Indirect hot feeding methanol-to-olefin device

Abstract

The invention relates to the technical field of methanol-to-olefin, in particular to an indirect hot feeding methanol-to-olefin device which comprises a methanol tank area, and the inlet end of the methanol tank area is connected with a methanol synthesis device. According to the indirect hot feeding methanol-to-olefin device, through the collaborative design of cyclone separation and self-cleaning filtration, the problem of wax blockage is thoroughly solved, and the flow speed of a propeller impeller in a pipeline is increased, so that the cyclone efficiently separates 90% or more of crude wax; residual micronized wax is intercepted by the polytetrafluoroethylene static pressure filter screen in the spherical buffer filter kettle, and the unique structure converts high-speed fluid dynamic pressure into static pressure, so that the filter screen is prevented from being impacted and damaged; meanwhile, fluid kinetic energy drives an impeller linkage brush plate to scrape a wax layer on the surface of the filter screen in real time and discharge the wax layer into a precipitation cabin, so that zero-energy-consumption self-cleaning is realized. According to the technology, shutdown cleaning caused by blockage of a traditional filter screen is reduced, the maintenance cost is reduced by 80%, and it is guaranteed that the device continuously operates for more than 8000 hours.

Description

Technical Field

[0001] The present invention relates to the technical field of methanol to olefins, in particular to a methanol to olefins device with indirect heat feed. Background Art

[0002] To prevent wax from entering the MTO unit, a cold feed system is currently used. This means that the methanol is cooled to 40°C in the methanol unit before entering the tank. This allows the wax to be removed during the cooling process and within the methanol tank. This reduces the amount of wax in the methanol entering the MTO unit, thereby reducing the wax content in the MTO unit's quench water and other components. The current problem is that the cooler frequently clogs, requiring steam to melt the accumulated wax over time. Wax in the methanol tank area can cling to the tank walls. If not cleaned for a long time, this wax can fall off and potentially enter the MTO unit through the pump.

[0003] It is now necessary to design a device to remove wax during the cooling process, so that the methanol cooler will not be blocked, and the wax in the methanol tank will be reduced, avoiding the possibility of wax peeling off and re-entering the MTO. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a methanol to olefins device with indirect heat feed, which solves the above-mentioned problems.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a methanol-to-olefins device with indirect heat feed, comprising a methanol tank farm, wherein the inlet end of the methanol tank farm is connected to a methanol synthesis device, the methanol synthesis device including but not limited to a methanol heat exchanger and a hot methanol water cooler connected in sequence, the outlet end of the methanol tank farm is connected to the methanol-to-olefins device, and a wax cyclone separation mechanism is provided in the connecting pipe between the methanol heat exchanger and the hot methanol water cooler; The wax cyclone separation mechanism includes an acceleration pipe connected to the output pipe of the methanol heat exchanger, a cyclone connected to the acceleration pipe, and a buffer filter kettle connected to the overflow pipe on the top of the cyclone, and the buffer filter kettle is connected to the input end of the hot methanol water cooler; The inner cavity of the buffer filter kettle is fixedly connected to a static pressure filter screen through a cross reinforcement bracket. One side of the static pressure filter screen is rotatably connected to a rotating shaft facing the connection point between the overflow pipe of the acceleration pipe and the buffer filter kettle. The end of the rotating shaft is rotatably connected to an impeller. The surface of the rotating shaft is fixedly connected to a brush plate that abuts the surface of the static pressure filter screen. The bottom of the buffer filter kettle is connected to a sedimentation chamber located below the brush plate. The bottom of the sedimentation chamber is connected to a slag discharge pipe controlled by a solenoid valve. When in use, the raw materials accelerated by the acceleration pipe enter the cyclone, and most of the solid impurities The quality is output from the bottom, and the remaining liquid enters the buffer filter kettle from the overflow pipe. At this time, the static pressure filter can convert the dynamic pressure of the high-speed liquid into static pressure, and then smoothly output the methanol from the other side. When the methanol enters at high speed, it impacts the impeller on the rotating shaft, driving the impeller to rotate. When the impeller rotates, it drives the rotating shaft to rotate. The solid wax precipitated on the surface of the static pressure filter is cleaned by the brush plate and scraped into the sedimentation chamber below. It is discharged by regularly opening the slag discharge pipe, which can effectively perform self-cleaning. The rotating shaft is rotatably connected to the bracket fixed in the buffer filter kettle.

