A maleic anhydride device reactor outlet salt leakage detection system

Abstract

The utility model relates to the field of maleic anhydride device, specifically relates to a maleic anhydride device reactor outlet salt leakage detection system, including oxidation reactor, fused salt collection jar, salt leakage detection tuning fork switch, heat exchanger and steam pocket, the oxidation reactor bottom outlet is equipped with reactor outlet pipeline, and reactor outlet pipeline is connected to heat exchanger, and heat exchanger is connected with reactant heat exchange outlet pipeline, and reactant is into heat exchanger and carries out heat exchange through reactor outlet pipeline, and is discharged by reactant heat exchange outlet pipeline after heat exchange, the top of heat exchanger is connected with steam pocket, the bottom of reactor outlet pipeline is connected with fused salt collection jar, and fused salt collection jar is provided with salt leakage detection tuning fork switch, and is used for detecting whether fused salt collection jar exists fused salt. The application of tuning fork switch in maleic anhydride reactor can provide real-time online detection for the salt leakage condition of reactor tube plate and tube bundle in time for production workshop, and provide support for protecting reactor and post-system heat exchanger equipment.

Description

Technical Field

[0001] This utility model relates to the field of maleic anhydride equipment, specifically to a salt leakage detection system at the reactor outlet of a maleic anhydride equipment. Background Technology

[0002] The maleic anhydride oxidation reactor has a large diameter, many distributed tubes, and high reaction temperature. The molten salt is corrosive, and there is a possibility of molten salt leakage during long-term operation. Once the molten salt leaks into the reactor outlet pipeline and is carried into the downstream system, it will cause product defects and block the downstream system heat exchangers, making the unit unable to operate. Therefore, an effective monitoring method is needed to detect and reduce losses in a timely manner. Summary of the Invention

[0003] In view of the defects of the prior art, the present invention uses a high-temperature tuning fork switch installed on the molten salt collection tank at the bottom of the reactor outlet pipeline to detect the leakage of molten salt from the reactor tubes or tube sheet into the reaction outlet pipeline.

[0004] To achieve the above objectives, the specific technical solution adopted by this utility model is as follows: a maleic anhydride reactor outlet salt leakage detection system, comprising an oxidation reactor, a molten salt collection tank, a salt leakage detection tuning fork switch, a heat exchanger, and a steam drum; the bottom outlet of the oxidation reactor is provided with a reactor outlet pipeline, which is connected to the heat exchanger, and the heat exchanger is connected to a reactant heat exchange outlet pipeline, through which the reactants enter the heat exchanger for heat exchange, and are discharged from the reactant heat exchange outlet pipeline after heat exchange; a steam drum is connected above the heat exchanger; the bottom of the reactor outlet pipeline is connected to a molten salt collection tank, and a salt leakage detection tuning fork switch is installed on the molten salt collection tank for detecting whether molten salt exists in the molten salt collection tank.

[0005] Furthermore, the oxidation reactor is connected to a molten salt circulation pump via a molten salt circulation pipeline, and a temperature controller and a molten salt control valve are installed on the molten salt circulation pipeline.

[0006] Furthermore, the maleic anhydride unit reactor outlet salt leakage detection system also includes a mixer, an air feed line and a butane vapor feed line connected to the inlet of the mixer, and the mixer outlet connected to the inlet of the oxidation reactor via a pipeline.

[0007] Furthermore, the bottom of the molten salt collection tank is equipped with a drain valve for discharging debris from the molten salt collection tank; a flange pipe platform is welded to the side of the molten salt collection tank, and a salt leakage detection tuning fork switch is installed on the flange pipe platform.

[0008] Furthermore, a hole is made at the bottom of the reactor outlet pipeline and a molten salt collection tank is welded thereon. A hole is made on the side of the molten salt collection tank and a DN50, CL150 flange pipe platform is welded thereon. A salt leakage detection tuning fork switch is installed on the flange pipe platform.

[0009] Furthermore, the heat exchanger and the steam drum are connected to form a loop; the circulating medium outlet of the heat exchanger is connected to the steam drum inlet from bottom to top through the heat exchange medium outlet pipeline, and the bottom outlet of the steam drum is connected to the circulating medium inlet of the heat exchanger through the heat exchange medium inlet pipeline.

[0010] Furthermore, a steam drum drain pipe is connected to the bottom of the steam drum.

[0011] Furthermore, the top outlet of the steam drum is connected to a steam outlet pipeline, which supplies steam to the boundary area; the inlet of the steam drum is connected to a steam drum water supply pipeline.

