A nano-drive produced fluid dehydration device with collector field-cyclonic field coupling

Abstract

The present invention provides a nano-driven produced fluid dehydration device coupled with a collecting field and a cyclonic field to improve the oil-water separation performance of a cyclonic separation structure. An electric field is applied inside the device, and after the nano-driven produced fluid enters the cyclonic structure, it undergoes electric coagulation and centrifugal separation processes simultaneously, which can effectively improve the oil-water separation efficiency; its outer shell includes a cylindrical shell, a conical shell and a splash shield from top to bottom, the cylindrical shell and the large-diameter end of the conical shell are fixedly connected via a flange, and the splash shield is fixedly connected to the small-diameter end of the conical shell via a flange, the upper end of the cylindrical shell is covered with an upper cover, and an oil outlet pipe is provided in the center of the upper cover and coaxially with the central axis of the outer shell, the side of the cylindrical shell is also provided with a tangential inlet, and the inside of the conical shell is provided with a first filter screen, a second filter screen, and a third filter screen coaxially nested together.

Description

Technical Field

[0001] The invention belongs to the field of petrochemical machinery and crude oil dehydration equipment, and particularly relates to a nano-drive produced liquid dehydration device coupled with a collector field and a cyclonic flow field. Background Art

[0002] Most oil reservoirs in my country have low permeability. As oil production continues to increase, oil production in older areas continues to decline. Developing low- and ultra-low-permeability reservoirs is a key source of increased production. However, due to their poor reservoir properties and complex permeability mechanisms, development is difficult and oil production is low. Therefore, increasing oil production from my country's low-permeability reservoirs and reducing development costs are pressing challenges.

[0003] Nanoflooding technology is a cutting-edge, unconventional oil recovery technology. It uses nanoparticles to increase the pressure separating oil droplets from rock, alter formation wettability, and enhance oil recovery. It boasts advantages such as low cost, strong adaptability, and no damage to formations. However, due to the presence of nanoparticles, nanoflooded produced fluid exhibits stable Pickering emulsion properties, making deep dehydration difficult, hindering safe gathering and transportation, and causing corrosion of refining equipment, poor oil quality, and high energy consumption. These issues have become a bottleneck in the development of nanoflooding technology.

[0004] At present, crude oil dehydration technologies are generally divided into three categories: chemical, biological and physical methods. Conventional physical demulsification methods include centrifugal demulsification, electrostatic demulsification, membrane demulsification, grinding demulsification, ultrasonic demulsification and microwave demulsification. Among them, the centrifugal demulsification method creates a vortex field, prompting water droplets to move toward the outer wall relative to the oil droplets, with the oil phase rising and the water phase falling, thereby achieving oil-water separation. The advantages of this method are small equipment size, simple process, and short dehydration treatment time. It is of great significance to achieve efficient nano-drive produced fluid dehydration. In addition, the electrostatic demulsification method induces EHD (electrohydrodynamics) flow at the droplet interface through an electric field, regulates the migration of microparticles on the interface to form a membrane structure in the particle-free area of ​​the interface, strengthens droplet aggregation, and improves oil-water separation ability; the flow field can increase the contact probability by regulating the droplet movement form, strengthen droplet aggregation, and improve oil-water separation ability. Therefore, by coupling the electric field with the flow field, the migration of interfacial nanoparticles is accelerated to form a particle-free zone and the contact probability of the interfacial particle-free zone is increased, which can achieve efficient electrical aggregation of droplets, and is of great significance for maximizing the efficiency of nano-drive produced liquid electro-dehydration and reducing energy consumption. Summary of the Invention

[0005] Based on the above technical status, the purpose of the present invention is to provide a nano-drive produced fluid dehydration equipment with a coupled electric field and a cyclonic field to improve the oil-water separation performance of the cyclonic separation structure. An electric field is applied inside the equipment, and the nano-drive produced fluid enters the cyclonic structure and undergoes electric coagulation and centrifugal separation processes simultaneously, which can effectively improve the oil-water separation efficiency.

