Deep sea polymetallic nodule dewatering and drying system and ship thereof

Abstract

The invention discloses a deep sea polymetallic nodule dewatering and drying system which comprises a dewatering module and a drying module. The dehydration module is used for dehydrating free gap moisture of deep sea metal nodules, the dehydration module separates the free gap moisture from the metal nodules in a mechanical vibration and extrusion crushing mode, and residual seepage water of the metal nodules in the storage process is collected and discharged. The deep sea metal nodule integrated treatment process is integrated on the ship, offshore in-situ treatment is achieved, and economic benefits are improved. By combining multiple stages of dehydration equipment, the dehydration efficiency of free pore water of the metal nodule is improved. The dewatered metal nodule is heated and dried by waste heat of the smoke pipe of the ship main engine, capillary water and adsorbed water in the metal nodule are effectively evaporated, the water content of the metal nodule is reduced from 80% to about 10%, and meanwhile the ship energy recycling rate is increased.

Description

Technical Field

[0001] This invention relates to the field of deep-sea mining technology, specifically to a deep-sea polymetallic nodule dehydration and drying system and its vessel. Background Technology

[0002] With the increasing depletion of terrestrial resources, the development of deep-sea resources is receiving more and more attention, and the utilization of deep-sea minerals has become an important way to alleviate the shortage of terrestrial resources. Deep-sea polymetallic nodules are rich in various valuable metals such as manganese, nickel, copper, and cobalt, and have enormous economic value. However, the efficient mining and utilization of seabed metal nodules faces many difficulties.

[0003] First, transportation costs are high. After deep-sea polymetallic nodules are mined, they need to be transported to land for processing. Long-distance sea transport increases transportation costs, and the use of transport vessels also increases carbon emissions. Second, offshore processing technology for metal nodules is immature and limited. Traditional ship-based processing technology only has mechanical coarse crushing and preliminary sorting capabilities, lacking integrated processing systems. The dehydration process relies on single equipment, such as centrifuges to remove free pore water from metal nodules, resulting in low dehydration rates.

[0004] Furthermore, when metal nodules are stored on board after mechanical crushing, separation, and dehydration, the capillary water and adsorbed water in the nodules have a high permeability rate, affecting the ship's stability and safety. Meanwhile, existing ship exhaust gases are directly emitted into the air without effectively utilizing the heat from the exhaust pipes. Summary of the Invention

[0005] The present invention aims to overcome at least one of the defects of the prior art and provide a deep-sea polymetallic nodule dehydration and drying system and its vessel, which enables efficient processing of deep-sea polymetallic nodules on a ship and increases the dehydration rate of various moistures in the metal nodules.

[0006] This invention provides a deep-sea polymetallic nodule dehydration and drying system, including a dehydration module and a drying module; the dehydration module is used to dehydrate the free pore water of the deep-sea metal nodules, and the dehydration module separates the free pore water from the metal nodules through mechanical vibration and crushing, and collects and discharges the seepage water remaining in the metal nodules during the storage process.

[0007] The drying module is used to evaporate and dry the capillary water and adsorbed water in the deep-sea metal nodules after they have been dehydrated by the dehydration module. It mainly uses high-temperature dry air to evaporate the capillary water and adsorbed water in the metal nodules.

[0008] The drying module includes a flue waste heat recovery unit, a hot water heater, a fan, and a drying chamber;

[0009] The waste heat recovery unit uses the waste heat from the main unit's flue to heat the heat transfer medium, fresh water. The heated fresh water then enters the hot water heater and exchanges heat with the air supplied by the fan. The hot water heater is used for heat exchange between the heat transfer medium, fresh water, and air. Afterward, the hot air is transported to the drying room to heat, ventilate, and dry the nodules.

[0010] The fan is used to deliver air to the hot water heater for heat exchange, and then deliver the heated air to the drying room.

[0011] The drying chamber heats, purifies, and dries the metal nodules that are conveyed to the drying chamber by a conveying device with hot air supplied by a fan. The treated hot air is then discharged into the atmosphere.

