Double-piston extrusion granulation device and method for continuously and circularly extracting hydrate crystals from strong brine

Abstract

The invention relates to a double-piston extrusion granulation device and method for continuously and circularly extracting hydrate crystals from strong brine. The device comprises a hydrate formation subsystem, a hydrate granulation system and an operation control subsystem, the forming subsystem comprises a reactor shell, a first jacket cavity, a first cooling medium inlet / outlet, a gas source bottle and a stirring impeller, the reactor shell is provided with a water inlet, and the gas source bottle is communicated with the reactor shell through a gas supply pipeline to supply gas and stabilize pressure. The granulation system comprises an extrusion shell, a second jacket cavity, a second cooling medium inlet / outlet, a dual-drive motor, a piston assembly, a pusher and a discharge port, the extrusion shell is located below the reactor shell and receives hydrate slurry through a communication channel, and liquid phase backflow is achieved through a backflow channel. The operation control subsystem is electrically connected with the driving motor and the cooling medium inlet and outlet, so that coordinated control of temperature control, gas supply and extrusion granulation is realized, continuous discharge of a solid phase and closed reflux of a liquid phase are realized, and the stability and efficiency of continuous extraction are improved.

Description

Technical Field

[0001] This invention relates to the field of hydrate generation and separation technology, and in particular to a dual-piston extrusion granulation apparatus and method for continuously cyclically extracting hydrate crystals from concentrated brine. Background Technology

[0002] Hydrate desalination, using water as the reaction medium, leverages the phase transition from liquid water to solid hydrate during gaseous hydrate formation to separate freshwater from salt, and is considered a promising eco-friendly desalination approach. This method is applicable to various salt solution systems, such as seawater, wastewater, produced water, and ultra-high salinity water, theoretically possessing strong adaptability to various operating conditions. However, once hydrate crystals are formed in concentrated brine systems, rapid, stable, and thorough separation and extraction are often difficult to achieve, hindering the long-term industrial-scale application of this technology.

[0003] In the prior art, patent CN107162018B, "An apparatus and method for purifying high-concentration brine using the hydrate method," discloses an apparatus and process for purifying high-concentration brine using the hydrate method. It mainly includes a hydrate generation flow pipeline device, a three-phase separator, a hydrate decomposition device, a bubble generator embedded in the pipeline device, and other auxiliary devices. Pretreated low-temperature seawater and CO2 are reacted in the hydrate generation flow pipeline device to generate CO2 hydrate, which then enters the three-phase separator to separate the gas, the higher-concentration seawater, and the CO2 hydrate. The CO2 hydrate enters the hydrate decomposition device to obtain relatively pure water. The separated CO2 gas is recycled, the separated higher-concentration seawater is sent to a salt crystallization pond, and the separated relatively pure water is used in the salt washing process.

[0004] However, under the actual requirements of engineering and continuous operation, the above technical solutions still have certain limitations: First, the temperature of the hydrate formation process mainly depends on deep seawater, and the temperature conditions are relatively simple, which may limit the compatibility with other crystallizing agents / guest gases such as cyclopentane, refrigerant, and methane, thus affecting purification efficiency and operating condition expansion; Second, parameters such as pressure, temperature, and seawater volume are in a dynamic state during the hydrate formation process, and there is a lack of effective detection and feedback correction methods, which can easily have an adverse impact on hydrate formation efficiency and formation time; Third, the hydrate formation and separation process is a non-continuous cycle, and the production efficiency is relatively low. Fourth, achieving complete gas-liquid-solid separation using a three-phase separator is difficult, posing a risk of incomplete separation and potentially inducing hydrate decomposition during the separation process; fifth, when the gas-liquid mixer and bubble generator operate asynchronously, the CO2 bubbles mix unevenly and insufficiently with the high-salinity seawater, thus affecting hydrate formation efficiency; sixth, controlling the amount of hydrate formation to avoid pipeline blockage may not be able to balance high yield with low blockage risk; seventh, the lack of an effective detection and evaluation mechanism for the purification efficiency of high-concentration brine makes it difficult to promptly identify and correct problems and loopholes in the process operation.

[0005] In view of the above problems, this invention is proposed. Summary of the Invention

[0006] This invention discloses a dual-piston extrusion granulation device and method for continuously cyclically extracting hydrate crystals from concentrated brine, aiming to solve the technical problems existing in the prior art.

