Oxidation reaction device for pyromellitic dianhydride and application method

Abstract

The invention discloses an oxidation reaction device for pyromellitic dianhydride. The oxidation reaction device comprises a raw material vaporization mechanism and a reaction mechanism, wherein the raw material vaporization mechanism is provided with a plurality of durene feeding atomizing nozzles; the raw material vaporization mechanism is communicated with a raw material inlet of the reactor; the axial flow pump is communicated with the molten salt outlet of the reactor; the electric heater is arranged in the reactor or is arranged between the reactor and the axial flow pump; and the cooling mechanism is communicated with the axial flow pump. The invention also discloses an application method of the oxidation reaction device for pyromellitic dianhydride. According to the oxidation reaction device for pyromellitic dianhydride and the application method, the technical problems that when a durene vaporizer is adopted for vaporizing raw materials in a traditional process, the temperature of the vaporizer does not have a control means, the fluctuation range is large, and potential safety hazards exist are solved.

Description

Technical Field

[0001] This application belongs to the technical field of oxidation reaction devices, and particularly relates to an oxidation reaction device for pyromellitic dianhydride and an application method thereof. Background Art

[0002] The gas-phase oxidation of 1,2,4,5-tetramethylbenzene to pyromellitic dianhydride is a complex multiphase catalytic process, and the product is a mixture of oxygen-containing compounds with a wide range, including anhydrides, aldehydes, and acid compounds. The reaction of 1,2,4,5-tetramethylbenzene with air is a thermodynamically irreversible reaction and is not limited by chemical equilibrium. Since both the main and side reactions are highly exothermic reactions, especially the complete oxidation reaction is highly competitive thermodynamically, high temperature will inevitably lead to the progress of the complete oxidation reaction, resulting in the release of more heat, making it difficult to control the temperature of the catalyst bed layer and even causing the phenomenon of "temperature runaway", burning out the catalyst. Therefore, the reaction temperature must be limited within the operating temperature range of the catalyst. Different types of catalysts have different reaction temperatures. Usually, the oxidation of 1,2,4,5-tetramethylbenzene to pyromellitic dianhydride requires strict control of the reaction temperature at 420 - 440 °C.

[0003] Currently, 1,2,4,5-tetramethylbenzene is fed in liquid phase, and the traditional process requires a vaporizer to be set up, where liquid 1,2,4,5-tetramethylbenzene contacts high-temperature air for vaporization. If the temperature of the 1,2,4,5-tetramethylbenzene vaporizer is too high, the heavy components accumulated in the vaporizer are prone to spontaneous combustion, causing explosion accidents; if the temperature of the vaporizer is too low, the raw materials cannot be vaporized, resulting in the interruption of the reaction. When the liquid phase enters the reactor, it will violently vaporize and react, causing overpressure of the equipment. There is no temperature control means for the 1,2,4,5-tetramethylbenzene vaporizer in the traditional process, and the fluctuation range is large, with great potential safety hazards. Summary of the Invention

[0004] This application aims to at least solve to a certain extent the technical problem that there is no temperature control means for the vaporizer during the vaporization of raw materials using a 1,2,4,5-tetramethylbenzene vaporizer in the traditional process, with a large fluctuation range and potential safety hazards. For this reason, this application provides an oxidation reaction device for pyromellitic dianhydride and an application method thereof.

[0005] The technical solution of this application is as follows:

[0006] One aspect of this application provides an oxidation reaction device for pyromellitic dianhydride, including:

[0007] A raw material vaporization mechanism provided with a plurality of 1,2,4,5-tetramethylbenzene feed atomizing nozzles, one end of the 1,2,4,5-tetramethylbenzene feed atomizing nozzle is connected to the 1,2,4,5-tetramethylbenzene raw material conveying pipeline;

[0008] A reactor, the other end of the 1,2,4,5-tetramethylbenzene feed atomizing nozzle is connected to the raw material inlet of the reactor, and the reactor is provided with a reactor molten salt inlet and a reactor molten salt outlet;

[0009] Axial flow pump, which is connected to the molten salt outlet of the reactor;

[0010] Electric heater, which is arranged inside the reactor. One end of the electric heater is connected to the molten salt inlet of the reactor, and the other end is connected to the molten salt outlet of the reactor, or it is arranged between the reactor and the axial flow pump. One end of the electric heater is connected to the axial flow pump, and the other end is connected to the molten salt inlet of the reactor; Cooling mechanism, which is connected to the axial flow pump.

