A multi-stage gradient filtration concentration sampling device and method for ship ballast water

Abstract

The application discloses a kind of ship ballast water multistage gradient filtration concentration sampling device and method, belong to ship ballast water detection technical field, the device includes pipeline connection unit, multistage gradient filtration unit, flow monitoring unit and sample collection unit, multistage gradient filtration unit uses coaxial nested outer cylinder and inner cylinder structure, 50 μm first filter screen assembly is installed between outer cylinder and inner cylinder, 10 μm second filter screen assembly is installed in inner cylinder, and bottom is separately provided with independent enrichment collection cavity, the present application can be completed in single sampling process Synchronous two types of indicator organism grading enrichment concentration, with the advantages of simple operation, high concentration efficiency, sampling data is traceable.

Description

Technical Field

[0001] This invention relates to the field of ship ballast water testing equipment, and more specifically, to a multi-stage gradient filtration concentration sampling device and method for ship ballast water. Background Technology

[0002] According to the International Maritime Organization (IMO) Convention 2004 on the Control and Management of Ship Ballast Water and Sediments, ballast water discharged from ships must meet the D-2 discharge control standard, which stipulates that the number of surviving organisms with a minimum size of 50 μm or greater should be less than 10 per m³. 3 The number of surviving organisms with a minimum size of 10 μm or greater and less than 50 μm should be less than 10 per mL. To verify whether ship ballast water meets discharge standards, on-site sampling and indicative analysis are required when the ship discharges ballast water.

[0003] Currently, ship ballast water sampling equipment typically uses a single-stage filter screen for sampling. Separate sampling operations are required for viable organisms larger than or equal to 50 μm and for viable organisms larger than or equal to 10 μm but smaller than 50 μm. Sampling of viable organisms larger than or equal to 50 μm requires filtering at least 1000 L of ballast water using a 50 μm plankton screen, then collecting the concentrated sample in a polyethylene bottle. Sampling of viable organisms larger than or equal to 10 μm but smaller than 50 μm requires collecting the water sample again after filtration through the plankton screen, accumulating a total of at least 5 L. This step-by-step operation presents the following technical problems: First, the separate sampling of the two types of indicator organisms is cumbersome, time-consuming, and disrupts normal ship operations. Second, water quality conditions may change during the two sampling processes, leading to insufficient representativeness of the test results. Third, sample transfer during multiple transfers can easily cause biological loss and cross-contamination, affecting test accuracy. Fourth, existing equipment lacks intelligent monitoring and automatic adjustment functions for sampling flow rate, relying on manual experience to control the flow rate, making it difficult to ensure consistency of sampling conditions.

[0004] Therefore, it is necessary to develop a ship ballast water sampling device that can simultaneously achieve graded enrichment and concentration of two types of indicator organisms in a single sampling process, in order to improve sampling efficiency, reduce operation steps, and ensure the accuracy and traceability of test results. Summary of the Invention

[0005] In view of the above-mentioned problems in the prior art, the purpose of this invention is to provide a multi-stage gradient filtration concentration sampling device and method for ship ballast water, so as to solve the technical problems of existing ballast water sampling requiring step-by-step operation, low concentration efficiency, and untraceable sampling data.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A multi-stage gradient filtration and concentration sampling device for ship ballast water includes a pipeline connection unit, a multi-stage gradient filtration unit, a flow monitoring unit, and a sample collection unit. The pipeline connection unit includes a sampling probe, a connecting hose, and a quick-connect assembly. One end of the sampling probe is adapted to and fixed to the sampling port of the ship's ballast water discharge pipeline, and the other end of the sampling probe is sealed and connected to the quick-connect assembly via the connecting hose. The outlet end of the quick-connect assembly is fixedly connected to the inlet of the multi-stage gradient filtration unit. The multi-stage gradient filtration unit includes an outer cylinder, an inner cylinder coaxially fitted within the inner cavity of the outer cylinder, a first-stage filter assembly installed between the inner wall of the outer cylinder and the outer wall of the inner cylinder, and a second-stage filter assembly installed on the inner wall of the inner cylinder. The first-stage filter assembly has a pore size of 50 μm, and the second-stage filter assembly has a pore size of 10 μm. The bottom of the outer cylinder has a first concentration and collection chamber for enriching viable organisms with a minimum size greater than or equal to 50 μm, and the bottom of the inner cylinder has a second concentration and collection chamber for enriching viable organisms with a minimum size greater than or equal to 10 μm but less than 50 μm. The top of the inner cylinder has an overflow outlet. The flow monitoring unit includes an electromagnetic flow meter, a first differential pressure sensor, a second differential pressure sensor, and an intelligent controller. The intelligent controller adjusts the opening of the electric regulating valve based on the real-time flow signal to control the sampling flow rate within a range not exceeding 50 L / min. The sample collection unit includes collection bottles and discharge valves respectively sealed and connected to the bottom discharge outlets of the two concentration and collection chambers.

