Plankton net with in-situ separation sampling device

Abstract

The invention discloses a plankton net with an in-situ separating and sampling device, which belongs to the technical field of marine ecological monitoring equipment and comprises a plankton net and the in-situ separating and sampling device. The in-situ separation sampling device comprises a connecting piece and a separation sampling piece; the separating and sampling part comprises a separating cylinder and a sampling cylinder, a separating cavity is formed in the separating cylinder, and a regular conical screen which is inclined and lowered towards the inclined position of the sampling cylinder is mounted in the separating cavity. Due to the inclined design of the regular conical screen, under the action of gravity and water flow, small fish eggs quickly pass through the regular conical screen and enter the next stage of separation barrel, and large larvae cannot pass through the regular conical screen and are intercepted to enter the sampling barrel, so that in-situ physical separation is realized; the inverted-cone-shaped flow guide seat guides water flow to intensively impact the highest position of the screen through the flow guide opening, the overall screening effect is further improved, the blocking risk of the screen can be reduced, the separation efficiency is improved, samples are prevented from being mixed due to turbulent flow in the separation process, and the survival rate of the samples to be detected is improved.

Description

Technical Field

[0001] This invention relates to the field of marine ecological monitoring equipment technology, specifically to a planktonic net equipped with an in-situ separation and sampling device. Background Technology

[0002] Current methods for marine planktonic sampling primarily rely on large planktonic nets (such as trawls or vertical trawls). The workflow is as follows: trapping mixed planktonic populations (including fish eggs, larvae, and other planktonic organisms) using nets → transferring samples to the laboratory after trawls → separating target samples (such as fish eggs and larvae) through subsequent processing such as filtration, centrifugation, or sieving. This traditional method generally suffers from the following problems: Low survival rate of larvae and juveniles: After sampling, multiple mechanical filtrations are required (such as filter screen squeezing and centrifugation). Larvae and juveniles are easily damaged or even die due to collisions, squeezing or water flow impacts, which affects the accuracy of subsequent survival rate statistics and ecological research. Large counting and classification errors: Fish eggs (tiny, transparent or translucent) and larvae (tiny living organisms) have small morphological differences in mixed samples, and are difficult to completely separate by conventional sieving after mixing, which leads to easy omissions or misclassifications during laboratory counting. The process is cumbersome and inefficient: the traditional process requires multiple steps of "sampling → recycling → laboratory processing", which cannot directly separate the target sample in situ at sea. It is time-consuming, labor-intensive and dependent on professional laboratory equipment, making it difficult to meet the needs of high-frequency and large-scale ecological monitoring. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a plankton net with an in-situ separation sampling device. Through the combined design of "plankton net + in-situ separation sampling device", fish eggs and larvae are directly separated during trawling, realizing "sampling and separation". It takes into account both flexibility and sealing, and is used to solve the problems of fish eggs and larvae mixing, high mechanical damage rate and low operation efficiency in traditional plankton sampling.

[0004] To achieve the above objectives, the present invention provides the following technical solution: A planktonic net equipped with an in-situ separation and sampling device includes a planktonic net and an in-situ separation and sampling device that is detachably installed at the bottom of the planktonic net; The in-situ separation sampling device includes a set of connectors and multiple sets of separation sampling components that can be connected end to end. The separation sampling components include a separation cylinder located at the center and a sampling cylinder coaxially installed on the outside of the separation cylinder. The separation cylinder has a separation chamber inside, and a positive conical screen that is inclined downwards towards the sampling cylinder is installed in the separation chamber. A vertical rod connects the positive conical screen to an inverted conical guide seat that is detachably installed on the inner wall of the separation chamber. A guide port that guides the flow to the highest point of the positive conical screen is opened at the center of the inverted conical guide seat.

[0005] By adopting the above scheme, the inclined design of the conical screen utilizes gravity and water flow to allow smaller fish eggs to quickly pass through the conical screen into the next separation cylinder, while larger larvae and juveniles are intercepted and enter the sampling cylinder because they cannot pass through the conical screen, thus achieving in-situ physical separation. The inverted conical guide seat guides the water flow through the guide port to concentrate and impact the highest point of the screen, further improving the overall screening effect, reducing the risk of screen blockage, improving separation efficiency, avoiding sample mixing due to turbulence during the separation process, and improving the survival rate of the sample to be tested.

