CN115889016A - Heavy oil catalytic cracking feeding atomizing nozzle - Google Patents

Abstract

The invention discloses a heavy oil catalytic cracking feeding atomizing nozzle which comprises a steam cavity, a premixing cavity, a venturi tube and a nozzle, wherein the steam cavity, the premixing cavity, the venturi tube and the nozzle are sequentially communicated and coaxially arranged, the steam cavity is communicated with an atomizing steam inlet, a fixing plate is arranged between the steam cavity and the premixing cavity, a plurality of through holes are formed in the fixing plate, a gas distribution pipe is fixedly connected onto the through holes, a tangential raw oil inlet is formed in the outer side of the premixing cavity, a spiral plate is arranged in the premixing cavity along the axial direction, the gas distribution pipe penetrates through the spiral plate, and at least two of the gas distribution pipes extend to the tail end of a diameter expansion section of the venturi tube. The invention provides a heavy oil catalytic cracking feeding atomizing nozzle, which can realize multi-stage atomization of heavy oil, effectively eliminate large-diameter liquid drops, obviously improve the size distribution of oil mist drops sprayed from the nozzle, further improve the contact between the obtained oil and a catalyst and optimize the distribution of catalytic cracking products.

Description

Heavy oil catalytic cracking feeding atomizing nozzle

Technical Field

The invention belongs to the technical field of catalytic cracking devices, and particularly relates to a heavy oil catalytic cracking feeding atomizing nozzle.

Background

The raw oil feeding atomizing nozzle is an important device of a catalytic cracking device in the field of petroleum refining, and has the following functions: raw oil is crushed and atomized into a large number of fine liquid drops, and the atomized raw oil drops are sprayed into a catalytic cracking riser reactor to be mixed and reacted with a catalyst in the riser reactor. In the catalytic cracking (FCC) process, the quality of the feed nozzle performance plays an important role in the cracking reaction and product distribution. The contact of the well atomized raw material and the high-temperature catalyst can quickly vaporize the raw material oil, reduce the formation of a 'wet catalyst' (unvaporized oil is adhered to the surface of the catalyst), improve the product distribution, reduce the coking phenomenon in a catalytic cracking reaction-regeneration system and bring considerable economic benefit.

Currently, catalytic cracking feed nozzles are broadly classified into the following categories: 1. the throat type atomizing nozzle improves the relative speed of gas and liquid by utilizing a contraction-expansion throat and realizes the atomization of raw materials by depending on the speed difference of gas phase and liquid phase; 2. the target type nozzle has the advantages that raw materials vertically impact a metal target under the action of high pressure, and then are atomized for the first time under the action of transverse airflow to form gas-liquid two-phase flow, and then are accelerated at the outlet of the nozzle to realize secondary atomization, the atomization effect of the nozzle is good, but higher feeding pressure and more atomization media are needed, the energy consumption is higher, and the equipment and the operation cost are higher; 3. the swirl nozzle is used for realizing primary atomization by quickly whirling a gas-liquid mixture in a gas-liquid two-phase cyclone and then realizing secondary atomization at a nozzle opening; 4. the high-pressure atomized steam is injected into flowing raw oil through a plurality of small holes to enable the raw material to contain a large amount of bubbles to form uniform bubble flow, and the bubbles are used as power to realize the atomization of the raw material by utilizing the generation, movement and deformation of the bubbles until the bubbles are sprayed out from a nozzle outlet and burst. The various nozzles have the problems of large atomizing particle size, high spraying speed, non-uniform atomization, high energy consumption and the like.

Patent 201610537088.X discloses a pretreatment method of catalytic raw oil, which comprises dispersing emulsified water into raw oil by an emulsifying tube (pore diameter of 1-60000 nm) for water-in-oil emulsification, making the particle size of oil drop in the obtained emulsified raw oil less than 50 μm, and spraying out via a nozzle to effectively atomize the raw oil. And the patent increases the pretreatment process of raw oil and increases the equipment investment.

