Static mixing device for large-scale crude oil electric desalting system

Abstract

The utility model discloses a static mixing equipment for large scale crude oil electric desalting system, including series connection setting injection injection system and static mixing system of injection agent, injection injection system of injection agent is located equipment inlet end, and it includes the venturi nozzle arrangement in equipment pipeline center area, and the injection agent injection port direction of venturi nozzle is set with the process medium flow direction reverse direction. The application can directly inject water, chemical reagent and the like injection agent into the center part of mixing equipment pipeline through the venturi nozzle structure design effect, and the flow direction of water, chemical reagent injection and crude oil flow direction are reverse, so as to can carry out the premixing of high penetration rate, after reverse premixing, multiphase fluid flows through static mixing system again, carries out left -handed, right -handed, static mixing process such as shunt, realizes the full mixing of crude oil, water, chemical reagent.

Description

Technical Field

[0001] This utility model relates to the field of petroleum processing equipment technology, specifically to a static mixing device for a large-scale crude oil electrostatic desalting system. Background Technology

[0002] The modern petrochemical industry typically uses electrostatic desalting and dehydration (ESD) processes to desalt and dehydrate crude oil. The basic process is as follows: crude oil is injected with a demulsifier to break the oil-water emulsion; water is then injected to dissolve the inorganic salts in the crude oil; finally, oil and water are separated in the ESD tank, achieving the purpose of crude oil desalting and dehydration.

[0003] The effective removal of water and inorganic salts from crude oil largely depends on the degree of mixing between the crude oil and the wash water and demulsifier. The desalting and dehydration process requires thorough mixing of crude oil, wash water, and demulsifier to ensure that the oil-water emulsion film in the crude oil is destroyed, the oil and water phases can be effectively separated, and the inorganic salts in the crude oil are fully dissolved in the wash water, providing favorable conditions for the next step of electro-desalting and dehydration.

[0004] One of the development trends in the petrochemical industry is the increasing scale of crude oil refining. Currently, my country has built several large-scale refining bases with a capacity of tens of millions of tons, and several more are under planning and preparation. This necessitates further scaling up of crude oil refining equipment. Traditional crude oil electrostatic desalting systems often use water and injectable agents injected through the sidewall of the crude oil pipeline, followed by mixing in a static mixer. Static mixers typically employ the Kenneth type or its improved versions for mixing crude oil, water, and injectable agents. When the crude oil pipeline diameter is small, these mixers offer advantages such as simple structure and good mixing effect. However, with the increasing scale of crude oil refining, the crude oil pipelines of crude oil electrostatic desalting units have changed from the early small and medium-sized pipelines such as DN50, DN100, and DN200 to DN500, DN600, and even larger diameters. Furthermore, due to the low flow velocity of crude oil within the pipelines and the thick laminar inner layer, the sidewall injection method for water and chemical agents is not ideal for mixing in large-diameter pipelines. This necessitates longer flow times and larger, longer static mixers. However, manufacturing and installing larger, longer static mixers is extremely difficult, and the limited space required for electrostatic desalting units makes installation and operation highly challenging. Therefore, for large-scale crude oil electrostatic desalting equipment, it is necessary to develop new mixing equipment specifically designed to achieve high efficiency in the mixing process and miniaturization of the mixing equipment. Utility Model Content

[0005] This invention provides a static mixing device with simple structure, high mixing efficiency and low energy consumption, which is suitable for large-scale crude oil desalting systems. It ensures that water and demulsifier are fully dispersed, reduces the amount of reagents used and lowers the salt content after desalting.

[0006] The objective of this utility model can be achieved through the following technical solutions:

[0007] A static mixing device for a large-scale crude oil electrostatic desalting system includes an injection system and a static mixing system arranged in series. The injection system is located at the inlet end of the device, and its venturi nozzles are arranged in the central area of ​​the device pipeline, with the injection outlet direction of the venturi nozzles being opposite to the flow direction of the process medium.

[0008] As a further embodiment of this utility model: the injection system includes an injection pipe, a nozzle distribution device, and a Venturi nozzle, wherein the injection pipe is connected to the Venturi nozzle through the nozzle distribution device.

