A sediment plume active suppression system and method for deep sea mining

Abstract

The application provides a sediment plume active inhibition system and method for deep-sea mining, and belongs to the technical field of deep-sea mining engineering and marine environment protection. The system is integrated in a deep-sea mining vehicle and comprises a polymer storage and supply module, an online mixing module, a high-pressure metering and conveying module, a multi-point array spraying module and an active control unit. A polymer working solution is formed by online mixing of a natural polymer and seawater, is conveyed by high-pressure metering, and is sprayed into a sediment plume source area by the spraying module arranged around the mining vehicle. The active control unit controls the preparation, conveying and spraying of the polymer working solution according to the working state of the mining vehicle. The designed system and the natural polymer mother liquor can promote flocculation of fine sediment particles and accelerate near-field settlement in the initial stage of plume generation, so as to reduce the diffusion range of the sediment plume.

Description

Technical Field

[0001] This invention belongs to the field of deep-sea mining engineering and marine environmental protection technology, and particularly relates to an active sediment plume suppression system and method for deep-sea mining. Background Technology

[0002] The extraction of deep-sea polymetallic nodules and other mineral resources typically relies on deep-sea mining vehicles to travel, collect, and transport minerals along the seabed. During their movement and collection, these vehicles disturb surface sediments, causing fine sediment particles to enter the water and form sediment plumes. These sediment plumes remain suspended in the deep-sea environment for extended periods and spread over a wide area, potentially causing adverse effects on benthic ecosystems and near-bottom water environments.

[0003] Existing deep-sea mining plume control solutions primarily address issues through methods such as suction, containment, discharge height regulation, or post-discharge sedimentation treatment. However, these solutions fall short in controlling the rapid aggregation of fine particles and near-field sedimentation in the plume source area. Deep-sea operations are characterized by high pressure and limited space, and the external structure of mining vehicles is easily affected by seabed topography, ore, and sediment disturbance. Therefore, a plume suppression system that can be integrated with deep-sea mining vehicles, actively releases flocculating media in the early stages of plume formation, and adapts to deep-sea conditions is needed. Summary of the Invention

[0004] To address the aforementioned problems, the first aspect of this invention proposes an active sediment plume suppression system for deep-sea mining. The system is integrated onto a deep-sea mining vehicle and includes a polymer storage and supply module, an online mixing module, a high-pressure metering and conveying module, a multi-point array injection module, and an active control unit. The polymer storage and supply module stores a natural polymer mother liquor. The online mixing module is connected to the polymer storage and supply module and a seawater supply mechanism to mix the natural polymer mother liquor with seawater to form a polymer working solution. The inlet end of the high-pressure metering and conveying module is connected to the online mixing module, and the outlet end is connected to the multi-point array injection module to deliver the polymer working solution at a set flow rate. The multi-point array injection module is installed around the body of the deep-sea mining vehicle to spray the polymer working solution into the sediment plume source area. The active control unit is communicatively connected to the main control system of the deep-sea mining vehicle and controls the preparation, conveying, and injection of the polymer working solution according to the operating status of the deep-sea mining vehicle.

[0005] Preferably, the polymer storage and supply module includes at least one pressure-resistant storage tank, which is located inside the body of the deep-sea mining vehicle and is connected to the online mixing module via a flow regulating valve.

[0006] Preferably, the natural polymer mother liquor includes an okra polysaccharide compound solution, which is a compound solution of okra polysaccharide and alginate, or a compound solution of okra polysaccharide and carrageenan; the mass concentration of the natural polymer mother liquor is 0.1wt% to 2.0wt%, and the mass ratio of okra polysaccharide to alginate or carrageenan is 1:0.1 to 1:2.

[0007] Preferably, the online mixing module includes an online mixing chamber and a stirring mechanism disposed within the online mixing chamber. The online mixing chamber is connected to a seawater supply mechanism, a polymer storage and supply module, and a high-pressure metering and conveying module, and is used to dilute the natural polymer mother liquor by 5 to 200 times to form a polymer working solution with a mass concentration of 10 to 1000 mg / L.