Based on the problems, the invention provides a heavy oil feeding atomizing nozzle, which aims to solve the problems of large atomizing particle size, non-uniform atomization, high spraying speed, high energy consumption and the like of the existing nozzle.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a heavy oil catalytic cracking feeding atomizing nozzle which can realize multi-stage atomization of raw oil, effectively eliminate large-diameter liquid drops, obviously improve the size distribution of raw oil fog drops sprayed from the nozzle, further improve the contact between the raw oil and a catalyst and optimize the distribution of catalytic cracking products.

In order to achieve the purpose, the invention provides the following technical scheme:

the utility model provides a heavy oil catalytic cracking feeding atomizing nozzle, atomizing nozzle is including the steam chamber, the premixing chamber, venturi and the spout that communicate in proper order and coaxial setting, the steam chamber is linked together with the atomizing steam entry, be equipped with the fixed plate between steam chamber and the premixing chamber, a plurality of through-holes have been seted up on the fixed plate, fixedly connected with gas distribution pipe on the through-hole, the premixing chamber outside is provided with tangential raw oil entry, be provided with the spiral plate on the axis direction in the premixing chamber, the gas distribution pipe runs through the spiral plate, at least two among the gas distribution pipe extend to venturi's hole enlargement section is terminal.

Preferably, the included angle between the spiral plate and the axis of the premixing cavity is set to be beta, and the beta = 5-60 degrees.

Preferably, the Venturi tube consists of a reducing section, a straight tube section and an expanding section from right to left, and the taper of the expanding section and the reducing section is 4-15 degrees.

Preferably, the raw oil inlet is circular or rectangular, an included angle between the raw oil inlet and the axis of the premixing cavity is set to be alpha, and the alpha = 30-90 degrees.

Preferably, the starting position of the spiral plate is arranged at the front end of the raw oil inlet, and the ending position is arranged at one end of the gas distribution pipe far away from the fixing plate; the rotating direction of the spiral plate is consistent with the direction of the raw oil flowing to the Venturi tube after entering the premixing cavity, and a plurality of balance holes are formed in the spiral plate.

Preferably, the gas distribution pipe is a microporous pipe, the aperture of the microporous pipe is 100-1000 μm, and the pipe wall thickness of the microporous pipe is 5-20mm.

Preferably, the cavity between the nozzle and the expanding section forms a remixing chamber.

The invention also protects the application of the heavy oil catalytic cracking feed atomizing nozzle in heavy oil catalytic cracking.

Compared with the prior art, the invention has the following beneficial effects:

(1) According to the heavy oil catalytic cracking feeding atomizing nozzle, micro-nano bubbles are quickly and uniformly dispersed into raw oil through the arrangement of the gas distribution pipe and the spiral plate in the premixing cavity, the raw oil and atomizing steam are quickly and uniformly mixed, a gas-liquid mixture uniformly dispersed with the atomizing steam enters the reducing section, the straight pipe section and the expanding section of the Venturi tube, then a gas-liquid two phase is uniformly mixed again, and the mixture is sprayed out from a nozzle after passing through a remixing chamber; the comprehensive action of the gas distribution pipe, the spiral plate, the Venturi tube and the remixing chamber greatly enhances the atomization effect of the nozzle, and the atomized particle size (the mean particle size and mass median diameter) of the raw oil reaches about 30 mu m.