[0011] Further, the raw material vaporization mechanism further includes:

[0012] High-temperature air pipeline, on the outer circumference of which the mesitylene feed atomizing nozzle is arranged and is connected to the high-temperature air pipeline;

[0013] Vaporization section, one end of which is connected to the high-temperature air pipeline, and the other end is connected to the raw material inlet of the reactor.

[0014] Further, the mesitylene feed atomizing nozzle is provided with a high-temperature atomizing air inlet and a liquid-phase mesitylene inlet. The high-temperature atomizing air inlet is connected to the high-temperature atomizing air supply pipeline, and the liquid-phase mesitylene inlet is connected to the liquid-phase mesitylene supply pipeline.

[0015] Further, the number of the mesitylene feed atomizing nozzles is an even number and is symmetrically arranged uniformly on the cross-section of the high-temperature air pipeline.

[0016] Further, the axial flow pump is provided with a first axial flow pump inlet, a second axial flow pump inlet, a first axial flow pump outlet and a second axial flow pump outlet;

[0017] The first axial flow pump inlet is connected to the molten salt outlet of the reactor.

[0018] Further, the cooling mechanism includes:

[0019] Cooler regulating valve, one end of which is connected to the second axial flow pump outlet, and the other end is connected to the molten salt inlet of the molten salt cooler;

[0020] Molten salt cooler, the molten salt outlet of which is connected to the second axial flow pump inlet.

[0021] Further, the electric heater is arranged inside the reactor. One end of the electric heater is connected to the molten salt inlet of the reactor, and the other end is connected to the molten salt outlet of the reactor.

[0022] Further, the electric heater is arranged between the reactor and the axial flow pump. One end of the electric heater is communicated with the molten salt inlet of the reactor, and the other end is communicated with the first outlet of the axial flow pump.

[0023] Another aspect of the present application provides an application method for an oxidation reaction device for pyromellitic dianhydride, including:

[0024] Atomize the liquid-phase 1,2,4,5-tetramethylbenzene, and then perform vaporization treatment to obtain the vaporized raw material;

[0025] The vaporized raw material enters from the raw material inlet of the reactor, undergoes catalytic oxidation reaction and releases heat through the tube side, and the reaction product flows out from the bottom of the reactor;

[0026] The heated molten salt flows out from the molten salt outlet of the reactor, enters the axial flow pump through the first inlet of the axial flow pump, is boosted by the axial flow pump and then is divided into two paths. One path flows out from the second outlet of the axial flow pump, passes through the regulating valve of the molten salt cooler, enters the molten salt inlet of the molten salt cooler, returns to the second inlet of the axial flow pump after heat extraction and temperature reduction from the molten salt outlet of the molten salt cooler, and the other path flows out from the first outlet of the axial flow pump, enters from the bottom of the electric heater, exits from the upper part and then returns to the reactor to complete the circulating heat extraction of the molten salt.

[0027] Further, the vaporization treatment of the liquid-phase 1,2,4,5-tetramethylbenzene through the 1,2,4,5-tetramethylbenzene feed atomizing nozzle includes:

[0028] The liquid-phase 1,2,4,5-tetramethylbenzene enters the 1,2,4,5-tetramethylbenzene feed atomizing nozzle through the liquid-phase 1,2,4,5-tetramethylbenzene inlet, the high-temperature atomizing air enters the 1,2,4,5-tetramethylbenzene feed atomizing nozzle through the high-temperature atomizing air inlet. After the liquid-phase 1,2,4,5-tetramethylbenzene is atomized by the high-temperature atomizing air in the 1,2,4,5-tetramethylbenzene feed atomizing nozzle, the atomized raw material is obtained;

[0029] The atomized raw material enters the high-temperature air pipeline, mixes with the high-temperature air and enters the vaporization section to complete vaporization, and the vaporized raw material is obtained.