[0012] Furthermore, the drying module also includes an expansion tube, an expansion tank, and a freshwater circulation pump. One end of the expansion tube is connected to the expansion tank, and the other end is connected to the circulation pump. The expansion tube is used to collect the steam generated after the freshwater is heated by the flue gas waste heat recovery device and lead it to the expansion tank for cooling and recycling. The freshwater circulation pump is used to provide power to the heat transfer medium freshwater and to pressurize the system return water and the makeup water from the expansion tank.

[0013] Furthermore, the expansion tank is equipped with a chemical dosing port to prevent scale formation.

[0014] The expansion tube collects the steam generated after the heat transfer medium is heated by the flue gas waste heat recovery unit and leads it to the expansion tank. One end of the expansion tube is connected to the expansion tank, and the other end is connected to the heat transfer medium circulation system. The expansion tank replenishes the heat transfer medium to the freshwater circulation pump and separates air to prevent air blockage. Simultaneously, the expansion tank provides a chemical dosing interface to prevent scale formation. The freshwater circulation pump provides power to the heat transfer medium and pressurizes the system's return and makeup water.

[0015] Furthermore, the heat transfer medium, fresh water, in the hot water heater exchanges heat with air to generate hot air at a temperature of 60-80℃.

[0016] Furthermore, the dewatering module includes a vibrating screen, a hydrocyclone separator, a screw extruder, a centrifugal settler, a filter press, a conveying device, a mineral storage tank, a seepage discharge pump, a treated water storage tank, and a treated water discharge pump. The vibrating screen is used for the initial separation of large metal nodules and impurities from polymetallic nodules. The hydrocyclone separator performs hydrocyclone concentration and classification on the metal nodules separated from the vibrating screen, separating the metal nodule particles through centrifugal force. The screw extruder crushes and dewaters the metal nodules separated by the vibrating screen and the hydrocyclone separator. The centrifugal settler recovers the fine metal nodules from the hydrocyclone separator and the screw extruder, forming sludge, wherein the sludge enters... The seawater is fed into a filter press, and the separated seawater is discharged into a treated water storage tank. The conveying device transports the dehydrated metal nodules from the screw press and filter press to a drying room for drying. The dried metal nodules are then transported to a mineral storage tank for storage. The mineral storage tank is used to store the dehydrated and dried metal nodules. The seepage discharge pump is used to pump the seepage from each mineral storage tank to the treated water storage tank. The treated water storage tank is used to store the seawater extracted and transported along with the metal nodules, as well as the dehydrated metal nodules. After settling and treatment of insoluble floating matter, the treated water can be discharged into the sea. The treated water discharge pump is used to discharge the treated water from the treated water storage tank back into the deep sea.

[0017] Furthermore, the hydrocyclone separator is used to separate metal nodule particles with a diameter greater than 0.5 mm. The separated metal nodule particles enter the screw extruder, while metal nodule particles with a diameter less than 0.5 mm and seawater are separated and enter the hydrocyclone separator.

[0018] Preferably, the mineral storage chamber is funnel-shaped.

[0019] The present invention also provides a vessel for mining deep-sea polymetallic nodules, including the aforementioned deep-sea polymetallic nodule dehydration and drying system.

[0020] The deep-sea polymetallic nodule dehydration and drying system of this invention avoids long-distance transportation of metal nodules with excessive water content, reducing transportation costs and carbon emissions. It fully utilizes the waste heat from the ship's main engine exhaust pipes to dry the metal nodules, evaporating capillary water and adsorbed water inside the nodules. This prevents excessive water seepage in the storage tanks, which could lead to changes in the nodule stack and alter the ship's center of gravity.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] This invention integrates the deep-sea metal nodule processing process onto a ship, enabling in-situ treatment at sea and improving economic efficiency. It utilizes a combination of multi-stage dewatering equipment, such as vibrating screens, hydrocyclones, screw presses, centrifugal settling tanks, and filter presses, to achieve highly efficient dewatering and improve the dewatering efficiency of free pore water in the metal nodules. The waste heat from the ship's main engine exhaust pipes is used to heat and dry the dewatered metal nodules, effectively evaporating capillary water and adsorbed water inside the nodules, reducing the water content of the metal nodules from 80% to approximately 10%, while simultaneously improving the ship's energy recycling rate. This invention integrates the metal nodule dewatering and drying modules into a single system, achieving automated and continuous operation, improving processing efficiency, and reducing manual operation costs. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall device position of the present invention.

