Primary-secondary floating net device for mariculture and construction method thereof

Abstract

The invention relates to a mother-son floating net device for mariculture, and mainly relates to the field of marine floating net culture. The device comprises a son net cage unit (1), a mother net cage unit (2), a son net cage connecting rope system (3), a mother net cage cable-stayed rope (4) and a bottom anchor chain system (5). The sub net cage purse net (12) is a semi-closed structure purse net with an opening and a bottom net sheet; the mother net cage mesh (22) is of a one-circle mesh or multi-circle parallel structure without bottom and top meshes on the whole. The child-mother net cage structure can effectively block the environmental water speed. In addition, the invention further provides an offshore construction method of the device, which comprises the following steps of: (1) driving the anchor pile (53) through Beidou satellite positioning; (2) laying a bottom anchor chain system (5) on the seabed; (3) connecting the sub net cage units (1) by using ropes; (4) the multiple sections of mother net cage units (2) are welded into a whole; (5) connecting each peripheral sub net cage 1 to the mother net cage unit (2) through a rope; and (6) the mother net cage unit (2) is connected with a bottom annular anchor chain (51) through a rope.

Description

Technical Field

[0001] This invention relates to a floating net device for marine aquaculture and its construction method, mainly relating to the field of marine floating net aquaculture. Background Technology

[0002] Floating net aquaculture is a method of raising fish in marine environments by using enclosed net cages that float on the sea, forming a semi-enclosed enclosure with an open top. Currently, the technologies used in floating net aquaculture include floating frames, nets, net weights, and anchor chains, anchor piles, and guy ropes to secure the entire structure.

[0003] Due to the variable marine environment, especially in the deep sea far from land, water currents often exceed 1 meter per second due to wind, waves, and tides. For farmed organisms such as large yellow croaker, excessively high water current velocities within net cages negatively impact their normal growth. When the current is too fast, farmed organisms like large yellow croaker need to continuously wiggle their tail and pectoral fins to maintain a stable position in the water, leading to a significant increase in oxygen consumption. Excessive current also forces the fish to rub frequently against the net cages, causing the shedding of mucus from their bodies and increasing the probability of bacterial infection. Prolonged exposure to currents exceeding 1 meter per second causes large yellow croaker to secrete stress hormones (such as cortisol), leading to elevated blood sugar, decreased immunity, and reduced immune indicators such as lysozyme activity and superoxide dismutase (SOD) activity in the blood, significantly weakening their resistance to environmental fluctuations (such as changes in temperature and salinity). Current velocity is a key environmental factor affecting the feeding behavior of farmed organisms like large yellow croaker; current velocities exceeding 1 meter per second directly interfere with the feeding process, thus affecting growth.

[0004] Furthermore, high water flow velocity is detrimental to the overwintering of farmed organisms such as large yellow croaker. In winter, these organisms experience lower activity, slower metabolism, and are less vigorous than in summer. It is difficult to farm large yellow croaker when the tidal current velocity exceeds 0.8 m / s. Existing technologies often employ floating net systems composed of multiple combined arrays of net cages, but the outer net cages still face the problem of excessively high water velocities. Summary of the Invention

[0005] To address the problem of excessively high water flow velocity in offshore cage aquaculture, this invention provides a mother-daughter cage device for offshore aquaculture. The device comprises a daughter cage unit, a mother cage unit, a daughter cage connecting rope system, a mother cage inclined rope, and a bottom anchor chain system. The daughter cage unit includes a daughter cage float, a daughter cage enclosure net, and a daughter cage enclosure net weight. The mother cage unit includes a mother cage float, a mother cage net panel, and a mother cage net panel weight. The daughter cage connecting rope system has a main rope and auxiliary ropes for the daughter cage. The bottom anchor chain system comprises a bottom ring anchor chain, anchor chains, and anchor piles. The daughter cage enclosure net is an open, semi-enclosed structure with a bottom net panel. The mother cage net panel is a single-circle or multi-circle parallel structure without a bottom or top net panel. Under the action of the mother cage net panel weight, the mother cage net panel can maintain a plumb bob state, thereby creating distance from the internal daughter cage enclosure net and effectively blocking external water velocity. Preferably, the mesh of the mother net cage is made of knotted mesh, and the mesh size is 2-4cm depending on the environmental flow velocity, which can effectively block the water velocity.

