Eyebrow coil jacket, a heat control apparatus of a reactor using the eyebrow coil jacket, and a method for manufacturing the heat control apparatus

Abstract

Disclosed herein is an eyebrow coil jacket, a heat control apparatus of a reactor using the eyebrow coil jacket, and a method for manufacturing the heat control apparatus of the reactor. According to the present invention, it is possible to provide an eyebrow coil jacket that is capable of increasing the heat control area of the reactor even when applied to a large-sized reactor so that a heat control amount of the heat control apparatus is improved 20% more than when a half pipe coil is used, a heat control apparatus of a reactor using the eyebrow coil jacket, and a method for manufacturing the heat control apparatus of the reactor.

Claims

1. A reactor including a reflux condenser, an outer wall having an outer surface, and a heat control apparatus, the heat control apparatus comprises a semi-circularly shaped pipe having a radius of curvature and a chord length that is 50 to 80% of the radius, the semi-circularly shaped pipe includes first and second edges along the length of the pipe, the edges defined by the ends of the semi-circular shape, wherein the semi-circularly shaped pipe is provided along the outer wall of the reactor such that the edges contact the outer surface, wherein the semi-circularly shaped pipe forms a spiral tunnel having a plurality of adjacent spirals surrounding the reactor, wherein the spiral tunnel is provided along the outer wall such that the first and second edges of the adjacent spirals are fixed to the outer wall by a single welding portion, wherein the reactor is a continuous or batch polymerization reactor for exothermic polyvinyl chloride polymerization, wherein the spiral tunnel is configured such that each contact point between the edges of the semi-circularly shaped pipe and the outer surface of the reactor defines a respective angle, wherein the angle is between a normal line of the outer surface at the respective contact point and a tangent line of the semi-circular shaped pipe at the edge at the respective contact point, wherein the angle is equal to or greater than 35 and less than 50, and wherein the chord length of the semi-circularly shaped pipe is twice or more of a thickness of the outer wall of the reactor.

2. The reactor of claim 1, wherein the semi-circularly shaped pipe is obtained by cutting a circular pipe into the semi-circular shape.

3. The reactor of claim 2, wherein the semi-circularly shaped pipe is made of carbon steel or stainless steel.

4. The reactor of claim 1, wherein the reactor is configured to circulate a coolant through the spiral tunnel to perform heat exchange.

5. A method for manufacturing the reactor of claim 1, the method comprising the steps of: placing the semi-circularly shaped pipe on the outer surface of the reactor; and welding the pipe to the outer wall.

6. The method of claim 5, wherein the welding is performed by any one of arc welding, argon welding, and oxygen welding.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a sectional view schematically showing construction of a coil jacket 1, a reactor 2, and a reflux condenser 3 according to manufacture example 1 of the present invention.

(2) FIG. 2 is a sectional view schematically showing a coil interval and a welding tangent angle upon welding of the jacket, FIG. 2(a) shows a half pipe coil type and FIG. 2(b) shows an eyebrow coil type.

(3) FIG. 3 is a sectional view schematically showing a coil jacket provided at the outer wall of the body of the reactor 1 of FIG. 1, FIG. 3(a) shows the section of a half pipe coil jacket and FIG. 3(b) shows the section of an eyebrow coil jacket.

DESCRIPTION OF REFERENCE NUMERALS

(4) 1: Coil jacket 2: Reactor 3: Reflux condenser 4: welding rod 5: Section of eyebrow coil jacket 6: Section of half() pipe coil jacket 7: Outer wall of body of reactor 8: Jacket welded portion

Best Mode

(5) Now, preferred embodiments of the present invention will be described so as to allow those skilled in the art to easily understand the present invention through the preferred embodiments. However, the following embodiments are disclosed for illustrative purposes and, therefore, those skilled in the art will appreciate that various changes and modifications are possible without departing from the scope and spirit of the invention. In addition, it is obvious that such changes and modifications belong to the accompanying claims.

