Liquefied natural gas pretreatment device

Abstract

The invention relates to the technical field of liquefied natural gas pretreatment, and discloses a liquefied natural gas pretreatment device which comprises a gravity settling tank and further comprises a feeding pipe arranged at the top of the gravity settling tank and used for introducing liquefied natural gas into the gravity settling tank; the blow-off pipe is arranged at the lower right corner of the gravity settling tank and is used for discharging impurities settled in the gravity settling tank; the discharging pipe is arranged on the back surface of the gravity settling tank and is used for discharging the liquefied natural gas after the impurities are settled; the lead screw is driven by the motor to rotate, so that the first disc, the first telescopic rod and other components are linked, the first scraping plate and the bristles move downwards while rotating, and impurities on the inner wall of the tank body can be removed. When the arc-shaped pipe descends to the conical surface of the tank bottom, the arc-shaped pipe gets close to the screw rod under the extrusion action of the conical surface, and the first scraping plate keeps being attached to the conical surface, so that impurities adhered to the inner wall of the conical surface of the tank bottom are effectively cleaned, and the problem that the conical inner wall is difficult to touch in a traditional cleaning mode is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of liquefied natural gas pretreatment, and in particular to a liquefied natural gas pretreatment device. Background Art

[0002] Natural gas is stored in underground porous rock formations, including oilfield gas, gasfield gas, coalbed methane, mud volcano gas and biogenic gas, and a small amount is also found in coal seams. It is a high-quality fuel and chemical raw material. The main use of natural gas is as fuel. It can be used to produce carbon black, chemicals and liquefied petroleum gas. In the field of liquefied natural gas (LNG) pretreatment, gravity settling tanks are the core separation equipment, responsible for removing solid impurities, free water and heavy hydrocarbons.

[0003] According to the Chinese patent with the announcement number "CN218130148U", the gravity sedimentation tank disclosed includes a sedimentation tank body, a feed pipe is provided on one side of the sedimentation tank body, a discharge pipe is provided at the bottom end of the sedimentation tank body, an electric valve is provided on the discharge pipe, a slot is provided at the top of the sedimentation tank body, a top cover is provided on the slot, a splicing mechanism is provided between the top cover and the sedimentation tank body, the splicing mechanism includes a docking box and a positioning column, the splicing mechanism is provided with two and symmetrically arranged, an installation box is provided at the top of the top cover, a docking groove is provided at the bottom end of the installation box, a cleaning box is provided on the docking groove, the output end of the second electric telescopic rod is connected to the cleaning box, a cleaning mechanism and a cleaning mechanism are provided on the cleaning box, the cleaning mechanism includes an arc tube, a nozzle and a fixed tube, which is convenient for removing the cleaning mechanism and cleaning the cleaning mechanism, and the operation is simple.

[0004] The above patent uses a vertically movable cleaning brush to clean the vertical inner wall of the tank body during use. However, the bottom of the inner wall of the gravity sedimentation tank is usually conical, and the cleaning brush that can only move vertically is difficult to reach the conical inner wall, which causes impurities to adhere for a long time and affects the separation efficiency. Therefore, a liquefied natural gas pretreatment device is proposed to solve the above-mentioned problem. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a liquefied natural gas pretreatment device in view of the above-mentioned deficiencies in the prior art.