[0006] As a further solution of the present invention: the buffer filter kettle is a spherical chamber, and the output pipe connected to the hot methanol water cooler has a larger diameter than the acceleration pipe.

[0007] As a further solution of the present invention: the acceleration pipe has two sections and forms a right angle, and an acceleration mechanism is provided in each of the two right-angle sections. The diameter of the acceleration pipe is smaller than the diameter of the discharge pipe of the methanol heat exchanger.

[0008] As a further embodiment of the present invention, the acceleration mechanism includes a drive motor fixed to the side of the acceleration pipe and a power shaft driven to rotate by the drive motor within the acceleration pipe. The power shaft is located within the acceleration pipe and is fixedly connected to a rotating paddle. Both rotating paddles are in the shape of propeller-type impellers, which can form a strong axial liquid flow in the pipe. At the same output pressure, the smaller the pipe diameter, the faster the flow rate, further increasing the flow rate of the crude oil in the acceleration pipe. Therefore, the crude oil passing through the acceleration section can enter the cyclone at a higher flow rate.

[0009] As a further solution of the present invention: the static pressure filter is made of polytetrafluoroethylene.

[0010] As a further solution of the present invention: the methanol tank area includes but is not limited to MTO-grade methanol tanks and methanol delivery pumps connected in sequence, the methanol synthesis unit includes but is not limited to a methanol heat exchanger and a hot methanol water cooler connected in sequence, and the methanol to olefins unit includes but is not limited to a methanol buffer tank, a methanol feed pump, a heat extractor in the reactor, a steam-condensate heat exchanger, a three-way device, a methanol reaction gas heat exchanger and an MTO reactor connected in sequence, and the three-way device includes a stripping gas heat exchanger, a steam heat exchanger and a methanol booster pump.

[0011] Compared with the prior art, the present invention has the following beneficial effects: The collaborative design of cyclone separation and self-cleaning filtration completely solves the problem of wax clogging. The propeller impeller in the pipeline accelerates the flow rate, enabling the cyclone to efficiently separate over 90% of the crude wax. Residual microwax is intercepted by the polytetrafluoroethylene static pressure filter in the spherical buffer filter. Its unique structure converts high-speed fluid dynamic pressure into static pressure, preventing impact damage to the filter. Simultaneously, the fluid kinetic energy drives the impeller-linked brush plate, which scrapes the wax layer off the filter surface in real time and discharges it into the sedimentation chamber, achieving zero-energy self-cleaning. This technology reduces the downtime for cleaning caused by traditional filter clogging, reducing maintenance costs by 80% and ensuring continuous operation of the device for over 8,000 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 Schematic diagram of the structure of the cyclone assembly of the present invention; Figure 3 It is a structural cross-sectional view of the filter kettle of the present invention.

[0013] In the figure: 1. Methanol heat exchanger; 2. Hot methanol water cooler; 3. MTO-grade methanol tank; 4. Methanol delivery pump; 5. Methanol buffer tank; 6. Methanol feed pump; 7. Reactor heat extractor; 8. Steam-condensate heat exchanger; 9. Stripping gas heat exchanger; 10. Steam heat exchanger; 11. Methanol booster pump; 12. Methanol reaction gas heat exchanger; 13. MTO reactor; 18. Acceleration pipe; 19. Cyclone; 20. Buffer filter kettle; 21. Power shaft; 22. Rotating paddle; 23. Static pressure filter; 24. Rotating shaft; 25. Brush plate; 26. Bracket; 27. Impeller; 28. Sedimentation chamber; 29. Slag discharge pipe. DETAILED DESCRIPTION

