Fish collecting device based on negative pressure non-contact fish suction

Abstract

The invention discloses a fish collecting device based on negative pressure non-contact fish suction, a main body is a hollow fish collecting tank body, and the fish collecting device is provided with functional pipelines such as a fish suction pipeline, a fish discharge pipeline, a vent valve, an oxygen valve, a high-low drain pipe and the like, and pressure and liquid level sensors. The base is made of stainless steel, a transparent window is arranged in the middle of the base, and an access hole is formed in the top of the base. The control host is connected with the valves, the water pump and the sensor to achieve automatic control. During working, water is pumped into the tank body firstly, then part of water is pumped out to form negative pressure, fish is sucked through the negative pressure, inlet and outlet flow is kept consistent during fish suction so as to maintain constant pressure in the tank, and temporary rearing or fish discharging can be achieved. The device avoids mechanical damage to fish bodies, and is relatively simple in structure, low in cost and suitable for catching and conveying fishes in large-scale facility culture in deep and far sea.

Description

Technical Field

[0001] The present invention relates to aquaculture, and a fish collecting device based on negative pressure non-contact fish suction. Background Art

[0002] For large-scale deep-sea and far-sea aquaculture facilities, a single large cage can produce dozens of tons of finished live fish, which poses higher requirements for supporting equipment. Large-scale and intelligent deep-sea and far-sea aquaculture engineering equipment and supporting facilities are the key to carrying out large-scale deep-sea and far-sea aquaculture. As an important operation link in deep-sea aquaculture, the catching and conveying of fish have a large amount of fish caught at one time, large-sized adult fish, and a large lifting height for catching. This requires the equipment to be able to achieve fast, non-destructive, and intelligent operation. The research and development of efficient and non-destructive live fish catching technology and equipment face huge challenges.

[0003] At home and abroad, centrifugal or vacuum fish pumps are mostly used to catch and convey fish. Among them, the main technical defect of the centrifugal fish pump is that the fish body needs to pass through high-speed rotating components, resulting in a high damage rate and being unsuitable for the conveyance of large-sized fish bodies (above 1 kg). However, it can achieve continuous and efficient catching operations, and has a compact structure and low cost. The traditional vacuum fish pump is an intermittent operation device, with relatively low catching efficiency, small suction range, large fluctuation of fish suction pressure, and easy to cause internal damage to fish, and is suitable for the conveyance of large-sized fish bodies. At present, researchers have also adopted some innovative methods to improve the catching efficiency of fish pumps and reduce the fish damage rate. For example:

[0004] The Chinese patent document with publication date April 4, 2023 and publication number CN115885943A discloses "a non-destructive continuous catching system and its working method", which uses a combination of a centrifugal pump and a water ring vacuum pump. First, the water ring vacuum pump evacuates the buffer tank, and then the centrifugal pump pumps water in the water receiving tank at the lower end of the fish-water separator to suck fish with a relatively constant fish suction pressure.

[0005] The Chinese patent document with publication date May 14, 2024 and publication number CN118020704A discloses "a fry entering the cabin buffer system for an aquaculture workboat", and provides a fry entering the cabin buffer system structure including a fish-water separator, a vacuum water diversion tank and a fry buffer tank to achieve low-damage catching and oxygen supply and temporary cultivation of fry.

[0006] In the above two patents, the fish do not pass through the running machinery throughout the process, avoiding mechanical damage and effectively achieving low-damage catching. However, both use a water ring vacuum pump, a centrifugal pump, an additional fish-water separation device and a water diversion device, with a complex system structure and operation process and high equipment cost. Summary of the Invention

[0007] The present invention provides a fish collecting device based on negative pressure non-contact fish suction. The fish collecting device is provided with a hollow fish collecting tank body, and the fish collecting tank body is provided with:

[0008] The fish suction pipeline, one end of which is connected to the fish inlet on one side of the top of the fish collecting tank body, and the other end of which is immersed in the fish-water mixing pool, and a fish suction valve is arranged on the fish suction pipeline;

[0009] The fish discharging pipeline, one end of which is connected to the fish outlet at the bottom of the fish collecting tank body, and the other end of which is connected to the grading device, the processing room or the fishing boat, and a fish discharging valve is arranged on the fish discharging pipeline;