[0030] The embodiments of the present application at least have the following beneficial effects:

[0031] The present application provides an oxidation reaction device for pyromellitic dianhydride and an application method thereof. The vaporizer is cancelled, and the 1,2,4,5-tetramethylbenzene feed atomizing nozzle is set to directly feed the vaporized raw material into the oxidation reactor, ensuring the vaporization effect and no accumulation of heavy components, so as to improve the operation stability and safety of the oxidation reaction device. Description of the Drawings

[0032] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0033] Figure 1 It is a schematic structural diagram of an oxidation reaction device for pyromellitic dianhydride provided in Embodiment 1 of the present application;

[0034] Figure 2 It is a schematic structural diagram of an oxidation reaction device for pyromellitic dianhydride provided in Embodiment 2 of the present application.

[0035] Reference numerals:

[0036] 1 - Mesitylene feed atomizing nozzle; 2 - Reactor; 3 - Axial flow pump; 4 - Electric heater; 5 - High-temperature air pipeline; 6 - Vaporization section; 7 - Cooler regulating valve; 8 - Molten salt cooler;

[0037] 11 - High-temperature atomizing air inlet; 12 - Liquid-phase mesitylene inlet;

[0038] 21 - Reactor molten salt outlet; 22 - Reactor molten salt inlet;

[0039] 31 - First inlet of the axial flow pump; 32 - Second inlet of the axial flow pump; 33 - First outlet of the axial flow pump; 34 - Second outlet of the axial flow pump. Specific embodiments

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0041] In addition, the present application may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0042] The following describes the present application in conjunction with the accompanying drawings and with reference to specific embodiments:

[0043] Embodiment 1

[0044] Combined with Figure 1As shown in the figure, an aspect of the present application provides an oxidation reaction device for pyromellitic dianhydride, including: a raw material vaporization mechanism provided with a plurality of mesitylene feed atomizing nozzles 1, a reactor 2, an axial flow pump 3, an electric heater 4 and a cooling mechanism. One end of the mesitylene feed atomizing nozzle 1 is communicated with the mesitylene raw material conveying pipeline, and the other end is communicated with the raw material inlet of the reactor 2. The reactor 2 is provided with a reactor molten salt outlet 21 and a reactor molten salt inlet 22; the axial flow pump 3 is communicated with the reactor molten salt outlet 21; the cooling mechanism is communicated with the axial flow pump 3.

[0045] In the embodiment of the present application, the raw material vaporization mechanism further includes a high-temperature air pipeline 5 and a vaporization section 6. The mesitylene feed atomizing nozzle 1 is arranged on the outer circumference of the high-temperature air pipeline 5 and is communicated with the high-temperature air pipeline 5; one end of the vaporization section 6 is communicated with the high-temperature air pipeline 5, and the other end is communicated with the raw material inlet of the reactor 2. Since the raw materials for the pyromellitic dianhydride oxidation reaction are mesitylene and air, and high-temperature air is one of the reaction raw materials, the atomized mesitylene needs to be mixed with high-temperature air and then enter the reactor 2 for reaction. The mesitylene coming out of the mesitylene atomizing nozzle is in the form of tiny mesitylene droplets (1-200 μm), which need to be in contact with high-temperature air for vaporization, and then the gaseous raw materials enter the reactor 2 for reaction. Therefore, the raw material vaporization mechanism is also provided with a vaporization section 6 to ensure that there is enough residence time to complete the vaporization of the mesitylene droplets.