[0007] To achieve the above objectives, according to one aspect of the present invention, a dual-piston extrusion granulation apparatus for continuously cyclically extracting hydrate crystals from concentrated brine is provided, comprising a hydrate formation subsystem, a hydrate particle making system, and an operation control subsystem. The hydrate formation subsystem includes a reactor shell, a first cooling medium inlet, a first cooling medium outlet, a gas source cylinder, and a stirring impeller. A water inlet is located at the top of the reactor shell, and a first jacket is fitted around the outer side of the reactor shell, forming a first jacket cavity with the outer wall of the reactor shell. The first cooling medium inlet and the first cooling medium outlet are located on the same outer side of the reactor shell and communicate with the first jacket cavity. The gas source cylinder is located outside the reactor shell and communicates with the reactor shell via a gas supply pipeline. A stirring impeller is located inside the reactor shell. The hydrate particle-forming system includes an extrusion shell, a second cooling medium inlet, a second cooling medium outlet, a drive motor assembly, a piston assembly, a pusher, and a discharge port. The extrusion shell is a long cylindrical shape, with its long side arranged horizontally and located below the reactor shell. The reactor shell and the extrusion shell are connected by a connecting channel, and a reflux channel for liquid phase reflux is provided. A second jacket is fitted on the outside of the extrusion shell, forming a second jacket cavity with the outer wall of the extrusion shell. The second jacket cavity is connected to the first jacket cavity. The second cooling medium inlet and the second cooling medium outlet are located on the same outer side of the extrusion shell and are connected to the second jacket cavity. The drive motor assembly has two drive motors, respectively located at both ends of the extrusion shell. The piston assembly is located inside the extrusion shell and reciprocates axially. The pusher is located at the discharge end of the extrusion shell and is connected to the discharge port. The operation control subsystem is electrically connected to the drive motor assembly, the first cooling medium inlet, the first cooling medium outlet, the second cooling medium inlet, and the second cooling medium outlet, respectively, to control the continuous granulation and discharge of the hydrate slurry and the continuous cyclic extraction formed by liquid phase reflux.

[0008] As a preferred technical solution, an optical fiber probe assembly is provided on the outside of the reactor shell. The optical fiber probe assembly is located on the same side between the first cooling medium inlet and the first cooling medium outlet, and is connected to the first jacket cavity.

[0009] As a preferred technical solution, a Raman spectrometer assembly is connected to the side of the fiber optic probe assembly away from the reactor shell.

[0010] As a preferred technical solution, the fiber optic probe assembly includes at least one fiber optic probe, and the Raman spectrometer assembly includes at least one Raman spectrometer.

[0011] As a preferred technical solution, a scraper is also provided inside the reactor shell, and the scraper is set close to the inner wall of the reactor shell.

[0012] As a preferred technical solution, a scraper pusher is provided in connection with the scraper drive. The scraper pusher is located outside the reactor shell and is electrically connected to the operation control subsystem.

[0013] As a preferred technical solution, the hydrate formation subsystem also includes a blade actuator, which is connected to the stirring impeller and electrically connected to the motion control subsystem.

[0014] As a preferred technical solution, a control valve is installed on the gas supply pipeline, and the gas inlet and water inlet of the gas supply pipeline are spaced apart.

[0015] As a preferred technical solution, the hydrate formation subsystem also includes a weighing device, which is located below the gas source cylinder and electrically connected to the motion control subsystem.

[0016] As a preferred technical solution, a check valve is provided on the reflux channel, and the reflux direction points towards the reactor shell.

[0017] As a preferred technical solution, the piston assembly includes a first piston and a second piston. The first piston and the second piston are arranged opposite each other along the axial direction of the extrusion shell and are respectively connected to two drive motors located at both ends of the extrusion shell.

[0018] According to another aspect of the present invention, a method for continuously cyclically extracting hydrate crystals from concentrated brine using the above-described dual-piston extrusion granulation apparatus is provided, comprising the following steps: Simultaneously, cooling medium is introduced into the first jacketed cavity of the reactor shell and the second jacketed cavity of the extrusion shell; A concentrated brine sample is injected into the reactor shell through the inlet; hydrates are introduced into the reactor shell through the gas supply pipe to form gas. The stirring impeller is activated to mix and transfer the gas and liquid phases inside the reactor shell, forming a hydrate slurry; The hydrate slurry is transported to the extrusion shell through the connecting channel. The operation control subsystem controls the drive motor assembly to drive the piston assembly to reciprocate within the extrusion shell, so that the hydrate slurry sequentially completes the cycle of slurry intake, slurry movement, slurry extrusion, particle discharge and return to the initial position. The hydrate particles formed are then discharged through the outlet by the pusher. The separated liquid phase flows back to the reactor shell through the reflux channel, and the reflux direction is kept pointing towards the reactor shell by the action of the check valve; Repeat the above process of starting the stirring impeller to liquid phase reflux to achieve continuous generation of hydrate crystals, continuous granulation and discharge, and continuous cyclic extraction formed by liquid phase reflux.

[0019] The technical solution adopted in this invention can achieve at least one of the following beneficial effects: 1. This invention integrates the hydrate formation subsystem and the hydrate particle-forming system to form a process path of "continuous solid phase discharge and liquid phase reflux closed loop", which transforms the generation and extraction of hydrate crystals from intermittent to continuous cyclic operation, reduces operating condition fluctuations and improves continuous extraction efficiency and stability.