[0006] To solve the above technical problems, the present invention adopts a technical solution: a liquefied natural gas pretreatment device, including a gravity settling tank, and further comprising: A feed pipe is provided at the top of the gravity settling tank and is used to pass liquefied natural gas into the gravity settling tank; The sewage pipe is set at the lower right corner of the gravity sedimentation tank and is used to discharge the impurities precipitated in the gravity sedimentation tank; The discharge pipe is located at the back of the gravity settling tank and is used to discharge the liquefied natural gas after the impurities are precipitated; A cleaning mechanism is provided on the inner wall of the gravity settling tank and is used to clean impurities adhering to the inner wall of the gravity settling tank; The cleaning mechanism includes a screw, a first disc, four first telescopic rods, four fixed blocks, eight arc tubes, a first scraper, four arc rods, and bristles; The bottom end of the screw rod is rotatably connected to the bottom inner wall of the gravity sedimentation tank through a bearing, and extends downward to the outside of the gravity sedimentation tank. The motor is connected to the bottom of the gravity sedimentation tank, and the top output end of the motor is connected to the bottom end of the screw rod through a coupling. The first disc is connected to the top of the screw rod, and the top end of the first telescopic rod is connected to the first disc. The fixed block is connected to the bottom end of the first telescopic rod. The arc tube is hinged on both sides of the fixed block. The first scraper is connected to the arc tube. The first scraper contacts the inner wall of the gravity sedimentation tank. The two ends of the arc rod are sleeved inside the arc tube. Brushes are connected to the arc rod. Impurities adhered to the inner wall of the gravity sedimentation tank are cleaned by the first scraper and the bristles. The bristles contact the inner wall of the gravity sedimentation tank.

[0007] Preferably, the middle part of the screw rod is threadedly connected to a threaded sleeve, an annular groove is provided on the outside of the threaded sleeve, and four spherical sliders are slidably connected inside the annular groove. The four spherical sliders are respectively connected to four fixed blocks through connecting rods.

[0008] Preferably, a vibration mechanism is provided on the arc rod, and the vibration mechanism includes a second telescopic rod, one end of the second telescopic rod is connected to the arc rod, and the other end of the second telescopic rod away from the arc rod is connected to the arc plate, and a spring is provided on the outside of the second telescopic rod, and the two ends of the spring are respectively connected to the arc rod and the arc plate, and the arc plate is driven to rebound by setting the spring.

[0009] Preferably, a wave slide rail is connected to the side of the arc tube close to the screw rod, and spherical top blocks are connected to both ends of the arc plate. The spherical top blocks are in contact with the wave slide rail. During the process of the arc rod shrinking into the inside of the arc tube, the spherical top blocks will repeatedly move toward the inner wall of the gravity sedimentation tank under the action of the wave slide rail and the spring.

[0010] Preferably, the arc-shaped plate is connected to a fixed plate, two rubber rods are connected to the fixed plate, and the other end of the rubber rod away from the fixed plate is connected to a percussion hammer, and the percussion hammer contacts the inner wall of the gravity sedimentation tank. The vibration generated when the percussion hammer contacts the inner wall of the gravity sedimentation tank will shake off the impurities attached to the inner wall of the gravity sedimentation tank.

[0011] Preferably, a dredging mechanism is provided inside the feed pipe, and the dredging mechanism includes a filter screen. The filter screen is provided on the inner wall of the feed pipe, and the liquefied natural gas entering the gravity settling tank is preliminarily filtered through the filter screen.

[0012] Preferably, an impeller is connected to the top of the first disc, and the centrifugal force generated by the impeller causes the fluid to be evenly diffused into the interior of the gravity sedimentation tank, reducing the impact of fluid disturbance on gravity sedimentation. The top of the impeller is connected to a vertical rod, and the top of the vertical rod is connected to a cam. One end of the cam is connected to a second scraper, and the impurities attached to the inner wall of the feed pipe are scraped off by the second scraper.

[0013] Preferably, the filter screen is slidably connected to a slide rod through a linear bearing, the bottom end of the slide rod is connected to a second disc, the top of the second disc is connected to a thimble, the thimble contacts the filter holes on the filter screen, and the impurities blocked in the filter holes of the filter screen are cleared by the thimble, and the upper right corner of the cam is hinged to the lower right corner of the second disc through an inclined rod.

[0014] The present invention adopts the above technical solution, which can bring the following beneficial effects: 1. This invention incorporates a cleaning mechanism that uses a motor to drive a screw, which in turn activates the first disc, first telescopic rod, and other components. The first scraper and bristles rotate and move downward simultaneously, removing impurities from the inner wall of the tank. When the curved tube descends to the conical surface of the tank bottom, it is squeezed toward the screw by the conical surface, and the first scraper maintains contact with the conical surface, effectively cleaning impurities adhering to the inner wall of the tank bottom. This solves the problem of traditional cleaning methods being difficult to reach the conical inner wall.

