where the cross sections of the serpentine cooling tube 242 and the serpentine cooling tube 252 have circular arc shapes, the central angle of the circular arc of the serpentine cooling tube 242 and the central angle of the circular arc of the serpentine cooling tube 252 may be substantially the same. The same applies to serpentine cooling tube 244 and serpentine cooling tube 254, serpentine cooling tube 246 and serpentine cooling tube 256, and serpentine cooling tube 248 and serpentine cooling tube 258.

In the case where the serpentine cooling tube has an arc shape, the magnitude of the center angle of the arc may be 270 degrees or less. The center angle of the arc may be 240 degrees or less, 210 degrees or less, 180 degrees or less, 150 degrees or less, 120 degrees or less, 90 degrees or less, or 60 degrees or less.

In the present embodiment, the length (arc length in the drawing) of at least one of the serpentine cooling tube 252, the serpentine cooling tube 254, the serpentine cooling tube 256, and the serpentine cooling tube 258 in the extending direction is smaller than 2/3 of the inner circumference of the straight body 312. The length in the extending direction (the arc length in the drawing) may be 1/2 or less of the inner circumference of the straight body 312, may be less than 1/3 of the inner circumference of the straight body 312, may be less than 1/4 of the inner circumference of the straight body 312, may be less than 1/6 of the inner circumference of the straight body 312, or may be less than 1/6 of the inner circumference of the straight body 312.

As described above, the coil-shaped cooling tube described in japanese patent application laid-open No. 7-233206 has a substantially circular shape. That is, the center angle of the arc of the cooling tube is almost 360 degrees. Therefore, the baffle plate and the coil-shaped cooling pipe cannot be arranged on substantially the same circumference. In contrast, according to the present embodiment, at least 1 of the 1 or more serpentine cooling tubes 150 disposed further inside the straight body 312 than the serpentine cooling tube 140 can be disposed between 2 baffles 130 by having the above-described configuration. Thus, the serpentine cooling tube 150 may have less impact on the mixing performance of the polymerization apparatus 100 and may increase the heat transfer area of the overall apparatus.

The inner surface of the straight body 312 may be an example of the inner wall surface of the reactor. The serpentine cooling pipe 252 may be an example of the 1 st cooling pipe having the smallest distance from the inner wall surface of the reactor. The serpentine cooling tube 254 may be an example of the 1 st cooling pipe having the smallest distance from the inner wall surface of the reactor. The serpentine cooling pipe 256 may be an example of a 1 st cooling pipe having the smallest distance from the inner wall surface of the reactor. The serpentine cooling tube 258 may be an example of the 1 st cooling pipe having the smallest distance from the inner wall surface of the reactor.

(example of another embodiment)

In this embodiment, an example of the polymerization apparatus 100 will be described taking as an example a case where the serpentine cooling tube is layered in 2 layers from the center of the straight body 312 to the outside. However, the polymerization apparatus 100 is not limited to the present embodiment. In another embodiment, the serpentine cooling tube may be layered in 3 layers or more from the center of the straight body 312 to the outside. Preferably, the serpentine cooling tube is multilayered from 2 to 5 layers from the center of the straight body 312 to the outside.

Fig. 5 schematically shows an example of the internal structure of the shutter 232. The baffles 234, 236, and 238 also have the same internal structure as the baffles 232. In the present embodiment, the baffle 232 has a double-layer tube structure including an inner tube 510 and an outer tube 520. The baffle 232 has an inflow port 512 through which the refrigerant flows into the inner tube 510, and an outflow port 522 through which the refrigerant flows out of the outer tube 520.

In the present embodiment, the inlet 512 of the shutter 232 is connected to the refrigerant supply pipe 332 via the pipe 532 and the flow rate adjustment valve 542. Thereby, the flow rate of the refrigerant flowing into the damper 232 is adjusted by adjusting the opening degree of the flow rate adjustment valve 542. Similarly, the inlet 512 of the baffle 234 is connected to the refrigerant supply pipe 332 via a pipe 534 and a flow rate adjustment valve 544.

In the present embodiment, the outflow port 522 of the baffle 232 is connected to the refrigerant return pipe 334 and the baffle 234 via the connection portion 342. As shown in fig. 5, in the present embodiment, the coupling portion 342 includes a pipe 552, a flow rate adjustment valve 554, a pipe 556, and a flow rate adjustment valve 558.

The pipe 552 connects the outflow port 522 and the refrigerant return pipe 334. The flow rate adjustment valve 554 is disposed midway in the piping 552 and adjusts the flow rate of the refrigerant flowing through the piping 552. The pipe 556 connects the outflow port 522 and the baffle 234. More specifically, the pipe 556 connects a position on the pipe 552, between the flow rate adjustment valve 554 and the outlet 522 of the baffle 232, and a position on the pipe 534, between the flow rate adjustment valve 544 and the inlet 512 of the baffle 234. The flow rate adjustment valve 558 is disposed midway in the pipe 556, and adjusts the flow rate of the refrigerant flowing through the pipe 556.

(example of another embodiment)

In the present embodiment, an example of the polymerization apparatus 100 will be described in which the baffle 232 has a double-pipe structure, and the refrigerant flowing in from below the baffle 232 flows out from below the baffle 232 and flows in from below the baffle 234 to the baffle 234. However, the polymerization apparatus 100 is not limited to the present embodiment.

In another embodiment, the piping may be configured such that the refrigerant flowing in from below the baffle 232 flows out from above the baffle 232 and flows in from above the baffle 234 to the baffle 234. In yet another embodiment, the baffle 232 may also be a single layer tube.

Fig. 6 schematically shows an example of the structure of the serpentine cooling tube 252. The other serpentine cooling tube 140 and the serpentine cooling tube 150 have the same structure as the serpentine cooling tube 252. As shown in fig. 6, serpentine cooling tube 252 is repeatedly bent and extends in the z-direction. In the present embodiment, the serpentine cooling tube 252 has a serpentine portion 610. The meandering portion 610 has a plurality of extending portions 612 and 1 or more bending portions 614.

In serpentine cooling tube 252 illustrated in fig. 6, serpentine portion 610 has 15 extensions 612 and 14 bends 614. The number of extensions 612 in a single serpentine portion 610 is sometimes referred to as the number of stages. As shown in fig. 6, in the present embodiment, the serpentine cooling tube 252 extends in the xy plane in the extension portion 612 and is bent in the z direction in the bent portion 614.

In the present embodiment, the plurality of extending portions 612 extend on substantially the same plane. For example, even when the extension portion 612 is designed to extend on the same plane, the extension portion 612 may not extend entirely on the same plane due to manufacturing errors, mounting errors, or the like. In this case, the extension 612 may be considered to extend on substantially the same plane. In addition, it should be noted that the case where the extension portions 612 extend on substantially the same plane is not limited to the example.

At this point, the serpentine cooling tube 252 is different from the spiral cooling pipe. By winding the cooling pipe 252, the surface area per unit installation area can be increased as compared with a case where the cooling pipe extends in a spiral shape.

As described with fig. 4, in the present embodiment, each of the plurality of extension portions 612 is curved and extends in the xy plane. Length P of each of the plurality of extending portions 612 in extending direction _L The lengths of the extending directions of the at least 2 extending portions 612 may be the same. In the present embodiment, P _L Is the length of the extension 612 in the xy plane. P (P) _L The length of the extension portion 612 in the xy plane passing through the center of the cross section of the extension portion 612 in the case where the extension portion 612 is cut by a plane substantially perpendicular to the extending direction of the extension portion 612 (in this case, a plane substantially parallel to the z direction) may be used.

As described above, P _L May be less than 2/3 of the inner perimeter of the straight body 312. In this point, the serpentine cooling tube 252 is different from the coil-shaped cooling tube described in japanese patent application laid-open No. 7-233206.

In the single meandering portion 610, more than 1/2 of the plurality of extending portions 612 have P of the extending portions 612 _L May be less than 2/3 of the inner perimeter of the straight body 312. The P is _L May be less than 1/2 of the inner circumference of the straight body 312, may be less than 1/3 of the inner circumference of the straight body 312, may be less than 1/4 of the inner circumference of the straight body 312, may be less than 1/6 of the inner circumference of the straight body 312, and may be less than 1/6 of the inner circumference of the straight body 312.