[0008] Preferably, the seawater supply mechanism includes a seawater input pipe, a seawater filtration mechanism, and a suction pump, with the inlet end of the seawater input pipe facing the front side of the deep-sea mining vehicle's travel direction.

[0009] Preferably, the high-pressure metering and delivery module includes a metering pump, a metering valve, and a high-pressure resistant delivery main pipeline. The metering pump is used to provide a delivery pressure differential higher than the deep-sea environment pressure, the metering valve is used to regulate the delivery flow rate of the polymer working solution, and the high-pressure resistant delivery main pipeline is arranged inside the body of the deep-sea mining vehicle and is connected to the multi-point array injection module.

[0010] Preferably, the multi-point array jet module includes multiple underwater vortex dispersion nozzles, which are respectively arranged on the left and right sides and the rear of the deep-sea mining vehicle, and respectively facing the lateral plume source area and the rear plume source area.

[0011] Preferably, the underwater vortex dispersion nozzle has multiple inlet vortex channels inside, so that the polymer working solution forms a rotating flow before being sprayed and forms a rotating jet underwater; the spray angle of the underwater vortex dispersion nozzle is 15° to 60° relative to the seabed surface, and the pressure difference between the nozzle inlet pressure and the ambient pressure is 0.1 to 2.0 MPa.

[0012] The second aspect of this invention proposes an active method for suppressing sediment plumes in deep-sea mining, employing the active sediment plume suppression system for deep-sea mining as described in the first aspect, and including the following steps: when the deep-sea mining vehicle starts mining operations, the active control unit receives an operation start signal and initiates the preparation and delivery of a polymer working solution; natural polymer mother liquor is mixed with seawater in an online mixing module to form a polymer working solution; the polymer working solution is delivered to a multi-point array spray module through a high-pressure metering and delivery module, and sprayed into the sediment plume source area through an underwater vortex dispersion nozzle; the polymer working solution contacts sediment particles and causes flocculation to form flocs with increased particle size; when the deep-sea mining vehicle stops mining operations, the active control unit shuts off the delivery and spraying of the polymer working solution.

[0013] Preferably, the active control unit adjusts the injection volume and injection point of the polymer working solution, as well as the activation and deactivation of the underwater vortex dispersion nozzles on the left and right sides and the tail, based on the deep-sea mining vehicle's travel speed, the working status of the sampling head, the discharge flow rate, the track travel power, and / or the plume turbidity. When the sampling head's working status is enhanced, the discharge flow rate increases, or the plume turbidity is higher than a preset threshold, the injection flow rate in the corresponding area is increased or the underwater vortex dispersion nozzles in the corresponding area are activated. When the deep-sea mining vehicle turns or the lateral plume intensifies, the underwater vortex dispersion nozzles on the outside of the turn or the side with higher turbidity are activated first.

[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) The system designed in this invention can be integrated with a deep-sea mining vehicle to release the polymer working solution to the source area of ​​the plume in the early stage of plume formation; the polymer working solution can promote the aggregation of fine sediment particles to form larger particle size flocs, which is beneficial to improving near-field sedimentation efficiency; each module is coordinated with the mining vehicle's operating status to reduce ineffective release and improve the synchronization of system operation; the pressure-resistant storage, online mixing, metering and conveying and array spraying modules are combined to adapt to the high pressure and space-constrained operating environment in the deep sea; (2) The unique design uses okra polysaccharide compound solution jet instead of pure seawater jet, which can reduce jet transport resistance by utilizing its shear thinning properties. At the same time, it forms an efficient capture microenvironment in the plume source area through bridging flocculation, ion cross-linking and delayed gelation mechanisms, thereby improving the flocculation efficiency and near-field settling rate of fine sediment particles (particle size 5-100 μm), and thus inhibiting the diffusion range of sediment plume. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the following description is only one embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the overall structure of an active sediment plume suppression system for deep-sea mining according to the present invention.

