A built-in multi-tube supersonic coagulation-cyclone-coalescence filter

Abstract

The application discloses a built-in multi-pipe supersonic condensation-cyclone-coalescence filter, which comprises a shell, a cyclone pre-separation module, a supersonic nozzle steam condensation module, a multi-stage guide vane type mist cyclone separation module and a coalescence filter core filter module are sequentially arranged in the shell from bottom to top. The filter can not only separate free liquid droplets carried in natural gas, but also deeply remove lubricating oil steam, hydrocarbons and water vapor contained in the natural gas through phase change condensation. The filter has the characteristics of large operation flexibility and high separation efficiency.

Description

Technical Field

[0001] This invention relates to a gas-liquid two-phase flow separation and natural gas purification device, and particularly to a special device for gas-liquid separation of natural gas. Background Technology

[0002] In the natural gas extraction and gathering process, free droplets and vaporized water, lubricating oil, or other hydrocarbons are frequently generated. As the transportation distance increases, these free droplets continuously deposit. Changes in temperature and pressure can also cause the vaporized water, lubricating oil, or other hydrocarbons to undergo phase changes, condensing into mist droplets and eventually agglomerating into larger droplets that settle. With increasing gas volume, the liquid phase deposited in the pipeline accumulates over time, easily leading to blockages, reducing the pipeline's cross-sectional area and effective transportation capacity, and causing corrosion damage. Therefore, natural gas should undergo effective gas-liquid separation before long-distance transportation to effectively remove free droplets and various vaporized components prone to phase change and condensation.

[0003] Currently, traditional gas-liquid separation equipment typically consists of multiple separation units. These units are highly sensitive to changes in the gas-liquid ratio and flow rate, are very heavy, and occupy a large area. Most common natural gas gas-liquid separation equipment is either a single-stage cyclone separator or a combination of cyclone and filtration. Single-stage cyclone gas-liquid separators are less effective at separating natural gas with high liquid content, while the combination of cyclone and filtration separators, although offering better separation performance, suffers from drawbacks such as high pressure drop and large footprint. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a built-in multi-tube supersonic condensation-cyclone-coalescing filter with high separation accuracy, strong adaptability and compact structure.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is implemented as follows:

[0006] The present invention provides a built-in multi-tube supersonic condensation-cyclone-coalescing filter, comprising a housing, wherein a cyclone pre-separation module, a supersonic nozzle steam condensation module, a multi-stage guide vane droplet cyclone separation module, and a coalescing filter module are arranged sequentially from bottom to top within the housing; a lower partition, an upper partition, a first support plate, a second support plate, a third support plate, and a fourth support plate are fixedly fixedly within the housing from bottom to top; the outer walls of the upper partition, lower partition, first support plate, second support plate, third support plate, and fourth support plate are shaped to match the inner wall of the housing and are fixedly connected along the circumferential direction.

[0007] The cyclone pre-separation module includes a drainage channel with one end connected to a lower drainage port at the bottom of the outer shell. The cavity inside the outer shell between the upper and lower partitions forms a liquid accumulation chamber. A liquid accumulation outlet is located on the outer shell corresponding to the lower part of the liquid accumulation chamber. A level gauge is installed on the outer shell at the location corresponding to the liquid accumulation chamber. Multiple vertically arranged cyclone tubes are installed inside the liquid accumulation chamber. Each cyclone tube includes a first cyclone tube cylinder fixed to the upper partition. The top inlet of the first cyclone tube cylinder communicates with a corresponding opening on the upper partition. The bottom outlet of a cyclone tube is located above the lower partition plate; a cyclone tube guide is installed in the upper part of the first cyclone tube body; the cavity inside the outer shell between the upper partition plate and the first support plate constitutes an air inlet chamber; the bottom of the vertically arranged lower riser pipe is fixed in the middle of the upper partition plate and communicates with the lower riser hole opened in the middle of the upper partition plate; the top of the lower riser pipe is fixed in the middle of the first support plate and communicates with the riser hole opened in the middle of the first support plate; an air inlet is opened on the outer shell corresponding to the lower part of the air inlet chamber; the separator inlet channel communicates with the air inlet.

