A pressurized aeration filter for recirculating aquaculture systems

Abstract

This utility model belongs to the field of aquaculture equipment technology, and relates to a pressurized aeration filter tank for recirculating aquaculture systems (RAS). It includes a pressurized sealed tank body, a Venturi jet injector, a bag filter, a pressure cylinder, and a return water pipeline system. Through integrated design, it achieves aeration, filtration, and biological purification functions. Utilizing the negative pressure aeration of the Venturi jet injector, the self-cleaning of the filter bag's gradient pores, and the secondary mixing of concentrated air in the pressure cylinder, it solves the problems of low integration, easy clogging, high energy consumption, and poor adaptability of traditional RAS systems. This utility model is suitable for high-density recirculating aquaculture and has the advantages of energy saving, easy maintenance, and stable operation.

Description

Technical Field

[0001] This utility model belongs to the field of aquaculture equipment technology, specifically relating to a pressurized oxygenation filter barrel for factory-scale recirculating aquaculture (RAS). Background Technology

[0002] Recirculating aquaculture systems (RAS) are key equipment for the intensive development of aquaculture, but existing technologies have the following drawbacks in the filtration and aeration stages: 1. Low system integration: Physical filtration, biological purification and oxygenation functions are mostly combined with decentralized equipment, resulting in complex pipelines, large footprint and serious energy loss.

[0003] 2. Filter media is prone to clogging: Traditional filter screens or filter bags are easily clogged by suspended solids (such as feces and uneaten feed), requiring frequent cleaning or replacement, resulting in high maintenance costs.

[0004] 3. High energy consumption: The power efficiency of air pumps or blowers for oxygenation is low, and electricity consumption accounts for more than 30% of the operating cost.

[0005] 4. Poor pressure adaptability: Non-pressure-bearing equipment cannot adapt to system pressure fluctuations, has limited installation location, and lacks stability.

[0006] Although some technological attempts have been made to improve the system through integrated design or self-cleaning functions, none of these have fundamentally solved the above problems. Therefore, there is an urgent need for a highly integrated, self-cleaning, efficient, energy-saving, and pressure-resistant all-in-one filtration and oxygenation device. Utility Model Content

[0007] To address the aforementioned problems in existing technologies, this solution provides a pressurized aeration filter barrel for recirculating aquaculture systems.

[0008] The technical solution adopted in this utility model is as follows: A pressurized aeration filter tank for recirculating aquaculture systems includes: The pressure-bearing sealed barrel has an internal partition that divides the barrel cavity into a water guide channel and a filter chamber. The Venturi jet injector is installed inside the water guide channel; its water inlet end is connected to the water inlet on the wall of the pressure-bearing sealed barrel, its air inlet end extends out of the pressure-bearing sealed barrel, and its water outlet end sprays a mixture of air and water into the water guide channel. Multiple bag filters are installed inside a pressure-bearing sealed tank; the upper end of each bag filter is connected to a water guide channel through a filter sealing joint on a partition; the filter bag of each bag filter has a pore gradient that is larger at the top and smaller at the bottom; a coarse filter body is provided in the middle of the filter bag body; The pressure cylinder is located at the center hole of the partition and is connected to the filter chamber. The return water pipe is installed in the filter chamber. Its upper end extends into the pressure cylinder and connects to the return water pipe head, while its lower end connects to the return water outlet on the wall of the pressure-bearing sealed tank via a mixer. The return water pipe, return water pipe head, and mixer together constitute the return water pipeline system.

[0009] As an alternative or supplement to the above structure: the upper end of the pressure cylinder extends from the top of the pressure-bearing sealing barrel and is sealed by a detachable cylinder cover, which facilitates installation and maintenance.

[0010] As an alternative or supplement to the above structure: the mixer includes a mixing tube and a spiral baffle fixed therein for enhancing gas-water mixing.

[0011] As an alternative or supplement to the above structure: the mixer has two units, which are connected in series and parallel, and their lower ends are connected by elbows. The pipe between the elbows is fixed to the bottom of the pressure-bearing sealed barrel by a support plate.

[0012] As an alternative or supplement to the above structure: the coarse filter body is located in the middle of the filter bag body, dividing the filter bag body into two filter bag cavities, one upper and one lower. The coarse filter body divides the filter bag body into two filter bag cavities, and the lower end is provided with a fine filter body to achieve graded filtration.

