A natural gas pre-dehydration device

Abstract

This utility model belongs to the field of natural gas dehydration technology, and discloses a natural gas pre-dehydration device, including an overall shell, within which are connected a spiral acceleration section, a cyclone separation section, and a condensing filtration section. The spiral acceleration section has built-in tapered guide vanes, the inclination angle of which gradually decreases along the airflow direction. The cyclone separation section includes a double-cone structure and a liquid collection tank, with the double-cone structure connected to the liquid collection tank. The condensing filtration section includes a gradient-porous metal fiber felt and a hydrophobic coated corrugated plate, which can be alternately stacked. The surface of the tapered guide vanes is provided with a plurality of nano-scale hydrophobic micro-protrusions, which are equidistantly arranged along the spiral line of the tapered guide vanes. This utility model achieves efficient removal of submicron-level water mist without the need for chemical reagents through a multi-stage mechanical synergistic dehydration structure.

Description

Technical Field

[0001] This utility model relates to the field of natural gas dehydration technology, and in particular to a natural gas pre-dehydration device. Background Technology

[0002] A natural gas pre-dehydration unit is a device used to remove moisture from natural gas before compression. It is usually installed at the front end of the compressor (low-pressure end) and belongs to the pretreatment stage in the natural gas processing technology. It uses adsorption materials such as molecular sieves to deeply remove moisture from the raw natural gas, ensuring that the water content of the natural gas entering the compressor meets the standards (such as the standard for compressed natural gas for vehicles), avoiding the generation of condensate water during subsequent compression or storage, protecting the compressor and ensuring the safe operation of the system.

[0003] Traditional natural gas dehydration methods mostly employ triethylene glycol absorption or molecular sieve adsorption, which suffer from problems such as large equipment size, high energy consumption, and chemical pollution. For wellhead or pipeline pre-dehydration stages, existing mechanical separators are not efficient enough at capturing water mist particles with a diameter <10μm and are easily affected by airflow pulsation. Therefore, we propose a natural gas pre-dehydration device. Utility Model Content

[0004] In view of the problems that existing mechanical separators have insufficient efficiency in capturing water mist with a particle size of <10μm and are easily affected by airflow pulsation, this utility model is proposed.

[0005] Therefore, the purpose of this utility model is to provide a natural gas pre-dehydration device, which aims to achieve efficient removal of submicron-level water mist without the need for chemical agents through a multi-stage mechanical synergistic dehydration structure.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0007] A natural gas pre-dehydration device includes an integral shell, within which a spiral acceleration section, a cyclone separation section, and a condensation filtration section are coaxially connected.

[0008] The spiral acceleration section has built-in tapered guide vanes, the tilt angle of which gradually decreases along the airflow direction.

[0009] The cyclone separation section includes a double-cone structure and a liquid collection tank, and the double-cone structure is connected to the liquid collection tank;

[0010] The cohesive filtration section includes a gradient porous metal fiber felt and a hydrophobic coated corrugated plate, which can be alternately stacked.

[0011] As a technical solution of the natural gas pre-dehydration device of this utility model, the surface of the tapered guide vane is provided with a plurality of nano-scale hydrophobic micro-protrusion arrays, and the plurality of nano-scale hydrophobic micro-protrusion arrays are equidistantly arranged along the spiral line of the tapered guide vane.

[0012] As a technical solution of the natural gas pre-dehydration device of this utility model, wherein: a plurality of guide grooves are opened on the surface of the cone of the double cone structure, and the plurality of guide grooves are arranged radially.

[0013] As a technical solution of the natural gas pre-dehydration device of this utility model, the porosity of the gradient pore metal fiber felt gradually decreases along the airflow direction, and the fiber diameter of the gradient pore metal fiber felt gradually decreases along the airflow direction.

[0014] As a technical solution of the natural gas pre-dehydration device of this utility model, it further includes an elastic compensation chamber, which is disposed inside the overall shell and located between the cyclone separation section and the condensation filtration section. The elastic compensation chamber includes an annular corrugated pipe and a pre-tightening spring, with the pre-tightening spring embedded in the annular corrugated pipe.

