Reaction device and method for producing vinyl polymer

Abstract

To provide a reaction device that has increased heat removal efficiency in order to shorten the reaction time while increasing the size of a reaction vessel.SOLUTION: The reaction device includes a reactor 110 having a cylindrical shape, and a plurality of first cooling pipes 140, 150 arranged inside the reactor for circulating a coolant. Each of the plurality of first cooling pipes has a meandering part that extends while repeatedly bending. The meandering part includes a plurality of extending parts that extend linearly or curvedly, and a plurality of bent parts that connect end parts of two adjacent extending parts among the plurality of extending parts. At least two of the plurality of first cooling pipes have different distances from the inner wall surface of the reactor. The length of at least a part of the plurality of extending parts included in the first cooling pipe that has the shortest distance from the inner wall surface of the reactor among the at least two first cooling pipes is shorter than two-thirds of the peripheral length of the inner wall surface.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a reaction apparatus and a method for producing a vinyl polymer. [Background technology]

[0002] Patent Document 1 discloses a polymerization apparatus equipped with a baffle and a serpentine pipe through which a coolant can flow. Patent Document 2 discloses a polymerization apparatus equipped with a baffle and a coiled cooling pipe through which a coolant can flow. Patent Document 3 discloses a resin synthesis apparatus equipped with a baffle through which a heat transfer medium can flow and a stirring means having a helical ribbon blade and an anchor blade. [Prior art document] [Patent documents] [Patent Document 1] Japanese Patent Application Laid-Open No. 7-233202 [Patent Document 2] Japanese Patent Application Laid-Open No. 7-233206 [Patent Document 3] JP 2013-151621 A [General Disclosure]

[0003] In a first aspect of the present invention, a reaction apparatus is provided. The reaction apparatus includes, for example, a reactor having a cylindrical shape. The reaction apparatus includes, for example, a plurality of first cooling pipes for circulating a refrigerant. In the reaction apparatus, the plurality of first cooling pipes are, for example, disposed inside the reactor. In the reaction apparatus, each of the plurality of first cooling pipes has, for example, a serpentine portion that extends while repeatedly bending. In the reaction apparatus, the serpentine portion includes, for example, a plurality of extension portions that extend linearly or curvedly. In the reaction apparatus, the serpentine portion includes, for example, a plurality of bent portions that connect the ends of two adjacent extension portions among the plurality of extension portions. In the reaction apparatus, at least two of the plurality of first cooling pipes have, for example, different distances from the inner wall surface of the reactor. In the reaction apparatus, the length of at least a part of the plurality of extension portions included in the first cooling pipe that is the shortest distance from the inner wall surface of the reactor among the at least two first cooling pipes is, for example, smaller than 2 / 3 of the circumferential length of the inner wall surface.

[0004] In any of the above reaction devices, the length of more than 1 / 2 of the multiple extensions included in the first cooling pipe that is the shortest distance from the inner wall surface of the reactor may be shorter than 2 / 3 of the periphery of the inner wall surface. In any of the above reaction devices, the ratio of the surface area of ​​the meandering portion to the internal volume of the reactor is 0.1 to 0.9 [m 2 / m 3 In any of the above reaction apparatuses, the ratio of the surface area of ​​the meandering portion to the internal volume of the reactor may be 0.5 to 0.7 [m 2 / m 3 In the above reaction apparatus, the internal volume of the reaction vessel may be 40 to 300 m 3 It may be.

[0005] Any of the above reactors may include a plurality of baffles extending substantially parallel to the extension direction of the reactor. In any of the above reactors, each of the plurality of baffles may be arranged so that at least a portion of the baffles is in contact with the inner wall surface of the reactor. In any of the above reactors, a portion of the plurality of first cooling pipes may be arranged at a position between two baffles included in the plurality of baffles and away from the inner wall surface of the reactor. In any of the above reactors, at least one of the plurality of baffles may have a second cooling pipe for circulating a coolant.

[0006] Any of the above reactors may include a reflux condenser. In any of the above reactors, the reflux condenser may include a third cooling line for circulating a coolant. Any of the above reactors may include a jacket. In any of the above reactors, the jacket may include a third cooling line for circulating a coolant. Any of the above reactors may be used for suspension polymerization.

[0007] In a second aspect of the present invention, there is provided a method for producing a vinyl polymer, which comprises, for example, polymerizing a vinyl monomer using the reaction apparatus according to the first aspect to produce a vinyl polymer.

[0008] The above summary of the invention does not list all of the necessary features of the present invention. Also, subcombinations of these features may also be inventions. [Brief description of the drawings]

[0009] [Figure 1] A schematic cross-sectional view of an example of a polymerization apparatus 100 is shown. [Diagram 2] An example of an internal structure disposed inside the reaction vessel 110 is shown generally. [Diagram 3] A schematic cross-sectional view of an example of a reaction vessel 110 is shown. [Figure 4] A schematic plan view of an example of a reaction vessel 110 is shown. [Diagram 5] An example of the internal structure of the baffle 232 is shown diagrammatically. [Figure 6] An example of the structure of the serpentine cooling pipe 252 is shown diagrammatically. [Figure 7] Another example of the structure of the serpentine cooling tube 252 is shown diagrammatically. [Figure 8] Another example of the structure of the serpentine cooling tube 252 is shown diagrammatically. [Figure 9] An example of the main part of a polymerization apparatus 900 is shown in schematic form. [Figure 10] An example of the main part of a polymerization apparatus 1000 is shown generally. [Figure 11] An example of the main part of a polymerization apparatus 1100 is shown generally. [Figure 12] An example of the main part of the polymerization apparatus 1200 is shown in schematic form. [Figure 13] An example of the main part of a polymerization apparatus 1300 is shown generally. [Figure 14] An example of the main part of a polymerization apparatus 1400 is shown in schematic form. [Figure 15] An example of the main part of a polymerization apparatus 1500 is shown generally. [Figure 16] An example of the main part of a polymerization apparatus 1600 is shown generally. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all combinations of features described in the embodiments are necessarily essential to the solution of the invention. In this specification, when a numerical range is expressed as "A to B", the expression means A or more and B or less.

[0011] (Overview of Polymerization Apparatus 100) An example of the polymerization apparatus 100 will be described in detail with reference to Figures 1, 2, 3, and 4. The polymerization apparatus 100 is used, for example, for producing a polymer. The polymerization apparatus 100 may be used for suspension polymerization.

[0012] More specifically, the polymerization apparatus 100 is used for producing a vinyl polymer. An example of a method for producing a vinyl polymer is a method having a step of polymerizing a vinyl monomer using the polymerization apparatus 100 to produce a vinyl polymer. The method for producing the 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 the vinyl polymer includes, for example, a step of initiating a polymerization reaction of the vinyl monomer to produce a vinyl polymer.

[0013] FIG. 1 shows a schematic cross-sectional view of an example of a polymerization apparatus 100. In this embodiment, the polymerization apparatus 100 includes a reaction vessel 110, an agitator 120, one or more (sometimes simply referred to as one or more) baffles 130, one or more serpentine cooling tubes 140, one or more serpentine cooling tubes 150, a jacket 170, and a reflux condenser 180. In this embodiment, the agitator 120 includes a stirring shaft 122, a stirring blade 124, and a power mechanism 126. In this embodiment, the baffle 130 includes a main body 132 and one or more supports 134. In this embodiment, the jacket 170 includes a flow path 172 for a heat medium. In this embodiment, the reflux condenser 180 includes a flow path 182 for a heat medium.

[0014] In this embodiment, the stirring shaft 122 and the stirring blades 124 are disposed inside the reaction vessel 110. In this embodiment, each of the one or more baffles 130 is disposed inside the reaction vessel 110. In this embodiment, each of the one or more serpentine cooling tubes 140 is disposed inside the reaction vessel 110. In this embodiment, each of the one or more serpentine cooling tubes 150 is disposed inside the reaction vessel 110.

[0015] In this embodiment, the power mechanism 126 is disposed outside the reaction vessel 110. In this embodiment, the jacket 170 is disposed outside the reaction vessel 110. In this embodiment, the reflux condenser 180 is disposed outside the reaction vessel 110.

[0016] In this embodiment, the serpentine cooling pipe 140 and the serpentine cooling pipe 150 are arranged so as to have different distances from the inner surface of the reaction vessel 110. Specifically, the serpentine cooling pipe 150 is arranged at a position closer to the side surface of the reaction vessel 110 than the serpentine cooling pipe 140. In this case, the distance L2 between the serpentine cooling pipe 140 and the side surface of the reaction vessel 110 is greater than the distance L1 between the serpentine cooling pipe 150 and the side surface of the reaction vessel 110.

[0017] A distance L2 between the serpentine cooling tube 140 and the side of the reaction vessel 110 may be the minimum value of the distance between the center of the cross section of the serpentine cooling tube 140 and the side of the reaction vessel 110. A distance L1 between the serpentine cooling tube 150 and the side of the reaction vessel 110 may be the minimum value of the distance between the center of the cross section of the serpentine cooling tube 150 and the side of the reaction vessel 110. For example, when the serpentine cooling tube 140 or the serpentine cooling tube 150 is a circular tube, the cross section of the serpentine cooling tube 140 or the serpentine cooling tube 150 is a circular tube, and the center of the cross section of the serpentine cooling tube 140 or the serpentine cooling tube 150 is the center of the circle.

[0018] As a result, according to this embodiment, heat inside the reaction vessel 110 can be efficiently removed. For example, when the polymerization apparatus 100 is used for producing a polymer, the polymerization apparatus 100 can efficiently remove reaction heat generated in a polymerization reaction.

[0019] Incidentally, in suspension polymerization of vinyl chloride monomers or monomer mixtures mainly composed of vinyl chloride compounds (both may be collectively referred to as vinyl chloride monomers), when internal structures such as a cooling coil and a draft tube are provided inside the reaction vessel 110, the power required for the agitator 120 increases. In addition, the shape, size and installation position of the internal structures affect the mixing performance of the polymerization apparatus 100. Therefore, depending on the internal structures, slow flow areas may occur inside the reaction vessel 110. If slow flow areas occur inside the reaction vessel 110, the temperature inside the reaction vessel 110 becomes non-uniform. As a result, the particle size and / or degree of polymerization of the produced polymer may become non-uniform, or polymer scale may easily adhere to the inner wall of the reaction vessel 110 or the surface of the internal structure. The scale may cause fish eyes that impair the quality of molded products using the polymer.

[0020] Furthermore, under the same heat removal efficiency conditions, there is a trade-off between increasing the size of the reaction vessel 110 and shortening the reaction time. Therefore, in order to increase the size of the reaction vessel 110 while shortening the reaction time, it is desirable to increase the heat removal efficiency of the polymerization apparatus 100.

[0021] One method for increasing the heat removal efficiency of the polymerization apparatus 100 is to lower the temperature of the coolant. However, lowering the temperature of the coolant increases the production cost of the polymer. Another method for increasing the heat removal efficiency of the polymerization apparatus 100 is to increase the amount of heat removed by the jacket 170 or the reflux condenser 180. In particular, 3 In the case of a large-scale polymerization vessel as described above, the amount of heat removal by the jacket 170 alone is insufficient, so it is considered to greatly increase the amount of heat removal by the reflux condenser 180. However, if the heat removal load of the reflux condenser 180 is increased, the amount of foaming of the polymer slurry inside the reaction vessel 110 may increase. If the amount of foaming of the polymer slurry increases, the heat removal capacity of the reflux condenser 180 may decrease, or polymer scale may adhere to the inside of the reflux condenser 180.

[0022] In addition, for example, when the capacity of the polymerization vessel is increased using the polymerization vessel described in Patent Document 1, if the heat transfer area of ​​the serpentine pipe is insufficient, it may be difficult to shorten the reaction time while maintaining the quality of the product. On the other hand, in the polymerization vessel described in Patent Document 2, the heat transfer area can be increased by a relatively simple structure. However, due to the structure of the vessel, the baffle and the coiled cooling tube cannot be arranged on approximately the same circumference. Therefore, the ratio of the area in which the coiled cooling tube can be installed to the capacity of the vessel is relatively small. When the capacity of the polymerization vessel is increased using the polymerization vessel described in Patent Document 2, if the distance between the coiled cooling tubes is reduced to increase the heat transfer area, the mixing performance of the polymerization vessel may decrease. In addition, if scale or clumped reactants are generated on the surface of the coiled cooling tube due to disturbances, etc., the work inside the vessel becomes complicated, making it difficult to sufficiently remove the scale, etc.

