A benzene column pressure control system, a cumene production system and method

Abstract

The present invention provides a benzene column pressure control system, a cumene production system and a method, specifically relating to the technical field of cumene production. The benzene column pressure control system includes: a benzene column, a reflux drum and a disturbance device. The reflux drum is arranged at the top of the benzene column and is communicated with the benzene column. The disturbance device includes a gas pipeline and a spraying device. The spraying device is installed at the bottom of the reflux drum. One end of the gas pipeline is communicated with the spraying device, and the other end is communicated with disturbance gas. The disturbance gas enters the spraying device through the gas pipeline and is sprayed into the reflux drum by the spraying device, so that the light hydrocarbon components in the system are discharged along with the disturbance gas. By adopting the cumene production system including this control system, it can adapt to propylene with different purities, ensure the safe and stable operation of the benzene column pressure, and at the same time reduce the investment cost and operation cost.

Description

Technical Field

[0001] The present invention relates to the technical field of cumene production, and particularly relates to a benzene column pressure control system, a cumene production system and a method thereof. Background Art

[0002] Cumene is an important organic chemical raw material, mainly used for the production of phenol and acetone. In addition, cumene can also be used as a diluent for paints and enamel, for manufacturing polymerization and oxidation catalysts, and for producing products such as acetophenone, α-methylstyrene and peroxides, etc., with very wide applications.

[0003] Currently, cumene is mostly produced from liquid propylene and liquid benzene through alkylation reaction and transalkylation reaction. Due to the fluctuations in indicators such as propane and ethane in the propylene raw material, it is easy to cause fluctuations in the benzene column pressure, resulting in fluctuations in the system in the cumene process, and thus the cumene production system cannot operate in a long-term manner.

[0004] Therefore, it is necessary to provide a benzene column pressure control system, a cumene production system and a method thereof to solve the above problems. Summary of the Invention

[0005] In view of the above disadvantages of the prior art, the present invention provides a benzene column pressure control system, a cumene production system and a method thereof to improve the problem of benzene column pressure fluctuations.

[0006] To achieve the above and other related purposes, the present invention provides a benzene column pressure control system, which includes: a benzene column, a reflux drum and a disturbance device. The reflux drum is arranged at the top of the benzene column and is communicated with the benzene column; the disturbance device includes a gas pipeline and a spraying device. The spraying device is installed at the bottom of the reflux drum. One end of the gas pipeline is communicated with the spraying device, and the other end is communicated with disturbance gas; the disturbance gas enters the spraying device through the gas pipeline and is sprayed into the reflux drum by the spraying device, so that the light hydrocarbon components in the system are discharged along with the disturbance gas.

[0007] In an example of the present invention, the spraying device includes a spraying base and a plurality of nozzles. The spraying base is fixed at the bottom of the reflux drum and is communicated with the gas pipeline. The spraying base extends along the length direction of the reflux drum, and the plurality of nozzles are arranged at intervals and staggered on both sides of the spraying base along the extension direction of the spraying base.

[0008] In an example of the present invention, the nozzles are installed obliquely upward on the spraying base, and the included angle between the outlet direction of the nozzles and the spraying base is θ, and θ satisfies 25° ≤ θ ≤ 60°.

[0009] In an example of the present invention, the nozzle includes a main body portion and a connecting portion extending radially outward along the main body portion. The connecting portion is fixed on the injection base. A reinforcing portion is provided on the inner wall of the nozzle facing the connecting portion, and the size of the reinforcing portion in the radial direction of the nozzle gradually increases from the main body portion to the connecting portion.

[0010] In an example of the present invention, a top condenser is provided at the top of the benzene column, and the top condenser is connected to the reflux drum and the benzene column respectively through a material conveying pipeline.

[0011] In an example of the present invention, a discharge port is provided at the top of the reflux drum, a discharge pipeline is connected to the discharge port, and a first valve is provided on the discharge pipeline.

[0012] In an example of the present invention, a second valve for controlling the disturbance gas is provided on the gas pipeline.

[0013] In an example of the present invention, the disturbance gas is nitrogen.

