An efficient natural gas separation device
By combining horizontal and vertical separators, the problem of low separation efficiency of impurities in natural gas has been solved, achieving efficient separation and resource recovery, reducing maintenance costs, and ensuring stable operation of the compressor.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHAANXI YUYANG PETROLEUM TECH ENG CO LTD
- Filing Date
- 2025-08-26
- Publication Date
- 2026-07-14
AI Technical Summary
During natural gas extraction and gathering, the lack of defoaming devices allows impurities such as foam, water, and sand to enter the integrated natural gas processing unit, causing the separator to operate under overload, the compressor to frequently shut down at high liquid levels, and increasing maintenance costs.
The separation system employs a combination of horizontal and vertical separators, along with internal component design, including an inlet distribution pipe, momentum absorber, flow stabilizer, defoaming element, and tubular filter element, to achieve efficient separation of impurities from natural gas.
It significantly improved the quality and purity of natural gas, reduced the impact on downstream equipment, lowered maintenance costs, and enabled the safe and stable operation of the compressor and the recycling of resources.
Smart Images
Figure CN224494113U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of natural gas gathering, transmission and processing technology in gas field surface engineering, and more specifically, to a high-efficiency natural gas separation device. Background Technology
[0002] Natural gas extraction often involves liquids (such as water and condensate) and solid impurities.
[0003] During the gas field gathering and transportation process, due to the large fluctuations in the upstream gas volume and the frequent slug flow, the lack of a "defoaming" device before entering the integrated natural gas unit causes a large amount of foam, water, and sand to directly enter the integrated natural gas unit along with the natural gas. This results in the separator of the integrated natural gas unit operating under overload conditions. Water, sand, foam, impurities, etc., cannot be separated in time and flow into the downstream compressor system with the natural gas, causing frequent high-liquid-level shutdowns of the compressor. This causes inconvenience to the production and operation of the gas gathering station and generates a large amount of maintenance costs.
[0004] Therefore, the development of an efficient, reliable, and economical natural gas separation system and process is of great practical significance. Utility Model Content
[0005] In view of this, this application provides a highly efficient natural gas separation device.
[0006] The embodiments of this application are implemented as follows:
[0007] In one aspect, this application provides a high-efficiency natural gas separation device, including a horizontal separator, a vertical separator, a compressor, a flash tank, a wastewater tank, a sand box, a gas pipeline, a liquid pipeline, and a vent pipeline:
[0008] The gas outlet of the horizontal separator is connected to the gas inlet of the vertical separator via a gas pipeline;
[0009] The gas outlet of the vertical separator is connected to the air inlet of the compressor via a gas pipeline;
[0010] The bottom liquid outlet of the horizontal separator is connected to the sand box via a liquid pipe;
[0011] The bottom liquid outlet of the vertical separator merges with the bottom liquid outlet of the horizontal separator, and is then connected to the liquid inlet of the flash tank via a liquid pipeline.
[0012] The top gas outlet of the flash tank is connected to a vent pipe, and the bottom liquid outlet of the flash tank is connected to the inlet of the wastewater tank through a liquid pipe.
[0013] The top of the horizontal separator, vertical separator, and flash tank are all equipped with safety valves, and the outlets of the safety valves are all connected to vent pipes.
[0014] In one possible implementation, the horizontal separator is a primary pre-separator;
[0015] Inside the horizontal separator, along the airflow direction, an air inlet distribution pipe, a momentum absorber, a flow stabilizer, and a first end interception device are arranged sequentially.
[0016] The air inlet distribution pipe is connected to the gas inlet of the horizontal separator, and the first end interception device is connected to the gas outlet of the horizontal separator.
[0017] In one possible implementation, the vertical separator is a two-stage fine separator;
[0018] Inside the vertical separator, along the airflow direction, a gas channel, a defoaming element, a tubular filter element, and a second end interception device are arranged sequentially.
[0019] The gas channel is connected to the gas inlet of the vertical separator, and the second end interception device is connected to the gas outlet of the vertical separator.
