JP4285938B2 - Easily polymerizable substance handling equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus such as (meth) acrylic acid, an easily polymerizable substance such as (meth) acrylic acid ester and (meth) acrolein, and an apparatus such as a distillation column for producing and handling a liquid containing these easily polymerizable substances. More specifically, the present invention relates to an easily polymerizable substance handling apparatus in which the retention of easily polymerizable substances inside the apparatus and the generation and growth of polymers associated therewith are suppressed.
[0002]
[Prior art]
Easily polymerizable substances such as (meth) acrylic acid, (meth) acrylic acid ester, and (meth) acrolein are very easy to polymerize, and when they are manufactured and handled, these polymers are generated, In some cases, devices and processes are often stopped.
[0003]
As a countermeasure, (i) adding a polymerization inhibitor such as hydroquinone or phenothiazine in the production of (meth) acrylic acid, (meth) acrylic acid ester and (meth) acrolein, and (ii) In order to prevent solids such as polymers and precipitates from adhering to the inside of the device, surface polishing treatment is performed inside the device, (iii) cooling from the outer surface of the device (in some cases heating), (iv) It is known to prevent liquid stay and retention. However, it has not yet been achieved to completely prevent generation and adhesion of solid contents such as polymerized substances and precipitates.
[0004]
When synthesizing and purifying (meth) acrylic acid, (meth) acrylic acid ester, (meth) acrolein and the like, a distillation process is necessary. The problem in the distillation process is polymerization due to retention of easily polymerizable substances in the distillation column and the concave portions formed in the tank, heat exchanger, apparatus, equipment, etc. associated therewith. Generation of solids and solids.
[0005]
Examples of such recesses include open inspection ports for internal inspection of distillation towers, tanks, devices, and equipment, and attachment ports for measuring instruments such as pressure transmitters for measuring internal pressure and liquid level.
FIG. 4 is an upper cross-sectional view showing an example of an open inspection port in a conventional distillation tower. The open inspection port 11 includes a tubular member 14 joined to the periphery of the opening 13 on the side wall of the distillation column main body 12 with one end opened in the distillation column main body 12, and a lid for sealing the other end of the tubular member 14. The flange 15 and the lid 15 of the tubular member 14 are fastened by a combination of bolts 16 and nuts 17.
[0006]
[Problems to be solved by the invention]
In the open inspection port 11, the gas of the easily polymerizable substance flowing from the inside of the distillation column main body 12 is cooled and condensed in the tubular member 14 protruding outside from the distillation column main body 12, and the easily polymerizable substance is condensed. There was a problem that the liquid stayed and polymerization of the easily polymerizable substance occurred. Further, the concentration of the polymerization inhibitor in the gas of the easily polymerizable substance was extremely low, and the polymerization of the easily polymerizable substance was likely to occur in the condensate in which the gas was condensed.
[0007]
Also, once the polymer or the like is generated, the retention of the agglomerated liquid is promoted, and the polymer starts to grow locally and rapidly around that part. Abnormality occurred, and as a result, the entire process equipment including the distillation tower could be disabled.
[0008]
Furthermore, when the type of the easily polymerizable substance to be handled is changed due to the change of the production type, the easily polymerizable substance of the previous variety staying in the recess in the easily polymerizable handling device is mixed into the next variety, In some cases, quality abnormalities were exceeded.
Accordingly, an object of the present invention is to provide an easily polymerizable substance handling apparatus in which the retention of easily polymerizable substances inside the apparatus, and the generation and growth of polymers associated therewith are suppressed.
[0009]
[Means for Solving the Problems]
That is, the easily polymerizable substance handling apparatus of the present invention comprises an easily polymerizable substance comprising a tubular member having one end opened in the apparatus and joined to the side wall of the apparatus body, and the other end sealed with a lid. In the apparatus to be handled, the entire circumference of the inner wall surface of the tubular member is a tapered surface having a large diameter toward the apparatus main body, and the gradient of the tapered surface is in the range of 3 to 70 ° with respect to the central axis of the tubular member. It is characterized by that.
[0010]
Moreover, in the easily polymerizable substance handling apparatus of this invention, it is desirable that the length of the tubular member from the side wall of the apparatus main body to the lid is 1/3 or less of the diameter of the lid.
In addition, the lid body has an end face of the tubular member inserted by inserting a male screw fixed to the female screw hole on the end face of the tubular member into the through hole on the peripheral edge of the lid body and attaching a nut to the male screw protruding from the lid body. It is desirable to be fixed to.