More than 2/3 of the plurality of extensions 612 have P of the extensions 612 _L May be less than 2/3 of the inner perimeter of the straight body 312. The P is _L May be less than 1/2 of the inner circumference of the straight body 312, may be less than 1/3 of the inner circumference of the straight body 312, may be less than 1/4 of the inner circumference of the straight body 312, may be less than 1/6 of the inner circumference of the straight body 312, and may be less than 1/6 of the inner circumference of the straight body 312.

In one embodiment, at least 1 of the plurality of extensions 612 extends in a curved manner in substantially the same plane. For example, at least 1 of the plurality of extension portions 612 extends along an arc or an elliptical arc virtually arranged on the xy plane. In another embodiment, at least 1 of the plurality of extensions 612 extend linearly on substantially the same plane.

In this embodiment, 2 of the plurality of extensions 612 extend in 2 planes that are substantially parallel. For example, the adjacent 2 extensions 612 extend in 2 planes that are substantially parallel. Thereby, a stepwise extending meandering portion 610 is obtained. In another embodiment, 2 of the plurality of extensions 612 may extend in 2 planes that are not parallel. For example, the adjacent 2 extensions 612 extend in 2 planes that intersect. Thereby, a zigzag extending meandering portion 610 is obtained.

In the present embodiment, 1 or more bent portions 614 connect the ends of the adjacent 2 extension portions 612, respectively. In the embodiment shown in fig. 6, 1 or more bending portions 614 each include a portion that is bent in the z direction. Thereby, the meandering portion 610 is curved and extends in the z direction. The shape of the curved portion 614 is not particularly limited. The curved portion 614 may have a continuously curved shape or a shape formed of a plurality of straight lines, and may have a shape of a cross section (sometimes referred to as a longitudinal section) obtained by cutting a surface parallel to the extending direction of the serpentine cooling tube 252 and passing through the surface at the center of the curved portion 614. As the continuously curved shape, an arc shape or an elliptical arc shape is exemplified. The curved portion 614 may include a portion having a continuously curved shape and a portion having a shape formed of 1 or more straight lines.

The diameter of the flow path of the serpentine cooling tube 252 is not particularly limited, and is preferably 10 to 200mm. The number of extension portions 612 (sometimes referred to as the number of stages) included in the single serpentine cooling tube 252 is not particularly limited, and the number of stages is preferably 2 to 70. The distance Pp between the adjacent 2 extending portions 612 (sometimes referred to as pitch) is not particularly limited, and is preferably 60mm or more. In the case where Pp is less than 60mm, polymer scale is likely to adhere.

(example of another embodiment)

In the present embodiment, an example of the serpentine cooling tube 252 is described by taking a case where the serpentine cooling tube 252 is bent and extends in the z direction as an example. However, the serpentine cooling tube 252 is not limited to the present embodiment. In another embodiment, serpentine cooling tube 252 may also be curved and extend in the x-direction or the y-direction.

In this embodiment, an example of the serpentine cooling tube 252 is described by taking an example in which the extension portion 612 extends in the xy plane and the bent portion 614 is bent in the z direction. However, the serpentine cooling tube 252 is not limited to the present embodiment. In another embodiment, the bending portion 614 may have a 1 st bending member bending in the xy plane and a 2 nd bending member bending in the z direction.

Fig. 7 schematically shows another example of the structure of the serpentine cooling tube 252. In the present embodiment, the serpentine cooling tube 252 is zigzag-shaped and extends in the z-direction. In the present embodiment, the serpentine cooling tube 252 includes a supply pipe 702, an outflow pipe 704, and a serpentine portion 710. In the present embodiment, the meandering portion 710 has a plurality of extending portions 712 and 1 or more bending portions 714.

The supply pipe 702 is used to circulate the refrigerant supplied to the serpentine portion 710. The outflow pipe 704 is used to circulate the refrigerant flowing out from the serpentine portion 710. The meandering portion 710 repeatedly bends and extends in the z-direction.

The serpentine cooling tube 252 illustrated in fig. 7 differs from the serpentine cooling tube 252 illustrated in fig. 6 in that a plurality of extensions 712 are not arranged substantially in parallel. As for the features other than the above, the serpentine cooling tube 252 illustrated in fig. 7 may have the same constitution as the serpentine cooling tube 252 illustrated in fig. 6.

Fig. 8 schematically shows another example of the structure of the serpentine cooling tube 252. In the present embodiment, the serpentine cooling tube 252 includes a supply pipe 702, an outflow pipe 704, and a serpentine portion 810. In the present embodiment, the meandering portion 810 includes a meandering portion 812, a connecting portion 822, a meandering portion 814, a connecting portion 824, and a meandering portion 816.

In the present embodiment, the meandering portion 810 repeatedly bends and extends in the z direction. In the present embodiment, the meandering portion 812 repeatedly bends and extends in the x direction. The meandering portion 812 extends in the positive direction of the x-direction, for example. In the present embodiment, the connecting portion 822 connects the meandering portion 812 and the meandering portion 814. In the present embodiment, the meandering portion 814 is repeatedly curved and extends in the x direction. The meandering portion 814 extends in a negative direction of the x-direction, for example. In the present embodiment, the connecting portion 824 connects the meandering portion 814 and the meandering portion 816. In the present embodiment, the meandering portion 816 repeatedly bends and extends in the x direction. The meandering portion 814 extends in the positive direction of the x-direction, for example.

Each of the meandering portions 812, 814, 816 has the same configuration as the meandering portion 610. For example, at least 1 of the meandering portions 812, 814, 816 has a plurality of extending portions and 1 or more bending portions. In this case, each of the plurality of extension portions may extend in the xy plane, may extend in the xz plane, or may extend in the yz plane.

Fig. 9 schematically shows an example of a main part of the polymerization apparatus 900. The polymerization apparatus 900 differs from the polymerization apparatus 100 at a point where the pitch Pp of the serpentine cooling tube 140 differs from the pitch Pp of the serpentine cooling tube 150. As for the features other than the above-described difference, the polymerization apparatus 900 may have the same constitution as the polymerization apparatus 100.

The pitch Pp of serpentine cooling tube 140 may be greater than the pitch Pp of serpentine cooling tube 150. For example, when the viscosity of the slurry flowing in the reaction vessel 110 is relatively high, the slurry flows slowly. If the flow of the slurry is slow, scale tends to adhere to the surfaces of serpentine cooling tube 140, serpentine cooling tube 150, straight body 312, etc. Suspension polymerization of vinyl chloride is exemplified as a case where the viscosity of the slurry is relatively large. Even in this case, the discharge flow generated by the stirring blade 124 reaches the serpentine cooling tube 150 and the straight body 312 with a sufficient momentum by the serpentine cooling tube 140 having a relatively large pitch Pp. This improves the flow state in the vicinity of the serpentine cooling tube 140, the serpentine cooling tube 150, the straight body 312, and the like, and prevents the adhesion of scale.

(example of another embodiment)

In another embodiment, the pitch Pp of serpentine cooling tube 140 may also be less than the pitch Pp of serpentine cooling tube 150.

Fig. 10 schematically shows an example of a main part of the polymerization apparatus 1000. The polymerization apparatus 1000 differs from the polymerization apparatus 100 in the point where the number of stages of the serpentine cooling tube 140 differs from the number of stages of the serpentine cooling tube 150. Regarding features other than the above-described differences, the polymerization apparatus 1000 may have the same configuration as the polymerization apparatus 100. Further, the polymerization apparatus 1000 may have the features of various polymerization apparatuses of other embodiments within a range not contradictory in technology.

In one embodiment, the number of stages of serpentine cooling tube 140 and serpentine cooling tube 150 is adjusted such that the position of the upper end of serpentine cooling tube 140 is below the position of the upper end of serpentine cooling tube 150. For example, when the viscosity of the slurry flowing in the reaction vessel 110 is relatively high, scale is likely to adhere to the gas-liquid interface or foam. Suspension polymerization of vinyl chloride is exemplified as a case where the viscosity of the slurry is relatively large. If foaming at the gas-liquid interface is severe, heat removal by the reflux condenser 180 is limited. Even in this case, by suppressing the height of the upper end of the serpentine cooling tube 140 disposed at a position close to the stirring blade 124, the flow of the gas-liquid interface is activated, and the adhesion and foaming of the slurry can be suppressed. The number of stages of the serpentine cooling tube 140 is preferably adjusted so that the upper end of the serpentine cooling tube 140 is positioned below the stirring blade 124 disposed at the uppermost stage.

