A cryogenic separation and liquefaction device for liquefied natural gas production

Abstract

This invention discloses a cryogenic separation and liquefaction device for liquefied natural gas (LNG) production, relating to the field of natural gas technology. It includes a working frame with a frame cover at its top and a conveying pipe at the top of the cover. The device includes a lifting mechanism, a receiving mechanism, and a processing mechanism. The processing mechanism includes processing bucket frames, with several processing bucket frames equidistantly arranged within the working frame cavity. Each processing bucket frame is fitted with a sealing cover, and obstructing inclined plates are installed on both sides of the inner cavity of each processing bucket frame. This invention utilizes multiple funnel-shaped processing bucket frames connected end-to-end, allowing the raw gas to flow sequentially from bottom to top. The natural gas flow channel is longitudinally elongated, forming staggered obstructing inclined plates and equidistantly arranged obstructing arc plates that continuously disturb the airflow, constantly changing the gas flow direction to create turbulence. This significantly extends the residence time of natural gas in the cryogenic cavity, ensuring sufficient heat exchange between the gas and the cryogenic cavity, and efficiently condensing and liquefying heavy components, thus significantly improving the liquefaction yield and the separation accuracy of light and heavy components.

Description

Technical Field

[0001] This invention relates to the field of natural gas technology, specifically to a cryogenic separation and liquefaction device for liquefied natural gas production. Background Technology

[0002] Currently, traditional cryogenic separation chambers are mostly straight-through flow channels without turbulence or obstruction structures. After the raw material natural gas is introduced into the chamber, it flows out directly and quickly. The gas has a short contact time with the cryogenic chamber wall for heat exchange, resulting in incomplete condensation and liquefaction of heavy components of natural gas and incomplete separation of light and heavy components. In addition, the liquefaction yield is low. The liquid LNG generated by condensation adheres to the surface of the chamber baffle and cannot be quickly collected. Over time, the accumulation of scale blocks the airflow channel, further deteriorating the separation effect. Conventional heat exchange pipelines are mostly single-point direct-insertion pipes, with the heat exchange medium only partially contacting the cavity. The temperature difference is large in the circumference and vertical direction of the inner cavity of the processing bucket frame, and the local temperature cannot reach the low temperature conditions required for liquefaction. The liquefaction conditions fluctuate greatly. In most equipment, the heat exchange medium is directly discarded after a single introduction, without a closed-loop recovery pipeline. The consumption of refrigerant / heat exchange medium is high and the production energy consumption is large. The arrangement of raw gas lines and heat exchange medium pipelines is messy, which can easily lead to pipeline cross-contamination. The mixing of heat exchange medium with natural gas affects the purity of the finished LNG. Traditional equipment top covers are locked with all flange bolts. Disassembly and assembly require disassembling each fastener individually. Multi-level internal component maintenance and cavity unblocking are time-consuming and labor-intensive. Manual lifting and opening of the cover is not guided or limited. The top cover is prone to deviation and swaying during lifting and lowering, and it is difficult to fall back into position. This can easily lead to misalignment of the seal, air leakage, and cold air leakage. After separation and liquefaction, the liquid LNG is scattered in the bottom cavity of the equipment. There is no dedicated collection cavity, making manual collection difficult. The storage tank has no reinforced structure and is prone to bulging and deformation under the static pressure of low-temperature liquid and the impact of the medium. Summary of the Invention

[0003] The purpose of this invention is to provide a cryogenic separation and liquefaction device for liquefied natural gas production, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a cryogenic separation and liquefaction device for liquefied natural gas production, comprising a working frame, a frame cover installed at the top of the working frame, and a conveying pipe installed at the top of the frame cover, comprising a lifting mechanism, a receiving mechanism and a processing mechanism; The processing mechanism includes a processing bucket frame, and a plurality of processing bucket frames are equidistantly arranged in the inner cavity of the working frame. Each processing bucket frame is equipped with a sealing cover. Both sides of the inner cavity of the processing bucket frame are equipped with obstructing inclined plates, and the obstructing inclined plates on both sides are distributed in a staggered structure. The bottom of the inner cavity of the processing bucket frame at the top and middle is equipped with obstructing plates with a staggered structure.

