Modularized air-water backwashing type multi-layer filter material cotton-replacement-free filtering equipment and cotton-replacement-free filtering method for aquarium

Abstract

According to the modularized air-water backwashing type multi-layer filter material cotton-replacement-free filtering equipment and the cotton-replacement-free filtering method for the aquarium, efficient backwashing is conducted on the multi-layer particle filter materials through the air-water backwashing system, and the maintenance-free and cotton-replacement-free effects are achieved; a water body is purified by means of the physical interception effect of a filter cavity provided with a plurality of layers of particle filter materials and the nitrification effect of a rear nitrification clear water cavity provided with a microbial carrier filter material, the design thought that purification reaches the standard through multiple times of circulation and accumulation is adopted, and the water body circulation frequency, the water body temperature and the water body dissolved oxygen amount are innovatively and actively optimized to a target interval; the target intervals of the parameters are combined into the volume design of the microbial carrier filter material, so that the purification effect is guaranteed without depending on the large volume of the microbial carrier filter material, and the volume of the microbial carrier filter material and the volume of the whole filter equipment are reduced; the core contradiction of efficient purification, maintenance-free and small size of household and small commercial aquariums is solved.

Description

Technical Field

[0001] This application relates to the field of aquarium technology, specifically to a modular air-water backwashing multi-layer filter media filter device that eliminates the need for cotton replacement, and a cotton replacement-free filtration method for aquariums. Background Technology

[0002] Currently, filtration technology for household and small commercial aquariums has long been limited by the following two traditional design models, neither of which can solve the core contradiction of "high-efficiency purification, maintenance-free operation, and small size": Industrial / municipal filtration models (such as CN106310776A): Their core design principle is "one-time purification to meet standards." To achieve this goal, this model employs extremely thick filter media layers (>1m), extremely high backwashing intensity (>12 L / (m²·s)), and a massive equipment volume. This model completely ignores the fundamental characteristics of closed-loop water circulation and precise environmental control in domestic aquariums. Its design parameters are irreconcilably contradictory to those of domestic applications in terms of volume, energy consumption, and eco-friendliness. Those skilled in the art have no incentive to directly transplant or simply scale it down for domestic use.

[0003] Traditional household filtration systems (such as CN109220961B and CN112021250A) are designed based on the principle of "passive filtration under given environmental constraints." While household aquariums typically operate within certain circulation frequencies, temperature ranges, and dissolved oxygen levels, current technologies treat these parameters as independent background conditions unrelated to the filtration design. This results in: frequent maintenance due to the use of consumables like filter media; arbitrary media combinations lacking quantitative design; reliance on large-volume filter media to compensate for efficiency losses in nitrification; and the absence of backwashing functionality or its conflict with ecological stability. This model fails to consider circulation frequency, dissolved oxygen, and water temperature as actively optimized and synergistic design parameters, leading to redundant product size and cumbersome maintenance. Summary of the Invention

[0004] The purpose of this application is to resolve the core contradiction of "highly efficient purification, maintenance-free operation, and small size" in household and small commercial aquariums. To this end, this application provides the following solution: A modular air-water backwashing type multi-layer filter media filter that requires no cotton replacement, wherein the filter is an independent device with a standardized interface, which can be detachably connected to an aquarium through the standardized interface, and the filter includes: The filtration module, whose inlet and outlet can be connected to the main tank of the aquarium through the standardized interface, includes a filter pump and a buffer chamber, a filter chamber, and a post-nitrification clear water chamber arranged sequentially along the water flow direction. The filter chamber is provided with multiple layers of granular filter media, which include at least two layers of granular filter media with different wet true densities. The wet true density of adjacent filter media increases from top to bottom, and the wet true density difference is ≥1.0g / cm³, so that the layers can be automatically separated and returned to their original positions after backwashing due to the density difference. The post-nitrification clear water chamber is provided with microbial carrier filter media. The backwash system, whose inlet can be connected to the main tank of the aquarium through the standardized interface, includes a backwash fan, a backwash pump, and an air-water distributor located inside the filter chamber and below the bottom layer of filter media. The controller is configured to: control the water temperature, dissolved oxygen content, and water circulation frequency within a target range; calculate the minimum volume of the microbial carrier filter media based on the target range; control the filling amount of the microbial carrier filter media in the post-nitrification chamber or issue a microbial carrier filter media filling prompt signal based on the minimum volume; and execute a filtration process based on the water circulation frequency and an air-water backwash process based on a preset backwash cycle.

