A fry grading and conveying device based on fish swimming ability and a working method thereof

Abstract

The present application relates to a kind of fry grading conveying equipment based on fish swimming ability and its working method, comprising: the fish swimming grading bin of inclination, its highest end is connected to water flow, its inner cavity is divided into big fish swimming area, fish area, small fish swimming area in turn along water flow direction;Two fish transfer devices, each fish transfer device is equipped with an air cannon body, and two fish transfer devices are used to transfer big fish swimming area and small fish swimming area of fish swimming grading bin into corresponding air cannon body respectively;Wherein, air cannon body is built-in fry conveying support body, air cannon body one end is set as the fish end that is connected with conveying pipeline, and the other end is connected with compressed air source, and when conveying fish body, fish body is contained in fry conveying support body from air cannon body fish end by using airflow and pushes out.The present application utilizes fish size and swimming ability relationship curve to realize the nondestructive grading of fish size in combination with fish transfer device, and realizes long-distance fry conveying by using the cooperation of fry conveying support body and compressed air.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aquaculture, in particular to a fry grading and conveying device based on fish swimming ability and a working method thereof. BACKGROUND

[0002] With the continuous expansion of domestic fish fry breeding industry, the traditional fry grading and conveying method has many problems, such as high fry loss, low grading efficiency, and inability to achieve long-distance non-destructive conveying. The existing grading device usually adopts mechanical screening or manual operation, which is easy to cause physical damage to the fry, and is difficult to adapt to the grading needs of fry of different specifications. Therefore, an equipment capable of non-destructive grading according to fish swimming ability and achieving efficient conveying is urgently needed to improve the survival rate of fry and the efficiency of breeding. SUMMARY

[0003] The purpose of the present application is to provide a fry grading and conveying device based on fish swimming ability and a working method thereof to solve the defects in the prior art.

[0004] The purpose of the present application is achieved by a fry grading and conveying device based on fish swimming ability, comprising:

[0005] a fish swimming grading bin, which is arranged obliquely, with its highest end connected to a water flow in use, and its inner cavity divided into a large fish swimming area, a fish inlet area and a small fish swimming area in sequence along the direction of the water flow;

[0006] two fish turning devices, each of which is provided with an air cannon body, and the two fish turning devices are used to transfer the large fish swimming area and the small fish swimming area of the fish swimming grading bin into the corresponding air cannon bodies;

[0007] wherein the air cannon body is internally provided with a movable fry conveying holder for receiving and containing fish bodies, one end of the air cannon body is provided as a fish outlet end connected to a conveying pipeline, and the other end is connected to a compressed air source, and the fish bodies contained in the fry conveying holder are pushed out from the fish outlet end of the air cannon body by using air flow when conveying the fish bodies.

[0008] Further, the air cannon body is arranged obliquely, with the fish outlet end at the lower part and the air inlet end at the upper part.

[0009] Further, the fry conveying holder is composed of two limiting rubber plates and a connecting rod, the connecting rod is fixedly connected to the two limiting rubber plates, the limiting rubber plates are provided as circular plates, and the air cannon body is provided as a circular cylinder; when receiving fish bodies, the fry conveying holder is temporarily positioned by the contact between the edges of the limiting rubber plates and the inner wall of the air cannon body, and the fish turning device is opposite to the area between the two limiting rubber plates.

[0010] Furthermore, an air cannon cover is detachably mounted on the air inlet end of the air cannon body, and the air cannon cover is provided with a compressed air inlet for connecting to a compressed air source.

[0011] Furthermore, the fish rotating device comprises:

[0012] The fish turner is provided with a hollow seat, the water-facing side of the turner is provided with a water-passing side, and the water-removing side of the turner is provided with an opening for releasing the fish;

[0013] a transport shell seat, which is fixedly connected to and communicated with the side wall of the air cannon body and has an inlet for receiving the fish body;

[0014] A power unit, which is in driving connection with the fish turner;

[0015] Wherein, driven by the power unit, the fish turner has two switchable working positions:

[0016] One of the working positions of the fish rotating device is in the large fish swimming area / small fish swimming area of ​​the fish swimming and grading bin, for receiving large fish / small fish;

[0017] Another working position of the fish turner is outside the fish swimming classification chamber, and the dorsal opening of the fish turner is directly opposite to the inlet of the transfer shell seat, which is used for transferring fish bodies into the air cannon body.