[0017] Figure 2 This is a schematic diagram of the nozzle arrangement in an active sediment plume suppression system for deep-sea mining according to the present invention.

[0018] Figure 3 This is a schematic diagram of the structure of the vortex atomizing nozzle in this invention.

[0019] Figure 4 This is a schematic flowchart of an active method for suppressing sediment plumes in deep-sea mining according to the present invention.

[0020] Figure 5 This is a schematic diagram illustrating the polymer rheology-electric field coupling relationship in this invention and its influence on polymer velocity, chain conformation recovery, and degradation processes.

[0021] In the diagram: 101. Ore storage tank; 102. Tracked walking unit; 103. Collection head; 2. Online mixing chamber; 21. Stirring mechanism; 31. Metering pump valve assembly; 32. High-pressure resistant main pipeline; 41. Seawater input pipe; 42. Seawater filtration mechanism; 43. Suction pump; 51. First pressure-resistant storage tank; 52. First metering regulating valve; 53. First pipeline; 61. Second pressure-resistant storage tank; 62. Second metering regulating valve; 63. Second pipeline; 71. Underwater vortex dispersion nozzle. Detailed Implementation

[0022] The present invention will be further described below with reference to embodiments. 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.

[0023] like Figures 1 to 3 As shown, this embodiment provides an active sediment plume suppression system for deep-sea mining. This system is installed as a modular integrated unit on a tracked deep-sea mining vehicle. The deep-sea mining vehicle includes an ore storage tank 101, a tracked walking unit 102, and a collection head 103. Disturbed sediments generated during the movement and collection process of the mining vehicle diffuse with the near-bottom water, forming a sediment plume.

[0024] This system includes a polymer storage and supply module, an online mixing module, a high-pressure metering and conveying module, a multi-point array injection module, and an active control unit 8. The active control unit 8 is communicatively connected to the main control system of the deep-sea mining vehicle, and can receive signals such as the mining vehicle's travel speed, the working status of the sampling head, the discharge flow rate, the track walking power, and / or the plume turbidity, and control the various actuators of the system accordingly.

[0025] The polymer storage and supply module includes a first pressure-resistant storage tank 51 and a second pressure-resistant storage tank 61. The first pressure-resistant storage tank 51 and the second pressure-resistant storage tank 61 are located inside the mining vehicle body and are used to store natural high-molecular polymer mother liquor. The first pressure-resistant storage tank 51 is connected to the online mixing chamber 2 via a first metering regulating valve 52 and a first pipeline 53, and the second pressure-resistant storage tank 61 is connected to the online mixing chamber 2 via a second metering regulating valve 62 and a second pipeline 63.

[0026] In one embodiment, the natural polymer mother liquor can be a compound solution of okra polysaccharide and alginate, or a compound solution of okra polysaccharide and carrageenan. The mass concentration of the mother liquor can be 0.1wt% to 2.0wt%, and the mass ratio of okra polysaccharide to alginate or carrageenan can be 1:0.1 to 1:2; the online dilution factor can be 5 to 200 times, so that the mass concentration of the polymer working solution is in the range of 10 to 1000 mg / L. The above-mentioned compound solution is used to generate adsorption bridging, particle aggregation, and floc growth after contacting sediment particles.

[0027] Figure 5 This is a schematic diagram of the polymer rheological-electric field coupling relationship, used to characterize different β values. With Wi conditions E k / E k0 The variation law is used to explain the velocity regulation mechanism of the polymer working solution during nozzle delivery, plume capture, and subsequent degradation stages. Where Ek is the fluid kinetic energy flux (dimensionless kinetic energy) under the current operating conditions, and E... k0 For reference kinetic energy, E k / E k0 is the kinetic energy decay ratio (dimensionless kinetic energy retention rate); Wi is the Weissenberg number.