[0020] 2. The present invention sets jackets in the reactor shell and the extrusion shell respectively and introduces cooling medium to achieve zoned temperature control in the forming and granulation stages, reduce the risk of local heating and cooling loss during the extrusion process, and inhibit the decomposition of hydrates during the extrusion and solid-liquid separation process, thereby improving the stability of granule forming and the overall conversion rate.

[0021] 3. The present invention adopts a double piston reciprocating extrusion granulation method, which enables the hydrate slurry to complete the cycle of intake, transfer, extrusion, discharge and reset in sequence, thereby enhancing the ability of rapid solid-liquid separation and continuous discharge of granules, shortening the separation time, reducing the probability of blockage / retention and improving the continuity of granule extraction.

[0022] 4. This invention collects, records, and coordinates the temperature, pressure, cooling medium flow, and extrusion action parameters through an operation control subsystem. It can also be combined with online monitoring components to achieve process status visualization and traceability, providing reliable data support for accurate calculation of hydrate conversion rate and purification efficiency, as well as optimization of operating conditions. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below, forming part of the present invention. The illustrative embodiments of the present invention and their descriptions explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings: Figure 1 This is a schematic diagram of a dual-piston extrusion granulation device for continuously circulating and extracting hydrate crystals from concentrated brine according to the present invention. Figure 2 This is a schematic diagram of the slurry intake stage in the hydrate granulation process of the present invention; Figure 3 This is a schematic diagram of the slurry movement stage in the hydrate granulation process of the present invention; Figure 4 This is a schematic diagram of the slurry extrusion stage in the hydrate granulation process of the present invention; Figure 5 This is a schematic diagram of the particle discharge stage in the hydrate granulation process of the present invention. Figure 6 This is a schematic diagram of the return to the initial position stage in the hydrate granulation process of the present invention.

[0024] Explanation of reference numerals in the attached figures: 1. Blade actuator; 2. Scraper actuator; 3. Inlet; 4. Weighing device; 5. Gas source cylinder; 6. Control valve; 7. Reactor shell; 8. Cooling medium inlet assembly; 81. First cooling medium inlet; 82. Second cooling medium inlet; 9. Cooling medium outlet assembly; 91. First cooling medium outlet; 92. Second cooling medium outlet; 10. Agitator impeller; 11. Scraper; 12. Fiber optic probe assembly; 121. First fiber optic probe; 122. Second fiber optic probe 13. Head; 14. Raman spectrometer assembly; 15. First Raman spectrometer; 16. Second Raman spectrometer; 17. Extrusion housing; 18. Drive motor assembly; 19. First drive motor; 10. Second drive motor; 11. Piston rod assembly; 12. First piston rod; 13. Second piston rod; 14. Piston assembly; 15. First piston; 16. Second piston; 17. Check valve; 18. Pusher; 19. Discharge port; 20. Operation control subsystem. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. In the description of this invention, it should be noted that the term "or" is generally used to include the meaning of "and / or," unless otherwise expressly indicated.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or a magnetic connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, in the description of this application, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0027] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0028] To address the problems existing in the prior art, embodiments of the present invention provide a dual-piston extrusion granulation device for continuously circulating extraction of hydrate crystals from concentrated brine, such as... Figures 1-6As shown, the system includes a hydrate formation subsystem, a hydrate particle making system, and an operation control subsystem 21. The hydrate formation subsystem is located above the hydrate particle making system and is used to achieve sufficient contact between concentrated brine and hydrate forming gas and generate hydrate crystals under controlled temperature and pressure conditions, and to monitor the generation process online. The hydrate particle making system is used to continuously process the generated hydrate slurry into hydrate granules and discharge them, while simultaneously allowing the separated liquid phase to flow back to the formation zone to achieve continuous circulation. The operation control subsystem 21 is used to collect, record, and coordinate the control of key process parameters during the operation of the device to ensure that the continuous generation, continuous granulation, and continuous extraction of hydrate crystals are stable and controllable.

[0029] like Figure 1 As shown, the hydrate formation subsystem includes a reactor shell 7, with an inlet 3 at the top to inject concentrated brine samples into the reactor shell 7; a jacket structure, namely the first jacket, is provided on the outer periphery of the reactor shell 7, which surrounds the outer wall of the reactor shell 7 and forms a first jacket cavity for the flow of cooling medium between the jacket and the outer wall of the reactor shell 7; a cooling medium inlet assembly 8 and a cooling medium outlet assembly 9 are respectively connected to the jacket cavity to input and discharge cooling medium into the jacket cavity, thereby achieving heat exchange and temperature control of the reactor shell 7 through the circulation of cooling medium in the jacket cavity. Specifically, the cooling medium inlet assembly 8 and the cooling medium outlet assembly 9 are used to input and discharge cooling medium into and out of the jacket, respectively. The cooling medium inlet assembly 8 includes a first cooling medium inlet 81, and the cooling medium outlet assembly 9 includes a first cooling medium outlet 91. The first cooling medium inlet 81 and the first cooling medium outlet 91 are both located on the same side of the reactor shell 7 and are connected to the jacket of the reactor shell 7 to form a compact inlet and outlet pipeline arrangement on this side and constitute a circulating cooling loop of the reactor shell 7. Preferably, the first cooling medium inlet 81 and the first cooling medium outlet 91 are arranged at intervals along the height direction of the reactor shell 7, and the first cooling medium outlet 91 is located above the first cooling medium inlet 81, so that the cooling medium forms a stable flow channel in the jacket, thereby reducing stagnation and temperature unevenness in the jacket, improving temperature control stability and heat exchange efficiency, and reducing interference of pipeline crossing arrangement on the inlet 3, detection / wiring and maintenance operations.

