A catalytic cracking feed atomizing nozzle

Abstract

The present invention discloses a catalytic cracking feed atomizing nozzle, comprising a steam chamber, a premixing chamber, a dispersion chamber, and a nozzle, which are sequentially connected and coaxially arranged. The steam chamber is connected to an atomizing steam inlet. A fixed plate is provided between the steam chamber and the premixing chamber. The fixed plate is provided with a plurality of through holes, and an air distribution pipe is fixedly connected to the through holes. A tangential feed oil inlet is provided on the outer side of the premixing chamber. A spiral plate is provided in the premixing chamber along the axial direction. The air distribution pipe extends through the spiral plate to the dispersion chamber, and a dispersion structure is provided in the dispersion chamber. The present invention provides a catalytic cracking feed atomizing nozzle, which can achieve multi-stage atomization of the feed oil, effectively eliminate large-diameter droplets, and significantly improve the size distribution of the feed oil droplets sprayed from the nozzle, thereby improving the contact between the feed oil and the catalyst and optimizing the product distribution of the catalytic cracking.

Description

Technical Field

[0001] The invention belongs to the technical field of catalytic cracking devices, and in particular relates to a catalytic cracking feed atomizing nozzle. Background Art

[0002] Feedstock atomizing nozzles are a crucial component of catalytic cracking units in the petroleum refining industry. Their function is to break up and atomize the feedstock into a large number of fine droplets. These droplets are then sprayed into the catalytic cracking riser reactor, where they mix and react with the catalyst. In the FCC process, the performance of the feed nozzle plays a crucial role in the cracking reaction and product distribution. Well-atomized feedstock in contact with the high-temperature catalyst rapidly vaporizes the feedstock, reducing the formation of "wet catalyst" (unvaporized oil adhering to the catalyst surface), improving product distribution, and reducing coking in the FCC recirculation system, resulting in significant economic benefits.

[0003] Currently, catalytic cracking feed nozzles are generally classified into the following categories: 1. Throat-type atomizing nozzles, which utilize a converging-diverging throat to increase the relative velocity of gas and liquid, relying on the velocity difference between the gas and liquid phases to atomize the feedstock; 2. Target-type nozzles, in which the feedstock vertically impacts a metal target under high pressure, then reacts with a transverse airflow for a primary atomization, forming a gas-liquid two-phase flow, which is then accelerated at the nozzle outlet for secondary atomization. These nozzles offer good atomization effects, but require higher feed pressures and more atomizing medium, resulting in high energy consumption and high equipment and operating costs; 3. Swirl-type nozzles, in which the gas-liquid mixture rapidly swirls in a gas-liquid two-phase cyclone to achieve primary atomization, followed by secondary atomization at the nozzle orifice; 4. Bubble-type atomizing nozzles, in which high-pressure atomizing steam is injected into the flowing feedstock oil through multiple small holes, causing a large number of bubbles to be incorporated into the feedstock, forming a uniform bubble flow. The bubbles serve as the driving force, utilizing the generation, movement, and deformation of the bubbles until they are ejected from the nozzle outlet and burst, thereby atomizing the feedstock. The above types of nozzles have problems such as large atomized particle size, high spraying speed, uneven atomization, and high energy consumption.

[0004] Patent 201610537088.X discloses a catalytic feedstock pretreatment method. This method utilizes an emulsifying tube (with a pore size of 1-60,000 nm) to disperse emulsified water into the feedstock for water-in-oil emulsification. The resulting emulsified feedstock has an oil droplet size of less than 50 microns. The oil is then sprayed through a nozzle, effectively atomizing the feedstock. While this method is simple, the increased use of emulsified water increases the water content entering the riser reactor, leading to hydrothermal deactivation of the catalytic cracking catalyst and hindering the catalytic cracking reaction. Furthermore, this patent adds a feedstock pretreatment step, increasing equipment investment.