[0028] Using okra polysaccharide compound solution jet instead of pure seawater jet can reduce jet transport resistance by utilizing its shear thinning properties. At the same time, it forms an efficient capture microenvironment in the source region of the plume through bridging flocculation, ion cross-linking and delayed gelation mechanisms, thereby improving the flocculation efficiency and near-field settling rate of fine sediment particles (5-100 μm in diameter) and thus inhibiting the diffusion range of sediment plume.

[0029] When the compound solution enters the sediment plume region, the flow velocity decreases and the shear rate drops sharply. <100 s -1 The molecular chains recover from their oriented state to a random coiled conformation, and the viscosity rapidly rises to a high value. At this point, the polymer chains of okra polysaccharides and alginate adsorb multiple sediment particles through a bridging mechanism; simultaneously, Ca in seawater... 2+ and Mg 2+ It can combine with guluronic acid units in the alginate molecular chain to form a cross-linked structure, transforming the compound solution from a low-viscosity state during the transport stage to a high-viscosity, strongly adsorbed state during the plume capture stage. This decrease in velocity and increase in residence time facilitates conformational rearrangement, shearing, or hydrolytic degradation of the polymer chains, allowing the polymer to degrade more rapidly after flocculation and capture, thereby reducing the risk of long-term residue.

[0030] in, And β are shown in the following equations. In equation (1), Here, is the electric field strength parameter, used to characterize the coupling strength between ion concentration, characteristic length, and reference electric field; e is the unit charge. Where is the equilibrium ion concentration or reference ion concentration, d is the characteristic length of the injection section, ε is the dielectric constant of the medium, and E0 is the reference electric field strength. In equation (2), β is the height scale parameter, used to characterize the effective height scale of the charge layer or confined flow region under the action of the external field; O is a dimensionless correction parameter related to the thickness of the charge layer or the confined flow region. Let K be the characteristic charge density, and K be the charge migration or diffusion correlation coefficient. B π is Boltzmann's constant, T is the absolute temperature, and π is pi. Figure 5 The curve showing the E / E0 versus Wi indicates that, in β and When the value is small, the electric field strength decays more slowly; at β and As Wi increases, E / E0 decreases significantly or exhibits non-monotonic fluctuations, indicating that the coupling between polymer elasticity, conformation tensor, and electric field force is enhanced, which can improve local stress dissipation and reduce the effective velocity of the polymer working solution after spraying.

[0031] (1) (2) The dimensionless form of the above equation is shown below. In equation (3), t* is the dimensionless time, u* is the dimensionless velocity vector, and p* is the dimensionless pressure. For gradient operators, ² represents the Laplace operator, C is the polymer conformation tensor, used to characterize the extension and orientation states of polymer chains; Wi is the Weissenberg number. χ is the characteristic Reynolds number of the electric field, χ is the solvent viscosity percentage, and M is the dimensionless electromigration parameter. and are dimensionless quantities representing the concentrations of positive and negative ions, respectively, and E* is the dimensionless electric field strength. In equation (3), the left side represents the dimensionless inertial and convection terms, while the right side includes the pressure, viscosity, polymer conformational stress, and electric force terms, respectively. In equation (4), ·u*=0 indicates that the polymer working solution satisfies the incompressible continuity condition.

[0032] (3) (4) To further describe the velocity variation, stress transmission, and external field coupling of the polymer working solution in the spray section, this embodiment can use the Navier-Stokes equations containing polymer stress terms and electric field force terms, as shown in equation (5). In equation (5), ρ m Let ρ be the density of the mixed fluid, t be time, u be the velocity vector, p be the pressure, and η be the pressure. s ρ is the solvent viscosity, D is the deformation rate tensor, and τ is the polymer stress tensor, used to characterize the contribution of polymer chain extension, orientation, and relaxation to fluid momentum transfer; E Let ρ be the charge density, E be the electric field strength, and ρ be the electric field strength. E E represents the electric force term. In equation (6), •u=0 indicates that the polymer working solution satisfies the incompressible flow condition.