(2) According to the heavy oil catalytic cracking feeding atomizing nozzle, the tangential raw oil inlet and the spiral plate are arranged, so that raw oil enters the premixing cavity in a spiral mode, the raw oil is acted by the surface tension and the external force of the raw oil, when the flow rate of the raw oil reaches a certain value, the external force of the raw oil is larger than the surface tension, a large number of liquid drops are thrown out of the spiral plate and the periphery of a raw oil main body, and the primary dispersion of the raw oil is achieved; micro-nano-level small bubbles are vertically injected into the raw oil through the arrangement of the air distribution pipe and the spiral plate, so that the raw oil is impacted, and the secondary dispersion of the raw oil is realized; the raw oil with uniformly dispersed small bubbles enters the reducing section, the gas-liquid two-phase speed is increased along with the flow of the bubbles entering the reducing section, the spiral action is increased, the raw oil is spread into a film under the spiral action, the surface area of the raw oil is increased, and the tertiary dispersion of the raw oil is realized; the gas-liquid mixture continues to flow forwards, and in the straight pipe section, the atomized steam has strong tearing and shearing effects on the raw oil due to the gas-liquid two-phase speed difference, so that the four-time dispersion of the raw oil is realized. Meanwhile, when the gas-liquid mixture passes through the straight pipe section, the atomized steam is compressed, and when the atomized steam flows into the diameter expanding section from the straight pipe section, the atomized steam expands in volume to extrude the raw oil, so that the dispersion effect of the atomized steam on the raw oil is increased again; the gas-liquid mixture flows out of the diameter expanding section and then enters the remixing chamber to be mixed, the gas-liquid mixture is uniformly mixed and then is sprayed out of the nozzle through the nozzle, and because the external environment pressure of the nozzle is lower than the internal pressure of the nozzle, the small-bubble atomizing steam rapidly expands and breaks at the nozzle of the nozzle to break the raw oil into liquid drops, the five-time dispersion of the raw oil is realized, and the raw oil is atomized. Meanwhile, the gas distribution pipes extending to the reducing section, the straight pipe section and the expanding section of the whole Venturi pipe continuously supply gas, so that the gas-liquid mixing rate in the reducing section is accelerated, and the raw oil is dispersed more uniformly. The raw oil is dispersed and mixed for five times, the size distribution of the fog drops of the raw oil is obviously improved, the contact between the raw oil and a catalyst is further improved, and the product distribution of catalytic cracking is optimized.

(3) According to the heavy oil catalytic cracking feeding atomizing nozzle provided by the invention, raw oil enters a premixing cavity through a raw oil inlet and a spiral plate, atomized steam enters the premixing cavity through a gas distribution pipe, the spiral plate enables the raw oil to move tangentially along a straight section and is vertical to the direction of the atomized steam from the gas distribution pipe, the vertical cutting action of the raw oil on the atomized steam promotes the formation of micro-nano small bubbles, and then the atomized steam is uniformly and rapidly dispersed in the raw oil; meanwhile, the arrangement of the spiral plate increases the movement track of the gas-liquid mixture in the premixing cavity, so that the residence time of the gas-liquid mixture in the premixing cavity is prolonged, the sufficient mixing of atomized steam and raw oil in the premixing cavity is facilitated, the disturbance between the gas-liquid mixture is increased due to the arrangement of the spiral plate, the mixing between the atomized steam and the raw oil is facilitated, and small bubbles are more uniformly dispersed into the raw oil to form uniform bubble flow.

(4) According to the heavy oil catalytic cracking feeding atomizing nozzle provided by the invention, a large amount of micro-nano-scale small bubbles are quickly and uniformly dispersed into raw oil through the arrangement of the porous pipe and the spiral plate, the micro-nano-scale bubbles are formed, the number of bubbles of atomized steam with the same volume is increased, the surface area of the atomized steam is increased, and the gas-liquid contact area is enlarged, so that the shearing action of the atomized steam on the raw oil and the impact action of the atomized steam explosion on the raw oil are enhanced, and the atomizing effect of the nozzle is enhanced.

(5) According to the heavy oil catalytic cracking feeding atomizing nozzle provided by the invention, due to the formation of the micro-nano bubbles and the uniform mixing of the micro-nano bubbles and the raw oil, the effect of the atomized steam with the same volume is more obvious, so that the consumption of the atomized steam can be properly reduced, and the spraying speed of the raw oil is further reduced.