[0023] In contrast, according to the polymerization apparatus 100 of this embodiment, the serpentine cooling pipe 140 and the serpentine cooling pipe 150 are arranged so that the distances from the inner surface of the reaction vessel 110 are different. This allows the heat transfer area to be increased using a relatively simple structure that has little effect on the mixing performance of the polymerization apparatus 100. In addition, according to the polymerization apparatus 100 of this embodiment, the degree of freedom regarding the installation positions of the serpentine cooling pipe 140 and the serpentine cooling pipe 150 is large. For example, at least one of the one or more serpentine cooling pipes 140 and the one or more serpentine cooling pipes 150 and the baffle 130 can be arranged on approximately the same circumference. This allows the heat transfer area of ​​the entire apparatus to be increased while further reducing the effect of the serpentine cooling pipe 150 on the mixing performance of the polymerization apparatus 100.

[0024] (Overview of each part of the polymerization apparatus 100) In this embodiment, the reaction vessel 110 stores raw materials for a synthesis reaction. When the polymerization apparatus 100 is used for producing a polymer, for example, a polymerizable monomer, a polymerization initiator, an aqueous medium, a dispersion aid, and the like are charged into the reaction vessel 110, and then polymerization is initiated. As the dispersion aid, for example, any surfactant can be used.

[0025] The reaction vessel 110 has, for example, a tubular shape. The reaction vessel 110 may have a cylindrical shape or a rectangular tubular shape. The reaction vessel 110 is installed such that, for example, the extension direction of the reaction vessel 110 (the z direction in the figure) is the vertical direction.

[0026] Examples of the shape of a cross section (sometimes referred to as a transverse section) of the reaction vessel 110 cut along a plane (xy plane in the drawing) perpendicular to the extension direction of the reaction vessel 110 include a circle, an ellipse, a polygon, etc. The shape of the transverse section of the reaction vessel 110 may be a shape that can be substantially regarded as a circle, an ellipse, or a polygon.

[0027] The internal volume of the reaction vessel 110 is not particularly limited, but the internal volume of the reaction vessel 110 is, for example, 1 to 300 ml. 3 The lower limit of the internal volume of the reaction vessel 110 is 40 ml. 3 It may be 80m 3 may be 100m 3 It may be 120m 3 It may be 130m 3 It may be 150m 3 It may be 200m 3 It may be 250m 3 The upper limit of the internal volume of the reaction vessel 110 may be 300 ml. 3 The upper limit of the internal volume of the reaction vessel 110 is 350 ml. 3 It may be 400m 3 The larger the internal volume of the reaction vessel 110, the more advantageous the improvement in cooling capacity according to this embodiment.

[0028] The internal capacity of the reaction vessel 110 is determined as the capacity when the reaction vessel 110 stores liquid up to a predetermined upper limit position of the reaction vessel 110. The internal capacity of the reaction vessel 110 is, for example, the internal volume of the reaction vessel 110 when no internal structure such as a stirring shaft, blades, baffles, coils, etc. is disposed inside the reaction vessel 110.

[0029] As described above, there is a trade-off between increasing the size of the reaction vessel 110 and shortening the reaction time. 3 If the internal volume of the reaction vessel 110 is more than 80 m, the heat removal efficiency of the polymerization apparatus 100 becomes insufficient, and it becomes difficult to shorten the reaction time while increasing the size of the reaction vessel 110. 3 In the above cases, the effects of the polymerization apparatus 100 according to this embodiment are more pronounced. The details of the reaction vessel 110 will be described later.

[0030] In this embodiment, the agitator 120 agitates the liquid stored inside the reaction vessel 110. In this embodiment, the agitator shaft 122 holds the agitator blade 124 and rotates the agitator blade 124. In this embodiment, the agitator blade 124 is attached to the agitator shaft 122 and agitates the liquid stored inside the reaction vessel 110.

[0031] The shape of the agitating blade 124 is not particularly limited, but examples of the shape of the agitating blade 124 include Pfaudle blades, blue margin blades, paddle blades, inclined paddle blades, turbine blades, propeller blades, and combinations thereof. As a result, when the agitating shaft 122 rotates, a discharge flow is generated that radially moves from the agitating shaft 122 toward the outer periphery. The number of blades that the agitating blade 124 has is not particularly limited, but examples of the number of blades are 2 to 6. The installation position and the installation number of the agitating blades 124 are not particularly limited, but it is preferable that the agitating blades 124 are installed in multiple stages. Examples of the number of stages of the agitating blades 124 are 2 to 6 stages.

[0032] In this embodiment, the power mechanism 126 rotates the agitation shaft 122. The power mechanism 126 includes, for example, a power unit (not shown) that generates power, and a power transmission unit (not shown) that transmits the power generated by the power unit to the agitation shaft 122. An example of the power unit is an electric motor. An example of the power transmission unit is a reducer.

[0033] The rotation speed of the stirring shaft 122, and the shape, size, number of blades, installation position, installation quantity, and installation interval Pi of the stirring blades 124 are appropriately determined according to the application of the polymerization apparatus 100. The rotation speed of the stirring shaft 122, and the shape, size, number of blades, installation position, installation quantity, and installation interval Pi of the stirring blades 124 are determined in consideration of, for example, the capacity of the reaction vessel 110, the shape of the reaction vessel 110, the internal structure disposed inside the reaction vessel 110, the configuration of the heat removal means, the heat removal capacity, and the composition of the raw materials charged for polymerization.

[0034] For example, when the polymerization apparatus 100 is used for suspension polymerization, the stirring energy applied to the contents (in this case, an aqueous suspension mixture) is 80 to 200 kgf m / s m 3 The rotation speed of the agitator shaft 122 is determined so that the agitation energy is equal to or greater than the energy A applied to the agitator drive motor disposed in the power mechanism 126 during operation of the polymerization apparatus 100. The agitation energy is determined as the net energy required for agitation per unit amount of the contents (sometimes referred to as unit content amount), calculated by subtracting various energy losses B, such as motor efficiency, conduction loss, and mechanical loss, from the energy A applied to the agitator drive motor disposed in the power mechanism 126 during operation of the polymerization apparatus 100. Examples of the unit amount include unit mass and unit volume. For example, when the volume of the contents is C, the agitation energy is calculated by the following formula (1). (Formula 1) (AB) / C [kgf m / s m 3 ]

[0035] The energy applied to the drive motor for the agitator can be electrically measured using a measuring device such as a wattmeter. The agitation energy can be easily adjusted by changing the rotation speed of the agitator shaft 122.

[0036] The rotation speed of the stirring shaft 122 in the polymerization apparatus 100 is determined, for example, based on a polymerization test carried out in advance in a pilot plant. In general, the scale-up from a pilot plant to the polymerization apparatus 100 is carried out so that the stirring state of the polymerization apparatus 100 is approximately the same as that of the pilot plant. For example, in the pilot plant and the polymerization apparatus 100, the shape, size and arrangement of each internal structure are determined so 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 and the serpentine cooling tube 150.

[0037] Therefore, according to one embodiment, the rotation speed of the stirring shaft 122 in the polymerization apparatus 100 can be determined so that the stirring energy in the polymerization apparatus 100 and the stirring energy in the pilot plant are substantially the same. As described above, the stirring energy is calculated as, for example, "(AB) / C". As a method for determining the rotation speed of the stirring shaft 122 based on the stirring energy, any known method can be adopted.

[0038] The rotation speed of the stirring shaft 122 in the pilot plant is determined, for example, by the following procedure. For example, a relationship between the rotation speed of the stirring shaft 122 in the pilot plant and the quality of the polymer is obtained by a polymerization test using the pilot plant. This determines the rotation speed of the stirring shaft 122 that will produce a polymer of the desired quality. The above quality is not particularly limited, and an example of the above quality is the particle size.

[0039] Specifically, in a polymerization test using a pilot plant, the polymerization temperature is set according to the reduced viscosity (sometimes referred to as K value) of the target polymer. Here, there is a correlation between the polymerization temperature and the average degree of polymerization of the polymer, and the K value of the polymer is widely used as an index representing the average degree of polymerization of the polymer.

[0040] In addition, in a polymerization test using a pilot plant, the polymerization time is determined according to the heat removal capacity of the pilot plant. For example, the polymerization time is determined according to (i) the amount of monomers charged as starting materials, (ii) the amount of polymerization initiator charged, and (iii) the heat removal capacity of the pilot plant, so that the amount of heat generated by the reaction does not exceed the heat removal capacity of the pilot plant.

[0041] In this way, when the polymerization time is set so that the pilot plant has sufficient heat removal capacity, a polymer having a target average degree of polymerization can be produced by setting the polymerization temperature according to the target value of the K value. Thus, for example, polymerization tests are carried out under a plurality of conditions in which the polymerization temperature and polymerization time are the same, but the rotation speed of the stirring shaft 122 is different.

[0042] The relationship between the rotation speed of the agitator shaft 122 in the pilot plant and the quality of the polymer is obtained based on the results of a plurality of tests with different rotation speeds of the agitator shaft 122. If the target value of the polymer quality is determined in this way, the rotation speed of the agitator shaft 122 that will produce a polymer of the desired quality can be determined.

[0043] When the polymerization time is set so that the pilot plant has sufficient heat removal capacity, a polymer having a desired average degree of polymerization can be produced by setting the polymerization temperature according to the target value of the K value. On the other hand, when the heat removal capacity of the pilot plant is insufficient for the set polymerization time, the polymerization temperature rises due to heat generated by the polymerization reaction. As described above, there is a correlation between the polymerization temperature and the average degree of polymerization of the produced polymer. Therefore, when the polymerization temperature rises, the error between the K value of the produced polymer and the target value of the K value increases. In addition, depending on the degree of rise in the polymerization temperature, it may become impossible to control the reaction.

[0044] In this way, the K value of the produced polymer can be used as an index regarding the heat removal capacity of the polymerization apparatus 100. For example, in the case where a polymer is produced using the polymerization apparatus 100, when a target K value is obtained for a set polymerization time, it can be determined that the polymerization apparatus 100 has sufficient heat removal capacity.

[0045] As described above, the scale-up from the pilot plant to the polymerization apparatus 100 can be performed so that the stirring state of the polymerization apparatus 100 and the stirring state of the pilot plant are approximately the same. For example, when the ratio of the size of each internal structure disposed inside the reaction vessel 110 to the inner diameter and / or the straight body height of the reaction vessel 110 in the target polymerization apparatus 100 is approximately the same as the ratio of the size of each internal structure in the pilot plant to the inner diameter and / or the straight body height of the reaction vessel in the pilot plant, and when the stirring energy in the polymerization apparatus 100 and the stirring energy in the pilot plant are approximately the same, the stirring state of the scaled-up polymerization apparatus 100 is approximately the same as the stirring state of the pilot plant.

[0046] For example, the size of the baffle 130 in the target polymerization apparatus 100 is determined so that the ratio of the length of the baffle 130 in the extension direction (vertical direction in the figure) to the height of the straight body of the reaction vessel 110 is approximately the same between the pilot plant and the target polymerization apparatus 100. The size of the baffle 130 in the target polymerization apparatus 100 is determined so that the ratio of the length of the baffle 130 in the direction approximately perpendicular to the extension direction (horizontal direction in the figure) to the inner diameter (sometimes referred to as the inner diameter) of the reaction vessel 110 is approximately the same between the pilot 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 approximately the same between the pilot plant and the target polymerization apparatus 100. The same applies to other structures (for example, the stirring blades 124, the serpentine cooling pipes 140, the serpentine cooling pipes 150, etc.).

[0047] Furthermore, as described above, once the target value of the polymer quality in the scaled-up polymerization apparatus 100 is determined, the rotation speed of the agitator shaft 122 in the scaled-up polymerization apparatus 100 can be determined based on the relationship between the rotation speed of the agitator shaft 122 in the pilot plant and the polymer quality described above. Specifically, first, the rotation speed of the agitator shaft 122 in the pilot plant is determined based on (i) the target value of the polymer quality in the polymerization apparatus 100, and (ii) the relationship between the rotation speed of the agitator shaft 122 in the pilot plant and the polymer quality. Next, the rotation speed of the agitator shaft 122 in the polymerization apparatus 100 is determined so that the agitation energy in the polymerization apparatus 100 and the agitation energy in the pilot plant are approximately the same.

[0048] In this way, taking into consideration (i) the shape, size, number of impellers, installation position, installation quantity and installation interval Pi of the impeller 124 of the intended polymerization apparatus 100, and (ii) the content volume of the reaction vessel 110, the shape of the reaction vessel 110 and the internal structures disposed inside the reaction vessel 110, the above-mentioned mixing energy per unit content volume [kgf m / s m 3 The rotation speed of the stirring shaft 122 in the polymerization apparatus 100 may be determined without strictly measuring the rotation speed of the stirring shaft 122 in the polymerization apparatus 100. The rotation speed of the stirring shaft 122 in the polymerization apparatus 100 may be determined based on the results of a simulation of a polymerization test.

