阅读说明：本技术 用于制备苯乙烯-丙烯腈共聚物的设备 (Apparatus for preparing styrene-acrylonitrile copolymer ) 是由 李青芬 张道忠 邱泓维 于 2019-02-18 设计创作，主要内容包括：一种用于制备苯乙烯-丙烯腈共聚物的设备包含第一反应器、预热器、真空脱烃器及前冷凝器。所述前冷凝器包括前冷凝壳体及两个前冷凝隔板。所述前冷凝壳体围绕界定出前冷凝空间且具有前进气口、第一前出液口及两个第二前出液口。所述前冷凝隔板使所述前冷凝空间分隔成第一前冷凝空间部及两个第二前冷凝空间部,每一个前冷凝隔板具有至少一个前冷凝缺口。本发明设备能降低后续所回收的回收单体冷凝液中苯乙烯-丙烯腈寡聚物含量。(An apparatus for preparing styrene-acrylonitrile copolymer comprises a first reactor, a preheater, a vacuum dealkylator, and a pre-condenser. The front condenser comprises a front condensation shell and two front condensation clapboards. The front condensation shell surrounds and defines a front condensation space and is provided with a front air inlet, a first front liquid outlet and two second front liquid outlets. The front condensation partition divides the front condensation space into a first front condensation space section and two second front condensation space sections, each front condensation partition having at least one front condensation gap. The equipment can reduce the content of styrene-acrylonitrile oligomer in the subsequently recovered monomer condensate.)

1. An apparatus for preparing styrene-acrylonitrile copolymer, comprising:

the first reactor is used for accommodating a first mixture, the first mixture contains a reaction composition and generates a liquid product and a gaseous evaporant after polymerization, and the reaction composition contains a styrene monomer, an acrylonitrile monomer and a solvent;

the preheater is arranged at the downstream of the first reactor and is used for heating the liquid product to obtain a styrene-acrylonitrile copolymer and volatile mixed gas;

a vacuum dealkylator disposed downstream of the preheater and separating the styrene-acrylonitrile copolymer and the volatilized mixed gas; and

a pre-condenser disposed downstream of the vacuum de-hydrocarboner and comprising:

the front condensation shell surrounds and defines a front condensation space and is provided with a front air inlet positioned at the top of the front condensation space, a first front liquid outlet and two second front liquid outlets positioned at the bottom of the front condensation space; and

two front condensation partitions arranged in the front condensation space and spaced from each other to divide the front condensation space into a first front condensation space and two second front condensation spaces respectively located at two opposite sides of the first front condensation space, each front condensation partition having at least one front condensation gap communicating the adjacent first front condensation space and the second front condensation space and spaced from the bottom of the front condensation shell,

the front gas inlet and the first front liquid outlet are respectively adjacent to the first front condensing space part, each second front liquid outlet is adjacent to the corresponding second front condensing space part, and the volatile mixed gas can enter the first front condensing space part through the front gas inlet.

2. The apparatus for preparing styrene-acrylonitrile copolymer according to claim 1, wherein: the equipment for preparing the styrene-acrylonitrile copolymer further comprises a rear condenser arranged on the downstream of the front condenser, the rear condenser comprises a rear condensation shell and a rear condensation space defined by the rear condensation shell, the rear condensation shell is provided with two rear air inlets respectively positioned at the top of the rear condensation shell and a rear liquid outlet positioned at the bottom of the rear condensation shell, the front condensation shell is further provided with two front air outlets respectively adjacent to the corresponding second front condensation space part, and the two rear air inlets of the rear condensation shell respectively correspond to and are communicated with the two front air outlets of the front condensation shell.

3. The apparatus for preparing styrene-acrylonitrile copolymer according to claim 2, wherein: the rear condensing shell also has a rear air outlet at the top thereof.

4. The apparatus for preparing styrene-acrylonitrile copolymer according to claim 1, wherein: the first reactor includes a reaction tank accommodating the first mix and a jacket unit surrounding the reaction tank, the jacket unit having a high-temperature jacket, an intermediate-temperature jacket adjacent to the high-temperature jacket, and a low-temperature jacket opposite to the high-temperature jacket and adjacent to the intermediate-temperature jacket.