[0011]
Moreover, it is desirable that the easily polymerizable substance is one selected from the group consisting of (meth) acrylic acid, (meth) acrylic acid ester, and (meth) acrolein.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The easily polymerizable substance handling apparatus in the present invention is an apparatus for producing an easily polymerizable substance or an apparatus for handling an easily polymerizable substance. Examples of such an easily polymerizable material handling apparatus include a distillation column, an associated heat exchanger, a storage tank, etc .; a reactor used for the synthesis of an easily polymerizable material, an associated heat exchanger, Examples include storage tanks.
[0013]
In addition, the easily polymerizable substance in the present invention is not particularly limited as long as it is a substance that is easily polymerized, and examples thereof include a polymerizable vinyl compound. Examples of the polymerizable vinyl compound include unsaturated carboxylic acids such as (meth) acrylic acid, methyl (meth) acrylate, normal butyl (meth) acrylate, isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, 2- Alkyl (meth) acrylates such as ethylhexyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, Alicyclic, aromatic, heterocyclic and vinyl group-containing (meth) acrylates such as glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and allyl (meth) acrylate, hydroxy Hydroxyl or alkoxyl group-containing (meth) acrylates such as til (meth) acrylate, hydroxypropyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, ethylene glycol di (meth) acrylate , Triethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate (Meth) acrylates such as polyfunctional (meth) acrylates such as 2- (meth) acryloyloxyethyl phthalate and 2- (meth) acryloyloxyethyl hexahydrophthalate Dialkylaminoethyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate methyl chloride salt, dimethylaminoethyl (meth) acrylate benzyl chloride salt, diethylaminoethyl (meth) acrylate, trifluoro Examples include halogenated alkyl (meth) acrylates such as ethyl (meth) acrylate and heptadecafluorodecyl (meth) acrylate, and unsaturated aldehydes such as (meth) acrolein. The easily polymerizable substance may be a single substance or a mixture of a plurality of compounds.
[0014]
Here, (meth) acrylic acid means acrylic acid or methacrylic acid, (meth) acrylate means acrylate or methacrylate, and (meth) acrolein means acrolein or methacrolein. Means that.
[0015]
The easily polymerizable substance in the present invention includes a liquid containing the above easily polymerizable substance. The liquid containing an easily polymerizable substance is, for example, a mixture of the above easily polymerizable substance and a by-product during the synthesis or generation of the easily polymerizable substance. In some cases, the third component solvent is a liquid in which a non-reactive solvent such as water, toluene, hexane or the like is mixed with a non-reactive solvent.
[0016]
Hereinafter, taking the distillation column as an example, the easily polymerizable substance handling apparatus of the present invention will be described in detail. FIG. 1 and FIG. 2 are an upper cross-sectional view and a side cross-sectional view showing an example of an open inspection port in a distillation tower which is an easily polymerizable substance handling apparatus of the present invention. The open inspection port 31 includes a tubular member 32 joined to the periphery of the opening 13 on the side wall of the distillation column main body 12 with one end opened in the distillation column main body 12, and a lid for sealing the other end of the tubular member 32. The body 15 is generally configured.
[0017]
As shown in FIG. 3, the tubular member 32 has a tapered surface 33 whose inner wall surface has a large diameter toward the apparatus main body, and one end is a joint 34 that is joined to the distillation column main body 12 by arc welding or the like, The other end is an attachment surface 35 to which the lid 15 is attached via a seal member (not shown), and a plurality of external screws 37 fixed to the plurality of female screw holes 36 by screwing. Is protruding.
[0018]
Then, the lid 15 inserts the male screw 37 of the attachment surface 35 of the tubular member 32 into a through hole (not shown) on the periphery of the lid 15 and attaches the nut 17 to the male screw 37 protruding from the lid 15. Thus, it is fixed to the attachment surface 35 of the tubular member 14 via a seal member.
The number of male threads 37 (that is, nut tightening points of the lid 15) of the tubular member 32 is not particularly limited, depending on the mass of the lid 15, the sealing property of the open inspection port 31, the pressure inside the distillation column main body 12, and the like. Is set as appropriate. As the seal member, a molded packing mainly composed of polytetrafluoroethylene, a polytetrafluoroethylene wrapped packing, or the like is preferably used.
[0019]
In this distillation column, the gradient α of the tapered surface 33 of the tubular member 32 is in the range of 3 to 70 ° with respect to the central axis 38 of the tubular member 32. When the gradient α of the tapered surface 33 is less than 3 °, the condensed liquid of the easily polymerizable substance is difficult to flow into the distillation column main body 12, and the easily polymerizable substance is likely to stay in the open inspection port 31. On the other hand, when the gradient α of the tapered surface 33 exceeds 70 °, it is difficult to join the distillation column main body 12 and the tubular member 32.
