A circulation system for protecting high-temperature pipelines by quenching and solidification

Abstract

The present invention provides a circulation system for protecting high-temperature pipelines by quenching and washing solids, comprising: a high-temperature pipeline, including a vertical pipeline and an inclined pipeline connected by an arc elbow; a washing device; provided with a product gas inlet, a product gas outlet, a washing water outlet and a flushing water replenishment port; a solid-liquid separation device, provided with a liquid inlet connected to the washing water outlet, a slurry discharge outlet and a liquid phase outlet; a deoxidation device; provided with an inlet connected to the liquid phase outlet, a water phase outlet and a gas phase outlet containing oxides; wherein a flushing nozzle for spraying water into the inside of the arc elbow is provided at the arc elbow, and a fan-shaped nozzle is provided on the inner wall of the inclined pipeline. The circulation system provided by the present invention is arranged through high-temperature pipelines and accessories, and the self-produced water introduced into the system is pressurized, divided into two parts of cooling and flushing, and then sent to the high-temperature pipeline to flush and cool the pipeline through the nozzle, so as to achieve the purpose of protecting the high-temperature pipeline and cleaning solid sediments.

Description

Technical Field

[0001] The invention relates to the technical field of chemical industry, and is particularly suitable for a circulation system for quenching and solid washing of product gas in coal chemical industry and methanol to hydrocarbon process in protecting high-temperature pipelines. Background Art

[0002] In the chemical industry, coal chemical industry, methanol chemical industry and catalytic cracking process often use fluidized bed technology as an important means to produce chemical products. It is also an important link in realizing the replacement of petroleum with other resources to produce hydrocarbons.

[0003] During each start-up of the fluidized bed reaction-regeneration system, during the process of adding catalyst, normal production, and shutting down to unload catalyst, fine catalyst powder particles smaller than a certain size will flow to the downstream cooling equipment along with the process or replacement medium in the product gas pipeline. In this process, the fine catalyst powder particles are easily combined with water in the process or replacement medium, agglomerated to form a mud-like substance, which is deposited at the bottom of the pipeline due to gravity. In the long run, there is a high risk of reducing the flux of the product gas pipeline, the weight of the deposited catalyst exceeding the bearing capacity of the pipeline, and damaging the equipment. When the blockage is serious, there is even a risk of causing overpressure in the upstream equipment, resulting in large fluctuations in production in the pipeline.

[0004] In addition, in the current fluidized bed reaction-regeneration system, in order to prevent the catalyst particles from wearing the high-temperature pipeline, the existing technology mostly adopts the method of setting a wear-resistant lining in the high-temperature pipeline, and the high-temperature medium in the pipeline often needs to be cooled and connected to a water cooling system such as a tower or tank at the end. The concentration of water vapor here is relatively high, and the catalyst combines, so the agglomeration effect of the muddy catalyst is most serious at the end of the high-temperature pipeline leading to the cooling system; further, the agglomerated muddy catalyst will aggravate the agglomeration, and the water content in the muddy catalyst will be converted into liquid water due to cooling and adsorbed in the lining. When the operation is started again, this part of the water will cause the lining to disintegrate due to high-temperature gasification, which will reduce the production operation cycle and increase the maintenance cost. When the lining is seriously damaged, it is easy to form a safety hazard. Summary of the invention

[0005] In order to overcome the problems existing in the prior art, the present invention circulates the reaction product gas of the methanol to hydrocarbons device or the reaction product gas of the catalytic cracking device to flush away the solid particles entrained in the high-temperature product gas, thereby protecting the high-temperature pipeline and reducing the safety hazards caused by blockage.