[0009] As a further embodiment of this utility model: the nozzle distribution device is arranged in a point, straight, circular, cross, or star shape according to the pipe diameter.

[0010] As a further embodiment of this utility model: the Venturi nozzle is fixed to the equipment pipeline through a threaded connection port, and its structure includes a converging cone-shaped inlet section, a short cylindrical throat, and an expanding cone-shaped diffuser section, forming an hourglass shape overall.

[0011] As a further embodiment of this utility model: the cone angle of the inlet section is 15°-30°, and the length is 2-3 times the diameter of the throat; the length of the throat is 0.5-1.5 times the diameter of the throat; the cone angle of the diffuser section is 5°-15° and the length is greater than that of the inlet section.

[0012] As a further embodiment of this utility model, the nozzle size range is: inlet diameter d = 15-200mm, outlet diameter D = 15-200mm, and length L = 30-400mm.

[0013] As a further embodiment of this utility model, the static mixing system adopts a Kenneth static mixer, a corrugated plate static mixer, a Sulzer static mixer, a cross-flow guide plate static mixer, a spiral blade static mixer, or a stacked static mixer.

[0014] As a further embodiment of this invention, the injection system is positioned near the inlet flange.

[0015] As a further embodiment of this utility model: the equipment pipeline is connected to the crude oil pipeline through an inlet flange and an outlet flange.

[0016] As a further embodiment of this utility model: the injection agent includes water, demulsifier or demetallizer, and the process medium is crude oil.

[0017] The beneficial effects of this utility model are:

[0018] (1) This application utilizes the Venturi nozzle structure design to directly inject water, chemical agents, and other injectors into the central part of the mixing equipment pipeline. The flow direction of the water and chemical agents is opposite to the flow direction of the crude oil, which facilitates high-penetration premixing. After reverse premixing, the multiphase fluid flows through the static mixing system to perform left-handed, right-handed, and splitting static mixing processes, thereby achieving full mixing of crude oil, water, and chemical agents.

[0019] (2) When designing the injection system, the nozzle distribution device adopts a point, straight, circular, cross or star arrangement according to the pipe diameter. It has a wide range of applications, so that the reverse injection method can be used to greatly improve the penetration rate of the injection and shorten the mixing time.

[0020] (3) The Venturi nozzle of this application can efficiently convert the kinetic energy and pressure energy of the injection fluid through a three-stage structure of contraction, throat acceleration and diffusion recovery, and achieve low energy consumption, high shear and deep penetration premixing in reverse injection, laying the foundation for the miniaturization of subsequent static mixers. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings.

[0022] Figure 1 This is a schematic diagram of the structure of this utility model;

[0023] Figure 2 This is a schematic diagram of the nozzle distribution device of this utility model;

[0024] Figure 3 This is a schematic diagram of the Venturi nozzle structure of this utility model;

[0025] In the diagram: 1. Inlet flange; 2. Injection system; 20. Nozzle distribution device; 3. Static mixing system; 4. Outlet flange; 5. Venturi nozzle; 50. Threaded connection; 51. Inlet section; 52. Throat; 53. Diffusion section; 6. Crude oil pipeline. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0027] In the description of this utility model, it should be understood that the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model; in the description of this utility model, "a plurality of" or "several" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] Please see Figure 1 As shown, this utility model is a static mixing device for a large-scale crude oil electrostatic desalting system, including an injection injection system 2 and a static mixing system 3 arranged in series. The injection injection system 2 is located at the inlet end of the device, and its venturi nozzle 5 is arranged in the central area of ​​the device pipeline, and the venturi nozzle 5 sets the injection outlet direction to be opposite to the flow direction of the process medium.