[0018] Furthermore, two movable openings are opened on one side wall of the fish swimming and grading bin, and the two movable openings are respectively movably matched with two fish rotating devices. The fish rotating device includes a cylinder, the cylinder barrel of the cylinder is fixedly arranged, and its movable part is fixedly connected to the fish rotating device.

[0019] Furthermore, two rectifier tubes are installed in the fish swimming classification chamber, and mesh plates are provided on the water-facing side and the water-receiving side of the rectifier tube. The two rectifier tubes are respectively located upstream of the big fish swimming area and downstream of the small fish swimming area.

[0020] Furthermore, an openable and closable fish inlet funnel is connected to the upper part of the fish inlet area of ​​the fish swimming and grading bin.

[0021] Furthermore, the device also includes:

[0022] A water storage tank contains water, wherein the lowest end of the fish swimming and grading chamber faces downwardly toward the interior of the water storage tank;

[0023] A water inlet pipe, one end of which is connected to the water storage tank, and the other end of which is connected to the highest end of the fish swimming classification chamber;

[0024] A large-flow submersible pump based on frequency conversion control is installed in the water tank and connected to the water inlet pipe.

[0025] As another aspect of the present invention, a working method is proposed based on the above-mentioned device, comprising at least the following steps:

[0026] Preparation step: load the empty fish fry conveying carrier into the air cannon body;

[0027] Classification step: water flow is introduced into the fish swimming grading bin, a number of fish bodies are input into the fish input area of the fish swimming grading bin, the water flow is regulated, rectification is performed by the rectification pipe, fish are graded according to the fish size and swimming ability relationship curve, large-size fish bodies with strong swimming ability are gathered at the lower end surface of the upper rectification pipe, and small-size fish bodies are limited at the upper end surface of the lower rectification pipe, so that the large-size fish bodies are in the upper fish turning device, and the small-size fish bodies are in the lower fish turning device;

[0028] Transportation step: under the driving of each automatic force unit, the upper fish turning device transports the large-size fish bodies into the corresponding air cannon body, and the lower fish turning device transports the small-size fish bodies into the corresponding air cannon body;

[0029] Conveying step: when the fish fry enters the air cannon body, compressed air is used to push the fish fry conveying carrier into the conveying pipeline, and the fish fry conveying carrier and the graded fish fry are sent into the corresponding fish pool.

[0030] The beneficial effects of the present application are:

[0031] The problems of large loss and inability to long-distance nondestructive conveying of traditional fish fry grading devices are solved. The device controls water flow through a large-flow submersible pump and a rectification pipe, and grades fish fry by using a fish size and swimming ability relationship curve. Large-size fish fry is gathered at the upper part due to strong swimming ability, and small-size fish fry is limited at the lower part. The device is also equipped with a fish turning device and an air cannon system to realize nondestructive transfer and long-distance conveying of fish fry. The present application significantly improves the efficiency of fish fry grading and conveying, reduces fish fry damage, and has a wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a perspective view of the present application.

[0033] Figure 2 is a relationship diagram of the fish turning device and the air cannon body.

[0034] Figure 3 is another perspective view of the present application.

[0035] Figure 4 is a principle diagram of conveying fish bodies by using the air cannon body.

[0036] MARKING OF THE DRAWINGS:

[0037] Water tank 1, fish outlet 2, high-flow submersible pump 3, frame 4, water inlet pipe 5, fry conveying tray 6, limiting rubber plate 6a, connecting rod 6b, fish swimming and grading chamber 7, rectifier tube 8, filling funnel cover 9, fish inlet funnel 10, camera 11, air cannon cover 12, compressed air inlet 13, air cannon sealing buckle 14, air cannon body 15, fish transfer device 16, cylinder 17, and transfer shell seat 18. DETAILED DESCRIPTION

[0038] The following is a combination of the embodiments of the present invention Figure 1-4 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0039] like Figure 1-4 As shown, a fry grading and conveying device based on the swimming ability of fish is proposed, comprising:

[0040] The fish swimming classification chamber 7 is arranged obliquely, and water is introduced into its highest end when in use. Its inner cavity is divided into a large fish swimming area, a fish entry area, and a small fish swimming area in the direction of water flow. A rectifying area is also provided. In order to facilitate observation of the swimming status of large fish and small fish, the large fish swimming area and the small fish swimming area can be made of transparent material so that the swimming status of the fish can be observed from the outside;

[0041] Two fish transfer devices, each of which is equipped with a fixed air cannon body 15, that is, two air cannon bodies 15 are provided, and the two fish transfer devices are used to transfer the large fish swimming area and the small fish swimming area of ​​the fish swimming classification bin 7 to the corresponding air cannon body 15 respectively;

[0042] A water tank 1 is provided with water. The lowest end of the fish swimming and grading chamber 7 faces downwardly toward the interior of the water tank 1. Two pipes are fixed to one side wall of the water tank 1 as fish outlets 2. The two fish outlets 2 are connected to the lower ends of two air cannon bodies 15 through hoses, so as to transport the classified fish to a dedicated fish pond.

[0043] A water inlet pipe 5, one end of which is connected to the water storage tank 1, and the other end of which is connected to the highest end of the fish swimming classification chamber 7;

[0044] A high-flow submersible pump 3 based on frequency conversion control is installed in the water tank 1 and connected to the water inlet pipe 5;

[0045] The frame 4 is fixed in the water tank 1 , and the fish swimming classification chamber 7 is fixedly installed on the frame 4 .

[0046] Among them, the air cannon body 15 is equipped with a movable fish fry conveying tray 6 for receiving and accommodating fish bodies. One end of the air cannon body 15 is set as a fish outlet end connected to the conveying pipeline, and the other end is connected to the compressed air source. When conveying the fish bodies, the airflow is used to push the fish fry conveying tray 6 containing the fish bodies out of the fish outlet end of the air cannon body 15.

[0047] The air cannon body 15 is arranged obliquely, with its fish outlet end at the lower part and its air intake end at the upper part.

[0048] The above-mentioned fry conveying support body 6 is composed of two limiting rubber plates 6a and a connecting rod 6b, the connecting rod 6b is fixedly connected to the two limiting rubber plates 6a, the limiting rubber plates 6a are set as circular plates, and the air cannon body 15 is set as a cylinder; when receiving the fish body, the fry conveying support body 6 is temporarily positioned by relying on the contact between the edges of the two limiting rubber plates 6a and the inner wall of the air cannon body 15, and has a sealing effect to protect the fish body, and the fish turning device is facing the area between the two limiting rubber plates 6a; Figure 4 As shown, when transporting the classified fish bodies, the compressed gas impacts the limiting rubber plate 6a of the fry conveying tray 6, overcoming the friction between the edge of the limiting rubber plate 6a and the inner wall of the air cannon body 15, thereby pushing the fry conveying tray 6 out of the air cannon body 15, and delivering the fry conveying tray 6 and its fish bodies to the fish pond through the conveying pipe (through the fish outlet 2).

[0049] The air cannon cover 12 is detachably mounted on the air inlet end of the air cannon body 15, and the air cannon cover 12 is provided with a compressed air inlet 13 for connecting to a compressed air source; the air cannon cover 12 can be detachably mounted in many ways, such as using an air cannon sealing buckle 14 to lock the air cannon cover 12 to the upper air inlet end of the air cannon body 15 (when the air cannon cover 12 is removed, the air cannon sealing buckle 14 can be unlocked to unlock the air cannon cover 12), so that the air cannon cover 12 covers the upper air inlet end of the air cannon body 15, so that high-pressure gas can only enter the air cannon body 15 through the compressed air inlet 13 of the air cannon cover 12.

[0050] The above-mentioned fish rotating device comprises:

[0051] The fish turner 16 is configured as a hollow seat, the water-facing side of which is configured as a water-passing side, and the water-receiving side of which is configured as an opening for releasing fish;

[0052] a transport housing seat 18, which is fixedly connected to and communicates with the side wall of the air cannon body 15 and has an inlet for receiving the fish body;

[0053] The power unit is in transmission connection with the fish turner 16 .