[0006] In order to achieve the purpose of the present invention, the present invention adopts the following technical solutions:

[0007] In the circulation system for protecting high-temperature pipeline quenching and solidification provided by the present invention, the circulation system comprises:

[0008] A high-temperature pipeline is used to transport the high-temperature gas containing solid particles to the washing device for washing; the high-temperature pipeline includes a vertical pipeline and an inclined pipeline connected to the vertical pipeline, the vertical pipeline and the inclined pipeline are connected through an arc elbow, a reaction product gas inlet is provided at the top of the vertical pipeline, a reaction product gas outlet is provided at the bottom of the inclined pipeline, and a cooling water spray port is provided at the upper part of the arc elbow for spraying water into the high-temperature pipeline to reduce the temperature;

[0009] A washing device for washing the high-temperature gas containing solid particles; the washing device is provided with a product gas inlet, a product gas outlet, a washing water outlet and a flushing water replenishment inlet which are connected to the reaction product gas outlet through a pipeline;

[0010] A solid-liquid separation device, wherein the solid-liquid separation device is provided with a liquid inlet, a slurry discharge outlet and a liquid phase outlet which are connected to the washing water outlet;

[0011] A deoxidation device, used for removing oxides from the liquid phase separated by the solid-liquid separation device; the deoxidation device is provided with an inlet connected to the liquid phase outlet, a water phase outlet and a gas phase outlet containing oxides;

[0012] Among them, a flushing nozzle for spraying water into the inside of the circular arc bend is provided at the circular arc bend pipe, and a fan-shaped nozzle is provided on the inner wall of the inclined pipe for spraying water into the inside of the inclined pipe to form a water film on the inner wall of the inclined pipe; a part of the water phase flowing out through the water phase outlet of the deoxidation device is recycled to the flushing water replenishment port of the washing device for providing flushing water to the washing device, and the other part is recycled to the fan-shaped nozzle and the flushing nozzle for providing flushing water to the high-temperature pipe.

[0013] In some specific embodiments, the circulation system further includes a booster and a heat exchanger; the water phase outlet of the deoxidation device is connected to the inlet of the booster, and the outlet of the booster is connected to the inlet of the heat exchanger, and the water phase after heat exchange in the heat exchanger is recycled to the flushing water replenishment port, the fan-shaped nozzle and the flushing nozzle.

[0014] In some preferred embodiments, a plurality of fan-shaped nozzles are arranged in the axial direction of the inclined pipe; preferably, the water spraying direction of the flushing nozzles arranged inside the circular arc bend pipe is along the tangent of the circular arc bend pipe.

[0015] In some specific embodiments, a pipe lining is provided on the inner wall of the vertical pipe to enhance the wear resistance and corrosion resistance of the pipe; since the washing device mentioned in the present invention is usually a tower tank type container, there must be a curved pipe part when the high-temperature gas enters the washing device from top to bottom, and the outlet of the cooling water spray port is on the same horizontal line as or lower than the lower edge of the pipe lining, so that after the cooling water spray is sprayed in an umbrella shape, while reducing the temperature of the high-temperature gas, it prevents the high-temperature gas and catalyst particles from scouring and friction erosion of the unlined part of the pipe.

[0016] In some specific embodiments, the inclined pipe is generally inclined downward with respect to the horizontal direction, and the angle with the horizontal direction is 0 to 90° (excluding 90°), i.e., less than 90°, for example, 20°, 30°, 50°, 80°; preferably 5 to 45°, for example, 15°, 30°, 40°.

[0017] The temperature of the high-temperature gas used for quenching and washing solids by the circulation system provided by the present invention is less than 350°C, preferably 200-320°C; the pressure of the high-temperature gas containing solid particles is less than 0.8MPa, preferably 0.05-0.2MPa; the particle content in the high-temperature gas containing solid particles is ≤186 mg / Nm 3 , the particle size of the particles in the high-temperature gas containing solid particles is less than 100 μm.

[0018] In the circulation system provided by the present invention, the chemical oxygen demand of the water phase in the water phase outlet of the deoxidation device is ≤1500 mg / L, preferably ≤1300 mg / L; the content of total insoluble matter in the water phase is ≤100 mg / L, preferably ≤90 mg / L.

[0019] In the circulation system provided by the present invention, the circulation system also includes a control device, which includes a differential pressure gauge and a flow regulating valve; the differential pressure gauge is used to monitor the pressure difference in the inclined pipeline, wherein the pressure difference of the high-temperature gas in the inclined pipeline is between 0 and 200 kPa, for example, 50 kPa, 100 kPa, 150 kPa; the flow regulating valve is used to adjust the spray water volume of the fan-shaped nozzle and the flushing nozzle. In some specific embodiments, the water spray flow rate of the fan-shaped nozzle and the flushing nozzle is between 1.0 and 8.0 t / h, for example, 2.0 t / h, 4.0 t / h, 6.0 t / h.