[0030] Gas source cylinder 5 is connected to reactor shell 7 via control valve 6 and gas supply pipeline. The gas inlet of the gas supply pipeline is located at the upper part of reactor shell 7 and is spatially separated from and spaced apart from water inlet 3 (preferably located next to water inlet 3) to avoid liquid impact / backflow on the gas supply channel during water intake and reduce gas-liquid interference, thereby providing hydrate formation gas to reactor shell 7 and maintaining reaction pressure. Gas source cylinder 5 is arranged on weighing device 4, which is used to weigh gas source cylinder 5 in real time to obtain gas consumption information. Inside reactor shell 7, there is a stirring impeller 10 and a scraper 11. The stirring impeller 10 is used to stir and mix the gas and liquid phases inside reactor shell 7. The scraper 11 is set close to the inner wall of reactor shell 7 to scrape off the crystals attached to the wall surface. Blade pusher 1 is drivenly connected to stirring impeller 10, and scraper pusher 2 is drivenly connected to scraper 11, thereby realizing independent drive and speed regulation of stirring impeller 10 and scraper 11.

[0031] A fiber optic probe assembly 12 is installed on the reactor shell 7. The fiber optic probe assembly 12 includes a first fiber optic probe 121 and a second fiber optic probe 122. Both the first fiber optic probe 121 and the second fiber optic probe 122 extend into the reactor shell 7 from the same side wall and are arranged vertically at intervals along the height of the reactor shell 7. Preferably, the first fiber optic probe 121 is located above the second fiber optic probe 122 to perform in-situ detection of the hydrate formation state at different height positions, thereby improving the representativeness and reliability of process monitoring. Figure 1 As shown, the first cooling medium inlet 81, the first cooling medium outlet 91, the first fiber optic probe 121, and the second fiber optic probe 122 are all located on the same side of the reactor shell 7. Preferably, the first cooling medium inlet 81 is located at the lower part of this side, and the first cooling medium outlet 91 is located at the upper part of this side, so that the cooling medium forms a bottom-up flow path within the jacket. The first fiber optic probe 121 and the second fiber optic probe 122 are arranged vertically at intervals along the height direction of the reactor shell 7, and are located within the height range between the first cooling medium inlet 81 and the first cooling medium outlet 91, with the first fiber optic probe 121 located above the second fiber optic probe 122. Optionally, the sequence from top to bottom is the first cooling medium outlet 91, the first fiber optic probe 121, the second fiber optic probe 122, and the first cooling medium inlet 81, so that the detection position is within the effective heat exchange coverage area of ​​the jacket, and the hydrate formation state of the upper and lower regions is characterized respectively, improving the representativeness and reliability of process monitoring.

[0032] The Raman spectrometer assembly 13 is located outside the reactor shell 7 and connected to the fiber optic probe assembly 12. The Raman spectrometer assembly 13 includes a first Raman spectrometer 131 and a second Raman spectrometer 132, which are respectively connected to the first fiber optic probe 121 and the second fiber optic probe 122 to realize in-situ spectral detection of the hydrate formation process.

[0033] The operation control subsystem 21 is electrically connected to the weighing device 4, control valve 6, blade actuator 1, scraper actuator 2, cooling medium inlet assembly 8 / cooling medium outlet assembly 9 and Raman spectrometer assembly 13, respectively, and is used to collect, record and coordinate control of temperature, pressure, gas consumption, stirring and scraper operation parameters and detection signals.