[0006] As a preferred embodiment of a planktonic net with an in-situ separation and sampling device, the inverted conical guide seat is threadedly installed on the inner wall of the separation chamber. A horizontal bar is connected inside the guide port to assist the inverted conical guide seat in rotating with leverage. The top of the vertical bar is connected to the bottom of the horizontal bar. The threaded connection facilitates the quick installation and removal of the guide seat and makes it easy to replace different models of conical screens. The combination of the horizontal bar and the vertical bar allows the horizontal bar to be rotated directly when the guide seat is rotated, thus facilitating the installation or removal of the guide seat with leverage.

[0007] As a preferred embodiment of a plankton net with an in-situ separation sampling device, the side wall of the separation chamber has multiple separation ports 1 arranged in a circumferential array near the location of the conical screen. The circumferential array distribution expands the collection range of fish eggs and increases the separation throughput. Furthermore, all separation ports 1 are located at the lowest point of the conical screen, ensuring that larvae and juveniles directly enter the separation ports 1, reducing their residence time in the separation chamber and lowering the risk of secondary contamination. Multiple arc-shaped baffles arranged parallel to the vertical rod are connected between the conical screen and the inverted conical guide seat. Each arc-shaped baffle is located between two adjacent separation ports 1. The arc-shaped baffles effectively prevent larvae and juveniles from accumulating at this point, making the separation of larvae and juveniles smoother.

[0008] As a preferred embodiment of a plankton net with an in-situ separation sampling device, the sampling tube has a sampling chamber inside, and a horizontally set screen is installed at the bottom of the sampling chamber. Multiple separation ports II, which are the same size and position as separation port I, are opened on the side of the sampling chamber facing the separation chamber. The precise correspondence between separation ports II and separation port I ensures the smooth transfer of fish eggs from the separation chamber to the sampling chamber and avoids leakage. The horizontal screen can intercept larvae and juvenile fish, and the remaining water is discharged from the horizontal screen to the outside of the sampling chamber, improving the purity of the final fish egg sample.

[0009] In a preferred embodiment of a planktonic net equipped with an in-situ separation and sampling device, a horizontally arranged mounting platform is connected to the outer wall of the separation cylinder. The mounting platform has multiple slots arranged in a circumferential array. The top of the sampling cylinder is connected to multiple plugs arranged in a circumferential array that can be inserted into the slots from bottom to top. A clamp is installed above the mounting platform, which is installed and removed by the plugs via threads. The plug-in design of the slots and plugs enables the separation cylinder and the sampling cylinder to be quickly assembled, facilitating on-site replacement or maintenance. The clamp tightens the plugs with threads to ensure reliable connection.

[0010] As a preferred embodiment of a planktonic net equipped with an in-situ separation sampling device, the surface of the clamp is provided with multiple uniformly distributed clearance grooves I, and the surface of the mounting platform is provided with multiple uniformly distributed clearance grooves II that correspond vertically to the clearance grooves. The clearance grooves I and II are used to discharge excess material from the horizontal screen to the outside of the sampling chamber.

[0011] As a preferred embodiment of a planktonic net equipped with an in-situ separation sampling device, the planktonic net includes a net body and a mesh nozzle installed at the center of the bottom of the net body; the top of the net body is the mesh opening, and an elastic rope that can change the size of the opening is installed at the edge of the mesh opening. The elastic rope can flexibly adjust the opening of the mesh opening to adapt to the sampling needs of different water layers or flow velocities.

[0012] In a preferred embodiment of a plankton net equipped with an in-situ separation and sampling device, a main traction rope is provided at the top of the net. The main traction rope is connected to multiple circumferentially distributed auxiliary traction ropes through a ball knot. The main and auxiliary traction ropes provide a stable drag force for the plankton net, while the ball knot disperses the tension to prevent excessive local stress and damage at the net opening. All auxiliary traction ropes pass through rope loops installed on the outside of the net and are finally led to the in-situ separation and sampling device. The rope loops fix the position of the auxiliary traction ropes to prevent the ropes from getting tangled in the net during hauling and to ensure that the traction force is evenly transmitted to the net opening. The auxiliary traction ropes leading to the in-situ separation and sampling device can be used to further pull the separation and sampling device to prevent it from swinging with the water flow and affecting the separation effect.