5. The apparatus for preparing styrene-acrylonitrile copolymer according to claim 4, wherein: the temperature of the high-temperature jacket is between 110 ℃ and 190 ℃, the temperature of the medium-temperature jacket is between 90 ℃ and 170 ℃, and the temperature of the low-temperature jacket is between 25 ℃ and 90 ℃.

6. The apparatus for preparing styrene-acrylonitrile copolymer according to claim 1, wherein: the equipment for preparing the styrene-acrylonitrile copolymer further comprises a first reaction condenser and a first mixer, wherein the first reaction condenser is arranged at the downstream of the first reactor and is used for condensing gaseous evaporant obtained by the first reactor to obtain evaporant condensate, and the first mixer is arranged at the upstream of the first reactor and is used for mixing the reaction composition, part of liquid product obtained by the first reactor and the evaporant condensate obtained by the first reaction condenser to obtain the first mixed material.

7. The apparatus for preparing styrene-acrylonitrile copolymer according to claim 6, wherein: the equipment for preparing the styrene-acrylonitrile copolymer further comprises a second reactor, a second reaction condenser and a second mixer, wherein the second reactor is arranged at the downstream of the first reactor and is used for accommodating a second mixed material, the second mixed material generates a liquid product and a gaseous evaporant after polymerization, the second reaction condenser is arranged at the downstream of the second reactor and is used for condensing the gaseous evaporant obtained by the second reactor to obtain an evaporant condensate, and the second mixer is arranged at the upstream of the second reactor and is used for mixing part of the liquid product obtained by the first reactor and the evaporant condensate obtained by the second reaction condenser to obtain the second mixed material.

8. The apparatus for preparing styrene-acrylonitrile copolymer according to claim 1, wherein: the temperature in the front inlet of the front condensation shell ranges from 80 ℃ to 140 ℃.

9. The apparatus for preparing styrene-acrylonitrile copolymer according to claim 2, wherein: the temperature ranges of the two front air outlets of the front condensation shell are respectively 35-60 ℃.

10. The apparatus for preparing styrene-acrylonitrile copolymer according to claim 2, wherein: the temperature ranges in the two rear inlet ports of the rear condensation shell are 35-60 ℃ respectively.

Technical Field

The present invention relates to an apparatus for preparing a copolymer, and more particularly, to an apparatus for preparing a styrene-acrylonitrile copolymer (styrene-acrylonitrile copolymer).

Background

Existing plants for the preparation of styrene-acrylonitrile copolymers generally comprise at least one reactor, a preheater and a vacuum dealkylator. Each reactor is used for polymerizing a reaction composition containing a styrene monomer, an acrylonitrile monomer and a solvent therein. The liquid product obtained after the polymerization reaction is heated in the preheater to obtain the styrene-acrylonitrile copolymer and the volatile mixed gas. Then, the styrene-acrylonitrile copolymer and the volatile mixed gas are sent to the vacuum dealkylator for separation, the styrene-acrylonitrile copolymer is pumped out from the bottom of the vacuum dealkylator for granulation, and the volatile mixed gas contains unreacted monomers, so that the volatile mixed gas is condensed into recovered monomer condensate (the components contained in the recovered monomer condensate are equivalent to the components contained in the reaction composition), and then the recovered monomer condensate is returned to the reactor for continuous reaction.

However, the recycled monomer condensate obtained by condensing the volatile mixed gas may contain styrene-acrylonitrile oligomer (oligomer) in addition to styrene monomer, acrylonitrile monomer and solvent, which results in that the subsequent product may also contain styrene-acrylonitrile oligomer in addition to styrene-acrylonitrile copolymer; in addition, since the styrene-acrylonitrile oligomer is light yellow, the chromaticity of the styrene-acrylonitrile copolymer is more seriously affected. Therefore, how to improve the above-mentioned equipment for preparing styrene-acrylonitrile copolymer to reduce the content of styrene-acrylonitrile oligomer in the recovered monomer condensate becomes a problem which must be solved at present.