[0007] Compared with the prior art, the present invention has the following advantages: (1) The present invention adopts a coaxial nested double cylinder structure with two-stage filter components with different pore sizes, which realizes the graded enrichment and concentration of two types of indicator organisms with a diameter greater than or equal to 50 μm and a diameter of 10-50 μm in a single sampling process. No step-by-step operation is required, which shortens the sampling time by about 40%-60% and significantly improves the sampling efficiency.

[0008] (2) The two types of biological samples were collected simultaneously in the same sampling process and under the same water quality conditions, which avoided the problem of water quality changes caused by step sampling and improved the representativeness and comparability of the test results.

[0009] (3) Concentrated samples are directly discharged into collection bottles through their respective independent concentration collection chambers, reducing the number of sample transfers and effectively reducing the risk of biological loss and cross-contamination.

[0010] (4) The flow monitoring unit realizes automatic adjustment of sampling flow and full-process data recording through closed-loop control of electromagnetic flow meter and intelligent controller, ensuring the consistency and traceability of sampling conditions. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the longitudinal cross-sectional structure of the multi-level gradient filtering unit of the present invention; Figure 3 This is a top view of the first-stage filter assembly of the present invention. Figure 4 This is a top view of the second-stage filter assembly of the present invention; Figure 5 This is a schematic diagram of the backwashing mechanism of the present invention; Figure 6 This is a schematic diagram of the control principle of the flow monitoring unit of the present invention; Figure 7 This is a schematic diagram of the sample collection unit of the present invention; Figure 8 This is a schematic diagram of the portable support frame of the present invention.

[0012] In the diagram: 1-Pipeline connection unit, 101-Sampling probe, 102-Connecting hose, 103-Quick connector assembly, 104-Anti-siphon valve, 2-Multi-stage gradient filtration unit, 201-Inlet, 202-Outer cylinder, 203-Inner cylinder, 204-First-stage filter assembly, 2041-Annular support frame, 2042-316L stainless steel braided filter screen, 2043-Sealing ring, 205-Second-stage filter assembly, 2051-Circular support frame, 2052-Nylon precision filter screen, 206-First concentration collection chamber, 2061-Conical guide surface, 207-Second concentration collection chamber, 2071-Conical guide surface, 208-Overflow outlet, 209-Drainage pipeline, 210-Sealing end cap, 211-Clamping clamp. 212-Guide cone, 213-Backwashing mechanism, 2131-Compressed gas cylinder, 2132-Pressure reducing valve, 2133-Gas pipe, 2134-First solenoid valve, 2135-Second solenoid valve, 3-Flow monitoring unit, 301-Electromagnetic flow meter, 302-First differential pressure sensor, 303-Second differential pressure sensor, 304-Intelligent controller, 3041-Data storage module, 3042-Display screen, 3043-Wireless communication module, 305-Electric regulating valve, 4-Sample collection unit, 401-First collection bottle, 402-Second collection bottle, 403-First discharge valve, 404-Second discharge valve, 5-Portable support frame, 501-Fastening strap, 502-Universal casters, 503-Folding handle. Detailed Implementation

[0013] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0014] like Figure 1 and Figure 8As shown, the multi-stage gradient filtration and concentration sampling device for ship ballast water provided by the present invention includes a pipeline connection unit 1, a multi-stage gradient filtration unit 2, a flow monitoring unit 3, a sample collection unit 4, and a portable support frame 5. The pipeline connection unit 1 is used to reliably connect the device to the ship's ballast water discharge pipeline. The multi-stage gradient filtration unit 2, as a core functional module, is used for gradient filtration and graded concentration of surviving organisms of different sizes in the ballast water. The flow monitoring unit 3 is used for intelligent monitoring and data recording of the entire sampling process. The sample collection unit 4 is used to receive and store the concentrated biological samples. The portable support frame 5 is used to support and fix the above functional units to achieve overall portability.

[0015] like Figure 1 As shown, the pipeline connection unit 1 includes a sampling probe 101, a connecting hose 102, a quick-connect assembly 103, and an anti-siphon valve 104. The sampling probe 101 is a stainless steel tubular structure, with one end having an external thread or flange structure to adapt to the standard sampling port of the ship's ballast water discharge pipeline. The inner diameter of the sampling probe 101 is 25-40 mm to meet the sampling flow rate requirement of no more than 50 L / min. The other end of the sampling probe 101 is sealed and connected to one end of the connecting hose 102 via a quick-clamp connection. The connecting hose 102 is made of food-grade silicone or PTFE-lined hose, with a length of 2-5 m to accommodate different distances between sampling points and operating positions on different ships. The other end of the connecting hose 102 is sealed and connected to the quick-connect assembly 103 via a quick-clamp connection. The quick-connect assembly 103 uses a stainless steel quick-plug connector to achieve quick and sealed connection and disassembly with the inlet 201 of the multi-stage gradient filter unit 2. The anti-siphon valve 104 is installed on the pipeline section between the quick connector assembly 103 and the inlet 201. It is equipped with a spring-reset one-way valve core. When the liquid pressure in the pipeline is lower than the preset value, it will automatically close to prevent the residual liquid in the pipeline from siphoning back into the ship's ballast water system after sampling, thus avoiding contamination of the test results.