[0054] Driven by the power unit, the fish spinner 16 has two switchable working positions:

[0055] One of the working positions of the fish rotating device 16 is in the large fish swimming area / small fish swimming area of ​​the fish swimming classification chamber 7, for receiving large fish / small fish;

[0056] like Figure 2 As shown, the other working position of the fish turner 16 is outside the fish swimming grading chamber 7, and the dorsal opening of the fish turner 16 is facing the entrance of the transfer shell seat 18, and also facing the area between the two limiting rubber plates 6a of the fry conveying tray 6. When the fish body is transferred into the air cannon body 15, the fish body can directly enter between the two limiting rubber plates 6a of the fry conveying tray 6.

[0057] In order to facilitate the movement of the fish turner 16 in and out of the fish swimming and grading chamber 7, two movable openings are opened on one side wall of the fish swimming and grading chamber 7, and the two movable openings are respectively coordinated with the horizontal movement of the two fish turners 16. The fish turning device includes a cylinder 17, and the cylinder barrel of the cylinder 17 is fixedly arranged (fixed on the frame 4), and its movable part is fixedly connected to the fish turner 16. The cylinder 17 can be set as a rodless cylinder. A magnet is fixed on the inner wall of the fish turner 16, and the fish turner 16 is fixed on the slider of the cylinder 17 by magnetic adsorption.

[0058] In addition, cameras 11 are installed in the large fish swimming area and the small fish swimming area of ​​the fish swimming classification warehouse 7 to monitor whether the fry group has completely entered the fish rotating device 16.

[0059] In order to rectify the water flow in the fish swimming grading chamber 7, effectively control the flow stability of the fish swimming area and prevent the fry from leaving the swimming area, the above-mentioned fish swimming grading chamber 7 is equipped with two rectifier tubes 8 (corresponding to the rectifier area), and the rectifier tube 8 is provided with mesh plates on the water-facing side and the water-receiving side. The two rectifier tubes 8 are respectively located upstream of the big fish swimming area and downstream of the small fish swimming area.

[0060] The water tank 1 is used to support the water demand of the fish swimming classification chamber 7 during circulation. The submersible pump 3 pumps water from the water tank 1 into the fish swimming classification chamber 7, passing through two rectifier tubes 8 and returning to the water tank. The rectifier tubes 8 are used to even out the inflow and outflow of water, effectively controlling the flow stability in the fish swimming area and preventing fry from leaving the swimming area. The high-flow submersible pump 3 is regulated by a frequency converter and the fish are graded according to a curve that relates fish size to swimming ability. Larger fish with stronger swimming abilities will gather at the lower end of the upper rectifier tube, while smaller fish cannot withstand the water flow and are confined to the upper end of the lower rectifier tube.

[0061] The upper part of the fish entry area of ​​the above-mentioned fish swimming grading warehouse 7 is connected to a closable fish entry funnel 10, and the upper port of the fish entry funnel 10 is installed with a closable filling funnel cover 9. The filling funnel cover 9 is used to cover the fish entry funnel 10. When the fry are poured into the fish entry funnel 10, the filling funnel cover 9 is immediately covered to fill the space in the funnel.

[0062] Based on the above equipment, a working method is proposed, including the following steps:

[0063] Preparation steps: Place the empty fry conveying tray 6 into the air cannon body 15, and lock the air cannon cover 12 on the upper port of the air cannon body 15 using the air cannon sealing buckle 14, so that the air cannon cover 12 covers the upper port of the air cannon body 15, and drive the two fish turners 16 to be in the fish swimming and grading chamber 7;

[0064] Classification steps: water is introduced into the fish swimming classification chamber 7, a number of fish are input into the fish inlet area of ​​the fish swimming classification chamber 7, the water flow is regulated, and the water is rectified by the rectifier tube 8. The fish are classified according to the relationship curve between fish size and swimming ability. Large fish with strong swimming ability will gather at the lower end surface of the upper rectifier tube 8, and small fish will be restricted by the impact of the water flow at the upper end surface of the rectifier tube 8. The large fish can be placed in the upper fish rotating device 16, and the small fish can be placed in the lower fish rotating device 16.