[0014] On the other hand, the present invention provides a cumene production system, which includes a propylene treatment device, an alkylation reactor, a benzene treatment device, and the benzene column pressure control system described in any one of the above. The propylene treatment device is connected to the alkylation reactor, the alkylation reactor is connected to the benzene column in the benzene column pressure control system, and the benzene treatment device is connected to the benzene column.

[0015] The present invention also provides a method for producing cumene, and the production method is carried out by using the production system described above in the present invention.

[0016] The benzene column pressure control system of the present invention installs an injection device at the bottom of the reflux drum of the benzene column, adds a gas pipeline to the control system, connects the gas pipeline to the injection device at the bottom of the reflux drum, allows the disturbance gas to enter the injection device through the gas pipeline, and then is injected into the reflux drum by the injection device, causing the material in the reflux drum to bubble, increasing the disturbance of the material, destroying the relative state of the light hydrocarbon components, so as to effectively discharge the light hydrocarbons in the system together with the disturbance gas, reduce the accumulation of light hydrocarbon components in the system, and thus ensure the stability of the benzene column pressure.

[0017] The cumene production system of the present invention includes the above-mentioned benzene column pressure control system, which can adapt to propylene with different purities and ensure the safe and stable operation of the benzene column pressure; and the production system of the present invention can reduce the setting of the depropanizer column, deethanizer column, and benzene refining column, greatly reducing the investment cost of the cumene production device, while ensuring the safe operation of the equipment. Using the cumene production system of the present invention to produce cumene can reduce the production cost while ensuring the production efficiency of cumene. Description of the Drawings

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a schematic diagram of the benzene column pressure control system of the present invention applied to an isopropylbenzene production system in an embodiment;

[0020] Figure 2 It is a top view schematic diagram of the reflux drum and the injection device of the benzene column pressure control system of the present invention in an embodiment;

[0021] Figure 3 It is a side view schematic diagram of the reflux drum and the injection device of the benzene column pressure control system of the present invention in an embodiment;

[0022] Figure 4 It is a schematic diagram of the structure of the nozzle of the benzene column pressure control system of the present invention in an embodiment;

[0023] Figure 5 For Figure 4 partial sectional view schematic diagram;

[0024] Figure 6 It is a pressure change curve graph of the benzene column and the reflux drum in the isopropylbenzene production system of the present invention.

[0025] Element number description

[0026] 10. Benzene column pressure control system; 11. Benzene column; 111. Second heater; 12. Reflux drum; 121. First discharge pipeline; 122. First valve; 123. Second discharge pipeline; 124. First circulation pump; 125. Third discharge pipeline; 126. Second circulation pump; 13. Gas pipeline; 131. Second valve; 14. Injection device; 141. Injection base; 142. Nozzle; 1421. Main body part; 1422. Connection part; 1423. Reinforcement part; 15. Top condenser; 151. Material conveying pipeline; 16. Third circulation pump; 17. Non-aromatic to storage tank; 20. Alkylation reactor; 21. First heater; 22. Condenser; 30. Propylene treatment device; 40. Benzene treatment device; S1. Disturbance gas; S2. Propylene; S3. Benzene; S4. Alkylation material; S5. Waste water. Detailed implementation manners

[0027] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0028] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the layout type of its components may also be more complex.

[0029] In the following description, a large number of details are explored to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.

[0030] In the cumene production unit, the main purpose of the benzene column is to separate benzene and cumene. In addition, it also plays the role of separating non-aromatics, propane, and water. Propane comes from the propylene raw material and is mainly discharged at the top of the benzene column. Most of the propane is discharged in the form of non-condensable gas, and the remaining propane is dissolved in the condensate. If the content of components such as propane and ethane in the propylene raw material is too high, the proportion dissolved in the system will increase, resulting in the accumulation of light hydrocarbon components in the system and incomplete discharge, thus causing fluctuations in the pressure of the benzene column.

[0031] Based on this, the present invention provides a benzene column pressure control system, a cumene production system including the benzene column pressure control system, and a cumene production method. By adding a disturbance device to the benzene column pressure control system, the injection device in the disturbance device is used to inject disturbance gas into the reflux drum, increasing the disturbance of the materials in the reflux drum, destroying the relative state of the light hydrocarbon components, and effectively discharging the light hydrocarbon components out of the system together with the disturbance gas, reducing the accumulation of light hydrocarbon components in the system.