[0006] Preferably, the weight of the main mesh panel is a cement block.

[0007] The mother cage float is a closed HDPE pipe structure. Inside the HDPE pipe are foam floats and internal ropes, which serve as safety ropes.

[0008] The device comprises several sub-net cage units, which are connected to each other and to the main net cage via main ropes and auxiliary ropes. Each sub-net cage contains several main ropes, which are arranged along the long side of the main net cage unit, facilitating the maintenance of the overall formation. Preferably, the sub-net cage units adopt an overall circular structure, with each sub-net cage unit distributed tangentially, and auxiliary ropes at the tangent points binding adjacent floating frames together. The circular structure ensures uniform force distribution in all directions, preventing stress concentration, and the tangential distribution of the sub-net cages ensures effective force transmission and formation stability.

[0009] The main rope of the sub-net cage and the perimeter of the mother net cage unit are provided with several radial diagonal support ropes. Preferably, the mesh size of the sub-net cage enclosure is 2-5 cm, depending on the size of the fish fry.

[0010] Preferably, the overall shape of the mother cage unit is oblong, with the long side set in the direction of water flow. At the same time, the internal sub-cage units at both ends of the long side are further away from the mother cage mesh, thereby playing a better role in blocking water flow for the internal sub-cage units.

[0011] Preferably, the main gabion float is composed of two parallel rings of HDPE round pipes with a connecting float between them. This serves two purposes: firstly, it acts as an operating platform for workers; secondly, it significantly reduces the wave height of incoming water waves.

[0012] This invention also provides a marine construction method for a mother-daughter net cage device used in marine aquaculture, comprising the following steps: 1. According to the design drawings, anchor piles are driven into fixed positions on the seabed using BeiDou satellite positioning; 2. Using the anchor piles for positioning, the bottom annular anchor chain and anchor pile anchor chain of the bottom anchor chain system are laid on the seabed; 3. Several pre-assembled sub-net cage units are towed into the area, and then the sub-net cage main ropes and sub-net cage auxiliary ropes are used to connect the various sub-net cage units; 4. Several pre-assembled mother net cage units are arranged near the sub-net cage units, and then the mother net cage floating frame is welded into a whole on the surface work platform; 5. Each outer sub-net cage is connected to the mother net cage unit through the sub-net cage main ropes and sub-net cage auxiliary ropes; 6. The mother net cage unit is connected to the bottom annular anchor chain through several mother net cage diagonal cable ropes.

[0013] This invention employs a mother-and-daughter net cage structure. The mother net cage unit is surrounded by a bottomless, plumb-like mesh. The overall shape of the mother net cage unit is oblong, with its long side aligned with the water flow direction. Simultaneously, the inner daughter net cage units at both ends of the long side are further away from the mother net cage mesh. These features and structures significantly reduce seawater flow velocity, protecting aquaculture organisms and intercepting drifting debris. The oblong shape of the mother net cage unit and the main ropes of the daughter net cages facilitate the erection of floating platforms, thus creating a convenient material transport channel.

[0014] In addition, this invention also provides a method for the marine construction of a mother-daughter net cage device for marine aquaculture, which solves the problem of marine construction of ultra-large net cages, such as those with an outer perimeter of more than 500 meters, and has strong practicality. Attached Figure Description

[0015] Figure 1 , Figure 2 This is a schematic diagram of the first embodiment of the present invention, wherein... Figure 1 This is a top view. Figure 2 This is a sectional view.