[0013] As an alternative or supplement to the above structure: the lower end of the filter bag is gathered and provided with a fine filter body.

[0014] As an alternative or supplement to the above structure: the water guide channel is circular, and the two Venturi jets are symmetrically distributed in a figure-eight shape with the water outlet directions obliquely opposite each other, so that the water flow collision enhances oxygenation.

[0015] As an alternative or supplement to the above structure: the lower part of the pressure cylinder is provided with a return water pipe frame, which is cross-shaped / Y-shaped, and the return water pipe is fixed at its center.

[0016] The beneficial effects of this utility model are as follows: 1. Integrated design: Through the synergistic design of Venturi jet oxygenation, bag filtration and pressure cylinder secondary oxygenation, the physical filtration, biological purification and oxygenation functions are highly integrated, reducing system size and energy consumption; 2. Self-cleaning and anti-clogging: The gradient pores of the filter bag and the coarse filter body form a microbial carrier, which degrades organic matter and effectively prevents clogging; when the internal pressure is ≥0.2MPa, the coarse filter body elastically deforms to release pressure, extending the filter bag's lifespan; 3. Energy-saving and efficient: The Venturi jet uses the negative pressure of water flow to draw in air, eliminating the need for an additional air pump; the mixer provides secondary aeration to increase dissolved oxygen to 20–40 L / min, improving power efficiency by more than 30% compared to traditional equipment; 4. Strong pressure adaptability: The sealed tank has a pressure-bearing capacity of up to 0.5MPa and can be installed at any position in the pipeline to adapt to water pressure fluctuations in high-density aquaculture; 5. Low maintenance cost: The bag filters are designed in parallel, so a single failure will not affect the overall operation. They are cleaning-free and have a service life of more than 10 years. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this scheme or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0018] Figure 1 This is a cross-sectional structural diagram of the pressure-bearing oxygen-enriching filter barrel in this scheme; Figure 2 This is a partial structural diagram of the pressure cylinder; Figure 3 This is a schematic diagram of the mixer (used to show the spiral baffle). Figure 4 This is a structural diagram of a bag filter (used to show the gradient pores and the coarse filter body). Figure 5 yes Figure 1 Structural diagram of section AA (used to show the layout of the water guide channel and Venturi jet); Figure 6 This is a diagram showing the operational status of a Venturi jet injector.

[0019] In the diagram: 1-Pressure-bearing sealed tank; 2-Drain valve; 3-Mixer; 31-Spiral baffle; 4-Support plate; 5-Bag filter; 51-Filter bag body; 52-Filter sealing joint; 53-Filter bag cavity; 54-Coarse filter body; 55-Fine filter body; 7-Return water pipe head; 8-Pressure cylinder; 9-Baffle plate; 10-Return water pipe rack; 11-Return water pipe; 12-Venturi jet; 121-Air inlet joint; 122-Welding part; 13-Elbow; 14-Return water outlet; 15-Water inlet. Detailed Implementation

[0020] The technical solutions in this embodiment will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only a part of the embodiments, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments in this solution without creative effort are within the protection scope of this solution.

[0021] Example like Figures 1 to 6As shown in the figure, this embodiment designs a pressure-bearing oxygenation filter barrel for aquaculture recirculating aquaculture, including a pressure-bearing sealed barrel body 1, a drain valve 2, a mixer 3, a support plate 4, a bag filter 5, a return water pipe head 7, a pressure cylinder 8, a partition 9, a return water pipe rack 10, a return water pipe 11, a Venturi jet 12, an elbow 13, a return water outlet 14, and a water inlet 15, etc.

[0022] The pressure-bearing sealed tank 1 is made of PP material and has a cylindrical structure. It has a water inlet 15 and a return outlet 14 at the top, and a drain valve 2 at the bottom. A partition 9 is installed at the top inner part of the pressure-bearing sealed tank 1, dividing the tank cavity into a water guide channel and a filter chamber. The water guide channel is used for water flow mixing and guidance. The filter chamber is used to install a bag filter 5 for filtration. Through the distribution of the water guide channel, the oxygenated water can be evenly guided into the bag filter 5.