[0016] like Figure 2 As shown, the multi-stage gradient filtration unit 2 is the core functional module of the present invention, including an outer cylinder 202, an inner cylinder 203, a first-stage filter assembly 204, a second-stage filter assembly 205, a first concentration collection chamber 206, a second concentration collection chamber 207, and a backwashing mechanism 213.

[0017] like Figure 2As shown, the outer cylinder 202 is a cylindrical stainless steel cylinder structure, made of 316L stainless steel to meet the corrosion resistance requirements of seawater environments. The inner diameter of the outer cylinder 202 is 150-250mm, the height is 400-600mm, and the wall thickness is 2-3mm. A detachable sealing end cap 210 is provided at the top of the outer cylinder 202. The sealing end cap 210 is fixed to the top flange of the outer cylinder 202 by a clamp 211. The sealing end cap 210 and the outer cylinder 202 are sealed together by a silicone rubber O-ring. A water inlet channel is provided in the center of the sealing end cap 210, and the outer end of the water inlet channel is the water inlet 201, used to connect to the water outlet of the flow monitoring unit 3. A guide cone 212 is fixedly connected to the inner end of the water inlet channel. The guide cone 212 is a conical stainless steel distributor with a cone angle of 60°-90°. It is located in the upper part of the inner cavity of the outer cylinder 202 and the opening faces downward. This allows the incoming ballast water to be evenly diffused to the entire effective filtration area of ​​the first-stage filter assembly 204 through the conical surface of the guide cone 212, avoiding concentrated impact of high-speed water flow on local areas of the filter screen, which could cause biological damage or filter screen deformation.

[0018] like Figure 2 As shown, the inner cylinder 203 is a cylindrical stainless steel cylinder structure, coaxially fitted within the center of the inner cavity of the outer cylinder 202. The inner diameter of the inner cylinder 203 is 60-120mm, and its height matches that of the outer cylinder 202. An annular water passage is formed between the outer wall of the inner cylinder 203 and the inner wall of the outer cylinder 202, and the bottom of this annular water passage is connected to the first concentration and collection chamber 206. The top of the inner cylinder 203 is provided with an overflow outlet 208. The clean water after two stages of filtration flows into the drain pipe 209 through the overflow outlet 208. The drain pipe 209 can be connected to a return water pipe or a discharge port. The top of the inner cylinder 203 is connected to the sealing end cap 210 by a seal, ensuring that the ballast water entering the inner cavity of the outer cylinder 202 must first pass through the first-stage filter assembly 204 before entering the inner cylinder 203, and will not overflow directly from the top into the inner cylinder 203.

[0019] like Figure 2 and Figure 3As shown, the first-stage filter assembly 204 is installed in the annular space between the inner wall of the outer cylinder 202 and the outer wall of the inner cylinder 203, and its installation position is below the guide cone 212. The first-stage filter assembly 204 includes an annular support frame 2041 and a 316L stainless steel woven filter mesh 2042 welded and fixed to the surface of the annular support frame 2041. The annular support frame 2041 is a stainless steel annular frame structure, with its outer edge abutting against the inner wall of the outer cylinder 202 through a silicone rubber sealing ring 2043, and its inner edge abutting against the outer wall of the inner cylinder 203 through a silicone rubber sealing ring 2043, forming a sealed annular filter surface. The diagonal size of the mesh opening of the 316L stainless steel woven filter mesh 2042 is 50±2μm, and its effective filtration area is determined based on the annular area between the outer cylinder 202 and the inner cylinder 203. When ballast water passes through the first-stage filter assembly 204, surviving organisms with a minimum size of 50 μm or greater are trapped on the surface of the filter screen and slid down and settle along the filter screen surface to the first concentration collection chamber 206 at the bottom of the annular channel as the water flows.

[0020] like Figure 2 and Figure 4 As shown, the second-stage filter assembly 205 is installed on the inner wall of the inner cylinder 203, located slightly below the center of the inner cylinder 203. The second-stage filter assembly 205 includes a circular support frame 2051 and a nylon precision filter screen 2052 fixed to the surface of the circular support frame 2051. The circular support frame 2051 is a stainless steel circular frame structure, with its outer edge abutting against the inner wall of the inner cylinder 203 via a sealing ring. The diagonal size of the mesh openings of the nylon precision filter screen 2052 is 10±1μm. The advantage of nylon material is its smooth surface and low bioadhesion, which facilitates the complete detachment of trapped microorganisms during subsequent collection. Water samples filtered by the first-stage filter assembly 204 entering the inner cylinder 203 are filtered by the second-stage filter assembly 205. Viable organisms with a minimum size greater than or equal to 10μm and less than 50μm are trapped and settle into the second concentration and collection chamber 207.