[0013] In a preferred embodiment of a plankton net equipped with an in-situ separation and sampling device, the connector includes a connecting sleeve. The top of the connecting sleeve is connected to the inner wall of the net nozzle via threads, and the bottom of the connecting sleeve is connected to the inner wall of the separation chamber via threads. The double-threaded structure of the connecting sleeve enables quick assembly and disassembly of the plankton net and the in-situ separation and sampling device, facilitating individual maintenance or replacement of components. The side wall of the connecting sleeve is connected to multiple traction ears equal in number to the auxiliary traction ropes. The traction ears are provided with traction grooves for suspending the auxiliary traction ropes. The traction ears and traction grooves fix the auxiliary traction ropes to the side wall of the connector, further stabilizing the position of the separation and sampling device, preventing it from deviating from the center of the net due to water flow impact, and ensuring the stability of the separation effect.

[0014] The beneficial effects of this invention are: 1. Preservation of sample viability: In-situ physical separation avoids the mechanical damage of traditional filtration, significantly improving the survival rate of juvenile fish; 2. Improve classification accuracy: Fish eggs and larvae are separated during the sampling process, eliminating counting errors caused by mixing and improving classification accuracy; 3. Simplified operation process: It realizes "sampling and separation" without returning to the laboratory for processing, which greatly shortens the monitoring cycle and is suitable for high-frequency marine ecological surveys; 4. Better separation effect: The inverted cone-shaped guide seat guides the water flow through the guide port to concentrate and impact the highest point of the screen, further improving the overall screening effect, reducing the risk of screen clogging and improving separation efficiency; 5. Modular design: The detachable sampling components can be disassembled and assembled in sections, which facilitates maintenance, replacement or adaptation to different water layer sampling needs; 6. Strong structural stability: The design of the traction system ensures that the device maintains accurate positioning and reliable separation effect in complex ocean currents. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A three-dimensional view of a planktonic network equipped with an in-situ separation and sampling device; Figure 2 A three-dimensional diagram of a planktonic web; Figure 3 A three-dimensional view of the in-situ separation sampling device; Figure 4 A three-dimensional view of the connector; Figure 5 A three-dimensional arrangement of three sets of separate sampling components connected end to end. Figure 1 ; Figure 6 A three-dimensional arrangement of three sets of separate sampling components connected end to end. Figure 2 ; Figure 7 for Figure 5 The main view; Figure 8 for Figure 5 Top view; Figure 9 for Figure 5 A bottom view; Figure 10 for Figure 7 Sectional view at point AA; Figure 11 for Figure 7 Sectional view at point BB; Figure 12 Exploded view of the separated sample; Figure 13 for Figure 12 A magnified view of a section at point C; Figure 14 for Figure 13 A three-dimensional view of the symmetrical conical screen and the inverted conical guide seat assembly.

[0017] The diagram is labeled as follows: 1-Plankton net; 11-Net body; 12-Net opening; 13-Elastic rope; 14-Net nozzle; 15-Main traction rope; 16-Knot; 17-Auxiliary traction rope; 18-Rope loop; 2-Connector; 21-Connecting sleeve; 22-Traction ear; 23-Traction groove; 3-Separation sampling component; 31-Separation cylinder; 32-Separation chamber; 33-Positive conical screen; 34-Vertical rod; 35-Inverted conical guide seat; 36-Guide port; 37-Horizontal rod; 38-Separation port one; 39-Sampling cylinder; 310-Sampling chamber; 311-Horizontal screen; 312-Separation port two; 313-Mounting platform; 314-Slot; 315-Allowing groove two; 316-Plug; 317-Tightening clamp; 318-Allowing groove one; 319-Arc-shaped baffle. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] like Figure 1 As shown, a plankton net equipped with an in-situ separation sampling device is provided for marine fishery resource surveys, fish egg and larval population monitoring, and marine ecological environment assessment. Specifically, it includes a plankton net 1 and an in-situ separation sampling device that is detachable and installed at the bottom of the plankton net 1.

