STEEL STRUCTURE CAGE FOR MARINE CRUSTACEAN AQUACULTURE AND INTEGRATION THEREOF INTO VERTICAL FISH-CRUSTACEAN AQUACULTURE SYSTEM

Abstract

A steel structure cage for marine crustacean aquaculture and integration thereof into a vertical fish-crustacean aquaculture system are disclosed. The steel structure cage includes a steel frame, top, side and bottom net systems, a ballast tank system, and steel grooves. The steel frame includes internal and external steel frames. The steel grooves are fixed on upper and lower ends of the internal steel frame. Edges of the top and bottom net systems are respectively fixed into the corresponding steel grooves. The side net is welded on the internal steel frame. The ballast tank system is arranged between the internal and external steel frames. A HDPE cage is moored to the steel structure cage to form a vertical aquaculture system. Whereby, an ideal culturing environment for marine crustaceans is given and the objective of vertical aquaculture culturing fish at top water layers and culturing prawns (crabs or cowries) at bottom water layers can be fulfilled.

Claims

1. A steel structure cage for marine crustacean aquaculture comprising a top net system, a bottom net system, a side net system, a ballast tank system, a steel frame, and steel grooves, wherein the steel frame comprises an internal steel frame and an external steel frame, and the steel grooves are fixed on upper and lower ends of the internal steel frame; the top net system and the bottom net system are weaved by nets and net tendons; edges of the top net system and the bottom net system are fixed into the corresponding steel grooves; the side net system is a steel net system and is welded on the internal steel frame; the ballast tank system is arranged between the internal steel frame and the external steel frame; and the bottom net system lies onto the seabed during culturing.

2. The steel structure cage for marine crustacean aquaculture according to claim 1, wherein the top net system is made of either nylon or polyethylene.

3. The steel structure cage for marine crustacean aquaculture according to claim 1, wherein the bottom net system is made of either nylon or polyethylene.

4. The steel structure cage for marine crustacean aquaculture according to claim 1, wherein both the internal steel frame and the external steel frame comprise columns, a baffle is welded on the bottom of each of the columns of the internal and external steel frames, a conical structure is welded on the baffle, and the area of the baffle is greater than the cross-sectional area of the column.

5. The steel structure cage for marine crustacean aquaculture according to claim 1, wherein both the internal steel frame and the external steel frame comprise columns, and the columns of the external steel frame are higher than those of the internal steel frame.

6. The steel structure cage for marine crustacean aquaculture according to claim 1, further comprising lifting lugs, wherein the lifting lugs are fixed on the top of the columns of the internal steel frame.

7. The steel structure cage for marine crustacean aquaculture according to claim 1, further comprising a feeding pipe, wherein one end of the feeding pipe is connected to a buoy and freely floats on the water surface, and the other end of the feeding pipe is placed inside the cage through the center of the top net system.

8. The steel structure cage for marine crustacean aquaculture according to claim 1, wherein the top net system is fastened with floaters and the bottom net system is fastened with heavy sinkers.

9. A vertical fish-crustacean aquaculture system, comprising a high density polyethylene (HDPE) cage, mooring lines, cables, and the steel structure cage for marine crustacean aquaculture according to claim 1, wherein during culturing, the HDPE cage floats on the water surface, the steel structure cage for marine crustacean aquaculture sits on the seabed, the HDPE cage is moored to the steel structure cage for marine crustacean aquaculture by the mooring lines, and a net system of the HDPE cage is connected to the steel structure cage for marine crustacean aquaculture by the cables to maintain the shape of the net system of the HDPE cage.

10. The vertical fish-crustacean aquaculture system according to claim 9, wherein both the internal steel frame and the external steel frame comprise columns, and the columns of the external steel frame are higher than those of the internal steel frame, so that during an offshore towing process, the steel structure cage for marine crustacean aquaculture can directly float on the water surface, and support the HDPE cage which is located inside the external steel frame.