[0046] In the embodiment of the present application, the mesitylene feed atomizing nozzle 1 is provided with a high-temperature atomizing air inlet 11 and a liquid-phase mesitylene inlet 12. The high-temperature atomizing air inlet 11 is communicated with the high-temperature atomizing air supply pipeline, and the liquid-phase mesitylene inlet 12 is communicated with the liquid-phase mesitylene supply pipeline. The mesitylene feed atomizing nozzle 1 is preferably a throat-type nozzle, and its atomization mechanism is: the liquid feed is impacted and broken by the high-speed jet of high-temperature air, and the feed forms a strongly turbulent pulsating jet when entering the high-temperature air pipeline 5, and collides with the surrounding medium and breaks.

[0047] In the embodiment of the present application, the number of the mesitylene feed atomizing nozzles 1 is an even number and is evenly and symmetrically arranged on the cross-section of the high-temperature air pipeline 5. The purpose of having an even number is to evenly and symmetrically arrange the feed nozzles on the high-temperature air pipeline 5, and the symmetrically ejected materials are conducive to colliding at the center of the pipeline, preventing impact on the pipe wall; at the same time, the atomized feed is more evenly distributed on the cross-section. The specific quantity is determined according to the device scale and the selected nozzle capacity, and 2-8 are recommended. And evenly and symmetrically arranging the mesitylene feed atomizing nozzles 1 on the high-temperature air pipeline 5, the symmetrically ejected materials are conducive to colliding at the center of the pipeline, preventing impact on the pipe wall; at the same time, the atomized feed is more evenly distributed on the cross-section.

[0048] In the embodiment of the present application, the axial flow pump 3 is provided with a first axial flow pump inlet 31, a second axial flow pump inlet 32, a first axial flow pump outlet 33 and a second axial flow pump outlet 34; the first axial flow pump inlet 31 is communicated with the reactor molten salt outlet 21.

[0049] In the embodiment of the present application, the cooling mechanism includes a cooler regulating valve 7 and a molten salt cooler 8. One end of the cooler regulating valve 7 is communicated with the second axial flow pump outlet 34, and the other end is communicated with the molten salt inlet of the molten salt cooler 8; the molten salt outlet of the molten salt cooler 8 is communicated with the second axial flow pump inlet 32.

[0050] In the embodiment of the present application, the electric heater 4 is arranged between the reactor 2 and the axial flow pump 3. One end of the electric heater 4 is communicated with the reactor molten salt inlet 22, and the other end is communicated with the first axial flow pump outlet 33. The electric heater 4 can also be arranged in the area with a relatively high molten salt flow rate, and no specific limitation is made here. After the molten salt is boosted by the axial flow pump 3, it first passes through the electric heater 4 and then is sent to the reactor 2. The molten salt flow rate in the electric heater 4 is high and there is no dead zone. The temperature of the reactor 2 can be jointly controlled by the cooler regulating valve 7 and the electric heater 4. During normal operation, the temperature of the reactor 2 is controlled by the cooler regulating valve 7. When the temperature of the reactor 2 is too low and the cooler regulating valve 7 is fully closed, the electric heater 4 is turned on to increase the temperature of the reactor 2, realizing the automatic control of the temperature of the reactor 2.

