Anti-coking herringbone baffle at bottom of crude oil catalytic cracking fractionating tower

Abstract

The utility model belongs to the technical field of fractionating tower equipment, and particularly relates to an anti-coking herringbone baffle plate at the bottom of a crude oil catalytic cracking fractionating tower, which comprises a support plate rib plate, a support plate and a baffle plate, wherein the baffle plate is a herringbone baffle plate, and the inner included angle of the herringbone baffle plate is 140-160 degrees; the supporting plate and the baffle are the same in shape, the supporting plate is connected to the lower end of the baffle, the supporting plate rib plate is a rectangular plate, and the supporting plate rib plate is vertically connected to the inner angle bisector of the supporting plate. The herringbone baffle can effectively cool rising oil gas, prevent the bottom of the fractionating tower from being coked, and prolong the service life of equipment; the production efficiency is improved, and production interruption caused by coking is reduced; the safety is enhanced, and the safety risk caused by coking is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of fractionation tower equipment, and in particular relates to a coking prevention herringbone baffle at the bottom of a crude oil catalytic cracking fractionation tower. Background Art

[0002] In the process of catalytic cracking to produce olefins, the fractionating tower is a key equipment for separating mixtures with different boiling points. In the fractionating tower, the desuperheating section annular disc baffle is an internal structure used to improve gas-liquid contact and heat transfer efficiency. It is located in the desuperheating section of the fractionating tower, which is the first part that the oil and gas pass through after entering the fractionating tower. In the prior art, such as application numbers 202122353188 and 201720389663, although it involves setting a herringbone baffle in the fractionating tower to prevent coking, the fractionating tower is a conventional catalytic cracking unit fractionating tower, and its operating temperature is often below 400°C. At the same time, the commonly used herringbone baffle top angle is generally set to 120° (Teng Binqiang, Application of Herringbone Baffles in Catalytic Fractionating Towers, 2004).

[0003] Furthermore, commonly used herringbone baffles can reach lengths up to 3000mm, are prone to deformation at high temperatures, and have poor overall bending strength. Because the reaction temperature of the crude oil catalytic cracking process to produce olefins (approximately 700°C) is much higher than that of traditional catalytic cracking, the oil slurry system entering the fractionating tower has a high viscosity and is prone to coking, which increases the tower bottom temperature and affects production efficiency. Severe coking can cause the crude oil catalytic cracking unit to shut down, hindering long-term operation. Utility Model Content

[0004] The purpose of the utility model is to provide an anti-coking herringbone baffle at the bottom of a crude oil catalytic cracking distillation tower. A herringbone baffle with a specific structure is arranged at the bottom of the distillation tower, which increases the contact area between the gas and liquid phases, improves the mass transfer efficiency, and effectively reduces the risk of coking at the bottom of the distillation tower, thereby ensuring a significant increase in product yield.

[0005] In order to achieve the above purpose, the present invention is implemented through the following technical solutions:

[0006] The utility model provides an anti-coking herringbone baffle at the bottom of a crude oil catalytic cracking fractionation tower, comprising a support plate rib, a support plate and a baffle; wherein the baffle is a herringbone baffle, and the inner angle of the herringbone baffle is 140°-160°; the support plate and the baffle have the same shape, the support plate is connected to the lower end of the baffle, the support plate rib is a rectangular plate, and the support plate rib is vertically connected to the inner angle bisector of the support plate.

[0007] As a further technical solution, it also includes a rib plate, which is a rectangular plate and includes a first rib plate and a second rib plate.

[0008] As a further technical solution, both ends of the baffle are provided with folded edges, and the folded edges of the baffle are directed vertically upward.

[0009] As a further technical solution, the two folded edges of the baffle are respectively connected to the first rib plate and the second rib plate.

[0010] As a further technical solution, the inner bending radius of the folded edge of the baffle is the same as the thickness of the baffle.

[0011] As a further technical solution, the support plate is a herringbone support plate, and the inner angle of the herringbone support plate is equal to the inner angle of the herringbone baffle.

[0012] As a further technical solution, both ends of the support plate are provided with folded edges, and the folded edges of the support plate are directed vertically downward.

[0013] As a further technical solution, the two folded edges of the support plate are respectively connected to the first rib plate and the second rib plate.

[0014] As a further technical solution, the inner bending radius of the folded edge of the support plate is the same as the thickness of the support plate.

[0015] As a further technical solution, the connection is welding or movable connection.