(6) Hereinafter, a method of polymerizing a vinyl chloride polymer will be proposed as a manufacture example to assist understanding of the present invention. However, a manufacturing method to embody the present invention is not limited thereto.

Manufacture Example 1

(7) A circular pipe (having an inner diameter of about 203 mm) made of carbon steel or stainless steel was cut such that the circular pipe had a length equivalent to 33.3% based on the inner diameter of the circular pipe and the circular pipe was bent using a machine as needed to form a sealed tunnel when the circular pipe was welded along the outer wall of a reactor to prepare a plurality of eyebrow type cutouts.

(8) The above eyebrow type cutouts were wound on the outer wall (having a thickness of 33 mm) of a stainless steel polymerization reactor 2, having an inner volume of 1 m.sup.3, provided with a reflux condenser 3, by any one of arc welding, argon welding, or oxygen welding, in a spiral shape such that an angle between a normal line of the reactor 2 and a tangent line of an eyebrow coil jacket 5 was 35 to provide a coil jacket 1 (see FIG. 1).

(9) Specifically, the above welding was performed through full penetration in a state in which a welding tangent angle of a welding rod 4 was 55 as shown in FIG. 2(b) such that a gap interval a between jacket welded portions 8 of the eyebrow coil jacket 5 was 13 mm and a length b of the pipe constituting the coil jacket was 177 mm as shown in FIG. 3(b) (the gap interval a between the coil jacket welded portions 8 was apart from twice or more the thickness of the body (thickness c of the outer wall)).

Manufacture Example 2

(10) A circular pipe made of the same material as the manufacture example 1 was cut such that the circular pipe had a length equivalent to 50% based on the inner diameter of the circular pipe to prepare a plurality of half pipe type cutouts.

(11) The above half pipe type cutouts were wound on the outer wall (having a thickness of 33 mm) of a stainless steel polymerization reactor 2, having an inner volume of 1 m.sup.3, provided with a reflux condenser 3, by any one of arc welding, argon welding, or oxygen welding, in a spiral shape such that an angle between a normal line of the reactor 2 and a tangent line of a half pipe coil jacket 6 was 35 to provide a coil jacket 1 (see FIG. 1).

(12) The above welding was performed through full penetration in a state in which a welding tangent angle of a welding rod 4 was 55 as shown in FIG. 2(a) such that a gap interval a between jacket welded portions 8 formed by the half pipe coil jacket 6 was 66 mm and a length b of the pipe constituting the coil jacket was 177 mm as shown in FIG. 3(a) (the gap interval a between the coil jacket welded portions 8 was apart from twice or more the thickness of the body (thickness c of the outer wall)).

Manufacture Example 3

(13) A jacket was manufactured using the same process as the manufacture example 1 except that the jacket was wound on the outer wall of a reactor 2 in a spiral shape such that an angle between a normal line of the reactor 2 and a tangent line of an eyebrow coil jacket 5 was 30 (a gap interval a between coil jacket welded portions was apart from twice or more the thickness of the body (thickness c of the outer wall)).

Manufacture Example 4

(14) A jacket was manufactured using the same process as the manufacture example 1 except that the jacket was wound on the outer wall of a reactor 2 in a spiral shape such that an angle between a normal line of the reactor 2 and a tangent line of an eyebrow coil jacket 5 was 60.

(15) In this case, a gap interval a between jacket welded portions formed by the eyebrow coil jacket 5 was 80 mm and a length b of the pipe constituting the coil jacket was 177 mm as shown in FIG. 3(a) (the gap interval a between the coil jacket welded portions was apart from twice or more the thickness of the body (thickness c of the outer wall)).