[0023] Two DN50 Venturi jets 12 are symmetrically arranged inside the water guide channel, with their outlet directions opposite each other, allowing the water to collide and mix before uniformly entering the bag filter 5. The water inlet of the Venturi jet 12 is connected to the water inlet 15 on the wall of the pressure-bearing sealed tank 1, the air inlet extends outside the pressure-bearing sealed tank 1, and the water outlet sprays a mixed air-water flow into the water guide channel. The water guide channel is annular, and the two Venturi jets 12 are distributed in a figure-eight shape within the channel, with their outlets facing different directions. The water jets from the two Venturi jets 12 collide after being guided by the channel wall. The Venturi jets 12 can be existing DN50 models. The Venturi jets 12 can generate negative pressure, automatically drawing in air and mixing it thoroughly with the water flow to form millimeter-level microbubbles, providing sufficient dissolved oxygen for the cultured organisms and effectively solving the problem that traditional air aeration technology cannot meet the needs of high-density aquaculture. Meanwhile, the figure-eight distribution pattern enables symmetrical distribution and efficient mixing of water flow, significantly improving the air-water mixing efficiency and ensuring the system's oxygenation effect.

[0024] The filter bag 5 has a filter bag body 51 with an upper pore size of 100μm and a lower pore size of 50μm. The middle coarse filter body 54 is made of cotton material, used to cultivate nitrifying bacteria to degrade ammonia nitrogen and nitrite. Multiple bag filters 5 are present, each housed within a pressure-bearing sealed tank 1 and used for filtering circulating water. The upper end of each bag filter 5 is connected to a water guide channel via a filter sealing joint on a partition 9. Water from the water guide channel can enter each bag filter 5 through the filter sealing joint. The bag filters 5 are connected in parallel, so a malfunction in one bag filter 5 will not affect the normal operation of the others. The filter bag body 51 of the bag filter 5 can filter water; the pore size at the upper part of the filter bag body 51 is larger than that at the lower part, and a coarse filter body 54 is provided between the upper and lower parts to facilitate the degradation of organic matter in the water by microorganisms within the coarse filter body 54.

[0025] The coarse filter body 54 is located in the middle of the filter bag body 51, dividing the filter bag body 51 into two filter bag chambers 53, one upper and one lower. The upper filter bag chamber 53 forms a pre-filter zone, used for coarse filtration of particulate matter in the circulating water and forming a biofilm carrier. The lower end of the filter bag body 51 is gathered together and a fine filter body 55 is provided. The lower filter bag chamber 53 is located between the fine filter body 55 and the coarse filter body 54 and forms a post-filter zone, used for fine filtration of particulate matter in the circulating water and for automatic pressure relief. Through the design of the pre-filter and post-filter zones, not only is the dual filtration effect of physical interception and biodegradation achieved, but the automatic pressure relief function of the post-filter zone also effectively prevents filter bag clogging, extends the service life of the filter bag, and greatly reduces cleaning and maintenance costs.

[0026] The pressure cylinder 8 is connected to the filter chamber through the central hole of the partition 9, and the upper end of the pressure cylinder extends out of the pressure-bearing sealed barrel body. The water-insoluble air in the filter chamber rises under the action of buoyancy and then continuously accumulates in the pressure cylinder 8, which increases the air pressure in the pressure cylinder 8, so that the air and water can mix and flow out from the return water pipe head 7, and at the same time realize the secondary oxygenation of the water. The upper end of the pressure cylinder 8 extends from the center of the upper end face of the pressure-bearing sealed barrel body 1 and is detachably connected to the cylinder cover. The edge of the cylinder cover can be fastened with 28 M8×35 stainless steel bolts and a nitrile rubber sealing gasket is set, which effectively solves the problem of easy leakage in traditional systems and improves the safety and reliability of the equipment.