[0015] As a technical solution of the natural gas pre-dehydration device of this utility model, the pre-tensioning spring can extend and retract along the axial direction of the annular corrugated pipe, and the stiffness coefficient of the pre-tensioning spring is 50-80N / mm.

[0016] As a technical solution of the natural gas pre-dehydration device of this utility model, a self-cleaning drain valve is installed at the end of the liquid collection tank away from the double cone structure. The valve core of the self-cleaning drain valve is made of polytetrafluoroethylene-silicon carbide composite material. The self-cleaning drain valve automatically opens when the liquid level in the liquid collection tank reaches one-third of the tank height.

[0017] As a technical solution of the natural gas pre-dehydration device of this utility model, the overall shell is made of duplex stainless steel, the inner wall of the overall shell is treated with shot peening, and the roughness Ra of the inner cavity of the overall shell is ≤0.8μm.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects:

[0019] 1. This utility model improves the capture efficiency of water mist with a particle size of <10μm by using a three-stage synergistic process of spiral acceleration pre-separation, cyclone centrifugal separation, and condensation filtration, solving the problem of low efficiency of traditional mechanical separators. At the same time, it can achieve efficient removal of submicron-level water mist without the need for chemical reagents.

[0020] 2. This utility model, by adopting the design of an elastic compensation chamber and a self-cleaning drain valve, can effectively cope with airflow pulsation and liquid level fluctuation to ensure continuous and stable operation, while also being able to adapt to complex wellhead conditions to improve the applicability of the device.

[0021] 3. This utility model, by using a gradient porous metal fiber felt that can be repeatedly washed and reused, can reduce energy consumption and waste pollution, while eliminating the consumption of chemical agents, thus meeting the requirements of green mining. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them:

[0023] Figure 1 This is a schematic diagram of the overall main structure of this utility model.

[0024] Figure 2 This is a schematic side view of the overall structure of this utility model.

[0025] Figure 3 This is a cross-sectional structural diagram of the present invention.

[0026] Figure 4 For the present utility model Figure 3 Enlarged structural diagram at point A in the middle.

[0027] Explanation of reference numerals in the attached figures:

[0028] In the figure: 1. Overall shell; 201. Gradient guide vane; 202. Nanoscale hydrophobic micro-protrusion array; 301. Double cone structure; 3011. Guide groove; 302. Liquid collection groove; 303. Self-cleaning drain valve; 401. Annular corrugated pipe; 402. Pre-tension spring; 501. Gradient porous metal fiber felt; 502. Hydrophobic coated corrugated plate. Detailed Implementation

[0029] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0030] Reference Figures 1-4 A natural gas pre-dehydration device is provided. The natural gas pre-dehydration device includes an integral shell 1. Inside the integral shell 1, a spiral acceleration section, a cyclone separation section and a condensation filtration section are coaxially connected. The integral shell 1 is connected to the natural gas pipeline by a connecting flange.

[0031] The spiral acceleration section has a built-in tapered guide vane 201, which is made of titanium alloy. The tilt angle of the tapered guide vane 201 gradually decreases along the airflow direction.

[0032] The cyclone separation section includes a double cone structure 301 and a liquid collection tank 302, and the double cone structure 301 is connected to the liquid collection tank 302. The double cone structure 301 is made of duplex stainless steel 2205.

[0033] The condensing filtration section includes a gradient porous metal fiber felt 501 and a hydrophobic coated corrugated plate 502. The gradient porous metal fiber felt 501 and the hydrophobic coated corrugated plate 502 can be stacked alternately. The corrugation angle of the hydrophobic coated corrugated plate 502 is 60 degrees, and the surface is coated with polydimethylsiloxane. In application, through the three-stage integrated design of the spiral acceleration section (gradient guide vanes 201), the swirl separation section (double cone structure 301 and liquid collection tank 302), and the condensing filtration section (gradient porous metal fiber felt 501 and hydrophobic coated corrugated plate 502), the liquid water in natural gas can be separated in stages. Compared with the traditional single separation method, it can improve efficiency and reduce equipment size.