(example of another embodiment)

In another embodiment, the number of stages of serpentine cooling tube 140 and serpentine cooling tube 150 is adjusted such that the position of the lower end of serpentine cooling tube 140 is located above the position of the lower end of serpentine cooling tube 150. In yet another embodiment, the number of stages of serpentine cooling tube 140 is adjusted in such a way that serpentine cooling tube 140 does not interfere with the rotation of stirring blade 124.

Fig. 11 schematically shows an example of a main part of the polymerization apparatus 1100. Polymerization apparatus 1100 differs from polymerization apparatus 100 in the point where serpentine cooling tube 1160 is provided between serpentine cooling tube 140 and serpentine cooling tube 150. Regarding features other than the above-described differences, the aggregation device 1100 may have the same constitution as the aggregation device 100. Furthermore, the aggregation device 1100 may have the features of the various aggregation devices of other embodiments to the extent not inconsistent with the technology.

Fig. 12 schematically shows an example of a main part of the polymerization apparatus 1200. Unlike the polymerization apparatus 100, the polymerization apparatus 1200 is different from the polymerization apparatus 100 in that the polymerization apparatus includes a serpentine cooling tube 1252 having a semicircular cross section instead of the serpentine cooling tube 252, the serpentine cooling tube 256, and the serpentine cooling tube 258. Regarding features other than the differences, the aggregation device 1200 may have the same configuration as the aggregation device 100. Further, the aggregation device 1200 may have the features of the various aggregation devices of other embodiments within a range that is not technically contradictory.

Fig. 13 schematically shows an example of a main part of the polymerization apparatus 1300. Unlike polymerization apparatus 100, polymerization apparatus 1300 includes serpentine cooling tube 1351, serpentine cooling tube 1352, serpentine cooling tube 1353, serpentine cooling tube 1354, serpentine cooling tube 1355, and serpentine cooling tube 1356 including extended portion 612 extending in a straight line instead of serpentine cooling tube 252, serpentine cooling tube 254, serpentine cooling tube 256, and serpentine cooling tube 258 including extended portion 612 extending in a curved line. The polymerization apparatus 1200 is different from the polymerization apparatus 100 in the points where the baffles 1331, 1332, 1333, 1334, 1335, and 1336 are provided. Regarding features other than the above-described differences, the polymerization apparatus 1300 may have the same constitution as the polymerization apparatus 100. Further, the polymerization apparatus 1300 may have the features of the various polymerization apparatuses of other embodiments within a range not contradictory in technology.

In the present embodiment, serpentine cooling tube 1351, serpentine cooling tube 1352, serpentine cooling tube 1353, serpentine cooling tube 1354, serpentine cooling tube 1355, and serpentine cooling tube 1356 are disposed at substantially symmetrical positions around the central axis of reaction vessel 110 on the sides of the virtual regular hexagon. The baffles 1331, 1332, 1333, 1334, 1335, and 1336 are arranged at the vertices of the virtual regular hexagon.

According to the present embodiment, the number of serpentine cooling tubes 140 is different from the number of serpentine cooling tubes 150. For example, the number of serpentine cooling tubes 140 is less than the number of serpentine cooling tubes 150. According to the present embodiment, the shape of serpentine cooling tube 140 is dissimilar to the shape of serpentine cooling tube 150. For example, the extension 612 of the serpentine cooling tube 140 extends in a curved manner, while the extension 612 of the serpentine cooling tube 150 extends in a straight line.

(example of another embodiment)

In this embodiment, an example of the polymerization apparatus 1300 will be described by taking, as an example, a case where the barrier 1331, the barrier 1332, the barrier 1333, the barrier 1334, the barrier 1335, and the barrier 1336 are arranged at the vertices of a virtual regular hexagon. However, the polymerization apparatus 1300 is not limited to the present embodiment.

In another embodiment, at least 1 of the baffles 1331, 1332, 1333, 1334, 1335, and 1336 may be disposed between the regular hexagon and the straight body 312. In still another embodiment, at least 1 of the baffles 1331, 1332, 1333, 1334, 1335, and 1336 may be disposed between the regular hexagon and an imaginary circle in which the serpentine cooling tube 242, the serpentine cooling tube 244, the serpentine cooling tube 246, and the serpentine cooling tube 248 are disposed.

According to the present embodiment, an example of the polymerization apparatus 1300 will be described taking as an example a case where the number of serpentine cooling tubes 140 is smaller than the number of serpentine cooling tubes 150. However, the polymerization apparatus 1300 is not limited to the present embodiment. In another embodiment, the number of serpentine cooling tubes 140 may be greater than the number of serpentine cooling tubes 150.

According to the present embodiment, an example of the polymerization apparatus 1300 is described taking a case where the extension portion 612 of the serpentine cooling tube 140 is bent and extended, and the extension portion 612 of the serpentine cooling tube 150 is linearly extended as an example. However, the polymerization apparatus 1300 is not limited to the present embodiment. In another embodiment, the extension 612 of the serpentine cooling tube 140 extends linearly, while the extension 612 of the serpentine cooling tube 150 extends in a curved manner.

(example of another embodiment)

In this embodiment, an example of the polymerization apparatus 1300 will be described taking as an example a case where the diameter of the virtual circle 1403 is larger than the diameter of the virtual circle 1404 and smaller than the diameter of the virtual circle 1405. However, the polymerization apparatus 1300 is not limited to the present embodiment. In another embodiment, the diameter of imaginary circle 1403 may be smaller than the diameter of imaginary circle 1404. In yet another embodiment, the diameter of the imaginary circle 1403 may be greater than the diameter of the imaginary circle 1405.

Fig. 14 schematically shows an example of a main part of the polymerization apparatus 1400. Unlike the polymerization apparatus 100, the polymerization apparatus 1400 differs from the polymerization apparatus 100 in that a virtual circle 1403 in which the baffles 232, 234, 236, and 238 are disposed is disposed between a virtual circle 1404 in which the serpentine cooling pipes 242, 244, 246, and 248 are disposed and a virtual circle 1405 in which the serpentine cooling pipes 252, 254, 256, and 258 are disposed. Regarding features other than the above-described differences, the polymerization apparatus 1400 may have the same constitution as the polymerization apparatus 100. Further, the polymerization device 1400 may have features of various polymerization devices of other embodiments within a range that is not technically contradictory.

Fig. 15 schematically shows an example of a main part of the polymerization apparatus 1500. Unlike polymerization apparatus 1400, polymerization apparatus 1500 includes baffle 232 disposed between serpentine cooling tube 242 and serpentine cooling tube 252, baffle 234 disposed between serpentine cooling tube 244 and serpentine cooling tube 254, baffle 236 disposed between serpentine cooling tube 246 and serpentine cooling tube 256, and baffle 238 disposed at a point between serpentine cooling tube 248 and serpentine cooling tube 258. Regarding features other than the differences, the aggregation device 1500 may have the same configuration as the aggregation device 1400. Further, the polymerization apparatus 1500 may have the features of various polymerization apparatuses of other embodiments within a range not contradictory in technology.

Fig. 16 schematically shows an example of a main part of the polymerization apparatus 1600. The polymerization apparatus 1600 differs from the polymerization apparatus 100 in that the serpentine cooling tube 244 and the serpentine cooling tube 248 are not provided. Regarding features other than the differences, the aggregation device 1600 may have the same configuration as the aggregation device 100. Moreover, the aggregation device 1600 may have features of various aggregation devices of other implementations to the extent not inconsistent with the technology.

For example, in the case where the viscosity of the slurry flowing inside the reaction vessel 110 is relatively large, if the serpentine cooling tube 140 and the serpentine cooling tube 150 are arranged in multiple stages in the diameter direction of the straight body 312, there is a possibility that the slurry stays in the region between the serpentine cooling tube 140 and the serpentine cooling tube 150. Suspension polymerization of vinyl chloride is exemplified as a case where the viscosity of the slurry is relatively large. In this case, by changing the number of stages in the radial direction of the serpentine cooling tube 140 and the serpentine cooling tube 150 in the circumferential direction of the straight body 312, the stagnation of the slurry can be suppressed, and the mixing of the slurry can be promoted.