[0020] In one possible implementation, the compressor has a first filter at its inlet, which is a mesh cone filter. The inlet of the first filter is connected to the gas outlet of a vertical separator via a gas pipe. The compressor's outlet is connected in sequence to a flow meter and a gate valve via a gas pipe.
[0021] In one possible implementation, a manual gate valve is provided on the liquid pipeline between the bottom liquid outlet of the horizontal separator and the sand box.
[0022] In one possible implementation, a second filter and a check valve are provided on the common liquid pipeline where the bottom liquid outlets of the horizontal separator and the vertical separator merge. The check valve is located downstream of the second filter, and the outlet end of the common liquid pipeline is connected to the inlet of the flash tank.
[0023] In one possible implementation, the top gas outlet of the flash tank is connected to a flare system or the atmosphere via a vent pipe, and the bottom liquid outlet of the flash tank is connected to the top liquid inlet of a wastewater tank via a liquid pipe.
[0024] In one possible implementation, the vent pipe is connected to the safety valve outlet at the top of the horizontal separator, the vertical separator, and the flash tank, respectively.
[0025] In one possible implementation, a bypass gas pipeline is connected in parallel between the gas pipelines of the horizontal separator and the vertical separator, and a gate valve is provided on the bypass gas pipeline to realize the series connection or bypass isolation between the horizontal separator and the vertical separator.
[0026] In one possible implementation, the bottom of the horizontal separator is a conical structure, with a liquid outlet at the lowest point of the cone, and the liquid outlet is connected to the sand box via a liquid pipe.
[0027] The technical solution provided in this application can achieve at least the following beneficial effects:
[0028] This application provides a high-efficiency natural gas separation device that, through the synergistic effect of horizontal and vertical separators and the optimized design of internal components, can achieve efficient separation of various impurities in natural gas. In particular, it is highly effective in separating tiny droplets, foam, solid particles, and oily impurities, ensuring the safe and stable operation of the downstream compressor. Attached Figure Description
[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0030] Figure 1 This is a schematic diagram of the overall structure of a high-efficiency natural gas separation device shown in an exemplary embodiment of this application;
[0031] Figure 2 This is a schematic diagram of the internal structure of a horizontal separator shown in an exemplary embodiment of this application;
[0032] Figure 3 This is a schematic diagram of the internal structure of a vertical separator shown in an exemplary embodiment of this application.
[0033] Figure label:
[0034] 1. Horizontal separator; 2. Vertical separator; 3. Compressor; 4. Flash tank; 5. Wastewater tank; 6. Sand box; 7. Second filter; 8. Flow meter; 9. Gate valve; 10. Gas pipeline; 11. Liquid pipeline; 12. First filter; 13. Check valve; 110. First end interception device; 120. Momentum absorber; 130. Flow stabilizer; 210. Second end interception device; 220. Tubular filter element; 230. Defoaming element; 240. Gas passage. Detailed Implementation
[0035] To make the objectives, implementation methods and advantages of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the exemplary embodiments described are only some embodiments of this application, and not all embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.
[0036] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.
[0037] The terms "first," "second," "third," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar or related objects or entities, and do not necessarily imply a specific order or sequence, unless otherwise specified. It should be understood that such terms are interchangeable where appropriate.
[0038] The terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device that includes a range of components is not necessarily limited to all of the components that are clearly listed, but may include other components that are not clearly listed or that are inherent to such product or device.
[0039] Before explaining the efficient natural gas separation device provided in the embodiments of this application, the application scenarios and implementation environment of the embodiments of this application will be introduced first.
[0040] Natural gas extraction often involves liquids (such as water and condensate) and solid impurities.
[0041] During the gas field gathering and transportation process, due to the large fluctuations in the upstream gas volume and the frequent slug flow, the lack of a "defoaming" device before entering the integrated natural gas unit causes a large amount of foam, water, and sand to directly enter the integrated natural gas unit along with the natural gas. This results in the separator of the integrated natural gas unit operating under overload conditions. Water, sand, foam, impurities, etc., cannot be separated in time and flow into the downstream compressor system with the natural gas, causing frequent high-liquid-level shutdowns of the compressor. This causes inconvenience to the production and operation of the gas gathering station and generates a large amount of maintenance costs.