[0006] The technical solution adopted by the present invention is as follows: a nano-drive produced fluid dehydration device with a collector field and a cyclonic field coupling, comprising an outer shell of a cyclone structure composed of a cylindrical shell and a conical shell, a tangential inlet being provided on the side of the cylindrical shell, the upper portion of the cylindrical shell being closed by an upper cover, an upper fixed rib being provided inside the outer shell and between the cylindrical shell and the conical shell, a swirl guide vane being installed above the upper fixed rib, a plurality of spiral channels being defined between the circumferential side of the swirl guide vane and the inner wall surface of the cylindrical shell, the spiral channels having the same rotation direction as the tangential inlet, and being used to enhance the swirl of the fluid, so that the fluid after the enhanced swirl enters the inner space of the conical shell;

[0007] The cone shell is provided with a first filter screen, a second filter screen and a third filter screen coaxially nested together, the upper ends of the three filter screens are fixedly installed by an upper fixed rib plate, and the lower ends are fixed to the lower fixed plate, and the lower fixed plate is fixedly installed under the cone shell; wherein the first filter screen is a column type filter screen, the upper end of which is connected to the overflow channel, and the overflow channel is an independent pipeline coaxial with the cylinder shell and the cone shell, which extends upward to the outside of the upper cover, and the lower end of the first filter screen is installed corresponding to the through hole of the lower fixed plate, the second filter screen and the third filter screen are both cone shell type filter screens, the upper ends of the two are fixed on the upper fixed rib plate, and the lower ends of the two are converged together and fixed to the lower fixed plate in contact with the outer wall surface of the lower end of the first filter screen, and the lower fixed plate is further provided with a flow channel penetrating the lower fixed plate between the through hole and the inner wall surface of the lower end of the cone shell;

[0008] The first, second, and third filters are all made of copper and have electrodes installed on their tops. The electrodes of the first and third filters are externally connected to a positive electrode, while the electrode of the second filter is externally connected to a negative electrode. The surfaces of the first, second, and third filters are all coated with an insulating material, and the outer layer of the insulating material is coated with a hydrophilic material.

[0009] A wire box is installed between the upper fixed rib and the swirl guide vane. The electrode sheets on the upper ends of the first, second, and third filters are all sealed within the wire box. An annular flow gap corresponding to the spiral channel is formed between the circumferential side of the wire box and the inner wall of the cylindrical shell. An axial channel is formed in the hollow center of the swirl guide vane. An upper swirl guide vane connecting pipe is provided between the upper surface of the swirl guide vane and the upper cover. An inner wire box connecting pipe is provided within the wire box. An oil outlet pipe is provided above the upper cover. The inner wire box connecting pipe, the axial channel of the swirl guide vane, the upper swirl guide vane connecting pipe, and the oil outlet pipe are sequentially connected to form the overflow channel.

[0010] Furthermore, the filter holes of the first filter screen, the second filter screen, and the third filter screen gradually become smaller from the outside to the inside; and the cone angle of the second filter screen is smaller than the cone angle of the third filter screen.

[0011] Furthermore, the swirl guide vane is provided with two through holes running through its upper and lower surfaces. The two through holes are connected to the internal space of the wire box at the bottom and are connected to a straight tube at the top. The two straight tubes pass through the upper cover to accommodate the wires connecting the electrode sheets.

[0012] A splash shield is further provided below the cone shell. The splash shield has the same inner diameter as the small-diameter end of the cone shell and is fixedly connected below the cone shell. The lower fixing plate is fixed between the cone shell and the splash shield.

[0013] Furthermore, the insulating material is an environmentally friendly semi-inorganic acrylic resin, and the hydrophilic material is a blended polymer consisting of diacrylate and fluorodecyl polyhedral oligomeric silsesquioxane.

[0014] Furthermore, the swirl guide vane and the wire box are both made of insulating materials, and the spiral line angle of the spiral channel of the swirl guide vane is 20°.