[0020] The circulation system provided by the present invention can be used to process the reaction product gas of a methanol to hydrocarbons device or the reaction product gas of a catalytic cracking device; as is well known to those skilled in the art, the reaction product gas of the above-mentioned methanol to hydrocarbons device or the reaction product gas of a catalytic cracking device contains, in addition to high-temperature gas, solid particles and self-produced water in the product gas. The circulation system of the present invention utilizes the characteristic that the self-produced water in the product gas is circulated in the system, and pressurizes it and sends it to the high-temperature pipeline to flush and cool the pipeline through various nozzles.

[0021] The above technical solution has the following technical effects:

[0022] The present invention utilizes the characteristic that the self-produced water in the reaction product gas of a methanol to hydrocarbon device or the reaction product gas of a catalytic cracking device can be recycled, redesigns the product gas pipeline and its accessory layout, pressurizes the self-produced water in the circulation system, divides it into two parts, cooling and flushing, and respectively sends them to the high-temperature pipeline through nozzles to flush and cool the pipeline, so as to achieve the purpose of protecting the high-temperature pipeline and cleaning solid sediments. It is particularly suitable for solving the long-term agglomeration problem of solid catalysts in horizontal or angled transmission pipelines; at the same time, the flushing water can be used in the subsequent circulation system, and no new medium will be introduced into the subsequent system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 : An embodiment of the circulation system provided by the present invention;

[0024] Figure 2 : Figure 1 A partial enlarged view of the arc bend in the circulation system provided;

[0025] Figure 3 : Figure 1 A partial schematic diagram of the inclined pipe in the circulation system is provided;

[0026] Among them, 1. high-temperature pipeline, 2. washing device, 3. solid-liquid separation device, 4. deoxidation device, 5. booster device, 6. heat exchanger, 7. arc elbow, 8. cooling water nozzle, 9. vertical pipeline, 10. inclined pipeline, 11. reaction product gas inlet, 12. reaction product gas outlet, 13. product gas outlet, 14. flushing water replenishment port, 15. washing water outlet, 16. slurry discharge port, 17. inlet, 18. water phase outlet, 19. gas phase outlet, 20. pipeline lining, 21. flushing nozzle, 22. fan-shaped nozzle. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the present invention, the present invention will be further described below in conjunction with examples. It should be understood that the following examples are only for a better understanding of the present invention and do not mean that the present invention is limited to the following examples.

[0028] Unless defined otherwise, 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 belongs.

[0029] The present invention provides a circulation system for protecting high-temperature pipelines by quenching and washing solids, which is used to wash solid particles (such as catalyst fine powder, etc.) entrained in the reaction product gas away from the reaction gas to avoid agglomeration on the inner wall of the high-temperature pipeline, which will lead to a decrease in the flux of the product gas pipeline, the weight of the deposited catalyst exceeding the bearing capacity of the pipeline, damage to the equipment, and serious blockage. The circulation system of the present invention mainly includes: a high-temperature pipeline 1, a washing device 2, a solid-liquid separation device 3, and a deoxidation device 4;

[0030] Among them, Figure 1 As shown, the high-temperature pipeline 1 includes a vertical pipeline 9 and an inclined pipeline 10 connected to the vertical pipeline 9. The connection between the vertical pipeline 9 and the inclined pipeline 10 is connected by an arc elbow 7. A reaction product gas inlet 11 is provided at the top of the vertical pipeline 9, and a reaction product gas outlet 12 is provided at the bottom of the inclined pipeline 10, which is used to transport the reaction product gas to the system of the present invention for circulation treatment. In some specific embodiments, the angle between the inclined pipeline 10 and the horizontal direction is 0 to 90°, preferably 5 to 45°. A cooling water spray port 8 is provided above the arc elbow 7 at the intersection of the inclined pipeline 10 and the vertical pipeline 9, which is used to spray water into the interior of the high-temperature pipeline 1 to reduce the temperature of the high-temperature gas just after entering the vertical pipeline 9 to protect the inner wall of the high-temperature pipeline 1.