[0042] Therefore, the development of an efficient, reliable, and economical natural gas separation system and process is of great practical significance.
[0043] Next, the technical solutions of this application and how they solve the aforementioned technical problems will be described in detail through embodiments and in conjunction with the accompanying drawings. The embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application.
[0044] In one exemplary embodiment, such as Figure 1 As shown, a high-efficiency natural gas separation device is provided. In this embodiment, the device includes a horizontal separator 1, a vertical separator 2, a compressor 3, a flash tank 4, a wastewater tank 5, a sand box 6, a gas pipeline 10, a liquid pipeline 11, and a vent pipeline.
[0045] The gas outlet of the horizontal separator 1 is connected to the gas inlet of the vertical separator 2 via a gas pipe 10.
[0046] The gas outlet of the vertical separator 2 is connected to the air inlet of the compressor 3 via a gas pipe 10.
[0047] The bottom liquid outlet of the horizontal separator 1 is connected to the sand box 6 via a liquid pipe 11;
[0048] The bottom liquid outlet of the vertical separator 2 merges with the bottom liquid outlet of the horizontal separator 1, and is then connected to the liquid inlet of the flash tank 4 through the liquid pipe 11.
[0049] The top gas outlet of the flash tank 4 is connected to the vent pipe, and the bottom liquid outlet of the flash tank 4 is connected to the liquid inlet of the sewage tank 5 through the liquid pipe 11.
[0050] The top of the horizontal separator 1, the vertical separator 2, and the flash tank 4 are all equipped with safety valves, and the outlets of the safety valves are all connected to the vent pipes.
[0051] In one embodiment, the efficient natural gas separation device consists of a horizontal separator 1, a vertical separator 2, a compressor 3, a flash tank 4, a wastewater tank 5, a sand box 6, a gas pipeline 10, a liquid pipeline 11, and a venting pipeline.
[0052] Its gas path is:
[0053] Upstream gas → Gas inlet of horizontal separator 1 → Gas outlet of horizontal separator 1 → Gas pipeline 10 → Gas inlet of vertical separator 2 → Gas outlet of vertical separator 2 → Gas pipeline 10 → Air inlet of compressor 3 → Air outlet of compressor 3 → Gas pipeline 10 (with flow meter 8 and gate valve 9) → Downstream pipeline network.
[0054] Its liquid-solid path is as follows:
[0055] a) Liquid outlet at the conical bottom of horizontal separator 1 → manual gate valve 9 → liquid pipeline 11 → sand box 6;
[0056] b) The bottom liquid outlets of the horizontal separator 1 and the vertical separator 2 are connected to a common liquid pipeline 11 after passing through independent branch pipes. The pipeline 11 leads to the second filter 7, the check valve 13, and the inlet of the flash tank 4.
[0057] c) Liquid outlet at the bottom of flash tank 4 → liquid pipe 11 → liquid inlet at the top of wastewater tank 5.
[0058] Its leakage path is:
[0059] Safety valves are installed at the top of the horizontal separator 1, the vertical separator 2, and the flash tank 4. The outlets of each safety valve are connected to the vent pipes, which ultimately lead to the flare or the atmosphere.
[0060] In one possible implementation, the horizontal separator 1 is a primary pre-separator;
[0061] Inside the horizontal separator 1, along the airflow direction, an air inlet distribution pipe, a momentum absorber 120, a flow stabilizer 130, and a first end interception device 110 are arranged sequentially.
[0062] The air intake distribution pipe is connected to the gas inlet of the horizontal separator 1, and the first end interception device 110 is connected to the gas outlet of the horizontal separator 1.