[0032] Please refer to Figure 1 , in the first aspect of the present invention, a benzene column pressure control system 10 is provided. The control system includes a benzene column 11, a reflux drum 12, and a disturbance device.

[0033] The top of the benzene tower 11 contains gaseous non-condensable steam (propane, etc.), and the reflux tank 12 is arranged at the top of the benzene tower 11 and communicated with the benzene tower 11. The reflux tank 12 is used to separate the gas-liquid mixture entering from the benzene tower 11 into gas-liquid phases. A tower top condenser 15 is arranged between the benzene tower 11 and the reflux tank 12, one end of the tower top condenser 15 is communicated with the top of the benzene tower 11 through a material conveying pipeline 151, and the other end is communicated with the reflux tank 12 through a material conveying pipeline 151. The gas at the top of the benzene tower 11 is cooled by the tower top condenser 15 to generate a gas-liquid mixture, which enters the reflux tank 12 for gas-liquid phase separation.

[0034] Furthermore, a first discharge port is provided at the top of the reflux tank 12, a first discharge port is connected to a first discharge pipe 121, a first valve 122 is provided on the first discharge pipe 121, and the first valve 122 is used to control the discharge flow rate; a second discharge port and a third discharge port are provided at the bottom of the reflux tank 12, the second discharge port is arranged on a side close to the benzene tower 11, and the third discharge port is arranged on a side away from the benzene tower 11, the second discharge port is connected to a second discharge pipe 123, the second discharge pipe 123 is connected to a first circulation pump 124, and the second discharge port is used to discharge non-aromatic hydrocarbons after gas-liquid separation; the third discharge port is connected to a third discharge pipe 125, and the end of the third discharge pipe 125 away from the third discharge port is connected to a second circulation pump 126, and the waste water S5 after gas-liquid separation is discharged through the third discharge pipe 125 and enters the second circulation pump 126 for recycling.

[0035] Since incomplete discharge of light components from the top of the benzene tower 11 will cause pressure fluctuations in the benzene tower, the present application adds a disturbance device to the benzene tower pressure control system 10 to assist in discharging the light components in the system.

[0036] See also Figure 1 In one embodiment, the disturbance device includes a gas pipeline 13 and an injection device 14. The injection device 14 is installed at the bottom of the reflux tank 12. The gas pipeline 13 is set on one side of the reflux tank 12. One end of the gas pipeline 13 is connected to the injection device 14, and the other end is connected to the disturbance gas S1. The above-mentioned disturbance gas S1 enters the injection device 14 through the gas pipeline 13, and is injected into the reflux tank 12 by the injection device 14, so that the material in the reflux tank 12 is bubbled to increase the disturbance of the material and destroy the relative state of the light hydrocarbon components, thereby effectively discharging the light hydrocarbon components in the system with the disturbance gas and reducing the accumulation of light hydrocarbon components in the system. Furthermore, a second valve 131 for adjusting the flow of the disturbance gas is provided on the gas pipeline 13.

[0037] The disturbance gas S1 is a stable gas that does not undergo any chemical reaction with the components in the system and does not affect the state of the system components. For example, it can be nitrogen or an inert gas such as argon, helium, etc.

[0038] Please refer to Figure 1 and Figure 2 In one embodiment, the injection device 14 includes an injection base 141 and a plurality of nozzles 142. Among them, the injection base 141 is fixed to the bottom of the reflux tank 12 and extends along the axial direction of the reflux tank 12. The interior of the injection base 141 is a hollow structure, and the injection base 141 communicates with the gas pipeline 13. The plurality of nozzles 142 are spaced apart on both sides of the injection base 141 along the extending direction of the injection base 141, and the nozzles 142 on both sides are staggeredly arranged. In this way, the disturbing gas S1 in the gas pipeline 13 will first enter the injection base 141, and then enter each nozzle 142 from the injection base 141, and be ejected through the nozzle 142 into the interior of the reflux tank 12. The plurality of nozzles 142 are spaced apart on both sides of the injection base 141, which can disturb each position in the reflux tank 12, so as to more greatly destroy the relative state of the materials in the reflux tank 12, so as to discharge more light components with the disturbing gas.