[0027] The collected air and filtered water enter the return water pipe 11 from the return water pipe head 7, and are discharged after secondary oxygenation by two series parallel mixers 3 (with built-in spiral baffles 31). The mixers 3 are fixed by elbows 13 and support plates 4. The return water pipe 11 is set in the filter chamber, with its upper end extending into the pressure cylinder 8 and connected to the return water pipe head 7. The lower part of the pressure cylinder 8 is provided with a cross-shaped, straight, or Y-shaped return water pipe rack 10, and the return water pipe 11 is connected to the center of the return water pipe rack 10. The lower end of the return water pipe 11 is connected to the return water outlet 14 on the wall of the pressure-bearing sealed tank 1 through one or more mixers 3. The mixers 3 include two parallel mixers, and the lower ends of the two mixers 3 are connected by two elbows 13; the pipe between the two elbows 13 is connected to the bottom wall of the pressure-bearing sealed tank 1 through the support plate 4. The mixer 3 includes a mixing pipe and a spiral baffle 31, with the spiral baffle 31 set inside the mixing pipe.

[0028] Workflow: Circulating water enters the Venturi jet injector 12 through inlet 15, draws in air, and is sprayed into the guide channel. After initial oxygenation, it enters the bag filter 5 for filtration. The filtered water mixes with air in the pressure cylinder 8, and after secondary mixing and oxygenation through the return pipe 11 and mixer 3, it flows back to the aquaculture tank from the return outlet 14. Impurities settled at the bottom of the tank are periodically discharged through the drain valve 2.

[0029] This equipment can process flow rates of 25-35T / h and is suitable for high-density aquaculture of freshwater and brackish water fish, shrimp, and other species.

[0030] The above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation; it is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom remain within the scope of this technology.

Claims

1. A pressurized aeration filter barrel for recirculating aquaculture systems, characterized in that: include: The pressure-bearing sealed barrel (1) has a partition (9) inside, which divides the barrel cavity of the pressure-bearing sealed barrel (1) into a water guide channel and a filter chamber; Venturi jet (12) is installed in the water guide channel; its water inlet end is connected to the water inlet (15) on the wall of the pressure-bearing sealed barrel (1), its air inlet end extends out of the pressure-bearing sealed barrel (1), and its water outlet end sprays air-water mixture into the water guide channel; Multiple bag filters (5) are installed inside a pressure-bearing sealed barrel (1); the upper end of the bag filter (5) is connected to the water guide groove through a filter sealing joint on the partition (9); the filter bag body (51) of the bag filter (5) has a pore gradient with larger pores at the top and smaller pores at the bottom; a coarse filter body (54) is provided in the middle of the filter bag body (51). The pressure cylinder (8) is located at the center hole of the partition (9) and is connected to the filter chamber; The return water pipe (11) is installed in the filter chamber. Its upper end extends into the pressure cylinder (8) and is connected to the return water pipe head (7). Its lower end is connected to the return water outlet (14) on the wall of the pressure-bearing sealed barrel (1) through the mixer (3).

2. The pressurized aeration filter tank for recirculating aquaculture as described in claim 1, characterized in that: The upper end of the pressure cylinder (8) extends from the top of the pressure-bearing sealing cylinder body (1) and is sealed by a removable cylinder cover.

3. The pressurized aeration filter barrel for recirculating aquaculture as described in claim 1, characterized in that: The mixer (3) includes a mixing tube and a spiral baffle (31) fixed therein.

4. The pressurized aeration filter tank for recirculating aquaculture as described in claim 3, characterized in that: The mixer (3) has two units, which are connected in series and arranged in parallel. The lower ends of the two units are connected by elbows (13), and the pipe between the elbows (13) is fixed to the bottom of the pressure-bearing sealed barrel (1) by a support plate (4).

5. The pressurized aeration filter barrel for recirculating aquaculture as described in claim 1, characterized in that: The coarse filter body (54) is located in the middle of the filter bag body (51) and divides the filter bag body (51) into two filter bag cavities (53), one above the other.

6. The pressurized aeration filter barrel for recirculating aquaculture as described in claim 5, characterized in that: The lower end of the filter bag (51) is gathered together and equipped with a fine filter body (55).

7. The pressurized aeration filter tank for recirculating aquaculture as described in claim 1, characterized in that: The water guide channel is circular, and the two Venturi jets (12) are symmetrically distributed in a figure-eight shape with their water outlet directions obliquely opposite each other.

8. The pressurized aeration filter tank for recirculating aquaculture as described in claim 1, characterized in that: The pressure cylinder (8) is provided with a return water pipe bracket (10) at the lower part, and the return water pipe (11) is fixed at its center.

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