[0008] The cavity inside the outer shell between the first support plate and the second support plate constitutes the nozzle inlet. The supersonic nozzle steam condensation module includes multiple nozzles arranged vertically. The second support plate has mounting holes that correspond one-to-one with the multiple nozzles. The mounting holes are fixed in the middle part of the nozzles. The multiple nozzles are Laval nozzles. A single supersonic nozzle segment consists of a tapering section, a throat, a diverging section, and a straight section from bottom to top.

[0009] The multi-stage guide vane type droplet cyclone separation module includes a rising air pipe that passes through a connection hole in the middle of the top of the third support plate. The rising air pipe is set vertically and fixed on the third support plate. The top wall of the small opening end of a truncated cone is fixedly connected to the bottom inlet wall of the rising air pipe. The top wall of the liquid collection chamber is fixedly connected to the bottom wall of the large opening end of the separation cone. The middle drain pipe passes through the outer shell and is connected to the liquid outlet inlet on the bottom wall of the liquid collection chamber. The liquid collection chamber is located above multiple nozzles.

[0010] Multiple guide vane cyclone tubes arranged vertically are evenly distributed along the outer circumference of the rising air pipe. Each guide vane cyclone tube includes a second cyclone tube body. A first-stage guide and a second-stage guide are respectively installed at the top inlet and the bottom outlet of the second cyclone tube body. The bottom of the second cyclone tube body is fixed to the separation cone and communicates with the separation cone. The outer wall of the second cyclone tube body is fixed to the outer wall of the rising air pipe by a support rod.

[0011] The cyclone tube guide, the first-stage guide, and the second-stage guide all include an intermediate column. Multiple guide blades are evenly connected along the circumferential direction on the side wall at the middle of the intermediate column. The upper part of the multiple guide blades is a vertical plate and the lower part is an arc-shaped plate.

[0012] The cavity within the outer casing between the third and fourth support plates forms a top drainage cavity. The coalescing filter module includes multiple coalescing filter elements whose lower parts are fixedly connected to mounting holes on the fourth support plate. The coalescing filter elements are arranged vertically. A top vent is opened on the outer casing at a position corresponding to the upper outlet of the coalescing filter element. The cavity within the outer casing between the fourth support plate and the end cap of the separator installed on the top of the outer casing is a venting cavity. An upper drainage port is opened on the outer casing corresponding to the lower part of the top drainage cavity, and a top vent is opened on the outer casing corresponding to the venting cavity.

[0013] Preferably, the boundary line equation of the tapering segment is:

[0014]

[0015] In the formula: r cr r1 is the throat radius; r1 is the inlet radius of the supersonic nozzle; and L is the length of the convergent section of the supersonic nozzle.

[0016] Preferably, multiple nozzles are evenly distributed along the same circumferential direction.

[0017] Preferably, the liquid collection cavity is hemispherical.

[0018] Preferably, the cyclone tube guide includes 6 guide vanes, each guide vane having an outlet angle of 42° with its arc plate. The first-stage guide and the second-stage guide each include 8 guide vanes, wherein the first-stage guide has an outlet angle of 42° with its arc plate and the second-stage guide has an outlet angle of 55° with its arc plate. The distance D between the bottom of the first-stage guide and the top of the second-stage guide is 1 / 2 of the total length L of the cyclone tube.

[0019] Preferably, the top and bottom of the intermediate column are bullet-shaped.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] (1) High separation accuracy and wide adaptability to natural gas processing capacity. Especially for inlet conditions with high liquid content, the pretreatment module can ensure that the final coalescing filter element is always in the best operating conditions, thus enabling the long-term operation of the entire equipment.

[0022] (2) Multiple functions such as cyclone separation, phase change condensation and coalescence filtration can be continuously realized in one device, and it has strong adaptability to the composition and distribution of liquid and gas phase components in the natural gas being processed.

[0023] (3) The structure is compact, with four modules arranged in a reasonable manner along the height direction inside a separator, which occupies a small area and is suitable for offshore oil and gas production platforms. Attached Figure Description

[0024] Figure 1 This is a cross-sectional view of the built-in multi-tube supersonic condensation-cyclone-coalescing filter provided by the present invention.