Fig. 17 schematically shows an example of a main part of the aggregation system 1700. In this embodiment, the aggregation system 1700 includes the aggregation apparatus 100 and a controller 1710. In the present embodiment, the polymerization system 1700 includes a stirring system 1702. Stirring system 1702 has stirring shaft 122, stirring blade 1722, stirring blade 1724, stirring blade 1726, and power mechanism 126. The polymerization apparatus 100 described with reference to fig. 17 may have the same configuration as the polymerization apparatus 100 described with reference to fig. 1, except that the polymerization apparatus includes stirring blades 1722, 1724, and 1726 instead of the plurality of stirring blades 124.

In this embodiment, for the sake of simplicity, an example of the polymerization system 1700 and the stirring system 1702 will be described by taking as an example a case where 3 stirring blades, that is, the stirring blades 1722, the stirring blades 1724 and the stirring blades 1726, are attached to the stirring shaft 122. However, the polymerization system 1700 and the stirring system 1702 are not limited to this embodiment. In another embodiment, 2 stirring blades are mounted on the stirring shaft 122 of the polymerization system 1700 and the stirring system 1702. In another embodiment, 4 or more stirring blades are attached to the stirring shafts 122 of the polymerization system 1700 and the stirring system 1702.

As described above, the stirring shaft 122 is rotatably disposed inside the reaction vessel 110. In particular, a part of the stirring shaft 122 is disposed inside the straight body 312 of the reaction vessel 110, and the stirring shaft 122 is rotatably configured. The stirring shaft 122 is attached to the reaction vessel 110 such that the extending direction of the stirring shaft 122 substantially coincides with the extending direction of the straight body 312.

In the present embodiment, 3 stirring blades, i.e., stirring blade 1722, stirring blade 1724, and stirring blade 1726, are installed at different positions in the extending direction of stirring shaft 122. The agitating blade 1722 is installed uppermost among the plurality of agitating blades. The stirring blade 1724 is disposed between the stirring blade 1722 and the stirring blade 1726. The agitating blade 1726 is installed at the lowermost among the plurality of agitating blades.

In the present embodiment, the stirring system 1702 stirs a liquid contained in the reaction vessel 110 of the polymerization apparatus 100. Specifically, the stirring shaft 122 rotates, and the stirring blades 1722, 1724, and 1726 (sometimes simply referred to as a plurality of stirring blades) attached to the stirring shaft 122 rotate, whereby the liquid contained in the reaction vessel 110 is stirred.

In the present embodiment, the controller 1710 controls the rotation number of the stirring shaft 122. The controller 1710 controls the rotation number of the stirring shaft 122 by controlling the output of the power mechanism 126, for example. In this embodiment, the controller 1710 controls the rotation number of the stirring shaft 122 so that the rotation number of the stirring shaft 122 satisfies the relationship shown in the following expression 1.

(number 1)

N(b/d)(L/D)/n≦6.0

In equation 1, N represents the number of the plurality of stirring blades attached to the stirring shaft 122. As described above, in the present embodiment, N is 3.b represents the maximum value [ m ] of the blade widths of the plurality of stirring blades. That is, b represents the blade width of the stirring blade having the largest blade width among the stirring blades 1722, 1724, and 1726. d represents the maximum value [ m ] of the blade diameters of the plurality of stirring blades. That is, d represents the blade diameter of the stirring blade having the largest blade diameter among the stirring blades 1722, 1724, and 1726.

L represents the length [ m ] of the reaction vessel 110 in the extending direction of the straight body 312. D represents a maximum value [ m ] of diameters of a plurality of inscribed circles substantially inscribed in the straight body 312 in each section formed by a plurality of planes when the straight body 312 is cut by a plurality of planes which are substantially perpendicular to the extending direction (vertical direction in the drawing) of the straight body 312 and pass through the mounting positions of the respective stirring blades. In the case where the reaction vessel 110 has a cylindrical straight body portion 312, D is an inner diameter [ m ] of the straight body portion 312. n represents a set value of the rotation number [ rps ] of the stirring shaft 122.

This suppresses the generation of coarse particles. Whereby the particle size distribution of the polymer becomes narrow. In addition, the generation of fish eyes can be suppressed. Furthermore, the adhesion of scale can be suppressed.

The parameter represented by N (b/D) (L/D)/N represents the stirring degree of the liquid when the liquid is contained in the reaction vessel 110 at about the rated capacity of the reaction vessel 110. Thus, the parameter is sometimes referred to as a stirring parameter.

In the present embodiment, the internal volume of the reaction vessel 110 may be 40 to 300m ³ . Further, the ratio (L/D) of the length L of the straight body 312 in the extending direction to the diameter D of the inscribed circle of the straight body 312 of the reaction vessel 110 may be 1.0 to 3.0. Thus, the method can be more reliably performedThe effect determined so that the set value of the rotation number of the stirring shaft 122, the size of at least one of the plurality of stirring blades 124, and the size of the straight body 312 of the reaction vessel 110 satisfy the relationship shown in expression 1 is obtained.

The controller 1710 preferably controls the rotation number of the stirring shaft 122 so that the rotation number of the stirring shaft 122 satisfies the relationship shown in the following equation 2.

(number 2)

0.05≦N(b/d)(L/D)/n≦6.0

In expression 2, N, b, d, L, D and n are defined as in expression 1. This can further suppress the generation of coarse particles. The particle size distribution of the polymer is narrower. In addition, the generation of fish eyes can be further suppressed. In addition, the adhesion of scale can be further suppressed.

When the polymerization apparatus 100 includes 1 or more serpentine cooling pipes 140 or 1 or more serpentine cooling pipes 150 (that is, when the number of serpentine cooling pipes in the diameter direction of the straight body 312 is 1 or more), the controller 1710 preferably controls the rotation number of the stirring shaft 122 so that the rotation number of the stirring shaft 122 satisfies the relationship shown in the following equation 3.

(number 3)

0.15≦N(b/d)(L/D)/n≦5.5

In expression 3, N, b, d, L, D and n are defined as in expression 1. This can further suppress the generation of coarse particles. The particle size distribution of the polymer is narrower. In addition, the generation of fish eyes can be further suppressed. In addition, the adhesion of scale can be further suppressed.

When a structure such as a cooling pipe is disposed inside the reaction vessel 110, it is difficult to control the flow state of the liquid contained in the reaction vessel 110, as compared with a case where the structure is not disposed inside the reaction vessel 110. In particular, the serpentine cooling tube 140 and the serpentine cooling tube 150 have complicated structures, which prevent stirring of the liquid in the extending direction of the straight body 312. Therefore, in the case where the serpentine cooling tube 140 or the serpentine cooling tube 150 is disposed inside the reaction vessel 110, it is more difficult to control the stirring state of the liquid.

Therefore, when a structure such as a cooling pipe is disposed inside the reaction vessel 110, the value of the stirring parameter is preferably maintained within a narrower range (i.e., 0.15 to 5.5) than when the structure is not disposed inside the reaction vessel 110. Even when a structure such as a cooling pipe is disposed in the reaction vessel 110, if the relationship represented by the expression 3 is established, a polymer having the same quality as that of a case where a structure such as a cooling pipe is not disposed in the reaction vessel 110 can be produced.

In this case, the ratio of the distance Pp between the adjacent 2 extension portions 612 to the maximum value of the length L in the extending direction of the straight body portion 312 may be 0.5 to 15%. A minimum value P of a distance between 1 or more serpentine cooling tubes 140 or 1 or more serpentine cooling tubes 150 and an inner wall surface of the straight body 312 _C1 The ratio of the inner diameter D with respect to the straight body 312 may be 0.5 to 10%. More than 1 serpentine cooling tube 140 or more than 1 serpentine cooling tube 150 and the maximum value P of the distance from the inner wall surface of straight body 312 _C2 The ratio of the inner diameter D with respect to the straight body 312 may be 1 to 30%.

When the polymerization apparatus 100 includes 1 or more serpentine cooling pipes 140 and 1 or more serpentine cooling pipes 150 (that is, when the number of serpentine cooling pipes in the diameter direction of the straight body 312 is 2 or more), the controller 1710 preferably controls the rotation number of the stirring shaft 122 so that the rotation number of the stirring shaft 122 satisfies the relationship shown in the following expression 4.