[0005] Preferably, the bottom sealing cap is connected to the bottom of the middle processing bucket frame, and the top of the middle sealing cap is connected to the bottom of the top processing bucket frame. Both the processing bucket frame and the sealing cap have a funnel-shaped structure.

[0006] Preferably, a working valve pipe for connecting to an external conveying mechanism is installed at the bottom left side of the working frame, and the right end of the working valve pipe passes through the working frame and connects to one side of the bottom of the processing bucket frame. Conveying air holes are opened around the inner cavity of the processing bucket frame, and the conveying air holes have a spiral structure.

[0007] Preferably, a connecting pipe is installed at the bottom right side of the processing bucket frame relative to the air conveying hole. A connecting cavity is opened on the right side of the inner cavity of the working frame. A connecting valve pipe for connecting to an external heat exchange mechanism is installed at the bottom right side of the working frame corresponding to the connecting cavity. The end of the connecting pipe away from the processing bucket frame is connected to one side of the inner cavity of the working frame. A connecting hole is opened on one side of the inner cavity of the connecting cavity at the corresponding position of the connecting pipe.

[0008] Preferably, a connecting slot is provided on the left side of the inner cavity of the working frame, a discharge valve pipe is installed on the upper left side of the processing bucket frame, a discharge hole is provided on the right side of the connecting slot at the corresponding position of the discharge valve pipe, a discharge pipe connected to an external heat exchange mechanism is installed on the left side of the working frame at the corresponding position of the connecting slot, a discharge round opening is provided in the inner cavity of the connecting slot at the corresponding position of the discharge pipe, and a connection port is provided on the upper left side of the processing bucket frame between the corresponding positions of the discharge valve pipe and the conveying air hole.

[0009] Preferably, a spiral air pipe is installed at the top of the sealing cover, and the top of the spiral air pipe is connected to the bottom of the conveying pipe. Several blocking arc plates are installed at equal intervals at the top and bottom of the opposing sides of the blocking inclined plates. A discharge slot is opened on the side of the inner cavity of the blocking inclined plate away from the working frame. A collection slot is opened at the top of the inner cavity of the discharge slot at the corresponding position of the blocking arc plate.

[0010] Preferably, a collection tank is installed at the bottom of the inner cavity of the working frame, and several partition plates are installed at equal intervals at the bottom of the inner cavity of the collection tank. A liquid level sensor is installed at the upper left side of the inner cavity of the collection tank. The liquid level sensor is electrically connected to an external control center. A placement recess is provided at the bottom of the inner cavity of the working frame.

[0011] Preferably, mounting frames are installed on the upper ends of both sides of the working frame, connecting plates are installed on both sides of the frame cover, multiple electric push rods are installed in the inner cavity of the mounting frame, the top ends of the multiple electric push rods are connected to the bottom ends of the connecting plates, a stabilizing groove is opened on one side of the top of the mounting frame, a stabilizing slide plate is slidably installed in the inner cavity of the stabilizing groove, and the top end of the stabilizing slide plate is connected to the bottom end of the connecting plate.