[0005] A filter method for aquariums that eliminates the need for filter media replacement, based on the aforementioned filter equipment, includes the following steps: 1) Equipment configuration: The filtration equipment is detachably connected to the aquarium via a standardized interface, ensuring that the inlet and outlet of the filtration module and the inlet of the backwash system are connected to the main tank of the aquarium. Based on the target range of water temperature, dissolved oxygen content and water circulation frequency, the minimum volume of the microbial carrier filter media is calculated using a preset model to ensure that the volume of the microbial carrier filter media in the post-nitrification clear water chamber is not less than the minimum volume. 2) Control the water temperature, dissolved oxygen content, and water circulation frequency within the target range; 3) Execute the filtration process based on the water circulation frequency: Start the filter pump to make the water in the main tank of the aquarium circulate in full based on the water circulation frequency. During circulation, the water flows through the buffer chamber, the multi-layer granular filter media in the filter chamber, and the microbial carrier filter media in the post-nitrification clear water chamber before returning to the main tank of the aquarium. 4) Perform air-water backwashing process based on preset backwashing cycle: First, start the backwashing fan for air washing, then start the backwashing pump for combined air-water washing. During combined air-water washing, the water inside the main tank of the aquarium flows from bottom to top through multiple layers of granular filter media in the filter chamber and is discharged through the backwashing wastewater overflow port.

[0006] In one specific implementation, the controller determines the minimum volume VR of the microbial carrier filter media using the following model: VR = M / (LB · KT · KO · FC); Wherein, M is the preset daily ammonia nitrogen load, LB is the baseline load rate, KT is the temperature synergy factor, KO is the dissolved oxygen synergy factor, and FC is the circulation synergy factor. The temperature synergy factor KT, the dissolved oxygen synergy factor KO, and the circulation synergy factor FC are taken from the target range based on the water temperature, dissolved oxygen content, and water circulation frequency.

[0007] In this embodiment, the water circulation frequency is controlled at 4-8 times / h; the water temperature is controlled at a constant temperature, with a constant temperature range of 25℃-28℃; the dissolved oxygen content is controlled at 4mg / L-6mg / L; the temperature synergy factor KT is 1.4-1.8, the dissolved oxygen synergy factor KO is 1.2-1.5, and the circulation synergy factor FC is 1.5-2.5.

[0008] In this embodiment, the preset backwash cycle includes a high-load corresponding cycle and a normal-load corresponding cycle. The high-load corresponding cycle is 3-5 days, and the normal-load corresponding cycle is 10-15 days. The air-water backwash process includes a two-stage sequence: preferably, first, air washing is performed at an intensity of 6.0-8.0 L / (m²·s) for 2.5-3.0 minutes, followed by combined air-water washing at an intensity of 2.0-2.4 L / (m²·s) and an air-water ratio of 3.0:1-4.0:1 for 1.0-1.2 minutes. After backwashing, the filter media is allowed to stand for 2-3 minutes to allow the filter media to separate into layers.

[0009] In this embodiment, the water consumption for a single backwash accounts for 10%-15% of the total volume of the main tank of the aquarium, and the cumulative water consumption for weekly backwash accounts for 20%-30% of the total volume of the main tank of the aquarium.