[0016] The beneficial effects of the above embodiments of the present invention are as follows:

[0017] (1) The anti-coking herringbone baffle provided by the utility model can be applied to the working conditions of the crude oil catalytic cracking fractionation tower with higher reaction temperature. The inner angle of the herringbone baffle is 140°-160°, which can increase the gas-liquid contact area, thereby improving the gas-liquid heat transfer and mass transfer efficiency; at the same time, it can effectively wash away the catalyst powder entrained in the oil and gas, prevent the catalyst from accumulating on the tower plate, and keep the tower plate clean and efficient.

[0018] (2) The anti-coking herringbone baffle provided by the present invention is provided with a support plate and a rib plate at the bottom and both ends, respectively, which can enhance the bending strength of the herringbone baffle; both ends of the herringbone baffle are provided with folding edges, and the inner bending radius of the folding edge is the same as the thickness of the herringbone baffle, which can further enhance the bending strength of the herringbone baffle.

[0019] (3) The anti-coking herringbone baffle provided by the utility model can be predicted and optimized by simulation tools such as fluid dynamics (CFD) to achieve the best design. It has a simple structure and is easy to install and maintain. It is suitable for a variety of different operating conditions and materials and has good versatility. Compared with other types of tower plates, the design of the herringbone baffle can reduce the pressure drop in the tower, thereby reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0021] Figure 1 This is a herringbone baffle structure of the utility model;

[0022] Among them, the support plate rib plate (1), the support plate (2), the rib plate (3), and the baffle (4);

[0023] The diagrams are for illustrative purposes only. DETAILED DESCRIPTION

[0024] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0025] The design of the anti-coking herringbone baffle provided by the utility model is based on the optimization of the structure of the herringbone baffle by simulation tools such as fluid dynamics (CFD). The optimization process is as follows:

[0026] (1) Determine the simulation purpose and requirements:

[0027] In the CFD simulation software simulation, by changing the angle of the herringbone baffles, better cooling of the distillation tower bottom can be achieved, further preventing the risk of coking.

[0028] (2) Model building:

[0029] Establish a model in CFD simulation software, including geometric modeling, material property definition, temperature input, etc.

[0030] (3) Set simulation parameters:

[0031] Parameters were set according to simulation requirements, and the angles were set to 100°-120°, 120°-140°, and 140°-160° for comparison and selection.

[0032] (4) Perform simulation calculations:

[0033] Set the inlet temperature at the bottom of the distillation tower to 400°C and run the simulation under three different herringbone baffle angles. The software will perform calculations based on the input parameters and model.

[0034] (5) Result analysis:

[0035] Analysis of simulation results shows that the temperatures of the upper side of the chevron-shaped baffle after cooling were 358°C, 343°C, and 331°C, respectively, at three angle designs: 100°-120°, 120°-140°, and 140°-160°. Therefore, it was determined that the chevron-shaped baffle angle should be increased to 140°-160°.

[0036] Example 1

[0037] In a typical embodiment of the present invention, Figure 1 As shown, a herringbone baffle for preventing coking at the bottom of a crude oil catalytic cracking fractionation tower is provided, comprising a support plate rib (1), a support plate (2) and a baffle (4); wherein the baffle (4) is a herringbone baffle, and the inner angle of the baffle (4) is 140°-160°; setting the inner angle of the baffle (4) to 140°-160° will further increase the gas-liquid contact area, thereby improving the gas-liquid heat transfer and mass transfer efficiency; at the same time, it can effectively wash away catalyst powder entrained in the oil and gas, prevent the catalyst from accumulating on the tower plate, and maintain the cleanliness and efficiency of the tower plate.

[0038] The support plate (2) and the baffle (4) have the same shape, that is, the support plate (2) is a herringbone support plate, and the inner angle of the herringbone support plate is equal to the inner angle of the herringbone baffle; the support plate (2) is connected to the lower end of the baffle (4). This arrangement can enhance the tightness of the connection between the support plate (2) and the baffle (4). The support plate (2) is used to enhance the rigidity and strength of the baffle (4), thereby enhancing the bending strength of the baffle (4) at high temperatures.

[0039] The support plate rib (1) is a rectangular plate, and the support plate rib (1) is vertically connected to the inner angle bisector of the support plate (2); the support plate rib (1) is used to share the force of the support plate (2) and transfer and disperse the pressure to ensure that the force-bearing area of ​​the support plate (2) does not bear excessive load, thereby further enhancing the bending strength of the overall structure.

[0040] The invention also includes a rib plate (3), wherein the rib plate (3) is a rectangular plate and includes a first rib plate and a second rib plate. The width of the support plate rib plate (1) is the same as that of the rib plate (3). The rib plate (3) is used to enhance the rigidity and strength of the support plate (2) and the baffle (4), thereby further enhancing the bending strength of the overall structure.