[0049] In this embodiment, the baffle 130 improves the mixing performance of the polymerization apparatus 100. For example, the baffle 130 improves the mixing performance in the vertical direction inside the reaction vessel 110. The installation position of the baffle 130 is not particularly limited, but for example, the baffle 130 is disposed near the inner wall of the reaction vessel 110. The baffle 130 may be supported by the side wall of the reaction vessel 110. In another embodiment, the baffle 130 is supported by the top plate or bottom plate of the reaction vessel 110 and disposed near the stirring blade 124. When the polymerization apparatus 100 is used for the production of a polymer, the baffle 130 may be disposed so that the upper end of the baffle 130 is submerged in the liquid phase, or may be disposed so that the upper end of the baffle 130 is not submerged in the liquid phase.

[0050] The number of baffles 130 is preferably about 1 to 12, more preferably about 2 to 8, more preferably about 3 to 6, and even more preferably about 4 to 6. An even number of baffles 130 are preferably arranged approximately symmetrically around the extension axis (sometimes referred to as the central axis) of the reaction vessel 110. This further improves the mixing performance of the polymerization apparatus 100 and suppresses liquid retention. As a result, the generation of scale can be suppressed.

[0051] In this 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, but the main body 132 has, for example, a plate-like or cylindrical shape extending approximately parallel to the extension direction of the reaction vessel 110. When the main body 132 has a cylindrical shape, the diameter of the main body 132 may be 40 to 500 mm. The length Bh (sometimes referred to as height Bh) of the main body 132 in the extension direction (z direction in the figure) is not particularly limited.

[0052] The length Bw (sometimes referred to as width Bw) in a direction (x or y direction in the drawing) approximately perpendicular to the stretching direction of the main body 132 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%, 2.5 to 7.5%, or 3 to 7%.

[0053] When the main body 132 has a cylindrical shape, the ratio of the total value of the cross-sectional area of ​​one or more main bodies 132 each having a cylindrical shape to the cross-sectional area of ​​the straight body part of the reaction vessel 110 may be 0.4 to 3%. When the above ratio is less than 0.4%, the function as a baffle is insufficient, and vertical mixing inside the reaction vessel 110 may be insufficient. For example, when the polymerization apparatus 100 has a single baffle 130, the above ratio may be less than 0.4%. For example, in the suspension polymerization of vinyl chloride monomers, when vertical mixing inside the reaction vessel 110 becomes insufficient, the particle size distribution of the produced polymer may become broad. As a result, when the produced polymer is molded into a sheet, for example, fish eyes may increase, and the quality of the molded product may be reduced.

[0054] On the other hand, if the above ratio exceeds 3%, the power required for the agitator 120 increases excessively. Also, the fluidity of the liquid between the baffle 130 and the inner wall surface of the reaction vessel 110 may decrease. As a result, scale may easily adhere to the reaction vessel 110 or the internal structure of the reaction vessel 110. For example, if the polymerization apparatus 100 includes more than eight baffles 130, the above ratio may exceed 3% depending on the design of the polymerization apparatus 100.

[0055] The body 132 of at least one baffle 130 may have a flow path for circulating the heat transfer medium. The flow path may be formed inside the body 132, or may be disposed outside the body 132. The flow path may be a single pipe or may have a double pipe structure.

[0056] The heat medium may be a known refrigerant. Examples of the refrigerant include water, brine, freon, and other liquefied gases. When a liquefied gas is used as the refrigerant, the liquefied gas may function as the refrigerant by evaporating inside the serpentine cooling pipe 140. The linear velocity of the refrigerant may be about 0.1 to 6.0 m / s.

[0057] The main body 132 is connected to the inner wall surface of the reaction vessel 110, for example, via a support 134. The distance between the main body 132 and the inner wall surface of the polymerization apparatus 100 is preferably 40 mm or more. If the distance is less than 40 mm, polymer scale may easily adhere between the inner wall surface of the reaction vessel 110 and the baffle 130 near the gas-liquid interface inside the reaction vessel 110. Details of the main body 132 will be described later.

[0058] In this embodiment, the support 134 holds the main body 132. For example, one end of the support 134 contacts the inner wall surface of the reaction vessel 110, and the other end of the support 134 contacts the main body 132. As described above, the support 134 may 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 40 mm or more.

[0059] In this embodiment, the serpentine cooling pipe 140 has a flow path formed therein for circulating a heat medium. The serpentine cooling pipe 140 may be a single pipe. The serpentine cooling pipe 140 is disposed closer to the central axis of the reaction vessel 110 than the serpentine cooling pipe 150. The number of the serpentine cooling pipes 140 is preferably about 1 to 12, more preferably about 2 to 8, more preferably about 3 to 6, and further preferably about 4 to 6. An even number of the serpentine cooling pipes 140 are preferably disposed approximately symmetrically around the central axis of the reaction vessel 110.

[0060] The heat medium may be a known refrigerant. Examples of the refrigerant include water, brine, freon, and other liquefied gases. When a liquefied gas is used as the refrigerant, the liquefied gas may function as the refrigerant by evaporating inside the serpentine cooling pipe 140. The linear velocity of the refrigerant may be about 0.1 to 6.0 m / s.

[0061] In this embodiment, at least a part of the serpentine cooling pipe 140 extends while repeatedly bending. The length Ph of the part of the serpentine cooling pipe 140 that extends while repeatedly bending may be smaller than, substantially equal to, or larger than the length Bh of the body 132 of the baffle 130 in the extension direction (z direction in the figure). This increases the heat transfer area per installation area.

[0062] 1, the serpentine cooling pipe 140 extends substantially parallel to the extension direction of the reaction vessel 110 while repeatedly bending. In the example shown in Fig. 1, the entire serpentine cooling pipe 140 extends while repeatedly bending. The ratio of the length Ph of the portion of the serpentine cooling pipe 140 that extends while repeatedly bending to the total length Pt (not shown) of the serpentine cooling pipe 140 in the extension direction may be 0.25 or more, 0.5 or more, 0.75 or more, 0.8 or more, or 0.9 or more.

[0063] When the polymerization apparatus 100 is used for producing a polymer, the serpentine cooling pipe 140 may be arranged so that the upper end of the serpentine cooling pipe 140 is submerged in the liquid phase. If the upper part of the serpentine cooling pipe 140 is exposed to the gas phase, the heat transfer efficiency decreases and polymer scales are likely to adhere to the serpentine cooling pipe 140. At the end of the polymerization, the gas-liquid interface decreases due to liquid contraction. Therefore, it is preferable that the serpentine cooling pipe 140 is arranged at a position where there is a sufficient distance between the upper end of the serpentine cooling pipe 140 and the gas-liquid interface even at the end of the polymerization. Details of the serpentine cooling pipe 140 will be described later.

[0064] In this embodiment, the serpentine cooling pipe 150 has a flow path formed therein for circulating a heat medium. The serpentine cooling pipe 150 may be a single pipe. The serpentine cooling pipe 150 is disposed closer to the side wall of the reaction vessel 110 than the serpentine cooling pipe 140. The number of the serpentine cooling pipes 150 is preferably about 1 to 12, more preferably about 2 to 8, more preferably about 3 to 6, and even more preferably about 4 to 6. The number of the serpentine cooling pipes 150 may be the same as or different from the number of the serpentine cooling pipes 140. An even number of the serpentine cooling pipes 150 are preferably disposed approximately symmetrically around the central axis of the reaction vessel 110.

[0065] The heat medium may be a known refrigerant. Examples of the refrigerant include water, brine, freon, and other liquefied gases. When a liquefied gas is used as the refrigerant, the liquefied gas may function as the refrigerant by evaporating inside the serpentine cooling pipe 140. The linear velocity of the refrigerant may be about 0.1 to 6.0 m / s.

[0066] In this embodiment, at least a part of the serpentine cooling pipe 150 extends while repeatedly bending. The length Ph of the part of the serpentine cooling pipe 150 that extends while repeatedly bending may be smaller than, substantially equal to, or larger than the length Bh of the body 132 of the baffle 130 in the extension direction (z direction in the figure). This increases the heat transfer area per installation area.

[0067] 1, the serpentine cooling pipe 150 extends substantially parallel to the extension direction of the reaction vessel 110 while repeatedly bending. In the example shown in Fig. 1, the entire serpentine cooling pipe 150 extends while repeatedly bending. The ratio of the length Ph of the portion of the serpentine cooling pipe 150 that extends while repeatedly bending to the total length Pt (not shown) of the serpentine cooling pipe 150 in the extension direction may be 0.25 or more, 0.5 or more, 0.75 or more, 0.8 or more, or 0.9 or more.

[0068] When the polymerization apparatus 100 is used for producing a polymer, the serpentine cooling pipe 150 may be disposed so that the upper end of the serpentine cooling pipe 150 is submerged in the liquid phase. If the upper part of the serpentine cooling pipe 150 is exposed to the gas phase, the heat transfer efficiency decreases and polymer scales are likely to adhere to the serpentine cooling pipe 150. At the end of the polymerization, the gas-liquid interface decreases due to liquid contraction. Therefore, it is preferable that the serpentine cooling pipe 150 is disposed at a position where there is a sufficient distance between the upper end of the serpentine cooling pipe 150 and the gas-liquid interface even at the end of the polymerization.

[0069] In one embodiment, the flow direction of the coolant in the serpentine cooling pipe 150 is set so that the coolant flows from below the reaction vessel 110 toward above the reaction vessel 110. In another embodiment, the flow direction of the coolant in the serpentine cooling pipe 150 is set so that the coolant flows from above the reaction vessel 110 toward below the reaction vessel 110.

[0070] For example, the liquid returned from the reflux condenser 180 has a lower temperature and a higher density than the liquid inside the reaction vessel 110. Therefore, in the vicinity of the inlet for the liquid returned from the reflux condenser 180, the liquid inside the reaction vessel 110 tends to flow from the top to the bottom. Therefore, for example, the serpentine cooling pipe 150 disposed in the vicinity of the inlet for the liquid returned from the reflux condenser 180 can be configured so that the refrigerant flows from the bottom of the reaction vessel 110 to the top of the reaction vessel 110. The details of the serpentine cooling pipe 150 will be described later.

[0071] In this embodiment, the jacket 170 heats or cools the reaction vessel 110 from outside the reaction vessel 110. As described above, the jacket 170 has the flow path 172 configured to allow a heat medium to flow. The jacket 170 adjusts the amount of heat to be applied to and the amount of heat to be removed from the reaction vessel 110 by controlling at least one of the temperature and the flow rate of the heat medium flowing through the flow path 172.

[0072] The heat medium may be a known refrigerant. Examples of the refrigerant include water, brine, Freon, and various liquefied gases. A liquid refrigerant is preferably used as the refrigerant. When a liquefied gas is used as the refrigerant, the liquefied gas may function as the refrigerant by evaporating inside the serpentine cooling pipe 140. The linear velocity of the refrigerant may be about 0.1 to 6.0 m / s.

[0073] In this embodiment, the reflux condenser 180 is used to remove heat from the reaction vessel 110. For example, steam from the reaction vessel 110 is supplied to the reflux condenser 180. The reflux condenser 180 cools and liquefies the steam. The reflux condenser 180 returns the liquid generated by the cooling to the reaction vessel 110. As described above, the reflux condenser 180 has a flow path 182 configured to allow a heat medium to flow. The reflux condenser 180 cools the steam from the reaction vessel 110 by heat exchange between the heat medium flowing through the flow path 182 and the steam from the reaction vessel 110. The amount of heat removed from the reaction vessel 110 can be adjusted by controlling at least one of the temperature and flow rate of the heat medium flowing through the flow path 182.

[0074] (Heat removal methods) As described above, in this embodiment, the reaction vessel 110 has the baffle 130, the serpentine cooling tube 140, the serpentine cooling tube 150, the jacket 170, and the reflux condenser 180 as heat removal means. The ratio of the amount of heat removed by each heat removal device to the total amount of heat generated is not particularly limited. The above ratio is determined, for example, in consideration of the quality of the polymer produced, the manufacturing cost, etc. For example, the ratio of the amount of heat removed by the baffle 130 to the total amount of heat generated is preferably 10 to 30%. The ratio of the total amount of heat removed by the serpentine cooling tube 140 and the serpentine cooling tube 150 to the total amount of heat generated is preferably 10 to 50%. The ratio of the amount of heat removed by the jacket 170 to the total amount of heat generated is preferably 20 to 40%. The ratio of the amount of heat removed by the reflux condenser 180 to the total amount of heat generated is preferably 10 to 50%.

[0075] In addition, the serpentine cooling pipes 140 and 150 have a ratio of the total surface area of ​​the serpentine cooling pipes 140 and 150 to the internal volume of the reaction vessel 110 of 0.1 to 0.9 [m 2 / m 3 The ratio is preferably designed to be 0.5 to 0.7 [m 2 / m 3 This makes it possible to set the ratio of the sum of the heat removal amounts of the serpentine cooling pipes 140 and 150 to the total heat generation amount to 10 to 50%.