[0039] Please refer to Figure 2 and Figure 3 Furthermore, the nozzles 142 are installed obliquely upward, and the included angle between the outlet direction of the nozzles 142 and the installation surface of the injection base 141 is θ, and the value of θ should satisfy 25° ≤ θ ≤ 60°. For example, θ can be 25°, 45°, or 60°, etc. Installing the nozzles 142 within this angle range can make the ejected gas collide with the inner walls on both sides of the reflux tank 12 to increase the disturbing effect of the gas.

[0040] Please refer to Figure 4 and Figure 5 The above nozzles 142 can adopt any structure that can eject gas. In one embodiment, the nozzle 142 includes a main body portion 1421 and a connecting portion 1422. The main body portion 1421 is a hollow cylindrical structure, and the connecting portion 1422 extends radially outward along the main body portion 1421. The nozzle 142 is fixed to the injection base 141 through the connecting portion 1422. Further, a reinforcing portion 1423 is provided on the inner wall of the nozzle 142 to increase the strength of the inlet end of the nozzle 142. The reinforcing portion 1423 extends from one end of the main body portion 1421 facing the connecting portion 1422 to the connecting portion 1422, and the dimension of the reinforcing portion 1423 in the radial direction of the nozzle 142 gradually decreases from the connecting portion 1422 to the main body portion 1421. That is, the inner diameter of the nozzle 142 remains unchanged, and the side of the reinforcing portion 1423 facing away from the hollow structure is gradually inclined from the connecting portion 1422 to the main body portion 1421, and the inclination angle should not be too large. In this embodiment, the inclination angle is 3°.

[0041] Please refer to Figure 5, the size of the nozzle 142 can be set according to actual needs (the flow rate of the disturbing gas required by the system). In this embodiment, the overall height H of the nozzle 142 is 190 to 200 mm. For example, it can be 196 mm, and the inner diameter d of the nozzle 142 is 60 to 100 mm. For example, it can be 80 mm.

[0042] Please refer to Figure 1 , the benzene column pressure control system 10 of the present invention adds a disturbing device, uses the gas pipeline 13 to send the disturbing gas S1 into the spraying device 14, and then sprays it into the reflux tank 12 through the spraying device 14, so that the materials in the reflux tank 12 are bubbled, increasing the disturbance of the materials, destroying the relative state of the light hydrocarbon components, and thus effectively discharging the light hydrocarbons in the system together with the disturbing gas S1, reducing the accumulation of light hydrocarbon components in the system, and thus ensuring the stability of the pressure of the benzene column 11. The benzene column pressure control system 10 of the present application can be used in the production of isopropylbenzene and also in other alkylation reactions.

[0043] Please refer to Figure 1 , the second aspect of the present invention provides a production system for isopropylbenzene. The production system includes the above-mentioned benzene column pressure control system 10. Since the benzene column pressure control system 10 enables the production system for isopropylbenzene to adapt to propylene S2 of different purities and ensures the safe and stable operation of the benzene column pressure, the requirements for the raw material propylene are greatly reduced, thereby reducing the production cost.

[0044] The above-mentioned isopropylbenzene production system includes a benzene column pressure control system 10, an alkylation reactor 20, a propylene treatment device 30, and a benzene treatment device 40. Among them, the benzene column pressure control system 10 includes a benzene column 11, a reflux tank 12, and a disturbing device. The specific structures of the components of the benzene column pressure control system 10 can be seen in the above detailed description and will not be elaborated here. The alkylation reactor 20 and the propylene treatment device 30 are arranged on one side of the benzene column 11. And the propylene treatment device 30 is arranged at the front end of the alkylation reactor 20 and is communicated with the alkylation reactor 20. The raw material propylene S2 first enters the propylene treatment device 30 for impurity removal and then enters the alkylation reactor 20 to participate in the alkylation reaction; the benzene treatment device 40 is arranged on the other side of the benzene column 11 and is communicated with the benzene column 11. The raw material benzene S3 enters the benzene column 11 after preliminary impurity removal by the benzene treatment device 40, and then enters the alkylation reactor 20 after separation and purification by the benzene column 11 to carry out an alkylation reaction with propylene S2; the alkylation material S4 in the alkylation reactor 20 enters the benzene column 11 for separation.