[0010] The ventilation valve, which is arranged on the top of the fish collecting tank body, one end of which is connected to the inside of the fish collecting tank body, and the other end of which leads to the atmosphere directly;

[0011] The oxygen supply valve, which is arranged on the top of the fish collecting tank body, one end of which is connected to the inside of the fish collecting tank body, and the other end of which is connected to the oxygen generating device;

[0012] The low-position drain pipe, one end of which is connected to the first drain port at the bottom of the fish collecting tank body, and the other end of which is connected to the external water pool. A first valve, a water pump and a second valve are arranged in sequence on the low-position drain pipe. A drain branch pipe connected to the external water pool is arranged between the first valve and the water pump, and a third valve is arranged on the drain branch pipe;

[0013] The high-position drain pipe, one end of which is connected to the second drain port at the top of the fish collecting tank body, and the other end of which is connected to the low-position drain pipe between the water pump and the second valve, and a fourth valve is arranged on the high-position drain pipe;

[0014] The pressure sensor is arranged on the inner top surface of the fish collecting tank body;

[0015] The liquid level sensor is arranged in the fish collecting tank body.

[0016] Furthermore, a fish separating net is arranged at the first drain port.

[0017] Furthermore, the fish collecting device further includes a control host, and the control host is connected to the fish suction valve, the fish discharging valve, the ventilation valve, the oxygen supply valve, the first valve, the water pump, the second valve, the third valve, the fourth valve, the pressure sensor and the liquid level sensor.

[0018] Furthermore, the fish inlet and the second drain port are at the same height.

[0019] Furthermore, the water pump is a centrifugal water pump.

[0020] Further, the fish collecting tank body is composed of a tank body and a raised base. The tank body is made of fiberglass, with a thickness of 20 - 30 mm; the diameter of the tank body is between 2.5 - 4 m, the height is 2 - 3 m, and the total volume is not less than 10 m 3 , there is a maintenance hole at the top of the tank body, and the maintenance hole is hinged with a sealed flange cover plate. The material of the base is stainless steel.

[0021] Further, a transparent viewing window is provided on the side wall in the middle of the fish collecting tank body.

[0022] Further, a first multi-interface short pipe is provided at the top of the fish collecting tank body, and the first multi-interface short pipe is provided with signal transmission connectors for connecting a pressure sensor and a liquid level sensor.

[0023] Further, the low-position drain pipe is connected to the bottom of the fish collecting tank body through a second multi-interface short pipe, and a tubular liquid level gauge is connected between the second multi-interface short pipe and the first multi-interface short pipe;

[0024] A pressure gauge is provided on the low-position drain pipe between the water pump and the fish collecting tank body.

[0025] The fish collecting device provided by the present invention has the following advantages:

[0026] Low damage rate: The negative pressure non-contact fish suction method is adopted, and the fish body does not need to pass through high-speed rotating parts, reducing mechanical damage and being suitable for transporting large-sized fish bodies.

[0027] Higher efficiency: Continuous fish suction operation can be realized. By keeping the inflow and outflow consistent during fish suction, the pressure in the tank is kept constant. The larger the fish collecting tank body, the longer the continuous fish suction time.

[0028] Simple structure and low cost: The pressure is formed by pumping water with a centrifugal pump, without the need for a vacuum pump or an air compressor. The system structure and operation process are simplified, reducing equipment costs.

[0029] High degree of automation: The control host is connected to each valve, water pump and sensor, and automatic control of the fish suction, fish discharge and temporary culture processes can be realized.

[0030] Diverse functions: It has a temporary culture function, and oxygen can be introduced into the tank through an oxygen supply valve; a transparent viewing window is provided in the middle of the fish collecting tank body, facilitating the observation of the fish and water state in the tank; there is a maintenance hole at the top, which is convenient for maintenance and cleaning.

[0031] Strong applicability: The fish collecting tank body is made of fiberglass, corrosion-resistant and pressure-resistant, and the base is stainless steel, stable and durable, suitable for the large-scale facility aquaculture environment in the deep sea and far sea. Description of the Drawings

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0033] Figure 1 is the system schematic diagram of the present invention.