[0031] A flushing nozzle 21 is provided at the arc bend 7 at the intersection of the inclined pipe 10 and the vertical pipe 9 to spray water into the arc bend 7; in some preferred embodiments, the water spraying direction of the flushing nozzle 21 in the arc bend 7 is along the tangent direction of the arc bend 7, which is used to remove solid sediments or mud accumulated at the bend of the pipe due to gravity in the high-temperature gas containing solid particles, so as to avoid blockage in the pipe. At the same time, a fan-shaped nozzle 22 is provided on the inner wall of the inclined pipe 10. As is well known to those skilled in the art, the spray channel of the fan-shaped nozzle 22 is large and smooth, and the shape of the spray is a fan-shaped at various angles. The fan-shaped cross-section of the spray produces a gradually tapering edge, the spray particles are fine, and the water flow is evenly distributed; in some specific embodiments, such as Figure 3As shown, a plurality of fan-shaped nozzles 22 are arranged along the axial direction of the inclined pipe 10. After entering the pipe, the water flow sprayed by the fan-shaped nozzle 22 is pushed along the fan-shaped direction of the pipe wall, contacts the water flow surface of the next fan-shaped nozzle 22, and fully washes the solid particles in the reaction product gas. In order to form a water film on the inner wall of the inclined pipe 10 that completely covers 360° in the pipe to protect the pipe, a corresponding number of fan-shaped nozzles 22 can be correspondingly equipped. In some specific embodiments, the angle of the fan-shaped water mist sprayed by the fan-shaped nozzle 22 is less than 180°, preferably 60° to 120°.

[0032] In the circulation system provided by the present invention, the high-temperature gas passes through the vertical pipe 9 from top to bottom and then enters the inclined pipe 10 after passing through the arc bend 7. A pipe lining 20 is arranged on the inner wall of the vertical pipe 9 to enhance the wear resistance and corrosion resistance of the pipe. In some specific embodiments, as shown in FIG. 2 , the water outlet of the cooling water nozzle 8 is at the same horizontal line as or lower than the lower edge of the pipe lining 20 to prevent the high-temperature gas and catalyst particles from scouring and frictionally corroding the part of the pipe without the pipe lining 20.

[0033] The reaction product gas enters the washing device 2 through the product gas inlet on the washing device 2 after being cooled and flushed in the high-temperature pipeline 1, and enters the device through the flushing water replenishment port 14 for water washing. The washed product gas is discharged from the product gas outlet 13 and enters the downstream process for further processing; in some specific embodiments, the above-mentioned washing device 2 can be selected from a water washing tower, a quenching tower, a cooling tower, etc.

[0034] The washing water after washing by the washing device 2 flows to the liquid inlet 17 of the solid-liquid separation device 3 through the washing water outlet 15. After entering the solid-liquid separation device 3, the washing water containing solid particles is subjected to liquid-solid separation in the solid-liquid separation device 3, and the separated slurry containing solid particles is discharged from the slurry outlet 16, and the separated liquid phase is discharged from the liquid phase outlet 19; in some specific embodiments, the above-mentioned solid-liquid separation device 3 can be a cyclone separator, which separates the liquid phase and the solid phase by centrifugation, or an online backwash filter can be selected to filter out the solid phase by setting the filter with an online backwash program.

[0035] The liquid phase water separated by the solid-liquid separation device 3 enters the deoxidation device 4 through the inlet 17. The deoxidation device 4 can be a purification tower, a stripping tower, etc.

[0036] In the circulation system of the present invention, a part of the water phase flowing out through the water phase outlet 18 of the deoxidation device 4 is recycled to the flushing water replenishment port 14 of the washing device 2 for providing flushing water to the washing device 2, and the other part is recycled to the fan-shaped nozzle 22 and the flushing nozzle 21 for providing flushing water to the high-temperature pipeline 1.

[0037] In some specific embodiments, the circulation system also includes a booster 5 and a heat exchanger 6. The water phase removed by the deoxidation device 4 enters the booster 5 for boosting, and then enters the heat exchanger 6 from the inlet of the heat exchanger 6 for heat exchange. A part of the flushing water after heat exchange is recycled to the flushing water replenishment port 14 of the washing device 2, and the other part is recycled to the fan-shaped nozzle 22 and the flushing nozzle 21 to provide flushing water to the high-temperature pipeline 1.