[0033] (5) (6) Based on the polymer solution flow mechanism, during high-speed jetting, the long-chain molecules of okra polysaccharide and alginate align along the flow direction, reducing inter-chain entanglement and resulting in a significant decrease in effective viscosity. For power-law fluids, the jet outlet velocity... This can be expressed by the modified Bernoulli equation: , where ΔP is the pressure difference before and after the nozzle, and ρ is the solution density. Since n<1, the compound solution has the characteristics of low resistance and high fluidity during the nozzle delivery stage, which can improve the jet coverage distance and enhance the contact with the plume source area.

[0034] In deep-sea mining environments (pressure 40-60 MPa, temperature 0-4°C), okra polysaccharide and alginate complex solutions exhibit unique non-Newtonian rheological properties. Rheological studies of okra polysaccharide show that aqueous solutions exhibit significant pseudoplastic shear-thinning behavior, with viscosity decreasing with increasing shear rate. This behavior can be described by the Ostwald-DeWaele power-law model: τ = K· n, where τ is the shear stress and K is the consistency coefficient. Let n be the shear rate and n be the flow index. For okra polysaccharide compound solutions, n can be 0.2-0.6, and n<1 characterizes the shear-thinning properties; under high shear conditions passing through a nozzle ( >1000 s -1 The apparent viscosity of the compound solution can be reduced to 30%-50% of the static viscosity, thereby reducing the flow resistance in pipelines and nozzles.

[0035] The online mixing module includes an online mixing chamber 2 and a stirring mechanism 21. The online mixing chamber 2 is located inside the ore storage tank 101 or in the installation space inside the vehicle body. The stirring mechanism 21 is located inside the online mixing chamber 2 and is used to mix the seawater and natural polymer mother liquor entering the online mixing chamber 2.

[0036] The seawater supply mechanism includes a seawater inlet pipe 41, a seawater filtration mechanism 42, and a suction pump 43. The inlet end of the seawater inlet pipe 41 faces the front of the mining vehicle in the direction of travel, and the other end is connected to the online mixing chamber 2 via the seawater filtration mechanism 42. The suction pump 43 is used to supply seawater to the online mixing chamber 2.

[0037] The high-pressure metering and delivery module includes a metering pump, a metering valve, and a high-pressure resistant delivery main pipeline 32. The metering pump and metering valve can be integrated into a metering pump-valve assembly 31. The inlet end of the high-pressure resistant delivery main pipeline 32 is connected to the online mixing chamber 2, and the outlet end is connected to the multi-point array injection module. The metering pump-valve assembly 31 is communicatively connected to the active control unit 8 to provide a delivery pressure differential higher than the deep-sea environment pressure and regulate the delivery flow rate of the polymer working solution.

[0038] The multi-point array spraying module includes multiple underwater vortex dispersion nozzles 71. These nozzles 71 can be arranged on the left and right sides and rear of the mining vehicle to spray the polymer working solution into the lateral and rearward plume source areas. Each underwater vortex dispersion nozzle 71 can be controlled independently or in conjunction with other nozzles to adapt to different plume distributions under different mining vehicle operating conditions.

[0039] like Figure 3 As shown, the underwater vortex dispersion nozzle 71 has multiple inlet vortex channels inside. After the polymer working solution enters the nozzle, it forms a rotating flow and a rotating jet underwater. The term "dispersion" refers to expanding the mixing contact area and coverage in a deep-sea liquid environment, not droplet atomization in an air environment.

[0040] In one specific embodiment, the total flow rate of the polymer working solution can be 0.5–20 L / min, the pressure difference between the inlet pressure of a single underwater vortex dispersion nozzle 71 and the ambient pressure can be 0.1–2.0 MPa, and the spray angle relative to the seabed surface can be 15°–60°, suitable for fine-particle sediment plumes with a median particle size D50 of 5–100 μm. The above ranges can be adjusted according to the size of the mining vehicle, its travel speed, the power of the sampling head, and the turbidity of the plume.