[0065] Transfer step: Under the drive of each power unit (cylinder 17), the fish transfer device 16 carries the fish of corresponding specifications and moves out of the fish swimming and grading chamber 7, so that the dorsal opening of the fish transfer device 16 is directly opposite to the entrance of the transfer shell seat 18, and the dorsal opening of the fish transfer device 16 is obliquely downwardly aligned with the entrance of the transfer shell seat 18, and is also directly opposite to the area between the two limiting rubber plates 6a of the fry conveying tray 6, and the fish body is driven by its own weight to fall directly between the two limiting rubber plates 6a of the fry conveying tray 6;

[0066] The upper fish transfer device 16 transfers large-sized fish to the corresponding air cannon body 15, and the lower fish transfer device 16 transfers small-sized fish to the corresponding air cannon body 15;

[0067] Conveying step: using compressed air to push the fry conveying tray 6 into the conveying pipe, the fry conveying tray 6 and the graded fry are sent to the corresponding fish ponds, that is, the big fish and the small fish are sent to two different ponds respectively.

[0068] More specifically, compressed air enters the air cannon body 15 through the compressed air inlet 13, and uses the compressed gas to impact the limiting rubber plate 6a of the fry conveying tray 6, overcoming the friction between the edge of the limiting rubber plate 6a and the inner wall of the air cannon body 15, thereby pushing the fry conveying tray 6 out of the air cannon body 15, and sending the fry conveying tray 6 and the fish bodies into the fish pond through the conveying pipe (through the fish outlet 2).

[0069] like Figure 3As shown, when the fry are transported, the fish turner 16 needs to be reset, that is, the fish turner 16 needs to be moved into the fish swimming and grading chamber 7; the user needs to open the air cannon sealing buckle 14 and install the fry transporting bracket 6 inside and then close the air cannon cover 12 so that subsequent compressed air can enter from the compressed air inlet 13.

[0070] During the breeding process, putting large fish and small fish together will cause the large fish to snatch food from the small fish. Individual differences are inevitable during the breeding process, so it is necessary to regularly separate the large fish and small fish and transport them to corresponding fish ponds. It is worth mentioning that the large fish and small fish mentioned in this invention are simplified nouns, specifically, fish that meet the specifications for the next stage and fish that do not meet the specifications, respectively.

[0071] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "front", "back", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention; in the present invention, it should also be noted that the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, an integrally formed connection, a mechanical connection, or an indirect connection through an intermediate connecting component, and the specific meaning of the terms in this utility model can be understood according to the specific circumstances.

[0072] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description. It is intended that all variations within the meaning and range of equivalents of the claims be embraced herein, and any reference signs in the claims should not be construed as limiting the claims to which they relate.

[0073] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A fry grading and conveying device based on the swimming ability of fish, characterized in that: include: The fish swimming classification chamber (7) is arranged obliquely, and water flows into the highest end thereof when in use, and the inner cavity thereof is divided into a large fish swimming area, a fish entry area, and a small fish swimming area in sequence along the direction of the water flow; Two fish transfer devices, each of which is equipped with an air cannon body (15), and the two fish transfer devices are used to transfer the large fish swimming area and the small fish swimming area of ​​the fish swimming classification chamber (7) to the corresponding air cannon body (15); The air cannon body (15) is equipped with a movable fry conveying support (6) for receiving and accommodating fish bodies. One end of the air cannon body (15) is set as a fish outlet end connected to a conveying pipeline, and the other end is connected to a compressed air source. When the fish bodies are conveyed, the fry conveying support (6) containing the fish bodies is pushed out from the fish outlet end of the air cannon body (15) by utilizing air flow. The air cannon body (15) is arranged obliquely, with its fish outlet end at the bottom and its air inlet end at the top. The fry conveying support (6) is composed of two limiting rubber plates (6a) and a connecting rod (6b). The connecting rod (6b) is fixedly connected to the two limiting rubber plates (6a). The limiting rubber plates (6a) are configured as circular plates, and the air cannon body (15) is configured as a cylinder. When receiving a fish body, the fry conveying support (6) is temporarily positioned by relying on the contact between the edge of the limiting rubber plate (6a) and the inner wall of the air cannon body (15).

