Four-section type gas-liquid cyclone separation pipe

Abstract

The invention provides a four-section type gas-liquid cyclone separation pipe, and relates to the technical field of separation, the four-section type gas-liquid cyclone separation pipe comprises a core pipe with holes as well as a liquid phase storage section, a cyclone section, a transition section and a gas phase fine separation section which are communicated in sequence, and one end of the core pipe with holes is connected with fins, enters from the gas phase fine separation section and is positioned in the middle of the cyclone section; a plurality of fins are evenly connected to the outer circle of the core pipe with the hole at intervals, a cross-shaped vortex preventing device is connected into the bottom of the liquid phase storage section, a conical end socket is connected to the bottom of the liquid phase storage section, a bent pipe is connected to the top of the gas phase fine separation section, and the bent pipe is communicated with the other end of the core pipe with the hole. The problems that a separator in the prior art is large in energy consumption, poor in separation efficiency and short in service life are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of separation technology, in particular to a four-section gas-liquid cyclone separation tube. BACKGROUND

[0002] In the process of oil and gas field exploitation, gas-liquid separation is a crucial link, and its separation effect directly affects the normal operation of subsequent processes and the service life of equipment. However, the traditional cyclone separator has a length-diameter ratio (L / D) generally > 10:1, which results in a long flow path of fluid in the separator and large frictional resistance, causing high pressure drop (> 8 kPa) and increasing energy consumption and reducing operation economy. On the other hand, the separation efficiency for liquid droplets above 50 μm is less than 85%, and the gas entrainment rate is > 5%, which cannot meet the higher requirements of downstream processes for gas-liquid quality. Moreover, in a high-sulfur environment, the corrosion resistance of the traditional separator is weak, and the service life is usually < 3 years, which requires frequent replacement, increasing production costs and maintenance workload. SUMMARY

[0003] The present application aims to provide a four-section gas-liquid cyclone separation tube, which solves the problems of large energy consumption, poor separation efficiency and short service life of the separator in the prior art.

[0004] The technical scheme of the present application is as follows:

[0005] The present application provides a four-section gas-liquid cyclone separation tube, which comprises a perforated core tube and a liquid phase storage section, a cyclone section, a transition section and a gas phase fine separation section connected in sequence. The perforated core tube is connected at one end with fins, and this end enters the gas phase fine separation section and is located in the middle of the cyclone section. A plurality of fins are uniformly spaced and connected to the outer circle of the perforated core tube. A cross vortex preventer is connected inside the bottom of the liquid phase storage section. A conical head is connected to the bottom of the liquid phase storage section. A bend pipe is connected to the top of the gas phase fine separation section. The bend pipe is in communication with the other end of the perforated core tube.

[0006] Further, the perforated core tube is a conical tube with an opening rate of 25% and a taper angle of 15°.

[0007] Further, the thickness of the fin is 4 mm, and the axial spacing between adjacent two fins is 50 mm.

[0008] Further, the diameter of the liquid phase storage section is 150 mm, the length is 1200 mm, the angle of the conical head is 60°, and the thickness of the cross vortex preventer is 8 mm. The length-diameter ratio of the cyclone section is 5:1. The taper angle of the transition section is 15°, and the length is 300 mm. The diameter of the gas phase fine separation section is 150 mm, and the length is 1000 mm. The bend pipe has an elevation angle of 35° and a curvature radius of 300 mm.

[0009] Further, the diameter of the cyclone section is 150 mm, and the length is 2000 mm.

[0010] Further, the rib is made of duplex stainless steel.

[0011] Further, the number of the ribs is 6.

[0012] Further, the pipe body material of the separation pipe is 09CrCuSb steel, and the element percentage composition is: 0 < C ≤ 0.12%, 0.8% ≤ Cr ≤ 1.2%, 0.25% ≤ Cu ≤ 0.5%, 0.04% ≤ Sb ≤ 0.1%, 0 < P ≤ 0.035%, 0 < S ≤ 0.03%.