[0063] In one embodiment, the horizontal separator 1 is a primary pre-separator. Its shell is a horizontal cylindrical shape with a diameter of 1.6-2.2m and a length of 5-9.6m. The design pressure is 6.3MPa. The lower side of its shell is integrally hot-pressed into a 60° cone shape, and the tip of the cone is connected to a DN80 drain pipe. The flange welded to the outside of the short pipe is connected to the flange of the manual gate valve 9. After the valve, it is connected to the sand box 6 through a DN80 liquid pipeline 11. A DN50 spring-loaded full-lift safety valve is also installed on the top end of the shell through a flange.
[0064] The internal components of the horizontal separator 1 are arranged sequentially along the airflow direction as follows:
[0065] Air inlet distribution pipe: welded to the inside of the end cap, it is a multi-hole horizontal pipe with evenly distributed φ10-20mm small holes to ensure that the incoming air enters the liquid surface uniformly.
[0066] Momentum absorber 120: a bowl-shaped porous baffle, facing the outlet of the air inlet distribution pipe, with a pore size of 5-10mm and an opening rate of 30-50%, used to absorb high-speed airflow and initially separate droplets and sand particles with a particle size ≥100μm.
[0067] Flow stabilizer 130: Composed of 3-5 vertical parallel corrugated plates with a plate spacing of 50-100mm and a plate length of 700-1200mm, welded to the inner wall of the shell, used to stabilize airflow and prolong settling time.
[0068] First end interception device 110: wire mesh demister, thickness ≥200mm, installed before the gas outlet, to intercept residual droplets ≥10μm.
[0069] In one possible implementation, the vertical separator 2 is a two-stage fine separator;
[0070] Inside the vertical separator 2, along the airflow direction, a gas channel, a defoaming element 230, a tubular filter element 220, and a second end interception device 210 are arranged sequentially.
[0071] The gas channel is connected to the gas inlet of the vertical separator 2, and the second end interception device 210 is connected to the gas outlet of the vertical separator 2.
[0072] In one embodiment, the vertical separator 2 is a two-stage fine separator. Its shell is a vertical cylinder with a diameter of 1.2m and a straight section height of 4-6m. The design pressure is 6.3MPa. A conical head is provided at the bottom of its shell, and the tip of the cone is connected to a DN50 drain port. The drain port and the drain branch pipe of the horizontal separator 1 merge into a common liquid pipeline 11. A DN40 spring-loaded full-opening safety valve is also installed on the top end of the shell through a flange.
[0073] The internal components of the vertical separator 2 are arranged from bottom to top as follows:
[0074] Gas channel: Tangential inlet volute, forming a swirling flow, causing droplets with a diameter ≥10μm to settle by centrifugation.
[0075] Defoaming element 230: a multi-channel corrugated plate assembly with a height of 200mm and a corrugated plate spacing of 5-8mm, welded and fixed to the inner wall of the cylinder, used to break up foam.
[0076] Tubular filter element 220: Length 800-1200mm, pleated glass fiber / polyester blended filter media, filtration accuracy 10μm, the top of the filter element is pressed by a quick-opening blind plate, and a liquid collection tray is provided at the bottom.
[0077] Second terminal interception device 210: wire mesh demister, thickness ≥300mm, installed above the filter element, to ultimately intercept residual droplets.
[0078] In one possible implementation, the compressor 3 is provided with a second filter 7 at its air inlet. The second filter 7 is a mesh cone filter. The inlet of the second filter 7 is connected to the gas outlet of the vertical separator 2 through a gas pipe 10. The air outlet of the compressor 3 is connected in sequence to a flow meter 8 and a gate valve 9 through a gas pipe 10.
[0079] In one embodiment, compressor 3 is a screw type with a rated capacity of 80×104 Nm3 / d, and it comes with its own buffer tank and control system. The flange at the air inlet of compressor 3 is connected to the second filter 7, which is a screen-type conical filter with a screen precision of 200 mesh. The conical structure facilitates chip removal. After the air outlet flange of compressor 3, flow meter 8 (vortex or ultrasonic) and gate valve 9 are welded in sequence, and then connected to the downstream high-pressure pipeline.