[0051] When the oxidation reaction device for pyromellitic dianhydride provided by the embodiment of the present application is in use, the liquid-phase mesitylene feed is transported from the liquid-phase mesitylene raw material transport pipeline to the mesitylene feed atomizing nozzle 1 and atomized by the mesitylene feed atomizing nozzle 1. The atomizing medium is high-temperature atomizing air. The atomized raw material is mixed with the high-temperature air and enters the vaporization section 6 to complete vaporization, enters from the raw material inlet of the reactor 2, undergoes a catalytic oxidation reaction and releases heat through the tube side, and the reaction product comes out from the bottom of the reactor 2. The heat released by the reaction is transferred to the molten salt in the shell side of the reactor 2. The molten salt flows out from the molten salt outlet at the upper part of the reactor 2 and enters the axial flow pump 3 from the first axial flow pump inlet 31. After the molten salt is boosted by the axial flow pump 3, it is divided into two paths. One path flows out from the second axial flow pump outlet 34, passes through the cooler regulating valve 7 and enters the molten salt cooler 8 from the molten salt inlet at the bottom of the molten salt cooler 8, and returns to the second axial flow pump inlet 32 from the molten salt outlet at the upper part of the molten salt cooler 8 after heat extraction and temperature reduction; the other path flows out from the second axial flow pump outlet 34 and enters the electric heater 4. The electric heater 4 is arranged between the axial flow pump 3 and the reactor 2. The molten salt enters from the bottom of the electric heater 4 and exits from the upper part, and returns to the reactor 2 to complete the cyclic heat extraction of the molten salt. The temperature of the reactor 2 is jointly controlled by the cooler regulating valve 7 and the electric heater 4.

[0052] Example Two

[0053] The difference between this embodiment and the first embodiment is that the electric heater 4 is arranged inside the reactor 2. One end of the electric heater 4 is communicated with the molten salt inlet 22 of the reactor, and the other end is communicated with the molten salt outlet 21 of the reactor. The molten salt is directly sent to the reactor 2 after being boosted by the axial flow pump 3. The flow rate of the molten salt in the electric heater 4 is high and there is no dead zone. The temperature of the reactor 2 can be jointly controlled by the molten salt cooler 8, the cooler regulating valve 7 and the electric heater 4. During normal operation, the temperature of the reactor 2 is controlled by the cooler regulating valve 7. When the temperature of the reactor 2 is too low and the cooler regulating valve 7 is fully closed, the electric heater 4 is turned on to increase the temperature of the reactor 2, so as to realize the automatic control of the temperature of the reactor 2. The rest is exactly the same as the first embodiment.

[0054] When the oxidation reaction device for pyromellitic dianhydride provided by the embodiment of the present application is in use, the liquid-phase mesitylene feed is transported from the liquid-phase mesitylene raw material transport pipeline to the mesitylene feed atomizing nozzle 1 and atomized by the mesitylene feed atomizing nozzle 1. The atomizing medium is high-temperature atomizing air. The atomized raw material is mixed with the high-temperature air and enters the vaporization section 6 to complete vaporization, enters from the raw material inlet of the reactor 2, undergoes catalytic oxidation reaction and releases heat through the tube side, and the reaction product comes out from the bottom of the reactor 2. The heat released by the reaction is transferred to the molten salt in the shell side of the reactor 2. The molten salt flows out from the molten salt outlet at the upper part of the reactor 2 and enters the axial flow pump 3 from the first inlet 31 of the axial flow pump. After being boosted by the axial flow pump 3, the molten salt is divided into two paths. One path flows out from the second outlet 34 of the axial flow pump, passes through the cooler regulating valve 7 and enters the molten salt cooler 8 from the molten salt inlet at the bottom of the molten salt cooler 8, returns to the second inlet 32 of the axial flow pump from the molten salt outlet at the upper part of the molten salt cooler 8 after heat extraction and temperature reduction; the other path flows out from the second outlet 34 of the axial flow pump and enters the electric heater 4. The electric heater 4 is arranged inside the reactor 2. The molten salt enters from the bottom of the electric heater 4 and exits from the upper part, and returns to the reactor 21 to complete the cyclic heat extraction of the molten salt. The temperature of the reactor 2 is jointly controlled by the cooler regulating valve 7 and the electric heater 4.