Disclosure of Invention

The invention aims to provide equipment for preparing styrene-acrylonitrile copolymer. The equipment can reduce the content of styrene-acrylonitrile oligomer in the subsequently recovered monomer condensate.

The equipment for preparing the styrene-acrylonitrile copolymer comprises a first reactor, a preheater, a vacuum dealkylator and a pre-condenser.

The first reactor is used for accommodating a first mixture, the first mixture contains a reaction composition and generates a liquid product and a gaseous evaporant after polymerization, and the reaction composition contains a styrene monomer, an acrylonitrile monomer and a solvent.

The preheater is arranged at the downstream of the first reactor and is used for heating the liquid product so as to obtain the styrene-acrylonitrile copolymer and volatile mixed gas.

The vacuum dealkylator is disposed downstream of the preheater and is used to separate the styrene-acrylonitrile copolymer and the volatile mixed gas.

The front condenser is arranged at the downstream of the vacuum dealkylator and comprises a front condensation shell and two front condensation clapboards.

The front condensation shell surrounds and defines a front condensation space and is provided with a front air inlet positioned at the top of the front condensation space, a first front liquid outlet positioned at the bottom of the front condensation space and two second front liquid outlets.

The front condensation partition plates are arranged in the front condensation space at intervals, the front condensation space is divided into a first front condensation space part and two second front condensation space parts which are respectively positioned at two opposite sides of the first front condensation space part, and each front condensation partition plate is provided with at least one front condensation gap which is communicated with the adjacent first front condensation space part and the second front condensation space part and is separated from the bottom of the front condensation shell.

The front gas inlet and the first front liquid outlet are respectively adjacent to the first front condensing space part, each second front liquid outlet is adjacent to the corresponding second front condensing space part, and the volatile mixed gas can enter the first front condensing space part through the front gas inlet.

The invention has the following effects: since the apparatus of the present invention further comprises the front condenser disposed downstream of the vacuum dealkylator, and the front condensation space of the front condenser is divided into the first front condensation space part and the second front condensation space part by the front condensation partition plate, and each front condensation partition plate has a front condensation gap spaced from the bottom of the front condensation shell, the apparatus of the present invention can reduce the content of styrene-acrylonitrile oligomer in the subsequently recovered monomer condensate.

To explain the foregoing functional principle in more detail, when the apparatus of the present invention is used to prepare a styrene-acrylonitrile copolymer, styrene-acrylonitrile oligomers present in the volatilized mixed gas are condensed to form oligomer condensate when the volatilized mixed gas enters the first front condensation space, and then flow out from the first front liquid outlet. And the residual uncondensed volatile mixed gas after the removal of the styrene-acrylonitrile oligomer flows into the second front condensing space part through the front condensing gap, is condensed in the second front condensing space part to form recovered monomer condensate, and then flows out from the second front liquid outlet for recovery. In addition, the design of the front condensation partition plate (the front condensation gap is separated from the bottom of the front condensation shell) can block the oligomer condensate from flowing into the second front condensation space part, and can prevent the recovered monomer condensate in the second front condensation space part from mixing with the oligomer condensate. Therefore, as can be seen from the foregoing, when the volatilized mixed gas enters the first front condensation space portion, the styrene-acrylonitrile oligomer is removed by a condensation method, so that the content of the styrene-acrylonitrile oligomer in the volatilized mixed gas entering the second front condensation space portion is greatly reduced, and further the content of the styrene-acrylonitrile oligomer in the recovered monomer condensate is also greatly reduced, and the oligomer condensate does not exist in the recovered monomer condensate, so that the apparatus of the present invention can reduce the content of the styrene-acrylonitrile oligomer in the subsequently recovered monomer condensate.