Drawings

FIG. 1 is a schematic structural view of a heavy oil catalytic cracking feed atomizing nozzle of the present invention;

FIG. 2 is a schematic view of a tangential feed oil inlet of the present invention;

FIG. 3 is a schematic view of a beveled feed oil inlet according to the present invention;

FIG. 4 is a schematic structural view of the gas distribution pipe and the spiral plate inside the gas-liquid mixing chamber according to the present invention;

wherein, 1, a nozzle; 2. a remixing chamber; 3. a venturi tube; 4. a diameter expanding section; 5. a straight pipe section; 6. a reducing section; 7. an air distribution pipe; 8. a premix chamber; 9. a raw oil inlet; 10. a fixing plate; 11. a spiral plate; 12. an atomizing steam inlet; 13. a steam chamber.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. indicate an orientation or a positional relationship based on that shown in the drawings or that the product of the present invention is used as it is, this is only for convenience of description and simplification of the description, and it does not indicate or imply that the device or the element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention.

Furthermore, the appearances of the terms "first," "second," and the like, if any, are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

It should be noted that the features of the embodiments of the present invention may be combined with each other without conflict.

As shown in fig. 1 and 4, the atomizing nozzle for the heavy oil catalytic cracking feed comprises a steam cavity 13, a premixing cavity 8, a venturi tube 3 and a nozzle 1 which are sequentially communicated and coaxially arranged, wherein the steam cavity 13 is communicated with an atomizing steam inlet 12, a fixing plate 10 is arranged between the steam cavity 13 and the premixing cavity 8, a plurality of through holes are formed in the fixing plate 10, a gas distribution pipe 7 is fixedly connected to the through holes, a tangential raw oil inlet 9 is formed in the outer side of the premixing cavity 8, a spiral plate 11 is arranged in the premixing cavity 8 along the axial direction, the gas distribution pipe 7 penetrates through the spiral plate 11, and at least two of the gas distribution pipes 7 extend to the tail end of an expanding section 4 of the venturi tube 3.

In some embodiments, the angle between the spiral plate 11 and the axis of the premix chamber 8 is set to β, and β =5 ° -60 °, which may be 5 °, 10 °, 15 °, 20 °, 25 °, 30 °, 35 °, 40 °, 45 °, 50 °, 55 °, 60 °, preferably 45 °.

Specifically, the spiral plate is arranged, the gas-liquid mixture enters the diameter reduction section to continue to carry out spiral motion, meanwhile, the motion sectional area is reduced, the gas-liquid two-phase speed is increased, the spiral action is increased, the raw oil is spread into a film under the spiral action, the surface area of the raw oil is increased, and the atomization quality of the raw oil is enhanced.

In some embodiments, the venturi tube 3 is composed of a reduced diameter section 6, a straight tube section 5 and an expanded diameter section 4 from right to left, and the tapers of the expanded diameter section 4 and the reduced diameter section 6 are 4 ° to 15 °, and may be 4 °, 5 °, 6 °, 7 °, 8 °, 9 °, 10 °, 11 °, 12 °, 13 °, 14 °, 15 °, and preferably 7 °.

In some embodiments, as shown in fig. 2 and fig. 3, the raw oil inlet 9 is circular or rectangular, an included angle between the raw oil inlet 9 and the axis of the premixing chamber 8 is set as α, and α =30 ° -90 °, which may be 30 °, 35 °, 40 °, 45 °, 50 °, 55 °, 60 °, 65 °, 70 °, 75 °, 80 °, 85 °, 90 °, and preferably 45 °.

In some embodiments, as shown in fig. 4, the starting position of the spiral plate 11 is disposed at the front end of the raw oil inlet 9, and the ending position is disposed at one end of the air distribution pipe 7 away from the fixing plate 10; the rotating direction of the spiral plate 11 is consistent with the direction of the venturi tube 3 after raw oil enters the premixing cavity 8, and a plurality of balance holes are formed in the spiral plate 11.

In some embodiments, the gas distribution tube 7 is a microporous tube, which may be one of a sintered metal powder microporous tube or a ceramic powder sintered tube.

Specifically, the arranged microporous tube can enable atomized steam entering the premixing cavity to form micro-nano bubbles, and then the atomized steam can be uniformly and rapidly dispersed in the raw oil.

In some embodiments, the microporous tube has a pore size of 100-1000 μm, and may be 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, preferably 200 μm; the wall thickness of the microporous tube is 5-20mm, and can be 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, preferably 10mm.

In some embodiments, the cavity between the spout 1 and the expanded diameter section 4 forms a remixing chamber 12.