[0038] In some preferred embodiments, the circulation system further includes a control device, which includes a differential pressure gauge and a flow control valve; the differential pressure gauge is arranged at both ends of the inclined pipeline 10, and is used to monitor the pressure difference of the reaction product gas entering the inclined pipeline 10; the flow control valve is used to adjust the amount of spray water sprayed by the fan-shaped nozzle 22 and the flushing nozzle 21. For example, when the pressure difference of the reaction product gas entering the inclined pipeline 10 is between 0 and 200 kPa, the spray flow rate of the fan-shaped nozzle 22 and the flushing nozzle 21 is set by the flow control valve to change proportionally within 1.0 to 8.0 t / h, that is, the greater the pressure difference, the greater the nozzle flow rate, and the minimum flow rate of each nozzle is not less than 1.0 t / h, so as to prevent the catalyst from agglomerating in the high-temperature pipeline 1 during the process.

[0039] The circulation system provided by the present invention can be used to process the reaction product gas of a methanol to hydrocarbons device or the reaction product gas of a catalytic cracking device.

[0040] Now, let's take a methanol-to-olefins unit with an annual processing capacity of 1.8 million tons of methanol and an operating load of 80-110% as an example: using a continuous reaction-regeneration method, the reaction pressure is 0.8 MPa, methanol is used as the production raw material, the feed rate at 100% load is 229.125 t / h, and low-carbon olefins are generated in the reactor through catalytic action. The unit consumption of methanol is 3.0 t methanol / t olefin, the unit consumption of catalyst is 0.8 kg / t olefin, and the catalyst stacking density is 0.65-0.9 kg / m 3 The product gas carrying catalyst particles is separated from the reactor by a multi-stage cyclone separator, and the high-temperature potential energy is recovered in the heat exchanger 6. At this time, the product gas pressure is 0.62-0.75MPa, the temperature is 240-300℃, and the flow rate is 260600Nm 3 / h, the catalyst particle content in the product gas is 80~108mg / Nm 3 The reaction product gas enters the circulation system provided by the present invention as a high-temperature gas, and the reaction product gas enters the washing device 2 (for example, a water washing tower) through the high-temperature pipeline 1, and the treatment medium is water.

[0041] After passing through the washing device 2, the water in the product gas is combined with the cooled washing water to form washing water containing solids and enters the solid-liquid separation device 3 for solid-liquid separation. After separation, the slurry with a particulate matter content of >6000 mg / L is discharged to the sewage treatment plant for treatment, and the cleaner liquid water with a particulate matter content of <80 mg / L enters the oxide removal system 4 to remove by-products, and the oxide-containing water enters the subsequent process through the gas phase outlet 19. The output 280 t / h fresh flushing water phase with a pressure of 1.2 MPa is pressurized by the flushing water pump and then cooled to 34°C by the heat exchanger 6. According to the working conditions, part of the water can be reused into the fan nozzle 22 and the flushing nozzle 21 to protect the high-temperature pipeline 1; the other part of the fresh flushing water enters the washing device 2 from the flushing water replenishment port 14 to play a self-circulating role or be sent out for treatment.

[0042] During the start-up process, when the circulating system of the present invention is used to treat the methanol to olefins unit, before the nitrogen purge is completed and the temperature is started, deoxygenated water should be added into the washing device 2 through the flushing water replenishment port 14 to establish the circulation of the system; at the same time, the fan-shaped nozzle 22 and the flushing nozzle 21 in the high-temperature pipeline 1 are put into use. Since the catalyst content is low during the purge and heating process, each nozzle is controlled to a minimum flow rate of 1.0 t / h at this time.