2. The fry grading and conveying device based on the swimming ability of fish according to claim 1 is characterized in that: An air cannon cover (12) is detachably mounted on the air inlet end of the air cannon body (15), and a compressed air inlet (13) for connecting to a compressed air source is provided on the air cannon cover (12).

3. The fry grading and conveying device based on the swimming ability of fish according to claim 1, characterized in that: The fish rotating device comprises: The fish turner (16) is configured as a hollow seat, the water-facing side of which is configured as a water-passing side, and the water-receiving side of which is configured as an opening for releasing fish; A transport shell seat (18) is fixedly connected to and communicates with the side wall of the air cannon body (15), and has an inlet for receiving a fish body; A power unit, which is in transmission connection with the fish turner (16); Wherein, driven by the power unit, the fish turner (16) has two switchable working positions: One of the working positions of the fish rotating device (16) is located in the large fish swimming area / small fish swimming area of ​​the fish swimming classification chamber (7), and is used to receive large fish / small fish; Another working position of the fish transfer device (16) is outside the fish swimming classification chamber (7), and the backwater side opening of the fish transfer device (16) faces the inlet of the transfer shell seat (18), and is used for transferring fish bodies into the air cannon body (15).

4. The fry grading and conveying device based on the swimming ability of fish according to claim 3, characterized in that: Two movable openings are provided on one side wall of the fish swimming classification chamber (7), and the two movable openings are respectively movably matched with two fish rotating devices (16). The fish rotating device includes a cylinder (17), the cylinder barrel of the cylinder (17) is fixedly arranged, and the movable portion thereof is fixedly connected to the fish rotating device (16).

5. The fry grading and conveying device based on the swimming ability of fish according to claim 4, characterized in that: The fish swimming classification chamber (7) is equipped with two rectifier tubes (8), and mesh plates are provided on the water-facing side and the water-receiving side of the rectifier tube (8). The two rectifier tubes (8) are respectively located upstream of the large fish swimming area and downstream of the small fish swimming area.

6. The fry grading and conveying device based on the swimming ability of fish according to claim 1, characterized in that: The upper portion of the fish inlet area of ​​the fish swimming classification chamber (7) is connected to a fish inlet funnel (10) that can be opened and closed.

7. The fry grading and conveying device based on the swimming ability of fish according to any one of claims 1 to 6, characterized in that: Also includes: A water storage tank (1) contains water, and the lowest end of the fish swimming classification chamber (7) faces downwardly toward the interior of the water storage tank (1); A water inlet pipe (5), one end of which is connected to the water storage tank (1), and the other end of which is connected to the highest end of the fish swimming classification chamber (7); A high-flow submersible pump (3) based on variable frequency control is installed in a water storage tank (1) and connected to a water inlet pipe (5).

8. A working method based on the fish fry grading and conveying device according to claim 5, characterized in that: At least the following steps are included: Preparation step: loading the empty fry conveying tray (6) into the air cannon body (15); Classification steps: introducing water into the fish swimming classification chamber (7), inputting a number of fish bodies into the fish inlet area of ​​the fish swimming classification chamber (7), regulating the water flow, rectifying the water using the rectifier tube (8), and classifying the fish according to the relationship curve between the fish size and the swimming ability. The large-sized fish bodies with stronger swimming ability will gather at the lower end surface of the upper rectifier tube (8), and the small-sized fish bodies will be restricted by the impact of the water flow at the upper end surface of the rectifier tube (8), so that the large-sized fish bodies are placed in the upper fish rotating device (16) and the small-sized fish bodies are placed in the lower fish rotating device (16); Transfer step: driven by the respective power units, the upper fish transfer device (16) transfers the large-sized fish body to the corresponding air cannon body (15), and the lower fish transfer device (16) transfers the small-sized fish body to the corresponding air cannon body (15); Conveying step: After the fry enters the air cannon body (15), compressed air is used to push the fry conveying support (6) into the conveying pipe, and the fry conveying support (6) and the graded fry are conveyed into the corresponding fish pond together.

Images