The present invention will be described in detail below:

preferably, the apparatus for preparing styrene-acrylonitrile copolymer according to the present invention further comprises a rear condenser disposed downstream of the front condenser, the rear condenser comprising a rear condensation housing and a rear condensation space defined by the rear condensation housing, the rear condensation housing having two rear air inlets respectively located at the top thereof and a rear liquid outlet located at the bottom thereof, and the front condensation housing further having two front air outlets respectively adjacent to the corresponding second front condensation space portion, the rear air inlets of the two rear condensation housings respectively corresponding to and communicating with the front air outlets of the two front condensation housings. More preferably, the rear condensation shell further has a rear air outlet at the top thereof. More preferably, the temperature ranges in the front air outlets of the two front condensation shells are respectively 35-60 ℃. More preferably, the temperature ranges in the rear inlets of the two rear condensation shells are respectively 35-60 ℃.

Preferably, the first reactor comprises a reaction tank for accommodating the first mix and a jacket unit surrounding the reaction tank, the jacket unit having a high temperature jacket, a medium temperature jacket adjacent to the high temperature jacket, and a low temperature jacket opposite to the high temperature jacket and adjacent to the medium temperature jacket. More preferably, the temperature of the high temperature jacket is between 110 ℃ and 190 ℃, the temperature of the medium temperature jacket is between 90 ℃ and 170 ℃, and the temperature of the low temperature jacket is between 25 ℃ and 90 ℃.

Preferably, the apparatus for preparing styrene-acrylonitrile copolymer according to the present invention further comprises a first reaction condenser disposed downstream of the first reactor and used for condensing the gaseous evaporant obtained from the first reactor to obtain the evaporant condensate, and a first mixer disposed upstream of the first reactor and used for mixing the reaction composition, a part of the liquid product obtained from the first reactor, and the evaporant condensate obtained from the first reaction condenser to obtain the first mix material. Preferably, the apparatus for preparing styrene-acrylonitrile copolymer of the present invention further comprises a second reactor, a second reaction condenser and a second mixer, wherein the second reactor is disposed downstream of the first reactor and is used for accommodating a second mixture, the second mixture generates a liquid product and a gaseous evaporant after polymerization, the second reaction condenser is disposed downstream of the second reactor and is used for condensing the gaseous evaporant obtained from the second reactor to obtain an evaporant condensate, and the second mixer is disposed upstream of the second reactor and is used for mixing a part of the liquid product obtained from the first reactor and the evaporant condensate obtained from the second reaction condenser to obtain the second mixture.

Preferably, the temperature in the front air inlet of the front condensation shell ranges from 80 ℃ to 140 ℃.

Drawings

Other features and effects of the present invention will be clearly apparent from the embodiments with reference to the accompanying drawings:

FIG. 1 is a schematic view illustrating a first embodiment of an apparatus for preparing a styrene-acrylonitrile copolymer according to the present invention;

FIG. 2 is a schematic side view illustrating a first reactor of the apparatus of the first embodiment;

FIG. 3 is a schematic side view illustrating a front condenser of the apparatus of the first embodiment;

FIG. 4 is a schematic cross-sectional view taken along line IV-IV of FIG. 3, illustrating the pre-condenser of the apparatus of the first embodiment; and

fig. 5 is a schematic side view illustrating a post-condenser of the apparatus of the first embodiment.

Detailed Description

The invention will be further described in the following examples, but it should be understood that the examples are illustrative only and should not be construed as limiting the practice of the invention.

Before the present invention is described in detail, it should be noted that in the following description, similar components are denoted by the same reference numerals.

Referring to FIGS. 1 and 2, a first embodiment of the apparatus for preparing styrene-acrylonitrile copolymer according to the present invention can be used for continuously preparing styrene-acrylonitrile copolymer and can reduce the content of styrene-acrylonitrile oligomer in the recovered monomer condensate which is recovered later. The apparatus for preparing styrene-acrylonitrile copolymer of the first embodiment comprises a styrene monomer storage tank 11, an acrylonitrile monomer storage tank 12, a recovered monomer storage tank 13, a mixed monomer tank 14, a molecular weight modifier storage tank 15, a premixer 16, a first reactor 21, a first reaction condenser 22, a first condensate tank 23, a first mixer 24, a second reactor 31, a second reaction condenser 32, a second condensate tank 33, a second mixer 34, a preheater 41, a vacuum dehydroxylator 42, a pre-condenser 51, a post-condenser 61 and a recovered monomer temporary storage tank 71.

