Freshwater fish recirculating aquaculture system and method

Abstract

The invention provides a freshwater fish recirculating aquaculture system and method, and relates to the technical field of aquaculture. The culture system comprises a culture pond, a microfilter, a biological pond, a water storage pond, aeration equipment, disinfection equipment and oxygen production equipment. The freshwater fish recirculating aquaculture system has the advantages that the heights of the culture pond, the microstrainer, the biological pond and the water storage pond of the culture system are sequentially reduced, the culture pond, the microstrainer, the biological pond and the water storage pond are sequentially connected through the water return pipe, and the bottom of the water storage pond is connected with the water inlet pipe through the circulating water pump. Therefore, the running energy consumption of the whole system can be reduced, and the breeding cost is reduced; aeration equipment is arranged in the water storage tank, oxygen generation equipment connected with the aeration equipment can pump high-concentration oxygen into the water storage tank to improve the concentration of dissolved oxygen in water, water is injected into the culture pond at a certain incident angle through water outlet holes in a water inlet branch pipe in the water storage tank, a stable flow field is formed in the water in the culture pond, and the culture density of the culture system is improved.

Description

Technical Field

[0001] The invention relates to the technical field of aquaculture, and in particular to a freshwater fish circulating water culture system and method. Background Art

[0002] The recirculating aquaculture system mainly relies on physical filtration, biological treatment, disinfection and sterilization to purify the aquaculture tailwater, and control the water quality indicators within the appropriate range for fish growth. It has the advantages of high aquaculture density, environmental protection, and resource conservation. However, due to the unreasonable design of the recirculating aquaculture system, the fish feces are not discharged in time, causing the feces to mix with the aquaculture water for a long time, increasing the cost of tailwater treatment; the system operation is complicated, resulting in high learning costs; the configuration is unreasonable and the structure is complicated, resulting in high initial construction capital costs; the system operation requires a lot of energy, resulting in high costs in the aquaculture process. Summary of the invention

[0003] In view of this, the present invention provides a freshwater fish circulating water culture system, comprising a water inlet pipe, a culture pond, a microfilter, a biological pond and a water reservoir;

[0004] The bottom of the culture pond is also provided with a sewage pipe and a return pipe, the return pipe connects the culture pond and the microfilter, the microfilter and the biological pool are connected through the microfilter outlet pipe, the biological pool and the water storage tank are connected through the biological pool outlet pipe, and a sewage valve is provided on the sewage pipe;

[0005] The biological pond is provided with an aeration and oxygenation device, the water reservoir is provided with a disinfection device, an aeration device and a circulating water pump, one end of the water inlet pipe is connected to the circulating water pump in the water reservoir, and the other end of the water inlet pipe is connected to the breeding pond, the circulating water pump is used to continuously pump water in the water reservoir into the breeding pond, so that the water in the breeding pond circulates between the breeding pond, the microfilter, the biological pond and the water reservoir, the microfilter is used to filter fish feces and residual feed in the water passing through it, and the biological pond is used to purify the water passing through it.

[0006] Furthermore, there are multiple breeding ponds, and each breeding pond is provided with three water inlet branches, and the water inlet branches are all connected to the water inlet pipe.

[0007] Furthermore, the water inlet branch pipe vertically extends into the breeding pond, and a plurality of water outlet holes are provided on the portion of the water inlet branch pipe extending into the breeding pond.

[0008] Furthermore, the breeding pond is a cylindrical pond body, the water inlet branch pipe is close to the inner wall of the breeding pond, three water inlet branches are evenly arranged along the inner wall of the breeding pond, the water outlet hole is horizontally arranged, and the water outlet direction of the water outlet angle hole is at an angle of 45° to the tangent direction of the inner wall of the breeding pond, so that the water sprayed from the water outlet hole can drive the water body in the breeding pond to rotate and flow, and achieve a stable flow field.

[0009] Furthermore, the water reservoir is also provided with a water supply pipe, one end of which is connected to a water supply device, and the other end extends into the water reservoir. An automatic water supply valve is provided at the end of the water supply pipe extending into the water reservoir. An overflow pipe is also provided on the upper side wall of the water reservoir. The water supply pipe is used to supply water into the water reservoir, and the overflow pipe is used to control the water level in the water reservoir.