[0041] like Figure 4 As shown, the active method for suppressing sediment plumes of the present invention includes the following steps: when the deep-sea mining vehicle starts mining operations, the active control unit 8 receives the operation start signal and starts the preparation and delivery of the polymer working solution; the natural high-molecular polymer mother liquor in the first pressure-resistant storage tank 51 and the second pressure-resistant storage tank 61 enters the online mixing chamber 2 and mixes with the seawater supplied by the seawater supply mechanism; the high-pressure metering and delivery module delivers the formed polymer working solution to the underwater vortex dispersion nozzle 71; the underwater vortex dispersion nozzle 71 sprays the polymer working solution to the sediment plume source area; after the polymer working solution comes into contact with the sediment particles, it forms flocs and promotes sedimentation; when the mining vehicle stops operating, the active control unit 8 shuts off the delivery and spraying of the polymer working solution.

[0042] The active control unit 8 can adjust the injection strategy according to the mining vehicle's travel speed, the working status of the sampling head, the emission flow rate, the track travel power, and / or the plume turbidity. When the sampling head power increases, the emission flow rate increases, or the plume turbidity is higher than a preset threshold, the active control unit 8 increases the injection flow rate of the corresponding area by 10% to 50% or opens the underwater vortex dispersion nozzle 71 of the corresponding area; when the mining vehicle turns or the lateral plume intensifies, the active control unit 8 prioritizes opening the underwater vortex dispersion nozzle 71 on the outside of the turn or the side with higher turbidity; when the working status decreases or the turbidity returns to below the threshold, the active control unit 8 reduces the injection flow rate or closes some nozzles to reduce ineffective release.

[0043] In one specific embodiment, the number of underwater vortex dispersion nozzles 71 is nine, with three on each side and three at the tail. The above number and arrangement are only an example, and can be adjusted according to the size of the mining vehicle, the plume emission area, the travel speed, and the sampling conditions in actual applications.

[0044] In one specific embodiment, the stirring mechanism 21 can be a spiral stirring paddle, equipped with a deep-sea sealed drive motor; the pressure-resistant storage tank can be a titanium alloy pressure-resistant tank; and the high-pressure resistant main pipeline 32 can be a pressure-resistant pipeline suitable for the high-pressure environment of deep sea. The above materials, specifications, and parameters can be selected according to the actual operating water depth and the structure of the mining vehicle.

[0045] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

[0046] While the specific embodiments of the present invention have been described above, they are not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. An active sediment plume suppression system for deep-sea mining, characterized in that: The system is integrated onto a deep-sea mining vehicle and includes a polymer storage and supply module, an online mixing module, a high-pressure metering and conveying module, a multi-point array injection module, and an active control unit. The polymer storage and supply module stores natural polymer mother liquor. The online mixing module is connected to the polymer storage and supply module and a seawater supply mechanism to mix the natural polymer mother liquor with seawater to form a working polymer solution. The inlet end of the high-pressure metering and conveying module is connected to the online mixing module, and the outlet end is connected to the multi-point array injection module to deliver the working polymer solution at a set flow rate. The multi-point array injection module is installed around the body of the deep-sea mining vehicle to spray the working polymer solution into the sediment plume source area. The active control unit is communicatively connected to the main control system of the deep-sea mining vehicle, and controls the preparation, delivery and spraying of the polymer working solution according to the operating status of the deep-sea mining vehicle.

2. The active sediment plume suppression system for deep-sea mining according to claim 1, characterized in that: The polymer storage and supply module includes at least one pressure-resistant storage tank, which is located inside the body of the deep-sea mining vehicle and is connected to the online mixing module via a flow regulating valve.