[0034] In this hydrate formation subsystem, the operation control subsystem 21 controls the cooling medium to enter the first jacket of the reactor shell 7 through the first cooling medium inlet 81 and exit through the first cooling medium outlet 91, so that the reactor shell 7 is maintained at the temperature window required for hydrate formation. Since the first cooling medium inlet 81 and the first cooling medium outlet 91 are concentrated on the same side of the reactor shell 7, the inlet and outlet pipelines of the cooling circuit can be arranged nearby on this side and the crossing and detour can be reduced, thereby reducing the installation complexity and external heat exchange interference, which is conducive to forming a more stable jacket circulation flow and temperature field distribution. Meanwhile, hydrate-forming gas is introduced into the reactor shell 7 via control valve 6, and automatic gas replenishment is implemented when the gas is consumed to maintain stable pressure. Weighing device 4 monitors the mass change of gas source bottle 5 in real time, providing a data basis for calculating gas consumption and hydrate conversion / purification efficiency. Stirring impeller 10 enhances gas-liquid contact and mass and heat transfer, while scraper 11 promptly removes crystal deposits on the inner wall of reactor shell 7, reducing the impact of scaling and wall adhesion on heat exchange and mixing, thereby improving cooling and mixing effects and increasing the hydrate crystal formation rate and conversion rate. In addition, fiber optic probe assembly 12 and Raman spectrometer assembly 13 collect information such as hydrate structure, guest molecule inclusion, and cage-like characteristics online, making the formation process monitorable, traceable, and usable for mechanism analysis and operating condition optimization. Through the above-mentioned structure and control coordination of the formation zone, efficient formation of hydrate crystals in concentrated brine can be achieved under stable temperature and pressure conditions, providing a stable source of hydrate slurry and reliable data support for subsequent continuous granulation and extraction.

[0035] like Figure 1As shown, the hydrate granulation system includes an extrusion shell 14, which is a long cylindrical structure extending horizontally along its long side and positioned below the reactor shell 7. The upper part of the extrusion shell 14 is connected to the bottom of the reactor shell 7 via a connecting channel, allowing the hydrate slurry generated by the hydrate formation subsystem to enter the extrusion shell 14 for subsequent extrusion granulation. The outer side of the extrusion shell 14 is also provided with a second jacket for heat exchange and temperature control, forming a second jacket cavity for cooling medium flow between the jacket and the outer wall of the extrusion shell 14. Specifically, the cooling medium inlet assembly 8 includes... The cooling medium inlet 82 and the cooling medium outlet assembly 9 include a second cooling medium outlet 92. The second cooling medium inlet 82 and the second cooling medium outlet 92 are both located on the same side of the extrusion shell 14 and communicate with its jacket. Preferably, the second cooling medium outlet 92 is located above the second cooling medium inlet 82, so that the cooling medium forms a bottom-up flow path in the jacket of the extrusion shell 14. This stabilizes the temperature of the slurry / granules in the extrusion shell 14 during the extrusion granulation process, reduces the impact of temperature rise or local temperature loss during the extrusion process on the stability of the hydrate, and ensures a continuous and stable granulation process.

[0036] Drive motor assemblies 15 are respectively provided at both ends of the extrusion shell 14, wherein the drive motor assembly 15 includes a first drive motor 151 and a second drive motor 152; a piston assembly 17 is provided inside the extrusion shell 14, the piston assembly 17 includes a first piston 171 and a second piston 172, the first piston 171 and the second piston 172 are arranged opposite each other along the axial direction of the extrusion shell 14 and can reciprocate within the extrusion shell 14; a piston rod assembly 16 includes a first piston rod 161 and a second piston rod 162, one end of the first piston rod 161 and... The first piston 171 is connected to the first drive motor 151 at one end, and the second piston rod 162 is connected to the second piston 172 at one end and to the second drive motor 152 at the other end. Thus, the first drive motor 151 and the second drive motor 152 drive the first piston 171 and the second piston 172 to achieve independent or coordinated reciprocating motion, so as to form an adjustable suction volume and extrusion molding space in the extrusion shell 14, and realize the "suction-transfer-extrusion-discharge-reset" cycle processing of the hydrate slurry. A pusher 19 is provided near the discharge end of the extrusion shell 14 and connected to the discharge port 20. The pusher 19 is used to push out the extruded hydrate granules and discharge them through the discharge port 20. At the same time, a reflux channel for liquid phase reflux is provided between the extrusion shell 14 and the reactor shell 7. A check valve 18 is provided on the reflux channel with the reflux direction pointing towards the reactor shell 7, so that the liquid phase separated from the hydrate slurry during the extrusion process can flow back to the reactor shell 7 in one direction and prevent backflow in the reflux channel. This creates a continuous circulation path of "continuous solid phase discharge and closed-loop liquid phase reflux" between the forming zone and the granulation zone.