[0076] (Materials of Each Part of Polymerization Apparatus 100) The material of each part of the polymerization apparatus 100 is appropriately determined in consideration of mechanical strength, corrosion resistance, heat transfer, and the like. For example, the material used for the stirring shaft 122, the stirring blade 124, the baffle 130, the serpentine cooling tube 140, and the serpentine cooling tube 150 is preferably stainless steel such as high-chromium high-purity ferritic stainless steel, duplex stainless steel, and austenitic stainless steel. These materials have excellent heat transfer and corrosion resistance. In addition, the material of the inner wall surface of the reaction vessel 110 is, for example, clad steel containing stainless steel. The material of the outer layer of the clad steel is preferably carbon steel, and the material of the inner layer of the clad steel is preferably stainless steel.

[0077] (Use of the polymerization apparatus 100) As described above, the polymerization apparatus 100 is used for producing 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 ethyl vinyl ether, (meth)acrylic acid esters such as methyl methacrylate, metal salts or esters of maleic acid or fumaric acid, aromatic vinyls such as styrene, diene monomers such as butadiene, chloroprene, and isoprene, acrylonitrile, and the like to produce a polymer. The polymerization apparatus 100 is particularly suitable for use in polymerizing vinyl chloride or a monomer mixture mainly composed of vinyl chloride to produce a polymer.

[0078] 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 when the temperature of the reaction compound charged inside the reaction vessel 110 reaches a predetermined temperature, heat removal from the reaction compound is started by circulating a coolant through each of the baffle 130, the serpentine cooling tube 140, the serpentine cooling tube 150, and the jacket 170. On the other hand, the timing to start removing heat by the reflux condenser 180 is preferably after the polymerization conversion rate reaches 4%, and more preferably when the polymerization conversion rate is 4 to 20%.

[0079] Even when a polymer is produced using the polymerization apparatus 100, various polymerization conditions may be similar to known polymerization conditions. Examples of the polymerization conditions include the charging ratio of raw materials, the charging method of raw materials, and the polymerization temperature.

[0080] For example, when a vinyl chloride polymer is produced by suspension polymerization using polymerization apparatus 100, the aqueous medium, vinyl chloride monomer, and optionally other comonomers, dispersing aids, polymerization initiators, etc. are charged in the same manner as in known methods for producing vinyl chloride polymers. The polymerization conditions may also be the same as in known methods for producing vinyl chloride polymers.

[0081] As the monomer to be polymerized, vinyl chloride alone or a monomer mixture mainly composed of vinyl chloride (vinyl chloride 50% by mass or more) can be used. Examples of the comonomer to be copolymerized with vinyl chloride include 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; maleic anhydride; acrylonitrile; styrene; vinylidene chloride; and other monomers copolymerizable with vinyl chloride.

[0082] The above dispersion aid is a compound that is usually used when vinyl chloride is polymerized in an aqueous medium. Examples of the above dispersion aid include water-soluble cellulose ethers such as methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and hydroxypropyl methyl cellulose; partially saponified polyvinyl alcohol, acrylic acid polymers; and water-soluble polymers such as gelatin. The above dispersion aids may be used alone or in combination of two or more. The dispersion 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.

[0083] The polymerization initiator used may be one that has been used in the past for vinyl chloride polymerization. Examples of the polymerization initiator include percarbonate compounds such as diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, and diethoxyethyl peroxydicarbonate; perester compounds such as α-cumyl peroxyneodecanate, t-butyl peroxyneodecanate, t-butyl peroxyneoheptanoate, hexyl peroxyneodecanate, and octyl peroxyneodecanate; peroxides such as acetylcyclohexylsulfonyl peroxide and 2,4,4-trimethylpentyl-2-peroxyphenoxyacetate; and azo compounds such as azobis-2,4-dimethylvaleronitrile and azobis(4-methoxy-2,4-dimethylvaleronitrile). The polymerization initiator may be used alone or in combination of two or more. 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 is preferably added in an amount of 0.05 to 3 parts by mass per 100 parts by mass of the monomer.

[0084] Furthermore, if necessary, polymerization regulators, chain transfer agents, pH regulators, buffers, gelling improvers, antistatic agents, scale inhibitors, etc., which are appropriately used in vinyl chloride polymerization, can be added. With regard to the reduced viscosity (K value) of the vinyl chloride polymer obtained by the present invention, a polymer having a reduced viscosity in the desired range can be obtained by using the apparatus of the present invention, and preferably a polymer having a reduced viscosity in the range of 40 to 90 can be obtained.

[0085] Examples of pH adjusters or buffers include citric acid, trisodium citrate, diammonium citrate, triammonium citrate, potassium hydrogen phthalate, sodium nitrate, sodium carbonate, potassium carbonate, cesium carbonate, sodium hydrogen carbonate, sodium hydroxide, potassium hydroxide, barium hydroxide, disodium phosphate, dipotassium phosphate, tripotassium phosphate, etc. The above pH adjusters or buffers may be used alone or in combination of two or more.

[0086] 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 an inner wall surface of a reactor. The side surface of the reaction vessel 110 may be an example of an inner wall surface of a reactor. The flow path of the heat medium arranged in the main body 132 of the baffle 130 may be an example of a second cooling pipe. The support 134 of the baffle 130 may be an example of at least a part of the baffle. The serpentine cooling pipe 140 may be an example of a first cooling pipe. The serpentine cooling pipe 150 may be an example of a first cooling pipe. One of the serpentine cooling pipes 140 and one of the serpentine cooling pipes 150 may be an example of at least two of the multiple first cooling pipes. The flow path 172 may be an example of a third cooling pipe. The flow path 182 may be an example of a third cooling pipe.

[0087] FIG. 2 is a schematic diagram of an example of an internal structure disposed inside the reaction vessel 110. In FIG. 2, the agitator 120 is omitted from the illustration for the purpose of simplifying the description. As shown in FIG. 2, the polymerization apparatus 100 includes a baffle 232, a baffle 234, a baffle 236, and a baffle 238 as one or more baffles 130. The polymerization apparatus 100 also includes a serpentine cooling pipe 242, a serpentine cooling pipe 244, a serpentine cooling pipe 246, and a serpentine cooling pipe 248 as one or more serpentine cooling pipes 140. Similarly, the polymerization apparatus 100 includes a serpentine cooling pipe 252, a serpentine cooling pipe 254, a serpentine cooling pipe 256, and a serpentine cooling pipe 258 as one or more serpentine cooling pipes 150.

[0088] Fig. 3 shows a schematic cross-sectional view of an example of the reaction vessel 110. In Fig. 3, for the purpose of simplifying the explanation, the depiction of the serpentine cooling pipe 140 is omitted. Also, for the purpose of simplifying the explanation, the installation positions of the baffle 232, the baffle 234, the baffle 236, and the baffle 238 are deformed.

[0089] 3, in this embodiment, the reaction vessel 110 includes a straight body portion 312, a first end plate 314, a second end plate 316, and a base 318. In this embodiment, the straight body portion 312 has a cylindrical shape. When the length of the straight body portion 312 in the extension direction (z direction in the figure) is Hb and the inner diameter of the straight body portion 312 is Db, the straight body portion 312 is designed so that the value of Hb / Db is, for example, 1.0 to 3.0. The straight body portion 312 may be designed so that the value of Hb / Db is 1.5 to 2.5.

[0090] In this embodiment, the first end plate 314 is connected to one end of the straight body portion 312 and constitutes a bottom plate of the reaction vessel 110. In this embodiment, the second end plate 316 is connected to the other end of the straight body portion 312 and constitutes a top plate of the reaction vessel 110. In this embodiment, the base 318 holds the power mechanism 126.

[0091] As shown in FIG. 3, 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 reaction vessel 110 to the refrigerant supply source are arranged around the polymerization apparatus 100. According to the embodiment shown in FIG. 3, the baffle 232 and the baffle 234 are connected by a connecting portion 342, and the refrigerant flowing out of the baffle 232 can flow into the baffle 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 a connecting portion 346, and the refrigerant flowing out of the baffle 236 can flow into the baffle 238. Details of each baffle will be described later.

[0092] According to this embodiment, the coolant supplied from the coolant 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 coolant return pipe 334. The flow method of the coolant is not limited to this embodiment.

[0093] For example, in another embodiment, the coolant supplied from the coolant supply pipe 332 to the reaction vessel 110 flows into the baffle 232, passes through the baffle 234, and is discharged to the coolant return pipe 334. Also, the coolant supplied from the coolant supply pipe 332 to the reaction vessel 110 flows into the baffle 238, passes through the baffle 236, and is discharged to the coolant return pipe 334. In still another embodiment, each of the baffles 232, 234, 236, and 238 is configured to be able to independently control the flow rate of the coolant supplied to each baffle.

[0094] 4 shows a schematic plan view of an example of the reaction vessel 110. In this 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, and (iii) serpentine cooling tube 252, serpentine cooling tube 254, serpentine cooling tube 256, and serpentine cooling tube 258 are concentrically arranged.

[0095] In this embodiment, the serpentine cooling pipe 242, the serpentine cooling pipe 244, the serpentine cooling pipe 246, and the serpentine cooling pipe 248 are arranged on approximately the same circumference. Also, in this embodiment, (i) the baffle 232, the baffle 234, the baffle 236, and the baffle 238, and (ii) the serpentine cooling pipe 252, the serpentine cooling pipe 254, the serpentine cooling pipe 256, and the serpentine cooling pipe 258 are arranged on approximately the same circumference.

[0096] That is, in a cross section at a specific position of the straight body portion 312, the center of the cross section of the baffle 232, the baffle 234, the baffle 236, and the baffle 238 and the center of the cross section of the serpentine cooling pipe 252, the serpentine cooling pipe 254, the serpentine cooling pipe 256, and the serpentine cooling pipe 258 are arranged on approximately the same circumference. The cross section at a specific position of the straight body portion 312 may be a cross section of the reaction vessel 110 cut by a plane (xy plane in the figure) perpendicular to the extension direction (z direction in the figure) of the straight body portion 312 and passing through the centers of the serpentine cooling pipe 252, the serpentine cooling pipe 254, the serpentine cooling pipe 256, and the serpentine cooling pipe 258. In this case, the width of each pipe in the cross section corresponds to the diameter of each pipe.

[0097] In this embodiment, baffle 232, baffle 234, baffle 236, and baffle 238 are disposed at approximately symmetrical positions around the central axis of reaction vessel 110. Serpentine cooling tube 242, serpentine cooling tube 244, serpentine cooling tube 246, and serpentine cooling tube 248 are disposed at approximately symmetrical positions around 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 approximately symmetrical positions around the central axis of reaction vessel 110.

[0098] 4 , serpentine cooling tube 252 is disposed between baffle 232 and baffle 234. Serpentine cooling tube 254 is disposed between baffle 234 and baffle 236. Serpentine cooling tube 256 is disposed between baffle 236 and baffle 238. Serpentine cooling tube 258 is disposed between baffle 238 and baffle 232. The outer diameters of serpentine cooling tube 252, serpentine cooling tube 254, serpentine cooling tube 256, and serpentine cooling tube 258 may be smaller than the widths Bw of baffles 232, 234, 236, and 238.

[0099] In this embodiment, the diameter of the circle on which the serpentine cooling pipe 242, the serpentine cooling pipe 244, the serpentine cooling pipe 246, and the serpentine cooling pipe 248 are arranged is smaller than the diameter of the circle on which the serpentine cooling pipe 252, the serpentine cooling pipe 254, the serpentine cooling pipe 256, and the serpentine cooling pipe 258 are arranged. According to this embodiment, the serpentine cooling pipes can be arranged in multiple stages in the diameter direction of the straight body part 312 of the reaction vessel 110. This improves the degree of freedom in the arrangement of the internal structure, for example, compared to the case where a large ring-shaped or spiral-shaped pipe is arranged inside the reaction vessel 110. As a result, a polymerization apparatus 100 with excellent cooling efficiency can be manufactured.

[0100] The size of the diameter D1 of an imaginary circle on which the outer circumferences of the serpentine cooling pipes 242, 244, 246, and 248 are arranged is not particularly limited, but is preferably larger than the diameter D2 of the rotation region of the stirring blade 124. D1 / D2 is preferably 1.1 or more, and more preferably 1.2 or more.

[0101] In this embodiment, the distances between each of the serpentine cooling pipes 252, 254, 256, and 258 and the inner surface of the body portion 312 are all L1. Similarly, the distances between each of the serpentine cooling pipes 242, 244, 246, and 248 and the inner surface of the body portion 312 are all L2. As shown in Fig. 4, in this embodiment, L2>L1.

[0102] The above L1 and L2 are not particularly limited, but L1 is preferably set so that the distance between the outer periphery of each serpentine cooling pipe and the inner surface of the straight body portion 312 is 40 mm or more. L1 may be set to 40 mm or more. If the above distance or L1 is less than 40 mm, polymer scale may easily adhere between the inner wall surface of the reaction vessel 110 and the serpentine cooling pipe 150 near the gas-liquid interface inside the reaction vessel 110.