[0025] Figure 2 The diagram shows the structure of the DC guide vane cyclone tube for the pre-separation module provided by this invention.

[0026] Figure 3 The structural diagram of the pre-separation module DC guide vane cyclone guide provided by the present invention;

[0027] Figure 4 This is a structural diagram of the supersonic condensation module nozzle provided by the present invention;

[0028] Figure 5-1 is a structural diagram of the multi-stage guide vane type droplet cyclone separation module provided by the present invention;

[0029] Figure 5-2 for Figure 5-1 Sectional view AA of the structure shown;

[0030] Figure 6 The structure diagram of the DC guide vane cyclone separator for the multi-stage guide vane type droplet cyclone separation module provided by the present invention is shown below;

[0031] Figure 7 A schematic diagram of the first-stage guide vane type droplet cyclone separation module provided by the present invention;

[0032] Figure 8 This is a schematic diagram of the second-stage guide vane of the multi-stage guide vane type droplet cyclone separation module provided by the present invention. Detailed Implementation

[0033] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0034] like Figure 1As shown, the built-in multi-tube supersonic condensation-cyclone-coalescing filter proposed according to the present invention includes a shell. Inside the shell, from bottom to top, a cyclone pre-separation module, a supersonic nozzle steam condensation module, a multi-stage guide vane droplet cyclone separation module, and a coalescing filter module are arranged sequentially. Inside the shell, from bottom to top, a lower partition, an upper partition, a first support plate, a second support plate, a third support plate, and a fourth support plate are fixedly fixed. The outer walls of the upper partition, lower partition, first support plate, second support plate, third support plate, and fourth support plate are shaped to match the inner wall of the shell and are fixedly connected along the circumferential direction.

[0035] like Figure 1 , Figure 2 , Figure 3 As shown, the cyclone pre-separation module includes a drainage channel 5 connected at one end to a lower drainage port at the bottom of the outer shell. The cavity inside the outer shell between the upper and lower partitions forms a liquid accumulation chamber 4. A liquid accumulation outlet is opened on the outer shell corresponding to the lower part of the liquid accumulation chamber 4. A level gauge is installed on the outer shell corresponding to the liquid accumulation chamber 4. Multiple vertically arranged cyclone tubes are installed in the liquid accumulation chamber 4. Each cyclone tube includes a first cyclone tube cylinder 3-1 fixed to the upper partition. The top inlet of the first cyclone tube cylinder is connected to an opening corresponding to the upper partition. The bottom outlet of the first cyclone tube cylinder is located above the lower partition. A cyclone tube guide 3-2 is installed in the upper part of the first cyclone tube cylinder. The cavity inside the outer shell between the upper partition and the first support plate constitutes the air intake chamber 2. The bottom of the vertically arranged lower air pipe 6 is fixed in the middle of the upper partition and communicates with the lower air hole opened in the middle of the upper partition. The top of the lower air pipe 6 is fixed in the middle of the first support plate and communicates with the upper air hole opened in the middle of the first support plate. An air intake inlet is opened on the outer shell corresponding to the lower part of the air intake chamber. The separator inlet channel 1 communicates with the air intake inlet.

[0036] The natural gas to be processed enters the inlet chamber 2 through the separator inlet channel and is evenly distributed into each cyclone tube. Due to the deflection channel formed by the guide vanes of the cyclone tube guide 3-2, the straight-flowing airflow is turned into a strongly rotating airflow. Under the action of centrifugal force, the free liquid droplets contained in the natural gas are separated by gas-liquid cyclone separation. The separated droplets form a liquid film along the inner wall of the first cyclone tube cylinder 3-1 under the action of the downward airflow and gravity, and flow towards the outlet, finally being discharged into the liquid accumulation chamber 4. The liquid discharge operation is carried out according to the liquid level displayed by the liquid level gauge. The natural gas, which has been preliminarily purified by each cyclone tube, is collected in the lower riser pipe 6, flows upward from the cyclone pre-separation module, and enters the nozzle inlet 7 of the supersonic nozzle steam condensation module.