(number 4)

0.3≦N(b/d)(L/D)/n≦5.5

In expression 4, N, b, d, L, D and n are defined as in expression 1. This can further suppress the generation of coarse particles. The particle size distribution of the polymer is narrower. In addition, the generation of fish eyes can be further suppressed. In addition, the adhesion of scale can be further suppressed. In particular, when the relationship shown in the expression 4 is established, the fish-eye generation suppressing effect is particularly remarkable.

As described above, the serpentine cooling tube 140 and the serpentine cooling tube 150 have a complicated structure, and the agitation of the liquid in the extending direction of the straight body 312 is hindered. In particular, when the number of the serpentine cooling pipes in the diameter direction of the straight body 312 is 2 or more, the degree of the impairment is remarkable.

Therefore, when the number of the serpentine cooling pipes in the diameter direction of the straight body 312 is 2 or more, the value of the stirring parameter is preferably maintained within a narrower numerical range (i.e., 0.3 to 5.5) than when the structure is not disposed inside the reaction vessel 110. Even when the number of serpentine cooling pipes in the diameter direction of the straight body 312 is 2 or more, when the relationship shown in equation 4 is established, a polymer having the same quality as that of a structure such as a cooling pipe is not disposed in the reaction vessel 110 can be produced.

In this case, the ratio of the maximum value of the distance Pp between the adjacent 2 extension portions 612 to the length L of the straight body portion 312 in the extending direction may be 0.5 to 15%. The ratio of the minimum value L1 of the distances between the 1 or more serpentine cooling tubes 140 or the 1 or more serpentine cooling tubes 150 and the inner wall surface of the straight body 312 to the inner diameter D of the straight body 312 may be 0.5 to 10%. The ratio of the maximum value L2 of the distances between 1 or more serpentine cooling tubes 140 or 1 or more serpentine cooling tubes 150 and the inner wall surface of the straight body 312 to the inner diameter D of the straight body 312 may be 1 to 30%.

Polymerization system 1700 may be an example of a reaction apparatus. Stirring system 1702 may be an example of a stirring device. The controller 1710 may be an example of a control unit or a control device. The stirring vane 1722 may be an example of the 1 st stirring vane. The stirring vane 1724 may be an example of the 3 rd stirring vane. The stirring vane 1726 may be an example of the 2 nd stirring vane. The power mechanism 126 may be an example of a drive section.

Fig. 18 schematically shows an example of the mounting position of the stirring blade on the stirring shaft 122. In this embodiment, an example of the attachment position of the stirring blade on the stirring shaft 122 will be described, taking as an example the case where the blade diameters of the stirring blade 1722, the stirring blade 1724, and the stirring blade 1726 are di, and the blade widths of the stirring blade 1722, the stirring blade 1724, and the stirring blade 1726 are bi. In another embodiment, at least 2 of the stirring blades 1722, 1724, and 1726 have different blade diameters. Further, at least 2 of the stirring blades 1722, 1724, and 1726 have different blade widths.

In fig. 18, a single-dot chain line 1820 represents the rotation axis of the stirring shaft 122. The single-dot chain line 1822 indicates the installation location of the mixing blade 1722 on the mixing shaft 122. The single-dot chain line 1824 represents the installed location of the mixing blade 1724 on the mixing shaft 122. The single-dot chain line 1826 represents the installed location of the mixing blade 1726 on the mixing shaft 122.

In the present embodiment, the minimum value of the distance between the mounting positions of the plurality of stirring blades on the stirring shaft 122 and the position corresponding to one end of the straight body 312 on the stirring shaft 122 may be 0.1 to 0.45 times the length L in the extending direction of the straight body 312. For example, the distance Z between the attachment position of the stirring blade 1722 on the stirring shaft 122 and the position 1842 on the stirring shaft 122 corresponding to the upper end 1832 of the straight body 312 is set to be 0.1 to 0.45 times the length L in the extending direction of the straight body 312.

In the present embodiment, the stirring blade 1726 on the stirring shaft 122 is disposed between the 1 st position 1852 of the stirring shaft 122 and the 2 nd position 1854 of the stirring shaft 122. The mounting position of the stirring blade 1726 on the stirring shaft 122 may be a position at a midpoint of the blade width of the stirring blade 1726 on the stirring shaft 122. In fig. 18, the attachment position of the stirring blade 1726 is shown as the intersection of the one-dot chain line 1820 and the one-dot chain line 1826.

Position 1 1852 is above position 2 1854 with the stirring shaft 122 mounted on the straight body 312. Further, position 1 1852 is located above a position 1844 on the stirring shaft 122 corresponding to the lower end 1834 of the straight body 312. The distance between position 1 and position 1852 on the stirring shaft 122 at position 1844 corresponding to the lower end 1834 of the straight body 312 may be less than 0.25 times the inner diameter D of the straight body 312.

Further, the 2 nd position 1854 is located below a position 1844 on the stirring shaft 122 corresponding to the lower end 1834 of the straight body 312 when the stirring shaft 122 is mounted on the straight body 312. The distance between position 1854 and position 1844 on stirring shaft 122 corresponding to lower end 1834 of straight body 312 may be less than 0.1 times the inner diameter D of straight body 312.

In this embodiment, the stirring blade 1724 is attached in the vicinity of the (N-1) 3 rd position obtained by equally dividing the attachment position of the stirring blade 1722 and the attachment position of the stirring blade 1726 into (N-1). In this embodiment, since n=3, the stirring blade 1724 is attached at a position where 2 is equal to the attachment position of the stirring blade 1722 and the attachment position of the stirring blade 1726. In this case, the distance C between the attachment position of the stirring blade 1722 and the attachment position of the stirring blade 1724 _ia And a distance C between the installation position of the stirring blade 1724 and the installation position of the stirring blade 1726 _ib Approximately uniform.

The distance between the stirring vane 1724 and the 3 rd position may be 0.5 times or less the ratio (D/N) of the inner diameter D of the straight body 312 to the number N of the plurality of stirring vanes. In the case where (N-2) stirring blades 1724 are disposed between the stirring blades 1722 and 1726, the maximum value of the distances between the (N-2) stirring blades 1724 and the corresponding 3 rd position may be 0.5 times or less the ratio (D/N) of the inner diameter D of the straight body 312 to the number N of the plurality of stirring blades.

The 1 st stirring vane 1724 may be one example of (N-2) 3 rd stirring vanes. The attachment position of the stirring blade 1722 may be an example of the 1 st attachment position. The attachment position of the stirring blade 1726 may be an example of the 2 nd attachment position.

Examples

Hereinafter, the present invention will be specifically described with reference to examples. The present invention is not limited to the following examples.

(polymerization conditions)

In examples 1 to 13 and comparative examples 1 to 5, deionized water, vinyl chloride monomer and a commercially available reagent were used to produce a vinyl chloride polymer by changing the presence or absence of a serpentine cooling tube in the interior of a reaction vessel, the arrangement of the serpentine cooling tube, the size of the reaction vessel and the number of revolutions of a stirring shaft. In examples 1 to 13 and comparative examples 1 to 5, the polymerization temperature and the supply temperature of the refrigerant were the same. Further, the polymerization temperature is set according to a target value of the K value of the polymer.

(evaluation)

The particle size distribution and the number of fish eyes of the polymers produced in each of examples 1 to 10 and comparative example 1 were measured. As the particle size distribution of the polymer, the mass% of the particles of the polymer passing through the 60 mesh sieve, the mass% of the particles of the polymer passing through the 100 mesh sieve, and the mass% of the particles of the polymer passing through the 200 mesh sieve were measured.

The number of fish eyes was measured in the following order. First, 100 parts by mass of a sample polymer, 50 parts by mass of di (2-ethylhexyl) phthalate (DOP), 2.0 parts by mass of a Ba/Zn stabilizer, 5.0 parts by mass of epoxidized soybean oil, 0.1 parts by mass of carbon black, and 0.5 parts by mass of titanium dioxide were mixed to obtain a compound. Next, 50g of the compound was kneaded at 145℃for 6 minutes by a roll mill, and then, the compound was separated as a 0.3mm thick sheet. Thereafter, the sheet was visually measured for 100cm ² The number of fish eyes was measured based on the number of transparent particles.