[0015] 2. This invention drives the threaded sleeve to move downward along the axis when the screw rotates. The spherical slider cooperates with the annular groove to make the fixed block slowly descend while rotating, forming a spiral cleaning trajectory, extending the action time of the cleaning mechanism on the conical surface, ensuring that each area is repeatedly cleaned, and combined with the reasonable setting of the motor speed and the threaded sleeve descending speed, significantly improving the comprehensiveness and efficiency of cleaning.

[0016] 3. This invention incorporates a vibration mechanism. As the curved rod retracts into the curved tube, the spherical top block, driven by a wave-shaped slide and spring, drives the hammer to repeatedly strike the tank wall, generating vibrations that shake impurities off. Simultaneously, the rubber rod bends when the hammer contacts the tank wall. The rebound force causes the hammers to collide with each other, generating a different vibration frequency. This dual-frequency vibration covers the resonant frequencies of different impurities, effectively improving the cleaning efficiency of stubborn impurities such as ice hydrates and heavy hydrocarbon colloids.

[0017] 4. This invention incorporates a dredging mechanism, which allows the filter screen to initially filter LNG entering the gravity settling tank. The impeller rotates with the first disc, generating centrifugal force to evenly disperse the fluid and reduce disturbance. Simultaneously, a cam drives a second scraper to remove impurities from the inner wall of the feed pipe. A tilted rod also drives the ejector pin up and down to unclog the filter screen. This achieves both cleaning the inner wall of the feed pipe and unclogging the filter screen. This, in conjunction with the cleaning mechanism, enhances the overall performance of the pretreatment device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the gravity settling tank area in the present invention; Figure 3 Schematic diagram of the screw rod area structure in the present invention; Figure 4 This is an exploded view of the annular rod area in the present invention; Figure 5 For the present invention Figure 4 Enlarged view of point A in the middle; Figure 6 For the present invention Figure 4 Enlarged view of point B in the middle; Figure 7 This is a schematic diagram of the structure of the hammer area in the present invention; Figure 8 Schematic diagram of the internal structure of the feed pipe area in the present invention; Figure 9 This is an exploded view of the cam area in the present invention.

[0019] Figure: 1. Gravity settling tank; 2. Feed pipe; 3. Drain pipe; 4. Motor; 5. Cleaning mechanism; 501. Screw; 502. First disc; 503. First telescopic rod; 504. Fixed block; 505. Curved tube; 506. First scraper; 507. Curved rod; 508. Brush; 509. Threaded sleeve; 5010. Annular chute; 5011. Spherical slider; 5012. Connecting rod; 6. Vibrator Structure; 601, second telescopic rod; 602, spring; 603, arc plate; 604, wave slide; 605, spherical top block; 606, fixed plate; 607, rubber rod; 608, knock hammer; 7, dredging mechanism; 701, filter screen; 702, impeller; 703, vertical rod; 704, cam; 705, second scraper; 706, slide rod; 707, second disc; 708, ejector pin; 709, oblique rod. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] See also Figure 1-9 One embodiment of the present invention is: a liquefied natural gas pretreatment device, including a gravity settling tank 1, and further comprising: A feed pipe 2 is provided at the top of the gravity settling tank 1 and is used to pass liquefied natural gas into the gravity settling tank 1; The sewage pipe 3 is provided at the lower right corner of the gravity sedimentation tank 1 and is used to discharge the impurities precipitated in the gravity sedimentation tank 1; A discharge pipe is provided on the back of the gravity settling tank 1 and is used to discharge the liquefied natural gas after the impurities are precipitated; The cleaning mechanism 5 is provided on the inner wall of the gravity settling tank 1 and is used to clean the impurities adhering to the inner wall of the gravity settling tank 1; The cleaning mechanism 5 includes a screw 501, a first disc 502, four first telescopic rods 503, four fixed blocks 504, eight arc tubes 505, a first scraper 506, four arc rods 507, and bristles 508; The bottom end of the screw rod 501 is rotatably connected to the bottom inner wall of the gravity sedimentation tank 1 through a bearing and extends downward to the outside of the gravity sedimentation tank 1. The motor 4 is connected to the bottom of the gravity sedimentation tank 1. The top output end of the motor 4 is connected to the bottom end of the screw rod 501 through a coupling. The first disc 502 is connected to the top of the screw rod 501. The top end of the first telescopic rod 503 is connected to the first disc 502. The fixed block 504 is connected to the bottom of the first telescopic rod 503. End, the arc tube 505 is hinged on both sides of the fixed block 504, the first scraper 506 is connected to the arc tube 505, the first scraper 506 is in contact with the inner wall of the gravity sedimentation tank 1, and the two ends of the arc rod 507 are sleeved inside the arc tube 505. The arc rod 507 is connected with bristles 508. The impurities adhered to the inner wall of the gravity sedimentation tank 1 are cleaned by the first scraper 506 and the bristles 508, and the bristles 508 are in contact with the inner wall of the gravity sedimentation tank 1.