[0055] Embodiment III

[0056] Another aspect of the present application provides an application method for an oxidation reaction device for pyromellitic dianhydride, including:

[0057] S1: Atomize the liquid-phase mesitylene and then perform vaporization treatment to obtain the vaporized raw material;

[0058] S2: The vaporized raw material enters from the raw material inlet of the reactor 2, undergoes catalytic oxidation reaction and releases heat through the tube side, and the reaction product flows out from the bottom of the reactor 2;

[0059] S3: The heated molten salt flows out from the molten salt outlet 21 of the reactor, enters the first inlet 31 of the axial flow pump 3, is boosted by the axial flow pump 3, and then divides into two paths. One path flows out from the second outlet 34 of the axial flow pump, enters the molten salt inlet of the molten salt cooler 8 after passing through the cooler regulating valve 7, returns to the second inlet 32 of the axial flow pump after heat extraction and temperature reduction from the molten salt outlet of the molten salt cooler 8. The other path flows out from the first outlet 33 of the axial flow pump, enters from the bottom of the electric heater 4, exits from the upper part, and then returns to the reactor 2 to complete the circulating heat extraction of the molten salt.

[0060] Among them, S1 vaporizing the liquid-phase durene through the durene feed atomizing nozzle 1 includes:

[0061] S11: The liquid-phase durene enters the durene feed atomizing nozzle through the liquid-phase durene inlet 12, the high-temperature atomizing air enters the durene feed atomizing nozzle through the high-temperature atomizing air inlet 11. After the liquid-phase durene is atomized by the high-temperature atomizing air in the durene feed atomizing nozzle, the atomized raw material is obtained, and the particle size of the atomized durene is 1 μm - 200 μm.

[0062] S12: The atomized raw material enters the high-temperature air pipeline 5, mixes with the high-temperature air, and enters the vaporization section 6 to complete vaporization, obtaining the vaporized raw material.

[0063] The technical solution of the above invention has at least the following technical effects or advantages:

[0064] 1. In this application, by setting the durene feed atomizing nozzle and the vaporization section, the vaporized raw material directly enters the reactor, ensuring the vaporization effect and no accumulation of heavy components, so as to improve the stability and safety of the operation of the oxidation reaction device.

[0065] 2. In this application, by arranging the electric heater between the axial flow pump and the reactor or inside the reactor, the molten salt flow rate in the electric heater is high and there is no dead zone, avoiding local overheating or solidification of the molten salt, preventing equipment damage and device shutdown. By jointly controlling the reactor temperature with the molten salt cooler regulating valve and the electric heater, the reactor temperature control is sensitive and automatic control is achieved.

[0066] In this application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may include the direct contact of the first and second features, or may include the first and second features not being in direct contact but in contact through other features between them. Moreover, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "under" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0067] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present application.

[0068] It should be noted that all the directional indications in the embodiments of the present application are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If this specific posture changes, the directional indications will also change accordingly.

[0069] In the present application, unless otherwise clearly defined and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0070] In addition, in the present application, the descriptions such as "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more, unless otherwise clearly and specifically defined.

[0071] In the description of this specification, the descriptions with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification.

[0072] In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0073] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present application. The scope of the present application is defined by the claims and their equivalents.

Claims

1. An oxidation reaction device for pyromellitic dianhydride, characterized in that, Comprising: A raw material vaporization mechanism provided with a plurality of mesitylene feed atomizing nozzles, one end of each mesitylene feed atomizing nozzle being connected to a mesitylene raw material conveying pipeline; A reactor, the other end of each mesitylene feed atomizing nozzle being connected to a raw material inlet of the reactor, the reactor being provided with a reactor molten salt inlet and a reactor molten salt outlet; An axial flow pump, the axial flow pump being connected to the reactor molten salt outlet; An electric heater, the electric heater being disposed inside the reactor, one end of the electric heater being connected to the reactor molten salt inlet and the other end being connected to the reactor molten salt outlet, or being disposed between the reactor and the axial flow pump, one end of the electric heater being connected to the axial flow pump and the other end being connected to the reactor molten salt inlet; A cooling mechanism, the cooling mechanism being connected to the axial flow pump.