[0029] During the use of the static mixing equipment of this application, the equipment pipeline is connected to the crude oil pipeline 6 through the inlet flange 1 and the outlet flange 4. When the crude oil pipeline 6 enters the equipment pipeline in the process transportation direction, the injection system 2 arranges the Venturi nozzles 5 in the central area of ​​the equipment pipeline. The Venturi nozzles 5 are set to spray the injection outlet direction in the opposite direction to the process medium flow direction, so that the injection agents such as water, demulsifiers or demetallizers come into reverse contact with the crude oil to facilitate premixing. Then, they enter the static mixer for mixing. The reverse contact method between the injection agent and the crude oil can replace the injection contact method from the side wall of the pipeline. The reverse injection method adopted in this application greatly improves the injection penetration rate and shortens the mixing time. Combined with the static mixing system 3, it enhances the mixing and dispersion effect. It can be used for mixing crude oil with large flow, high viscosity, and high salt content with water and demulsifier. This allows water and demulsifier to be fully dispersed in the crude oil solution, and the salt in the crude oil will also dissolve into the water. It ensures that after electro-desalting in the electro-desalting tank, the salt content and water content can meet the standards, and the amount of demulsifier can be reduced.

[0030] In its design, the injection system 2 is positioned near the inlet flange 1. The injection system 2 includes an injection pipe, a nozzle distribution device 20, and a Venturi nozzle 5. The injection pipe is connected to the Venturi nozzle 5 via the nozzle distribution device 20. Figure 2The schematic diagram of the nozzle distribution device 20 shown illustrates a design where the nozzle distribution device 20 can be arranged in a point, straight, circular, cross, or star pattern depending on the pipe diameter. For example, small-to-medium-sized pipes smaller than DN500 can use a point, straight, or circular nozzle distribution device 20, while large-sized pipes larger than DN500 can use a cross or star-shaped nozzle distribution device 20. This ensures that the injected agent from the nozzle penetrates evenly against the crude oil. It should be understood that the point-type nozzle distribution device 20 connects a Venturi nozzle 5 to one end of the injection pipe. The linear nozzle distribution device 20 consists of multiple Venturi nozzles 5 arranged from top to bottom and connected to the injection pipe; the circular nozzle distribution device 20 consists of multiple Venturi nozzles 5 evenly distributed along the circumference of a circular branch pipe, which is connected to the injection pipe; the cross-shaped nozzle distribution device 20 uses a cross-shaped pipe connected to the injection pipe, with Venturi nozzles 5 distributed at the center and sides of the cross-shaped pipe; the star-shaped arrangement uses multiple intersecting pipes connected to the injection pipe, with Venturi nozzles 5 distributed along the sides of the multiple intersecting pipes.

[0031] In this specific implementation, such as Figure 3 The Venturi nozzle 5 shown is fixed to the equipment pipeline via a threaded connection 50. The threaded connection 50 facilitates nozzle disassembly and replacement. The Venturi nozzle 5 structure includes a converging cone-shaped inlet section 51, a short cylindrical throat 52, and an expanding cone-shaped diffuser section 53, forming an hourglass shape. The Venturi nozzle 5 of this application, through its three-section structure of contraction, throat acceleration, and diffusion recovery, can efficiently convert the kinetic energy and pressure energy of the injection fluid, achieving low-energy consumption, high-shear, and deep-penetration premixing in reverse injection, laying the foundation for the miniaturization of subsequent static mixers.

[0032] When designing the Venturi nozzle 5, the cone angle of the inlet section 51 is 15°-30°, and its length is 2-3 times the diameter of the throat 52; the length of the throat 52 is 0.5-1.5 times the diameter of the throat 52; the cone angle of the diffuser section 53 is 5°-15° and its length is greater than that of the inlet section 51; the nozzle size range is: inlet diameter d = 15-200mm, outlet diameter D = 15-200mm, and length L = 30-400mm.