[0034] Reference Figure 1 and Figure 3 The surface of the tapered guide vane 201 is provided with a number of nanoscale hydrophobic micro-protrusion arrays 202. The nanoscale hydrophobic micro-protrusion arrays 202 can be processed by laser etching process, and the number of nanoscale hydrophobic micro-protrusion arrays 202 are equidistantly arranged along the spiral line of the tapered guide vane 201. In application, the nanoscale hydrophobic micro-protrusion arrays 202 on the surface of the tapered guide vane 201 can reduce the droplet adhesion rate, reduce the formation of liquid film on the blade surface, make the droplets easier to be stripped by the airflow, and improve the pre-separation efficiency of the spiral acceleration section.

[0035] Reference Figure 3 The double-cone structure 301 has several guide grooves 3011 on its conical surface, and the guide grooves 3011 are arranged radially. In application, the radial guide grooves 3011 on the double-cone structure 301 guide the separated droplets to converge quickly into the collection tank 302, avoiding secondary entrainment of liquid due to turbulence, so as to improve the stability of separation.

[0036] Reference Figure 3 and Figure 4 The porosity of the gradient porosity metal fiber felt 501 gradually decreases along the airflow direction, and the fiber diameter of the gradient porosity metal fiber felt 501 gradually decreases along the airflow direction. In application, the design of the decreasing porosity and fiber diameter of the gradient porosity metal fiber felt 501 forms a multi-stage filtration gradient, which can improve the capture rate of water mist particles as small as 5μm.

[0037] Reference Figure 3 and Figure 4 It also includes an elastic compensation chamber, which is located inside the overall housing 1 and between the cyclone separation section and the condensation filtration section. The elastic compensation chamber includes an annular bellows 401 and a pre-tensioning spring 402. The annular bellows 401 is made of Inconel 625 material, and the pre-tensioning spring 402 is embedded in the annular bellows 401. The pre-tensioning spring 402 can extend and retract along the axial direction of the annular bellows 401, and the stiffness coefficient of the pre-tensioning spring 402 is 50-80 N / mm. In application, the elastic compensation chamber (annular bellows 401 and pre-tensioning spring 402) can absorb pressure fluctuations caused by airflow pulsation, maintain the working stability of the cyclone separation section and the condensation filtration section, and extend the filter media life.

[0038] Reference Figure 3 A self-cleaning drain valve 303 is installed at the end of the collection tank 302 away from the double cone structure 301. The self-cleaning drain valve 303 is existing technology and will not be described in detail here. The valve core of the self-cleaning drain valve 303 is made of polytetrafluoroethylene-silicon carbide composite material. When the liquid level in the collection tank 302 reaches one-third of the tank height, the self-cleaning drain valve 303 automatically opens. In application, the self-cleaning drain valve 303 uses a polytetrafluoroethylene-silicon carbide valve core, which has excellent wear resistance and hydrophobicity. Combined with the liquid level triggering mechanism, it can achieve automatic drainage without the risk of blockage, thereby extending the maintenance cycle.

[0039] Reference Figures 1-3 The overall shell 1 is made of duplex stainless steel. The inner wall of the overall shell 1 is treated with shot peening and the inner cavity roughness Ra≤0.8μm. In application, the duplex stainless steel shell and shot peening process improve the resistance to hydrogen sulfide corrosion. The inner cavity roughness ≤0.8μm can reduce flow resistance and is suitable for high sulfur natural gas environment.