[0041] The baffle (4) is provided with folded edges at both ends, the folded edges of the baffle (4) are vertically upward, and the inner radius of the folded edges of the baffle (4) is the same as the thickness of the baffle (4). The two folded edges of the baffle (4) are connected to the first rib plate and the second rib plate respectively. This connection method can improve the rigidity and strength of the baffle (4), enhance the uniformity of the force applied to the baffle (4), and further improve the bending strength of the baffle (4) at high temperatures.

[0042] The support plate (3) is provided with folded edges at both ends, the folded edges of the support plate (3) are oriented vertically downward, and the inner bending radius of the folded edges of the support plate (3) is the same as the thickness of the support plate. The two folded edges of the support plate (3) are connected to the first rib plate and the second rib plate respectively. This connection method can improve the rigidity and strength of the support plate (3), enhance the uniformity of the force applied to the support plate (3), and further improve the bending strength of the support plate (3).

[0043] The connection described in the utility model is welding or movable connection. This connection mode is not only simple to construct, but also can enhance the connection strength of each component.

[0044] The utility model discloses a method for installing an anti-coking herringbone baffle at the bottom of a crude oil catalytic cracking fractionation tower, comprising the following steps:

[0045] Step 1. The two ends of the support plate (2) and the baffle (4) are respectively formed into folded edges, and the inner radius of the folded edges is the same as the thickness of the support plate (2) and the baffle (4);

[0046] Step 2. Place the support plate (2) below the baffle (4) and vertically connect the support plate rib (1) to the inner angle bisector of the support plate (2);

[0047] Step 3. Connect the two folded edges of the support plate (2) and the baffle (4) to the rib plate (3) respectively.

[0048] The anti-coking herringbone baffle at the bottom of the crude oil catalytic cracking fractionation tower in the utility model has been successfully installed at the bottom of the fractionation tower in the crude oil catalytic cracking unit. The oil slurry in the oil slurry pool is transported to the top of the herringbone baffle through an oil slurry pump. In actual equipment operation, it is found that after the herringbone baffle structure at the bottom of the crude oil catalytic cracking fractionation tower is modified to 140°-160°, the problem of clogging of the filter at the bottom of the fractionation tower no longer occurs, the coking problem is significantly improved, and the dry gas component distilled from the fractionation tower is increased by 3% compared with before the modification, which effectively reduces the risk of coking at the bottom of the fractionation tower and significantly improves the product yield.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An anti-coking herringbone baffle at the bottom of a crude oil catalytic cracking fractionation tower, characterized in that: It includes a support plate rib, a support plate and a baffle; wherein, the baffle is a herringbone baffle, and the inner angle of the herringbone baffle is 140°-160°; the support plate and the baffle have the same shape, the support plate is connected to the lower end of the baffle, the support plate rib is a rectangular plate, and the support plate rib is vertically connected to the inner angle bisector of the support plate.

2. The anti-coking herringbone baffle at the bottom of the crude oil catalytic cracking fractionation tower according to claim 1, characterized in that: It also includes a rib plate, which is a rectangular plate and includes a first rib plate and a second rib plate.

3. The anti-coking herringbone baffle at the bottom of the crude oil catalytic cracking fractionation tower according to claim 2, characterized in that: Both ends of the baffle are provided with folded edges, and the folded edges of the baffle are vertically upward.

4. The anti-coking herringbone baffle at the bottom of the crude oil catalytic cracking fractionation tower according to claim 3, characterized in that: The two folded edges of the baffle are connected to the first rib plate and the second rib plate respectively.

5. The anti-coking herringbone baffle at the bottom of the crude oil catalytic cracking fractionation tower according to claim 3, characterized in that: The inner bending radius of the folded edge of the baffle is the same as the thickness of the baffle.

6. The anti-coking herringbone baffle at the bottom of the crude oil catalytic cracking fractionation tower according to claim 1, characterized in that: The support plate is a herringbone support plate, and the inner angle of the herringbone support plate is equal to the inner angle of the herringbone baffle.

7. The anti-coking herringbone baffle at the bottom of the crude oil catalytic cracking fractionation tower according to claim 2, characterized in that: Folding edges are provided at both ends of the support plate, and the folding direction of the support plate is vertically downward.

8. The anti-coking herringbone baffle at the bottom of the crude oil catalytic cracking fractionation tower according to claim 7, characterized in that: The two folded edges of the support plate are connected to the first rib plate and the second rib plate respectively.

9. The anti-coking herringbone baffle at the bottom of the crude oil catalytic cracking fractionation tower according to claim 7, characterized in that: The inner bending radius of the folded edge of the support plate is the same as the thickness of the support plate.

10. The anti-coking herringbone baffle at the bottom of a crude oil catalytic cracking fractionation tower according to any one of claims 1, 4 or 8, characterized in that: The connection is welding or movable connection.

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