[0021] like Figure 2 As shown, the first concentration and collection chamber 206 is located at the bottom of the outer cylinder 202. Its inner wall is provided with a conical guide surface 2061, with a cone angle of 30°-60°. This allows surviving organisms trapped by the first-stage filter assembly 204 to slide naturally down the conical surface under gravity to the discharge port at the bottom of the collection chamber, improving the biomass recovery rate. The effective volume of the first concentration and collection chamber 206 is 50-200 mL. The second concentration and collection chamber 207 is located at the bottom of the inner cylinder 203. Its structure and the design of the conical guide surface 2071 are similar to the first concentration and collection chamber 206, with an effective volume of 20-100 mL. The conical guide surface design eliminates dead zones within the concentration and collection chamber, preventing biological samples from remaining on the inner wall of the chamber.

[0022] like Figure 5 As shown, the backwashing mechanism 213 includes a compressed gas cylinder 2131, a pressure reducing valve 2132, an air pipe 2133, a first solenoid valve 2134, and a second solenoid valve 2135. The compressed gas cylinder 2131 is a small portable nitrogen cylinder or compressed air cylinder with a volume of 0.5-2L and an inflation pressure of 0.8-1.5MPa. The pressure reducing valve 2132 is installed at the outlet end of the compressed gas cylinder 2131 to stably regulate the output pressure to 0.1-0.3MPa. The air pipe 2133 is led out from the outlet end of the pressure reducing valve 2132 and splits into a first branch and a second branch. The end of the first branch is fixedly connected to the air inlet on the side wall of the first concentration and collection chamber 206, and the end of the second branch is fixedly connected to the air inlet on the side wall of the second concentration and collection chamber 207. The first solenoid valve 2134 and the second solenoid valve 2135 are respectively installed on the first branch and the second branch, and both solenoid valves are electrically connected to the intelligent controller 304. After the sampling is completed and the sample is collected, the first solenoid valve 2134 and the second solenoid valve 2135 are opened in sequence by the intelligent controller 304. Compressed gas is blown from the bottom of the collection chamber upwards to thoroughly wash the biological samples remaining on the filter screen surface and the inner wall of the collection chamber into the collection bottle, ensuring that the biological recovery rate reaches more than 95%.

[0023] like Figure 6 As shown, the flow monitoring unit 3 includes an electromagnetic flowmeter 301, a first differential pressure sensor 302, a second differential pressure sensor 303, an intelligent controller 304, and an electric regulating valve 305. The electromagnetic flowmeter 301 is installed on the upstream side of the inlet 201 pipeline and is used to measure the instantaneous and cumulative flow of ballast water entering the multi-stage gradient filtration unit 2 in real time. Its range is 0-60 L / min, and its accuracy is ±0.5%. The first differential pressure sensor 302 is installed on the upstream and downstream sides of the first-stage filter assembly 204, respectively, and is used to monitor the pressure difference across the first-stage filter assembly 204 in real time. An increase in pressure difference indicates an increase in filter clogging. The second differential pressure sensor 303 is installed on the upstream and downstream sides of the second-stage filter assembly 205, respectively, and is used to monitor the pressure difference across the second-stage filter assembly 205 in real time.

[0024] like Figure 6As shown, the intelligent controller 304 is the core control component of the flow monitoring unit 3 of this invention. It integrates a microprocessor, a data storage module 3041, a display screen 3042, and a wireless communication module 3043. The input terminals of the intelligent controller 304 are electrically connected to the electromagnetic flowmeter 301, the first differential pressure sensor 302, and the second differential pressure sensor 303, respectively, to receive flow and differential pressure signals in real time. The output terminal of the intelligent controller 304 is electrically connected to the electric regulating valve 305 installed at the inlet 201. Through a PID control algorithm, it automatically adjusts the valve opening of the electric regulating valve 305 based on the real-time flow feedback signal from the electromagnetic flowmeter 301, precisely controlling the sampled flow rate within the target value range preset by the operator. When the electromagnetic flowmeter 301 detects an instantaneous flow rate exceeding 50 L / min, the intelligent controller 304 immediately reduces the opening of the electric regulating valve 305 to ensure that the sampled flow rate never exceeds the upper limit requirement of 50 L / min.