Description

BRIEF DESCRIPTION

[0026] FIG. 1 is a front view of a vertical fish-crustacean aquaculture system according to an embodiment of the present application;

[0027] FIG. 2 is a top view of a steel structure cage for marine crustacean aquaculture according to an embodiment of the present application;

[0028] FIG. 3 is an arrangement diagram of a steel frame and a ballast tank system of a steel structure cage for marine crustacean aquaculture according to an embodiment of the present application;

[0029] FIG. 4 is a schematic diagram of a specially customized stainless steel groove of a steel structure cage for marine crustacean aquaculture according to an embodiment of the present application;

[0030] FIG. 5 is a connection diagram of a mooring line of a steel structure cage for marine crustacean aquaculture according to an embodiment of the present application;

[0031] FIG. 6 is a connection diagram of a cable maintaining the shape of a net of a HDPE (circular) cage according to an embodiment of the present application; and

[0032] FIG. 7 is a three-dimensional diagram of a vertical fish-crustacean aquaculture system according to an embodiment of the present application.

DETAILED DESCRIPTION

[0033] The following further describes exemplary embodiments of the present application in detail.

[0034] As shown in FIG. 1 to FIG. 7, a steel structure cage for marine crustacean aquaculture in an embodiment includes a steel frame 11, a top net system 12, a bottom net system 12, a side net system 13, a ballast tank system 14, and a feeding pipe 15. The steel frame 11 includes an internal steel frame and an external steel frame and the cross section of the steel frame 11 is a regular polygon. The top net system 12 and the bottom net system 12 are weaved by nylon or polyethylene nets and net tendons. Edges of the top net system 12 and the bottom net system 12 are fixed into the steel grooves 16, so that the top net system 12 and the bottom net system 12 are connected to the internal frame of the steel frame 11 in a seamless manner. The side net system 13 is a stainless steel net and is welded on the internal frame of the steel frame 11. That is, the bottom net system 12, the side net system 13 and the top net system 12 form an enclosed culturing space. Certainly, the term enclosed herein (the same below) means that cultured marine crustaceans cannot escape from this culturing space to the sea while seawater can freely flow in and out of this culturing space. The ballast tank system 14 is arranged between the internal steel frame and the external steel frame of the steel frame 11.

[0035] In an embodiment, the steel frame 11 is a structure comprised of vertical steel pipes (columns), horizontal steel pipes, and inclined steel pipes. As shown in FIG. 3, a circular baffle 110 is welded at the bottom of each column of the internal and external steel frames of the steel frame 11, a conical structure 111 is welded on the circular baffle 110, and the circular baffle 110 has a diameter greater than the diameter of the column of the steel frame.

[0036] In an embodiment, the top net system 12 is fastened with floaters and the bottom net system 12 is fastened with heavy sinkers. The net tendons at the edges of the top net system 12 and the bottom net system 12 are secured in the stainless steel grooves 16. Movable cover plates 112 are used to connect the stainless steel grooves 16 to keep the net tendons in the stainless steel grooves 16. The stainless steel grooves 16 are welded on the horizontal steel pipes around the top and bottom of the internal frame of the steel frame 11.

[0037] In an embodiment, the ballast tank system 14 is formed by multiple HDPE pipes. The HDPE pipes do not communicate with each other and serve as independent cabins. The HDPE pipes of the ballast tank system 14 are fixed at the bottom of the steel frame 11 by hoops 17, and the HDPE pipes are located between the internal steel frame and the external steel frame.

[0038] In an embodiment, one end of the feeding pipe 15 is connected to a buoy and freely floats on the water surface, and the other end of the feeding pipe is placed inside the cage through the center of the top net system.

[0039] In an embodiment, the columns 18 of the external steel frame of the steel frame are higher than the columns 19 of the internal steel frame.

[0040] As shown in FIG. 5 and FIG. 6, in an embodiment, the top of each column 19 of the internal frame is welded with a U-shaped steel lifting lug for the connection use of mooring lines 3 and cables 4.

