Double-nozzle downer reaction device

Abstract

The utility model discloses a double-nozzle downer reaction device, which belongs to the technical field of petrochemical engineering and comprises a downer reactor, two oil nozzles are arranged at the bottom of the downer reactor, and each oil nozzle is connected with a respective pipeline and independently controls the flow and speed of each nozzle; the top of the downer reactor is provided with a cyclone discharge port, the cyclone discharge port is connected with a first cyclone separator, the upper end of the first cyclone separator is connected with one end of a riser reactor, and the other end of the riser reactor is connected with a second settler. The double oil nozzles capable of independently controlling flow and speed are arranged at the bottom of the downer reactor, so that gas in the reactor is distributed more uniformly, local overhigh flow velocity is reduced, blockage and abrasion in the reactor are reduced, local hot spots and dead zones are reduced, and heat transfer and mass transfer effects are enhanced. And the riser reactor is additionally arranged, so that the separated oil gas is further subjected to catalytic reaction, and insufficient catalytic reaction depth in the downer reactor is prevented.

Description

Technical Field

[0001] This utility model belongs to the field of petrochemical technology, specifically relating to a dual-nozzle downward bed reactor. Background Technology

[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.

[0003] In the experimental unit for crude oil catalytic cracking to olefins, a parallel rising bed reactor with high and low pressures is used. The feedstock oil comes into contact with the hot catalyst in the riser reactor and reacts rapidly. Then, the reaction products and catalyst are separated in a settling tank and a cyclone separator. However, in actual operation, due to the upward flow of the catalyst and feedstock oil, some backmixing occurs.

[0004] Patent CN117384663A discloses a method and system for producing low-carbon olefins and aromatics by descending bed catalytic cracking. By setting a swirl inlet distributor and an oil nozzle at the lower end of the descending bed reactor, the feed oil is directed upward to react with the catalyst, thereby reducing backmixing.

[0005] However, the above solution still has some problems:

[0006] 1. The design of a single oil nozzle on the side results in excessively high flow velocities in some areas of the reactor, which leads to uneven gas distribution within the reactor and is prone to localized blockage and wear, as well as localized hot spots and dead zones.

[0007] 2. After oil and gas separation, the reaction in the downflow bed reactor is directly fed into the fractionation system. However, compared with the riser reactor, the catalyst concentration in the downflow bed reactor is lower, resulting in insufficient catalytic reaction depth in some reactions. Utility Model Content

[0008] To address the aforementioned problems, this invention provides a dual-nozzle downflow bed reactor. Dual oil nozzles are installed at the bottom of the downflow bed reactor, and the flow rate and velocity of each nozzle are independently controlled to improve gas distribution within the reactor. Furthermore, by adding a riser reactor, the separated oil and gas undergo further catalytic reaction, preventing insufficient catalytic reaction depth within the downflow bed reactor.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A dual-nozzle descending bed reactor includes a descending bed reactor with two oil nozzles at the bottom of the reactor. Each oil nozzle is connected to its own pipeline, and the flow rate and velocity of each nozzle are independently controlled.

[0011] A cyclone outlet is provided at the top of the descending bed reactor. The cyclone outlet is connected to the first cyclone separator through the first pipeline. The upper end of the first cyclone separator is connected to one end of the riser reactor, and the other end of the riser reactor is connected to the second settler.

[0012] Preferably, a catalyst inlet distributor is provided at the top of the downward bed reactor, and the upper end of the catalyst inlet distributor is connected to the first fluidizing medium pipeline.

[0013] Preferably, the bottom of the downflow bed reactor is connected to a multi-tube cyclone inlet distributor, and a second fluidizing medium pipeline is connected below the multi-tube cyclone inlet distributor.

[0014] Preferably, the lower end of the first cyclone separator is connected to the first stripper via a second pipeline; the lower end of the first stripper is connected to the first stripping steam pipeline.

[0015] Preferably, the upper end of the first stripper is connected to the first cyclone separator via a third pipeline; the bottom of the first stripper is connected to the riser regenerator via a fourth pipeline.

[0016] Preferably, a second stripper is provided at the bottom of the second settling tank, the lower end of the second stripper is connected to a second stripping steam pipeline, and the second stripper is connected to the riser regenerator through a seventh pipeline.

[0017] Preferably, the bottom end of the riser regenerator is connected to the regeneration medium pipeline; the top end of the riser regenerator is connected to the second cyclone separator and is installed in the first settling tank.

[0018] Preferably, a third cyclone separator is also provided at the top of the first settling device, and the top of the third cyclone separator is connected to the flue gas outlet pipeline.

[0019] Preferably, the first settler is connected to the catalyst inlet distributor via a fifth pipeline and to the riser reactor via a sixth pipeline.

[0020] Preferably, the fourth, fifth, sixth, and seventh pipelines are all equipped with slide valves.