[0103] Similarly, the distance Pc between the serpentine cooling pipe 242 and the serpentine cooling pipe 252 is preferably 40 mm or more. The distance Pc is determined, for example, by calculating the minimum value of the distance between the outer periphery of the serpentine cooling pipe 242 and the outer periphery of the serpentine cooling pipe 252 in the above cross section. If Pc is less than 40 mm, polymer scale may easily adhere.

[0104] The distance between a specific serpentine cooling pipe and the inner surface of the straight body portion 312 may be determined as the shortest distance between them in a cross section perpendicular to the extension direction of the straight body portion 312 and passing through the center of the specific serpentine cooling pipe. The distance between each serpentine cooling pipe and the inner surface of the straight body portion 312 is determined, for example, by calculating the minimum value of the distance between the center line along the extension direction of each serpentine cooling pipe and the inner surface of the straight body portion 312 in the above cross section. In this embodiment, the center line along the extension direction of each serpentine cooling pipe is curved in an arc shape. The details of the above distances will be described later.

[0105] 4, in a cross section at a specific position of the straight body portion 312, the cross sections of the serpentine cooling pipe 242, the serpentine cooling pipe 244, the serpentine cooling pipe 246, and the serpentine cooling pipe 254 have an arc-shaped cross section. Similarly, the cross sections of the serpentine cooling pipe 252, the serpentine cooling pipe 254, the serpentine cooling pipe 256, and the serpentine cooling pipe 258 have an arc-shaped cross section. The cross-sectional shapes of the serpentine cooling pipe 242, the serpentine cooling pipe 244, the serpentine cooling pipe 246, and the serpentine cooling pipe 254 and the cross-sectional shapes of the serpentine cooling pipe 252, the serpentine cooling pipe 254, the serpentine cooling pipe 256, and the serpentine cooling pipe 258 may be similar in shape. For example, when the cross sections of serpentine cooling pipe 242 and serpentine cooling pipe 252 have an arc-shaped shape, the central angle of the arc of serpentine cooling pipe 242 may be substantially the same as the central angle of the arc of serpentine cooling pipe 252. The same may be true for serpentine cooling pipe 244 and serpentine cooling pipe 254, serpentine cooling pipe 246 and serpentine cooling pipe 256, and serpentine cooling pipe 248 and serpentine cooling pipe 258.

[0106] When the shape of the serpentine cooling pipe is an arc, the magnitude of the central angle of the arc may be 270 degrees or less, 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.

[0107] In this embodiment, the length in the extension direction of at least one of the serpentine cooling pipes 252, 254, 256, and 258 (the length of the arc in the drawing) is smaller than 2 / 3 of the length of the inner circumference of the straight body portion 312. The length in the extension direction (the length of the arc in the drawing) may be 1 / 2 or less of the length of the inner circumference of the straight body portion 312, may be smaller than 1 / 2 of the length of the inner circumference of the straight body portion 312, may be smaller than 1 / 3 of the length of the inner circumference of the straight body portion 312, may be smaller than 1 / 3 of the length of the inner circumference of the straight body portion 312, may be 1 / 4 or less of the length of the inner circumference of the straight body portion 312, may be smaller than 1 / 4 of the length of the inner circumference of the straight body portion 312, may be 1 / 6 or less of the length of the inner circumference of the straight body portion 312, or may be smaller than 1 / 6 of the length of the inner circumference of the straight body portion 312.

[0108] As described above, the coiled cooling pipe described in JP-A-7-233206 has a substantially circular shape. That is, the central angle of the arc of the cooling pipe is approximately 360 degrees. Therefore, the baffle and the coiled cooling pipe cannot be arranged on approximately the same circumference. In contrast, according to the present embodiment, at least one of the one or more serpentine cooling pipes 150 arranged at a position closer to the inside of the straight body portion 312 than the serpentine cooling pipe 140 has the above-mentioned configuration and can be arranged between the two baffles 130. This makes it possible to increase the heat transfer area of ​​the entire apparatus while reducing the effect of the serpentine cooling pipe 150 on the mixing performance of the polymerization apparatus 100.

[0109] The inner surface of the straight body portion 312 may be an example of an inner wall surface of a reactor. The serpentine cooling pipe 252 may be an example of a first cooling pipe having the shortest distance from the inner wall surface of the reactor. The serpentine cooling pipe 254 may be an example of a first cooling pipe having the shortest distance from the inner wall surface of the reactor. The serpentine cooling pipe 256 may be an example of a first cooling pipe having the shortest distance from the inner wall surface of the reactor. The serpentine cooling pipe 258 may be an example of a first cooling pipe having the shortest distance from the inner wall surface of the reactor.

[0110] (An example of another embodiment) In this embodiment, an example of the polymerization apparatus 100 has been described taking as an example a case where the serpentine cooling pipe is multiplexed twice from the center of the straight body portion 312 to the outside. However, the polymerization apparatus 100 is not limited to this embodiment. In other embodiments, the serpentine cooling pipe may be multiplexed three or more times from the center of the straight body portion 312 to the outside. It is preferable that the serpentine cooling pipe is multiplexed two to five times from the center of the straight body portion 312 to the outside.

[0111] 5 shows an example of the internal structure of the baffle 232. Note that the baffles 234, 236, and 238 may have the same internal structure as the baffle 232. In this embodiment, the baffle 232 has a double-tube structure including an inner tube 510 and an outer tube 520. The baffle 232 has an inlet 512 through which the refrigerant flows into the inner tube 510, and an outlet 522 through which the refrigerant flows out from the inner tube 520.

[0112] In this embodiment, the inlet 512 of the baffle 232 is connected to the refrigerant supply pipe 332 via a pipe 532 and a flow rate control valve 542. This adjusts the opening degree of the flow rate control valve 542, thereby adjusting the flow rate of the refrigerant flowing into the baffle 232. Similarly, the inlet 512 of the baffle 234 is connected to the refrigerant supply pipe 332 via a pipe 534 and a flow rate control valve 544.

[0113] In this embodiment, the outlet 522 of the baffle 232 is connected to the refrigerant return pipe 334 and the baffle 234 via a connecting portion 342. As shown in FIG 5, in this embodiment, the connecting portion 342 has a pipe 552, a flow rate control valve 554, a pipe 556, and a flow rate control valve 558.

[0114] The pipe 552 connects the outlet 522 and the refrigerant return pipe 334. The flow rate control valve 554 is disposed in the middle of the pipe 552 and adjusts the flow rate of the refrigerant flowing through the pipe 552. The pipe 556 connects the outlet 522 and the baffle 234. More specifically, the pipe 556 connects a position on the pipe 552 between the flow rate control valve 554 and the outlet 522 of the baffle 232 and a position on the pipe 534 between the flow rate control valve 544 and the inlet 512 of the baffle 234. The flow rate control valve 558 is disposed in the middle of the pipe 556 and adjusts the flow rate of the refrigerant flowing through the pipe 556.

[0115] (An example of another embodiment) In this embodiment, an example of the polymerization apparatus 100 has been described in which the baffle 232 has a double pipe structure, and the refrigerant that flows in from below the baffle 232 flows out from below the baffle 232 and flows into the baffle 234 from below the baffle 234. However, the polymerization apparatus 100 is not limited to this embodiment.

[0116] In another embodiment, the piping may be configured such that the coolant flowing in from below the baffle 232 flows out from above the baffle 232 and flows into the baffle 234 from above the baffle 234. In yet another embodiment, the baffle 232 may be a single pipe.

[0117] 6 shows a schematic example of the structure of the serpentine cooling pipe 252. The other serpentine cooling pipes 140 and 150 may have the same structure as the serpentine cooling pipe 252. As shown in FIG. 6, the serpentine cooling pipe 252 extends in the z direction while repeatedly bending. In this embodiment, the serpentine cooling pipe 252 has a serpentine portion 610. The serpentine portion 610 has a plurality of extension portions 612 and one or more bent portions 614.

[0118] In the serpentine cooling tube 252 described in relation to Fig. 6, the serpentine portion 610 has 15 extensions 612 and 14 bends 614. The number of extensions 612 in a single serpentine portion 610 may be referred to as the number of stages. As shown in Fig. 2, in this embodiment, the serpentine cooling tube 252 extends in the xy plane at the extensions 612 and bends in the z direction at the bends 614.

[0119] In this embodiment, each of the multiple extension parts 612 extends on approximately the same plane. For example, even if the extension parts 612 are designed to extend on the same plane, the extension parts 612 may not extend completely on the same plane due to manufacturing errors, installation errors, and the like. In such a case, the extension parts 612 may be considered to extend on approximately the same plane. Note that the case where the extension parts 612 extend on approximately the same plane is not limited to the above example.

[0120] In this respect, the serpentine cooling pipe 252 differs from a spiral cooling pipe. Since the serpentine cooling pipe 252 extends in a serpentine manner, the surface area per installation area can be increased compared to a cooling pipe extending in a spiral manner.

[0121] As described in relation to FIG. 4, in this embodiment, each of the multiple extension portions 612 extends while curving on the xy plane. The length PL in the extension direction of each of the multiple extension portions 612 may be the same, or the lengths in the extension direction of at least two of the extension portions 612 may be different. In this embodiment, PL is the length of the extension portion 612 on the xy plane. PL may be the length of the extension portion 612 in the xy plane passing through the center of the cross section of the extension portion 612 when the extension portion 612 is cut along a plane approximately perpendicular to the extension direction of the extension portion 612 (in this case, a plane approximately parallel to the z direction).

[0122] As described above, PL may be smaller than ⅔ of the inner circumferential length of the body portion 312. In this respect, the serpentine cooling pipe 252 differs from the coiled cooling pipe described in JP-A-7-233206.

[0123] In a single serpentine portion 610, the PL of more than 1 / 2 of the multiple extension portions 612 may be smaller than 2 / 3 of the inner peripheral length of the straight body portion 312. The above PL may be 1 / 2 or less of the inner peripheral length of the straight body portion 312, may be smaller than 1 / 2 of the inner peripheral length of the straight body portion 312, may be smaller than 1 / 3 of the inner peripheral length of the straight body portion 312, may be smaller than 1 / 3 of the inner peripheral length of the straight body portion 312, may be 1 / 4 or less of the inner peripheral length of the straight body portion 312, may be smaller than 1 / 4 of the inner peripheral length of the straight body portion 312, may be 1 / 6 or less of the inner peripheral length of the straight body portion 312, or may be smaller than 1 / 6 of the inner peripheral length of the straight body portion 312.

[0124] Among the multiple extension portions 612, the PL of more than 2 / 3 of the extension portions 612 may be smaller than 2 / 3 of the inner peripheral length of the straight body portion 312. The above PL may be 1 / 2 or less of the inner peripheral length of the straight body portion 312, may be smaller than 1 / 2 of the inner peripheral length of the straight body portion 312, may be smaller than 1 / 3 of the inner peripheral length of the straight body portion 312, may be smaller than 1 / 3 of the inner peripheral length of the straight body portion 312, may be 1 / 4 or less of the inner peripheral length of the straight body portion 312, may be smaller than 1 / 4 of the inner peripheral length of the straight body portion 312, may be 1 / 6 or less of the inner peripheral length of the straight body portion 312, or may be smaller than 1 / 6 of the inner peripheral length of the straight body portion 312.

[0125] In one embodiment, at least one of the multiple extension portions 612 extends in a curved manner on approximately the same plane. For example, at least one of the multiple extension portions 612 extends along a circular or elliptical arc virtually disposed on the xy plane. In another embodiment, at least one of the multiple extension portions 612 extends linearly on approximately the same plane.

[0126] In this embodiment, two of the multiple extension portions 612 extend on two substantially parallel planes. For example, two adjacent extension portions 612 extend on two substantially parallel planes. This results in a meandering portion 610 that extends in a ladder shape. In another embodiment, two of the multiple extension portions 612 may extend on two non-parallel planes. For example, two adjacent extension portions 612 extend on two intersecting planes. This results in a meandering portion 610 that extends in a zigzag shape.

[0127] In this embodiment, each of the one or more bent portions 614 connects the ends of two adjacent extension portions 612. In the embodiment shown in FIG. 6, each of the one or more bent portions 614 includes a portion bent in the z direction. As a result, the serpentine portion 610 extends in the z direction while bending. The shape of the bent portion 614 is not particularly limited. The shape of a cross section (sometimes referred to as a longitudinal section) of the bent portion 614 cut along a plane parallel to the extension direction of the serpentine cooling pipe 252 and passing through the center of the bent portion 614 may have a continuously bent shape or a shape composed of a plurality of straight lines. Examples of the continuously bent shape include a circular arc shape or an elliptical arc shape. The bent portion 614 may be composed of a portion having a continuously bent shape and a portion having a shape composed of one or more straight lines.