[0012] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention uses multiple sets of funnel-shaped processing frames connected end to end, with the raw gas flowing through from bottom to top in stages. The natural gas flow channel is longitudinally elongated, forming staggered obstruction plates and equally spaced obstruction arc plates that continuously disturb the airflow, constantly changing the gas flow direction to form turbulence. This significantly extends the residence time of natural gas in the low-temperature chamber, allowing the gas to fully contact and exchange heat with the low-temperature chamber. Heavy components are efficiently condensed and liquefied, significantly improving the liquefaction yield and the separation accuracy of light and heavy components. The funnel-shaped structure relies on gravity for self-flow, and the liquid condensed in each stage of the chamber flows naturally downward along the inclined surface of the processing frame, eliminating the need for additional liquid transfer pumps and reducing the investment in supporting power equipment and operating energy consumption. 2. This invention allows liquid material condensed on the surfaces of the obstructing inclined plates and obstructing arc plates to flow into the discharge trough through the collection holes and then fall into the bucket frame. This avoids long-term liquid adhesion to the components, causing scaling and blockage, and ensures smooth airflow and stable heat exchange efficiency in the cavity. The heat exchange medium flows around the cavity through the spirally arranged conveying air holes along the side wall of the bucket frame, maximizing the contact area between the heat exchange medium and the inner wall of the cavity. This achieves uniform and controllable temperature throughout the entire cavity of the treatment bucket frame, eliminating the problem of unstable liquefaction conditions caused by excessive local temperature differences, forming a closed-loop circulation circuit. After the heat exchange medium has completed heat exchange, it is fully recovered and reused, significantly reducing heat exchange medium loss and lowering the energy consumption of the device during continuous production. The right-side pipeline runs through the heat exchange liquid inlet, the left-side pipeline runs through the heat exchange liquid return, and the top spiral gas pipe connects to the raw material gas inlet conveying pipe. The raw material natural gas channel and the heat exchange medium channel are physically isolated, structurally preventing the heat exchange medium from mixing with the raw material gas and ensuring the purity of the finished liquefied natural gas. 3. This invention strengthens the overall structural rigidity of the collection tank through the partition plate, improving the tank's resistance to liquid static pressure and low-temperature impact, preventing the storage tank from deforming under pressure, extending the tank's service life. The top of the partition plate does not contact the tank top, does not obstruct the gravity flow and collection of liquid substances, does not occupy the effective storage volume, and monitors the liquid level in the tank in real time. When the liquid level reaches the set threshold, it automatically sends an early warning signal to the central control, reminding the staff to unload the material in time, replacing manual fixed-point inspections, preventing liquid overflow and leakage, and improving the safety production factor of the device. Attached Figure Description

[0013] Figure 1 A schematic diagram of the overall structure is provided for embodiments of the present invention; Figure 2 This is a cross-sectional structural diagram of the working frame provided in an embodiment of the present invention; Figure 3 This is a cross-sectional structural diagram of the blocking inclined plate provided in an embodiment of the present invention; Figure 4 This is a cross-sectional structural diagram of the collection tank provided in an embodiment of the present invention; Figure 5 This is a cross-sectional view of one side of the mounting frame provided in an embodiment of the present invention.

[0014] In the diagram: 1. Working frame; 2. Lifting mechanism; 201. Mounting frame; 202. Connecting plate; 203. Multi-section electric push rod; 204. Stabilizing slide; 205. Stabilizing slide plate; 3. Receiving mechanism; 301. Collection tank; 302. Divider plate; 303. Liquid level sensor; 4. Processing mechanism; 401. Working valve pipe; 402. Discharge pipe; 403. Connecting trough; 404. Processing bucket frame; 405. Connecting pipe; 406. Connecting valve pipe; 407. Connecting cavity; 408. Conveying air hole; 409. Sealing cover; 410. Baffle plate; 411. Baffle arc plate; 412. Spiral air pipe; 413. Discharge trough; 414. Collection hole trough; 5. Frame cover; 6. Conveying pipe. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Please see Figure 1-5 The present invention provides a technical solution: a cryogenic separation and liquefaction device for liquefied natural gas production, including a working frame 1, and a frame cover 5 installed at the top of the working frame 1, and a conveying pipe 6 installed at the top of the frame cover 5, including a lifting mechanism 2, a receiving mechanism 3 and a processing mechanism 4. The processing mechanism 4 includes a processing bucket frame 404, and a plurality of processing bucket frames 404 are equidistantly arranged in the inner cavity of the working frame 1. Each processing bucket frame 404 is equipped with a sealing cover 409. Both sides of the inner cavity of the processing bucket frame 404 are equipped with blocking inclined plates 410, and the blocking inclined plates 410 on both sides are distributed in a staggered structure. The bottom of the inner cavity of the processing bucket frame 404 at the top and middle are equipped with blocking plates with a staggered structure.