[0024] Figure 2 This is a system diagram of the present invention.

[0025] The attached diagram is labeled as follows:

[0026] 01. Dewatering module; 02. Drying module; 0101. Vibrating screen; 0102. Hydrocyclone separator; 0103. Screw extruder; 0104. Centrifugal sedimentation tank; 0105. Filter press; 0106. Conveying device; 0107. Mineral storage tank; 0108. Leakage discharge pump; 0109. Treated water storage tank; 0110. Treated water discharge pump; 0201. Flue waste heat recovery unit; 0202. Hot water heater; 0203. Fan; 0204. Drying room; 0205. Expansion pipe; 0206. Expansion tank; 0207. Fresh water circulation pump. Detailed Implementation

[0027] The accompanying drawings illustrate the technical solutions of the embodiments of the present invention in more detail. Throughout the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The described embodiments are some, but not all, embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Example

[0028] like Figure 1-2As shown, the present invention provides a deep-sea polymetallic nodule dehydration and drying system for ships, which reduces the moisture content of the dehydrated and dried metal nodules to about 10%. The system includes a dehydration module 01 and a drying module 02.

[0029] The dehydration module 01 is used for dehydrating the free pore water of deep-sea metal nodules and includes the following dehydration devices: a vibrating screen 0101, a hydrocyclone separator 0102, a screw press 0103, a centrifugal sedimentation tank 0104, a filter press 0105, a conveying device 0106, a mineral storage tank 0107, a seepage discharge pump 0108, a treated water storage tank 0109, and a treated water discharge pump 0110. The vibrating screen 0101 contains a filter screen, and the vibration transmitted by the motor is used to initially separate large metal nodules and impurities in the polymetallic nodules. The filter screen filters out metal nodules with a diameter greater than 5mm. The separated metal nodules enter the screw press 0103, while metal nodules with a diameter less than 5mm and seawater are separated and enter the hydrocyclone separator. The cyclone separator 0102 performs cyclone concentration and classification on the metal nodules separated from the vibrating screen 0101, separating metal nodule particles with a diameter greater than 0.5 mm through centrifugal force. The separated metal nodule particles enter the screw extruder 0103, while metal nodule particles with a diameter less than 0.5 mm and seawater are discharged through the overflow port to the centrifugal settling tank 0104. The screw extruder 0103 crushes and dehydrates the metal nodules separated from the vibrating screen 0101 and the cyclone separator 0102. The separated water and fine metal nodules are discharged through the drain port of the equipment to the centrifugal settling tank 0104, while the crushed metal nodules are discharged from the discharge port of the equipment and enter the transfer device 0106.

[0030] The centrifugal settler 0104 recovers fine metal nodules from the hydrocyclone separator 0102 and the screw extruder 0103. Centrifugal force causes mineral powder with a diameter greater than 0.01 mm to settle onto the drum wall, forming sludge. The sludge enters the filter press 0105, and the separated seawater is discharged into the treated water storage tank 0109. The filter press 0105 uses a pressing mechanism to discharge the filtrate through the filter cloth. The filter cloth inside the filter frame is used to block the metal nodule mineral powder. After the filter plates and filter frames are loosened, the dehydrated metal nodule mineral powder automatically falls to the conveying device 0106 for separation. The filtrate enters the treated water storage tank 0109; the conveying device 0106 conveys the dehydrated metal nodules from the screw press 0103 and filter press 0105 to the drying room 0204 for drying, and the dried metal nodules are conveyed to the mineral storage chamber 0107 for storage by the conveying device 0106; the mineral storage chamber 0107 is used to store the dehydrated and dried metal nodules. When the metal minerals are stacked, the mutual compression and the change in pressure inside and outside the metal nodules after long-term stacking still cause a small amount of water to seep out. The mineral storage chamber 0107 is made into a funnel shape to facilitate the collection of seepage water.