[0043] During the heating process of the reactor, the medium in the high temperature pipe 1 is nitrogen, the temperature is less than 330°C, and the nitrogen volume is less than 120000Nm 3 / h, at which time the catalyst particle content in the medium is less than 20mg / Nm 3 As the reactor temperature gradually rises to 200°C, the cooling water nozzle 8 is put into use to protect the high-temperature pipe 1. As the reactor temperature rises to 380°C, when the high-temperature fluidized catalyst is added to the reactor, the catalyst is added and the load is lower than 80%, the catalyst is lost greatly. At this time, the catalyst particle content in the high-temperature pipe 1 is 150-180 mg / Nm 3 , adjust the flow rate of each nozzle in the fan-shaped nozzle 22 and the flushing nozzle 21 to the maximum value of 4.0 t / h, and form a water film layer of a certain thickness on the inner wall of the high-temperature pipeline 1 to prevent the catalyst lost during the start-up process from agglomerating on the pipe wall. The water film layer can also protect the high-temperature gas from affecting the high-temperature pipeline 1.

[0044] In the normal operation process, when the operating load is between 80% and 110%, the operating conditions are the same as the operating parameters of the basic process. At this time, the maximum flow rate of the product gas from the outlet of the multi-stage cyclone separator to the inlet of the quenching tower is 286660Nm at 110% load. 3 / h, the solid particle content in the reaction product gas is 119mg / Nm 3, after the heat recovery of the reaction product gas from the multi-stage cyclone separator, the temperature is lower than 230°C, and the normal water flow rate of the outlet of the fan-shaped nozzle 22 and the flushing nozzle 21 is 2.4t / h. At this time, by measuring the pressure difference at both ends of the high-temperature pipeline 1, the pressure difference is set within 0-160kPa, and the flow rate of the fan-shaped nozzle 22 and the flushing nozzle 21 is set to change proportionally within 1.0-4.0t / h through the regulating valve, that is, the greater the pressure difference, the greater the nozzle flow rate, and the minimum flow rate of each nozzle is not less than 1.0t / h, so as to prevent the catalyst from agglomerating in the high-temperature pipeline 1 during the process.

[0045] During the shutdown process, similar to the startup process, when the operating load gradually drops below 80% and the catalyst is unloaded, the flow rate of the reaction product gas is less than 208480Nm 3 / h, at this time, the catalyst particle content in the high-temperature pipeline 1 is 150-180 mg / Nm 3 , there is a large loss of catalyst, the flow rate of each fan-shaped nozzle 22 and the flushing nozzle 21 is adjusted to the maximum value of 4.0t / h, the washing device 2 and the deoxidation device 4 continue to use the self-produced water, that is, the water phase treated by the deoxidation device 4 to maintain the circulation of the system.

[0046] When the reactor stops feeding, the catalyst particles remaining in the reaction-regeneration system that have not been discharged will enter the washing device 2 through the high-temperature pipeline 1 along with the replacement and purge nitrogen during the process of using nitrogen to replace and purge the reactor. In this process, the purge nitrogen flow rate does not exceed 100,000 Nm 3 / h. At this flow rate, the linear velocity of the purge gas in the high-temperature pipeline 1 is lower than 23 m / s during normal operation. The content of solid particles in the reaction product gas increases. The nozzle flow rates of the fan nozzle 22 and the flushing nozzle 21 are still adjusted to the maximum value of 4.0 t / h to maintain the formation of a water film layer on the inner wall of the high-temperature pipeline 1 and continuously prevent the catalyst from agglomerating in the high-temperature pipeline 1.