[0020]
In this distillation column, the length A of the tubular member 32 from the side wall of the distillation column main body 12 to the lid 15 is set to 1/3 or less of the diameter B of the lid 15. If the length A of the tubular member 32 is longer than 1/3 of the diameter B of the lid 15, the surface area of the portion where the open inspection port 31 protrudes from the distillation column main body 12 increases, and the gas of the easily polymerizable substance is increased. It is easy to cool and condense. Moreover, since the length A of the tubular member 32 is long, the condensed liquid of the easily polymerizable substance is less likely to flow into the distillation column main body 12, and the easily polymerizable substance is likely to stay in the open inspection port 31.
[0021]
Further, in this distillation column, a heat insulating material or heating means is provided outside the tubular member 32 and the lid 15 of the open inspection port 31 so that the gas of the easily polymerizable substance in the open inspection port 31 does not cool. May be. By providing such a heat retaining material or heating means, the amount of the easily polymerizable substance condensed in the open inspection port 31 is reduced, and the retention of the easily polymerizable substance and the accompanying generation and growth of the polymer are further suppressed. .
[0022]
In the distillation column (easily polymerizable handling device) described above, the gradient α of the tapered surface 33 of the tubular member 32 is in the range of 3 to 70 ° with respect to the central axis 38 of the tubular member 32. The easily polymerized condensate easily flows into the distillation column main body 12, and the easily polymerizable substance does not easily stay in the open inspection port 31.
[0023]
Further, since the length A of the tubular member 32 from the side wall of the distillation column main body 12 to the lid 15 is not more than 1/3 of the diameter B of the lid 15, the open inspection port 31 protrudes from the distillation column main body 12. The surface area of the portion is small, and the gas of the easily polymerizable substance is difficult to cool and condense. Further, since the length A of the tubular member 32 is short, the condensed liquid of the easily polymerizable substance easily flows into the distillation column main body 12, and the easily polymerizable substance does not easily stay in the open inspection port 31.
Further, the lid body 15 inserts the male screw 37 of the attachment surface 35 of the tubular member 32 into the through hole at the peripheral edge of the lid body 15, and attaches the nut 17 to the male screw 37 protruding from the lid body 15. 14, the length of the tubular member 32 can be shortened as compared with the case where the flange joint as shown in FIG. 4 is adopted. For this reason, cooling condensation due to the outside air is reduced, and the easily polymerizable substance is less likely to stay in the open inspection port 31.
[0024]
In addition, the distillation tower which is an example of the easily polymerizable substance handling apparatus of this invention is not limited to what is shown in FIGS. 1-3, One end opens in an apparatus and is joined to the side wall of an apparatus main body, etc. A distillation column having a tubular member whose end is sealed with a lid and handling a liquid containing an easily polymerizable substance, and the inner wall surface of the tubular member is a tapered surface having a large diameter toward the apparatus main body, As long as the inclination of the taper surface is in the range of 3 to 70 ° with respect to the central axis of the tubular member, it may have any form. Further, (I) the length of the tubular member from the side wall of the distillation column main body to the lid is 1/3 or less of the diameter of the lid, (II) the lid is formed in the female screw hole on the end surface of the tubular member. The fixed male screw is inserted into the through-hole on the peripheral edge of the lid body, and the nut is attached to the male screw protruding from the lid body, thereby having any structure of being fixed to the end surface of the tubular member preferable.
[0025]
【Example】
EXAMPLES Hereinafter, the present invention will be further described with reference to examples. However, the present invention is not limited to these examples.
[0026]
[Example 1]
Distillation of the liquid containing methacrolein was performed using a distillation tower having three open inspection ports shown in FIG. Here, the open inspection port is a state in which one end is opened in the distillation column main body at the periphery of the opening having a diameter of 0.582 m opened in the side wall of the cylindrical distillation column main body having a height of 6.95 m and an inner diameter of 1.1 m. And is composed of a tubular member having a length of 0.17 m and an inner wall taper surface having a slope α of 15 ° and a lid having a diameter of 0.675 m for sealing the other end of the tubular member. is there.
[0027]
The liquid containing methacrolein was supplied to the distillation column at a supply rate of 10 m ³ / h, and heated and evaporated by a heat exchanger connected to the bottom of the distillation column, and methacrolein was distilled at 130 ° C. During distillation, methacrolein polymer was not generated at the open inspection port, and polymer adhesion or clogging was not generated in the heat exchanger.