[0080] In one possible implementation, a first filter 12 and a check valve 13 are provided on the common liquid pipeline 11 after the bottom liquid outlets of the horizontal separator 1 and the vertical separator 2 merge. The check valve 13 is located downstream of the first filter 12, and the outlet end of the common liquid pipeline 11 is connected to the liquid inlet of the flash tank 4.
[0081] In one embodiment, the first filter 12 on the common liquid pipeline 11 is a Y-type filter with a carbon steel shell and a stainless steel filter element, which can be disassembled and cleaned online. The check valve 13 is a swing type, with a flange connected downstream of the first filter 12 to prevent gas or liquid in the flash tank 4 from flowing back into the separator.
[0082] In one possible implementation, the top gas outlet of the flash tank 4 is connected to the flare system or the atmosphere via a vent pipe, and the bottom liquid outlet of the flash tank 4 is connected to the top liquid inlet of the wastewater tank 5 via a liquid pipe 11.
[0083] In one embodiment, the shell of the flash tank 4 is a vertical cylindrical shell with a volume of 10m³. 3 The design pressure is 6.3MPa. Its liquid inlet is located in the middle and lower part through a DN80 flange and is connected to the common liquid pipeline 11 flange. Its vent is located in the center of the top end cap through a DN100 flange and is led out through a vent pipe. Its drain is located in the center of the bottom end cap through a flange and is connected to the sewage tank 5 through the liquid pipeline 11. A DN50 spring-loaded full-lift safety valve is also installed on the top end cap of the shell through a flange.
[0084] In one possible implementation, the vent pipe is connected to the safety valve outlet at the top of the horizontal separator 1, the vertical separator 2, and the flash tank 4, respectively.
[0085] In one embodiment, the vent pipe is made of 20# steel, with a design pressure of 6.3MPa. The main pipe is DN150, and the outlet branch pipes of each safety valve are DN50. They are connected to the main pipe through a tee and then led to the flare or the atmosphere.
[0086] In one possible implementation, a bypass gas pipeline 10 is provided in parallel between the gas pipelines 10 of the horizontal separator 1 and the vertical separator 2. The bypass gas pipeline 10 is equipped with a gate valve 9 to realize the series connection or bypass isolation between the horizontal separator 1 and the vertical separator 2.
[0087] In one embodiment, a bypass gas pipeline 10 is provided on the gas pipeline 10 between the horizontal separator 1 and the vertical separator 2, and a gate valve 9 is installed on the bypass pipeline to form a bridging connection; when either separator is under maintenance, its inlet and outlet gate valves 9 are closed and the bypass gate valve 9 is opened, and natural gas directly enters the compressor 3 through the second filter 7, so as to achieve maintenance without stopping the machine.
[0088] In one possible implementation, the bottom of the horizontal separator 1 is a conical structure, and a liquid outlet is provided at the lowest point of the conical bottom. The liquid outlet is connected to the sand box 6 through a liquid pipe 11.
[0089] In one embodiment, the horizontal separator 1, the vertical separator 2, the flash tank 4, and the sewage tank 5 are all fixed to the concrete foundation by ear-type supports; the gas pipeline 10, the liquid pipeline 11, and the venting pipeline are laid using low supports or pipe racks, and thermal compensation is achieved using π-type bends or corrugated compensators.
[0090] It can be seen that the high-efficiency natural gas separation device provided in this application has the following technical advantages:
[0091] High-efficiency gas separation: Through the synergistic effect of horizontal and vertical separators and the structural optimization of each internal device, it is possible to achieve high-efficiency separation of various impurities in natural gas, especially the separation effect of tiny droplets, foam and fine particulate impurities, which improves the quality and purity of natural gas, effectively removes sand, reduces the impact on downstream equipment, and achieves a solid particle removal rate of ≥99.5% for droplets ≥10μm, enabling switching between continuous and maintenance operation modes.
[0092] Reduced management costs: Through two-stage separation, the liquid and solid particle content in natural gas meets the requirements for normal operation of the compressor, reducing frequent high liquid level shutdowns of the compressor, facilitating the production and operation of the gas gathering station, and reducing a significant amount of maintenance costs.