[0021] Compared with the prior art, the advantages and positive effects of this utility model are:

[0022] This invention, by setting dual oil nozzles at the bottom of the downward-flowing bed reactor, and allowing independent control of the flow rate and velocity of each nozzle, enables more uniform gas distribution within the reactor, reduces excessively high local flow velocities, minimizes internal blockage and wear, reduces local hot spots and dead zones, and enhances heat and mass transfer.

[0023] This invention adds a riser reactor to further catalyze the separated oil and gas, preventing insufficient catalytic reaction depth in the downflow reactor. Furthermore, the catalysts from both steps are ultimately regenerated in the riser regenerator, enabling the catalysts to be recycled. Attached Figure Description

[0024] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0025] Figure 1 This is a schematic diagram of the connections of various structures of the device according to an embodiment of the present utility model;

[0026] In the picture:

[0027] 1. Downward-flowing bed reactor; 2. Oil nozzle; 3. Multi-tube cyclone inlet distributor; 4. Second fluidizing medium pipeline; 5. Cyclone outlet; 6. Catalyst inlet distributor; 7. First fluidizing medium; 8. First pipeline; 9. First cyclone separator; 10. Second pipeline; 11. First stripper; 12. First stripping steam pipeline; 13. Third pipeline; 14. Fourth pipeline; 15. Riser regenerator; 16. Regeneration medium pipeline; 17. Second cyclone separator; 18. First settling tank; 19. Third cyclone separator; 20. Fifth pipeline; 21. Sixth pipeline; 22. Second settling tank; 23. Riser reactor; 24. Second stripper; 25. Second stripping steam pipeline; 26. Seventh pipeline. Detailed Implementation

[0028] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0029] The present invention will now be described in detail with reference to the accompanying drawings. This embodiment discloses a dual-nozzle downward bed reactor, such as... Figure 1As shown, the reactor includes a descending bed reactor 1. A catalyst inlet distributor 6 is installed at the top of the descending bed reactor 1. The upper opening of the catalyst inlet distributor 6 is connected to a pipeline for a first fluidizing medium 7. The first fluidizing medium 7 mixes with the catalyst and flows into the descending bed reactor 1. Two oil nozzles 2 are installed at the bottom of the descending bed reactor 1, each connected to its own pipeline for spraying feed oil into the bottom of the reactor 1. It is understood that the dual nozzles allow for independent control of the flow rate and velocity of each nozzle, providing greater flexibility for adjusting reaction conditions. Furthermore, the two oil nozzles can improve the gas distribution within the descending bed reactor, making the gas distribution more uniform, reducing excessively high local flow velocities, reducing internal blockage and wear, and minimizing local hot spots and dead zones, thereby enhancing heat and mass transfer.

[0030] The bottom of the downflow bed reactor 1 is connected to a multi-tube cyclone inlet distributor 3, and below the multi-tube cyclone inlet distributor 3 is a second fluidizing medium pipeline 4. The second fluidizing medium enters the multi-tube cyclone inlet distributor 3 through multiple parallel pipes, and after generating a rotating airflow in the multi-tube cyclone inlet distributor 3, it enters the bottom of the downflow bed reactor 1 and mixes with the feed oil, causing the upward-flowing feed oil to rotate and flow, making the feed oil and catalyst swirl countercurrent upwards, and carrying out the catalytic cracking reaction in the downflow bed reactor 1. The upward rotating flow of the feed oil contacts and collides with the catalyst to ensure that the catalyst participates more fully in the reaction, improving the uniformity and efficiency of the reaction.

[0031] Understandably, the dual-oil nozzle design can effectively increase the atomization of the feedstock oil, increase the contact area with the catalyst, and thus improve the yield of dienes in the product.

[0032] like Figure 1 As shown, the top of the descending bed reactor 1 is provided with a cyclone outlet 5, which is connected to the first cyclone separator 9 through the first pipeline 8. The upper end of the first cyclone separator 9 is connected to one end of the riser reactor 23, and the other end of the riser reactor 23 is connected to the second settler 22.

[0033] The lower end of the first cyclone separator 9 is connected to the first stripper 11 via the second pipeline 10. The oil and gas produced after the catalytic cracking reaction of the feed oil and the catalyst are discharged from the top of the descending bed reactor through the cyclone outlet 5, and then enter the first cyclone separator 9 for separation. The separated oil and gas enter the riser reactor 23 for further reaction, while the separated catalyst enters the first stripper 11 for stripping.

[0034] like Figure 1As shown, the lower end of the first stripper 11 is connected to the first stripping steam pipeline 12, and the upper end of the first stripper 11 is connected to the first cyclone separator 9 via the third pipeline 13. The bottom of the first stripper 11 is connected to the riser regenerator 15 via the fourth pipeline 14. The catalyst separated from the first cyclone separator 9 is stripped by stripping steam in the first stripper 11, and the stripped oil and gas re-enter the first cyclone separator 9 via the third pipeline; while the stripped catalyst enters the riser regenerator 15 via the fourth pipeline.