[0010] Furthermore, the automatic water replenishment valve is a buoyancy valve, the height of the automatic water replenishment valve is lower than the height of the overflow pipe, and the buoyancy valve automatically opens after the water level is lower than its height, thereby replenishing water to the breeding pond.

[0011] Furthermore, the biological pool is filled with biological filter material fillers, and the biological filter material fillers contain nitrifying bacteria groups. The aeration and oxygenation equipment is arranged at the bottom of the biological pool, and the aeration and oxygenation equipment is used to blow air into the biological pool.

[0012] Furthermore, the aeration equipment in the water reservoir is a micro-nano aeration plate, and an oxygen production equipment is provided outside the water reservoir. The oxygen production equipment is connected to the aeration equipment, and the oxygen production equipment is used to produce high-concentration oxygen. The aeration equipment is used to pass the oxygen produced by the oxygen production equipment into the water reservoir.

[0013] The present invention also provides a freshwater fish circulating water culture method, which uses the above-mentioned freshwater fish circulating water culture system and comprises the following steps:

[0014] S1: Assemble the freshwater fish recirculating water aquaculture system and fill all aquaculture ponds and reservoirs with water;

[0015] S2: Determine the cultured fish and culture density according to the specification parameters of the freshwater fish circulating water culture system;

[0016] S3: putting the farmed fish determined in step S2 into corresponding breeding ponds according to breeding density;

[0017] S4: Start the circulating water pump, microfiltration machine, aeration and oxygenation equipment, disinfection equipment, and aeration equipment. The circulating water pump continuously pumps water from the reservoir into the breeding pond, drives the water in the breeding pond to rotate and flow, and forms a stable flow field, and replenishes the water in the breeding pond to increase the water level in the breeding pond. Part of the water in the breeding pond overflows from the return pipe into the microfiltration machine, and then flows back to the reservoir through the microfiltration machine and the biological pool in turn.

[0018] Furthermore, the above step S4 also includes the following steps: opening the drain valve on the drain pipe at the bottom of the culture pond to discharge part of the sewage at the bottom of the culture pond, wherein the amount of sewage discharged from the drain pipe every day is 3%-10% of the total water volume in the culture pond.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects:

[0020] The freshwater fish circulating water breeding system includes a breeding pond, a microfiltration machine, a biological pond, a water reservoir, an aeration device, a disinfection device and an oxygen production device. It has a simple structure, a clear connection method, a reasonable design and requires less initial construction funds.

[0021] The freshwater fish circulating water breeding system can make most of the water in the breeding pond circulate in the microfiltration machine, the biological pool and the reservoir. The circulating water is filtered by the microfiltration machine and purified by the biological pool in turn. The treated water returns to the reservoir and is pumped back to the breeding pond by the bottom pump structure after aeration, thus forming a whole water cycle. The steps are simple, easy for staff to understand and the learning cost is low.

[0022] The heights of the breeding pond, microfiltration machine, biological pond and water storage tank of the freshwater fish circulating water breeding system are successively reduced and connected through a return pipe in sequence. The bottom of the water storage tank is connected to the water inlet pipe through a circulating water pump. The freshwater fish circulating water breeding system only needs one pump body to realize the circulation flow of the water body, which can reduce the energy consumption of the entire system operation and thus reduce the breeding cost of freshwater fish.

[0023] The water reservoir of the freshwater fish circulating water culture system is provided with an aeration device connected with the oxygen production device. The aeration device can pump high-concentration oxygen into the water reservoir to increase the dissolved oxygen concentration in the water body. The water in the water reservoir can be injected into the culture pond under the action of a circulating pump. In the water injection process, the water outlet holes on the water inlet branch pipe in the culture pond inject water at a certain incident angle. The water outlet hole structure on the water inlet branch pipe can create a reasonable water flow rate and a stable internal water flow field in the culture pond to promote the growth of the cultured objects, quickly discharge fish feces, and reduce the subsequent pressure of aquaculture wastewater treatment, thereby achieving the effect of high aquaculture density. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a stereoscopic diagram of a freshwater fish circulating aquaculture system according to an embodiment of the present invention.