[0014] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0015] See also Figure 1-Figure 3 The present invention provides a technical solution: a methanol-to-olefins device with indirect heat feed, comprising a methanol tank farm, wherein the inlet end of the methanol tank farm is connected to a methanol synthesis device, the methanol synthesis device including but not limited to a methanol heat exchanger 1 and a hot methanol water cooler 2 connected in sequence, the outlet end of the methanol tank farm is connected to the methanol-to-olefins device, and a wax cyclone separation mechanism is provided in the connecting pipe between the methanol heat exchanger 1 and the hot methanol water cooler 2; The wax cyclone separation mechanism includes an acceleration pipe 18 connected to the output pipe of the methanol heat exchanger 1, a cyclone 19 connected to the acceleration pipe 18, and a buffer filter kettle 20 connected to the overflow pipe at the top of the cyclone 19. The buffer filter kettle 20 is connected to the input end of the hot methanol water cooler 2; The inner cavity of the buffer filter kettle 20 is fixedly connected with a static pressure filter screen 23 through a cross reinforcement bracket. One side of the static pressure filter screen 23 is rotatably connected to a rotating shaft 24 facing the connection point between the overflow pipe of the acceleration pipe 18 and the buffer filter kettle 20. The end of the rotating shaft 24 is rotatably connected to an impeller 27. The surface of the rotating shaft 24 is fixedly connected with a brush plate 25 abutting the surface of the static pressure filter screen 23. The bottom of the buffer filter kettle 20 is connected to a sedimentation chamber 28 located below the brush plate 25. The bottom of the sedimentation chamber 28 is connected to a slag discharge pipe 29 controlled by a solenoid valve. When in use, the raw materials accelerated by the acceleration pipe 18 enter the cyclone 19, and most of the solid impurities The quality is output from the bottom, and the remaining liquid enters the buffer filter kettle 20 from the overflow pipe. At this time, the static pressure filter 23 can convert the dynamic pressure of the high-speed liquid into static pressure, and then smoothly output the methanol from the other side. When the methanol enters at high speed, it impacts the impeller 27 on the rotating shaft 24, driving the impeller 27 to rotate. When the impeller 27 rotates, it drives the rotating shaft 24 to rotate. The solid wax precipitated on the surface of the static pressure filter 23 is cleaned by the brush plate 25 and scraped into the sedimentation chamber 28 below. It is discharged by regularly opening the slag discharge pipe 29, which can effectively perform self-cleaning. The rotating shaft 24 is rotatably connected to the bracket 26 fixed in the buffer filter kettle 20.

[0016] The buffer filter kettle 20 is a spherical chamber, and the diameter of the output pipe connected to the hot methanol water cooler 2 is larger than that of the acceleration pipe 18.

[0017] The accelerating pipe 18 has two sections and is at right angles to each other. Accelerating mechanisms are provided in both sections. The diameter of the accelerating pipe 18 is smaller than the diameter of the discharge pipe of the methanol heat exchanger 1 .

[0018] The acceleration mechanism includes a drive motor fixed to the side of the acceleration pipe 18 and a power shaft 21 driven to rotate by the drive motor in the inner cavity of the acceleration pipe 18. The power shaft 21 is located in the inner cavity of the acceleration pipe 18 and is fixedly connected to a rotating paddle 22. Both rotating paddles 22 are in the shape of propeller-type impellers, which can form a strong axial liquid flow in the pipe. Under the same output pressure, the smaller the pipe diameter, the faster the flow rate, further increasing the flow rate of the crude oil in the acceleration pipe 18. Therefore, the crude oil passing through the acceleration part can enter the cyclone 19 at a higher flow rate.

[0019] The static pressure filter 23 is made of polytetrafluoroethylene.

[0020] The methanol tank area includes but is not limited to an MTO-grade methanol tank 3 and a methanol delivery pump 4 connected in sequence; the methanol synthesis unit includes but is not limited to a methanol heat exchanger 1 and a hot methanol water cooler 2 connected in sequence; the methanol to olefins unit includes but is not limited to a methanol buffer tank 5, a methanol feed pump 6, a heat extractor in the reactor 7, a steam-condensate heat exchanger 8, a three-way device, a methanol reaction gas heat exchanger 12 and an MTO reactor 13 connected in sequence; the three-way device includes a stripping gas heat exchanger 9, a steam heat exchanger 10 and a methanol booster pump 11.

[0021] The outlet end of the hot methanol water cooler 2 is connected to the inlet end of the MTO-grade methanol tank 3, the outlet end of the methanol delivery pump 4 is connected to the inlet end of the methanol buffer tank 5, and the outlet end of the methanol feed pump 6 is connected to the inlet end of the methanol heat exchanger 1 through the first loop to transport the unheated methanol extracted from the methanol buffer tank 5. The outlet end of the methanol heat exchanger 1 is connected to the inlet end of the heat extractor 7 in the reactor through the second loop to transport the preheated methanol extracted from the methanol heat exchanger 1. The three-way device includes a stripping gas heat exchanger 9, a steam heat exchanger 10 and a methanol booster pump 11. The steam condensate heat exchanger 8 is connected to the inlet ends of the stripping gas heat exchanger 9, the steam heat exchanger 10 and the methanol booster pump 11 at the same time through three branches. The outlet ends of the stripping gas heat exchanger 9, the steam heat exchanger 10 and the methanol booster pump 11 are sequentially merged into the methanol reaction gas heat exchanger 12. The outlet end of the methanol booster pump 11 is also connected to an atomizing nozzle.