The styrene monomer storage tank 11, the acrylonitrile monomer storage tank 12, and the recovered monomer storage tank 13 are respectively disposed upstream of the mixed monomer tank 14. Styrene monomer storage tank 11 is used for storing styrene monomer, acrylonitrile monomer storage tank 12 is used for storing acrylonitrile monomer, retrieve monomer storage tank 13 and be used for storing follow-up recovery monomer condensate who retrieves.

The monomer mixture tank 14 and the molecular weight control agent tank 15 are provided upstream of the premixer 16, respectively. The molecular weight regulator storage tank 15 is used to store a molecular weight regulator such as, but not limited to, isododecyl mercaptan (tert-dodecyl mercaptan) for regulating the molecular weight of the product.

The premixer 16 is disposed upstream of the first mixer 24. The first mixer 24 is disposed upstream of the first reactor 21. The first reaction condenser 22 is disposed downstream of the first reactor 21 and upstream of the first condensate tank 23. The first condensate tank 23 is disposed upstream of the first mixer 24, so that the condensate in the first condensate tank 23 can return to the first mixer 24.

The first reactor 21 is disposed upstream of the second mixer 34 and includes a reaction tank 211 and a jacket unit 212 surrounding the reaction tank 211. The jacket unit 212 has a high-temperature jacket 2121 adjacent to the bottom of the reaction tank 211, a medium-temperature jacket 2122 adjacent to the top of the high-temperature jacket 2121, and a low-temperature jacket 2123 opposite to the high-temperature jacket 2121 and adjacent to the top of the medium-temperature jacket 2122. The temperature of the walls of the reaction tank 211 may correspond to the temperature of the high, medium and low temperature jackets 2121,2122,2123, i.e., the walls of the reaction tank 211 may exhibit a high to low temperature from the bottom to the top thereof. The high temperature, medium temperature and low temperature jackets 2121,2122,2123 are each controlled by an external heater (not shown), in this embodiment, the high temperature jacket is between 110 ℃ and 190 ℃, the medium temperature jacket is between 90 ℃ and 170 ℃, and the low temperature jacket is between 25 ℃ and 90 ℃.

The second mixer 34 is disposed upstream of the second reactor 31. The second reaction condenser 32 is disposed downstream of the second reactor 31 and upstream of the second condensate tank 33. The second condensate tank 33 is disposed upstream of the second mixer 34, so that the condensate in the second condensate tank 33 is returned to the second mixer 34.

The second reactor 31 has the same structure as the first reactor 21, that is, the second reactor 31 also includes the reaction tank and the jacket unit as described in the first reactor 21, and the jacket unit of the second reactor 31 also has the high-temperature jacket, the medium-temperature jacket, and the low-temperature jacket as described in the first reactor 21. Further, the respective temperature ranges of the high-temperature jacket, the medium-temperature jacket, and the low-temperature jacket of the second reactor 31 are also the same as the temperature ranges of the high-temperature jacket 2121, the medium-temperature jacket 2122, and the low-temperature jacket 2123, respectively, in the first reactor 21.

The preheater 41 is disposed downstream of the second reactor 31. The vacuum dealkylator 42 is disposed downstream of the preheater 41. The pre-condenser 51 is disposed downstream of the vacuum dealkylator 42. The rear condenser 61 is disposed downstream of the front condenser 51. The temporary storage tank 71 for recovered monomer is disposed downstream of the pre-condenser 51 and the post-condenser 61.

The vacuum dealkylator 42 is evacuated by a vacuum pump (not shown).