[0028]
[Comparative Example 1]
Distillation of the liquid containing methacrolein was performed using a distillation tower having three open inspection ports shown in FIG. Here, the open inspection port has a length of 0.25 m joined to the peripheral edge of the opening having a diameter of 0.6 m opened on the same side wall of the distillation column as in Example 1 with one end opened in the distillation column. The tubular member is generally constituted by a tubular member having an inner diameter of 0.6 m and an inner wall surface that is not tapered, and a lid member having a diameter of 0.7 m that seals the other end of the tubular member.
Using this distillation column, methacrolein was distilled in the same manner as in Example 1. During distillation, the adhesion and clogging of the polymer in the heat exchanger due to the occurrence of the polymer of methacrolein at the open inspection port occurred twice on average per month.
[0029]
【The invention's effect】
As described above, the easily polymerizable substance handling apparatus of the present invention includes a tubular member having one end opened into the apparatus and joined to the side wall of the apparatus body, and the other end sealed with a lid. In an apparatus for handling a polymerizable substance, an inner wall surface of a tubular member is a tapered surface having a large diameter toward the apparatus main body, and a gradient of the tapered surface is in a range of 3 to 70 ° with respect to the central axis of the tubular member. Therefore, the retention of the easily polymerizable substance in the apparatus, and the generation and growth of the polymerized substance accompanying it can be suppressed.
[0030]
The easily polymerizable substance handling apparatus of the present invention comprises an easily polymerizable substance comprising a tubular member having one end opened in the apparatus and joined to the side wall of the apparatus main body, and the other end sealed with a lid. In the apparatus to be handled, the length of the tubular member from the side wall of the apparatus main body to the lid is one third or less of the diameter of the lid, so that the easily polymerizable substance stays in the apparatus, and the accompanying polymer Generation and growth are suppressed.
[0031]
The easily polymerizable substance handling apparatus of the present invention comprises an easily polymerizable substance comprising a tubular member having one end opened in the apparatus and joined to the side wall of the apparatus main body, and the other end sealed with a lid. In the apparatus to be handled, the lid member is inserted into the through-hole on the peripheral edge of the lid body through the male screw fixed to the female screw hole on the end surface of the tubular member, and the nut is attached to the male screw protruding from the lid body. Therefore, the retention of the easily polymerizable substance in the inside of the apparatus, and the generation and growth of the polymerized substance accompanying it can be suppressed.
[0032]
Even if the easily polymerizable substance is a particularly easily polymerized substance such as one selected from the group consisting of (meth) acrylic acid, (meth) acrylic acid ester, and (meth) acrolein, In particular, the generation and growth of the polymer can be suppressed.
[Brief description of the drawings]
FIG. 1 is an upper cross-sectional view showing an example of an open inspection port in a distillation column that is an easily polymerizable substance handling apparatus of the present invention.
FIG. 2 is a side sectional view showing an example of an open inspection port in a distillation column which is a readily polymerizable substance handling apparatus of the present invention.
3 is a cross-sectional side view of a main part showing a tubular member of an open inspection port in FIG. 1. FIG. 4 is an upper cross-sectional view showing an example of an open inspection port in a conventional distillation tower.
[Explanation of symbols]
12 Distillation tower body (equipment body)
15 Lid 17 Nuts 32 Tubular member 33 Tapered surface 35 Mounting surface (end surface of tubular member)
36 Female threaded hole 37 Male thread A Tubular member length B Lid diameter α Taper surface gradient

Claims (3)

In an apparatus for handling an easily polymerizable substance, comprising a tubular member having one end opened in the apparatus and joined to the side wall of the apparatus main body, and the other end sealed with a lid.
The entire circumference of the inner wall surface of the tubular member is a tapered surface having a large diameter toward the apparatus main body, and the gradient of the tapered surface is in the range of 3 to 70 ° with respect to the central axis of the tubular member. Easily polymerizable substance handling equipment.   2. The easily polymerizable substance handling apparatus according to claim 1, wherein the length of the tubular member from the side wall of the apparatus main body to the lid is 1/3 or less of the diameter of the lid.   The lid is fixed to the end face of the tubular member by inserting the male screw fixed in the female screw hole on the end face of the tubular member into the through hole on the peripheral edge of the lid body and attaching a nut to the male screw protruding from the lid body The easily polymerizable substance handling apparatus according to claim 1 or 2, wherein the easily polymerizable substance handling apparatus is provided.

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