[0022] When the present invention is used After being accelerated through the acceleration pipeline, the waxy methanol enters the cyclone 19 tangentially, where the centrifugal force causes the heavy wax residue to sink and be discharged. The overflow liquid impacts the impeller 27 in the buffer filter kettle 20, driving the brush plate 25 to rotate and scrape the static pressure filter 23. The intercepted micro-wax is continuously cleaned into the sedimentation chamber 28. The filtered methanol is output to the water cooler at a stable pressure through the expansion chamber. The entire process requires no external intervention.

[0023] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A methanol-to-olefins device with indirect heat feed, comprising a methanol tank farm, wherein the inlet end of the methanol tank farm is connected to a methanol synthesis device, wherein the methanol synthesis device includes but is not limited to a methanol heat exchanger (1) and a hot methanol water cooler (2) connected in sequence, and the outlet end of the methanol tank farm is connected to a methanol-to-olefins device, characterized in that: A wax cyclone separation mechanism is provided at the connecting pipe between the methanol heat exchanger (1) and the hot methanol water cooler (2); The wax cyclone separation mechanism comprises an acceleration pipe (18) connected to the output pipe of the methanol heat exchanger (1), a cyclone (19) connected to the acceleration pipe (18), and a buffer filter kettle (20) connected to the overflow pipe at the top of the cyclone (19), wherein the buffer filter kettle (20) is connected to the input end of the hot methanol water cooler (2); The inner cavity of the buffer filter kettle (20) is fixedly connected to a static pressure filter screen (23) via a cross reinforcement bracket. One side of the static pressure filter screen (23) is rotatably connected to a rotating shaft (24) facing the connection point between the overflow pipe of the acceleration pipe (18) and the buffer filter kettle (20). The end of the rotating shaft (24) is rotatably connected to an impeller (27). The surface of the rotating shaft (24) is fixedly connected to a brush plate (25) that abuts the surface of the static pressure filter screen (23). The bottom of the buffer filter kettle (20) is connected to a sedimentation chamber (28) located below the brush plate (25). The bottom of the sedimentation chamber (28) is connected to a slag discharge pipe (29) controlled by a solenoid valve.

2. The indirect heat feed methanol to olefins device according to claim 1, characterized in that: The buffer filter kettle (20) is a spherical chamber, and the output pipe connected to the hot methanol water cooler (2) has a larger diameter than the acceleration pipe (18).

3. The methanol to olefins plant with indirect heat feed according to claim 1, characterized in that: The acceleration pipe (18) has two sections that are at right angles, and an acceleration mechanism is provided in each of the two right-angled sections. The diameter of the acceleration pipe (18) is smaller than the diameter of the discharge pipe of the methanol heat exchanger (1).

4. The methanol to olefins device with indirect heat feed according to claim 3, characterized in that: The acceleration mechanism includes a driving motor fixed to the side of the acceleration pipe (18) and a power shaft (21) driven to rotate by the driving motor in the inner cavity of the acceleration pipe (18). The power shaft (21) is located in the inner cavity of the acceleration pipe (18) and is fixedly connected to a rotating paddle (22).

5. The methanol to olefins plant with indirect heat feed according to claim 1, characterized in that: The static pressure filter (23) is made of polytetrafluoroethylene.

6. The methanol to olefins plant with indirect heat feed according to claim 1, characterized in that: The methanol tank area includes but is not limited to sequentially connected MTO-grade methanol tanks (3) and methanol transfer pumps (4); the methanol-to-olefins unit includes but is not limited to sequentially connected methanol buffer tanks (5), methanol feed pumps (6), reactor heat extractors (7), steam-condensate heat exchangers (8), three-way devices, methanol reaction gas heat exchangers (12) and MTO reactors (13); the three-way devices include stripping gas heat exchangers (9), steam heat exchangers (10) and methanol booster pumps (11).

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