[0037] In this hydrate particle-forming system, the operation control subsystem 21 (in conjunction with the drive motor assembly 15, etc.) controls the first piston 171 and the second piston 172 to perform cyclical operations, wherein: Figure 2 The diagram shows the slurry intake stage. The operation control subsystem 21 controls the first drive motor 151 to drive the first piston 171 to retract along the axial direction of the extrusion shell 14 towards the side of the first drive motor 151. At the same time, it controls the second drive motor 152 to drive the second piston 172 to retract along the axial direction of the extrusion shell 14 towards the side of the second drive motor 152. That is, the first piston 171 and the second piston 172 retract in opposite directions, thereby forming a suction volume in the middle of the extrusion shell 14 to draw in the hydrate slurry. The intake volume can be adjusted by the retraction stroke and position of the two pistons. like Figure 3 The diagram shows the slurry movement stage. The operation control subsystem 21 controls the first drive motor 151 to drive the first piston 171 axially along the extrusion shell 14 towards the side of the second drive motor 152, while simultaneously controlling the second drive motor 152 to drive the second piston 172 axially along the extrusion shell 14 towards the side of the first drive motor 151. That is, the first piston 171 and the second piston 172 move in opposite directions, thereby... Figure 2 The hydrate slurry inhaled in each stage is pushed and transported to the squeezing zone. After the slurry reaches the squeezing zone, the operation control subsystem 21 can control the second piston 172 to remain stationary while the first piston 171 continues to advance in the opposite direction (or vice versa), so as to achieve compression preparation and stabilize the positioning of the slurry in the squeezing zone before entering the squeezing stage. like Figure 4 The diagram shows the slurry extrusion stage. After the slurry is positioned in the extrusion zone, the operation control subsystem 21 controls the second piston 172 to remain in a fixed position, while simultaneously controlling the first drive motor 151 to drive the first piston 171 to continue advancing along the axial direction of the extrusion shell 14 towards the second piston 172, applying a set extrusion force to the hydrate slurry in the extrusion zone, causing the slurry to be compacted and formed within the confined space of the extrusion shell 14 and undergoing solid-liquid separation. Optionally, the first piston 171 can also be controlled to remain fixed, while the second piston 172 advances in opposite directions to complete the extrusion, in order to meet the extrusion direction and force requirements under different working conditions. like Figure 5The diagram shows the particle discharge stage. After extrusion molding is completed, the operation control subsystem 21 maintains the extrusion pressure in the extrusion zone (e.g., keeping the first piston 171 in the push-stop or hold position), so that the formed hydrate particles are stably pushed to the discharge end. Subsequently, the pusher 19 moves in the direction pointing to the discharge port 20, pushing the particles out from the discharge end of the extrusion shell 14 and discharging them through the discharge port 20 (preferably downward discharge). At the same time, the liquid phase precipitated from the slurry during extrusion flows through the reflux channel under the action of pressure difference and flows back to the reactor shell 7 in one direction through the check valve 18. The check valve 18 is used to ensure that the reflux direction points to the reactor shell 7 and to prevent backflow, thereby maintaining a closed-loop circulation between the hydrate formation subsystem and the hydrate particle making system. like Figure 6 The diagram shows the return to the initial position stage. After the particles are discharged and the liquid phase is refluxed, the operation control subsystem 21 controls the first drive motor 151 to drive the first piston 171 to retract along the axial direction of the extrusion shell 14 towards the first drive motor 151. At the same time, it controls the second drive motor 152 to drive the second piston 172 to retract along the axial direction of the extrusion shell 14 towards the second drive motor 152. That is, the first piston 171 and the second piston 172 retract back to their initial positions in opposite directions, thereby restoring the suction space in the middle of the extrusion shell 14 and entering the next slurry suction and extrusion granulation cycle.

[0038] Through the above-mentioned structure and action coordination, on the one hand, the continuous connection of the suction, transfer, extrusion and discharge processes can be achieved by using the reciprocating double pistons, which improves the continuous extraction capability of hydrate granules and reduces the fluctuations caused by intermittent operation; on the other hand, the jacket temperature control of the extrusion shell 14 (second cooling medium inlet 82 / second cooling medium outlet 92) can maintain the stable temperature conditions for the existence of hydrates during the extrusion and solid-liquid separation process, suppress the decomposition of hydrates caused by local heating, and the one-way backflow function of the check valve 18 can avoid backflow disturbance and backflow risk, thereby achieving faster and more stable hydrate granule forming and discharge, and providing support for the overall "continuous circulation extraction of hydrate crystals from concentrated brine" operation stability and purification efficiency improvement.

[0039] Through the above structural design, the embodiment of the present invention uses the reactor shell 7 to form a hydrate formation subsystem. Stable temperature control of the formation zone is achieved through the jacketed circulating heat exchange formed by the cooling medium inlet component 8 and the cooling medium outlet component 9. The gas source bottle 5, control valve 6 and weighing device 4 are combined to achieve the supply of hydrate formation gas, constant pressure maintenance and gas consumption measurement. At the same time, the fiber optic probe component 12 and Raman spectrometer component 13 are used to achieve online spectral monitoring of the hydrate formation process, so that the formation process and key parameters can be monitored, recorded and traced. Based on this, the device uses the extrusion shell 14 to form a hydrate particle making system. The first drive motor 151 and the second drive motor 152 drive the first piston 171 and the second piston 172 respectively to perform a cyclic action of back-to-back suction, back-to-back material transfer, directional extrusion, material discharge, and back-to-back reset. The hydrate slurry is continuously extruded into hydrate granules and discharged through the discharge port 20. At the same time, the check valve 18 realizes the one-way backflow of the separated liquid phase to the reactor shell 7, thereby forming a continuous circulation path of "continuous external discharge of solid phase and closed-loop backflow of liquid phase" between the formation zone and the granulation zone. The operation control subsystem 21 collects, records and coordinates the control of temperature, pressure, gas consumption, speed and extrusion granulation parameters, so that the hydrate crystal formation, solid-liquid separation and granule extraction process can be continuously and stably operated. Compared with existing technologies, the present invention has at least the following beneficial technical effects: it enables the rapid generation and continuous cyclic extraction of hydrate crystals from concentrated brine under controlled temperature and pressure conditions; it achieves rapid solid-liquid separation and continuous discharge of granules through extrusion granulation, reducing fluctuations caused by intermittent operation and improving extraction efficiency; it reduces the risk of localized cooling and backflow through jacketed heat exchange and unidirectional reflux structure, improving system operational stability; and it obtains reliable experimental data and structural information through gas consumption measurement and online Raman monitoring, providing support for accurate calculation of hydrate conversion rate and purification efficiency and optimization of operating conditions.