[0037] like Figure 1 , Figure 4As shown, the cavity inside the outer shell between the first support plate and the second support plate constitutes the nozzle inlet cavity 7. The supersonic nozzle steam condensation module includes multiple nozzles 8 arranged in a vertical direction. The second support plate has mounting holes that correspond one-to-one with the multiple nozzles 8. The mounting holes are fixed in the middle part of the nozzles 8. The multiple nozzles 8 are Laval nozzles. A single supersonic nozzle segment consists of a tapering section AB, a throat BC, a diverging section CD, and a straight section DE from bottom to top. Figure 4 Point O is the midpoint of the inlet end of the Laval nozzle, ox is the axis of symmetry of the Laval nozzle, and oy is the line segment passing through point O and perpendicular to ox.

[0038] The Laval nozzle increases airflow velocity by reducing the airflow cross-section, with the throat being the point of minimum diameter, where the airflow velocity reaches its highest. The section narrows from the inlet to the throat, and preferably, the boundary equation of this narrowing section is:

[0039]

[0040] In the formula: r cr R is the throat radius (mm); r1 is the inlet radius of the supersonic nozzle (mm); and L is the length of the convergent section of the supersonic nozzle (mm). The design curve of the convergent section is the most common characteristic line method.

[0041] The airflow entering the mouth of the nozzle is distributed into the nozzle. Due to the specially designed change in the nozzle flow channel cross-section, the airflow velocity is forced to increase sharply and the temperature to decrease until it is below the condensation point of the gas phase components. This condenses the lubricating oil vapor, water, and various hydrocarbon vapor components in the gas phase into droplets, which are then discharged with the airflow. The preferred multiple nozzles 8 are evenly distributed along the same circumferential direction, which can ensure uniform air intake in each nozzle and achieve optimal overall condensation and separation performance.

[0042] like Figure 1 As shown in Figure 5, the multi-stage guide vane type droplet cyclone separation module includes an ascending air pipe 13 that passes through a connection hole in the middle of the top of the third support plate 15. The ascending air pipe 13 is arranged vertically and fixed on the third support plate. The top wall of the small opening end of a separation cone 9 in the shape of a frustum is fixedly connected to the bottom inlet wall of the ascending air pipe 13. The top wall of the liquid collection chamber 11 is fixedly connected to the bottom wall of the large opening end of the separation cone 9. The liquid collection chamber 11 is preferably hemispherical, with a large volume, a large liquid capacity, and low flow resistance of the lower airflow. The middle drain pipe 12 passes through the outer shell and is connected to the liquid outlet inlet on the bottom wall of the liquid collection chamber 11. The liquid collection chamber 11 is located above multiple nozzles 8.

[0043] Multiple guide vane cyclone tubes 10, arranged vertically, are evenly distributed along the outer circumference of the rising air pipe 13. Each guide vane cyclone tube includes a second cyclone tube body 10-1. A first-stage guide 10-2 and a second-stage guide 10-3 are respectively installed at the top inlet and lower outlet of the second cyclone tube body. The bottom of the second cyclone tube body 10-1 is fixed to the separation cone 9 and communicates with the separation cone. The outer wall of the second cyclone tube body is fixed to the outer wall of the rising air pipe 13 by a support rod 14. In this way, multiple cyclone tubes, the separation cone, the liquid collection chamber, and the rising air pipe are connected into a whole and fixed to the third support plate 15 by the rising air pipe. The upward airflow discharged from the supersonic nozzle steam condensation module continues to flow upward until it reaches the third support plate 15, where it turns 180° and enters each cyclone tube 10. In the cyclone tube, the rotating airflow undergoes gas-liquid separation under the influence of gravity and enters the liquid collection chamber. After reaching a certain liquid volume, it is discharged from the separator through the intermediate drain pipe 12. After gas-liquid separation, the natural gas is discharged through the riser pipe 13 from the multi-stage guide vane type droplet cyclone separation module and enters the coalescing filter module.