[0025] Figure 2 It is a top view of a freshwater fish circulating aquaculture system according to an embodiment of the present invention.

[0026] Figure 3 It is a stereoscopic diagram of a breeding pond of a freshwater fish circulating water breeding system according to an embodiment of the present invention.

[0027] Figure 4 It is a side view of a breeding pond of a freshwater fish circulating aquaculture system according to an embodiment of the present invention.

[0028] Figure 5It is a simulation diagram of the water flow field in a breeding pond of a freshwater fish circulating water breeding system according to an embodiment of the present invention (in the figure, Q is the number of water inlet branch pipes, H is the number of water inlet branch pipe holes, and A is the incident angle of the water inlet branch pipe).

[0029] In the above figure: 1-breeding pond, 2-extraction pipe, 3-return pipe, 4-drain pipe, 5-water inlet pipe, 6-microfiltration machine inlet pipe, 7-microfiltration machine, 8-microfiltration machine outlet pipe, 9-biological pool, 10-biological pool outlet pipe, 11-reservoir, 12-microfiltration machine drain pipe, 13-water supply pipe, 14-disinfection equipment, 15-aeration equipment, 16-circulating water pump, 17-aeration and oxygenation equipment, 18-water outlet, 19-automatic water supply valve, 20-overflow pipe, 21-oxygen production equipment. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0031] Please refer to Figures 1 to 5 A freshwater fish circulating water culture system of the present invention comprises a water inlet pipe 5, a culture pond 1, a microfilter 7, a biological pond 9 and a water reservoir 11. The culture pond 1, the biological pond 9 and the water reservoir 11 are all cylindrical pool bodies.

[0032] The bottom of the breeding pond 1 is a truncated cone structure, the bottom slope of the breeding pond 1 is 10-15 degrees, the diameter of the breeding pond is 1m-6m, and the depth of the breeding water body is 1.2m-2.0m.

[0033] A sewage pipe 4 and a return pipe 3 are provided at the bottom of the culture pond 1, and a sewage valve is provided on the sewage pipe 4. The return pipe 3 connects the culture pond 1 and the microfilter 7, wherein the return pipe 3 connects the culture pond 1 and the pull-out pipe 2, and the pull-out pipe 2 is connected to the microfilter 7 on the microfilter inlet pipe 6, the microfilter 7 and the biological pool 9 are connected through the microfilter outlet pipe 8, and the biological pool 9 and the water storage tank 11 are connected through the biological pool outlet pipe 10.

[0034] The biological pond 9 is provided with an aeration and oxygenation device 17, the water reservoir 11 is provided with a disinfection device 14, an aeration device 15 and a circulating water pump 16, and an oxygen production device 21 is provided outside the water reservoir 11. The oxygen production device 21 is connected to the aeration device 15. The oxygen production device 21 is used to introduce oxygen into the water reservoir 11, and the oxygen is introduced into the aeration device 15 and is blown into the water body of the water reservoir 11, thereby increasing the dissolved oxygen concentration in the water body of the water reservoir 11.

[0035] In this embodiment, the oxygen production equipment 21 is a high-concentration industrial PSA (Pressure Swing Absorption) oxygen production device (also called pressure swing adsorption oxygen production equipment), which can continuously provide gas with an oxygen concentration of 93% ± 3%. The principle is: under normal temperature and pressure conditions, air is used as a raw material to selectively adsorb impurities such as nitrogen, carbon dioxide and water in the air using a PSA special molecular sieve, thereby obtaining a mixed gas with a high oxygen concentration. The aeration equipment 15 is a micro-nano aeration disk, and the aeration equipment 15 is connected to the oxygen production equipment 21 through a pipeline. The oxygenation efficiency of the oxygenation assembly formed by the aeration equipment 15 and the oxygen production equipment 21 can reach 30% to 50%. Traditional oxygenation methods, such as low-pressure pure oxygen mixed oxygenation (LHO) and oxygen cone oxygenation, can increase the dissolution efficiency of high-dissolved oxygen gas to more than 50%, but they all have the disadvantages of expensive equipment and high operating costs. The oxygenation assembly formed by the aeration equipment 15 and the oxygen production equipment 21 in this embodiment operates stably and meets the breeding needs. It not only reduces the initial purchase cost of the system, but also reduces the energy consumption during the operation of the system.