[0005] Based on the above problems, the present invention proposes a feed atomizing nozzle to solve the problems of large atomizing particle size, uneven atomization, high spraying speed, and high energy consumption of existing nozzles. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a catalytic cracking feed atomizing nozzle, which can achieve multi-stage atomization of the raw oil, effectively eliminate large-diameter droplets, and at the same time significantly improve the size distribution of the raw oil droplets sprayed from the nozzle, thereby improving the contact between the raw oil and the catalyst and optimizing the product distribution of catalytic cracking.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A catalytic cracking feed atomizing nozzle, the atomizing nozzle comprising a steam chamber, a premixing chamber, a dispersion chamber and a nozzle which are connected in sequence and arranged coaxially, the steam chamber being connected to an atomizing steam inlet, a fixed plate being provided between the steam chamber and the premixing chamber, a plurality of through holes being provided on the fixed plate, an air distribution pipe being fixedly connected to the through holes, a tangential crude oil inlet being provided on the outside of the premixing chamber, a spiral plate being provided in the premixing chamber along the axial direction, the air distribution pipe passing through the spiral plate and extending to the dispersion chamber, and a dispersion structure being provided in the dispersion chamber.

[0009] Preferably, the angle between the spiral plate and the axis of the premixing chamber is set to β, and β=5°-60°.

[0010] Preferably, the dispersed structure is composed of a diameter-reducing section, a straight pipe section and a diameter-expanding section that are sequentially connected and coaxially arranged, the taper of the diameter-expanding section and the diameter-reducing section is 4°-15°, and at least one group of the dispersed structure is provided.

[0011] Preferably, the tangential feedstock oil inlet is circular or rectangular, and the angle between the tangential feedstock oil inlet and the axis of the premixing chamber is set to α, and α=30°-90°.

[0012] Preferably, the starting position of the spiral plate is set at the front end of the tangential raw oil inlet, and the ending position is set at the end of the air distribution pipe away from the fixed plate; the rotation direction of the spiral plate is consistent with the direction of the raw oil flowing to the dispersion chamber after entering the premixing chamber, and a number of balancing holes are provided on the spiral plate.

[0013] Preferably, the gas distribution pipe is a microporous tube, and the microporous tube can be one of a sintered metal powder microporous tube, a metal wire mesh tube or a ceramic powder sintered tube.

[0014] Preferably, the micropore diameter of the microporous tube is 50-1000 μm, and the wall thickness of the microporous tube is 5-20 mm.

[0015] Preferably, the opening shape of the nozzle is slit-shaped.

[0016] Preferably, the cavity between the nozzle and the expanded diameter section forms a remixing chamber.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The catalytic cracking feed atomizing nozzle provided by the present invention allows micro-nano bubbles to be quickly and evenly dispersed into the crude oil through the arrangement of the air distribution pipe and the spiral plate in the premixing chamber, and the crude oil and the atomizing steam are quickly and evenly mixed. The gas-liquid mixture evenly dispersed with the atomizing steam is precisely mixed in multiple streams and zones; the gas-liquid two-phase is precisely mixed after entering each diameter-reducing section and the straight pipe section and the diameter-expanding section corresponding to each diameter-reducing section. The precisely mixed gas-liquid mixtures are mixed together again in the remixing chamber and then ejected from the nozzle; the combined effect of the air distribution pipe, the spiral plate, the multi-zone dispersion structure (multiple diameter-reducing sections, multiple straight pipe sections, multiple diameter-expanding sections), and the remixing chamber greatly enhances the atomizing effect of the nozzle, and the mist particle size (Sawtell average particle size and mass median diameter) of the crude oil reaches about 30 μm.