[0044] The cyclone tube guide 3-2, the first-stage guide 10-2, and the second-stage guide 10-3 all include an intermediate column. Multiple guide blades are evenly connected circumferentially to the side wall at the center of the intermediate column. The upper part of each guide blade is a vertical plate, and the lower part is an arc-shaped plate. Preferably, the cyclone tube guide 3-2 includes 6 guide blades, and the exit angle of the arc-shaped plate of each guide blade (as shown in the figure, i.e., the angle between the tangent of the outer edge curve of the guide blade exit and the straight edge of the guide blade inlet) is 42°. Both the first-stage and second-stage guides include 8 guide blades, wherein the exit angle of the arc-shaped plate of the guide blades of the first-stage guide is 42°, and the exit angle of the arc-shaped plate of the guide blades of the second-stage guide is 55°. The distance D between the bottom of the first-stage guide and the top of the second-stage guide is 1 / 2 of the total length L of the cyclone tube. This ensures that the liquid-containing gas flow can be continuously and stably accelerated and rotated by the guide throughout the entire length of the cyclone tube, which is beneficial for the centrifugal separation of droplets.

[0045] The preferred intermediate column has a bullet-shaped top and bottom, which can reduce flow resistance.

[0046] As shown in Figure 5, Figure 6 , Figure 7 and Figure 8 As shown: The strong swirling flow generated by the first-stage guide 10-2 throws the droplets toward the wall to form a liquid film. Under the combined action of the rotating airflow and gravity, the droplets pass through the second-stage guide 10-3 to form large droplets, which are then separated into the separation cone and collection chamber at the bottom.

[0047] like Figure 1As shown, the cavity within the outer casing between the third and fourth support plates constitutes a top drainage chamber. The coalescing filter module includes multiple coalescing filter elements 16, the lower part of which is fixedly connected to mounting holes on the fourth support plate. The coalescing filter elements are arranged vertically, and the coalescing filter elements 16 are commercially available (the coalescing filter elements 16 are currently industrially molded products). A top vent is provided on the outer casing at a position corresponding to the upper outlet of the coalescing filter element 16. The cavity within the outer casing between the fourth support plate and the end cap of the separator mounted on the top of the outer casing is the vent chamber 19. Figure 1 The top part is the end cap of the separator, which uses a quick-opening blind flange and is an industrial standard product.

[0048] An upper drain port 17 is provided on the outer casing corresponding to the lower part of the top drain chamber. A top vent port 18 is provided on the outer casing corresponding to the vent chamber 19.

[0049] The natural gas discharged from the multi-stage guide vane cyclone separator module still contains a small amount of tiny liquid droplets, which are captured and separated using multiple parallel coalescing filter elements 16. The captured liquid is discharged from the separator through the upper drain port 17, and the purified natural gas is collected in the exhaust chamber 19 and finally discharged from the separator through the top exhaust port 18.