[0034] Figure 2 is the schematic diagram of step S1 of the present invention (pumping water into the fish collection device).

[0035] Figure 3 is the schematic diagram of step S2 of the present invention (pumping out water to form negative pressure).

[0036] Figure 4 is the schematic diagram of step S3 of the present invention (sucking fish).

[0037] Figure 5 is the schematic diagram of steps S4 to S5 of the present invention (discharging fish or temporarily raising fish).

[0038] Figure 6 is the reference schematic diagram during the derivation of the relationship between the pressure and liquid level changes in the fish collection device.

[0039] Figure 7 is the front view of the structure of the fish collection device.

[0040] Figure 8 is the top view of the structure of the fish collection device.

[0041] Figure 9 is the partial sectional view at the second connection of the multi-interface short pipe. Specific embodiments

[0042] In the following description, a large number of specific details are given to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some well-known technical features in the art are not described.

[0043] To thoroughly understand the present invention, detailed steps and detailed structures will be presented in the following description to illustrate the technical solutions of the present invention. The preferred embodiments of the present invention are described in detail as follows. However, in addition to these detailed descriptions, the present invention can also have other implementation manners.

[0044] The fish collection device based on negative pressure non-contact fish suction provided by the present invention has a hollow fish collection tank body 1 as the main body. The fish collection tank body 1 is composed of a tank body 11 and a raised base: the tank body is made of fiberglass, with a thickness of 20 - 30 mm, having the characteristics of anti-corrosion, pressure resistance, and low price; the diameter of the tank body is 2.5 - 4 m, the height is 2 - 3 m, and the total volume is not less than 10 m 3 . The base is made of 316L stainless steel and is composed of a fixing frame 12 and a bracket 13 arranged on the top of the fixing frame 12, providing bottom support for the tank body 11 to ensure the stable installation of the device.

[0045] An inspection hole 14 is provided at the top of the fish collection tank body 1, and the inspection hole is hinged with a sealed flange cover plate, facilitating the staff to enter the tank for inspection and cleaning. A transparent viewing window 15 (observation mirror) is provided on the middle side wall of the fish collection tank body 1, through which the state of fish and water in the tank can be observed in real time.

[0046] A first multi-interface short pipe 16 is also installed at the top of the fish collection tank body 1, which is hermetically connected to the top of the fish collection tank through a flange interface. The first multi-interface short pipe 16 is provided with signal connectors for connecting an oxygen supply valve 5, a pressure sensor 8, and a liquid level sensor 9, and can transmit the signals of the oxygen supply valve 5, the pressure sensor 8, and the liquid level sensor 9 to the control host.

[0047] The fish collection tank body 1 is further configured with multiple groups of functional pipelines and sensors. Specifically as follows:

[0048] Fish suction pipeline 2: One end is connected to the fish inlet on one side of the top of the fish collection tank body 1, and the other end is immersed in the fish-water mixing pool. A fish suction valve 21 is provided on the fish suction pipeline 2. When sucking fish, by opening the fish suction valve 21, the fish-water mixture is sucked into the fish collection tank body 1 by using the negative pressure in the tank.

[0049] Fish discharge pipeline 3: One end is connected to the fish outlet at the bottom of the fish collection tank body 1, and the other end can be connected to a grading device, a processing room, or a fishing boat. A fish discharge valve 31 is provided on the pipeline for discharging the fish-water mixture in the tank.

[0050] Ventilation valve 4: It is arranged at the top of the fish collection tank body 1, one end is connected to the inside of the tank body, and the other end leads directly to the atmosphere. The air pressure in the tank is balanced by switching the ventilation valve 4.

[0051] Oxygen supply valve 5: Also arranged at the top of the tank body, one end is connected to the inside of the tank body, and the other end is connected to an oxygen generation device, and oxygen can be introduced into the tank during the temporary cultivation process.