EXAMPLES

Example 1

(16) 130 weight parts of polymerization water, 0.05 weight part of polyvinyl alcohol having a degree of hydration of 88%, 0.02 weight part of polyvinyl alcohol having a degree of hydration of 72%, 0.01 weight part of polyvinyl alcohol having a degree of hydration of 55%, 0.01 weight part of hydroxypropylmethyl cellulose, 0.075 weight part of t-butylperoxy neodecanoate (BND), and 0.019 weight part of -cumylperoxyneodecanoate (CND) were added in the polymerization reactor 2 according to manufacture example 1.

(17) Subsequently, the reactor was evacuated by a vacuum pump during stirring and 100 weight parts of a vinyl chloride monomer was added into the reactor. In addition, a valve of a reflux condenser 3 was opened upon initiation of polymerization such that pressure change was not generated and a coolant was circulated into an eyebrow coil jacket 1 to perform heat exchange.

(18) Polymerization was performed in a state in which the reactor was maintained at a temperature of 57 C. and the polymerization was stopped when the pressure of the reactor was changed by 1.0 kg/cm.sup.2.

(19) Subsequently, 0.05 weight part of triethylene glycol-bis-[3-(3-t-butyl-5-methyl-4-hydroxy phenyl) propionate] was added as an antioxidant and unreacted monomer was collected to obtain resin slurry.

Example 2

(20) Resin slurry was obtained in the same manner as in example 1 except that 0.025 weight part of polyvinyl alcohol having a degree of hydration of 88%, 0.041 weight part of polyvinyl alcohol having a degree of hydration of 72%, 0.032 weight part of polyvinyl alcohol having a degree of hydration of 55%, 0.01 weight part of hydroxypropylmethyl cellulose, 0.068 weight part of t-butylperoxy neodecanoate (BND), and 0.017 weight part of -cumylperoxyneodecanoate (CND) were used and the polymerization temperature was 58 C.

Comparative Example 1

(21) Resin slurry was obtained in the same manner as in example 1 except that the reactor of manufacture example 1 was replaced by the reactor of manufacture example 2 and 0.070 weight part of t-butylperoxy neodecanoate (BND) and 0.018 weight part of -cumylperoxyneodecanoate (CND) were used.

Comparative Example 2

(22) Resin slurry was obtained in the same manner as in example 2 except that the reactor of manufacture example 1 was replaced by the reactor of manufacture example 2 and 0.064 weight part of t-butylperoxy neodecanoate (BND) and 0.016 weight part of -cumylperoxyneodecanoate (CND) were used.

Comparative Example 3

(23) Polymerization was performed in the same manner as in example 1 except that the reactor of manufacture example 1 was replaced by the reactor of manufacture example 3.

(24) However, an angle for full penetration of the reactor itself was increased so that a welding defect state of a jacket disposed in the reactor was serious. Consequently, a coolant could not be circulated in the eyebrow coil jacket 1 so that the polymerization reaction was not proceeded.

Comparative Example 4

(25) Resin slurry was obtained in the same manner as in example 1 except that the reactor of manufacture example 1 was replaced by the reactor of manufacture example 4.

(26) For reference, examples 1 and 2 were used the reactors applied the eyebrow coil jacket 5 of manufacture example 1, comparative examples 1 and 2 were used the reactors installed the half pipe coil jacket 6 of manufacture example 2, and comparative example 4 was used the reactor, in which the tangent angle of the eyebrow coil jacket 5 of manufacture example 4 vary.