[0128] The diameter of the flow path of the serpentine cooling pipe 252 is not particularly limited, but the above diameter is preferably 10 to 200 mm. The number of extensions 612 (sometimes referred to as the number of stages) included in a single serpentine cooling pipe 252 is not particularly limited, but the above number of stages is preferably 2 to 70. The size of the distance (sometimes referred to as the pitch) Pp between two adjacent extensions 612 is not particularly limited, but the above Pp is preferably 60 mm or more. If Pp is less than 60 mm, polymer scale may easily adhere.

[0129] (An example of another embodiment)

[0130] In the present embodiment, an example of the serpentine cooling pipe 252 has been described, taking as an example the case where the serpentine cooling pipe 252 extends in the z direction while bending. However, the serpentine cooling pipe 252 is not limited to the present embodiment. In other embodiments, the serpentine cooling pipe 252 may extend in the x direction or the y direction while bending.

[0131] In the present embodiment, an example of the serpentine cooling pipe 252 has been described, taking as an example a case where the extension portion 612 extends on the xy plane and the bent portion 614 is bent in the z direction. However, the serpentine cooling pipe 252 is not limited to this embodiment. In other embodiments, the bent portion 614 may have a first bent member that is bent on the xy plane and a second bent member that is bent in the z direction.

[0132] 7 shows another example of the structure of the serpentine cooling pipe 252. In this embodiment, the serpentine cooling pipe 252 extends in the z-direction while bending in a zigzag shape. In this embodiment, the serpentine cooling pipe 252 includes a supply pipe 702, an outlet pipe 704, and a serpentine portion 710. In this embodiment, the serpentine portion 710 includes a plurality of extension portions 712 and one or more bend portions 714.

[0133] The supply pipe 702 distributes the refrigerant supplied to the serpentine portion 710. The outlet pipe 704 distributes the refrigerant discharged from the serpentine portion 710. The serpentine portion 710 extends in the z direction while repeatedly bending.

[0134] The serpentine cooling pipe 252 described with reference to Fig. 7 differs from the serpentine cooling pipe 252 described with reference to Fig. 6 in that the multiple extensions 712 are not arranged substantially parallel to each other. Regarding characteristics other than the above differences, the serpentine cooling pipe 252 described with reference to Fig. 7 may have a similar configuration to the serpentine cooling pipe 252 described with reference to Fig. 6.

[0135] 8 is a schematic diagram showing another example of the structure of the serpentine cooling pipe 252. In this embodiment, the serpentine cooling pipe 252 includes a supply pipe 702, an outlet pipe 704, and a serpentine portion 810. In this embodiment, the serpentine portion 810 includes a serpentine portion 812, a connecting portion 822, a serpentine portion 814, a connecting portion 824, and a serpentine portion 816.

[0136] In this embodiment, the serpentine portion 810 extends in the z direction while repeatedly bending. In this embodiment, the serpentine portion 812 extends in the x direction while repeatedly bending. The serpentine portion 812 extends, for example, in the positive direction of the x direction. In this embodiment, the connecting portion 822 connects the serpentine portion 812 and the serpentine portion 814. In this embodiment, the serpentine portion 814 extends in the x direction while repeatedly bending. The serpentine portion 814 extends, for example, in the negative direction of the x direction. In this embodiment, the connecting portion 824 connects the serpentine portion 814 and the serpentine portion 816. In this embodiment, the serpentine portion 816 extends in the x direction while repeatedly bending. The serpentine portion 814 extends, for example, in the positive direction of the x direction.

[0137] Each of the serpentine portion 812, the serpentine portion 814, and the serpentine portion 816 may have a configuration similar to that of the serpentine portion 610. For example, at least one of the serpentine portion 812, the serpentine portion 814, and the serpentine portion 816 has a plurality of extension portions and one or more bent portions. In this case, each of the plurality of extension portions may extend on the xy plane, may extend on the xz plane, or may extend on the yz plane.

[0138] 9 is a schematic diagram of an example of a main part of a polymerization apparatus 900. The polymerization apparatus 900 differs from the polymerization apparatus 100 in that the pitch Pp of the serpentine cooling pipe 140 is different from the pitch Pp of the serpentine cooling pipe 150. Regarding characteristics other than the above differences, the polymerization apparatus 900 may have the same configuration as the polymerization apparatus 100.

[0139] The pitch Pp of the serpentine cooling pipe 140 may be larger than the pitch Pp of the serpentine cooling pipe 150. For example, when the viscosity of the slurry flowing inside the reaction vessel 110 is relatively high, the flow of the slurry becomes slow. When the flow of the slurry becomes slow, scale is likely to adhere to the surfaces of the serpentine cooling pipe 140, the serpentine cooling pipe 150, the straight body portion 312, and the like. An example of a case where the viscosity of the slurry is relatively high is suspension polymerization of vinyl chloride. Even in such a case, since the serpentine cooling pipe 140 has a relatively large pitch Pp, the discharge flow generated by the stirring blade 124 reaches the serpentine cooling pipe 150 and the straight body portion 312 while retaining sufficient momentum. As a result, the flow state in the vicinity of the serpentine cooling pipe 140, the serpentine cooling pipe 150, the straight body portion 312, and the like is improved, and adhesion of scale is prevented.

[0140] (An example of another embodiment) In other embodiments, the pitch Pp of the serpentine cooling tubes 140 may be smaller than the pitch Pp of the serpentine cooling tubes 150.

[0141] 10 is a schematic diagram of an example of a main part of a polymerization apparatus 1000. The polymerization apparatus 1000 differs from the polymerization apparatus 100 in that the number of stages of the serpentine cooling pipes 140 and the number of stages of the serpentine cooling pipes 150 are different. With respect to features other than the above differences, the polymerization apparatus 1000 may have the same configuration as the polymerization apparatus 100. Furthermore, the polymerization apparatus 1000 may have features of various polymerization apparatuses according to other embodiments, to the extent that there is no technical contradiction.

[0142] In one embodiment, the number of stages of the serpentine cooling tube 140 and the serpentine cooling tube 150 is adjusted so that the position of the upper end of the serpentine cooling tube 140 is lower than the position of the upper end of the serpentine cooling tube 150. For example, when the viscosity of the slurry flowing inside the reaction vessel 110 is relatively high, scales are likely to adhere to the gas-liquid interface and foaming is likely to occur. An example of a case where the viscosity of the slurry is relatively high is suspension polymerization of vinyl chloride. When foaming at the gas-liquid interface becomes intense, heat removal by the reflux condenser 180 is limited. Even in such a case, the height of the upper end of the serpentine cooling tube 140 arranged closer to the stirring blade 124 is suppressed, so that the flow of the gas-liquid interface becomes active and adhesion and foaming of the slurry can be suppressed. It is preferable that the number of stages of the serpentine cooling tube 140 is adjusted so that the position of the upper end of the serpentine cooling tube 140 is lower than the stirring blade 124 arranged at the top stage.

[0143] (An example of another embodiment) In another embodiment, the number of stages of the serpentine cooling pipe 140 and the serpentine cooling pipe 150 may be adjusted so that the position of the lower end of the serpentine cooling pipe 140 is higher than the position of the lower end of the serpentine cooling pipe 150. In still another embodiment, the number of stages of the serpentine cooling pipe 140 is adjusted so that the serpentine cooling pipe 140 does not interfere with the rotation of the stirring blade 124.

[0144] 11 shows a schematic diagram of an example of a main part of a polymerization apparatus 1100. The polymerization apparatus 1100 differs from the polymerization apparatus 100 in that the polymerization apparatus 1100 includes a serpentine cooling pipe 1160 between the serpentine cooling pipe 140 and the serpentine cooling pipe 150. With respect to features other than the above differences, the polymerization apparatus 1100 may have the same configuration as the polymerization apparatus 100. Furthermore, the polymerization apparatus 1100 may have features of various polymerization apparatuses according to other embodiments, to the extent that there is no technical contradiction.

[0145] 12 is a schematic diagram of an example of a main part of a polymerization apparatus 1200. The polymerization apparatus 1200 differs from the polymerization apparatus 100 in that the polymerization apparatus 1200 includes a serpentine cooling pipe 1252 having a semicircular cross section, instead of the serpentine cooling pipe 252, the serpentine cooling pipe 256, and the serpentine cooling pipe 258. With respect to features other than the above differences, the polymerization apparatus 1200 may have the same configuration as the polymerization apparatus 100. Furthermore, the polymerization apparatus 1200 may have features of various polymerization apparatuses according to other embodiments, to the extent that there is no technical contradiction.

[0146] FIG. 13 is a schematic diagram of an example of a main part of the polymerization apparatus 1300. The polymerization apparatus 1300 differs from the polymerization apparatus 100 in that the polymerization apparatus 1300 includes a serpentine cooling tube 1351, a serpentine cooling tube 1352, a serpentine cooling tube 1353, a serpentine cooling tube 1354, a serpentine cooling tube 1355, and a serpentine cooling tube 1356 each including a straight extending extension portion 612, instead of the serpentine cooling tube 252, the serpentine cooling tube 254, the serpentine cooling tube 256, and the serpentine cooling tube 258 each including a curved extending extension portion 612. The polymerization apparatus 1200 also differs from the polymerization apparatus 100 in that the polymerization apparatus 1200 includes a baffle 1331, a baffle 1332, a baffle 1333, a baffle 1334, a baffle 1335, and a baffle 1336. The polymerization apparatus 1300 may have the same configuration as the polymerization apparatus 100, except for the above differences. Furthermore, within the scope not technically inconsistent, the polymerization apparatus 1300 may have the features of various polymerization apparatuses according to other embodiments.

[0147] In this embodiment, the serpentine cooling pipe 1351, the serpentine cooling pipe 1352, the serpentine cooling pipe 1353, the serpentine cooling pipe 1354, the serpentine cooling pipe 1355, and the serpentine cooling pipe 1356 are disposed on the sides of an imaginary regular hexagon at positions approximately symmetrical around the central axis of the reaction vessel 110. Also, the baffle 1331, the baffle 1332, the baffle 1333, the baffle 1334, the baffle 1335, and the baffle 1336 are disposed at the vertices of the imaginary regular hexagon.

[0148] According to this embodiment, the number of the serpentine cooling pipes 140 is different from the number of the serpentine cooling pipes 150. For example, the number of the serpentine cooling pipes 140 is smaller than the number of the serpentine cooling pipes 150. According to this embodiment, the shape of the serpentine cooling pipe 140 is not similar to the shape of the serpentine cooling pipe 150. For example, the extension portion 612 of the serpentine cooling pipe 140 extends in a curved manner, and the extension portion 612 of the serpentine cooling pipe 150 extends in a straight manner.

[0149] (An example of another embodiment) In this embodiment, an example of the polymerization apparatus 1300 has been described in which the baffle 1331, the baffle 1332, the baffle 1333, the baffle 1334, the baffle 1335, and the baffle 1336 are arranged at the vertices of an imaginary regular hexagon. However, the polymerization apparatus 1300 is not limited to this embodiment.

[0150] In another embodiment, at least one of the baffle 1331, the baffle 1332, the baffle 1333, the baffle 1334, the baffle 1335, and the baffle 1336 may be disposed between the regular hexagon and the straight body portion 312. In yet another embodiment, at least one of the baffle 1331, the baffle 1332, the baffle 1333, the baffle 1334, the baffle 1335, and the baffle 1336 may be disposed between the regular hexagon and an imaginary circle on which the serpentine cooling tube 242, the serpentine cooling tube 244, the serpentine cooling tube 246, and the serpentine cooling tube 248 are disposed.

[0151] According to the present embodiment, an example of the polymerization apparatus 1300 has been described, taking as an example a case where the number of the serpentine cooling pipes 140 is smaller than the number of the serpentine cooling pipes 150. However, the polymerization apparatus 1300 is not limited to this embodiment. In other embodiments, the number of the serpentine cooling pipes 140 may be larger than the number of the serpentine cooling pipes 150.

[0152] According to the present embodiment, an example of the polymerization apparatus 1300 has been described in which the extension portion 612 of the serpentine cooling pipe 140 extends in a curved manner and the extension portion 612 of the serpentine cooling pipe 150 extends in a straight manner. However, the polymerization apparatus 1300 is not limited to the present embodiment. In other embodiments, the extension portion 612 of the serpentine cooling pipe 140 may extend in a straight manner and the extension portion 612 of the serpentine cooling pipe 150 may extend in a curved manner.

[0153] (An example of another embodiment) In this embodiment, an example of the polymerization device 1300 has been described by taking as an example a case in which 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 device 1300 is not limited to this embodiment. In other embodiments, the diameter of the virtual circle 1403 may be smaller than the diameter of the virtual circle 1404. In still other embodiments, the diameter of the virtual circle 1403 may be larger than the diameter of the virtual circle 1405.