(evaluation of fouling)

Polymerization tests were repeated in each of examples 1 to 10 and comparative example 1. After completion of the polymerization test for a predetermined number of times, the surface of the inner wall surface of the reaction vessel was visually observed to confirm the presence or absence of the adhesion of the scale. In the case where the serpentine cooling tube 140 and/or the serpentine cooling tube 150 are disposed inside the reaction vessel, the surface of the serpentine cooling tube 140 and/or the serpentine cooling tube 150 is visually observed, and the presence or absence of the adhesion of the scale is confirmed.

Example 1

(Specification of polymerization apparatus 100)

In example 1, a vinyl chloride polymer was produced using the polymerization apparatus 100 shown in fig. 2. In example 1, the content of use was 80m ³ Is provided with a reaction vessel 110. The diameter of the straight body 312 of the reaction vessel 110 was 3600mm, and the length of the straight body 312 was 6800mm. The ratio of the length L of the straight body 312 to the diameter D of the straight body 312 is 1.9.

Inside the reaction vessel 110, 4 serpentine cooling pipes 140 each having an austenitic stainless steel cylindrical pipe with an outer diameter of 90mm are arranged. The distance between the center of each of the 4 serpentine cooling tubes 140 and the central axis of the reaction vessel 110 was 1360mm. The 4 serpentine cooling tubes 140 are arranged at symmetrical positions about the central axis of the reaction vessel 110. The number of stages of each of the 4 serpentine cooling tubes 140 is 12. That is, 4 serpentine cooling tubes 140 each have 12 extensions 612. In each of the 4 serpentine cooling tubes 140, the distance between adjacent extensions 612 (sometimes referred to as pitch Pp) is 400mm.

Distance P between inner wall surface of straight body 312 and serpentine cooling tube 140 _C2 The ratio of diameter D relative to straight body 312 is 12.2%. The ratio of the pitch Pp to the length L of the straight body 312 is 5.9%.

Similarly, 4 serpentine cooling pipes 150 each having an austenitic stainless steel cylindrical pipe with an outer diameter of 90mm are provided inside the reaction vessel 110. The distance between the center of each of the 4 serpentine cooling tubes 150 and the central axis of the reaction vessel 110 was 1610mm. The 4 serpentine cooling pipes 150 are arranged at symmetrical positions with respect to the central axis of the reaction vessel 110. The number of stages of each of the 4 serpentine cooling tubes 150 is 12. Further, in each of the 4 serpentine cooling tubes 150, the pitch Pp is 400mm.

The ratio of the distance L1 between the inner wall surface of the straight body 312 and the serpentine cooling tube 150 to the diameter D of the straight body 312 was 5.3%. The ratio of the pitch Pp to the length L of the straight body 312 is 5.9%.

Next, a stirring shaft 122 having 3 paddle blades attached thereto was attached to the reaction vessel 110. The rotation number of the stirring shaft 122 is determined so as to satisfy the relationship of the above equation 1. In example 1, the stirring parameter represented by N (b/D) (L/D)/N had a value of 0.22. In addition, the stirring energy applied to the contents of the reaction vessel 110 is 80 to 200 kgf.m/s.m ³ Within a range of (2).

(polymerization method)

Vinyl chloride polymer was synthesized in the following order. First, an aqueous solution of 32,900kg of deionized water, 10.5kg of partially saponified polyvinyl alcohol having a saponification degree of 80.0 mol%, 4.5kg of hydroxypropyl methylcellulose having a methoxy substitution degree of 28.5 mass% and a hydroxypropyl substitution degree of 8.9% was prepared and charged into the reaction vessel 110. Next, 30,100kg of vinyl chloride monomer was charged into the reaction vessel 110. Thereafter, the mixed solution is stirred by the stirrer 120, and the polymerization initiator a, the polymerization initiator B, and the polymerization initiator C are pumped into the reaction vessel 110 by a pump.

As the polymerization initiator a, an isoalkane solution containing di (2-ethylhexyl) peroxydicarbonate was used. The amount of bis (2-ethylhexyl) peroxydicarbonate added was 22.1kg. An isoalkane solution containing the tert-butyl peroxyneodecanoate was used as the polymerization initiator B. The amount of the added tributyl peroxyneodecanoate was 3.2kg. An isoalkane solution containing cumyl peroxyneodecanoate was used as the polymerization initiator C. The addition amount of cumyl peroxyneodecanoate was 5.0kg.

Next, hot water was introduced into the sleeve 170 to raise the temperature of the mixed solution in the reaction vessel 110 to 57 ℃. At the point in time when the temperature of the mixed solution in the reaction vessel 110 reaches 57 ℃, cooling water starts to be introduced into the baffle 130, the serpentine cooling tube 140, the serpentine cooling tube 150, and the jacket 170. Thereafter, at the point in time when the polymerization conversion rate reaches 20%, reflux condenser 180 is operated.

All cooling was stopped at a point in time when the pressure inside the reaction vessel 110 was reduced by 0.09MPa compared with the average pressure after the start of polymerization, under the condition that the temperature of the mixed solution inside the reaction vessel 110 was maintained at 57 ℃. After 18 minutes from the time of stopping all cooling, an amount of the triethylene glycol bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate ] aqueous dispersion (concentration: 40 mass%) sufficient to stop the polymerization reaction was charged into the reaction vessel 110. Thus, the polymerization reaction was completed to obtain a vinyl chloride polymer.

After the polymerization reaction was completed, the particle size distribution and the number of fish eyes of the synthesized vinyl chloride resin were measured. Further, the adhesion state of the scale was confirmed, and the polymerization test was repeated as 1 batch. After completion of the polymerization test for a predetermined number of times, the state of adhesion of the scale inside the reaction vessel 110 was visually confirmed. Table 1 shows the results of measurement of the particle size distribution of the vinyl chloride resin, the results of measurement of the number of fish eyes, and the results of confirmation of the adhesion state of the scale.

Examples 2 to 8

The vinyl chloride polymer was synthesized using the same polymerization apparatus as the polymerization apparatus 100 shown in fig. 2. In examples 2 to 8, a vinyl chloride polymer was synthesized in the same manner as in example 1, except that the size of the reaction vessel 110, the number of revolutions of the stirring shaft 122, and the amount of the charged raw materials were different. In examples 2 to 8, the ratio of the respective raw materials and the reaction temperature were adjusted in the same manner as in example 1. From the experimental results of examples 1 to 8, the relationship between the dimensions of the reaction vessel, the dimensions of the stirring blade, the set value of the rotation number of the stirring shaft, and the quality of the produced polymer can be examined.

The outline of the specifications of the polymerization apparatus of examples 2 to 8 is shown in Table 1. Table 1 shows the results of measurement of the particle size distribution, the measurement of the number of fish eyes, and the confirmation of the adhesion state of the scale of the vinyl chloride resin in examples 2 to 8.

Example 9

Vinyl chloride polymer was synthesized using the same polymerization apparatus as the polymerization apparatus 100 shown in fig. 2 except for the points where the serpentine cooling tube 140 and the serpentine cooling tube 150 were not provided. In example 9, a vinyl chloride polymer was synthesized in the same manner as in example 1, except that the size of the reaction vessel 110, the presence or absence of the serpentine cooling tube 140 and the serpentine cooling tube 150, the number of revolutions of the stirring shaft 122, and the amount of the charged raw materials were different. In example 9, the ratio of the respective raw materials and the reaction temperature were adjusted in the same manner as in example 1. Thus, the influence of the structure disposed in the reaction vessel can be examined.

An outline of the specifications of the polymerization apparatus of example 9 is shown in table 2. Table 2 shows the measurement results of the particle size distribution of the vinyl chloride resin, the measurement results of the number of fish eyes, and the confirmation results of the adhesion state of the scale in example 9.

Examples 10 to 11

Vinyl chloride polymer was synthesized using the same polymerization apparatus as the polymerization apparatus 100 shown in fig. 2 except for the point where the serpentine cooling tube 140 was not provided. In examples 10 to 11, a vinyl chloride polymer was synthesized in the same manner as in example 1, except that the size of the reaction vessel 110, the presence or absence of the serpentine cooling tube 140, the number of revolutions of the stirring shaft 122, and the amount of the charged raw materials were different. In examples 10 to 11, the ratio of the respective raw materials and the reaction temperature were adjusted in the same manner as in example 1. Thus, the influence of the structure disposed in the reaction vessel can be examined.