[0022] The middle part of the screw rod 501 is threadedly connected to a threaded sleeve 509, and an annular groove 5010 is provided on the outside of the threaded sleeve 509. Four spherical sliders 5011 are slidably connected inside the annular groove 5010. The four spherical sliders 5011 are respectively connected to the four fixed blocks 504 through connecting rods 5012.

[0023] Working principle: First, turn on the motor 4 to drive the screw rod 501 to rotate, the rotation of the screw rod 501 drives the first disc 502 to rotate, the rotation of the first disc 502 drives the first telescopic rod 503 to rotate, the rotation of the first telescopic rod 503 drives the fixed block 504 to rotate, the rotation of the fixed block 504 drives the arc tube 505 to rotate, the rotation of the arc tube 505 drives the arc rod 507 to rotate, the rotation of the arc rod 507 drives the bristles 508 to rotate, and the rotation of the arc tube 505 drives the first scraper 506 to rotate at the same time. During the rotation of the first scraper 506 and the bristles 508, impurities adhered to the inner wall of the gravity sedimentation tank 1 are removed. As the screw rod 501 rotates, it drives the threaded sleeve 509 to move downward. During the downward movement of the threaded sleeve 509, the fixed block 504 is driven to move downward through the spherical slider 5011 and the connecting rod 5012. At the same time, the spherical slider 5011 rotates inside the annular slide groove 5010. During the downward movement of the fixed block 504, it drives the arc tube 505 to move downward. During the downward movement of the arc tube 505, it drives the first scraper 506 and the bristles 508 to move downward. As a result, the first scraper 506 and the bristles 508 will move downward while rotating, thereby improving the cleaning effect of the inner wall of the gravity sedimentation tank 1. When the arc tube 505 descends to the bottom conical surface of the gravity sedimentation tank 1, it will move closer to the screw rod 501 under the extrusion of the bottom conical surface of the gravity sedimentation tank 1. At the same time, the arc rod 507 will shrink to the inside of the arc tube 505 under the action of the extrusion force. Therefore, even when the arc tube 505 and the first scraper 506 descend to the bottom conical surface of the gravity sedimentation tank 1, the first scraper 506 remains in contact with the bottom conical surface of the gravity sedimentation tank 1, thereby cleaning impurities adhered to the inner wall of the bottom conical surface of the gravity sedimentation tank 1.

[0024] See also Figure 1-9 On the basis of the above embodiment, in another embodiment of the present invention, a vibration mechanism 6 is provided on the arc rod 507, and the vibration mechanism 6 includes a second telescopic rod 601, one end of the second telescopic rod 601 is connected to the arc rod 507, and the other end of the second telescopic rod 601 away from the arc rod 507 is connected to the arc plate 603, and a spring 602 is provided on the outside of the second telescopic rod 601, and the two ends of the spring 602 are respectively connected to the arc rod 507 and the arc plate 603, and the spring 602 is provided to drive the arc plate 603 to rebound.

[0025] A wave slide 604 is connected to the side of the arc tube 505 close to the screw rod 501, and spherical top blocks 605 are connected to both ends of the arc plate 603. The spherical top blocks 605 are in contact with the wave slide 604. During the process of the arc rod 507 contracting into the interior of the arc tube 505, the spherical top block 605 will repeatedly move toward the inner wall of the gravity sedimentation tank 1 under the action of the wave slide 604 and the spring 602.