Claims

1. A built-in multi-tube supersonic condensation-cyclone-coalescing filter, comprising a housing, characterized in that: Inside the outer shell, from bottom to top, are arranged a swirl pre-separation module, a supersonic nozzle steam condensation module, a multi-stage guide vane type droplet swirl separation module, and a coalescing filter module. Inside the outer shell, from bottom to top, are fixed a lower partition, an upper partition, a first support plate, a second support plate, a third support plate, and a fourth support plate. The outer walls of the upper partition, lower partition, first support plate, second support plate, third support plate, and fourth support plate are shaped to match the inner wall of the outer shell and are fixedly connected along the circumferential direction. The cyclone pre-separation module includes a drainage channel (5) connected at one end to a lower drainage port at the bottom of the outer shell. The cavity inside the outer shell between the upper and lower partitions forms a liquid accumulation chamber (4). A liquid accumulation outlet is opened on the outer shell corresponding to the lower part of the liquid accumulation chamber. A level gauge is installed on the outer shell corresponding to the liquid accumulation chamber. Multiple cyclone tubes arranged vertically are installed in the liquid accumulation chamber. Each cyclone tube includes a first cyclone tube cylinder (3-1) fixed to the upper partition. The top inlet of the first cyclone tube cylinder is connected to an opening corresponding to the upper partition. The bottom outlet of the flow tube cylinder is located above the lower partition plate; a swirl tube guide (3-2) is installed in the upper part of the first swirling tube cylinder; the cavity inside the outer shell between the upper partition plate and the first support plate constitutes the air inlet chamber (2); the bottom of the vertically arranged lower riser pipe (6) is fixed in the middle of the upper partition plate and communicates with the lower riser hole opened in the middle of the upper partition plate; the top of the lower riser pipe is fixed in the middle of the first support plate and communicates with the riser hole opened in the middle of the first support plate; an air inlet is opened on the outer shell corresponding to the lower part of the air inlet chamber; the separator inlet channel (1) is connected to the air inlet. The cavity inside the outer shell between the first support plate and the second support plate constitutes the nozzle inlet cavity (7). The supersonic nozzle steam condensation module includes multiple nozzles (8) arranged in the vertical direction. The second support plate has mounting holes that correspond one-to-one with the multiple nozzles. The mounting holes are fixed in the middle part of the nozzles. The multiple nozzles are in the shape of Laval nozzles. A single supersonic nozzle segment consists of a tapering section, a throat, a diverging section and a straight section from bottom to top. The multi-stage guide vane type droplet cyclone separation module includes a rising air pipe (13) that passes through a connection hole in the middle of the top of the third support plate (15). The rising air pipe is set vertically and fixed on the third support plate. The top wall of the small opening end of a truncated cone (9) is fixedly connected to the bottom inlet wall of the rising air pipe. The top wall of the liquid collection chamber (11) is fixedly connected to the bottom wall of the large opening end of the separation cone. The middle drain pipe (12) passes through the outer shell and is connected to the liquid outlet inlet on the bottom wall of the liquid collection chamber. The liquid collection chamber is located above multiple nozzles. Multiple guide vane swirl tubes (10) arranged vertically are evenly distributed along the outer circumference of the rising air pipe (13). Each guide vane swirl tube includes a second swirl tube body (10-1). A first-stage guide (10-2) and a second-stage guide (10-3) are respectively installed at the top inlet and the bottom outlet of the second swirl tube body. The bottom of the second swirl tube body is fixed on the separation cone and communicates with the separation cone. The outer wall of the second swirl tube body is fixed to the outer wall of the rising air pipe by a support rod (14). The cyclone tube guide, the first-stage guide, and the second-stage guide all include an intermediate column. Multiple guide blades are evenly connected along the circumferential direction on the side wall at the middle of the intermediate column. The upper part of the multiple guide blades is a vertical plate and the lower part is an arc-shaped plate. The cavity inside the outer shell between the third support plate and the fourth support plate constitutes the top drainage cavity. The coalescing filter module includes multiple coalescing filter elements (16) whose lower parts are fixedly connected to the mounting holes opened on the fourth support plate. The coalescing filter elements are arranged in a vertical direction. A top exhaust port is opened on the outer shell at the position corresponding to the upper outlet of the coalescing filter element. The cavity part inside the outer shell between the fourth support plate and the end cap of the separator installed on the top of the outer shell is the exhaust cavity (19). An upper drainage port (17) is opened on the outer shell corresponding to the lower part of the top drainage cavity. A top exhaust port (18) is opened on the outer shell corresponding to the exhaust cavity.

2. The built-in multi-tube supersonic condensation-cyclone-coalescing filter according to claim 1, characterized in that: The boundary line equation of the tapering segment is: In the formula: r cr r1 is the throat radius; r1 is the inlet radius of the supersonic nozzle; and L is the length of the convergent section of the supersonic nozzle.

3. The built-in multi-tube supersonic condensation-cyclone-coalescing filter according to claim 1 or 2, characterized in that: Multiple nozzles are evenly distributed along the same circumferential direction.

4. The built-in multi-tube supersonic condensation-cyclone-coalescing filter according to claim 3, characterized in that: The liquid collection chamber is hemispherical.

5. The built-in multi-tube supersonic condensation-cyclone-coalescing filter according to claim 4, characterized in that: The cyclone tube guide includes 6 guide vanes, each guide vane having an outlet angle of 42° with its arc plate. The first-stage guide and the second-stage guide each include 8 guide vanes. The first-stage guide has an outlet angle of 42° with its arc plate, and the second-stage guide has an outlet angle of 55° with its arc plate. The distance D between the bottom of the first-stage guide and the top of the second-stage guide is 1 / 2 of the total length L of the cyclone tube.

6. The built-in multi-tube supersonic condensation-cyclone-coalescing filter according to claim 5, characterized in that: The top and bottom of the intermediate column are bullet-shaped.

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