[0012] The beneficial effects of this invention are as follows: the application of tuning fork switches in maleic anhydride reactors can provide real-time online detection of salt leakage in reactor tube sheets and tube bundles in a timely and effective manner in the production workshop, providing support for the protection of reactors and downstream system heat exchanger equipment. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the salt leakage detection system at the reactor outlet of the maleic anhydride device of this utility model; In the diagram: 1. Oxidation reactor, 2. Mixer, 3. Molten salt circulation pump, 4. Molten salt collection tank, 5. Salt leakage detection tuning fork switch, 6. Heat exchanger, 7. Steam drum, 8. Air feed line, 9. Butane steam feed line, 10. Reactor outlet line, 11. Reactant heat exchange outlet line, 12. Molten salt circulation line, 13. Temperature controller, 14. Molten salt control valve, 15. Heat exchange medium outlet line, 16. Heat exchange medium inlet line, 17. Steam drum drain line, 18. Steam outlet line, 19. Steam drum feedwater line. Detailed Implementation

[0014] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0015] See appendix Figure 1A maleic anhydride reactor outlet salt leakage detection system includes an oxidation reactor 1, a mixer 2, a molten salt circulation pump 3, a molten salt collection tank 4, a salt leakage detection tuning fork switch 5, a heat exchanger 6, and a steam drum 7. Air feed line 8 and butane vapor feed line 9 are connected to the inlet of mixer 2, and the outlet of mixer 2 is connected to the inlet of oxidation reactor 1 via a pipeline. The bottom outlet of oxidation reactor 1 is provided with reactor outlet line 10, which is connected to heat exchanger 6. Heat exchanger 6 is connected to reactant heat exchange outlet line 11. Reactants enter heat exchanger 6 through reactor outlet line 11 for heat exchange, and are discharged through reactant heat exchange outlet line 12 after heat exchange. A steam drum 7 is connected above heat exchanger 6. Oxidation reactor 1 is connected to molten salt circulation pump 3 through molten salt circulation line 12. Temperature controller 13 and molten salt control valve 14 are installed on molten salt circulation line. Molten salt collection tank 4 is connected to the bottom of reactor outlet line 10. A salt leakage detection tuning fork switch 5 is installed on molten salt collection tank 4 to detect whether there is molten salt in molten salt collection tank 4.

[0016] Based on the above technical solution, in the production of maleic anhydride, the raw material n-butane and air are fully mixed in a certain proportion in mixer 2 and then enter oxidation reactor 1. The reaction occurs in the tubes of the oxidation reactor, which is filled with a certain amount of catalyst. Molten salt is the heat transfer and storage medium of the core oxidation reaction. It provides a stable heat source for the oxidation reaction in the initial stage. After the reaction occurs, the molten salt cooler removes some of the excess heat generated by the oxidation reaction. The setting method of the molten salt cooler can adopt the existing technical solution.

[0017] The molten salt detection at the outlet of the maleic anhydride oxidation reactor 1 is based on the principle of a tuning fork switch. The working principle of the tuning fork switch is that the piezoelectric crystal installed on the base causes the tuning fork to vibrate at a certain resonant frequency. When the tuning fork of the tuning fork switch comes into contact with the medium being measured, the frequency and amplitude of the tuning fork will change. These changes of the tuning fork level switch are detected by the intelligent circuit and converted into a switching signal and transmitted to the central control DCS screen.

[0018] The reactor outlet temperature exceeds 400℃, which is quite high. Under these conditions, conventional analytical instruments are often insufficient, and the characteristics of the molten salt and the reactor itself make sampling and cooling analysis difficult. Therefore, a tuning fork was chosen to detect salt leakage, which not only meets the operational requirements but also offers economic and practical advantages.

[0019] The application of tuning fork switches in oxidation reactors can provide real-time online monitoring for the production workshop, enabling timely and effective detection of salt leakage in the reactor tube sheet and tube bundle. Combined with alarm information settings in conjunction with DCS, it provides support for protecting the reactor and downstream system heat exchanger equipment.

[0020] Furthermore, according to the inlet and outlet flow of the oxidation reactor 1, a hole is made at the bottom of the reactor outlet pipeline 10 and a molten salt collection tank 4 is welded thereon. The bottom of the molten salt collection tank 4 is equipped with a drain valve, which is opened when necessary to drain debris from the molten salt collection tank. A hole is made on the side of the molten salt collection tank 4 and a DN50, CL150 flange is welded thereon. A salt leakage detection tuning fork switch 5 is installed on the flange. When molten salt leaks, the molten salt enters the molten salt collection tank 4 from the reactor outlet pipeline 10, covering the tuning fork and changing the vibration frequency of the tuning fork to issue an alarm signal.