[0020] like Figure 2 As shown, the planktonic net 1 includes a net body 11 and a mesh nozzle 14 installed at the center of the bottom of the net body 11; the top of the net body 11 is a mesh opening 12, and an elastic rope 13 that can change the size of the opening is installed at the edge of the mesh opening 12. The elastic rope 13 can flexibly adjust the opening of the mesh opening 12 to adapt to the sampling needs of different water layers or flow rates.

[0021] Continue as Figure 2As shown, a main traction rope 15 is provided at the top of the net body 11. The main traction rope 15 is connected to three circumferentially distributed auxiliary traction ropes 17 through a ball knot. The main traction rope 15 and the auxiliary traction ropes 17 provide a stable drag force for the plankton net 1, and at the same time, the ball knot disperses the tension to avoid excessive local stress and damage to the net opening 12. All auxiliary traction ropes 17 pass through the rope loops 18 installed on the outside of the net body 11 and are finally led to the in-situ separation sampling device. The rope loops 18 fix the position of the auxiliary traction ropes 17 to prevent the ropes from getting tangled in the net body 11 during the trawling process and to ensure that the traction force is evenly transmitted to the net opening 12. The auxiliary traction ropes 17 leading to the in-situ separation sampling device can be used to further pull the separation sampling device to prevent it from swinging with the water flow and affecting the separation effect.

[0022] like Figure 3 As shown, the in-situ separation sampling device includes a set of connectors 2 and three sets of separation sampling components 3 that can be connected end to end. The three sets of separation sampling components 3 together constitute a three-stage separation sampling device 3, which realizes the precise screening of fish eggs and larvae.

[0023] like Figure 4 As shown, the connector 2 includes a connecting sleeve 21. The top of the connecting sleeve 21 is connected to the inner wall of the mesh nozzle 14 by a thread, and the bottom of the connecting sleeve 21 is connected to the inner wall of the separation chamber 32 by a thread. The double-threaded structure of the connecting sleeve 21 enables quick assembly and disassembly of the planktonic net 1 and the in-situ separation sampling device, facilitating individual maintenance or replacement of components. The side wall of the connecting sleeve 21 is connected to three traction ears 22, the same number as the auxiliary traction rope 17. The traction ears 22 are provided with traction grooves 23 for suspending the auxiliary traction rope 17. The traction ears 22 and the traction grooves 23 fix the auxiliary traction rope 17 to the side wall of the connector 2, further stabilizing the position of the separation sampling device and preventing it from deviating from the center of the net body 11 due to water flow impact, thus ensuring the stability of the separation effect.

[0024] like Figures 5 to 10As shown, the separation sampling component 3 includes a separation cylinder 31 located at the center and a sampling cylinder 39 coaxially installed on the outside of the separation cylinder 31. A separation cavity 32 is provided inside the separation cylinder 31. A positive conical screen 33 is installed in the separation cavity 32, which is inclined downward towards the sampling cylinder 39. A vertical rod 34 connects the positive conical screen 33 to an inverted conical guide seat 35 that is detachably installed on the inner wall of the separation cavity 32. A guide port 36 is provided at the center of the inverted conical guide seat 35 to guide the flow to the highest point of the positive conical screen 33. The inclined design of the conical screen 33 utilizes gravity and water flow to allow smaller fish eggs to quickly pass through the conical screen 33 and enter the next stage separation cylinder 31, while larger fry and larvae are intercepted and enter the sampling cylinder 39 because they cannot pass through the conical screen 33, thus achieving in-situ physical separation. The inverted conical guide seat 35 guides the water flow through the guide port 36 to concentrate and impact the highest point of the screen, further improving the overall screening effect, reducing the risk of screen blockage, improving separation efficiency, avoiding sample mixing due to turbulence during separation, and improving the survival rate of the sample to be tested.