[0035] like Figure 1 As shown, the bottom end of the riser regenerator 15 is connected to the regeneration medium pipeline 16; the riser regenerator 15 is connected to the first settling tank 18. Specifically, the top end of the riser regenerator 15 is connected to the second cyclone separator 17 and is disposed in the first settling tank 18; a third cyclone separator 19 is also disposed on the top of the first settling tank 18, and the top end of the third cyclone separator 19 is connected to the flue gas outlet pipeline.

[0036] Understandably, after stripping, the catalyst enters the riser regenerator, where it undergoes coking regeneration by introducing a regeneration medium. The regenerated catalyst then enters the first settling tank, where it is separated from the flue gas and settles in the first settling tank under the action of the second cyclone separator. The resulting flue gas then passes through the third cyclone separator and is discharged from the flue gas outlet pipeline.

[0037] like Figure 1 As shown, the first settling tank 18 is connected to the catalyst inlet distributor 6 via the fifth pipeline 20, which is used to feed the regenerated catalyst into the catalyst inlet distributor 6; the first settling tank 18 is connected to the riser reactor 23 via the sixth pipeline 21, which feeds the regenerated catalyst into the riser reactor 23 and then reacts further with the separated oil and gas, thereby preventing insufficient reaction depth in the downbed reactor.

[0038] After the second reaction, the oil and gas, along with the catalyst, enter the second settling tank 22 for separation. The bottom of the second settling tank 22 is connected to the second stripper 24. The catalyst separated again enters the second stripper 24, while the separated oil and gas are sent to the fractionation system via the pipeline at the top of the second settling tank 22. The lower end of the second stripper is connected to the second stripping steam pipeline 25, and the second stripper is connected to the riser regenerator via the seventh pipeline 26. It can be understood that the catalyst separated again is stripped with stripping steam in the second stripper and then sent to the riser regenerator via the seventh pipeline for further coking and regeneration, thus forming a cycle.

[0039] Understandably, the fourth, fifth, sixth, and seventh pipelines are all equipped with slide valves to control the opening and closing of the pipelines.

[0040] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the scope of protection of the present utility model.

Claims

1. A dual-nozzle downward-flowing bed reactor, characterized in that, It includes a descending bed reactor, with two oil nozzles at the bottom of the reactor. Each oil nozzle is connected to its own pipeline, and the flow rate and speed of each nozzle are independently controlled. A cyclone outlet is provided at the top of the descending bed reactor. The cyclone outlet is connected to the first cyclone separator through the first pipeline. The upper end of the first cyclone separator is connected to one end of the riser reactor, and the other end of the riser reactor is connected to the second settler.

2. The dual-nozzle downward-flowing bed reactor as described in claim 1, characterized in that, A catalyst inlet distributor is installed at the top of the downward bed reactor, and the upper end of the catalyst inlet distributor is connected to the first fluidizing medium pipeline.

3. The dual-nozzle downward-flowing bed reactor as described in claim 1, characterized in that, The bottom of the downflow bed reactor is connected to a multi-tube cyclone inlet distributor, and a second fluidizing medium pipeline is connected below the multi-tube cyclone inlet distributor.

4. The dual-nozzle downward-flowing bed reactor as described in claim 1, characterized in that, The lower end of the first cyclone separator is connected to the first stripper via a second pipeline; the lower end of the first stripper is connected to the first stripping steam pipeline.

5. The dual-nozzle downward-flowing bed reactor as described in claim 4, characterized in that, The upper end of the first stripper is connected to the first cyclone separator via a third pipeline; the bottom of the first stripper is connected to the riser regenerator via a fourth pipeline.

6. The dual-nozzle downward-flowing bed reactor as described in claim 5, characterized in that, A second stripper is installed at the bottom of the second settling tank. The lower end of the second stripper is connected to a second stripping steam pipeline. The second stripper is connected to the riser regenerator through a seventh pipeline.

7. The dual-nozzle downward-flowing bed reactor as described in claim 5, characterized in that, The bottom end of the riser regenerator is connected to the regeneration medium pipeline; the top end of the riser regenerator is connected to the second cyclone separator and is installed in the first settling tank.

8. A dual-nozzle downward-flowing bed reactor as described in claim 7, characterized in that, A third cyclone separator is also installed at the top of the first settling device, and the top of the third cyclone separator is connected to the flue gas outlet pipeline.

9. A dual-nozzle downward-flowing bed reactor as described in claim 7, characterized in that, The first settling device is connected to the catalyst inlet distributor via the fifth pipeline and to the riser reactor via the sixth pipeline.

10. A dual-nozzle downward-flowing bed reactor as described in claim 9, characterized in that, The fifth, fourth, sixth, and seventh pipelines are all equipped with slide valves.

Images