[0021] Furthermore, the heat exchanger 6 and the steam drum 7 are connected to form a loop; the circulating medium outlet of the heat exchanger 6 is connected to the steam drum inlet from bottom to top through the heat exchange medium outlet pipeline 15, and the bottom outlet of the steam drum is connected to the circulating medium inlet of the heat exchanger 6 through the heat exchange medium inlet pipeline 16.

[0022] Furthermore, a steam drum drain line 17 is connected to the bottom of the steam drum 7, and a control valve is installed on the steam drum drain line 17.

[0023] Furthermore, the top outlet of the steam drum 7 is connected to a steam outlet pipeline 18, which sends steam to the boundary area. A control valve is installed on the steam outlet pipeline 18. The steam drum inlet is connected to a steam drum water supply pipeline 19, which is equipped with a control valve.

[0024] Based on the above technical solution, a water circulation is formed between the steam drum 7 and the heat exchanger 6. The reactants from the outlet of the oxidation reactor 1 enter the heat exchanger 6 as the hot-side medium for cooling, while the circulating water in the steam drum enters the heat exchanger 6 as the cold-side medium to cool the reactants. The steam-water mixture in the heat exchanger 6 rises and enters the steam drum 7 through the heat exchange medium outlet pipeline 15. Inside the steam drum 7, it is separated by a steam-water separator. The separated saturated steam enters the steam outlet pipeline 18 and is sent to the boundary area, while the separated water returns to the heat exchanger 6 through the heat exchange medium inlet pipeline 16 to continue the circulation. The steam drum inlet is connected to the steam drum feed water pipeline 19 to replenish the circulating water. The steam drum drain pipeline 17 at the bottom of the steam drum 7 can discharge impurities from the steam drum. The steam drum structure adopts the existing technology.

[0025] It should be noted that the parts of this utility model not described in detail are existing technologies.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0027] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0028] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0029] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0030] The above-listed embodiments are merely preferred embodiments of this utility model. Obviously, this utility model is not limited to the above embodiments and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of this utility model should be considered within the protection scope of this utility model.

Claims

1. A salt leakage detection system at the reactor outlet of a maleic anhydride unit, characterized in that: The system includes an oxidation reactor, a molten salt collection tank, a salt leakage detection tuning fork switch, a heat exchanger, and a steam drum. The oxidation reactor has a reactor outlet pipeline at its bottom outlet, which connects to the heat exchanger. The heat exchanger is connected to a reactant heat exchange outlet pipeline, through which reactants enter the heat exchanger for heat exchange and are discharged. A steam drum is connected above the heat exchanger. A molten salt collection tank is connected to the bottom of the reactor outlet pipeline, and a salt leakage detection tuning fork switch is installed on the molten salt collection tank to detect the presence of molten salt.

2. The maleic anhydride reactor outlet salt leakage detection system according to claim 1, characterized in that: The oxidation reactor is connected to a molten salt circulation pump via a molten salt circulation pipeline, and a temperature controller and a molten salt control valve are installed on the molten salt circulation pipeline.

3. The maleic anhydride reactor outlet salt leakage detection system according to claim 1, characterized in that: It also includes a mixer, an air feed line and a butane vapor feed line connected to the inlet of the mixer, and the outlet of the mixer connected to the inlet of the oxidation reactor via a pipeline.

4. The maleic anhydride reactor outlet salt leakage detection system according to claim 1, characterized in that: The bottom of the molten salt collection tank is equipped with a drain valve to discharge debris from the molten salt collection tank; a flange pipe platform is welded to the side of the molten salt collection tank, and a salt leakage detection tuning fork switch is installed on the flange pipe platform.

5. A maleic anhydride reactor outlet salt leakage detection system according to claim 4, characterized in that: The bottom of the reactor outlet pipeline is perforated and a molten salt collection tank is welded thereon. A DN50, CL150 flange pipe platform is perforated on the side of the molten salt collection tank and welded thereon. A salt leakage detection tuning fork switch is installed on the flange pipe platform.

6. The maleic anhydride reactor outlet salt leakage detection system according to claim 1, characterized in that: The heat exchanger and the steam drum are connected to form a loop; the circulating medium outlet of the heat exchanger is connected to the steam drum inlet from bottom to top through the heat exchange medium outlet pipeline, and the bottom outlet of the steam drum is connected to the circulating medium inlet of the heat exchanger through the heat exchange medium inlet pipeline.

7. The maleic anhydride reactor outlet salt leakage detection system according to claim 1, characterized in that: The bottom of the steam drum is connected to a steam drum drainage pipeline.

8. The maleic anhydride reactor outlet salt leakage detection system according to claim 1, characterized in that: The top outlet of the steam drum is connected to a steam outlet pipeline, which supplies steam to the boundary area; the inlet of the steam drum is connected to a steam drum water supply pipeline.

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