[0031] The seepage discharge pump 0108 is used to pump the seepage from each metal nodule storage tank to the treated water storage tank 0109; the treated water storage tank 0109 is used to store seawater extracted and transported along with the metal nodules, as well as the dehydrated metal nodules. The treated water after settling and treatment of insoluble floating matter can be discharged into the sea; the treated water discharge pump 0110 is used to discharge the treated water from the treated water storage tank 0109 back into the deep sea; the drying module 02 is used for the evaporation of capillary water and adsorbed water from the deep-sea metal nodules. It uses the waste heat from the ship's main engine exhaust pipe to treat the metal nodules after dehydration of free pore water, and uses heated air to heat, ventilate, and dry the nodules, thereby reducing the seepage rate and the resulting ship stability risks during the subsequent metal nodule storage stage. The drying module 02 includes a flue waste heat recovery unit 0201, a hot water heater 0202, a fan 0203, a drying chamber 0204, an expansion tube 0205, an expansion tank 0206, and a freshwater circulation pump 0207. The flue waste heat recovery unit 0201 uses the waste heat from the main unit's flue to heat the heat transfer medium, freshwater, to 70-90℃. The exhaust gas from the main unit after heat transfer is discharged into the air. The heated heat transfer medium, freshwater, enters the hot water heater 0202 and exchanges heat with the air supplied by the fan 0203. The hot water heater 0202 is used for the exchange of heat transfer medium freshwater and air. Heat exchange is performed to generate hot air at 60-80°C. The hot air is then transported to the drying chamber 0204 to heat, ventilate, and dry the nodules. The fan 0203 is used to transport air to the hot water heater 0202 for heat exchange and to transport the heated air to the drying chamber 0204. The drying chamber 0204 is the last processing step before the nodules are transported to the storage chamber. The hot air from the fan 0203 heats, purifies, and dries the metal nodules that are transported to the drying chamber 0204 via the conveying device 0104. The treated hot air is then discharged into the atmosphere.

[0032] The expansion pipe 0205 is used to collect the steam generated after the fresh water is heated by the flue gas waste heat recovery unit 0201 and leads it to the expansion tank 0206 for cooling and recycling. One end of the expansion pipe 0205 is connected to the expansion tank 0206, and the other end is connected to the fresh water circulation system. The expansion pipe 0205 transfers the increased volume due to heating expansion to the expansion tank 0206. The expansion tank 0206 is used to replenish water to the fresh water circulation pump 0207, maintain stable system pressure, and avoid pressure fluctuations caused by thermal expansion and contraction. The expansion tank 0206 separates air in the fresh water system to prevent air blockage. The expansion tank 0206 provides a chemical dosing interface to prevent scale formation. The fresh water circulation pump 0207 is used to provide power to the heat transfer medium, fresh water, and to pressurize the system return water and the replenishment water from the expansion tank 0206.

[0033] The above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the preferred embodiments above, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention should not depart from the spirit and scope of the present invention. Those skilled in the art can also make other changes within the spirit of the present invention and use them in the design of the present invention, as long as they do not deviate from the technical effects of the present invention. These changes made according to the spirit of the present invention should all be included within the scope of protection claimed by the present invention.

Claims

1. A deep-sea polymetallic nodule dehydration and drying system, characterized in that, It includes a dehydration module (01) and a drying module (02); the dehydration module (01) is used to dehydrate the free pore water in deep-sea metal nodules; the drying module (02) is used to evaporate and dry the capillary water and adsorbed water in the deep-sea metal nodules after dehydration by the dehydration module (01); the drying module (02) includes a flue waste heat recovery unit (0201), a hot water heater (0203) (0202), a fan (0203), and a drying room (0204); The waste heat recovery unit (0201) uses the waste heat from the main unit's flue to heat the heat transfer medium, fresh water. The heated fresh water then enters the hot water heater (0203)(0202) and exchanges heat with the air supplied by the fan (0203). The hot water heater (0203)(0202) is used for heat exchange between the heat transfer medium, fresh water, and air. Afterward, the hot air is transported to the drying room (0204) to heat, ventilate, and dry the nodules. The fan (0203) is used to transport air to the hot water heater (0203)(0202) for heat exchange, and to transport the heated air to the drying room (0204); The drying chamber (0204) heats, purifies, and dries the metal nodules that are conveyed to the drying chamber (0204) by hot air from the fan (0203) via the conveying device (0106), and then discharges the treated hot air into the atmosphere.