The outline of the specifications of the polymerization apparatus of examples 10 to 11 is shown in Table 2. Table 2 shows the measurement results of the particle size distribution of the vinyl chloride resin, the measurement results of the number of fish eyes, and the confirmation results of the adhesion state of the scale in examples 10 to 11.

Example 12

Vinyl chloride polymer was synthesized using the same polymerization apparatus as the polymerization apparatus 100 shown in fig. 2 except that the number of the serpentine cooling tube series in the diameter direction of the reaction vessel 110 was 3. In examples 10 to 11, a vinyl chloride polymer was synthesized in the same manner as in example 1, except that the size of the reaction vessel 110, the number of the serpentine cooling tube systems, the number of revolutions of the stirring shaft 122, and the amount of the raw material charged were different. In example 12, the ratio of the respective raw materials and the reaction temperature were adjusted in the same manner as in example 1. Thus, the influence of the structure disposed in the reaction vessel can be examined.

An outline of the specifications of the polymerization apparatus of example 12 is shown in table 2. Table 2 shows the measurement results of the particle size distribution of the vinyl chloride resin, the measurement results of the number of fish eyes, and the confirmation results of the adhesion state of the scale in example 12.

Example 13

Vinyl chloride polymer was synthesized using the same polymerization apparatus as the polymerization apparatus 100 shown in fig. 2 except for the point where the number of serpentine cooling pipes in the diameter direction of the reaction vessel 110 was 5 layers. In example 13, a vinyl chloride polymer was synthesized in the same manner as in example 1, except that the size of the reaction vessel 110, the number of the serpentine cooling tube systems, the number of revolutions of the stirring shaft 122, and the amount of the charged raw materials were different. In example 13, the ratio of the respective raw materials and the reaction temperature were adjusted in the same manner as in example 1. Thus, the influence of the structure disposed in the reaction vessel can be examined.

The outline of the specifications of the polymerization apparatus of example 13 is shown in table 2. Table 2 shows the measurement results of the particle size distribution of the vinyl chloride resin, the measurement results of the number of fish eyes, and the confirmation results of the adhesion state of the scale in example 13.

Comparative example 1

Vinyl chloride polymer was synthesized using the same polymerization apparatus as the polymerization apparatus 100 used in example 1 except for the point that the size of the reaction vessel 110 was different. In comparative example 1, a vinyl chloride polymer was synthesized in the same manner as in example 1, except that the size of the reaction vessel 110, the size of the stirring blade 124, and the number of rotations of the stirring shaft 122 were different. In comparative example 1, the ratio of the respective raw materials and the reaction temperature were adjusted in the same manner as in example 1.

In comparative example 1 and example 1, the L/D of the reaction vessel 110 was different. Therefore, in comparative example 1 and example 1, the flow state inside the reaction vessel 110 is different. Accordingly, in comparative example 1 and example 1, the stirring conditions under which polymerization can be continued were also different. Thus, the stirring conditions in comparative example 1 were determined by adjusting the value of b/d in equation 1 and the set value of the rotation number of the stirring shaft so that the value of b/d in comparative example 1 was larger than that in example 1. Further, the value of the stirring parameter in comparative example 1 was 6.44.

The outline of the specifications of the polymerization apparatus of comparative example 1 is shown in table 3. Table 3 shows the measurement results of the particle size distribution of the vinyl chloride resin, the measurement results of the number of fish eyes, and the confirmation results of the adhesion state of the scale in comparative example 1.

Comparative examples 2 to 5

The same polymerization apparatus as the polymerization apparatus 100 used in example 1 was used to synthesize a vinyl chloride polymer except for the size of the reaction vessel 110, and the arrangement of the serpentine cooling tube and the pitch width. In comparative examples 2 to 5, a vinyl chloride polymer was synthesized in the same manner as in example 1, except that the size of the reaction vessel 110, the arrangement and the pitch width of the serpentine cooling tube, the size of the stirring blade 124, the number of revolutions of the stirring shaft 122, and the charged amount of the raw material were different. In comparative examples 2 to 5, the ratio of the respective raw materials and the reaction temperature were adjusted in the same manner as in example 1. In comparative examples 2 to 5, the rotation number of the stirring shaft 122 was determined so that the value of the stirring parameter exceeded 6.

The outline of the specifications of the polymerization apparatus of comparative examples 2 to 5 is shown in Table 3. Table 3 shows the results of measurement of the particle size distribution of the vinyl chloride resin, the results of measurement of the number of fish eyes, and the results of confirmation of the adhesion state of the scale in comparative examples 2 to 5.

As shown in the results of examples 1 to 13, the size of the straight portion of the reaction vessel 110, the size of at least one of the plurality of stirring blades 124, and the set value of the rotation number of the stirring shaft 122 were determined so that the value of the stirring parameter was 6.0 or less, whereby the generation of coarse particles was suppressed, and a vinyl chloride resin having a good particle size distribution was synthesized. In addition, the occurrence of fish eyes can be greatly suppressed. Further, the occurrence of scale was hardly observed by visual observation.

On the other hand, as shown in comparative examples 1 to 5, if the value of the stirring parameter exceeds 6.0, coarse particles are generated, and a vinyl chloride resin having a relatively wide particle size distribution is synthesized. Further, a plurality of fish eyes are generated, and fouling to such an extent that can be easily confirmed visually is generated.

The cause of the phenomenon is not specified, and for example, the following causes are estimated. That is, the flow state in the reaction vessel 110 is affected by the L/D of the reaction vessel 110, the structure and arrangement of the internal structures disposed in the reaction vessel 110, and the like. For example, if the L/D of the reaction vessel 110 is large, b must be made large in order to ensure fluidity of the fluid inside the reaction vessel 110. On the other hand, if b becomes large, in order to maintain the amount of stirring energy added to the raw material at 80 to 200 kgf.m/s.m ³ On the left and right, the set value n of the rotation number needs to be made smaller. In this case, if the relationship represented by expression 1 or the like is not established, the fluidity of the fluid in the reaction vessel 110 is considered to be insufficient, and the polymerization is considered to be defective.

For the same reason, if the influence of the internal structure disposed inside the reaction vessel 110 on the flow state is large, it is difficult to control the stirring state. For example, when the number of the serpentine cooling tube series is 2 or more, it is difficult to control the stirring state. In this case, as shown in examples 3 to 7, the size of the straight portion of the reaction vessel 110, the size of at least one of the plurality of stirring blades 124, and the set value of the rotation number of the stirring shaft 122 are determined so that the value of the stirring parameter is 0.3 to 5.5, whereby even when the number of the serpentine cooling pipes is 2 or more, a high-quality vinyl chloride resin can be synthesized. In particular, it is known that the obtained fish eye has a large effect of suppressing the generation of fish eyes.

TABLE 1

TABLE 2

TABLE 3

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The present invention has been described above using the embodiments, but the technical scope of the present invention is not limited to the scope described in the embodiments. Those skilled in the art will appreciate that various alterations and modifications can be practiced with respect to the described embodiments. It is apparent from the description of the claims that the embodiments to which the modification or improvement is applied are also included in the technical scope of the present invention.

It should be noted that the order of execution of the respective processes of the operations, sequences, steps, and phases in the apparatus, system, program, and method shown in the claims, the description, and the drawings may be implemented in any order unless "before", etc. are specifically indicated, and if the output of the preprocessing is not used in the post-processing. The operational flows in the claims, specification, and drawings are not necessarily to be performed in that order, even though the descriptions of "first", "next", etc. are used for convenience.