[0040] This invention also provides a method for continuously circulating extraction of hydrate crystals from concentrated brine using the above-mentioned extrusion granulation device, comprising: S1: Temperature control preparation; Cooling medium is introduced into the jacket of reactor shell 7 through cooling medium inlet assembly 8 and cooling medium outlet assembly 9 and circulated for heat exchange, so that reactor shell 7 reaches and stabilizes within the target temperature range required for hydrate formation; at the same time, cooling medium is introduced into the jacket of extrusion shell 14 through second cooling medium inlet 82 and second cooling medium outlet 92 and circulated for heat exchange, so that extrusion shell 14 is maintained at the temperature condition where hydrates are stable, thereby reducing the risk of temperature rise and local temperature loss during the extrusion granulation process; S2: System replacement and gas supply preparation; The gas for hydrate formation in the gas source cylinder 5 is introduced into the reactor shell 7 through the gas supply pipeline via the control valve 6 to replace the reactor shell 7 and the connecting pipeline to remove residual air; then the gas supply continues to make the reactor shell 7 reach the pressure required for hydrate formation, and in the subsequent process, the operation control subsystem 21 cooperates with the control valve 6 to realize gas replenishment and constant pressure control. S3: Feeding and startup are formed; A concentrated brine sample is injected into the reactor shell 7 through the inlet 3. The blade actuator 1 and the scraper actuator 2 are started, so that the stirring impeller 10 and the scraper 11 run at a set speed to enhance gas-liquid contact and mass and heat transfer and to scrape off the crystals attached to the inner wall in time, thereby generating hydrate crystals and forming a flowable hydrate slurry under controlled temperature and pressure conditions. S4: Online monitoring and data recording; The operation control subsystem 21 collects and records key process parameters such as temperature and pressure; the weighing device 4 weighs the gas source cylinder 5 in real time to obtain gas consumption data; the fiber optic probe assembly 12 and the Raman spectrometer assembly 13 perform in-situ spectral monitoring of the hydrate formation process to obtain information on the hydrate structure and formation state, and provide data support for subsequent hydrate conversion rate / purification efficiency calculation and operating condition optimization. S5: Continuous extrusion granulation and liquid phase reflux; The hydrate slurry inside the reactor shell 7 is transported to the extrusion shell 14 through a connecting channel. The operation control subsystem 21 controls the first drive motor 151 and the second drive motor 152 to drive the first piston 171 and the second piston 172 to perform cyclic granulation: First, in the slurry intake stage, the first piston 171 and the second piston 172 are retracted back to their respective drive ends to form an intake volume and intake the slurry; then, in the slurry movement stage, the first piston 171 and the second piston 172 are pushed forward to push the slurry to the extrusion zone; subsequently, in the slurry extrusion stage, one piston is held while the other piston continues to push forward and apply a set extrusion force to compact the slurry and achieve solid-liquid separation; in the particle discharge stage, the pusher 19 discharges the formed particles through the discharge port 20, while the separated liquid phase flows back to the reactor shell 7 in one direction through the check valve 18; finally, in the return to the initial position stage, the first piston 171 and the second piston 172 are retracted back to their original positions to provide space and workstations for the next cycle of intake and extrusion granulation. S6: Continuous cyclic operation; Repeat steps S3 to S5 to continuously generate hydrate slurry in reactor shell 7, continuously extrude and granulate the hydrate particle forming system and discharge the granules, and continuously reflux the liquid phase to the formation zone to form a closed loop; the operation control subsystem 21 continuously coordinates, controls and records the process parameters until the predetermined extraction amount or operation termination condition is reached.

[0041] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other modifications under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these modifications are within the protection scope of the present invention.