[0019] (2) The catalytic cracking feed atomizing nozzle provided by the present invention allows the raw oil to spiral into the premixing chamber through the arrangement of the tangential raw oil inlet and the spiral plate. The raw oil is affected by its own surface tension and external force. When the raw oil flow rate reaches a certain value, the external force on the raw oil is greater than the surface tension, so that a large number of droplets are thrown out from the spiral plate and the periphery of the raw oil body, thereby achieving a primary dispersion of the raw oil; through the arrangement of the air distribution pipe and the spiral plate, small bubbles of micro-nano level are vertically injected into the raw oil, which have an impact on the raw oil, thereby achieving a secondary dispersion of the raw oil; the raw oil diversion stream with small bubbles evenly dispersed therein enters each diameter reduction section, and as the bubble flow enters the diameter reduction section, the gas-liquid two-phase velocity increases, the spiral effect increases, and the raw oil is expanded into a thin film under the spiral effect, thereby increasing the surface area of ​​the raw oil, thereby achieving a tertiary dispersion of the raw oil; the gas-liquid mixture continues to flow forward, and in each straight pipe section, due to the difference in gas-liquid two-phase velocity, the atomizing steam produces a strong tearing and shearing effect on the raw oil, thereby achieving a fourth dispersion of the raw oil. At the same time, as the gas-liquid mixture passes through the straight pipe section, the atomizing steam is compressed. When the atomizing steam flows from the straight pipe section into the expanded diameter section, the volume of the atomizing steam expands, squeezing the crude oil, further increasing the atomizing steam's dispersing effect on the crude oil. After the multiple streams of gas-liquid mixture flow out of the expanded diameter section, they enter the remixing chamber for blending. After the multiple streams of gas-liquid mixture are evenly blended, they are ejected through the nozzle through the nozzle. Because the ambient pressure outside the nozzle is lower than the pressure inside the nozzle, the small bubbles of atomizing steam rapidly expand and burst at the nozzle orifice, breaking the crude oil into droplets, achieving a five-fold dispersion of the crude oil and atomizing it. After the five-fold dispersion and mixing, the droplet size distribution of the crude oil is significantly improved, which in turn improves the contact between the crude oil and the catalyst and optimizes the product distribution of catalytic cracking.

[0020] (3) The catalytic cracking feed atomizing nozzle provided by the present invention is that the crude oil enters the premixing chamber through the crude oil inlet and the spiral plate, and the atomizing steam enters the premixing chamber through the air distribution pipe. The setting of the spiral plate enables the crude oil to move tangentially along the straight section and perpendicular to the direction of the atomizing steam coming out of the air distribution pipe. The vertical cutting effect of the crude oil on the atomizing steam promotes the formation of micro-nano small bubbles, thereby allowing the atomizing steam to be evenly and quickly dispersed in the crude oil; at the same time, the setting of the spiral plate increases the movement trajectory of the gas-liquid mixture in the premixing chamber, thereby increasing the residence time of the gas-liquid mixture in the premixing chamber, which is beneficial to the full mixing of the atomizing steam and the crude oil in the premixing chamber, and the setting of the spiral plate increases the disturbance between the gas-liquid mixture, which is beneficial to the mixing between the atomizing steam and the crude oil, and is beneficial to the more even dispersion of small bubbles in the crude oil to form a uniform bubble flow.

[0021] (4) The catalytic cracking feed atomizing nozzle provided by the present invention enables a large number of micro-nano bubbles to be quickly and evenly dispersed into the crude oil through the arrangement of a porous tube and a spiral plate. The formation of micro-nano bubbles increases the number of bubbles in the same volume of atomizing steam, increases the surface area of ​​the atomizing steam, and increases the gas-liquid contact area, thereby enhancing the shearing effect of the atomizing steam on the crude oil and the impact effect of the atomizing steam explosion on the crude oil, thereby strengthening the atomizing effect of the nozzle.

[0022] (5) The catalytic cracking feed atomizing nozzle provided by the present invention has a more obvious effect of the same volume of atomizing steam due to the formation of micro-nano bubbles and the uniform mixing of micro-nano bubbles with the raw oil. Therefore, the atomizing steam consumption can be appropriately reduced, thereby reducing the raw oil spraying speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the catalytic cracking feed atomizing nozzle of the present invention;

[0024] Figure 2 Schematic diagram of the cross-sectional structure of the nozzle of the present invention;

[0025] Figure 3 A distribution diagram of the dispersed structure of the present invention;

[0026] Figure 4 Another distribution diagram of the dispersed structure of the present invention;

[0027] Figure 5 This is a schematic diagram of the tangential feed oil inlet of the present invention;

[0028] Figure 6 This is a schematic diagram of the oblique feedstock oil inlet of the present invention;

[0029] Figure 7 This is a schematic structural diagram of the gas distribution pipe and spiral plate inside the gas-liquid mixing chamber of the present invention;