[0015] Beneficial effects of the present invention:

[0016] 1. The present invention proposes an electric field-cyclonic field coupling enhanced oil-water separation structure, which consists of a cyclone structure and an electrode structure. By utilizing the difference in electrical conductivity and dielectric constant between oil and water, a high-voltage electric field is applied to the internal flow field of the cyclone, causing small water droplets in the nano-drive produced fluid to quickly coalesce, thereby enhancing the oil-water separation performance of the cyclone.

[0017] 2. The present invention adopts a structure with large outer mesh and small inner mesh in the filter mesh design. Under the action of the cyclone field, water droplets are more likely to move outward in a cyclone, which is beneficial to strengthen the oil-water separation process of the produced liquid when passing through the filter mesh. On the other hand, the filter mesh can also be used to remove solid impurities such as mud, sand, and rust.

[0018] 3. All parts of the device designed by the present invention can be disassembled and installed, which is convenient for replacing parts or cleaning, and the overall operation is simple and fast.

[0019] 4. The device of the present invention has a simple and stable structure, good oil-water separation effect, fast processing speed and low cost, small size, and space saving. It is suitable for multiple fields such as petrochemical industry and wastewater treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the outer contour structure diagram of the dehydration equipment of the present invention;

[0021] Figure 2 is a cross-sectional view of the dehydration device of the present invention;

[0022] Figure 3 This is a front view of the shell of the dehydration equipment of the present invention;

[0023] Figure 41. It is a top view of the shell of the dehydration equipment of the present invention;

[0024] Figure 5 Schematic diagram of the connection above the three-layer filter screen of the dehydration equipment of the present invention;

[0025] Figure 6 Schematic diagram of the connection below the three-layer filter screen of the dehydration equipment of the present invention;

[0026] Figure 7 2. It is a schematic diagram of the three-dimensional structure of the swirl guide vane of the dehydration equipment of the present invention;

[0027] Figure 8 is a side view of the swirl guide vane of the dehydration equipment of the present invention;

[0028] Figure 9 It is a schematic structural diagram of the first filter screen of the dehydration equipment of the present invention;

[0029] Figure 10 It is a schematic structural diagram of the second filter screen of the dehydration equipment of the present invention;

[0030] Figure 11 It is a schematic diagram of the structure of the third filter screen of the dehydration equipment of the present invention;

[0031] In the figure: 1. Upper cover, 2. Upper connecting pipe of swirl guide vane, 3. Straight pipe, 4. swirl guide vane, 5. Wire box, 6. Upper fixed rib, 701. First filter screen, 702. Second filter screen, 703. Third filter screen, 801. First connecting piece, 802. Second connecting piece, 803. Third connecting piece, 9. Lower fixed plate, 10. Splash shield, 11. Conical shell, 12. Cylindrical shell, 13. Connecting pipe in wire box, 14. Tangential inlet, 15. Oil outlet pipe. DETAILED DESCRIPTION

[0032] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like to indicate directions or positional relationships are for simplified description, and do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0034] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0035] Figure 1 This is the outer contour structure diagram of the dehydration equipment of the present invention. Figure 2 It is a cross-sectional view of the dehydration device of the present invention; Figure 1 、 Figure 2 The nano-drive produced fluid dehydration equipment coupled with a collecting field and a cyclonic flow field of the present invention has an outer shell comprising a cylindrical shell 12, a conical shell 11 and a splash shield 10 from top to bottom. The cylindrical shell 12 is fixedly connected to the large-diameter end of the conical shell 11 via a flange, and the splash shield 10 is fixedly connected to the small-diameter end of the conical shell 11 via a flange. The upper end of the cylindrical shell 12 is covered with an upper cover 1, and an oil outlet pipe 15 is provided in the center of the upper cover 1 and coaxially with the central axis of the outer shell. A tangential inlet 14 is also provided on the side of the cylindrical shell 12.