[0026] The curved plate 603 is connected to a fixed plate 606, and two rubber rods 607 are connected to the fixed plate 606. The other end of the rubber rod 607 away from the fixed plate 606 is connected to a striking hammer 608, and the striking hammer 608 contacts the inner wall of the gravity sedimentation tank 1. The vibration generated when the striking hammer 608 contacts the inner wall of the gravity sedimentation tank 1 will shake off the impurities attached to the inner wall of the gravity sedimentation tank 1.

[0027] Working principle: During the process of the arc rod 507 contracting into the interior of the arc tube 505, the spherical top block 605 will repeatedly move toward the inner wall of the gravity sedimentation tank 1 under the action of the wave slide rail 604 and the spring 602, thereby driving the arc plate 603, the fixed plate 606, the rubber rod 607 and the two knocking hammers 608 to move toward the inner wall of the gravity sedimentation tank 1. When the two knocking hammers 608 come into contact with the inner wall of the gravity sedimentation tank 1, vibration is generated, and impurities attached to the inner wall of the gravity sedimentation tank 1 are shaken off by the vibration, thereby removing the impurities attached to the inner wall of the gravity sedimentation tank 1. When the two hammers 608 come into contact with the inner wall of the gravity sedimentation tank 1, the two rubber rods 607 will bend to both sides. When the hammers 608 move in the opposite direction under the rebound force of the spring 602, the two hammers 608 will collide with each other under the rebound force of the two rubber rods 607 and generate another vibration frequency. The vibration of the two frequencies improves the cleaning effect of impurities attached to the inner wall of the gravity sedimentation tank 1.

[0028] See also Figure 1-9 On the basis of the above embodiment, in another embodiment of the present invention, a dredging mechanism 7 is provided inside the feed pipe 2, and the dredging mechanism 7 includes a filter screen 701. The filter screen 701 is provided on the inner wall of the feed pipe 2, and the liquefied natural gas entering the gravity sedimentation tank 1 is preliminarily filtered through the filter screen 701.

[0029] The top of the first disc 502 is connected to an impeller 702. The centrifugal force generated by the impeller 702 causes the fluid to be evenly diffused into the interior of the gravity sedimentation tank 1, reducing the impact of fluid disturbance on gravity sedimentation. The top of the impeller 702 is connected to a vertical rod 703. The top of the vertical rod 703 is connected to a cam 704. One end of the cam 704 is connected to a second scraper 705. The second scraper 705 is used to scrape off impurities attached to the inner wall of the feed pipe 2.

[0030] The filter screen 701 is slidably connected to a slide rod 706 through a linear bearing. The bottom end of the slide rod 706 is connected to a second disc 707. The top of the second disc 707 is connected to a thimble 708. The thimble 708 contacts the filter holes on the filter screen 701. The impurities blocked in the filter holes on the filter screen 701 are cleared by the thimble 708. The upper right corner of the cam 704 and the lower right corner of the second disc 707 are hinged through a diagonal rod 709.

[0031] Working principle: During the rotation of the first disc 502, the impeller 702 is driven to rotate. The centrifugal force generated by the impeller 702 causes the fluid to diffuse evenly into the interior of the gravity sedimentation tank 1, reducing the impact of fluid disturbance on gravity sedimentation. The rotation of the impeller 702 drives the vertical rod 703 to rotate, and the rotation of the vertical rod 703 drives the cam 704 to rotate. The rotation of the cam 704 drives the second scraper 705 to rotate, and the impurities attached to the inner wall of the feed pipe 2 are scraped off by the second scraper 705. During the rotation of the cam 704, the second disc 707 is driven to move up and down through the inclined rod 709. During the up and down movement of the second disc 707, the ejector pin 708 is driven to move up and down. During the up and down movement of the ejector pin 708, it will be inserted into the filter holes on the filter screen 701 to clear the impurities blocked in the filter holes.