(27) Physical properties of the vinyl chloride polymers manufactured according to examples 1, 2 and comparative examples 1, 2, and 4 were measured using the following method. The measurement results are shown in Table 1 below. The specific measurement method is as follows: Average particle size: was measured based on ASTM D 1243-79. Apparent specific gravity: was measured based on ASTM D1895-89. Plasticizer absorptivity: a ratio of a content of dioctyl phthalate (DOP) plasticizer absorbed to a weight of the sample before absorption was expressed in weight part based on ASTM D3367-95. Number of fish eyes: 45 weight parts of a dioctyl phthalate (DOP) plasticizer, 0.1 weight part of barium stearate, 0.2 weight part of tin-based stabilizer, and 0.1 weight part of carbon black were mixed with 100 weight part of the manufactured vinyl chloride polymer using a 6 inch roll at a temperature of 140 C. for 4 minutes to manufacture a sheet having a thickness of 0.3 mm, and then the number of white transparent particles in 100 cm.sup.2 of the sheet was measured with the naked eye. Foam level: was measured using a foam detector during polymerization. The highest level was recorded. Heat control area of reactor: the gap interval a between the jacket welded portions was calculated from the thickness c of the outer wall of the body of the reactor, and then the calculated interval between the jacket welded portions was substituted into below equation to calculate heat control ability of the coil jacket according to high-pressure gas regulation together with the length b of the pipe constituting the coil jacket.
Heat control area of reactor (%)=b/(b+a)100[Equation 1]

(28) TABLE-US-00001 TABLE 1 Ex- Ex- Com- Com- Com- Measurement ample ample parative parative parative items 1 2 example 1 example 2 example 4 Average 176 148 183 145 186 particle size (m) Apparent 0.573 0.529 0.579 0.533 0.568 specific gravity (g/cc) Plasticizer 16.7 26.5 16.5 26.1 16.9 absorptivity (wt %) Poly- 207 209 218 219 211 merization time (min) Fish eyes 18 20 (number) Foam level 6 11 8 13 22 (%) Heat control 93 93 73 73 69 area of reactor (%)

(29) As shown in the above Table 1, reaction time in examples 1 and 2 using the reactors applied the eyebrow coil jacket 5 of manufacture example 1, was decreased as compared with in comparative examples 1 and 2 using the reactors applied the half pipe coil jacket 6 of manufacture example 2.

(30) On the other hand, it can be seen that polymerization time in comparative example 4 was similar to that in example 1 due to the same initiator content; however, heat control portion of the reflux condenser was increased according to reduction in heat control portion of the reactor.

(31) In addition, quality improvement equal to or greater than in comparative examples 1 and 2 was achieved in examples 1 and 2, in which the introduction amount of the initiator was increased so that the exothermic amount was increased and thus the heat control portion of the reflux condenser 3 was decreased.

(32) As described above, the heat control portion of the reflux condenser 3 is increased, and thus the height of foam generated during polymerization is increased due to the increase in content of the vinyl chloride monomer evaporated in a liquid state during reaction. Consequently, the increase in heat control rate of the jacket can be indirectly confirmed.

(33) As the result of confirming the foam level state, it could be confirmed that in examples 1 and 2, in which the amount of the initiator was increased, had foam levels similar to those in comparative examples 1 and 2.

(34) Therefore, it was examined that the reactors having the eyebrow coil jacket 5 according to examples 1 and 2 had a higher heat control effect than the conventional reactor having the half pipe coil jacket 6.

(35) Meanwhile, it was confirmed that the foam level in comparative example 4 was higher than that in example 1. This is why the angle between the normal line of the reactor and the tangent line of the jacket is increased, and thus the gap interval between the jacket coils is increased so that the heat control area of the jacket is decreased during polymerization.

(36) Furthermore, if the heat control portion of the reflux condenser 3 is increased so that a large amount of foam is generated, scale is formed in the polymerization reactor 2. As a result, heat control efficiency is deteriorated, and thus a productivity yield may be reduced in the long term.

(37) Moreover, examples 1 and 2 using the reactor of manufacture example 1 were used 93% based on the area of the reactor as the heat control area. On the other hand, comparative examples 1 and 2 using the reactor of manufacture example 2 were used 73% based on the area of the reactor as the heat control area, and comparative example 4 using the reactor of manufacture example 4 was used 69% based on the area of the reactor as the heat control area.

(38) According to the present invention, therefore, the heat control area of the reactor may be increased by 20% or more than in the conventional art.