[0030] Among them, 1. nozzle; 2. expansion section; 21. expansion section I; 22. expansion section II; 3. straight pipe section; 31. straight pipe section I; 32. straight pipe section II; 4. reduction section; 41. reduction section I; 42. reduction section II; 5. gas distribution pipe; 6. dispersion chamber; 7. spiral plate; 8. premixing chamber; 9. tangential crude oil inlet; 10. fixed plate; 11. atomizing steam inlet; 12. remixing chamber; 13. steam chamber. DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0033] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0034] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the invention is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0035] In addition, the terms "first", "second", etc., if used, are merely used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0036] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0037] like Figure 1 and Figure 7As shown, a catalytic cracking feed atomizing nozzle includes a steam chamber 13, a premixing chamber 8, a dispersion chamber 6 and a nozzle 1 that are connected in sequence and coaxially arranged. The steam chamber 13 is connected to the atomizing steam inlet 11. A fixed plate 10 is provided between the steam chamber 13 and the premixing chamber 8. The fixed plate 10 is provided with a plurality of through holes, and an air distribution pipe 5 is fixedly connected to the through holes. A tangential raw oil inlet 9 is provided on the outside of the premixing chamber 8. A spiral plate 7 is provided in the premixing chamber 8 along the axial direction. The air distribution pipe 5 passes through the spiral plate 7 and extends to the dispersion chamber 6. A dispersion structure is provided in the dispersion chamber 6.

[0038] In some embodiments, the angle between the spiral plate 7 and the axis of the premixing chamber 8 is set to β, and β = 5°-60°, which can be 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, preferably 45°.

[0039] Specifically, a spiral plate is provided, and the gas-liquid mixture enters the reduced diameter section by performing spiral motion. At the same time, as the moving cross-sectional area becomes smaller, the velocity of the gas-liquid two phases increases, and the spiral effect increases. Under the spiral effect, the crude oil is spread into a thin film, which increases the surface area of ​​the crude oil and enhances the atomization quality of the crude oil.

[0040] In some embodiments, as Figure 3 、 Figure 4 As shown, the dispersed structure is composed of a reduced diameter section 4, a straight pipe section 3 and an expanded diameter section 2 that are sequentially connected and coaxially arranged. The taper of the expanded diameter section 2 and the reduced diameter section 4 is 4°-15°, which can be 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12°, 13°, 14°, 15°, preferably 7°; the dispersed structure is provided in at least one group, and multiple groups can also be provided.

[0041] Specifically, when multiple dispersion structures are set up, the uniformly mixed gas-liquid mixture coming out of the gas-liquid mixing chamber is dispersed into multiple streams and enters each reduced diameter section due to the precise mixing through multiple reduced diameter sections, multiple straight pipe sections, and multiple expanded diameter sections. The surface area of ​​the crude oil is increased, the gas-liquid contact area is increased, the tearing and shearing effects of the atomizing steam on the crude oil are enhanced, and the atomization effect of the nozzle is enhanced.

[0042] In some embodiments, as Figure 5 、 Figure 6 As shown, the tangential feedstock oil inlet 9 is circular or rectangular, and the angle between the tangential feedstock oil inlet 9 and the axis of the premixing chamber 8 is set to α, and α = 30°-90°, which can be 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, 90°, preferably 45°.

[0043] In some embodiments, as Figure 7 As shown, the starting position of the spiral plate 7 is set at the front end of the tangential raw oil inlet 9, and the end position is set at the end of the air distribution pipe 5 away from the fixed plate 10; the rotation direction of the spiral plate 7 is consistent with the direction in which the raw oil flows to the dispersion chamber 6 after entering the premixing chamber 8, and a number of balancing holes are provided on the spiral plate 7, and the balancing holes can make the hydraulic pressure on the entire spiral plate equivalent.

[0044] In some embodiments, the gas distribution pipe 5 is a microporous tube, which can be a sintered metal powder microporous tube, a metal wire mesh tube, or a ceramic powder sintered tube.

[0045] Specifically, the microporous tube can make the atomized steam entering the premixing chamber form micro-nano bubbles, thereby making the atomized steam evenly and quickly dispersed in the crude oil.

[0046] In some embodiments, the pore diameter of the microporous tube is 50-1000 μm, which can be 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm, 700 μm, 750 μm, 800 μm, 850 μm, 900 μm, 950 μm, 1000 μm, and preferably 200 μm; the wall thickness of the microporous tube is 5-20 mm, which can be 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, 20 mm, and preferably 10 mm.