[0016] Figure 3 , Figure 4 , Figure 5 This is a schematic diagram of the second embodiment of the present invention, wherein... Figure 3 This is a top view. Figure 4 This is a sectional view. Figure 5 This is a magnified view of a portion of the top view. Detailed Implementation

[0017] First Embodiment

[0018] This invention provides a mother-daughter net cage device for marine aquaculture, such as... Figure 1 , Figure 2 The device comprises a sub-net cage unit 1, a main net cage unit 2, a sub-net cage connecting rope system 3, a main net cage inclined rope 4, and a bottom anchor chain system 5. The sub-net cage unit 1 includes a sub-net cage float 11, a sub-net cage enclosure net 12, and sub-net cage enclosure weights 13. The main net cage unit 2 includes a main net cage float 21, a main net cage mesh 22, and a main net cage mesh weight 23. The sub-net cage connecting rope system 3 has a main sub-net cage rope 31 and a sub-net cage auxiliary rope 32. The bottom anchor chain system 5 comprises a bottom annular anchor chain 51, anchor piles and chains 52, and anchor piles 53. The sub-net cage enclosure net 12 is an open, semi-enclosed structure with a bottom mesh. The main net cage mesh 22 is a circumferential mesh structure without bottom or top mesh. Under the action of the weight block 23, the main mesh panel 22 can maintain a plumb bob state, thereby creating a distance between it and the inner sub-mesh enclosure, allowing for better water velocity blocking. Preferably, the main mesh panel 22 is a knotted net, with a mesh size of 2-4 cm depending on the ambient flow velocity, which can effectively block water velocity.

[0019] The device includes several sub-net cage units 1. Each sub-net cage unit 1, as well as the sub-net cages and the main net cage unit, are connected by sub-net cage main ropes 31 and sub-net cage auxiliary ropes 32. Each sub-net cage unit 1 has several sub-net cage main ropes 31, which are arranged along the long side of the main net cage unit. Sub-net cage auxiliary ropes 32 connect each sub-net cage float 11. The sub-net cage auxiliary ropes 32 also connect the outer sub-net cage floats 11 to the main net cage float 21. The sub-net cage main ropes 31 connect to the corresponding sub-net cage auxiliary ropes 32 and are connected to the main net cage float 21 at both ends. The upper end of each main net cage inclined cable 4 is connected to the main net cage float 21, and the lower end is connected to the bottom annular anchor chain 51. The outer side of the bottom annular anchor chain 51 is connected to the anchor pile anchor chain 52 and then fixed to the anchor pile 53.

[0020] Preferably, the sub-net cages adopt an integral circular structure, with each sub-net cage distributed in a tangential manner and auxiliary ropes at the tangent points binding adjacent floats together. The sub-net cage floats are hollow cylindrical tubes, so that even with the binding of the sub-net cage auxiliary ropes, adjacent sub-net cages can still move and tilt relatively within a small range.

[0021] The mother cage float 21 is a closed HDPE round pipe structure. The HDPE pipe is hollow inside and has foam float and internal ropes. The internal ropes of the float serve as safety ropes.

[0022] like Figure 2The overall shape of the mother cage unit 2 is oblong. When it is arranged in seawater, the long side is set in the direction of water flow. At the same time, the internal sub-cage units at both ends of the long side of the mother cage unit 2 are set to be farther away from the mother cage mesh, so as to better block the water flow of the internal sub-cage units.

[0023] This embodiment also provides a marine construction method for a mother-daughter net cage device used in marine aquaculture, the steps of which are as follows: ① According to the design drawings, anchor piles 53 are driven into the seabed and fixed in position using Beidou satellite positioning; ② Using anchor piles 53 for positioning, the bottom annular anchor chain 51 and anchor pile anchor chain 52 of the bottom anchor chain system 5 on the seabed are laid; ③ Several pre-assembled sub-net cage units 1 are towed into the area, and then the sub-net cage main rope 31 and sub-net cage auxiliary rope 32 are used to connect each sub-net cage unit 1; ④ Several pre-assembled mother net cage units 2 are arranged near the sub-net cage units 1, and then the mother net cage floating frame 2 is welded into a whole on the water operation platform; ⑤ Each outer sub-net cage 1 is connected to the mother net cage unit 2 through the sub-net cage main rope 31 and sub-net cage auxiliary rope 32; ⑥ The mother net cage unit 2 is connected to the bottom annular anchor chain 51 through several mother net cage inclined ropes 4.