[0032] The present invention provides a liquefied natural gas pretreatment device. Numerous methods and approaches exist for implementing this technical solution. The foregoing merely represents a preferred embodiment of the present invention. It should be noted that those skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications are also within the scope of protection of the present invention. Components not specified in this embodiment may be implemented using existing technologies.

Claims

1. A liquefied natural gas pretreatment device, comprising a gravity settling tank, characterized in that: Also includes: A feed pipe is provided at the top of the gravity settling tank and is used to pass liquefied natural gas into the gravity settling tank; The sewage pipe is set at the lower right corner of the gravity sedimentation tank and is used to discharge the impurities precipitated in the gravity sedimentation tank; The discharge pipe is located at the back of the gravity settling tank and is used to discharge the liquefied natural gas after the impurities are precipitated; A cleaning mechanism is provided on the inner wall of the gravity settling tank and is used to clean impurities adhering to the inner wall of the gravity settling tank; The cleaning mechanism includes a screw, a first disc, four first telescopic rods, four fixed blocks, eight arc tubes, a first scraper, four arc rods, and bristles; The bottom end of the screw rod is rotatably connected to the bottom inner wall of the gravity sedimentation tank through a bearing, and extends downward to the outside of the gravity sedimentation tank. The motor is connected to the bottom of the gravity sedimentation tank, and the top output end of the motor is connected to the bottom end of the screw rod through a coupling. The first disc is connected to the top of the screw rod, and the top of the first telescopic rod is connected to the first disc. The fixed block is connected to the bottom end of the first telescopic rod. The arc tube is hinged on both sides of the fixed block. The first scraper is connected to the arc tube, and the first scraper contacts the inner wall of the gravity sedimentation tank. The two ends of the arc rod are sleeved inside the arc tube. Brushes are connected to the arc rod, and the bristles contact the inner wall of the gravity sedimentation tank.

2. A liquefied natural gas pretreatment device according to claim 1, characterized in that: The middle part of the screw rod is threadedly connected with a threaded sleeve, the outside of the threaded sleeve is provided with an annular sliding groove, the inside of the annular sliding groove is slidably connected with four spherical sliders, and the four spherical sliders are respectively connected to four fixed blocks through connecting rods.

3. A liquefied natural gas pretreatment device according to claim 2, characterized in that: A vibration mechanism is provided on the arc-shaped rod, and the vibration mechanism includes a second telescopic rod, one end of the second telescopic rod is connected to the arc-shaped rod, and the other end of the second telescopic rod away from the arc-shaped rod is connected to the arc-shaped plate. A spring is provided on the outside of the second telescopic rod, and the two ends of the spring are respectively connected to the arc-shaped rod and the arc-shaped plate.

4. A liquefied natural gas pretreatment device according to claim 3, characterized in that: The side of the arc tube close to the screw rod is connected with a wave slide rail, and the two ends of the arc plate are connected with spherical top blocks, and the spherical top blocks are in contact with the wave slide rail.

5. The liquefied natural gas pretreatment device according to claim 4, characterized in that: The arc-shaped plate is connected to a fixing plate, the fixing plate is connected to two rubber rods, the other end of the rubber rod away from the fixing plate is connected to a knock hammer, and the knock hammer is in contact with the inner wall of the gravity sedimentation tank.

6. The liquefied natural gas pretreatment device according to claim 5, characterized in that: A dredging mechanism is provided inside the feed pipe, and the dredging mechanism includes a filter screen, and the filter screen is provided on the inner wall of the feed pipe.

7. The liquefied natural gas pretreatment device according to claim 6, characterized in that: The top of the first disc is connected to an impeller, the top of the impeller is connected to a vertical rod, the top of the vertical rod is connected to a cam, and one end of the cam is connected to a second scraper.

8. The liquefied natural gas pretreatment device according to claim 7, characterized in that: The filter screen is slidably connected to a sliding rod through a linear bearing, the bottom end of the sliding rod is connected to a second disc, the top of the second disc is connected to a thimble, the thimble contacts the filter holes on the filter screen, and the upper right corner of the cam is hinged to the lower right corner of the second disc through an inclined rod.

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