[0045] Please refer to Figure 1, in one embodiment, the alkylation reactor 20 is provided with a feed inlet at the top and a discharge outlet at the bottom. The propylene S2 processed by the propylene treatment device 30 enters the alkylation reactor 20 through the feed inlet. One side of the benzene tower 11 is provided with an alkylation material S4 inlet, and the other side is provided with a benzene feed inlet. The benzene S3 enters the benzene tower 11 through the benzene feed inlet after preliminary treatment, and is discharged from the side line after rectification in the benzene tower 11 and enters the alkylation reactor 20 to react with the propylene S2; further, a first heater 21 is provided on one side of the alkylation reactor 20 near the feed inlet, and a condenser 22 is provided on the side near the discharge outlet. The first heater 21 is used to heat the materials in the alkylation reactor 20 to provide a suitable reaction temperature for the alkylation reaction; the condenser 22 is used to cool the reaction products. The alkylated material S4 after the alkylation reaction is discharged from the discharge outlet at the bottom of the alkylation reactor 20, enters the benzene tower 11 through the alkylation material inlet, and is separated by the benzene tower 11 to obtain cumene. Further, a second heater 111 is provided on one side of the benzene tower 11 near the alkylation material inlet, which can provide a suitable temperature for the separation and purification of the materials in the benzene tower 11; a third circulation pump 16 and a non-aromatic hydrocarbon to storage tank 17 are also provided on one side of the benzene tower 11. The third circulation pump 16 is used to circulate the recycled benzene discharged from the side line of the benzene tower 11, and the non-aromatic hydrocarbon to storage tank 17 is used to collect the non-aromatic hydrocarbons discharged from the benzene tower 11 and the third circulation pump 16.

[0046] It should be noted that the structures not detailed in the above cumene production system can be set with reference to the conventional structures in the art and will not be elaborated here.

[0047] Please refer to Figure 1 , compared with the prior art, the cumene production system of the present application reduces the separation towers such as the depropanizer tower, deethanizer tower, and benzene refining tower in the conventional system, greatly reducing the investment and operating costs of production equipment; however, if only the depropanizer tower, deethanizer tower, and benzene refining tower are removed without other improvements, the requirements for the propylene S2 raw material will also increase significantly; the increase in the requirements for the propylene S2 raw material means an increase in processing costs and a decrease in the selectivity of the propylene raw material (currently, the propylene principle basically depends on the polymer-grade propylene from ethylene plants). For the current refining and chemical integration device, the fluctuations in the indicators such as propane and ethane in the propylene S2 raw material will cause fluctuations in the pressure of the benzene tower, and then cause fluctuations in the cumene production system, affecting the long-term operation. Therefore, the benzene tower pressure control system 10 of the present application can well solve the problem of pressure fluctuations in the benzene tower 11, and can reduce the purity requirement of the propylene raw material from 99.4789% to 94% to 96%, and increase the propane content in the propylene raw material from 0.5184% to 4% to 6%.

[0048] The third aspect of the present invention provides a method for producing cumene, which is carried out in the cumene production system described above.

[0049] Please refer to Figure 1 . The specific process is as follows. The raw material propylene S2 enters the alkylation reactor 20 after being purified by the propylene treatment device 30. The raw material benzene S3 enters the benzene column 11 after being preliminarily treated by the benzene treatment device 40, is dehydrated, and then discharged from the side line and enters the alkylation reactor 20, and the recycled benzene is discharged from the side line of the benzene column 11 and enters the alkylation reactor 20 for reaction; the alkylated material S4 after the reaction enters the benzene column 11 from the bottom of the benzene column 11 for separation; the gas at the top of the benzene column 11 enters the top condenser 15 for condensation. At the same time, the second valve 131 on the gas pipeline 13 is in an open state, so that the disturbance gas S1 enters the injection device 14 through the gas pipeline 13, is injected into the reflux drum 12 by the injection device 14, and the non-condensable gas is discharged from the reflux drum 12 at the top of the benzene column 11 by using the disturbance gas S1, preventing excessive accumulation of light hydrocarbon components in the reflux drum 12 and causing pressure fluctuations in the benzene column. During the production process of cumene, the pressures of the benzene column 11 and the reflux drum 12 are detected in real time, and the test results are shown in Figure 6 . From Figure 6 , it can be seen that before the improvement, the pressure fluctuations of the benzene column 11 and the reflux drum 12 were significantly unstable. After the improvement, the pressure fluctuations of the benzene column 11 and the reflux drum 12 were extremely small, indicating that the benzene column pressure control system 10 of the present invention can well control the tower pressure to meet the requirements of raw materials with different purities.