[0024] The overall structure employs a mother-and-daughter net cage configuration. The mother net cage unit is surrounded by a plumb bob with no bottom, and its overall shape is elongated oval, with its longer side aligned with the water flow direction. Simultaneously, the inner daughter net cage units at both ends of this longer side are further away from the mother net cage. These features and structures significantly reduce seawater flow velocity, protecting aquaculture organisms and intercepting drifting debris. The elongated oval shape of the mother net cage unit and the main ropes of the daughter net cages facilitate the erection of floating platforms, thus creating a convenient material transport channel.

[0025] In addition, this invention also provides a method for the marine construction of a mother-daughter net cage device for marine aquaculture, which solves the problem of marine construction of ultra-large net cages, such as those with an outer perimeter of more than 500 meters, and has strong practicality.

[0026] Second Embodiment

[0027] This invention provides a mother-daughter net cage device for marine aquaculture, such as... Figure 3 , Figure 4 , Figure 5The device comprises a sub-net cage unit 1, a main net cage unit 2, a sub-net cage connecting rope system 3, a main net cage inclined rope 4, and a bottom anchor chain system 5. The sub-net cage unit 1 includes a sub-net cage float 11, a sub-net cage enclosure net 12, and sub-net cage enclosure net weights 13. The main net cage unit 2 includes a main net cage float 21, a main net cage mesh 22, and a main net cage mesh weight 23. The sub-net cage connecting rope system 3 has a main sub-net cage rope 31 and a sub-net cage auxiliary rope 32. The bottom anchor chain system 5 comprises a bottom annular anchor chain 51, anchor piles and chains 52, and anchor piles 53. There are two differences from the first embodiment: ① The main net cage float 21 of the main net cage unit 2 has an overall double-tube parallel structure, and the main net cage mesh 22 has an overall double-layer parallel structure. Each layer of the main net cage mesh is connected to several main net cage mesh weights 23 at its bottom. The main cage float 21 is composed of two parallel circular tubes with a connecting float 24 between them. The connecting float 24 connects the inner and outer main cage floats at both ends. The connecting float 24 can serve as an operating platform for personnel. The structure of the two parallel main cage floats 21 and the connecting float 24 significantly reduces the wave height of incoming water waves, thereby effectively reducing the water velocity at the sub-cage surface. ② At the connection points (i.e., adjacent tangent points) of each integrally circular sub-cage unit 1, there is a buffer body 14 and a sub-cage connecting rope 15. The buffer body 14 works in conjunction with the sub-cage floats on both sides, and the sub-cage connecting ropes 15 bind adjacent sub-cage floats 11 and buffer bodies 14 together. Preferably, the buffer body 14 has a honeycomb structure inside, and preferably, it is made of seawater-resistant nitrile rubber or neoprene rubber. It should be noted that the main rope 31 of the sub-net cage and the connecting rope 15 of the sub-net cage do not need to be directly connected, so as to achieve a balance between local flexibility and overall formation stability.

[0028] Compared to the first embodiment, the multi-layered mother cage float 21 and mother cage mesh 22 can form a gradient water-blocking structure, thereby providing a better aquaculture environment for the internal sub-cages by reducing water flow velocity. In addition, the buffer body 14 and the sub-cage connecting ropes 15 not only ensure reliable connection between the internal sub-cages to maintain their formation, but also prevent damage to the sub-cage float 11 that may be caused by mutual collisions.

Claims

1. A kind of sub-mother net cage device for offshore culture, the device includes sub-net cage unit (1), mother net cage unit (2), sub-net cage connecting rope system (3), mother net cage stay cable (4), bottom anchor chain system (5) group composition;The sub-net cage unit (1) includes sub-net cage float (11), sub-net cage net (12), sub-net cage net sink block (13);The mother net cage unit (2) includes mother net cage float (21), mother net cage net (22), mother net cage net sink block (23), the sub-net cage connecting rope system (3) has sub-net cage main rope (31) and sub-net cage auxiliary rope (32), the bottom anchor chain system (5) includes bottom ring anchor chain (51), anchor pile anchor chain (52), anchor pile (53) group composition;Its characterized in that The sub-net box enclosure net (12) is a semi-closed structure enclosure net with an open mouth and a bottom net; the mother net box net (22) is a one-week net or a multi-week parallel structure without a bottom and a top net.