[ description of reference numerals ]

100 polymerization apparatus

110 reaction vessel

120. Mixer

122. Stirring shaft

124. Stirring vane

126. Power mechanism

130. Baffle plate

132. Main body

134. Support frame

140. Serpentine cooling tube

150. Serpentine cooling tube

170. Casing pipe

172. Flow path

180. Reflux condenser

182. Flow path

232. Baffle plate

234. Baffle plate

236. Baffle plate

238. Baffle plate

242. Serpentine cooling tube

244. Serpentine cooling tube

246. Serpentine cooling tube

248. Serpentine cooling tube

252. Serpentine cooling tube

254. Serpentine cooling tube

256. Serpentine cooling tube

258. Serpentine cooling tube

312. Straight body

314 1 st mirror plate

316 2 nd mirror plate

318. Pedestal base

332. Refrigerant supply pipe

334. Refrigerant return distribution pipe

342. Connecting part

344. Connecting part

346. Connecting part

510. Inner pipe

512. Inflow port

520. Outer tube

522. Outflow opening

532. Piping arrangement

534. Piping arrangement

542. Flow regulating valve

544. Flow regulating valve

552. Piping arrangement

554. Flow regulating valve

556. Piping arrangement

558. Flow regulating valve

610. Winding part

612. Extension part

614. Bending part

702. Supply piping

704. Outflow pipe

710. Winding part

712. Extension part

714. Bending part

810. Winding part

812. Winding part

814. Winding part

816. Winding part

822. Connecting part

824. Connecting part

900. Polymerization apparatus

1000. Polymerization apparatus

1100. Polymerization apparatus

1160. Serpentine cooling tube

1200. Polymerization apparatus

1252. Serpentine cooling tube

1300. Polymerization apparatus

1331. Baffle plate

1332. Baffle plate

1333. Baffle plate

1334. Baffle plate

1335. Baffle plate

1336. Baffle plate

1351. Serpentine cooling tube

1352. Serpentine cooling tube

1353. Serpentine cooling tube

1354. Serpentine cooling tube

1355. Serpentine cooling tube

1356. Serpentine cooling tube

1400. Polymerization apparatus

1403. Imaginary circle

1404. Imaginary circle

1405. Imaginary circle

1500. Polymerization apparatus

1600. Polymerization apparatus

1700. Aggregation system

1702. Stirring system

1710. Controller for controlling a power supply

1722. Stirring vane

1724. Stirring vane

1726. Stirring vane

1820. Single-point chain line

1822. Single-point chain line

1824. Single-point chain line

1826. Single-point chain line

1832. Upper end

1834. Lower end of

1842. Position of

1844. Position of

1852. Position 1

1854. Position 2

Claims

1. A reaction apparatus includes:

a reactor having a cylindrical straight body;

a stirring shaft, a part of which is arranged in the straight body part and is rotatably configured; a kind of electronic device with high-pressure air-conditioning system

A plurality of stirring blades installed at different positions in an extending direction of the stirring shaft; and is also provided with

The plurality of stirring blades are respectively arranged at different positions in the extending direction of the stirring shaft,

the set value of the size of the straight body, the size of at least one of the plurality of stirring blades, and the rotation number of the stirring shaft satisfies the relationship shown in the following equation 1:

(number 1)

N(b/d)(L/D)/n≦6.0

(in the formula 1,

n represents the number of the plurality of stirring blades,

b represents a maximum value [ m ] of blade widths of the plurality of stirring blades,

d represents a maximum value [ m ] of blade diameters of the plurality of stirring blades,

l represents a length m of the straight body in the extending direction,

d represents a maximum value [ m ] of diameters of a plurality of inscribed circles substantially inscribed in the straight body in each section formed by the plurality of planes when the straight body is cut by the plurality of planes which are substantially perpendicular to the extending direction of the straight body and pass through the mounting positions of the plurality of stirring blades,

n represents the set value of the rotation number [ rps ] of the stirring shaft).

2. The reaction apparatus according to claim 1, wherein a set value of a size of the straight body, a size of at least one of the plurality of stirring blades, and a rotation number of the stirring shaft satisfies a relationship shown in the following expression 2:

(number 2)

0.05≦N(b/d)(L/D)/n≦6.0

(in expression 2, N, b, d, L, D and n are defined as in expression 1).

3. The reaction apparatus according to claim 1, further comprising a plurality of cooling pipes disposed inside the straight body and through which a coolant flows;

at least 2 of the plurality of cooling pipes are different in distance from the inner wall surface of the straight body portion,

the set value of the size of the straight body, the size of at least one of the plurality of stirring blades, and the rotation number of the stirring shaft satisfies the relationship shown in the following equation 3:

(number 3)

0.15≦N(b/d)(L/D)/n≦5.5

(in equation 3, N, b, d, L, D and n are defined as in equation 1).

4. The reaction apparatus according to claim 3, wherein the set value of the rotation number of the stirring shaft, the size of the straight body, the size of at least one of the plurality of stirring blades, and the size of the straight body satisfy a relationship represented by the following expression 4:

(number 4)

0.3≦N(b/d)(L/D)/n≦3.0

(in expression 4, N, b, d, L, D and n are as defined in expression 1).

5. The reaction apparatus according to claim 3, wherein each of the plurality of cooling pipes has a meandering portion that repeatedly bends and extends;

the serpentine portion includes:

a plurality of extension parts extending linearly or bending; a kind of electronic device with high-pressure air-conditioning system

And a plurality of bending parts connecting the ends of 2 adjacent extending parts.

6. The reaction device according to claim 5, wherein a ratio of a maximum value of the distance between the adjacent 2 extension portions to a length of the straight body portion in the extending direction is 0.5 to 15%.

7. The reaction apparatus according to claim 3, wherein a ratio of a minimum value of distances between the plurality of cooling pipes and the inner wall surface of the straight body portion to an inner diameter of the straight body portion is 0.5 to 10%,

the ratio of the maximum value of the distances between the plurality of cooling pipes and the inner wall surface of the straight body portion to the inner diameter of the straight body portion is 1 to 30%.

8. The reaction apparatus according to claim 1, wherein the stirring shaft is mounted to the reactor such that an extending direction of the stirring shaft substantially coincides with an extending direction of the straight body;

The minimum value of the distance between the mounting positions of the stirring blades on the stirring shaft and the position corresponding to one end of the straight body on the stirring shaft is 0.1-0.45 times of the length L of the straight body in the extending direction.

9. The reaction apparatus according to claim 8, wherein one end of the straight body is an upper end of the straight body,

the mounting position of the stirring blade mounted at the lowest part among the plurality of stirring blades on the stirring shaft is arranged between the 1 st position and the 2 nd position of the stirring shaft,

the 1 st position is positioned above the 2 nd position under the condition that the stirring shaft is arranged on the straight body part,

the distance between the 1 st position and the position on the stirring shaft corresponding to the lower end of the straight body is less than 0.25 times of the maximum value D of the diameters of the inscribed circles,

the distance between the 2 nd position and the position on the stirring shaft corresponding to the lower end of the straight body is not more than 0.1 times the maximum value D of the diameters of the inscribed circles.

10. The reaction apparatus according to claim 1, wherein a maximum value of a distance between (N-1) 3 rd positions of the plurality of stirring blades excluding (N-2) 1 st stirring blades mounted on the uppermost part and (2) nd stirring blades mounted on the lowermost part and (D/N) which is a ratio of a maximum value D of diameters of the plurality of inscribed circles to the number N of the plurality of stirring blades is 0.5 times or less, the maximum value being obtained by dividing (N-1) between (N-2) 1 st mounting positions which are mounting positions of the 1 st stirring blades and (2 nd mounting positions which are mounting positions of the 2 nd stirring blades.

11. The reaction apparatus of claim 1, wherein the internal volume of the reactor is 40 to 300m ³ ，

The ratio (L/D) of the length L of the straight body in the extending direction to the maximum value D of the diameters of the inscribed circles is 1.0-3.0.

12. The reaction device of claim 1, wherein the plurality of stirring vanes comprises paddle vanes.

13. The reaction apparatus according to claim 1, further comprising a control unit that controls the rotation number of the stirring shaft so that the rotation number of the stirring shaft satisfies the relationship shown in the expression 1.

14. A method for producing a vinyl polymer, comprising the step of polymerizing a vinyl monomer using the reaction apparatus according to any one of claims 1 to 12 to produce a vinyl polymer.

15. A control device for controlling the rotation number of a stirring shaft rotatably arranged in the reactor and provided with a plurality of stirring blades,

the reactor has a cylindrical straight body,

a part of the stirring shaft is arranged inside the straight body part,

the control device controls the rotation number of the stirring shaft so that the rotation number of the stirring shaft satisfies a relationship shown in the following expression 1:

(number 1)

N(b/d)(L/D)/n≦6.0

(in the formula 1,

n represents the number of the plurality of stirring blades,

l represents a length m of the straight body in the extending direction,

n is a set value of the rotation number [ rps ] of the stirring shaft).

16. A stirring device is provided with:

the control device of claim 15;

the stirring shaft; a kind of electronic device with high-pressure air-conditioning system

A driving unit configured to rotate the stirring shaft;

the control device controls the rotation number of the stirring shaft by controlling the output of the driving part.