[0025] like Figure 10 , Figure 14 As shown, the inverted conical guide seat 35 is threadedly installed on the inner wall of the separation chamber 32. A horizontal bar 37 is connected inside the guide port 36 to assist the inverted conical guide seat 35 in rotating by lever. The top of the vertical bar 34 is connected to the bottom of the horizontal bar 37. The threaded connection facilitates the quick installation and removal of the guide seat and makes it easy to replace different models of conical screens 33. The combination of the horizontal bar 37 and the vertical bar 34 allows the horizontal bar 37 to be rotated directly when the guide seat is rotated, thus facilitating the installation or removal of the guide seat by lever.

[0026] like Figure 11 As shown, four separation ports 38 are provided on the side wall of the separation chamber 32, which are located near the conical screen 33 and arranged in a circumferential array. The circumferential array distribution expands the collection range of fish eggs and increases the separation throughput. All separation ports 38 are located at the lowest point of the conical screen 33, ensuring that larvae and juveniles can directly enter the separation ports 38, reducing their residence time in the separation chamber 32 and reducing the risk of secondary mixing. Multiple arc-shaped baffles 319 are connected between the conical screen 33 and the inverted conical guide seat 35 and are arranged parallel to the vertical rod 34. Each arc-shaped baffle 319 is located between two adjacent separation ports 38. The arc-shaped baffles 319 can effectively prevent larvae and juveniles from accumulating at this point, making the separation of larvae and juveniles smoother.

[0027] like Figure 10As shown, the sampling tube 39 has a sampling chamber 310 inside. A horizontally set horizontal screen 311 is installed at the bottom of the sampling chamber 310. Four separation ports 312 of the same size and position as the separation port 38 are opened on the side of the sampling chamber 310 facing the separation chamber 32. The precise correspondence between the separation ports 312 and the separation ports 38 ensures the smooth transfer of fish eggs from the separation chamber 32 to the sampling chamber 310 and avoids leakage. The horizontal screen 311 can intercept juvenile fish, and the remaining water is discharged from the horizontal screen 311 to the outside of the sampling chamber 310, thereby improving the purity of the final fish egg sample.

[0028] like Figures 12 to 13 As shown, a horizontally arranged mounting platform 313 is connected to the outer wall of the separating cylinder 31. The mounting platform 313 has four circumferentially arrayed slots 314. The top of the sampling cylinder 39 is connected to multiple circumferentially arrayed plugs 316 that can be inserted into the slots 314 from bottom to top. A clamp 317 is installed above the mounting platform 313, which can be disassembled and installed by threads with the plugs 316. The insertion design of the slots 314 and the plugs 316 enables the quick assembly of the separating cylinder 31 and the sampling cylinder 39, which is convenient for on-site replacement or maintenance. The clamp 317 presses the plugs 316 with threads to ensure the reliability of the connection.

[0029] like Figure 12 As shown, the surface of the clamp 317 is provided with eight evenly distributed clearance grooves 318, and the surface of the mounting platform 313 is provided with eight evenly distributed clearance grooves 315 that correspond to the clearance grooves above and below. The clearance grooves 318 and 315 are used to discharge excess material from the horizontal screen 311 to the outside of the sampling chamber 310.

[0030] Working principle of the invention: Sampling stage: The plankton net 1 is lowered to the target water layer by a tow rope. The net opening 12 is opened by the tension rope 13. During the dragging process, mixed plankton (including fish eggs and larvae) enter the net body 11 with the water flow.

[0031] In-situ separation stage: After the mixture flows through the net body 11, it reaches the mesh nozzle 14 and enters the separation cylinder 31 of the in-situ separation sampling device through the connector 2; the water flow carries the sample and impacts the inverted conical guide seat 35, and guides the water flow through the guide port 36 to concentrate and impact the highest point of the screen. The sample flows from the highest point of the conical screen 33 to the surrounding low points. At this time, smaller fish eggs (usually 1-5 mm in diameter) flow downward through the screen holes (<6 mm) and then enter the next stage separation chamber 32; while larger larvae (usually >5 mm in body length) are intercepted in the separation chamber 32 because they cannot pass through the conical screen 33. They then enter the sampling chamber 310 through the first separation port 38 and the second separation port 312, and then flow into the horizontal screen 311 of the sampling cylinder 39, and finally gather at the bottom of the sampling chamber 310. At this time, the water is discharged from the bottom of the horizontal screen 311.