[0025] like Figure 6 As shown, the data storage module 3041 uses a large-capacity non-volatile memory to record all operating parameters during the sampling process in real time, including timestamps, cumulative flow, instantaneous flow rate, first-stage filter differential pressure, second-stage filter differential pressure, and electric regulating valve opening. The storage capacity can record no fewer than 100 complete sampling data records, each with a retention period of no less than one year. The display screen 3042 is a color LCD touchscreen that displays the current sampling status parameters in real time, including instantaneous flow, cumulative flow, differential pressure of each filter stage, and the time elapsed during sampling. The wireless communication module 3043 supports Wi-Fi or 4G cellular network communication, enabling real-time or batch transmission of sampling data to the shore-based management terminal or cloud data platform, facilitating remote monitoring and historical retrieval of the detection data.

[0026] like Figure 1 and Figure 6 As shown, the electric regulating valve 305 is installed on the upstream side pipeline of the inlet 201. It adopts an electric ball valve or electric butterfly valve structure. The valve opening can be continuously adjusted within the range of 0%-100%, and the response time is less than 2 seconds, ensuring the timeliness and stability of flow regulation.

[0027] like Figure 7As shown, the sample collection unit 4 includes a first collection bottle 401, a second collection bottle 402, a first discharge valve 403, and a second discharge valve 404. The first collection bottle 401 is a clean, sterile polyethylene bottle with a volume of 250-500 mL, sealed to the outside of the bottom discharge port of the first concentration collection chamber 206 via a threaded connection. The second collection bottle 402 is a clean, sterile polyethylene bottle with a volume of 100-250 mL, sealed to the outside of the bottom discharge port of the second concentration collection chamber 207 via a threaded connection. The first discharge valve 403 is installed between the discharge port of the first concentration collection chamber 206 and the first collection bottle 401, and the second discharge valve 404 is installed between the discharge port of the second concentration collection chamber 207 and the second collection bottle 402. Both discharge valves are manual ball valves or solenoid valves. During sampling, the discharge valves are in the closed state; after sampling is completed, the discharge valves are opened sequentially to discharge the concentrated sample into the corresponding collection bottle.

[0028] like Figure 8 As shown, the portable support frame 5 is a rectangular frame structure welded from stainless steel pipes, with external dimensions of 400mm (length) × 300mm (width) × 700mm (height) and a total weight not exceeding 15kg. The outer cylinder 202 is vertically fixed to the center of the inner side of the portable support frame 5 by fastening straps 501. The fastening straps 501 are stainless steel buckle straps, and their tightness can be adjusted according to the outer diameter of the outer cylinder 202. The intelligent controller 304 is installed on the surface of the upper crossbeam of the portable support frame 5, allowing the operator to conveniently observe the display screen 3042 and operate the touch interface from a standing position. Universal casters 502 are installed at the four corners of the bottom of the portable support frame 5 to move the device on the ship's deck or dock surface. The top of the portable support frame 5 is equipped with a folding handle 503, which can be folded to one side for storage when not in use and flipped upwards for easy lifting by two people during transport.

[0029] The specific operational process for using this invention to sample ballast water from a ship is as follows: like Figure 1 and Figure 8 As shown, during the sampling preparation stage, the operator first pushes the portable support frame 5 to the vicinity of the sampling port of the ship's ballast water discharge pipeline and locks the swivel casters 502 to secure the device. The sampling probe 101 is then fixed to the sampling port using threads or a flange. The sampling probe 101 is connected to the quick-connect assembly 103 using the connecting hose 102, and then the quick-connect assembly 103 is inserted into the inlet 201 of the multi-stage gradient filter unit 2. The sealing of each connection point is checked, confirming that the first discharge valve 403 and the second discharge valve 404 are closed, and that the first collection bottle 401 and the second collection bottle 402 are correctly installed.

[0030] During the pipeline flushing phase, open the valve of the ship's ballast water discharge pipeline to fill the entire sampling pipeline with ballast water and run it continuously for 5 minutes to flush out any residues and air bubbles that may be present in the pipeline. The water discharged during the flushing phase is discharged through overflow outlet 208 and drain pipeline 209. After flushing is completed, close the discharge pipeline valve.

[0031] like Figure 1 , Figure 2 and Figure 6 As shown, during the formal sampling phase, the intelligent controller 304 is activated, and the target sampling flow rate and target sampling total amount are set on the touch screen. The discharge pipeline valve is reopened, and the intelligent controller 304 automatically adjusts the flow rate to the target value via the electric regulating valve 305. Ballast water enters the inlet 201 from the sampling probe 101 through the connecting hose 102, quick connector assembly 103, anti-siphon valve 104, electromagnetic flowmeter 301, and electric regulating valve 305, and is evenly distributed to the upper surface of the first-stage filter assembly 204 by the guide cone 212. Plankton and particulate matter with a minimum size of 50μm or greater are intercepted by the 316L stainless steel woven filter screen 2042 of the first-stage filter assembly 204, and slide down along the conical guide surface 2061 of the annular channel under the action of water flow and gravity to be enriched in the first concentration collection chamber 206.