Claims

1. A dual-piston extrusion granulation device for continuously circulating extraction of hydrate crystals from concentrated brine, characterized in that, It includes a hydrate formation subsystem, a hydrate particle building system, and an operation control subsystem; The hydrate formation subsystem includes a reactor shell, a first cooling medium inlet, a first cooling medium outlet, a gas source cylinder, and a stirring impeller. The reactor shell has a water inlet at its upper part, and a first jacket is fitted over its outer side, forming a first jacket cavity with the outer wall of the reactor shell. The first cooling medium inlet and the first cooling medium outlet are located on the same outer side of the reactor shell and communicate with the first jacket cavity. The gas source cylinder is located outside the reactor shell and communicates with the reactor shell via a gas supply pipeline. A stirring impeller is located inside the reactor shell. The hydrate particle-forming system includes an extrusion shell, a second cooling medium inlet, a second cooling medium outlet, a drive motor assembly, a piston assembly, a pusher, and a discharge port. The extrusion shell is elongated cylindrical with its long side arranged horizontally and located below the reactor shell. The reactor shell and the extrusion shell are connected by a connecting channel, which includes a reflux channel for liquid phase reflux. A second jacket is fitted around the outside of the extrusion shell, forming a second jacket cavity with the outer wall of the extrusion shell. The second jacket cavity is connected to the first jacket cavity. The second cooling medium inlet and the second cooling medium outlet are located on the same outer side of the extrusion shell and are connected to the second jacket cavity. The drive motor assembly has two drive motors, respectively located at both ends of the extrusion shell. The piston assembly is located inside the extrusion shell and reciprocates axially. The pusher is located at the discharge end of the extrusion shell and is connected to the discharge port. The operation control subsystem is electrically connected to the drive motor assembly, the first cooling medium inlet, the first cooling medium outlet, the second cooling medium inlet, and the second cooling medium outlet, respectively, to control the continuous granulation and discharge of the hydrate slurry and the continuous cyclic extraction formed by liquid phase reflux.

2. The dual-piston extrusion granulation apparatus according to claim 1, characterized in that, The reactor shell is provided with an optical fiber probe assembly on the outside. The optical fiber probe assembly is located on the same side between the first cooling medium inlet and the first cooling medium outlet, and is connected to the first jacket cavity.

3. The dual-piston extrusion granulation apparatus according to claim 2, characterized in that, The fiber optic probe assembly is connected to a Raman spectrometer assembly on the side away from the reactor shell.

4. The dual-piston extrusion granulation apparatus according to claim 3, characterized in that, The fiber optic probe assembly includes at least one fiber optic probe, and the Raman spectrometer assembly includes at least one Raman spectrometer.

5. The dual-piston extrusion granulation apparatus according to claim 1, characterized in that, The reactor shell is also equipped with a scraper, which is set close to the inner wall of the reactor shell.

6. The dual-piston extrusion granulation apparatus according to claim 5, characterized in that, A scraper pusher is connected to the scraper drive. The scraper pusher is located outside the reactor shell and is electrically connected to the operation control subsystem.

7. The dual-piston extrusion granulation apparatus according to claim 1, characterized in that, The hydrate formation subsystem also includes a blade actuator, which is drivenly connected to the stirring impeller and electrically connected to the motion control subsystem.

8. The dual-piston extrusion granulation apparatus according to claim 1, characterized in that, The gas supply pipeline is equipped with a control valve, and the gas inlet and the water inlet of the gas supply pipeline are spaced apart.

9. The dual-piston extrusion granulation apparatus according to claim 1, characterized in that, The hydrate formation subsystem also includes a weighing device located below the gas source cylinder and electrically connected to the motion control subsystem.

10. The dual-piston extrusion granulation apparatus according to claim 1, characterized in that, The reflux channel is equipped with a check valve, and the reflux direction is towards the reactor shell.

11. The dual-piston extrusion granulation apparatus according to claim 1, characterized in that, The piston assembly includes a first piston and a second piston, which are arranged opposite to each other along the axial direction of the extrusion housing and are respectively connected to the two drive motors located at both ends of the extrusion housing.

12. A method for continuously circulating extraction of hydrate crystals from concentrated brine using the dual-piston extrusion granulation apparatus according to any one of claims 1-11, characterized in that, Includes the following steps: Simultaneously, cooling medium is introduced into the first sleeve cavity of the reactor shell and the second jacket cavity of the extrusion shell; A concentrated brine sample is injected into the reactor shell through the inlet; hydrates are introduced into the reactor shell through the gas supply pipe to form gas. The stirring impeller is activated to mix and transfer the gas and liquid phases within the reactor shell, forming a hydrate slurry. The hydrate slurry is transported to the extrusion shell through the connecting channel. The control subsystem controls the drive motor assembly to drive the piston assembly to reciprocate within the extrusion shell, so that the hydrate slurry sequentially completes the cycle of slurry intake, slurry movement, slurry extrusion, particle discharge and return to the initial position. The hydrate particles formed are then discharged through the discharge port by the pusher. The separated liquid phase flows back to the reactor shell through the reflux channel, and the reflux direction is maintained towards the reactor shell under the action of the check valve; Repeat the above process of starting the stirring impeller to the liquid phase reflux to achieve continuous generation of hydrate crystals, continuous granulation and discharge, and continuous cyclic extraction formed by liquid phase reflux.

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