[0052] Low - level drain pipe 6: One end of the low - level drain pipe 6 is connected to the low - side drain port on the other side of the bottom of the fish - collecting tank body 1. The low - side drain port is provided with a fish - separating net 66 to prevent fish from running out of the tank during drainage. The other end of the low - level drain pipe 6 is connected to an external water tank. On the low - level drain pipe 6, a first valve 61, a water pump 62, and a second valve 63 are successively arranged in the water flow direction. A drain branch pipe 64 connected to the external water tank is arranged between the first valve 61 and the water pump 62, and a third valve 65 is arranged on the drain branch pipe 64. Among them, a fish - separating net 66 is provided at the low - side drain port to prevent fish from entering the drainage pipeline. Preferably, the water pump 62 is a centrifugal water pump, which can quickly form negative pressure in the tank for pumping operations.

[0053] As shown in Figures 7 - 9, the fish - collecting tank body 1 is provided with a second multi - interface short pipe 17 for connecting the low - level drain pipe 6. One end of the second multi - interface short pipe 17 is connected to the fish - collecting tank body 1 through a sealing ring flange 171, and the other end is connected to the water pump 62. A pressure gauge interface 173 is provided on the second multi - interface short pipe 17 for externally connecting a pointer - type pressure gauge. In addition, the first multi - interface short pipe 16 and the second multi - interface short pipe 17 are respectively provided with a first communicating vessel interface and a second communicating vessel interface 174. A transparent tubular liquid level gauge (not shown in the figure) is connected between the first communicating vessel interface and the second communicating vessel interface 174. A bracket 18 for fixing the tubular liquid level gauge is provided on the outer wall of the tank body 11. The tubular liquid level gauge is flush with the liquid level inside the tank, and the liquid level inside the tank can be observed with the naked eye.

[0054] High - level drain pipe 7: One end of the high - level drain pipe 7 is connected to the high - side drain port on the other side of the top of the fish - collecting tank body 1. The other end of the high - level drain pipe 7 is connected to the low - level drain pipe 6 between the water pump 62 and the second valve 63, and a fourth valve 71 is arranged on the high - level drain pipe 7.

[0055] Pressure sensor 8: It is arranged on the inner top surface of the fish - collecting tank body 1 and is connected through the first multi - interface short pipe 16 installed on the top surface of the fish - collecting tank, and is used for real - time monitoring of the pressure change in the tank.

[0056] Liquid level sensor 9: It is arranged on the inner top surface of the fish - collecting tank body 1 and is connected through the first multi - interface short pipe 16 installed on the top surface of the fish - collecting tank, and is used for monitoring the liquid level height in the tank.

[0057] This fish - collecting device further includes a control host, which is connected to the fish - sucking valve 21, the fish - discharging valve 31, the ventilation valve 4, the oxygen - supplying valve 5, the first valve 61, the water pump 62, the second valve 63, the third valve 65, the fourth valve 71, the pressure sensor 8, and the liquid level sensor 9, and realizes the automatic control of the entire fish - sucking, fish - discharging, and temporary - raising processes through a preset program.

[0058] The working process of the centrifugal pump non - contact fish - sucking and fish - collecting device of the present invention is introduced as follows:

[0059] A non-contact fish suction and collection method for a centrifugal pump, using the above fish suction and collection device, and comprising the following steps:

[0060] S1. Open the water pump 62, and water from the external water pool is pumped into the fish collection tank body 1 through the drainage branch pipe 64, the low-level drainage pipe 6, and the high-level drainage pipe 7, as Figure 2 shown. Step S1 specifically includes the following steps: Open the third valve 65, the fourth valve 71, and the ventilation valve 4, close the remaining valves, start the water pump 62 to pump water into the fish collection tank body 1 until the set water level H1 is reached. At this time, the air pressure P1 in the upper part of the fish collection tank body 1 is the same as the local atmospheric pressure, and the volume space is V1. Then close the water pump.

[0061] S2. Draw water from the low-level drainage pipe 6 to create a negative pressure inside the fish collection tank body 1; as Figure 3 shown. Step S2 specifically includes the following steps: Open the first valve 61 and the second valve 63, close the remaining valves, and start the water pump 62 to draw out the water in the fish collection tank body 1, thereby creating a negative pressure inside the tank.