[0032] like Figure 2 As shown, the water sample filtered by the first-stage filter assembly 204 enters the inner cavity of the inner cylinder 203 through the bottom opening of the annular channel, and then flows upward through the second-stage filter assembly 205. Plankton with a minimum size of 10 μm or greater and less than 50 μm are trapped by the nylon precision filter 2052 of the second-stage filter assembly 205 and settle along the inner wall of the inner cylinder 203 under gravity, accumulating in the second concentration and collection chamber 207. The filtered water flows through the overflow outlet 208 at the top of the inner cylinder 203 and is discharged into the drain pipe 209.

[0033] like Figure 6 As shown, during the sampling and monitoring phase, the intelligent controller 304 continuously performs the following monitoring tasks throughout the sampling process: real-time acquisition of instantaneous and cumulative flow data from the electromagnetic flowmeter 301; automatic fine-tuning of the opening of the electric regulating valve 305 when the instantaneous flow deviates from the target value; real-time acquisition of differential pressure data from the first differential pressure sensor 302 and the second differential pressure sensor 303; when the differential pressure of any stage filter exceeds the preset threshold, the intelligent controller 304 automatically reduces the opening of the electric regulating valve 305 to reduce the flow rate, preventing excessive water pressure from damaging the trapped organisms or breaking the filter; and recording all operating parameters in a time sequence to the data storage module 3041.

[0034] like Figure 7As shown, during the sample collection stage, when the cumulative flow of the electromagnetic flowmeter 301 reaches the preset target sampling amount, the intelligent controller 304 issues an audible and visual alert signal. The operator closes the discharge pipeline valve, and the intelligent controller 304 automatically closes the electric regulating valve 305 to stop sampling. After the residual water in the pipeline is drained, the first discharge valve 403 and the second discharge valve 404 are opened in sequence to discharge the concentrated samples in the first concentration collection chamber 206 and the second concentration collection chamber 207 into the first collection bottle 401 and the second collection bottle 402, respectively.

[0035] like Figure 5 As shown, during the backwashing collection stage, to ensure the complete recovery of residual biological samples on the inner wall of the concentration collection chamber and the surface of the filter screen, after discharging the concentrated sample, the operator sequentially opens the first solenoid valve 2134 and the second solenoid valve 2135 of the backwashing mechanism 213 via the intelligent controller 304. Compressed gas enters from the air inlet on the side wall of the collection chamber, blowing from bottom to top across the inner wall of the collection chamber and the lower surface of the filter screen, rinsing the attached biological samples into the collection bottle. The backwashing time is 10-30 seconds each time. After backwashing is complete, the solenoid valves are closed, the collection bottle is unscrewed and sealed, and the sample identification information is marked.

[0036] During the data export phase, operators can view the complete data record of this sampling through the touch screen interface of the intelligent controller 304, including the sampling start time, end time, total sample volume, average flow rate, and pressure difference curves of each filter stage. Data can be transmitted to the shore-based management terminal via the wireless communication module 3043, or exported via the USB interface.

[0037] In a preferred embodiment of the present invention, the first-stage filter assembly 204 can be designed as a replaceable structure, that is, the annular support frame 2041 can be quickly disassembled and assembled with the outer cylinder 202 and the inner cylinder 203 through the cooperation of sealing rings and slots. When the 316L stainless steel woven filter screen 2042 becomes worn or clogged due to long-term use and cannot be repaired, a new first-stage filter assembly 204 can be quickly replaced. Similarly, the second-stage filter assembly 205 can also be designed as a replaceable structure.

[0038] In another preferred embodiment of the invention, the end of the drainage pipe 209 can be connected to the ship's ballast water return pipe to return the clean water after two-stage filtration to the ballast tank, thus avoiding any impact on the total amount of ballast water during sampling. A small return water pump can be installed on the drainage pipe 209 to provide auxiliary power when the pressure of the ship's ballast water discharge pipe is insufficient to drive the water sample through the two-stage filter screen.