The fixed connection can be welding, thread or flange connection and the like.

The working principle of the heavy oil catalytic cracking feeding atomizing nozzle provided by the invention is as follows: raw oil enters the premixing cavity 8 through the raw oil inlet 9 and the spiral plate 11 in a spiral mode, the raw oil makes spiral motion, a large number of liquid drops are thrown out of the peripheries of the spiral plate 11 and the raw oil main body, and primary dispersion of the raw oil is achieved. The atomized steam forms micro-nano-scale small bubbles through the atomized steam inlet 12, the air distribution pipe 7 and the spiral plate 11 and then is vertically injected into the raw oil to impact the raw oil, so that the secondary dispersion of the raw oil is realized. Meanwhile, the micro-nano holes in the gas distribution pipe 7 and the spiral plate 11 promote the formation of micro-nano bubbles, and the small bubbles are uniformly and quickly dispersed into the raw oil due to the arrangement of the spiral plate 11 in the premixing cavity 8. The gas-liquid mixture is spirally mixed in the premixing cavity 8, small bubbles uniformly enter the raw oil, then the gas-liquid mixture uniformly enters the diameter-reducing section 6, the gas-liquid two-phase speed is increased, the spiral effect is increased, the raw oil is spread into a film under the spiral effect, the surface area of the raw oil is increased, and the tertiary dispersion of the raw oil is realized. Then the gas-liquid mixture enters the straight pipe section 5, gas-liquid two phases move in an accelerated manner at the straight pipe section 5, and the raw oil is broken into very small liquid drops by the atomized steam due to the speed difference between the gas phase and the liquid phase to form gas-liquid two-phase atomized flow, so that the four-time dispersion of the raw oil is realized; moreover, because the gas distribution pipe 7 extends to the tail end of the expanding section, the gas distribution pipe continuously admits gas when the gas-liquid two-phase liquid is dispersed, thereby ensuring the mixing efficiency and the mixing uniformity of the gas-liquid two-phase liquid in the Venturi tube and enabling the gas to be more uniformly dispersed in the raw oil; the gas-liquid two-phase atomized flow enters the remixing chamber 2 through the expanding section 4, the gas-liquid mixture is uniformly mixed again and then is sprayed out of the nozzle through the nozzle 1, small bubbles mixed in the raw oil rapidly expand and break at the nozzle 1 to break the raw oil into liquid drops, five times of dispersion is realized, and the raw oil is atomized.

Example 1

As figure 1, a heavy oil catalytic cracking feeding atomizing nozzle, atomizing nozzle is including the steam chamber 13, the premixing chamber 8, venturi 3 and the spout 1 that communicate in proper order and coaxial setting, steam chamber 13 is linked together with atomizing steam inlet 12, be equipped with fixed plate 10 between steam chamber 13 and the premixing chamber 8, a plurality of through-holes have been seted up on the fixed plate 10, fixedly connected with gas distribution pipe 7 on the through-hole, the premixing chamber 8 outside is provided with tangential raw oil inlet 9, be provided with spiral plate 11 in the premixing chamber 8 on the axis direction, gas distribution pipe 7 runs through spiral plate 11, four gas distribution pipe 7 extends to venturi 3's diameter expansion section 4 is terminal, and other gas distribution pipes 7 extend the front end of venturi 3's diameter reduction section 6.

In the present embodiment, the included angle between the spiral plate 11 and the axis of the premix chamber 8 is set to β, and β =45 °.

In the present embodiment, as shown in fig. 3, the venturi tube 3 is composed of a diameter-reduced section 6, a straight tube section 5 and an diameter-expanded section 4 from right to left, and the taper of the diameter-expanded section 4 and the taper of the diameter-reduced section 6 are both 10 °.

In this embodiment, the raw oil inlet 9 is circular, an included angle between the raw oil inlet 9 and an axis of the premixing cavity 8 is set to α, and α =45 °.