[0032] Results: After trawl, the separation tube 31 contains intact larval and juvenile fish samples (without mechanical damage and high survival rate), while the sampling tube 39 contains pure fish egg samples (without larval or juvenile fish contamination). Almost no additional filtration is required, and the samples can be directly used for laboratory counting, classification, or survival experiments.

[0033] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A plankton net equipped with an in-situ separation and sampling device, comprising a plankton net and an in-situ separation and sampling device detachably installed at the bottom end of the plankton net; characterized in that, The in-situ separation sampling device includes a set of connectors and multiple sets of separation sampling components that can be connected end to end. The separation sampling component includes a separation cylinder located at the center and a sampling cylinder coaxially installed on the outside of the separation cylinder. The separation cylinder has a separation cavity inside. A positive conical screen that tilts downwards towards the sampling cylinder is installed in the separation cavity. A vertical rod connects the positive conical screen to an inverted conical guide seat that is detachably installed on the inner wall of the separation cavity. A guide port that guides the flow to the highest point of the positive conical screen is opened at the center of the inverted conical guide seat.

2. The planktonic net equipped with an in-situ separation and sampling device according to claim 1, characterized in that, The inverted conical guide seat is threaded onto the inner wall of the separation chamber. A horizontal bar is connected inside the guide port to assist the inverted conical guide seat in rotating by force. The top of the vertical bar is connected to the bottom of the horizontal bar.

3. The planktonic net equipped with an in-situ separation and sampling device according to claim 1, characterized in that, The side wall of the separation chamber is provided with multiple separation ports 1 that are close to the location of the conical screen and are arranged in a circumferential array. Multiple arc-shaped baffles that are parallel to the vertical rod are connected between the conical screen and the inverted conical guide seat. Each arc-shaped baffle is located between two adjacent separation ports 1.

4. The planktonic net equipped with an in-situ separation and sampling device according to claim 3, characterized in that, The sampling tube has a sampling cavity inside, and a horizontally arranged screen is installed at the bottom of the sampling cavity. Multiple separation ports of the same size and position as separation port one are opened on the side of the sampling cavity facing the separation cavity.

5. The planktonic net with an in-situ separation and sampling device according to claim 1, characterized in that, A horizontally arranged mounting platform is connected to the outer wall of the separation cylinder. The mounting platform has multiple slots arranged in a circumferential array. The top of the sampling cylinder is connected to multiple plugs arranged in a circumferential array that can be inserted into the slots from bottom to top. A clamp is installed above the mounting platform that can be installed and removed from the plugs by means of threads.

6. The planktonic net with an in-situ separation and sampling device according to claim 5, characterized in that, The surface of the clamp is provided with multiple evenly distributed clearance grooves, and the surface of the mounting platform is provided with multiple evenly distributed clearance grooves that correspond to the clearance grooves above and below.

7. The planktonic net with an in-situ separation and sampling device according to claim 1, characterized in that, The planktonic net includes a net body and a mesh opening installed at the center of the bottom of the net body; the top of the net body is the mesh opening, and an elastic rope that can change the size of the opening is installed at the edge of the mesh opening.

8. The planktonic net equipped with an in-situ separation and sampling device according to claim 7, characterized in that, The top of the net is provided with a main traction rope, which is connected to multiple circumferentially distributed auxiliary traction ropes through a ball knot. All the auxiliary traction ropes pass through the rope loops installed on the outside of the net and are finally led to the in-situ separation sampling device.

9. The planktonic net with an in-situ separation and sampling device according to claim 8, characterized in that, The connector includes a connecting sleeve, the top of which is connected to the inner wall of the mesh nozzle by a thread, and the bottom of which is connected to the inner wall of the separation chamber by a thread.

10. The planktonic net with an in-situ separation and sampling device according to claim 9, characterized in that, The side wall of the connecting sleeve is connected to a number of traction ears equal to the number of auxiliary traction ropes, and the traction ears are provided with traction grooves for suspending the auxiliary traction ropes.

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