[0013] According to the above technical features, the beneficial effects of the present application are: the present application provides a four-section gas-liquid cyclone separation pipe, which is optimized in structure and flow field with low length-diameter ratio to improve separation efficiency, including a liquid phase storage section, a cyclone section, a transition section and a gas phase fine separation section, the length-diameter ratio L / D of the cyclone section is 5:1, the low length-diameter ratio shortens the flow channel, reduces the flow time and friction resistance of the fluid in the separator, and can reduce the friction pressure drop; and the built-in rib and the hole core pipe are made of 09CrCuSb steel material which is resistant to hydrogen sulfide stress corrosion, and have excellent corrosion resistance, which can prolong the service life of the equipment. When working, the gas-liquid mixture enters the cyclone section tangentially at a certain flow rate, the flow field is strengthened by the rib and the hole core pipe, and high-efficiency separation is realized. The present application solves the problems of high pressure drop, low separation efficiency and weak corrosion resistance of the traditional cyclone separator, and is suitable for high-sulfur (H2S ≥ 1000 ppm) and high-temperature (55-75℃) harsh working conditions. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a structural schematic diagram of the present application;

[0015] Figure 2 is a schematic diagram of the cyclone section in the structure of the present application.

[0016] In the figure:

[0017] 1-liquid phase storage section; 2-cyclone section; 3-transition section; 4-gas phase fine separation section; 5-hole core pipe; 6-rib; 7-cross anti-vortex device; 8-elbow. DETAILED DESCRIPTION

[0018] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present application.

[0020] Embodiments

[0021] Referring to Figures 1-2 The embodiments of the present application provide a four-section gas-liquid cyclone separation tube, which can realize high separation efficiency, low system pressure drop and strong corrosion resistance by optimizing structure and material selection. The structure specifically comprises a perforated core tube 5 and sequentially connected liquid phase storage section 1, cyclone section 2, transition section 3 and gas phase fine separation section 4. The perforated core tube 5 is connected with a rib 6 at one end, and the end enters the gas phase fine separation section 4 and is located in the middle of the cyclone section 2. A plurality of ribs 6 are uniformly connected to the outer circle of the perforated core tube 5. A cross vortex preventer 7 is connected to the bottom of the liquid phase storage section 1. The bottom of the liquid phase storage section 1 is connected with a conical head. The top of the gas phase fine separation section 4 is connected with an elbow 8, which is in communication with the other end of the perforated core tube 5.

[0022] It is worth noting that the four-section gas-liquid cyclone separation tube provided by the embodiments of the present application comprises a liquid phase storage section 1, a cyclone section 2, a transition section 3 and a gas phase fine separation section 4. In detail, the diameter of the liquid phase storage section 1 is 150 mm, and the length is 1200 mm. The bottom is connected with a 60° conical head and a cross vortex preventer 7 with a thickness of 8 mm. The conical head can make the liquid quickly converge and discharge, avoiding affecting the separation effect due to liquid retention. The cross vortex preventer 7 is fixed inside the conical head, which is used to prevent the liquid from forming vortex during discharge, thereby avoiding interference with the relative gas-liquid separation process. Preferably, the cross vortex preventer 7 is made of high-strength stainless steel material, which can ensure that it will not fail due to mechanical stress or corrosion in long-term operation.

[0023] Further, the cyclone section 2 has a diameter of 150 mm and a length of 2000 mm, a length-diameter ratio L / D = 5:1, and is connected with 6 rib plates 6 and a perforated core pipe 5. The rib plate 6 has a thickness of 4 mm and an axial spacing of 50 mm, and is preferably made of 2205 duplex stainless steel. The plurality of rib plates 6 are uniformly distributed in the circumferential direction and are fixedly connected to the outer wall of the perforated core pipe 5. The rib plate 6 can enhance the turbulence intensity of the fluid, improve the centrifugal force gradient, and promote the separation of the gas-liquid two-phase under the action of the centrifugal force. The perforated core pipe 5 is a perforated core pipe 5, one end of which is located at the center of the cyclone section 2, has an opening rate of 25% and a taper angle of 15°, and can be fixed by bolts. The perforated core pipe 5 can stabilize the cyclone field and suppress the vortex phenomenon of the gas phase, thereby reducing the probability of liquid entrainment by the gas phase. Through CFD simulation tests, the applicant determines that the device can reduce the gas entrainment rate by ≥30%.