[0154] FIG. 14 shows an example of a main part of the polymerization apparatus 1400. The polymerization apparatus 1400 differs from the polymerization apparatus 100 in that an imaginary circle 1403 on which the baffle 232, the baffle 234, the baffle 236, and the baffle 238 are arranged is arranged between an imaginary circle 1404 on which the serpentine cooling tube 242, the serpentine cooling tube 244, the serpentine cooling tube 246, and the serpentine cooling tube 248 are arranged, and an imaginary circle 1405 on which the serpentine cooling tube 252, the serpentine cooling tube 254, the serpentine cooling tube 256, and the serpentine cooling tube 258 are arranged. With respect to the characteristics other than the above differences, the polymerization apparatus 1400 may have the same configuration as the polymerization apparatus 100. Furthermore, within a technically compatible range, the polymerization apparatus 1400 may have the characteristics of various polymerization apparatuses according to other embodiments.

[0155] FIG. 15 shows an example of a main part of the polymerization apparatus 1500. The polymerization apparatus 1500 differs from the polymerization apparatus 1400 in that the baffle 232 is disposed between the serpentine cooling pipe 242 and the serpentine cooling pipe 252, the baffle 234 is disposed between the serpentine cooling pipe 244 and the serpentine cooling pipe 254, the baffle 236 is disposed between the serpentine cooling pipe 246 and the serpentine cooling pipe 256, and the baffle 238 is disposed between the serpentine cooling pipe 248 and the serpentine cooling pipe 258. With respect to the characteristics other than the above differences, the polymerization apparatus 1500 may have the same configuration as the polymerization apparatus 1400. Furthermore, the polymerization apparatus 1500 may have the characteristics of various polymerization apparatuses according to other embodiments, as long as there is no technical contradiction.

[0156] 16 shows an example of a main part of a polymerization apparatus 1600. The polymerization apparatus 1600 differs from the polymerization apparatus 100 in that the polymerization apparatus 1600 does not include the serpentine cooling pipe 244 and the serpentine cooling pipe 248. Regarding characteristics other than the above differences, the polymerization apparatus 1600 may have the same configuration as the polymerization apparatus 100. Furthermore, within a technically compatible range, the polymerization apparatus 1600 may have the characteristics of various polymerization apparatuses according to other embodiments.

[0157] For example, when the viscosity of the slurry flowing inside the reaction vessel 110 is relatively high, if the serpentine cooling pipes 140 and 150 are arranged in multiple stages in the radial direction of the straight body portion 312, the slurry may remain in the region between the serpentine cooling pipes 140 and 150. An example of a case where the viscosity of the slurry is relatively high is suspension polymerization of vinyl chloride. Even in such a case, the number of stages in the radial direction of the serpentine cooling pipes 140 and 150 changes along the circumferential direction of the straight body portion 312, thereby suppressing the retention of the slurry. As a result, mixing of the slurry is promoted. EXAMPLES

[0158] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples.

[0159] (Polymerization apparatus and polymerization conditions) In Examples 1 to 6, 8, and 9, vinyl chloride polymers were produced using the polymerization apparatus 100 shown in FIG. 2, deionized water, vinyl chloride monomer, and commercially available reagents, while changing the size of the polymerization apparatus 100 and the structure of the serpentine cooling tube 140 and the serpentine cooling tube 150. In Examples 7 and 10, vinyl chloride polymers were produced using the polymerization apparatus 1100 shown in FIG. 11, deionized water, vinyl chloride monomer, and commercially available reagents, while changing the size of the polymerization apparatus 1100 and the structure of the serpentine cooling tube 140 and the serpentine cooling tube 150. In Comparative Example 1, vinyl chloride polymers were produced using a polymerization apparatus having a structure described in JP-A-7-233206 and commercially available reagents. Details of the specifications of the polymerization apparatus 100 or the polymerization apparatus 1100 used in Examples 1 to 10 and Comparative Example 1, respectively, are shown in Tables 1, 2, and 3.

[0160] The coolant supply temperature was the same in Examples 1 to 10 and Comparative Example 1. In each of Examples 1 to 10 and Comparative Example 1, the rotation speed of the agitator shaft 122 of the polymerization apparatus 100 or the polymerization apparatus 1100 was set based on the relationship between the rotation speed of the agitator shaft 122 and the quality in a pilot plant equipped with the same internal structure as in each example. The rotation speed of the agitator shaft 122 of the polymerization apparatus 100 or the polymerization apparatus 1100 was set so that the planned value of the agitation energy in the pilot plant and the planned value of the agitation energy in the polymerization apparatus 100 or the polymerization apparatus 1100 were approximately equal to each other.

[0161] In each of Examples 1 to 10 and Comparative Example 1, the polymerization temperature was set based on the target value of the K value of the polymer. The polymerization temperature in each of Examples 1 to 10 and Comparative Example 1 was the same as the polymerization temperature in a pilot plant equipped with the same internal structure as each example. Details of the polymerization conditions in each of Examples 1 to 10 and Comparative Example 1 are shown in Table 4, Table 5, or Table 6.

[0162] In Examples 1 to 10 and Comparative Example 1, the flow rate and temperature of the refrigerant at the inlet side of the baffle 130, the serpentine cooling tube 140, the serpentine cooling tube 150, and the jacket 170 were the same. As shown in Tables 1 to 3, in each of Examples 1 to 10 and Comparative Example 1, the polymerization test was carried out by changing the total value of the surface area of ​​the serpentine cooling tube 140 and the serpentine cooling tube 150. As a result, in each of Examples 1 to 10 and Comparative Example 1, the ratio of the amount of heat removed by the baffle 130 to the total amount of heat generated was about 12 to 17%. The ratio of the amount of heat removed by the serpentine cooling tube 140 and the serpentine cooling tube 150 to the total amount of heat generated was about 22 to 44%. The ratio of the amount of heat removed by the jacket 170 to the total amount of heat generated was about 25 to 34%. The ratio of the amount of heat removed by the reflux condenser 180 to the total amount of heat generated was about 19 to 27%.

[0163] (evaluation) In each of Examples 1 to 10 and Comparative Example 1, the time from the start of polymerization to the end of polymerization (i.e., polymerization time) was measured. In addition, in each of Examples 1 to 10 and Comparative Example 1, the K value of the produced vinyl chloride polymer was measured.

[0164] In each of Examples 1 to 10 and Comparative Example 1, it was judged whether the measured polymerization time was as planned. It was also judged whether the measured K value of the vinyl chloride polymer was as targeted. When the polymerization time was as planned and the targeted K value was obtained, it was judged that the polymerization apparatus had sufficient cooling capacity.

[0165] (Scale rating) Furthermore, the polymerization test was repeated in each of Examples 1 to 10 and Comparative Example 1. After a predetermined number of polymerization tests were completed, the surfaces of the serpentine cooling pipe 140 and the serpentine cooling pipe 150 were visually observed to confirm the presence or absence of scale adhesion. If no scale adhesion was confirmed, it was shown that the internal structure disposed in the reaction vessel 110 did not cause scale adhesion even when the polymerization tests were repeatedly performed.

[0166] [Table 1]

[0167] [Table 2]

[0168] [Table 3]

[0169] [Table 4]

[0170] [Table 5]

[0171] [Table 6]

[0172] Example 1 (Specifications of Polymerization Apparatus 100) The detailed specifications of the polymerization apparatus 100 used in Example 1 are shown in Table 1. In Example 1, first, 3 The reaction vessel 110 was prepared. The diameter of the straight body part 312 of the reaction vessel 110 was 3600 mm, and the height of the straight body part 312 was 6800 mm.

[0173] Four serpentine cooling pipes 140, each made of an austenitic stainless steel cylindrical pipe with an outer diameter of 90 mm, were arranged inside the reaction vessel 110. The distance between the center of each of the four serpentine cooling pipes 140 and the central axis of the reaction vessel 110 was 1360 mm. The four serpentine cooling pipes 140 were arranged symmetrically with respect to the central axis of the reaction vessel 110. The number of stages of each of the four serpentine cooling pipes 140 was 12. That is, each of the four serpentine cooling pipes 140 had 12 extensions 612. In each of the four serpentine cooling pipes 140, the distance between adjacent extensions 612 (sometimes referred to as pitch Pp) was 400 mm.

[0174] Similarly, four serpentine cooling pipes 150, each of which is a cylindrical pipe made of austenitic stainless steel and has an outer diameter of 90 mm, were installed inside the reaction vessel 110. The distance between the center of each of the four serpentine cooling pipes 150 and the central axis of the reaction vessel 110 was 1610 mm. The four serpentine cooling pipes 150 were arranged symmetrically with respect to the central axis of the reaction vessel 110. The number of stages in each of the four serpentine cooling pipes 150 was 12. The pitch Pp in each of the four serpentine cooling pipes 150 was 400 mm. In Example 1, the ratio of the total surface area of ​​the serpentine cooling pipes 140 and 150 to the internal volume of the reaction vessel 110 was 0.645 [m 2 / m 3 ] was the case.

[0175] Next, the rotation speed of the agitator shaft 122 was determined in consideration of the experimental results obtained using the pilot plant. The rotation speed of the agitator shaft 122 was determined in consideration of the experimental results obtained using the pilot plant, etc., so that the above-mentioned agitation energy was 80 to 200 kgf m / s m 3 Specifically, the rotation speed of the stirring shaft 122 was determined so that the target quality could be obtained at the polymerization temperature at which the K value of the produced polyvinyl chloride resin was 65.1. In the experiment using the pilot plant, the reduced viscosity (K value) of the polyvinyl chloride resin was measured in accordance with JIS K 7367-2.

[0176] The shape and number of the impellers 124, as well as the installation position, installation quantity, and installation interval Pi of the impellers 124 were scaled up in the same manner as the impellers 124 used in the pilot plant. The dimensions of the impellers 124 were scaled up so that the ratio of the dimensions of the impellers 124 to the dimensions of the reaction vessel 110 used in the pilot plant was constant. Similarly, the sizes and arrangements of the baffles 232, 234, 236, and 238 were determined.

[0177] (Polymerization method) Vinyl chloride polymers were synthesized according to the following procedure. The details of the reaction conditions are shown in Table 4.

[0178] First, 34,700 kg of deionized water, 10.3 kg of partially saponified polyvinyl alcohol with a saponification degree of 80.0 mol%, and 4.4 kg of hydroxypropyl methylcellulose with a methoxy substitution degree of 28.5 mass% and a hydroxypropyl substitution degree of 8.9% were made into an aqueous solution and charged into the reaction vessel 110. Next, 31,200 kg of vinyl chloride monomer was charged into the reaction vessel 110. Thereafter, while stirring the mixed solution with the stirrer 120, polymerization initiator A, polymerization initiator B, and polymerization initiator C were pumped into the reaction vessel 110.

[0179] As polymerization initiator A, an isoparaffin solution containing di-2-ethylhexyl peroxydicarbonate was used. The amount of di-2-ethylhexyl peroxydicarbonate added was 34.4 kg. As polymerization initiator B, an isoparaffin solution containing t-butyl peroxyneodecanate was used. The amount of t-butyl peroxyneodecanate added was 3.3 kg. As polymerization initiator C, an isoparaffin solution containing cumyl peroxyneodecanate was used. The amount of cumyl peroxyneodecanate added was 7.7 kg.

[0180] Next, hot water was passed through the jacket 170 to raise the temperature of the mixed solution inside the reaction vessel 110 to 57° C., thereby initiating polymerization. When the temperature of the mixed solution inside the reaction vessel 110 reached 57° C., the passage of cooling water through the baffle 130, the serpentine cooling tube 140, the serpentine cooling tube 150, and the jacket 170 was started. After that, when the polymerization conversion rate reached 20%, the reflux condenser 180 was operated.

[0181] Under the condition that the temperature of the mixed solution inside the reaction vessel 110 was maintained at 57°C, all cooling was stopped when the pressure inside the reaction vessel 110 dropped by 0.09 MPa compared to the average pressure after the start of polymerization. 18 minutes after all cooling was stopped, an aqueous dispersion of triethylene glycol bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate] (concentration: 40% by mass) sufficient to stop the polymerization reaction was poured into the reaction vessel 110. This terminated the polymerization reaction, and a vinyl chloride polymer was obtained.

[0182] In addition, in order to check the state of adhesion of scale, the above polymerization test was counted as one batch and was repeated.

[0183] In Example 1, the time from when the polymerization initiator was added until the polymerization reaction was completed was measured. In addition, after the polymerization reaction was completed, the reduced viscosity (K value) of the synthesized vinyl chloride resin was measured. The measurement results of the K value and polymerization time are shown in Table 4. In addition, after a predetermined number of polymerization tests were completed, the adhesion state of scale inside the reaction vessel 110 was visually confirmed. The confirmation results of the adhesion state of scale are shown in Table 4.

[0184] (Examples 2 to 4) A vinyl chloride polymer was synthesized by the same procedure as in Example 1 using a polymerization apparatus 100 having the specifications shown in Table 1. In Examples 2 to 4, the target K value was 65.1. Details of the reaction conditions in each Example are shown in Table 4. Table 4 also shows the measurement results of the K value and polymerization time, and the confirmation results of the state of scale adhesion.