[0036] One end of the water inlet pipe 5 is connected to the circulating water pump 16 in the water reservoir 11, and the other end of the water inlet pipe 5 is connected to the breeding pond. The circulating water pump 16 is used to continuously pump the water in the water reservoir 11 into the biological pool, so that the water in the breeding pool 1 circulates between the breeding pool 1, the microfilter 7, the biological pool 9 and the water reservoir 11. The microfilter 7 is used to filter the fish feces and residual feed passing through its water body. The biological pool 9 is used to eliminate harmful substances such as organic matter, ammonia nitrogen, nitrite, sulfide and phosphate passing through its water body to purify the water body. The microfilter 7 is connected to a microfilter sewage pipe 12, and the microfilter sewage pipe 12 is used to discharge the sewage filtered by the microfilter.

[0037] The diameter of the water inlet pipe 5 increases with the increase of the diameter of the culture pond 1, and the diameter of the water inlet pipe 5 is between 25mm and 75mm. The biological pool 9 is placed adjacent to the microfilter 7, and the height of the biological pool 9 is lower than the height of the outlet pipe of the microfilter. The volume of the biological pool 9 is 30%-60% of the total volume of the culture water body. The biological pool 9 is filled with biological filter material fillers, and the surface of the biological filter material fillers has a biofilm. The biofilm includes a nitrifying bacteria group composed of a variety of nitrifying bacteria, organic debris and polysaccharides. The nitrifying bacteria group functions to decompose harmful substances such as organic matter, ammonia nitrogen, nitrite, sulfide and phosphate in the culture water. The aeration and oxygenation equipment 17 is arranged at the bottom of the biological pool 9. The aeration and oxygenation equipment 17 is used to blow air into the biological pool 9 to maintain a high dissolved oxygen level in the water body and remove harmful gases generated in the water body. The filling degree of biological filter material inside the biological pool 9 is designed to be 50%-70%, and the height of the microfilter water inlet pipe 6 is 25-40 cm lower than the water surface of the breeding pool; the water treatment capacity of the microfilter is configured according to twice the total volume of the breeding water body.

[0038] Furthermore, there are multiple breeding ponds 1. In the present embodiment, there are three breeding ponds 1. Three water inlet branches are arranged in each breeding pond 1, and the water inlet branches are connected to the water inlet pipe 5. The water inlet branch extends vertically into the breeding pond, and the portion of the water inlet branch extending into the breeding pond 1 is provided with six water outlet holes 18. The water outlet holes 18 are arranged equidistantly at the lower end of the water inlet branch, and the lower end of the water inlet branch is open and closed. The water inlet branch is close to the inner wall of the breeding pond 1, and adjacent water inlet branches are distributed in a 120° circle in the breeding pond. The water outlet holes 18 are arranged horizontally, and the water outlet direction of the water outlet hole 18 is at a 45° angle to the tangent direction of the inner wall of the breeding pond, so that the water sprayed from the water outlet hole 18 can drive the water body in the breeding pond to rotate and flow, thereby ensuring that the water body in the breeding pond flows fully and forms a stable flow field. Refer to Figure 5 The flow field distribution diagram of the above-mentioned water inlet structure simulated by CFD software Fluent; the arrangement of the above-mentioned water inlet branch pipe and the water outlet 18 thereon can make the water in the breeding pond obtain a uniform and stable flow field, under which the feces and residual bait of the farmed fish can be discharged to the outside of the circulating water system through the microfiltration machine in a relatively short time. This method reduces the time for collecting pollutants, reduces the difficulty of decomposing feces, and reduces the pressure on the subsequent treatment of pollutants such as ammonia nitrogen, nitrite nitrogen, and microorganisms, so as to increase the breeding density while keeping the original system processing capacity unchanged.