[0062] S3. Use the negative pressure to open the fish suction pipeline 2 to implement fish suction, and the water drawing operation in step S2 continues to run, and keep the pressure sensor 8 at the set negative pressure value or negative pressure range, and the liquid level sensor 9 reaches the set liquid level value or liquid level range, as Figure 4 shown. Step S3 specifically includes the following steps: When the pressure in the fish collection tank body 1 is -35 kPa (any value within the range of -50 kPa to -30 kPa is acceptable), at this time, the corresponding liquid level height is H2, and the volume space of the air in the upper part of the fish collection tank body 1 is V2. Open the fish suction valve 21 to start sucking fish using the negative pressure. At the same time, the low-level drainage pipe 6 keeps draining water synchronously. Since the inflow and outflow of the fish suction pipeline 2 and the low-level drainage pipe 6 are consistent, the water level in the tank almost remains at the H2 position.

[0063] S4. When it is judged manually or by using a monitoring device that the fish-water mixture density in the fish collection tank body 1 is relatively high, close the water pump 62, stop the water drawing operation, and stop the fish suction of the fish suction pipeline 2, as Figure 5 shown. Step S4 specifically includes the following steps: When it is judged manually or by using a monitoring device that the fish-water mixture density in the fish collection tank body 1 is relatively high, close the water pump 62, the first valve 61, the second valve 63, and the fish suction valve 21.

[0064] S5. Use the fish collection tank body 1 for temporary cultivation, or directly discharge the fish through the fish discharge pipeline 3 without temporary cultivation. Continue as Figure 5As shown in the figure; Step S5 specifically includes the following steps: If temporary cultivation is required for a period of time, keep the ventilation valve 4 and the oxygen supply valve 5 open, close all other valves, and introduce compressed air or oxygen into the fish collection tank 1 to achieve temporary cultivation of the fish. When discharging the fish through the fish discharge pipeline 3, open the ventilation valve 4, open the oxygen supply valve 5, and then open the fish discharge valve 31 to discharge the fish to the corresponding equipment until all the fish are discharged completely.

[0065] See Figure 6 , before implementing this fish suction and collection method, first deduce the relationship between the pressure and liquid level changes in the fish collection tank 1: the initial water level is H1, and the initial air pressure is P1 = 1 atm (standard atmospheric pressure); when the water is pumped, the air pressure becomes P2, and the water level is H2; deduce the relationship between the liquid level change and the pressure change before and after the liquid level change in the fish collection tank 1: assume that the temperature is constant during the entire fish suction and collection operation process, the gas follows the ideal gas law, the liquid is incompressible, the fish collection tank 1 is rigid without deformation and has good sealing; the cross-sectional area S of the tank body of the fish collection tank 1 (which can be regarded as unchanged), and the columnar body with the total internal height H.

[0066] Deduction:

[0067] Initial gas volume: V1 = S(H - H1)

[0068] Gas volume after pumping: V2 = S(H - H2)

[0069] When the temperature is constant, the gas pressure is inversely proportional to the volume: P1V1 = P2V2

[0070] Substitute the volume expression: P1·S(H - H1) = P2·S(H - H2)

[0071] Obtain: H2 = H - P1(H - H1) / P2

[0072] △H = H1 - H2 = (H - H1)(P1 / P2 - 1)

[0073] Analysis: If the initial H1 = 0.8H and P2 = 0.7P1, that is, a negative pressure of 30 kPa, it is known that a pressure between -50 kPa and 30 kPa is beneficial for fish suction and causes less damage;

[0074] Liquid level change: △H = (H - H1)(P1 / P2 - 1) = 0.2H·(1 / 0.7 - 1) = 0.086H, that is, when a negative pressure of -30 kPa is formed, the liquid level change △H is 0.086H;

[0075] Similarly: when P2 = -35 kPa (i.e., P2 = 0.65P1), △H = 0.11H;

[0076] When P2 = -40 kPa (i.e., 0.6P1), △H = 0.13H;

[0077] When P2 = -45 kPa (i.e., 0.55P1), ΔH = 0.16H;

[0078] It can be seen from this that by using the water pump 62 to pump the water in the fish collection tank body 1, an appropriate negative pressure can be formed to suck fish when the liquid level changes little; when the fish suction pipeline 2 is opened, since the inflow rate is equal to the outflow rate, the pressure in the fish collection tank is constant, and continuous fish suction can be achieved. The larger the fish collection tank body 1 is, the longer the continuous fish suction time is. Stop fish suction until the fish-water mixing ratio is appropriate, and the "appropriate fish-water mixing ratio" is set according to additional criteria.