[0033] In this specific embodiment, the static mixing system 3 adopts a Kenneth static mixer, a corrugated plate static mixer, a Sulzer static mixer, a cross-flow guide plate static mixer, a spiral blade static mixer, or a stacked static mixer. The static mixing system 3 in this application is used to enhance the mixing and dispersion effect. For example, the static mixing system 3 adopts a Kenneth static mixer. The structure of the Kenneth static mixer is as shown in the patent "Static Mixer" with publication number CN106861479A. The disclosed technical solution is as follows: a hollow mixing unit is disposed in the shell and one end is connected to the outside through an inlet. The hollow mixing unit includes alternating and interconnected left spiral mixing units and right spiral mixing units. The left spiral mixing units and right spiral mixing units are hollow structures and have holes on their surfaces. A mixing channel is formed between the hollow mixing unit and the shell. The advantages of this static mixer are that the mixing unit has a hollow structure with holes on its surface, which can separate the dispersed phase into bubbles, droplets or jets before mixing with the dispersed phase, greatly improving the mixing efficiency. As the fluid passes through the mixer, it is continuously divided and mixed, sometimes rotating left and sometimes right, constantly changing the flow direction. This not only pushes the central liquid flow to the periphery, but also pushes the peripheral liquid flow to the center, thus achieving a good radial mixing effect. At the same time, the rotation of the fluid itself also occurs at the interface where adjacent elements are connected. This radial circulation mixing effect significantly reduces the temperature gradient, velocity gradient and mass gradient of the fluid on the cross-section of the pipe, and the flow state is a plug flow.

[0034] The above description provides a detailed account of one embodiment of the present invention. However, this description is merely a preferred embodiment and should not be construed as limiting the scope of the present invention. All equivalent variations and improvements made within the scope of the claims of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A static mixing device for a large-scale crude oil electrostatic desalting system, characterized in that, The system includes a series-connected injection system (2) and a static mixing system (3). The injection system (2) is located at the inlet of the equipment and includes a Venturi nozzle (5) arranged in the central area of ​​the equipment pipeline. The Venturi nozzle (5) sets the injection outlet direction opposite to the flow direction of the process medium.

2. The static mixing device for a large-scale crude oil electrostatic desalting system according to claim 1, characterized in that, The injection system (2) includes an injection pipe, a nozzle distribution device (20) and a Venturi nozzle (5), wherein the injection pipe is connected to the Venturi nozzle (5) through the nozzle distribution device (20).

3. A static mixing device for a large-scale crude oil electrostatic desalting system according to claim 2, characterized in that, The nozzle distribution device (20) is arranged in a point, straight, circular, cross, or star shape according to the pipe diameter.

4. A static mixing device for a large-scale crude oil electrostatic desalting system according to claim 2, characterized in that, The Venturi nozzle (5) is fixed to the equipment pipeline through a threaded connection (50). Its structure includes a constricting cone-shaped inlet section (51), a short cylindrical throat (52), and an expanding cone-shaped diffuser section (53), and the whole is hourglass-shaped.

5. A static mixing device for a large-scale crude oil electrostatic desalting system according to claim 4, characterized in that, The inlet section (51) has a cone angle of 15°-30° and a length that is 2-3 times the diameter of the throat (52); the throat (52) has a length that is 0.5-1.5 times the diameter of the throat (52); the diffuser section (53) has a cone angle of 5°-15° and a length that is greater than that of the inlet section (51).

6. A static mixing device for a large-scale crude oil electrostatic desalting system according to claim 4, characterized in that, The nozzle size range is: inlet diameter d = 15-200mm, outlet diameter D = 15-200mm, and length L = 30-400mm.

7. A static mixing device for a large-scale crude oil electrostatic desalting system according to claim 1, characterized in that, The static mixing system (3) adopts a Kenneth static mixer, a corrugated plate static mixer, a Sulzer static mixer, a cross-flow plate static mixer, a spiral blade static mixer, or a stacked static mixer.

8. A static mixing device for a large-scale crude oil electrostatic desalting system according to claim 1, characterized in that, The injection system (2) is located near the inlet flange (1).

9. A static mixing device for a large-scale crude oil electrostatic desalting system according to claim 1, characterized in that, The equipment pipeline is connected to the crude oil pipeline (6) through an inlet flange (1) and an outlet flange (4).

10. A static mixing device for a large-scale crude oil electrostatic desalting system according to claim 1, characterized in that, The injection agent includes water, demulsifier or demetallizer, and the process medium is crude oil.

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