[0093] Environmental protection and energy saving: The flash tank effectively separates and recycles liquid hydrocarbons, improving resource utilization; the wastewater tank centrally treats and discharges wastewater, meeting environmental protection requirements and achieving the goal of energy conservation and emission reduction.
[0094] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0095] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A high-efficiency natural gas separation device, characterized in that, Includes horizontal separators, vertical separators, compressors, flash tanks, wastewater tanks, sandboxes, gas pipelines, liquid pipelines, and venting pipelines: The gas outlet of the horizontal separator is connected to the gas inlet of the vertical separator via a gas pipeline; The gas outlet of the vertical separator is connected to the air inlet of the compressor via a gas pipeline; The bottom liquid outlet of the horizontal separator is connected to the sand box via a liquid pipe; The bottom liquid outlet of the vertical separator merges with the bottom liquid outlet of the horizontal separator, and is then connected to the liquid inlet of the flash tank via a liquid pipeline. The top gas outlet of the flash tank is connected to a vent pipe, and the bottom liquid outlet of the flash tank is connected to the inlet of the wastewater tank through a liquid pipe. The top of the horizontal separator, vertical separator, and flash tank are all equipped with safety valves, and the outlets of the safety valves are all connected to vent pipes.
2. The high-efficiency natural gas separation device as described in claim 1, characterized in that, The horizontal separator is a primary pre-separator; Inside the horizontal separator, along the airflow direction, an air inlet distribution pipe, a momentum absorber, a flow stabilizer, and a first end interception device are arranged sequentially. The air inlet distribution pipe is connected to the gas inlet of the horizontal separator, and the first end interception device is connected to the gas outlet of the horizontal separator.
3. The high-efficiency natural gas separation device as described in claim 1, characterized in that, The vertical separator is a two-stage fine separator; Inside the vertical separator, along the airflow direction, a gas channel, a defoaming element, a tubular filter element, and a second end interception device are arranged sequentially. The gas channel is connected to the gas inlet of the vertical separator, and the second end interception device is connected to the gas outlet of the vertical separator.
4. The high-efficiency natural gas separation device as described in claim 1, characterized in that, The compressor is equipped with a first filter at its air inlet. The first filter is a mesh cone filter. The inlet of the first filter is connected to the gas outlet of the vertical separator through a gas pipeline. The compressor's air outlet is connected to a flow meter and a gate valve in sequence through a gas pipeline.
5. The high-efficiency natural gas separation device as described in claim 1, characterized in that, A manual gate valve is installed on the liquid pipeline between the bottom liquid outlet of the horizontal separator and the sand box.
6. The high-efficiency natural gas separation device as described in claim 1, characterized in that, The common liquid pipeline where the bottom liquid outlets of the horizontal separator and the vertical separator merge is equipped with a second filter and a check valve. The check valve is located downstream of the second filter, and the outlet end of the common liquid pipeline is connected to the inlet of the flash tank.
7. The high-efficiency natural gas separation device as described in claim 1, characterized in that, The top gas outlet of the flash tank is connected to the flare system or the atmosphere through a vent pipe, and the bottom liquid outlet of the flash tank is connected to the top liquid inlet of the wastewater tank through a liquid pipe.
8. The high-efficiency natural gas separation device as described in claim 1, characterized in that, The vent pipes are connected to the safety valve outlets at the top of the horizontal separator, the vertical separator, and the flash tank, respectively.
9. The high-efficiency natural gas separation device as described in claim 1, characterized in that, A bypass gas pipeline is connected in parallel between the gas pipelines of the horizontal separator and the vertical separator. The bypass gas pipeline is equipped with a gate valve to realize the series connection or bypass isolation between the horizontal separator and the vertical separator.
10. The high-efficiency natural gas separation device as described in claim 1, characterized in that, The bottom of the horizontal separator is a conical structure, and a liquid outlet is provided at the lowest point of the cone bottom. The liquid outlet is connected to the sand box through a liquid pipe.