[0036] See also Figure 2An upper fixed rib 6 is provided inside the outer shell and between the cylindrical shell 12 and the conical shell 11, and a wire box 5 is installed above the upper fixed rib 6. A swirl guide vane 4 is installed inside the cylindrical shell 12 and above the wire box 5. A spiral channel is defined between the circumferential side of the swirl guide vane 4 and the inner wall of the cylindrical shell 12. The spiral channel is used to create swirl for the fluid entering from the tangential inlet 14. A flow annular gap corresponding to the spiral channel is formed between the circumferential side of the wire box 5 and the inner wall of the cylindrical shell 12. The annular area of ​​the upper fixed rib 6 not covered by the wire box 5 is supported by ribs to form a flow gap. The middle part of the swirl guide vane 4 is hollow to form an axial channel. A swirl guide vane upper connecting pipe 2 is provided between the upper surface of the swirl guide vane 4 and the upper cover 1. A wire box inner connecting pipe 13 is provided inside the wire box 5. The wire box inner connecting pipe 13, the axial channel of the swirl guide vane 4, the swirl guide vane upper connecting pipe 2, and the oil outlet pipe 15 are connected in sequence to form the central overflow channel of the dehydration equipment of the present invention. The interior of the conical shell 11 is provided with a first filter screen 701, a second filter screen 702, and a third filter screen 703 which are coaxially nested together. The upper ends of the three-layer filter screens are fixedly installed by the upper fixed rib 6, and the lower ends are fixed to the lower fixed plate 9. The first filter screen 701 is a column type filter screen, the upper end of which is fixed to the upper fixed rib 6 by the first connecting member 801, and is connected to the connecting pipe 13 in the wire box. The second filter screen 702 is a conical shell type filter screen, the upper end of which is fixed to the upper fixed rib 6 by the second connecting member 802. The third filter screen 703 is a conical shell type filter screen, the upper end of which is fixed to the upper fixed rib 6 by the third connecting member 803.

[0037] Figure 5 This is a schematic diagram of the connection above the three-layer filter screen of the dehydration equipment of the present invention. Figure 6 This is a schematic diagram of the lower connection of the three-layer filter screen of the dehydration equipment of the present invention. As shown in the figure, the lower ends of the three-layer filter screen are gathered together and fixed on the lower fixed plate 9. The center of the lower fixed plate 9 has a through hole corresponding to the internal channel of the first filter screen 701. The periphery of the through hole is also provided with a plurality of flow channels that pass through the lower fixed plate 9 from top to bottom. The lower fixed plate 9 is flange-fixed between the cone shell 11 and the splash shield 10. The filter screen of the three-layer filter screen gradually becomes smaller from the outer layer to the inner layer, that is, the filter holes of the first filter screen 701 are smaller than the filter holes of the second filter screen 702, and the filter holes of the second filter screen 702 are smaller than the filter holes of the third filter screen 703. Under the action of centrifugal force, the water droplets of the external vortex flow migrate outward more easily, which is beneficial to the enhanced oil-water separation process of the produced liquid during the process of flowing through the filter screen. On the other hand, the filter screen can remove a small amount of entrained solid impurities such as mud, sand, rust, etc. In addition, the taper of the second filter screen 702 is smaller than that of the third filter screen 703, so that the dehydration equipment can achieve the purpose of less weakening the internal tangential velocity and the internal axial velocity of the cyclone field without disturbing the flow direction of the fluid.