[0040] The working principle of this utility model is as follows: First, natural gas enters the spiral acceleration section from the inlet. The tapered guide vanes 201 accelerate the airflow and form a spiral motion. Under the action of centrifugal force, droplets impact the surface of the vanes. The nano-scale hydrophobic micro-protrusion array 202 reduces liquid film adhesion. The initially separated droplets are transported downstream along the vanes. Then, the high-speed airflow enters the double-cone structure 301. Due to the sudden change in cross-sectional area, a strong swirling flow is generated. The droplets are thrown against the cone wall and flow into the collection tank 302 through the radial guide channels 3011. When the liquid level reaches 1 / 3 of the height, the self-cleaning drain valve 303 opens, and liquid water is discharged through the hydrophobic valve core to avoid particulate matter clogging. First, the airflow passes sequentially through a gradient porous metal fiber felt 501 and a hydrophobic coated corrugated plate 502, capturing 5-10μm droplets through inertial collision. The hydrophobic coated corrugated plate 502 promotes the agglomeration of droplets into larger particles to improve the removal rate. Before this, when the airflow passes through the elastic compensation cavity, the annular corrugated pipe 401 and the pre-tightening spring 402 absorb pressure fluctuations to maintain the pressure difference stability of the downstream condensation filtration section. Finally, the dehydrated natural gas enters the pipeline from the outlet, thereby improving the capture efficiency of water mist with a particle size <10μm and achieving efficient removal of submicron-level water mist without the need for chemical agents.

[0041] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A natural gas pre-position dehydration unit characterized by: It includes an overall shell (1), and a spiral acceleration section, a swirling separation section and a cohesive filtration section are coaxially connected inside the overall shell (1); The spiral acceleration section has a built-in tapered guide vane (201), the tilt angle of which gradually decreases along the airflow direction; The cyclone separation section includes a double cone structure (301) and a liquid collection tank (302), and the double cone structure (301) is connected to the liquid collection tank (302); The cohesive filtration section includes a gradient porous metal fiber felt (501) and a hydrophobic coated corrugated plate (502), which can be alternately stacked.

2. The natural gas pre-dehydration device according to claim 1, characterized in that: The surface of the tapered guide vane (201) is provided with a plurality of nanoscale hydrophobic micro-protrusion arrays (202), and the plurality of nanoscale hydrophobic micro-protrusion arrays (202) are equidistantly arranged along the spiral line of the tapered guide vane (201).

3. The natural gas pre-dehydration device according to claim 1, characterized in that: The double cone structure (301) has a plurality of flow guide grooves (3011) on its cone surface, and the plurality of flow guide grooves (3011) are arranged radially.

4. The natural gas pre-dehydration device according to claim 1, characterized in that: The porosity of the gradient porous metal fiber felt (501) gradually decreases along the airflow direction, and the fiber diameter of the gradient porous metal fiber felt (501) gradually decreases along the airflow direction.

5. The natural gas pre-dehydration device according to claim 1, characterized in that: It also includes an elastic compensation cavity, which is located inside the overall shell (1) and between the swirl separation section and the coagulation filtration section. The elastic compensation cavity includes an annular corrugated pipe (401) and a pre-tensioning spring (402), which is embedded in the annular corrugated pipe (401).

6. The natural gas pre-dehydration device according to claim 5, characterized in that: The preload spring (402) can extend and retract along the axial direction of the annular bellows (401), and the stiffness coefficient of the preload spring (402) is 50-80 N / mm.

7. The natural gas pre-dehydration device according to claim 1, characterized in that: A self-cleaning drain valve (303) is installed at the end of the liquid collection tank (302) away from the double cone structure (301). The valve core of the self-cleaning drain valve (303) is made of polytetrafluoroethylene-silicon carbide composite material. The self-cleaning drain valve (303) automatically opens when the liquid level of the liquid collection tank (302) reaches one-third of the tank height.

8. The natural gas pre-dehydration device according to claim 1, characterized in that: The overall shell (1) is made of duplex stainless steel. The inner wall of the overall shell (1) is treated with shot peening and the roughness Ra of the inner cavity of the overall shell (1) is ≤0.8μm.

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