[0039] Furthermore, the heights of the breeding pond 1, the microfiltration machine 7, the biological pond 9 and the water reservoir 11 of the freshwater fish circulating water breeding system are successively reduced and connected in sequence. The bottom of the water reservoir 11 is connected to the water inlet pipe 5 through the circulating water pump 16. The freshwater fish circulating water breeding system only needs one pump body to realize the circulation flow of the water body, which can reduce the energy consumption of the entire system operation, thereby reducing the breeding cost of freshwater fish.

[0040] Furthermore, a water supply pipe 13 is also provided on the water reservoir 11, one end of the water supply pipe 13 is connected to a water supply device, and the other end extends into the water reservoir 11, and an automatic water supply valve 19 is provided at the end of the water supply pipe 13 extending into the water reservoir. An overflow pipe 20 is also provided on the upper side wall of the water reservoir 11, and the water supply pipe is used to replenish water into the water reservoir 11, and the overflow pipe 20 is used to control the water level height in the water reservoir 11.

[0041] Furthermore, the automatic water replenishment valve 19 is a buoyancy valve, the height of the automatic water replenishment valve 19 is lower than the height of the overflow pipe 20, and the buoyancy valve automatically opens after the water level is lower than its height, thereby replenishing water to the breeding pond.

[0042] The present invention also provides a freshwater fish circulating water culture method, which uses the above-mentioned freshwater fish circulating water culture system and comprises the following steps:

[0043] S1: Assemble the freshwater fish circulating water culture system and fill water into all the culture ponds and the reservoir 11;

[0044] S2: Determine the cultured fish and culture density according to the specification parameters of the freshwater fish recirculating aquaculture system;

[0045] S3: putting the farmed fish determined in step S2 into the corresponding breeding pond 1 according to the breeding density;

[0046] S4: Start the circulating water pump 16, the microfilter, the aeration and oxygenation equipment 17, the disinfection equipment 14, and the aeration equipment 15. The circulating water pump 16 continuously pumps the water in the water reservoir into the culture pond 1, drives the water in the culture pond 1 to rotate and flow to form a stable flow field, and replenishes the water in the culture pond 1 to increase the water level in the culture pond. Part of the water in the culture pond overflows from the return pipe 3 into the microfilter 7, and flows back to the water reservoir 11 through the microfilter 7 and the biological pool 9 in turn.

[0047] The above step S4 also includes the following steps: opening the drain valve on the drain pipe 4 at the bottom of the culture pond to discharge part of the sewage at the bottom of the culture pond, wherein the amount of sewage discharged from the drain pipe 4 every day is 3%-10% of the total water volume in the culture pond, the water input into the culture pond by the circulating water pump 16 is greater than the water discharged from the drain pipe 4, the water discharged from the culture pond 1 through the drain pipe 4 is supplemented by the water in the reservoir 1 to maintain the water level of the culture pond, the water discharged from the drain pipe 4 is the water at the bottom of the culture pond, and the water in this part of the water is highly polluted, and discharging this part of the water can greatly reduce the aquaculture wastewater treatment pressure of the microfiltration machine 7 and the biological pool 9.

[0048] In this document, the directional words such as front, back, top, and bottom are defined by the positions of the components in the drawings and the positions of the components relative to each other, and are only for the sake of clarity and convenience in expressing the technical solution. It should be understood that the use of the directional words should not limit the scope of protection claimed in this application.

[0049] In the absence of conflict, the above embodiments and features in the embodiments may be combined with each other.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A freshwater fish circulating water culture system, characterized in that: Including water inlet pipe, breeding pond, microfiltration machine, biological pool and water storage tank; A sewage pipe and a return pipe are provided at the bottom of the culture pond, the return pipe connects the culture pond and the microfilter, the microfilter and the biological pool are connected through a microfilter outlet pipe, the biological pool and the water storage tank are connected through a biological pool outlet pipe, and a sewage valve is provided on the sewage pipe; The biological pond is provided with an aeration and oxygenation device, the water reservoir is provided with a disinfection device, an aeration device and a circulating water pump, one end of the water inlet pipe is connected to the circulating water pump in the water reservoir, and the other end of the water inlet pipe is connected to the breeding pond, the circulating water pump is used to continuously pump the water in the water reservoir into the breeding pond, so that the water in the breeding pond circulates between the breeding pond, the microfilter, the biological pond and the water reservoir, the microfilter is used to filter the fish feces and residual feed in the water passing through it, and the biological pond is used to purify the water passing through it.