[0017] Furthermore, the bottom sealing cap 409 is connected to the bottom of the middle processing bucket frame 404, and the top of the middle sealing cap 409 is connected to the bottom of the top processing bucket frame 404. Both the processing bucket frame 404 and the sealing cap 409 have a funnel-shaped structure. The bottom left side of the working frame 1 is equipped with a working valve pipe 401 that connects to an external conveying mechanism. The right side of the working valve pipe 401 passes through the working frame 1 and connects to one side of the bottom of the processing bucket frame 404. The processing bucket frame 404 has conveying air holes 408 around its inner cavity, and the conveying air holes 408 have a spiral structure. A connecting pipe 405 is installed at the bottom right side of the processing bucket frame 404, opposite to the conveying air hole 408. A connecting cavity 407 is opened on the right side of the inner cavity of the working frame 1. A connecting valve pipe 406 connected to an external heat exchange mechanism is installed at the bottom right side of the working frame 1, corresponding to the connecting cavity 407. The end of the connecting pipe 405 away from the processing bucket frame 404 is connected to one side of the inner cavity of the working frame 1. A connecting hole is opened on one side of the inner cavity of the connecting cavity 407, corresponding to the connecting pipe 405. A connecting slot 403 is provided on the left side of the inner cavity of the working frame 1. A discharge valve pipe is installed on the upper left side of each processing bucket frame 404. A discharge hole is provided on the right side of the connecting slot 403 at the corresponding position of the discharge valve pipe. A discharge pipe 402 connected to an external heat exchange mechanism is installed on the left side of the working frame 1 at the corresponding position of the connecting slot 403. A discharge round opening is provided in the inner cavity of the connecting slot 403 at the corresponding position of the discharge pipe 402. A connection port is provided on the upper left side of the processing bucket frame 404 between the corresponding positions of the discharge valve pipe and the conveying air hole 408. The top of the sealing cover 409 is equipped with a spiral air pipe 412. The top of the spiral air pipe 412 is connected to the bottom of the conveying pipe 6. Several blocking arc plates 411 are installed at equal intervals on the top and bottom of the opposing side of the blocking inclined plates 410. The side of the inner cavity of the blocking inclined plate 410 away from the working frame 1 is provided with a discharge slot 413. The top of the inner cavity of the discharge slot 413 is provided with a collection hole slot 414 at the corresponding position of the blocking arc plate 411. The specific implementation method is as follows: When the gas is liquefied by low-temperature separation, the gas is supplied to the inner cavity of the bottom processing bucket frame 404 through the working valve pipe 401. Since several processing bucket frames 404 are interconnected, when the gas flows from bottom to top, when the gas flow reaches the inner cavity of the corresponding processing bucket frame 404, the external heat exchange mechanism is activated to supply the heat exchange material to the inside of the connecting pipe 405 through the connecting valve pipe 406. The material is then supplied to the inside of the conveying air hole 408 through the connecting pipe 405. When the heat exchanged material flows in the inner cavity of the conveying air hole 408, the temperature of the inner cavity of the processing bucket frame 404 is regulated. Finally, the heat-exchanged material is supplied to the inside of the connecting empty tank 403 through the discharge valve pipe. The discharge pipe 402 is recycled to the external heat exchange mechanism, and the temperature inside the processing bucket frame 404 is regulated by sequential circulation. The staggered baffle plate 410 inside the processing bucket frame 404 and the baffle arc plates 411 installed at the top and bottom of the baffle plate 410 increase the retention capacity of the airflow when flowing inside the processing bucket frame 404, so that the airflow can be fully processed in the processing bucket frame 404. When liquid is generated during the processing, the liquid will accumulate at the top of the baffle plate 410. The liquid is collected through the collection slot 414 and the discharge slot 413. Finally, the liquid is collected through the funnel-shaped processing bucket frame 404 and discharged into the collection tank 301.