2. The deep-sea polymetallic nodule dehydration and drying system according to claim 1, characterized in that, The drying module (02) also includes an expansion pipe (0205), an expansion tank (0206), and a freshwater circulation pump (0207). One end of the expansion pipe (0205) is connected to the expansion tank (0206), and the other end is connected to the circulation pump. The expansion pipe (0205) is used to collect the steam generated after the freshwater is heated by the flue gas waste heat recovery unit (0201) and lead it to the expansion tank (0206) for cooling and recycling. The freshwater circulation pump (0207) is used to provide power to the heat transfer medium freshwater and to pressurize the system return water and the makeup water from the expansion tank (0206).

3. The deep-sea polymetallic nodule dehydration and drying system according to claim 2, characterized in that, The expansion tank (0206) is equipped with a dosing port.

4. The deep-sea polymetallic nodule dehydration and drying system according to claim 1, characterized in that, The hot water heater (0203) and (0202) exchange heat between the heat transfer medium fresh water and air to generate hot air at a temperature of 60-80℃.

5. The deep-sea polymetallic nodule dehydration and drying system according to claim 2, characterized in that, The dewatering module (01) includes a vibrating screen (0101), a hydrocyclone separator (0102), a screw extruder (0103), a centrifugal sedimentation tank (0104), a filter press (0105), a conveying device (0106), a mineral storage tank (0107), a seepage discharge pump (0108), a treated water storage tank (0109), and a treated water discharge pump (0110); The vibrating screen (0101) is used for the preliminary separation of large metal nodules and impurities in polymetallic nodules; The hydrocyclone separator (0102) performs hydrocyclone concentration and classification on the metal nodules separated from the vibrating screen (0101), and separates the metal nodule mineral particles by centrifugal force; The screw extruder (0103) crushes and dehydrates the metal nodules separated by the vibrating screen (0101) and the hydrocyclone separator (0102). The centrifugal settling tank (0104) recovers fine metal nodules from the hydrocyclone separator (0102) and the screw press (0103) to form sludge, which enters the filter press (0105). The separated seawater is discharged into the treated water storage tank (0109). The conveying device (0106) conveys the dewatered metal nodules from the screw press (0103) and the filter press (0105) to the drying room (0204) for drying. The dried metal nodules are then conveyed to the mineral storage tank (0107) for storage via the conveying device (0106). The mineral storage compartment (0107) is used to store dehydrated and dried metal nodules; The seepage discharge pump (0108) is used to pump the seepage from each mineral storage tank (0107) to the treated water storage tank (0109); the treated water storage tank (0109) is used to store the seawater transported up with the metal nodules and the dehydrated metal nodules. The treated water after settling and treatment of insoluble floating matter can be discharged into the sea. The treated water discharge pump (0110) is used to discharge the treated water in the treated water storage tank (0109) back to the deep sea.

6. The deep-sea polymetallic nodule dehydration and drying system according to claim 5, characterized in that, The hydrocyclone separator (0102) is used to separate metal nodule mineral particles with a diameter greater than 0.5 mm. The separated metal nodule mineral particles enter the screw extruder (0103). Metal nodule mineral particles with a diameter less than 0.5 mm and seawater are separated and enter the hydrocyclone separator (0102).

7. The deep-sea polymetallic nodule dehydration and drying system according to claim 5, characterized in that, The mineral storage compartment (0107) is funnel-shaped.

8. A vessel for mining deep-sea polymetallic nodules, characterized in that, The system includes the deep-sea polymetallic nodule dehydration and drying system according to any one of claims 1 to 7.

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