[0038] See also Figure 9 、 Figure 10 、 Figure 11 , schematically showing the structure of the three-layer filter screen. Electrode sheets are provided on the top of the three-layer filter screen. The three-layer filter screen is made of copper. The surface of the filter screen is coated with insulating material (environmentally friendly semi-inorganic acrylic resin) and hydrophilic material (a blended polymer composed of diacrylate and fluorodecyl polyhedral oligomeric silsesquioxane) to enhance the droplet coalescence effect under the electric field, so that the equipment has a higher separation efficiency; in addition, the filter screen is made oleophobic, which can prevent the dehydration equipment from being contaminated by oil and improve the life of the device. The three electrode sheets are all sealed inside the wire box 5 and connected to the external power supply through wires. The upper fixed rib 6 seals the bottom of the wire box 5 and fixes the positions of the three layers of filter screens and the three electrode sheets. The electrode sheets of the first filter screen 701 and the third filter screen 703 are connected to the positive pole, and the electrode sheet of the second filter screen 702 is connected to the negative pole. After the external power supply is conductive, multiple electric fields are formed between the three layers of copper filter screens, causing the droplets of the produced liquid to elongate and oscillate. The elongation of the droplets causes the interface film to deform and rupture, thereby enhancing the agglomeration effect and strengthening the electro-agglomeration process of the fine droplets. After passing through each layer of filter screen, the degree of electro-agglomeration of water droplets in the nano-drive produced liquid continues to increase. After passing through the three layers of filter screens, the purity of the oil phase in the first filter screen 701 is already very high. At this time, since the oil-water mixture after separation is still under the action of centrifugal sedimentation, due to the difference in density, the inner oil phase is forced to change direction under the pressure of the contraction of the outer mixed liquid, and move upward, forming an internal vortex, which is transported out of the oil outlet pipe 15 and becomes overflow, while the water phase and a very small part of the produced liquid that has not been completely separated continue to move downward in a spiral along the cylinder wall, forming an external vortex, and flow out of the splash shield 10 for recovery.

[0039] Figure 3 This is a front view of the shell of the dehydration equipment of the present invention, Figure 4 It is a top view of the shell of the dehydration equipment of the present invention; as shown in the figure, the shell 12 is a cylindrical shell structure, and a tangential inlet pipe is fixedly set on its side, and the tangential inlet pipe is set close to the upper surface of the shell 12.

[0040] Figure 7 This is a schematic diagram of the three-dimensional structure of the swirl guide vanes of the dehydration equipment of the present invention. Figure 8 This is a side view of the swirl guide vane of the dehydration equipment of the present invention; the outer diameter of the swirl guide vane 4 is adapted to the inner diameter of the cylinder shell 12, and multiple spiral channels are formed on its circumferential side. After the swirl guide vane 4 is installed inside the cylinder shell 12, it is located above the wire box 5 and below the tangential inlet 14. The outer sides of the multiple spiral channels are closed by the inner wall of the cylinder shell 12 to form multiple independent swirl flow channels. Figure 7Four blind holes are provided on the circumferential side of the axial channel of the swirl guide vane 4 for installing bolts to fix the flange of the connecting pipe 2 on the swirl guide vane. The swirl guide vane 4 is also provided with two through holes running through its upper and lower surfaces. The two through holes are connected to the internal space of the wire box 5 at the bottom and are connected to a straight pipe 3 at the top. The two straight pipes 3 pass through the upper cover 1 for passing the wires connecting the positive and negative poles of the electrode sheets to avoid direct contact between the wires and the produced fluid, which may cause corrosion of the wires and short circuit faults.

[0041] After the nano-driven produced fluid enters the interior of the cylindrical shell 12 from the tangential inlet 14, the produced fluid forms a vortex with a certain intensity. However, the circumferential and axial speeds of the vortex field formed in this state are not enough to support the continuous and efficient flow of the produced fluid inside the equipment. When the produced fluid passes through the vortex guide vane 4, the vortex field is effectively strengthened, so that when the produced fluid enters the cone shell, the separation efficiency of the three-layer filter screen is greatly improved; the produced fluid first contacts the inner wall surface of the cone shell 11 with a conical structure, which can effectively increase the internal tangential velocity and the axial speed of the inner vortex of the dehydration equipment, and once again strengthen the vortex kinetic energy of the fluid, so that the nano-driven produced fluid can be fully separated when passing through the third filter screen 703, the second filter screen 702 and the first filter screen 701 in sequence, thereby improving the oil-water separation efficiency.

[0042] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that, based on the technical solution of the present invention, those skilled in the art can make modifications or deformations of various equivalent structures or equivalent processes without creative work, or directly or indirectly apply them to other related technical fields, which are still within the scope of protection of the present invention.