2. A freshwater fish circulating water culture system according to claim 1, characterized in that: There are multiple breeding ponds, and each breeding pond is provided with three water inlet branches, and the water inlet branches are all connected to the water inlet pipe.

3. A freshwater fish circulating water culture system according to claim 2, characterized in that: The water inlet branch pipe vertically extends into the breeding pond, and a plurality of water outlet holes are arranged on the portion of the water inlet branch pipe extending into the breeding pond.

4. A freshwater fish circulating water culture system according to claim 3, characterized in that: The breeding pond is a cylindrical pond body, the water inlet branch pipe is close to the inner wall of the breeding pond, three water inlet branch pipes are evenly arranged along the inner wall of the breeding pond, the water outlet hole is horizontally arranged, and the water outlet direction of the water outlet angle hole is at an angle of 45° to the tangent direction of the inner wall of the breeding pond, so that the water sprayed from the water outlet hole can drive the water body in the breeding pond to rotate and flow, and achieve a stable flow field.

5. A freshwater fish circulating water culture system according to claim 4, characterized in that: The water reservoir is also provided with a water supply pipe, one end of which is connected to a water supply device, and the other end extends into the water reservoir. An automatic water supply valve is provided at the end of the water supply pipe extending into the water reservoir. An overflow pipe is also provided on the upper side wall of the water reservoir. The water supply pipe is used to supply water to the water reservoir, and the overflow pipe is used to control the water level in the water reservoir.

6. A freshwater fish circulating water culture system according to claim 5, characterized in that: The automatic water replenishment valve is a buoyancy valve, the height of the automatic water replenishment valve is lower than the height of the overflow pipe, and the buoyancy valve automatically opens after the water level is lower than its height, thereby replenishing water to the breeding pond.

7. A freshwater fish circulating water culture system according to claim 1, characterized in that: The biological pool is filled with biological filter material fillers, and the biological filter material fillers contain nitrifying bacteria groups. The aeration and oxygenation equipment is arranged at the bottom of the biological pool. The aeration and oxygenation equipment is used to blow air into the biological pool to maintain a high dissolved oxygen level in the water body of the biological pool and remove harmful gases generated in the water body.

8. A freshwater fish circulating water culture system according to claim 1, characterized in that: The aeration equipment in the water reservoir is a micro-nano aeration plate. An oxygen production equipment is arranged outside the water reservoir. The oxygen production equipment is connected to the aeration equipment. The oxygen production equipment is used to produce high-concentration oxygen. The aeration equipment is used to pass the oxygen produced by the oxygen production equipment into the water reservoir.

9. A method for circulating aquaculture of freshwater fish, characterized in that: The freshwater fish circulating aquaculture system according to any one of claims 1 to 8 is used, and comprises the following steps: S1: Assemble the freshwater fish recirculating water aquaculture system and fill all aquaculture ponds and reservoirs with water; S2: Determine the cultured fish and culture density according to the specification parameters of the freshwater fish circulating water culture system; S3: putting the farmed fish determined in step S2 into corresponding breeding ponds according to breeding density; S4: Start the circulating water pump, microfiltration machine, aeration and oxygenation equipment, disinfection equipment, and aeration equipment. The circulating water pump continuously pumps water from the reservoir into the breeding pond, drives the water in the breeding pond to rotate and flow, and forms a stable flow field, and replenishes the water in the breeding pond to increase the water level in the breeding pond. Part of the water in the breeding pond overflows into the microfiltration machine from the return pipe in turn, and then flows back to the reservoir through the microfiltration machine and the biological pool in turn.

10. A freshwater fish circulating water culture method according to claim 9, characterized in that: The above step S4 also includes the following steps: opening the drain valve on the drain pipe at the bottom of the culture pond to drain some of the sewage at the bottom of the culture pond, wherein the amount of sewage discharged from the drain pipe every day is 3%-10% of the total water volume in the culture pond.

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