Referring to fig. 1,3 and 4, the front condenser 51 includes a front condensation shell 511 and two front condensation partitions 513. The front condensation shell 511 defines a front condensation space 512, and has a front air inlet 5111 and two front air outlets 5112 at the top thereof, and a first front liquid outlet 5113 and two second front liquid outlets 5114 at the bottom thereof. The front condensation partitions 513 are disposed in the front condensation space 512 to be spaced apart from each other, and partition the front condensation space 512 into a first front condensation space 5121 and two second front condensation spaces 5122 respectively located at opposite sides of the first front condensation space 5121. Each front condensation partition 513 has a front partition base 5131 extending upward from the bottom of the front condensation shell 511, a front partition extension 5132 extending upward from the front partition base 5131 to the top of the front condensation shell 511, and two front condensation gaps 5133, wherein the front partition base 5131, the front partition extension 5132 and the front condensation shell 511 together define the front condensation gaps 5133, and each front condensation gap 5133 communicates with one of the first front condensation space 5121 and the second front condensation space 5122 adjacent to each other and is spaced apart from the bottom of the front condensation shell 511. In an implementation, the number of the front condensation gaps 5133 may be one or more. The front air inlet 5111 and the first front liquid outlet 5113 are respectively adjacent to the first front condensation space portion 5121, and each second front liquid outlet 5114 and each front air outlet 5112 are respectively adjacent to the corresponding second front condensation space portion 5122. The front gas inlets 5111 supply gas therethrough into the first front condensation space section 5121, the front gas outlets 5112 respectively supply gas in the second front condensation space section 5122 therethrough to be discharged out of the second front condensation space section 5122, the first front liquid outlets 5113 supply liquid in the first front condensation space section 5121 therethrough to be discharged out of the first front condensation space section 5121, and the second front liquid outlets 5114 respectively supply liquid in the second front condensation space section 5122 therethrough to be discharged out of the second front condensation space section 5122.

Referring to fig. 1 and 5, the rear condenser 61 includes a rear condensation shell 611 and a rear condensation space 612 surrounded and defined by the rear condensation shell 611, the rear condensation shell 611 has two rear air inlets 6111 respectively located at the top thereof, a rear liquid outlet 6112 located at the bottom thereof and a rear air outlet 6113 located at the top thereof, and the two rear air inlets 6111 of the rear condensation shell 611 respectively correspond to and communicate with the two front air outlets 5112 (see fig. 3) of the front condensation shell 511. The rear gas inlet 6111 is used for gas to enter the rear condensation space 612, the rear liquid outlet 6112 is used for liquid in the rear condensation space 612 to be discharged out of the rear condensation space 612, and the rear gas outlet 6113 is used for gas in the rear condensation space 612 to be discharged out of the rear condensation space 612.

Referring to fig. 1, a styrene monomer, an acrylonitrile monomer, a solvent and a recycled monomer condensate obtained by subsequent recycling are respectively transferred from the styrene monomer storage tank 11, the acrylonitrile monomer storage tank 12, a solvent storage tank (not shown) and the recycled monomer storage tank 13 to the mixed monomer tank 14 to be mixed according to a specific ratio, so as to obtain a reaction composition. The specific ratio can be adjusted according to the required production specification, and in this embodiment, the weight of the styrene monomer is 45-65 wt%, the weight of the acrylonitrile monomer is 25-45 wt%, and the weight of the solvent is 10-15 wt%, based on 100 wt% of the total weight of the reaction composition. Such as, but not limited to, toluene, ethylbenzene, or combinations of the foregoing. After being metered, the molecular weight regulator in the molecular weight regulator storage tank 15 is respectively conveyed to the premixer 16 together with the reaction composition in the monomer mixing tank 14 for mixing, and then conveyed to the first mixer 24 in 100 parts by weight, and is mixed with the subsequent evaporant condensate obtained by the first reaction condenser 22 and the liquid product obtained by the first reactor 21 to obtain a first mixture.

Then, 220 parts by weight of the first mixture in the first mixer 24 is first conveyed into a reaction tank 211 (see fig. 2) of the first reactor 21 for polymerization (the reaction temperature is 120-170 ℃ and the reaction pressure is 1-5 kg/cm)²G) 200 parts by weight of liquid product and 20 parts by weight of gaseous product are producedAn evaporant. The liquid product is transferred by two gear pumps 26 to the first mixer 24 and 100 parts by weight to the second mixer 34, respectively, the gaseous evaporant is transferred to the first reaction condenser 22 for condensation to obtain 20 parts by weight of the evaporant condensate, and the evaporant condensate is transferred to the first condensate tank 23 for temporary storage, and then transferred to the first mixer 24 by a pump 25.