[0039] This invention achieves simultaneous graded enrichment and concentration of two indicator organisms in ship ballast water through the coordinated operation of a pipeline connection unit, a multi-stage gradient filtration unit, a flow monitoring unit, and a sample collection unit. Its core technical mechanism lies in: a coaxial nested double-cylinder structure providing independent filtration spaces and concentration collection chambers for two stages of filter assemblies with different pore sizes, allowing ballast water to sequentially complete two-stage gradient filtration at 50μm and 10μm during a single flow; the synergistic effect of the conical guide surface and gravity settling ensures efficient convergence of trapped organisms to the bottom of the collection chamber; a closed-loop control circuit of electromagnetic flowmeter-intelligent controller-electric regulating valve ensures accurate and stable sampling flow; and a compressed gas backwashing mechanism completely recovers residual organisms from the filter screen and chamber walls to the collection bottle through bottom-up gas purging. These technical features form a complete technical chain: uniform water intake → gradient interception → gravity concentration → closed-loop monitoring → pneumatic recovery, with overall performance far superior to the effect of simply superimposing these features.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A multi-stage gradient filtration, concentration, and sampling device for ship ballast water, characterized in that, include: Pipeline connection unit (1), the inlet end of the pipeline connection unit (1) is adapted to be fixed to the sampling port of the ship ballast water discharge pipeline, and the outlet end of the pipeline connection unit (1) is sealed and connected to the inlet (201) of the multi-stage gradient filtration unit (2). A multi-stage gradient filtration unit (2) includes an outer cylinder (202), an inner cylinder (203) coaxially sleeved within the inner cavity of the outer cylinder (202), a first-stage filter assembly (204) installed between the inner wall of the outer cylinder (202) and the outer wall of the inner cylinder (203), and a second-stage filter assembly (205) installed on the inner wall of the inner cylinder (203). The filter aperture of the first-stage filter assembly (204) is larger than that of the second-stage filter assembly (205). The bottom of the outer cylinder (202) is provided with a first concentration collection chamber (206), the bottom of the inner cylinder (203) is provided with a second concentration collection chamber (207), and the top of the inner cylinder (203) is provided with an overflow outlet (208). The flow monitoring unit (3) includes an electromagnetic flow meter (301) installed on the upstream side of the inlet (201) and an intelligent controller (304) electrically connected to the electromagnetic flow meter (301). The output end of the intelligent controller (304) is electrically connected to an electric regulating valve (305) installed at the inlet (201). The intelligent controller (304) regulates the opening degree of the electric regulating valve (305) according to the real-time flow signal of the electromagnetic flow meter (301). The sample collection unit (4) includes a first collection bottle (401) which is sealed and connected to the bottom outlet of the first concentration collection chamber (206) and a second collection bottle (402) which is sealed and connected to the bottom outlet of the second concentration collection chamber (207).

2. The multi-stage gradient filtration, concentration, and sampling device for ship ballast water according to claim 1, characterized in that, The top of the outer cylinder (202) is provided with a detachable sealing end cap (210). The sealing end cap (210) is fixed to the top flange of the outer cylinder (202) by a clamp (211). The center of the sealing end cap (210) is provided with a water inlet channel coaxial with the water inlet (201). The outlet end of the water inlet channel is fixedly connected to a guide cone (212). The guide cone (212) is located in the upper part of the inner cavity of the outer cylinder (202) and faces the first stage filter assembly (204). The guide cone (212) is used to evenly distribute the incoming ballast water to the surface of the first stage filter assembly (204). The overflow outlet (208) is connected to the return water pipeline through the drainage pipeline (209).

3. The multi-stage gradient filtration, concentration, and sampling device for ship ballast water according to claim 1, characterized in that, The first-stage filter assembly (204) includes an annular support frame (2041) and a 316L stainless steel woven filter mesh (2042) welded and fixed to the surface of the annular support frame (2041). The outer edge of the annular support frame (2041) abuts against the inner wall of the outer cylinder (202) through a sealing ring (2043), and the inner edge of the annular support frame (2041) abuts against the outer wall of the inner cylinder (203) through a sealing ring (2043). The diagonal size of the mesh of the 316L stainless steel woven filter mesh (2042) is 50±2μm.

4. The multi-stage gradient filtration, concentration, and sampling device for ship ballast water according to claim 1, characterized in that, The second-stage filter assembly (205) includes a circular support frame (2051) and a nylon precision filter (2052) fixed to the surface of the circular support frame (2051). The outer edge of the circular support frame (2051) abuts against the inner wall of the inner cylinder (203) through a sealing ring. The diagonal size of the mesh of the nylon precision filter (2052) is 10±1μm.

5. The multi-stage gradient filtration, concentration, and sampling device for ship ballast water according to claim 1, characterized in that, The multi-stage gradient filtration unit (2) further includes a backwashing mechanism (213), which includes a compressed gas cylinder (2131), a pressure reducing valve (2132) installed at the outlet end of the compressed gas cylinder (2131), and a gas pipe (2133) connected to the outlet end of the pressure reducing valve (2132). The gas pipe (2133) is divided into a first branch and a second branch. The end of the first branch is fixedly connected to the side wall air inlet of the first concentration collection chamber (206), and the end of the second branch is fixedly connected to the side wall air inlet of the second concentration collection chamber (207). A first solenoid valve (2134) and a second solenoid valve (2135) are respectively installed on the first branch and the second branch. The first solenoid valve (2134) and the second solenoid valve (2135) are both electrically connected to the intelligent controller (304).