[0185] (Examples 5 to 8) A vinyl chloride polymer was synthesized by the same procedure as in Example 1 using a polymerization apparatus 100 or a polymerization apparatus 1100 having the specifications shown in Table 2. In Examples 5 to 7, the target K value was 65.1. In Example 8, the target K value was 58.6. Details of the reaction conditions in each Example are shown in Table 5. In addition, the measurement results of the K value and polymerization time, and the confirmation results of the adhesion state of scale are shown in Table 5.

[0186] (Examples 9 to 10) A vinyl chloride polymer was synthesized by the same procedure as in Example 1 using a polymerization apparatus 100 or a polymerization apparatus 1100 having the specifications shown in Table 3. In Examples 9 and 10, the target K value was 65.1. Details of the reaction conditions in each Example are shown in Table 6. In addition, Table 6 shows the measurement results of the K value and polymerization time, and the confirmation results of the state of scale adhesion.

[0187] Comparative Example 1 Using the polymerization apparatus shown in Patent Document 2, a vinyl chloride polymer was synthesized in the same procedure as in Example 1. In Comparative Example 1, the target value of the K value was 65.1.

[0188] In the polymerization apparatus of Comparative Example 1, a coiled cooling pipe was used instead of the serpentine cooling pipe 140. A cylindrical pipe made of austenitic stainless steel with an outer diameter of 60 mm was used as the cooling pipe. The distance between the center of the coiled cooling pipe and the center of the reaction vessel 110 was 1100 mm. The number of coil stages was 12, and the coil pitch was 400 mm.

[0189] Similarly, a coiled cooling pipe was used instead of the serpentine cooling pipe 150. A cylindrical pipe made of austenitic stainless steel with an outer diameter of 60 mm was used as the cooling pipe. The distance between the center of the coiled cooling pipe and the center of the reaction vessel 110 was 1350 mm. The number of coil stages was 12, and the coil pitch was 400 mm.

[0190] Details of the reaction conditions in the comparative examples are shown in Table 6. Table 6 also shows the measurement results of the K value and polymerization time, and the confirmation results of the state of scale adhesion.

[0191] As shown in Tables 4 to 6, in Examples 1 to 7 and 9 to 10, a vinyl chloride polymer having a K value of 65.1 was obtained. The polymerization time was 2 to 3 hours, which was similar to the planned value. In Example 8, a vinyl chloride polymer having a K value of 58.6 was obtained. The polymerization time was 150 minutes, which was similar to the planned value. In Examples 1 to 10, no adhesion of scale was observed even after the polymerization test was repeatedly performed. Each Example shows that the polymerization apparatus has sufficient cooling capacity. Each Example shows that it is possible to simultaneously increase the size of the reaction vessel and shorten the polymerization time.

[0192] In Comparative Example 1, a vinyl chloride polymer having a K value of 65.1 was obtained. The polymerization time was 2 hours and 10 minutes, which was approximately the same as the planned value. Even when the polymerization apparatus of Comparative Example 1 was used, 3 With a volume of about 1000 ml, vinyl chloride polymer with the desired K value could be synthesized in a relatively short time. However, after the polymerization test was repeated, the adhesion of scale was confirmed, although very slight.

[0193] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is clear to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the description of the claims that such modifications and improvements can also be included in the technical scope of the present invention.

[0194] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before" or "prior to," and that the process may be performed in any order unless the output of a previous process is used in a later process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," and the like for convenience, this does not mean that the process must be performed in this order. The following describes examples of embodiments of the present invention as items. [Item 1] A reactor having a cylindrical shape; A plurality of first cooling pipes arranged inside the reactor for circulating a coolant; Equipped with Each of the plurality of first cooling pipes has a meandering portion that extends while repeatedly bending, The meandering portion is A plurality of extension portions extending linearly or curvedly; a plurality of bent portions connecting ends of two adjacent extension portions among the plurality of extension portions; Including, At least two of the plurality of first cooling pipes have different distances from an inner wall surface of the reactor, Among the at least two first cooling pipes, the length of at least a part of the plurality of extension parts included in the first cooling pipe that is the shortest distance from the inner wall surface of the reactor is shorter than 2 / 3 of the circumferential length of the inner wall surface. Reactor. [Item 2] Among the plurality of extensions included in the first cooling pipe having the shortest distance from the inner wall surface of the reactor, the length of more than 1 / 2 of the extensions is shorter than 2 / 3 of the periphery of the inner wall surface. Item 1. The reaction apparatus according to item 1. [Item 3] The ratio of the surface area of ​​the meandering portion to the internal volume of the reactor is 0.1 to 0.9 [m 2 / m 3 ], Item 1. The reaction apparatus according to item 1. [Item 4] The ratio of the surface area of ​​the meandering portion to the internal volume of the reactor is 0.5 to 0.7 [m 2 / m 3 ], Item 3. The reaction apparatus according to item 3. [Item 5] The reactor capacity is 40 to 300 m 3 That is, Item 1. The reaction apparatus according to item 1. [Item 6] Further comprising a plurality of baffles extending generally parallel to the extension direction of the reactor; Each of the plurality of baffles is disposed so that at least a portion of the baffle is in contact with the inner wall surface of the reactor, A portion of the plurality of first cooling pipes is disposed at a position between two baffles included in the plurality of baffles and away from the inner wall surface of the reactor. Item 1. The reaction apparatus according to item 1. [Item 7] At least one of the plurality of baffles has a second cooling pipe for passing a coolant therethrough. Item 7. The reaction apparatus according to item 6. [Item 8] Further comprising a reflux condenser and a jacket; Each of the reflux condenser and the jacket has a third cooling pipe for circulating a refrigerant. Item 1. The reaction apparatus according to item 1. [Item 9] The reactor is used for suspension polymerization applications. Item 1. The reaction apparatus according to item 1. [Item 10] A step of polymerizing a vinyl monomer using the reactor according to any one of items 1 to 8 to produce a vinyl polymer; The method for producing a vinyl polymer comprising the steps of: [Explanation of symbols]

[0195] 100 Polymerization apparatus, 110 Reaction vessel, 120 Agitator, 122 Agitation shaft, 124 Agitation blade, 126 Power mechanism, 130 Baffle, 132 Body, 134 Support, 140 Serpentine cooling tube, 150 Serpentine cooling tube, 170 Jacket, 172 Flow path, 180 Reflux condenser, 182 Flow path, 232 Baffle, 234 Baffle, 236 Baffle, 238 Baffle, 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 portion, 314 First head plate, 316 Second head plate, 318 Base, 332 Refrigerant supply pipe, 334 Refrigerant return pipe, 342 Connection part, 344 Connection part, 346 Connection part, 510 Inner pipe, 512 Inlet, 520 Outer pipe, 522 Outlet, 532 Pipe, 534 Pipe, 542 Flow rate control valve, 544 Flow rate control valve, 552 Pipe, 554 Flow rate control valve, 556 Pipe, 558 Flow rate control valve, 610 Serpentine part, 612 Extension part, 614 Bend part, 702 Supply pipe, 704 Outlet pipe, 710 Serpentine part, 712 Extension part, 714 Bend part, 810 Serpentine part, 812 Serpentine part, 814 Serpentine part, 816 Serpentine part, 822 Connection part, 824 Connection part, 900 Polymerization device, 1000 Polymerization device, 1100 Polymerization apparatus, 1160 serpentine cooling tube, 1200 polymerization apparatus, 1252 serpentine cooling tube, 1300 polymerization apparatus, 1331 baffle, 1332 baffle, 1333 baffle, 1334 baffle, 1335 baffle, 1336 baffle, 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 virtual circle, 1404 virtual circle, 1405 virtual circle, 1500 polymerization apparatus, 1600 polymerization apparatus

Claims

1. A reactor having a cylindrical shape; A plurality of first cooling pipes arranged inside the reactor for circulating a coolant; A stirrer having a stirring shaft and a stirring blade; Equipped with Each of the plurality of first cooling pipes has a meandering portion that extends while repeatedly bending, The meandering portion is A plurality of extension portions extending linearly or curvedly; a plurality of bent portions connecting end portions of two adjacent extension portions among the plurality of extension portions; Including, At least two of the plurality of first cooling pipes have different distances from an inner wall surface of the reactor, a length of at least a part of the plurality of extension portions included in a first cooling pipe that is the shortest distance from an inner wall surface of the reactor among the at least two first cooling pipes is shorter than 2 / 3 of a circumferential length of the inner wall surface; The stirring blades are installed in multiple stages. Reactor.

2. A reactor having a cylindrical shape; A plurality of first cooling pipes arranged inside the reactor for circulating a coolant; A stirrer having a stirring shaft and a stirring blade; Equipped with Each of the plurality of first cooling pipes has a meandering portion that extends while repeatedly bending, The meandering portion is A plurality of extension portions extending linearly or curvedly; a plurality of bent portions connecting end portions of two adjacent extension portions among the plurality of extension portions; Including, At least two of the plurality of first cooling pipes have different distances from an inner wall surface of the reactor, a length of at least a part of the plurality of extension portions included in a first cooling pipe that is the shortest distance from an inner wall surface of the reactor among the at least two first cooling pipes is shorter than 2 / 3 of a circumferential length of the inner wall surface; The shape of the stirring blade is a Pfaudle blade, a blue margin blade, a paddle blade, an inclined paddle blade, a turbine blade, a propeller blade, or a combination thereof. Reactor.

3. A reactor having a cylindrical shape; A plurality of first cooling pipes arranged inside the reactor for circulating a coolant; An even number of baffles; Equipped with Each of the plurality of first cooling pipes has a meandering portion that extends while repeatedly bending, The meandering portion is A plurality of extension portions extending linearly or curvedly; a plurality of bent portions connecting end portions of two adjacent extension portions among the plurality of extension portions; Including, At least two of the plurality of first cooling pipes have different distances from an inner wall surface of the reactor, a length of at least a part of the plurality of extension portions included in a first cooling pipe that is the shortest distance from an inner wall surface of the reactor among the at least two first cooling pipes is shorter than 2 / 3 of a circumferential length of the inner wall surface; The even number of baffles are generally symmetrically disposed about the elongated axis of the reactor. Reactor.

4. A reactor having a cylindrical shape; A plurality of first cooling pipes arranged inside the reactor for circulating a coolant; one or more baffles; Equipped with Each of the plurality of first cooling pipes has a meandering portion that extends while repeatedly bending, The meandering portion is A plurality of extension portions extending linearly or curvedly; a plurality of bent portions connecting end portions of two adjacent extension portions among the plurality of extension portions; Including, At least two of the plurality of first cooling pipes have different distances from an inner wall surface of the reactor, a length of at least a part of the plurality of extension portions included in a first cooling pipe that is the shortest distance from an inner wall surface of the reactor among the at least two first cooling pipes is shorter than 2 / 3 of a circumferential length of the inner wall surface; The baffle has a plate-like or cylindrical shape extending approximately parallel to the extension direction of the reactor. Reactor.

5. Among the plurality of extensions included in the first cooling pipe having the shortest distance from the inner wall surface of the reactor, the length of more than 1 / 2 of the extensions is shorter than 2 / 3 of the periphery of the inner wall surface. A reactor according to any one of claims 1 to 4.

6. The ratio of the surface area of ​​the meandering portion to the internal volume of the reactor is 0.1 to 0.9 [m ２ / m ３ ], A reactor according to any one of claims 1 to 4.

7. The ratio of the surface area of ​​the meandering portion to the internal volume of the reactor is 0.5 to 0.7 [m ２ / m ３ ], The reactor of claim 6.

8. The internal volume of the reactor is 40 to 300 m ３ That is, A reactor according to any one of claims 1 to 4.

9. Further comprising a plurality of baffles extending generally parallel to the extension direction of the reactor; Each of the plurality of baffles is disposed so that at least a portion of the baffle is in contact with the inner wall surface of the reactor, A portion of the plurality of first cooling pipes is disposed at a position between two baffles included in the plurality of baffles and at a position away from the inner wall surface of the reactor.

3. The reactor according to claim 1 or 2.

10. At least one of the plurality of baffles has a second cooling pipe for passing a coolant therethrough.

10. The reactor of claim 9.

11. At least one of the baffles has a second cooling line for passing a coolant therethrough.

5. The reactor according to claim 3 or 4.

12. Further comprising a reflux condenser and a jacket; Each of the reflux condenser and the jacket has a third cooling pipe for circulating a refrigerant. A reactor according to any one of claims 1 to 4.

13. The reactor is used for suspension polymerization applications. A reactor according to any one of claims 1 to 4.

14. A step of polymerizing a vinyl monomer using the reactor according to any one of claims 1 to 4 to produce a vinyl polymer; The method for producing a vinyl polymer comprising the steps of:

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