[0041] As shown in FIG. 1, FIG. 5, FIG. 6, and FIG. 7, a vertical fish-crustacean aquaculture system in an embodiment includes a HDPE (circular) cage 2, mooring lines 3, cables 4, and the steel structure cage 1 for marine crustacean aquaculture described above. During culturing, the HDPE (circular) cage 2 floats on the water surface, and the steel structure cage 1 for marine crustacean aquaculture sits on seabed. The HDPE (circular) cage 2 is moored to the steel structure cage 1 for marine crustacean aquaculture by the mooring lines 3, and the net system of the HDPE (circular) cage 2 is connected to the steel structure cage 1 for marine crustacean aquaculture by the cables 4 to maintain the shape of the net system of the HDPE (circular) cage 2.

[0042] At the construction stage, the HDPE (circular) cage and the steel structure cage for marine crustacean aquaculture are first manufactured onshore. The construction of the HDPE (circular) cage can be easily fulfilled by present industrial technologies, or ordered from the current market. For the construction of the steel structure cage for marine crustacean aquaculture, the steel frame needs to be fabricated first. The number of sides of the regular polygon steel frame is the same as the number of sides of the steel structure cage for marine crustacean culturing. Each side of the regular polygon double-layered steel frame is welded in factory and then transported to the shore for assembly. When the fabrication of the steel frame is completed, the ballast tank system and the net systems are installed on the steel frame. After fabrication of the whole steel structure cage for marine crustacean aquaculture is completed, air is pumped into the ballast tank system. After the inflation is completed, first, the steel structure cage for marine crustacean aquaculture is lifted into water from the beach, and then the HDPE (circular) cage is lifted right above the steel structure cage for marine crustacean aquaculture, and next, the net system of the HDPE (circular) cage is connected to the U-shaped lifting lugs at the upper end of the columns of the internal steel frame of the steel structure cage for marine crustacean aquaculture with the cables, and floating collar of the HDPE (circular) cage is connected to the U-shaped lifting lugs with mooring lines. After these connections are done, the HDPE (circular) cage is placed on the steel frame of the steel structure cage for marine crustacean aquaculture (inside the external steel frame). The two cages are towed together by a tugboat. Because the center of gravity is very low, a good towing stability is ensured. When reaching the culturing site, the outlet valve of each air-duct is opened for the inside air to escape from the rubber capsules, and seawater enters the HDPE pipes. When the gravity of the steel structure cage for marine crustacean aquaculture is greater than its buoyancy, the steel structure cage for marine crustacean aquaculture gradually sinks to the seabed under the gravitational force, and the HDPE (circular) cage floats on the water surface due to the buoyancy force of the HDPE floating collar. In this way, the cables and the mooring lines are tightened, and the installation of the vertical fish-crustacean aquaculture system is completed.

[0043] During culturing operations, an automatic feeding system is used. The system includes an automatic feeding machine on a workboat. The feed is transferred from the workboat to the cages through pipes. One end of the feeding pipe of the steel structure cage for marine crustacean aquaculture is located in the cage, and the other end is connected to a buoy and freely floats on the water surface. For the HDPE (circular) cage, in order to spread feed evenly, a rotor spreader connected with a feeding pipe is adopted, and a small-size HDPE floating base which is located at the center of the HDPE (circular) cage and floats on the water surface is used to support the rotor spreader. When the feeding clock is on, a cage's feeding pipe is connected to the automatic feeding machine to activate feeding. In this case, the machine is multifunctional and costs are reduced.

[0044] The method of catching fish in the HDPE (circular) cage may use present technologies. For catching crustaceans in the steel structure cage for marine crustacean aquaculture, the mooring lines and the cables between the HDPE (circular) cage and the steel structure cage for marine crustacean aquaculture are disconnected first. Then air is pumped into the ballast tank system of the steel structure cage for marine crustacean aquaculture. When buoyancy of the steel structure cage is greater than its gravity, the steel structure cage gradually floats towards the water surface. The space between the internal and external steel frames at the top surface of the steel structure cage is the operation platform for fishermen. Catching can be performed by removing the movable cover plates from the specially customized stainless steel grooves and then removing the top net system.

[0045] The above contents are detailed descriptions of the present application in conjunction with specific preferred implementations, and it should not be considered that the specific implementations of the present application are limited to these descriptions. Those of ordinary skill in the art may also make some deductions or replacements without departing from the conception of the present application and all of such deductions or replacements should be considered to be within the scope of the protection as determined by the claims.