In this embodiment, the starting position of the spiral plate 11 is disposed at the front end of the raw oil inlet 9, and the ending position is disposed at one end of the air distribution pipe 7 far away from the fixing plate 10; the direction of rotation of spiral plate 11 and the flow direction of raw oil flow to behind the entering premixing chamber 8 venturi 3's direction is unanimous, be equipped with a plurality of balancing holes on the spiral plate 11.

In this embodiment, the gas distribution pipe 7 is a microporous pipe, and the microporous pipe is a sintered metal powder microporous pipe.

In this embodiment, the pore diameter of the microporous tube is 200 μm, and the wall thickness of the microporous tube is 10mm.

In the present embodiment, the opening of the spout 1 has a slit shape.

In this embodiment, the cavity between the nozzle 1 and the expanded diameter section 4 forms a remixing chamber 12.

In this embodiment the fixed connection is a weld.

The nozzle described in the above embodiment is applied to a catalytic cracking device of 180 ten thousand tons/year, the treatment capacity of a single nozzle is 35t/h, the preheating temperature of heavy oil (atmospheric residue) is 180 ℃, the inlet pressure of the heavy oil is 0.6MPa, the consumption of atomized steam is 1400kg/h, the inlet pressure of the atomized steam is 0.7MPa, the temperature of a catalytic cracking reactor is 550 ℃, the pressure is 0.2MPa, and the atomized particle size of the heavy oil is about 30 μm, so that the contact between the heavy oil and the catalyst is improved, and the distribution of products of catalytic cracking is optimized.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (8)

1. The utility model provides a heavy oil catalytic cracking feeding atomizing nozzle, characterized in that, atomizing nozzle is including steam chamber (13), pre-mixing chamber (8), venturi (3) and spout (1) that communicate in proper order and coaxial setting, steam chamber (13) are linked together with atomizing steam inlet (12), be equipped with fixed plate (10) between steam chamber (13) and pre-mixing chamber (8), a plurality of through-holes have been seted up on fixed plate (10), fixedly connected with gas distribution pipe (7) on the through-hole, the pre-mixing chamber (8) outside is provided with tangential raw oil entry (9), be provided with spiral plate (11) along the axis direction in pre-mixing chamber (8), gas distribution pipe (7) run through spiral plate (11), at least two in gas distribution pipe (7) extend to the diameter expansion section (4) end of venturi (3).

2. A heavy oil catalytic cracking feed atomizing nozzle according to claim 1, characterized in that the included angle between the spiral plate (11) and the axis of the premixing chamber (8) is set to be β, and β =5 ° to 60 °.

3. A heavy oil catalytic cracking feed atomizing nozzle according to claim 1, characterized in that said venturi tube (3) is composed of a reducing section (6), a straight tube section (5) and an expanding section (4) from right to left, and the taper of said expanding section (4) and reducing section (6) is 4 ° to 15 °.

4. A heavy oil catalytic cracking feed atomizing nozzle as claimed in claim 1, wherein said raw oil inlet (9) is circular or rectangular, and the angle between said raw oil inlet (9) and the axis of the premixing chamber (8) is set to α, and α =30 ° -90 °.

5. A heavy oil catalytic cracking feed atomizing nozzle according to claim 2, characterized in that the starting position of the spiral plate (11) is arranged at the front end of the raw oil inlet (9), and the ending position is arranged at the end of the gas distribution pipe (7) far away from the fixed plate (10); the rotating direction of the spiral plate (11) and the flowing direction of raw oil flowing to the premixing cavity (8) are consistent, and a plurality of balance holes are formed in the spiral plate (11).

6. The feed atomizing nozzle for catalytic cracking of heavy oil according to claim 1, wherein the gas distribution pipe (7) is a microporous pipe, the pore diameter of the microporous pipe is 100-1000 μm, and the wall thickness of the microporous pipe is 5-20mm.

7. A heavy oil catalytic cracking feed atomizing nozzle according to claim 1, characterized in that the cavity between the nozzle orifice (1) and the expanding diameter section (4) forms a remixing chamber (2).

8. Use of the heavy oil catalytic cracking feed atomizing nozzle of any one of claims 1 to 7 in heavy oil catalytic cracking.

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