[0018] A collection tank 301 is installed at the bottom of the inner cavity of the working frame 1. Several partition plates 302 are installed at equal intervals at the bottom of the inner cavity of the collection tank 301. A liquid level sensor 303 is installed at the upper left side of the inner cavity of the collection tank 301. The liquid level sensor 303 is electrically connected to the external control center. A placement notch is opened at the bottom of the inner cavity of the working frame 1. The specific implementation method is as follows: When the gas is converted into liquid during the low-temperature separation process, it is collected centrally through the collection tank 301. During the collection process, when the liquid collected in the collection tank 301 reaches the pre-set capacity, the liquid level sensor 303 is triggered, and the external control center is triggered to notify the staff that the collected liquid needs to be processed. The partition plate 302 in the inner cavity of the collection tank 301 improves the stability and firmness of the collection tank 301 during use. Since the top of the partition plate 302 is not connected to the top of the collection tank 301, it will not affect the normal collection operation of the collection tank 301.

[0019] The upper ends of both sides of the working frame 1 are equipped with mounting frames 201, and the upper ends of both sides of the frame cover 5 are equipped with connecting plates 202. The inner cavity of the mounting frame 201 is equipped with multiple electric push rods 203. The top ends of the multiple electric push rods 203 are connected to the bottom ends of the connecting plates 202. A stabilizing groove 204 is provided on one side of the top end of the mounting frame 201. A stabilizing slide plate 205 is slidably installed in the inner cavity of the stabilizing groove 204. The top end of the stabilizing slide plate 205 is connected to the bottom end of the connecting plate 202. The specific implementation method is as follows: During the process of processing the inner cavity of the working frame 1, the multi-section electric push rods 203 on both sides are activated. The extension ends of the multi-section electric push rods 203 move upward, and drive the connecting plate 202 to move upward. The connecting plate 202 drives the frame cover 5 to move upward, so that the bottom end of the frame cover 5 is separated from the top end of the working frame 1, which improves the convenience of processing the inner cavity of the working frame 1. When the connecting plate 202 moves upward, it drives the stabilizing slide plate 205 to slide inside the stabilizing slide groove 204. Through the cooperation of the stabilizing slide plate 205 and the stabilizing slide groove 204, the stability of the connecting plate 202 and the frame cover 5 during movement is increased. The frame cover 5 can be quickly lifted by the multi-section electric push rod 203, so that the top of the working frame 1 is in an open state, which facilitates the disassembly and maintenance of the multi-stage processing bucket frame 404 inside the working frame 1 and the cleaning and unclogging of the cavity. This greatly reduces the downtime for equipment maintenance and increases the equipment uptime. When the connecting plate 202 is raised and lowered, the stabilizing slide plate 205 slides directionally along the stabilizing slide groove 204, which restrains the horizontal offset and left and right sway of the frame cover. The lifting trajectory of the top cover is precise, and it can be accurately aligned with the sealing surface when it falls back, avoiding misalignment of the assembly that causes air leakage and cold energy leakage loss in the cavity.

[0020] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0021] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A cryogenic separation and liquefaction device for liquefied natural gas production, comprising a working frame (1), a frame cover (5) installed at the top of the working frame (1), and a conveying pipe (6) installed at the top of the frame cover (5), characterized in that: It includes a lifting mechanism (2), a receiving mechanism (3), and a processing mechanism (4); The processing mechanism (4) includes a processing bucket frame (404), and a plurality of processing bucket frames (404) are equidistantly arranged in the inner cavity of the working frame (1). Each processing bucket frame (404) is equipped with a sealing cover (409). Both sides of the inner cavity of the processing bucket frame (404) are equipped with blocking inclined plates (410), and the blocking inclined plates (410) on both sides are distributed in a staggered structure. The bottom of the inner cavity of the processing bucket frame (404) at the top and middle are equipped with blocking plates with a staggered structure.