The liquid product from the first reactor 21 to the second mixer 34 is also mixed with the evaporate condensate from the second reaction condenser 32 to form a second mixture. 130 parts by weight of the second mixture in the second mixer 34 is firstly conveyed into a reaction tank (not shown) of the second reactor 31 for polymerization (reaction temperature is 130-170 ℃ and reaction pressure is 1-5 kg/cm)²G), 100 parts by weight of liquid product and 30 parts by weight of gaseous evaporant are produced. The liquid product is fed by means of a gear pump 36 to the preheater 41 for heating, the gaseous evaporate is fed to the second reaction condenser 32 for condensation to obtain the evaporate condensate, and the evaporate condensate is fed to the second condensate tank 33 for temporary storage and then fed by means of a pump 35 to the second mixer 34.

It should be particularly noted that, referring to fig. 1, when the first mixture and the second mixture react in the reaction tank 211 (see fig. 2) of the first reactor 21 and the reaction tank (not shown) of the second reactor 31, respectively, the unreacted monomers and the solvent are heated to evaporate (i.e. generate the gaseous evaporant). However, the gaseous evaporant tends to form gel scale on the inner wall of the reaction tank due to its increased acrylonitrile monomer content and accompanying high temperature; if the gel scale and the product are mixed, the quality of the product is affected, therefore, in the first embodiment, the outside of the reaction tank of the first reactor 21 and the second reactor 31 respectively surrounds three high-temperature jackets, medium-temperature jackets and low-temperature jackets (see fig. 2) with different temperatures, and by the design of the first embodiment, which respectively has three jackets with different temperatures, and simultaneously matches with the design of the component which is jetted from the top of the reaction tank and used for cleaning the inner wall of the reaction tank (the source of the jetted component is the premixer 16), the gaseous evaporant can not easily form gel scale on the inner wall of the reaction tank; in addition, in the first embodiment, by the design of the first mixer 24 and the second mixer 34, after the unreacted monomers and the solvent (i.e. the gaseous evaporant) evaporated by heating are condensed to form the evaporant condensate, the unreacted monomers and the solvent can be mixed with the reaction composition delivered by the pre-mixer 16 and the liquid product obtained by the reaction and adjusted to a specific ratio required by the reaction, and then delivered to the first or second reactor 21,31 for further reaction, without affecting the quality of the product to be subsequently produced because the ratio of the unreacted monomers and the solvent in the evaporant condensate does not meet the specific ratio required by the reaction.

As the process is continued, the liquid product fed to the preheater 41 is heated at 210 to 260 ℃ to obtain 60 parts by weight of styrene-acrylonitrile copolymer and 40 parts by weight of volatile mixed gas. The styrene-acrylonitrile copolymer and the volatile gas mixture are separated by the vacuum dealkylator 42, the styrene-acrylonitrile copolymer is sent out by two gear pumps 43 and is subjected to a subsequent granulation and storage step, and the volatile gas mixture is continuously sent to the pre-condenser 51.