2. The oxidation reaction device for pyromellitic dianhydride according to claim 1, characterized in that, The raw material vaporization mechanism further includes: A high-temperature air pipeline, the mesitylene feed atomizing nozzles being disposed on the outer circumference of the high-temperature air pipeline and being connected to the high-temperature air pipeline; A vaporization section, one end of the vaporization section being connected to the high-temperature air pipeline and the other end being connected to the raw material inlet of the reactor.

3. The oxidation reaction device for pyromellitic dianhydride according to claim 2, wherein: The mesitylene feed atomizing nozzle is provided with a high-temperature atomizing air inlet and a liquid-phase mesitylene inlet, the high-temperature atomizing air inlet being connected to a high-temperature atomizing air supply pipeline, and the liquid-phase mesitylene inlet being connected to a liquid-phase mesitylene supply pipeline.

4. The oxidation reaction device for pyromellitic dianhydride according to claim 2, wherein: The number of the mesitylene feed atomizing nozzles is an even number and they are symmetrically arranged uniformly on the cross-section of the high-temperature air pipeline.

5. The oxidation reaction device for pyromellitic dianhydride according to any one of claims 1-4, wherein: The axial flow pump is provided with an axial flow pump first inlet, an axial flow pump second inlet, an axial flow pump first outlet and an axial flow pump second outlet; The axial flow pump first inlet is connected to the reactor molten salt outlet.

6. The oxidation reaction device for pyromellitic dianhydride according to claim 5, characterized in that, The cooling mechanism includes: A cooler regulating valve, one end of the cooler regulating valve being connected to the axial flow pump second outlet and the other end being connected to the molten salt inlet of the molten salt cooler; A molten salt cooler, the molten salt outlet of the molten salt cooler being connected to the axial flow pump second inlet.

7. The oxidation reaction device for pyromellitic dianhydride according to claim 6, wherein: The electric heater is disposed inside the reactor, one end of the electric heater being connected to the reactor molten salt inlet and the other end being connected to the reactor molten salt outlet.

8. The oxidation reaction device for pyromellitic dianhydride according to claim 6, wherein: The electric heater is disposed between the reactor and the axial flow pump, one end of the electric heater being connected to the reactor molten salt inlet and the other end being connected to the axial flow pump first outlet.

9. A method for applying an oxidation reaction device for pyromellitic dianhydride as described in claim 7 or 8, characterized in that, Comprising: Atomizing the liquid-phase mesitylene and then subjecting it to vaporization treatment to obtain the vaporized raw material; The vaporized raw material enters from the raw material inlet of the reactor, undergoes catalytic oxidation reaction and releases heat through the tube side, and the reaction product flows out from the bottom of the reactor; The heated molten salt flows out from the molten salt outlet of the reactor, enters the axial flow pump through the first inlet of the axial flow pump, is boosted by the axial flow pump and then divides into two paths. One path flows out from the second outlet of the axial flow pump, enters the molten salt inlet of the molten salt cooler after passing through the regulating valve of the molten salt cooler, returns to the second inlet of the axial flow pump from the molten salt outlet of the molten salt cooler after heat extraction and temperature reduction, and the other path flows out from the first outlet of the axial flow pump, enters from the bottom of the electric heater, exits from the upper part and then returns to the reactor to complete the cycle heat extraction of the molten salt.

10. A method for applying the oxidation reaction device for pyromellitic dianhydride as described in claim 9, characterized in that, The vaporization treatment of liquid-phase mesitylene through the mesitylene feed atomizing nozzle includes: Liquid-phase mesitylene enters the mesitylene feed atomizing nozzle through the liquid-phase mesitylene inlet, high-temperature atomizing air enters the mesitylene feed atomizing nozzle through the high-temperature atomizing air inlet, and the liquid-phase mesitylene is atomized in the mesitylene feed atomizing nozzle by the high-temperature atomizing air to obtain the atomized raw material; The atomized raw material enters the high-temperature air pipeline, mixes with high-temperature air and enters the vaporization section to complete vaporization, obtaining the vaporized raw material.

Images