[0079] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and the equipment and structures not described in detail should be understood to be implemented in a common manner in the art; any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes, without departing from the scope of the technical solution of the present invention, which does not affect the essence of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A fish collection device based on negative pressure non-contact fish suction, characterized in that, The fish collecting device is provided with a hollow fish collecting tank body, and the fish collecting tank body is provided with: A fish suction pipeline, one end of the fish suction pipeline is connected to the fish inlet on one side of the top of the fish collecting tank body, the other end of the fish suction pipeline is immersed in the fish-water mixing pool, and a fish suction valve is arranged on the fish suction pipeline; A fish discharging pipeline, one end of the fish discharging pipeline is connected to the fish outlet at the bottom of the fish collecting tank body, the other end of the fish discharging pipeline is connected to a grading device, a processing room or a fishing boat, and a fish discharging valve is arranged on the fish discharging pipeline; A ventilation valve, the ventilation valve is arranged on the top of the fish collecting tank body, one end of the ventilation valve is connected to the inside of the fish collecting tank body, and the other end is directly communicated with the atmosphere; An oxygen supply valve, the oxygen supply valve is arranged on the top of the fish collecting tank body, one end of the ventilation valve is connected to the inside of the fish collecting tank body, and the other end is connected to an oxygen making device; A low-level drain pipe, one end of the low-level drain pipe is connected to the first drain port at the bottom of the fish collecting tank body, the other end of the low-level drain pipe is connected to an external water tank, a first valve, a water pump and a second valve are sequentially arranged on the low-level drain pipe, a drain branch pipe connected to the external water tank is arranged between the first valve and the water pump, and a third valve is arranged on the drain branch pipe; A high-level drain pipe, one end of the high-level drain pipe is connected to the second drain port at the top of the fish collecting tank body, the other end of the high-level drain pipe is connected to the low-level drain pipe between the water pump and the second valve, and a fourth valve is arranged on the high-level drain pipe; A pressure sensor, arranged on the inner top surface of the fish collecting tank body; A liquid level sensor, arranged inside the fish collecting tank body.

2. The fish aggregating device according to claim 1, characterized in that, A fish separating net is arranged at the first drain port.

3. The fish aggregating device according to claim 1, characterized in that The fish collecting device further includes a control host, and the control host is connected to the fish suction valve, the fish discharging valve, the ventilation valve, the oxygen supply valve, the first valve, the water pump and the second valve, the third valve, the fourth valve, the pressure sensor and the liquid level sensor.

4. The fish aggregating device according to claim 1, characterized in that, The water pump is a centrifugal water pump.

5. The fish aggregating device according to claim 1, wherein, The fish-aggregating tank body is composed of a tank body and a raised base. The tank body is made of glass fiber reinforced plastic with a thickness of 20 - 30 mm. The diameter of the tank body is between 2.5 - 4 m, the height is 2 - 3 m, and the total volume is not less than 10 m 3 . An inspection hole is provided at the top of the tank body, and a sealed flange cover plate is hinged to the inspection hole. The base is made of stainless steel.

6. The fish aggregating device according to claim 1, wherein A transparent viewing window is arranged on the middle side wall of the fish collecting tank body.

7. The fish aggregating device according to claim 1, wherein, A first multi-interface short pipe is arranged on the top of the fish collecting tank body, and the first multi-interface short pipe is provided with signal transmission connectors for connecting the pressure sensor and the liquid level sensor.

8. The fish aggregating device according to claim 7, wherein, The low-level drain pipe is connected to the bottom of the fish collecting tank body through a second multi-interface short pipe, and a tubular liquid level gauge is connected between the second multi-interface short pipe and the first multi-interface short pipe; A pressure gauge is arranged on the low-level drain pipe between the water pump and the fish collecting tank body.

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