Referring to fig. 1,3 and 4, the volatilized mixed gas enters the first front condensing space portion 5121 through the front gas inlet 5111 of the front condenser 51 and is condensed, at this time, the styrene-acrylonitrile oligomer in the volatilized mixed gas is condensed to form oligomer condensate, and is discharged through the first front liquid outlet 5113, and the remaining uncondensed volatilized mixed gas (containing unreacted monomer and solvent) from which the styrene-acrylonitrile oligomer is removed flows into the second front condensing space portion 5122 through the front condensing gap 5133 and is condensed in the second front condensing space portion 5122 to form recycled monomer condensate, and is then transferred to the recycled monomer temporary storage tank 71 through the second front liquid outlet 5114 for temporary storage. The volatile mixed gas that is not condensed in the second front condensing space portion 5122 is further transported to the rear condenser 61 through the front gas outlet 5112 for second condensation. Referring to fig. 5, the non-condensed volatile mixed gas in the second front condensation space portion 5122 enters the rear condensation space 612 through the rear gas inlet 6111 to be condensed to form a recovered monomer condensate, and then is transported to the recovered monomer temporary storage tank 71 through the rear gas outlet 6112 for temporary storage, and the non-condensed volatile mixed gas in the rear condensation space 612 is discharged through the rear gas outlet 6113. The recovered monomer condensate in the recovered monomer temporary storage tank 71 is finally transferred back to the recovered monomer storage tank 13 to continue the reaction. It should be noted that the temperature range in the front air inlet 5111 of the front condensation shell 511 is 80 ℃ to 140 ℃, the temperature ranges in the two front air outlets 5112 of the front condensation shell 511 are 35 ℃ to 60 ℃, the temperature ranges in the two rear air inlets 6111 of the rear condensation shell 611 are 35 ℃ to 60 ℃, and the temperature range in the rear air outlet 6113 of the rear condensation shell 611 is 0 ℃ to 10 ℃. In this embodiment, the temperature in the front air inlet 5111 of the front condensation shell 511 is 110 ℃, the temperatures in the two front air outlets 5112 of the front condensation shell 511 are 40 ℃ respectively, the temperatures in the two rear air inlets 6111 of the rear condensation shell 611 are 40 ℃ respectively, and the temperature in the rear air outlet 6113 of the rear condensation shell 611 is 1 ℃.

It should be noted that in the first embodiment, the pre-condenser 51 is designed such that the styrene-acrylonitrile oligomer in the volatilized mixed gas is condensed to form an oligomer condensate when the volatilized mixed gas enters the first pre-condensing space 5121, and then flows out from the first pre-liquid outlet 5113, and the remaining uncondensed volatilized mixed gas from which the styrene-acrylonitrile oligomer is removed flows into the second pre-condensing space 5122 through the pre-condensing notch 5133, is condensed in the second pre-condensing space 5122 to form a recovered monomer condensate, and then flows out from the second pre-liquid outlet 5114 for recovery. Also, since the front condensation apertures 5133 of the front condensation partition 513 are configured to be spaced from the bottom of the front condensation shell 511, the oligomer condensate can be blocked from flowing to the second front condensation space 5122 while avoiding the oligomer condensate from being present in the recovered monomer condensate. Therefore, as can be seen from the foregoing, when the volatilized mixed gas is in the first pre-condensation space 5121, the styrene-acrylonitrile oligomer is removed by a condensation method, so that the content of the styrene-acrylonitrile oligomer in the volatilized mixed gas entering the second pre-condensation space 5122 is greatly reduced, and further the content of the styrene-acrylonitrile oligomer in the recovered monomer condensate is also greatly reduced, and the recovered monomer condensate is not mixed with the oligomer condensate, so that the apparatus of the present invention can reduce the content of the styrene-acrylonitrile oligomer in the recovered monomer condensate recovered subsequently.

In addition, in the first embodiment, by the design of the rear condenser 61, the unreacted monomer and the solvent (i.e., the volatile mixed gas) that are not condensed in the second front condensation space portion 5122 of the front condenser 51 can be condensed and recovered for the second time, and thus the waste of the unreacted monomer and the solvent can be further reduced.

In summary, since the apparatus of the present invention further comprises the front condenser 51 disposed downstream of the vacuum dealkylator 42, and the front condensation space 512 of the front condenser 51 is divided into the first front condensation space 5121 and the second front condensation space 5122 by the front condensation partition 513, and each front condensation partition 513 has the front condensation gap 5133 spaced from the bottom of the front condensation shell 511, the apparatus of the present invention can reduce the content of styrene-acrylonitrile oligomer in the recovered monomer condensate recovered subsequently, and thus the object of the present invention can be achieved.

The above description is only an example of the present invention, and the scope of the present invention should not be limited thereby, and all the simple equivalent changes and modifications made according to the claims and the contents of the specification of the present invention are included in the scope of the present invention.