3. The active sediment plume suppression system for deep-sea mining according to claim 1, characterized in that: The natural polymer mother liquor includes an okra polysaccharide compound solution, which is a compound solution of okra polysaccharide and alginate, or a compound solution of okra polysaccharide and carrageenan; the mass concentration of the natural polymer mother liquor is 0.1wt% to 2.0wt%, and the mass ratio of okra polysaccharide to alginate or carrageenan is 1:0.1 to 1:

2.

4. The active sediment plume suppression system for deep-sea mining according to claim 1, characterized in that: The online mixing module includes an online mixing chamber and a stirring mechanism disposed within the online mixing chamber. The online mixing chamber is connected to a seawater supply mechanism, a polymer storage and supply module, and a high-pressure metering and conveying module, and is used to dilute the natural polymer mother liquor by 5 to 200 times to form a polymer working solution with a mass concentration of 10 to 1000 mg / L.

5. The active sediment plume suppression system for deep-sea mining according to claim 1, characterized in that: The seawater supply mechanism includes a seawater input pipe, a seawater filtration mechanism, and a suction pump, with the inlet end of the seawater input pipe facing the front side of the deep-sea mining vehicle's travel direction.

6. The active sediment plume suppression system for deep-sea mining according to claim 1, characterized in that: The high-pressure metering and delivery module includes a metering pump, a metering valve, and a high-pressure resistant delivery main pipeline. The metering pump is used to provide a delivery pressure differential higher than the deep-sea environment pressure. The metering valve is used to regulate the delivery flow rate of the polymer working solution. The high-pressure resistant delivery main pipeline is arranged inside the body of the deep-sea mining vehicle and is connected to the multi-point array injection module.

7. The active sediment plume suppression system for deep-sea mining according to claim 1, characterized in that: The multi-point array jet module includes multiple underwater vortex dispersion nozzles, which are respectively arranged on the left and right sides and the rear of the deep-sea mining vehicle, and respectively facing the lateral plume source area and the rear plume source area.

8. The active sediment plume suppression system for deep-sea mining according to claim 7, characterized in that: The underwater vortex dispersion nozzle is provided with multiple inlet vortex channels to make the polymer working solution form a rotating flow before being sprayed out and form a rotating jet underwater; The underwater vortex dispersion nozzle has a spray angle of 15° to 60° relative to the seabed surface, and a pressure difference of 0.1 to 2.0 MPa between the nozzle inlet pressure and the ambient pressure.

9. A method for actively suppressing sediment plumes in deep-sea mining, characterized in that: The active sediment plume suppression system for deep-sea mining as described in any one of claims 1 to 8 includes the following steps: when the deep-sea mining vehicle starts mining operations, the active control unit receives an operation start signal and initiates the preparation and delivery of a polymer working solution; the natural polymer mother liquor is mixed with seawater in an online mixing module to form a polymer working solution; the polymer working solution is delivered to a multi-point array spray module through a high-pressure metering and delivery module, and sprayed into the sediment plume source area through an underwater vortex dispersion nozzle; the polymer working solution contacts the sediment particles and causes flocculation to form flocs with increased particle size; when the deep-sea mining vehicle stops mining operations, the active control unit shuts off the delivery and spraying of the polymer working solution.

10. A method for actively suppressing sediment plumes in deep-sea mining according to claim 9, characterized in that: The active control unit adjusts the injection volume and injection point of the polymer working solution, as well as the activation and deactivation of the underwater vortex dispersion nozzles on the left and right sides and the tail, based on the deep-sea mining vehicle's travel speed, the working status of the sampling head, the discharge flow rate, the track travel power, and / or the plume turbidity. When the sampling head's working status is enhanced, the discharge flow rate increases, or the plume turbidity is higher than a preset threshold, the injection flow rate of the corresponding area is increased or the underwater vortex dispersion nozzles of the corresponding area are activated. When the deep-sea mining vehicle turns or the lateral plume intensifies, the underwater vortex dispersion nozzles on the outside of the turn or the side with higher turbidity are activated first.

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