[0024] Further, the transition section 3 has a taper angle of 15° and a length of 300 mm, and adopts a tapered structure to achieve smooth transition from the cyclone section 2 to the gas phase fine separation section 4. The transition section 3 can reduce the flow resistance of the fluid and reduce the system pressure drop.

[0025] Further, the gas phase fine separation section 4 has a diameter of 150 mm and a length of 1000 mm, and is connected at the top with an elbow pipe 8 having an upward angle of 35°. The elbow pipe 8 has a curvature radius of 300 mm. The elbow pipe 8 can generate a secondary centrifugal effect when the gas phase passes through the elbow pipe 8, remove the small droplets in the gas phase, effectively capture residual droplets, and further improve the quality of the gas phase.

[0026] Further, the pipe body of the separation pipe is preferably made of 09CrCuSb steel resistant to hydrogen sulfide stress corrosion, and has the following element percentage composition: 0 < C ≤ 0.12%, 0.8% ≤ Cr ≤ 1.2%, 0.25% ≤ Cu ≤ 0.5%, 0.04% ≤ Sb ≤ 0.1%, 0 < P ≤ 0.035%, and 0 < S ≤ 0.03%. In detail, after quenching and tempering treatment, the pipe body has a hardness of ≤22HRC, which meets the NACEMR0175 / ISO15156 standard. The material used in the separation pipe has a corrosion rate of ≤0.01 mm / year in a 15000 ppm H2S environment, has excellent corrosion resistance, can prolong the service life of the equipment, and ensure the long-term stability of the equipment under high-sulfur working conditions.

[0027] It should be noted that the separation tube provided by the application, in use: the gas-liquid mixture enters the cyclone section 2 in a tangential manner, the gas phase flow rate is controlled at 15-18 m / s, the liquid phase flow rate is controlled at 1.2-1.5 m / s, the precise control of the inlet flow rate ensures the separation effect of the gas-liquid two-phase in the cyclone section 2, the ribs 6 induce turbulence of the fluid, improve the centrifugal force gradient, and make the gas-liquid two-phase separate under the action of the centrifugal force; then, the perforated core tube 5 stabilizes the cyclone field, suppresses the gas phase vortex phenomenon, and reduces the probability of gas phase entraining liquid; then, the liquid phase settles along the pipe wall to the liquid phase storage section 1 under the action of the centrifugal force, and the gas rises to the gas phase fine separation section 4 through the transition section 3 for further processing.

[0028] It should be noted that the separation tube provided by the application, in use: the liquid level is maintained at 50±5% through PID closed-loop control, the response time is ≤3s, the liquid level control system adjusts the liquid discharge amount by monitoring the liquid level change in real time, ensures the stable operation of the device, and avoids the influence of abnormal liquid level on the separation effect. In detail, when the H2S concentration ≥20ppm, the emergency shutdown device is triggered, the response time is ≤1s, and the safety of the device and personnel is ensured; the emergency shutdown device is realized through the quick response valve installed at the inlet, and the action is triggered by the control system according to the H2S concentration sensor signal.

[0029] It should be noted that the separation tube provided by the application, the length-diameter ratio of the cyclone section 2 is compressed to 5:1, compared with the length-diameter ratio >10:1 of the traditional cyclone separator, the flow channel length can be shortened, the flow time and friction resistance of the fluid in the separator can be reduced, the system pressure drop is reduced to ≤3.2kPa, which is reduced by 60% compared with the traditional equipment. The combination of the ribs 6 and the perforated core tube 5 enhances the turbulence intensity and stabilizes the cyclone field, so that the gas entrainment rate is reduced by ≥30%, the applicant performs CFD simulation test, and the separation efficiency of 50μm droplets reaches ≥90%, which is improved by 5.9% compared with the traditional equipment. In order to determine the use effect of the separation tube provided by the application, the applicant performs a plurality of tests, and a group of test results are shown in the following table:

[0030] Indicator The invention Conventional apparatus Lift amplitude 50 pm droplet separation efficiency ≥90% ≤85% +5.9% Gas phase entrainment rate ≤2.5% ≥5% Reduced by 50% System pressure drop ≤ 3.2 kPa ≥ 8 kPa Reduced by 60%

[0031] It should be noted that the application examples of an oilfield show that under the working conditions of H2S=5000ppm, temperature 55℃, treatment capacity 100m 3 / d liquid + 10×10 4 Nm 3 / d gas, the separation efficiency of the separation tube reaches 92.3%, the gas phase entrainment rate is 2.1%, and both are better than the design index. The system pressure drop is 3.0kPa, and the energy saving rate reaches 37% compared with the traditional equipment. After 720 hours of salt spray test, there is no coating failure phenomenon, which shows that the separation tube has good corrosion resistance and stability.

[0032] It should be noted that the separation tube provided by the application compresses the length-diameter ratio of the cyclone section 2 to 5:1, and integrates the rib 6 and the hole core pipe 5, thereby breaking through the limitation of high length-diameter ratio of the traditional cyclone separator, effectively reducing the system pressure drop while ensuring the separation efficiency; when in use, the stability problem in the separation process is solved and the reliability of the separation effect is improved by precisely controlling the tangential inlet flow rate of the gas-liquid two-phase (the gas phase is 15-18 m / s, and the liquid phase is 1.2-1.5 m / s) and realizing the PID closed-loop regulation and control of the liquid level rapid response (≤3s).

[0033] It should be noted that the remaining structure belongs to the prior art and will not be described in detail here.

[0034] The above shows and describes the basic principles and main features of the application and the advantages of the application, and it is obvious to those skilled in the art that the application is not limited to the details of the above exemplary embodiments, and the application can be implemented in other specific forms without departing from the spirit or essential characteristics of the application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, and the scope of the application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the application. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0035] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description manner of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A four-stage gas-liquid cyclone separation tube, characterized by, The application relates to a separation tube. The separation tube comprises a perforated core pipe (5) and sequentially connected liquid-phase storage section (1), cyclone section (2), transition section (3) and gas-phase fine separation section (4), one end of the perforated core pipe (5) is connected with a fin (6), the end enters the gas-phase fine separation section (4) and is located in the middle of the cyclone section (2), a plurality of fins (6) are uniformly connected to the outer circle of the perforated core pipe (5), a cross vortex preventer (7) is connected to the bottom of the liquid-phase storage section (1), a conical head is connected to the bottom of the liquid-phase storage section (1), a bend pipe (8) is connected to the top of the gas-phase fine separation section (4), and the bend pipe (8) is communicated with the other end of the perforated core pipe (5).

2. The separation tube of claim 1, wherein, The perforated core pipe (5) is a conical pipe, the opening rate is 25%, and the taper angle is 15 DEG.

3. The separation tube of claim 1, wherein, The thickness of the fin (6) is 4mm, and the axial spacing between two adjacent fins (6) is 50mm.

4. The separation tube of claim 1, wherein, The diameter of the liquid-phase storage section (1) is 150mm, the length is 1200mm, the angle of the conical head is 60 DEG, the thickness of the cross vortex preventer (7) is 8mm, the length-diameter ratio of the cyclone section (2) is 5:1, the taper angle of the transition section (3) is 15 DEG, the length is 300mm, the diameter of the gas-phase fine separation section (4) is 150mm, and the length is 1000mm. The bend pipe (8) is 35 DEG in elevation angle and has a curvature radius of 300mm.

5. The separation tube of claim 4, wherein, The diameter of the cyclone section (2) is 150mm, and the length is 2000mm.

6. The separation tube of claim 1, wherein, The fin (6) is made of duplex stainless steel.

7. The separation tube of claim 1, wherein, The number of the fin (6) is six.

8. The separation tube of claim 1, wherein, The pipe body material of the separation tube is 09CrCuSb steel, and the element percentage composition is as follows: 0 < C <= 0.12%, 0.8% <= Cr <= 1.2%, 0.25% <= Cu <= 0.5%, 0.04% <= Sb <= 0.1%, 0 < P <= 0.035%, and 0 < S <= 0.03%.

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