[0047] In some embodiments, as Figure 2 As shown, the opening shape of the nozzle 1 is a slit shape.

[0048] In some embodiments, the cavity between the nozzle 1 and the expanded diameter section 2 forms a remixing chamber 12 .

[0049] The fixed connection described in the present invention can be welding, threaded or flange connection, etc.

[0050] The catalytic cracking feed atomizing nozzle provided by the present invention operates as follows: Feedstock enters the premixing chamber 8 through a tangential feedstock inlet 9 and a spiral plate 7. The feedstock undergoes a spiral motion, ejecting a large number of droplets around the spiral plate 7 and the bulk of the feedstock, achieving primary dispersion of the feedstock. Atomizing steam passes through the atomizing steam inlet 11, through the gas distribution pipe 5 and the spiral plate 7, forming micro-nanoscale bubbles. These bubbles are then injected vertically into the feedstock, impacting the feedstock and achieving secondary dispersion. Simultaneously, the micro-nanopores on the gas distribution pipe 5 and the spiral plate 7 promote the formation of micro-nanoscale bubbles, while the arrangement of the spiral plate 7 in the premixing chamber 8 ensures uniform and rapid dispersion of the bubbles into the feedstock. The gas-liquid mixture spirally blends in the premixing chamber 8, allowing the small bubbles to evenly enter the feedstock. The gas-liquid mixture then evenly enters each of the reduced-diameter sections 4, increasing the gas-liquid two-phase velocity and the spiral action. This spiral action spreads the feedstock into a thin film, increasing its surface area and achieving tertiary dispersion. Then the gas-liquid mixture enters each straight pipe section 3, where the gas-liquid two-phase movement accelerates. The speed difference between the gas-liquid two-phase movement causes the crude oil to be broken into very small droplets by the atomized steam, forming a gas-liquid two-phase atomized flow, thereby realizing four-fold dispersion of the crude oil; the gas-liquid two-phase atomized flow passes through each expanded diameter section 2 and enters the remixing chamber 12, where multiple streams of gas-liquid mixture are mixed evenly again and then ejected from the nozzle through the nozzle 1, where the small bubbles mixed in the crude oil rapidly expand and rupture at the nozzle 1, breaking the crude oil into droplets, thereby realizing five-fold dispersion and the crude oil is atomized.

[0051] Example 1

[0052] A catalytic cracking feed atomizing nozzle, the atomizing nozzle includes a steam chamber 13, a premixing chamber 8, a dispersion chamber 6 and a nozzle 1 which are connected in sequence and coaxially arranged. The steam chamber 13 is connected to an atomizing steam inlet 11. A fixed plate 10 is provided between the steam chamber 13 and the premixing chamber 8. The fixed plate 10 is fixedly connected to the premixing chamber 8 and the steam chamber 13. A plurality of through holes are opened on the fixed plate 10. An air distribution pipe 5 is fixedly connected to the through holes. The atomizing steam in the steam chamber enters the air distribution pipe 5 through the through holes, and then enters the premixing chamber 8 through the air distribution pipe 5 to mix with the crude oil. A tangential crude oil inlet 9 is provided on the outside of the premixing chamber 8. A spiral plate 7 is provided in the premixing chamber 8 along the axial direction. The air distribution pipe 5 passes through the spiral plate 7 and extends to the dispersion chamber 6. A dispersion structure is provided in the dispersion chamber 6.

[0053] In this embodiment, the angle between the spiral plate 7 and the axis of the premixing chamber 8 is set to β, and β=45°.

[0054] In this embodiment, if Figure 3The dispersed structure is composed of a reduced diameter section 4, a straight pipe section 3 and an expanded diameter section 2 that are connected in sequence and coaxially arranged. The taper of the expanded diameter section 2 is 7°, and the taper of the reduced diameter section 4 is 10°. The dispersed structure is arranged in 6 groups.