2. The cryogenic separation and liquefaction device for liquefied natural gas production according to claim 1, characterized in that: The bottom sealing cap (409) is connected to the bottom of the middle processing bucket frame (404), and the top of the middle sealing cap (409) is connected to the bottom of the top processing bucket frame (404). Both the processing bucket frame (404) and the sealing cap (409) have a funnel-shaped structure.

3. A cryogenic separation and liquefaction device for liquefied natural gas production according to claim 2, characterized in that: The working frame (1) is equipped with a working valve pipe (401) that connects to the external conveying mechanism at the bottom left side. The right end of the working valve pipe (401) passes through the working frame (1) and connects to the bottom side of the processing bucket frame (404). The processing bucket frame (404) has conveying air holes (408) around its inner cavity, and the conveying air holes (408) have a spiral structure.

4. A cryogenic separation and liquefaction device for liquefied natural gas production according to claim 3, characterized in that: A connecting pipe (405) is installed at the bottom right side of the processing bucket frame (404) relative to the conveying air hole (408). A connecting cavity (407) is opened on the right side of the inner cavity of the working frame (1). A connecting valve pipe (406) connected to an external heat exchange mechanism is installed at the corresponding position of the connecting cavity (407) at the bottom right side of the working frame (1). One end of the connecting pipe (405) away from the processing bucket frame (404) is connected to one side of the inner cavity of the working frame (1). A connecting hole is opened at the corresponding position of the connecting pipe (405) on one side of the inner cavity of the connecting cavity (407).

5. A cryogenic separation and liquefaction device for liquefied natural gas production according to claim 4, characterized in that: The working frame (1) has a connecting slot (403) on the left side of its inner cavity. The upper left side of the processing bucket frame (404) is equipped with a discharge valve pipe. The connecting slot (403) has a discharge hole on the right side corresponding to the discharge valve pipe. The working frame (1) has a discharge pipe (402) connected to an external heat exchange mechanism on the left side corresponding to the connecting slot (403). The connecting slot (403) has a discharge round opening on the inner cavity corresponding to the discharge pipe (402). The processing bucket frame (404) has a connection port on the upper left side between the discharge valve pipe and the conveying air hole (408).

6. A cryogenic separation and liquefaction device for liquefied natural gas production according to claim 5, characterized in that: The top of the sealing cap (409) is equipped with a spiral air pipe (412), the top of the spiral air pipe (412) is connected to the bottom of the conveying pipe (6), and a number of blocking arc plates (411) are installed at equal intervals on the top and bottom of the opposing side of the blocking inclined plate (410). The side of the inner cavity of the blocking inclined plate (410) away from the working frame (1) is provided with a discharge slot (413), and the top of the inner cavity of the discharge slot (413) is provided with a collection hole slot (414) at the corresponding position of the blocking arc plate (411).

7. A cryogenic separation and liquefaction device for liquefied natural gas production according to claim 1, characterized in that: A collection tank (301) is installed at the bottom of the inner cavity of the working frame (1). Several partition plates (302) are installed at equal intervals at the bottom of the inner cavity of the collection tank (301). A liquid level sensor (303) is installed at the upper left side of the inner cavity of the collection tank (301). The liquid level sensor (303) is electrically connected to the external control center. A placement notch is opened at the bottom of the inner cavity of the working frame (1).

8. A cryogenic separation and liquefaction device for liquefied natural gas production according to claim 1, characterized in that: The upper ends of both sides of the working frame (1) are equipped with mounting frames (201), and the upper ends of both sides of the frame cover (5) are equipped with connecting plates (202). Multiple electric push rods (203) are installed in the inner cavity of the mounting frame (201). The top end of the multiple electric push rods (203) is connected to the bottom end of the connecting plate (202). A stabilizing groove (204) is opened on one side of the top end of the mounting frame (201). A stabilizing slide plate (205) is slidably installed in the inner cavity of the stabilizing groove (204). The top end of the stabilizing slide plate (205) is connected to the bottom end of the connecting plate (202).

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