Claims

1. A nano-drive produced fluid dehydration device with a collector field-cyclonic field coupling, comprising an outer shell of a cyclone structure composed of a cylindrical shell and a conical shell, a tangential inlet being provided on the side of the cylindrical shell, and the upper part of the cylindrical shell being closed by an upper cover, characterized in that: An upper fixed rib is provided inside the outer shell and between the cylindrical shell and the conical shell. A swirl guide vane is installed above the upper fixed rib. A plurality of spiral channels are defined between the circumferential side of the swirl guide vane and the inner wall of the cylindrical shell. The rotation direction of the spiral channel is the same as that of the tangential inlet, and is used to enhance the swirl of the fluid. The fluid after the enhanced swirl enters the inner space of the conical shell. The cone shell is provided with a first filter screen, a second filter screen and a third filter screen coaxially nested together, the upper ends of the three filter screens are fixedly installed by an upper fixed rib plate, and the lower ends are fixed to the lower fixed plate, and the lower fixed plate is fixedly installed under the cone shell; wherein the first filter screen is a column type filter screen, the upper end of which is connected to the overflow channel, and the overflow channel is an independent pipeline coaxial with the cylinder shell and the cone shell, which extends upward to the outside of the upper cover, and the lower end of the first filter screen is installed corresponding to the through hole of the lower fixed plate, the second filter screen and the third filter screen are both cone shell type filter screens, the upper ends of the two are fixed on the upper fixed rib plate, and the lower ends of the two are converged together and adhered to the outer wall surface of the lower end of the first filter screen and fixed to the lower fixed plate, and the lower fixed plate is further provided with a flow channel penetrating the lower fixed plate between the through hole and the inner wall surface of the lower end of the cone shell; The first filter, the second filter, and the third filter are all made of copper, and are provided with electrode sheets on their upper ends. The electrode sheets of the first filter and the third filter are externally connected to a positive electrode, and the electrode sheet of the second filter is externally connected to a negative electrode. The surfaces of the first filter screen, the second filter screen, and the third filter screen are all coated with insulating material, and the outer layer of the insulating material is coated with a hydrophilic material; The filter holes of the first filter screen, the second filter screen and the third filter screen gradually become smaller from the outside to the inside.

2. The dehydration device according to claim 1, further characterized in that: A wire box is installed between the upper fixed rib and the swirl guide vane, and the electrode sheets on the upper ends of the first filter screen, the second filter screen, and the third filter screen are all sealed and accommodated inside the wire box; A flow-through annular gap corresponding to the spiral channel is formed between the peripheral side surface of the wire box and the inner wall surface of the cylinder shell.

3. The dehydration device according to claim 2, further characterized in that: The middle part of the swirl guide vane is hollow to form an axial channel. A swirl guide vane upper connecting pipe is provided between the upper surface of the swirl guide vane and the upper cover. A wire box inner connecting pipe is provided inside the wire box. An oil outlet pipe is provided above the upper cover. The wire box inner connecting pipe, the axial channel of the swirl guide vane, the swirl guide vane upper connecting pipe, and the oil outlet pipe are connected in sequence to form the overflow channel.

4. The dehydration device according to claim 2, further characterized in that: The swirl guide vane is also provided with two through holes penetrating its upper and lower surfaces. The lower part of the two through holes is connected to the internal space of the wire box and the upper part is connected to a straight pipe respectively. The upper part of the two straight pipes passes through the upper cover to accommodate the wires connected to the electrode sheets.

5. The dehydration device according to claim 1, further characterized in that: The utility model also comprises a splash-proof cover, which has the same inner diameter as the small-diameter end of the cone shell and is fixedly connected to the bottom of the cone shell.

6. The dehydration device according to claim 1, further characterized in that: The insulating material is environmentally friendly semi-inorganic acrylic resin, and the hydrophilic material is a blended polymer consisting of diacrylate and fluorodecyl polyhedral oligomeric silsesquioxane.

7. The dehydration device according to claim 1, further characterized in that: The cone angle of the second filter screen is smaller than the cone angle of the third filter screen.

8. The dehydration device according to claim 1, further characterized in that: The swirl guide vane and the conductor box are both made of insulating materials, and the spiral line wrap angle of the spiral channel of the swirl guide vane is 20°.

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