[0050] The benzene column pressure control system of the present invention installs an injection device at the bottom of the reflux drum and adds a gas pipeline, connects the gas pipeline with the injection device at the bottom of the reflux drum, allows the disturbance gas to enter the injection device through the gas pipeline, and then is injected into the reflux drum by the injection device, so that the material in the reflux drum undergoes bubbling, increasing the disturbance of the material and destroying the relative state of the light hydrocarbon components, thereby effectively discharging the light hydrocarbon components in the system together with the disturbance gas, reducing the accumulation of light hydrocarbon components in the system, and thus ensuring the stability of the benzene column pressure. In addition, since the cumene production system includes the benzene column pressure control system, it can adapt to propylene with different purities and ensure the safe and stable operation of the benzene column pressure; and this production system can reduce the settings of the depropanizer, deethanizer, and benzene refining column, greatly reducing the investment cost of the cumene production device, while ensuring the safe operation of the equipment. Using the cumene production system of the present invention to produce cumene can reduce the production cost while ensuring the production efficiency of cumene. Therefore, the present invention effectively overcomes some practical problems in the prior art and thus has high utilization value and practical significance.

[0051] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A benzene tower pressure control system, characterized in that, include: Benzene Tower; A reflux tank is disposed at the top of the benzene tower and is connected to the benzene tower; and A disturbance device, comprising a gas pipeline and an injection device, wherein the injection device is installed at the bottom of the reflux tank, one end of the gas pipeline is connected to the injection device, and the other end is connected to the disturbance gas; Wherein, the spraying device comprises a spraying base and a plurality of nozzles, the spraying base is fixed at the bottom of the reflux tank and is connected to the gas pipeline, the spraying base extends along the length direction of the reflux tank, and the plurality of nozzles are staggered and arranged at intervals on both sides of the spraying base along the extension direction of the spraying base; The disturbing gas enters the injection device through the gas pipeline and is injected into the reflux tank by the injection device, so that the material in the reflux tank is bubbled, the disturbance of the material is increased, and the relative state of the light hydrocarbon components is destroyed, so that the light hydrocarbon components in the system are discharged along with the disturbing gas.

2. The benzene tower pressure control system according to claim 1, characterized in that: The nozzle is installed on the spray base with an angle upward, and the angle between the outlet direction of the nozzle and the spray base is θ, and θ satisfies 25°≤θ≤60°.

3. The benzene tower pressure control system according to claim 1, characterized in that: The nozzle includes a main body and a connecting portion extending radially outward from the main body, the connecting portion is fixed on the injection base, and a reinforcement portion is provided on the inner wall of the nozzle toward the connecting portion, and the size of the reinforcement portion along the radial direction of the nozzle gradually increases from the main body to the connecting portion.

4. The benzene tower pressure control system according to claim 1, characterized in that: A top condenser is provided at the top of the benzene tower, and the top condenser is respectively connected with the reflux tank and the benzene tower through a material conveying pipeline.

5. The benzene tower pressure control system according to claim 1, characterized in that: A discharge port is provided at the top of the reflux tank, a discharge pipe is connected to the discharge port, and a first valve is provided on the discharge pipe.

6. The benzene tower pressure control system according to claim 1, characterized in that: The gas pipeline is provided with a second valve for controlling the disturbing gas.

7. The benzene tower pressure control system according to claim 1, characterized in that: The disturbance gas is nitrogen.

8. A system for producing cumene, characterized in that: It comprises a propylene processing device, an alkylation reactor, a benzene processing device and a benzene tower pressure control system according to any one of claims 1 to 7, wherein the propylene processing device is connected to the alkylation reactor, the alkylation reactor is connected to the benzene tower in the benzene tower pressure control system, and the benzene processing device is connected to the benzene tower.

9. A method for producing cumene, characterized in that: The method is carried out using the production system according to claim 8.

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