[0055] In this embodiment, if Figure 3 As shown, the diameter of the straight pipe section ⅠⅠ32 is twice the diameter of the straight pipe section Ⅰ31, and the diameter of the large-diameter end of the reduced diameter section ⅠⅠ42 is twice the diameter of the large-diameter end of the reduced diameter section Ⅰ41; the reduced diameter section Ⅰ, straight pipe section Ⅰ, and expanded diameter section Ⅰ are set in 3 groups, and the reduced diameter section ⅠⅠ, straight pipe section ⅠⅠ, and expanded diameter section ⅠⅠ are set in 3 groups.

[0056] In this embodiment, the tangential feedstock oil inlet 9 is circular, and the angle between the tangential feedstock oil inlet 9 and the axis of the premixing chamber 8 is set to α, and α=45°.

[0057] In this embodiment, the starting position of the spiral plate 7 is set at the front end of the tangential raw oil inlet 9, and the ending position is set at the end of the air distribution pipe 5 away from the fixed plate 10; the rotation direction of the spiral plate 7 is consistent with the direction in which the raw oil flows to the dispersion chamber 6 after entering the premixing chamber 8, and a number of balancing holes are provided on the spiral plate 7.

[0058] In this embodiment, the gas distribution pipe 5 is a microporous tube, and the microporous tube is a sintered metal powder microporous tube.

[0059] In this embodiment, the micropore diameter of the microporous tube is 100 μm, and the tube wall thickness of the microporous tube is 10 mm.

[0060] In this embodiment, the opening shape of the nozzle 1 is a rectangular slit.

[0061] In this embodiment, the cavity between the nozzle 1 and the expanded diameter section 2 forms a remixing chamber 12 .

[0062] In this embodiment, the fixed connection is welding.

[0063] The nozzle described in the above embodiment is applied to a 1.8 million tons / year catalytic cracking unit. The processing capacity of a single nozzle is 35 t / h. The preheating temperature of the feed oil (atmospheric residue) is 180°C, the feed oil inlet pressure is 0.6 MPa, the atomizing steam consumption is 1400 kg / h, the atomizing steam inlet pressure is 0.7 MPa, the catalytic cracking reactor temperature is 550°C, the pressure is 0.2 MPa, and the feed oil mist particle size is about 30 μm. This improves the contact between the feed oil and the catalyst and optimizes the product distribution of the catalytic cracking.

[0064] Example 2

[0065] A catalytic cracking feed atomizing nozzle, the atomizing nozzle includes a steam chamber 13, a premixing chamber 8, a dispersion chamber 6 and a nozzle 1 that are connected in sequence and coaxially arranged. The steam chamber 13 is connected to an atomizing steam inlet 11. A fixed plate 10 is provided between the steam chamber 13 and the premixing chamber 8. The fixed plate 10 is provided with a plurality of through holes, and an air distribution pipe 5 is fixedly connected to the through holes. A tangential raw oil inlet 9 is provided on the outside of the premixing chamber 8. A spiral plate 7 is provided in the premixing chamber 8 along the axial direction. The air distribution pipe 5 passes through the spiral plate 7 and extends to the dispersion chamber 6. A dispersion structure is provided in the dispersion chamber 6.

[0066] In this embodiment, the angle between the spiral plate 7 and the axis of the premixing chamber 8 is set to β, and β=60°.

[0067] In this embodiment, if Figure 4 As shown, the dispersed structure is composed of a reduced diameter section 4, a straight pipe section 3 and an expanded diameter section 2 that are connected in sequence and coaxially arranged. The taper of the expanded diameter section 2 is 8°, and the taper of the reduced diameter section 4 is 12°. The dispersed structure is arranged in 9 groups.

[0068] In this embodiment, if Figure 4 As shown, the diameter of the straight pipe section ⅠⅠ32 is twice the diameter of the straight pipe section Ⅰ31, and the diameter of the large-diameter end of the reduced diameter section ⅠⅠ42 is twice the diameter of the large-diameter end of the reduced diameter section Ⅰ41; the reduced diameter section Ⅰ, straight pipe section Ⅰ, and expanded diameter section Ⅰ are set in 5 groups, and the reduced diameter section ⅠⅠ, straight pipe section ⅠⅠ, and expanded diameter section ⅠⅠ are set in 4 groups.