6. The multi-stage gradient filtration, concentration, and sampling device for ship ballast water according to claim 1, characterized in that, The flow monitoring unit (3) further includes a first differential pressure sensor (302) installed on both sides of the first-stage filter assembly (204) and a second differential pressure sensor (303) installed on both sides of the second-stage filter assembly (205). The first differential pressure sensor (302) and the second differential pressure sensor (303) are electrically connected to the intelligent controller (304). The intelligent controller (304) controls the sampling flow rate within a range not exceeding 50 L / min. The intelligent controller (304) is equipped with a data storage module (3041) and a display screen (3042). The data storage module (3041) is used to record the cumulative flow rate, instantaneous flow rate and differential pressure data of each stage of the filter during the sampling process in real time. The display screen (3042) is used to display the sampling status parameters in real time. The intelligent controller (304) is also equipped with a wireless communication module (3043). The wireless communication module (3043) is used to remotely transmit the sampling data to the shore-based management terminal.

7. The multi-stage gradient filtration, concentration, and sampling device for ship ballast water according to claim 1, characterized in that, A first discharge valve (403) is installed at the outlet of the first concentration collection chamber (206), and a second discharge valve (404) is installed at the outlet of the second concentration collection chamber (207). The inner wall of the first concentration collection chamber (206) is provided with a conical guide surface (2061), the cone angle of the conical guide surface (2061) is 30°-60°, and the inner wall of the second concentration collection chamber (207) is provided with a conical guide surface (2071), the cone angle of the conical guide surface (2071) is 30°-60°. The conical guide surface (2061) and the conical guide surface (2071) are used to guide the trapped surviving organisms to the bottom outlet of their respective collection chambers.

8. The multi-stage gradient filtration, concentration, and sampling device for ship ballast water according to claim 1, characterized in that, The pipeline connection unit (1) includes a sampling probe (101), a connecting hose (102), and a quick connector assembly (103). One end of the sampling probe (101) is adapted to be fixed to the sampling port of the ship's ballast water discharge pipeline. The other end of the sampling probe (101) is sealed and connected to the quick connector assembly (103) through the connecting hose (102). The outlet end of the quick connector assembly (103) is fixedly connected to the inlet (201). An anti-siphon valve (104) is installed between the quick connector assembly (103) and the inlet (201). The anti-siphon valve (104) is used to prevent residual liquid in the pipeline from siphoning back to the ship's ballast water system after sampling.

9. The multi-stage gradient filtration, concentration, and sampling device for ship ballast water according to claim 1, characterized in that, It also includes a portable support frame (5), which is a rectangular frame structure welded from stainless steel pipes. The outer cylinder (202) is vertically fixed to the inner side of the portable support frame (5) by fastening straps (501). The intelligent controller (304) is installed on the surface of the upper crossbeam of the portable support frame (5). The bottom of the portable support frame (5) is equipped with universal casters (502), and the top of the portable support frame (5) is provided with a folding handle (503).

10. A method for sampling ship ballast water using the multi-stage gradient filtration and concentration sampling device according to any one of claims 1 to 9, characterized in that, Includes the following steps: Step S1: Fix the sampling probe (101) to the sampling port of the ship's ballast water discharge pipeline, connect the pipeline connection unit (1) to the multi-stage gradient filter unit (2) through the connecting hose (102) and the quick connector assembly (103), and open the ballast water discharge pipeline to fill the pipeline with ballast water and run for 5 minutes to flush the sampling pipeline. Step S2: Start the intelligent controller (304) and adjust the inlet flow rate to 20-50L / min through the electric regulating valve (305). The ballast water enters the inner cavity of the outer cylinder (202) through the inlet (201) and the guide cone (212) in sequence. First, it passes through the first-stage filter assembly (204) for first-stage filtration. Surviving organisms with a minimum size of 50μm or greater are intercepted by the first-stage filter assembly (204) and settle into the first concentration collection chamber (206). Step S3: The water sample filtered by the first-stage filter assembly (204) enters the inner cylinder (203) and undergoes a second-stage filtration through the second-stage filter assembly (205). Surviving organisms with a minimum size greater than or equal to 10μm and less than 50μm are intercepted by the second-stage filter assembly (205) and settle into the second concentration collection chamber (207). The filtered water is discharged through the overflow outlet (208). Step S4: During the sampling process, the intelligent controller (304) collects the flow data of the electromagnetic flowmeter (301) and the differential pressure data of the first differential pressure sensor (302) and the second differential pressure sensor (303) in real time. When the differential pressure of any filter exceeds the preset threshold, the intelligent controller (304) automatically reduces the opening of the electric regulating valve (305) to reduce the flow rate. Step S5: When the cumulative sampling amount of the electromagnetic flowmeter (301) reaches the preset value, the electric regulating valve (305) is closed to stop sampling, and the first discharge valve (403) and the second discharge valve (404) are opened in sequence to discharge the concentrated samples in the first concentration collection chamber (206) and the second concentration collection chamber (207) into the first collection bottle (401) and the second collection bottle (402) respectively.

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