Claims

1. A circulation system for protecting high-temperature pipelines by quenching and solidification, characterized in that: The circulatory system comprises: A high-temperature pipeline is used to transport the high-temperature gas containing solid particles to the washing device for washing; the high-temperature pipeline includes a vertical pipeline and an inclined pipeline connected to the vertical pipeline, the vertical pipeline and the inclined pipeline are connected through an arc elbow, a reaction product gas inlet is provided at the top of the vertical pipeline, a reaction product gas outlet is provided at the bottom of the inclined pipeline, and a cooling water spray port is provided at the upper part of the arc elbow for spraying water into the high-temperature pipeline to reduce the temperature; A washing device for washing the high-temperature gas containing solid particles; the washing device is provided with a product gas inlet, a product gas outlet, a washing water outlet and a flushing water replenishment inlet which are connected to the reaction product gas outlet through a pipeline; A solid-liquid separation device, wherein the solid-liquid separation device is provided with a liquid inlet, a slurry discharge outlet and a liquid phase outlet which are connected to the washing water outlet; A deoxidation device, used for removing oxides from the liquid phase separated by the solid-liquid separation device; the deoxidation device is provided with an inlet connected to the liquid phase outlet, a water phase outlet and a gas phase outlet containing oxides; Wherein, a flushing nozzle for spraying water into the inside of the circular arc bend is provided at the circular arc bend, and a fan-shaped nozzle is provided on the inner wall of the inclined pipe for spraying water into the inside of the inclined pipe to form a water film on the inner wall of the inclined pipe; a part of the water phase flowing out through the water phase outlet of the deoxidation device is recycled to the flushing water replenishment port of the washing device for providing flushing water to the washing device, and the other part is recycled to the fan-shaped nozzle and the flushing nozzle for providing flushing water to the high-temperature pipe; The circulation system also includes a pressure booster and a heat exchanger; The water phase outlet of the deoxidation device is connected to the inlet of the booster device, and the outlet of the booster device is connected to the inlet of the heat exchanger. The water phase after heat exchange in the heat exchanger is recycled to the flushing water replenishment port, the fan-shaped nozzle and the flushing nozzle; A plurality of fan-shaped nozzles are arranged in the axial direction of the inclined pipe; A pipeline lining is provided on the inner wall of the vertical pipeline to enhance the wear resistance and corrosion resistance of the pipeline; The water outlet of the cooling water spray nozzle is at the same horizontal line as the lower edge of the pipe lining or is lower than the lower edge of the pipe lining.

2. The circulation system according to claim 1, characterized in that: The water spraying direction of the flushing nozzle arranged inside the circular arc bend pipe is along the tangent of the circular arc bend pipe.

3. The circulation system according to claim 1, characterized in that: The inclined pipe is inclined downward, and the angle between the inclined pipe and the horizontal direction is 0 to 90 degrees.

4. The circulation system according to claim 3, characterized in that: The inclined pipe is inclined downward, and the angle between the inclined pipe and the horizontal direction is 5 to 45 degrees.

5. The circulation system according to any one of claims 1 to 4, characterized in that: The temperature of the high-temperature gas containing solid particles is less than 350° C. The pressure of the high temperature gas containing solid particles is less than 0.8 MPa; The particle content in the high temperature gas containing solid particles is ≤186mg / Nm 3 , the particle size of the particles in the high-temperature gas containing solid particles is less than 100 μm.

6. The circulation system according to claim 5, characterized in that: The temperature of the high-temperature gas containing solid particles is 200-320°C.

7. The circulation system according to claim 5, characterized in that: The pressure of the high temperature gas containing solid particles is 0.05-0.2 MPa.

8. The circulation system according to any one of claims 1 to 4, 6 and 7, characterized in that: The chemical oxygen demand of the water phase in the water phase outlet of the deoxidation device is ≤1500 mg / L; The content of total insoluble matter in the aqueous phase is ≤100 mg / L.

9. The circulation system according to claim 8, characterized in that: The chemical oxygen demand of the water phase in the water phase outlet of the deoxidation device is ≤1300 mg / L.

10. The circulation system according to claim 8, characterized in that The content of total insoluble matter in the aqueous phase is ≤90 mg / L.

11. The circulation system according to any one of claims 1 to 4, 6, 7, 9 and 10, characterized in that: The circulation system further comprises a control device, which comprises a differential pressure gauge and a flow regulating valve; The differential pressure gauge is used to monitor the pressure difference in the inclined pipeline; The flow regulating valve is used to adjust the spray water volume of the fan-shaped nozzle and the flushing nozzle.

12. The circulation system according to claim 11, characterized in that The pressure difference of the high-temperature gas in the inclined pipeline is 0 to 200 kPa, and the water spray flow rates of the fan-shaped nozzle and the flushing nozzle are 1.0 to 8.0 t / h.

13. The circulation system according to any one of claims 1 to 4, 6, 7, 9, 10, and 12, characterized in that: The circulation system can be used to process the reaction product gas of a methanol to hydrocarbons device or the reaction product gas of a catalytic cracking device.

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