2. A sub-mother net cage arrangement for marine farming according to claim 1, characterized in that The sub-net box units (1) are connected by the sub-net box main ropes (31) and the sub-net box auxiliary ropes (32), and the sub-net box unit (1) has a plurality of sub-net box main ropes (31) arranged along the long edge direction of the mother net box unit; the sub-net box auxiliary ropes (32) connect the sub-net box floats (11); the sub-net box auxiliary ropes (32) also connect the peripheral sub-net box floats (11) and the mother net box float (21); the sub-net box main ropes (31) connect the peripheral sub-net box auxiliary ropes (32) at the corresponding positions and are connected to the mother net box float (21) at both ends; the mother net box stay ropes (4) are connected to the mother net box float (21) at the upper end and to the bottom ring anchor chain (51) at the lower end; the bottom ring anchor chain (51) is connected to the anchor pile anchor chain (52) and is then fixed to the anchor pile (53).

3. A sub-mother net cage arrangement for marine farming according to claim 1, characterized in that The mother net box float (21) is a closed HDPE circular pipe structure, the inside of the HDPE pipe is hollow and has a foam float and a float inner pull rope.

4. A sub-mother net cage arrangement for marine farming according to claim 1, characterized in that The overall shape of the mother net box unit (2) is a long circle, and when arranged in seawater, the long edge is arranged in the direction of the water flow.

5. A sub-mother net cage arrangement for marine farming according to claim 1, characterized in that The internal sub-net box units at both ends of the long edge direction of the mother net box unit (2) are arranged to be farther away from the mother net box net.

6. A sub-mother net cage arrangement for marine farming according to claim 4, characterized in that The mother net box float (21) of the mother net box unit (2) is a double-pipe parallel structure, and the mother net box net (22) is a double-layer parallel structure net, and each layer of the mother net box net is connected to a plurality of mother net box net sinkers (23) below.

7. A sub-mother net cage arrangement for marine farming according to claim 6, characterized in that The mother net box float (21) is a two-circle parallel circular pipe structure, and the circular pipes are connected by a connecting float (24), and the two ends of the connecting float (24) are connected to the inner circle mother net box float and the outer circle mother net box float, respectively.

8. A sub-mother net cage arrangement for marine farming according to claim 1, characterized in that The connection of each overall circular sub-net box unit (1) is provided with a buffer body (14) and a sub-net box connecting rope (15) at the adjacent tangent point, the buffer body (14) is matched with the sub-net box floats on both sides, and the adjacent two sub-net box floats (11) and the buffer body (14) are bound together by the sub-net box connecting rope (15).

9. A sub-mother net cage arrangement for marine farming according to claim 8, characterized in that The buffer body (14) is a honeycomb structure, and the buffer body (14) is made of neoprene rubber or chloroprene rubber.

10. A method of offshore construction of a sub-mat cage assembly for offshore farming according to claim 1, characterized in that The steps are as follows: ①. According to the design drawing, the anchor pile (53) is driven into the fixed position on the seabed by the Beidou satellite positioning; ②. The bottom ring anchor chain (51) and the anchor pile anchor chain (52) of the bottom anchor chain system (5) on the seabed are laid by using the anchor pile (53) positioning; ③. A plurality of sub-net box units (1) are dragged into the area, and then the sub-net box main ropes (31) and the sub-net box auxiliary ropes (32) are used to connect the sub-net box units (1); ④. A plurality of assembled mother net box units (2) are arranged near the sub-net box units (1), and then the mother net box float 2 is welded into a whole on the water operation platform; 5. Each peripheral sub-net cage 1 is connected to the mother net cage unit 2 by means of a sub-net cage main rope 31 and a sub-net cage auxiliary rope 32; 6. The mother net cage unit 2 is connected to the bottom ring-shaped anchor chain 51 by means of a plurality of mother net cage stay ropes 4.

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