[0069] In this embodiment, the tangential feedstock oil inlet 9 is rectangular, and the angle between the tangential feedstock oil inlet 9 and the axis of the premixing chamber 8 is set to α, and α=60°.

[0070] In this embodiment, the starting position of the spiral plate 7 is set at the front end of the tangential raw oil inlet 9, and the ending position is set at the end of the air distribution pipe 5 away from the fixed plate 10; the rotation direction of the spiral plate 7 is consistent with the direction in which the raw oil flows to the dispersion chamber 6 after entering the premixing chamber 8, and a number of balancing holes are provided on the spiral plate 7.

[0071] In this embodiment, the gas distribution pipe 5 is a microporous tube, and the microporous tube is a ceramic powder sintered tube.

[0072] In this embodiment, the micropore diameter of the microporous tube is 200 μm, and the wall thickness of the microporous tube is 12 mm.

[0073] In this embodiment, the opening shape of the nozzle 1 is a slit with arc-shaped edges.

[0074] In this embodiment, the cavity between the nozzle 1 and the expanded diameter section 2 forms a remixing chamber 12 .

[0075] The fixed connection described in the present invention is a flange connection or the like.

[0076] The nozzle described in the above embodiment is applied to a 1.4 million tons / year catalytic cracking unit. The processing capacity of a single nozzle is 30 t / h. The preheating temperature of the feed oil (vacuum residue) is 210°C, the feed oil inlet pressure is 0.6 MPa, the atomizing steam consumption is 1200 kg / h, the atomizing steam inlet pressure is 0.7 MPa, the catalytic cracking reactor temperature is 540°C, the pressure is 0.23 MPa, and the feed oil mist particle size is about 35 μm. This improves the contact between the feed oil and the catalyst and optimizes the product distribution of the catalytic cracking.

[0077] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A catalytic cracking feed atomizing nozzle, characterized in that: The atomizing nozzle comprises a steam chamber (13), a premixing chamber (8), a dispersion chamber (6) and a nozzle (1) which are connected in sequence and coaxially arranged. The steam chamber (13) is connected to an atomizing steam inlet (11). A fixed plate (10) is provided between the steam chamber (13) and the premixing chamber (8). The fixed plate (10) is provided with a plurality of through holes. An air distribution pipe (5) is fixedly connected to the through holes. A tangential raw oil inlet (9) is provided on the outside of the premixing chamber (8). A spiral plate (7) is provided in the premixing chamber (8) along the axial direction. The air distribution pipe (5) passes through the spiral plate (7) and extends to the dispersion chamber (6). A dispersion structure is provided in the dispersion chamber (6). The starting position of the spiral plate (7) is set at the front end of the tangential raw oil inlet (9), and the ending position is set at the end of the gas distribution pipe (5) away from the fixed plate (10); the rotation direction of the spiral plate (7) is consistent with the direction of the raw oil flowing to the dispersion chamber (6) after entering the premixing chamber (8), and the spiral plate (7) is provided with a plurality of balancing holes; The dispersed structure is composed of a diameter-reducing section (4), a straight pipe section (3), and a diameter-expanding section (2) that are sequentially connected and coaxially arranged, the taper of the diameter-expanding section (2) and the diameter-reducing section (4) being 4°-15°, and at least one group of the dispersed structure is provided; The air distribution pipe (5) is a microporous pipe, the micropore diameter of the microporous pipe is 50-1000 μm, and the wall thickness of the microporous pipe is 5-20 mm.

2. A catalytic cracking feed atomizing nozzle according to claim 1, characterized in that: The angle between the spiral plate (7) and the axis of the premixing chamber (8) is set to β, and β=5°-60°.

3. A catalytic cracking feed atomizing nozzle according to claim 1, characterized in that: The tangential feedstock oil inlet (9) is circular or rectangular, and the angle between the tangential feedstock oil inlet (9) and the axis of the premixing chamber (8) is set to α, and α=30°-90°.

4. A catalytic cracking feed atomizing nozzle according to claim 1, characterized in that: The opening shape of the nozzle (1) is a slit shape.

5. A catalytic cracking feed atomizing nozzle according to claim 1, characterized in that: The cavity between the nozzle (1) and the expanded diameter section (2) forms a remixing chamber (12).

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