[0010] This application breaks through the limitations of traditional design models, innovatively proposing a modular air-water backwashing multi-layer filter media filter device that eliminates the need for cotton replacement in household or small commercial aquariums. Relying on the air-water backwashing system to efficiently backwash the multi-layer granular filter media, it achieves maintenance-free and cotton-replacement-free operation, fundamentally freeing users from maintenance labor and avoiding the risk of water quality deterioration during travel. It purifies the water through the physical interception effect of the filter chamber with multi-layer granular filter media and the nitrification effect of the post-nitrification clearing chamber with microbial carrier filter media. It also breaks through the limitations of traditional single-stage purification designs, adopting a multi-cycle cumulative purification design approach. Furthermore, it innovatively optimizes "water circulation frequency," "water temperature," and "dissolved oxygen content" to target ranges and incorporates these target ranges into the volume design of the microbial carrier filter media. This eliminates the reliance on large-volume microbial carrier filter media to ensure purification effectiveness, resulting in a reduction (over 30%) in the volume of the microbial carrier filter media and the overall filtration device. The resulting aquariums suitable for household and small commercial aquariums are less than 0.1m in size. 3 The aquarium has a large enough capacity and the purification effect fully meets the requirements. It solves the core contradiction of "high-efficiency purification, maintenance-free, and small size" in household and small commercial aquariums. It realizes water change by backwashing, eliminating the need for a separate water change step, making the operation simpler and the control logic simpler. Attached Figure Description

[0011] Figure 1 This is a perspective schematic diagram of one embodiment of the modular air-water backwashing multi-layer filter media cotton-replacement filtration device provided in this application. Figure 2 A schematic diagram of the water flow path during filtration by a filtration device; Figure 3 for Figure 1 A partial three-dimensional schematic diagram; Figure 4 for Figure 1 A partial three-dimensional schematic diagram; Figure 5 This is a schematic diagram of the water flow path during backwashing of the filter equipment. Figure 6 This is a 3D diagram showing the filtration equipment connected to the aquarium. Figure 7 This is a schematic diagram of the operation process of the filtration equipment.

[0012] The annotations in the attached figures are explained as follows: 1. Filtration equipment; 11 Filter module, 111 Buffer chamber, 112 Filter chamber, 113 Post-nitrification water chamber, 114 Upper filter media, 115 Lower filter media, 116 Filter pump, 117 Perforated diverter plate, 118 Perforated support plate, 119 Protective net, 1110 Backwash overflow port, 1111 Inlet pipe, 1112 Return pipe, 1113 Inlet valve, 1114 Electric shut-off valve, 1115 Equipment compartment, 1116 Guide plate, 1117 Thermostatic device; 12 Backwash system, 121 Backwash fan, 122 Backwash pump, 123 Air-water distributor, 123a Water distribution pipe, 123b Air distribution pipe, 124 Wastewater collection tank, 125 Drain valve, 126 Backwash pipe. 2 main cylinders, 3 accommodating chambers. Detailed Implementation

[0013] To enable those skilled in the art to better understand the technical solution of this application, the following description is provided in conjunction with the appendix. Figure 1-7 The present application will be further described in detail below with reference to specific embodiments. The following embodiments can be freely combined without conflict.

[0014] This application provides a modular air-water backwashing type multi-layer filter media filter device that eliminates the need for cotton replacement. For example... Figure 1 As shown, this filtration device is a standalone unit with a standardized interface, allowing it to connect to an aquarium via this interface. The standardized interface refers to the use of universally accepted dimensions in the art for its inner diameter, thread specifications, or snap-fit ​​structure (such as quick connectors with an inner diameter of 20-32mm). This allows the filtration device to achieve a plug-and-play, detachable connection with aquarium main tanks of different brands and sizes through simple plug-and-play operations, without requiring any modification to the main tank, significantly improving the product's versatility and market adaptability. For example, Figure 1 In this design, a standardized interface is provided at the upper end of the inlet pipe 1111, the upper end of the return pipe 1112, and the upper end of the backwash pipe 126. When these three standardized interfaces are connected to the aquarium, the inlet pipe 1111, the return pipe 1112, and the backwash pipe 126 are connected to the interior of the main tank 2 of the aquarium. This design allows the filtration equipment to be used with different main tanks through standardized interfaces, eliminating reliance on a specific main tank structure. It can be sold as part of a main tank assembly or separately to meet the modification needs of existing main tanks.

[0015] The filtration equipment includes a filtration module 11, a backwashing system 12, and a controller (not shown in the figure).

[0016] The filter module's inlet and outlet can be connected to the main tank of the aquarium via standardized interfaces. For example... Figure 1In the process, the standardized interface at the upper end of the inlet pipe 1111 serves as the water inlet of the filter module, and the standardized interface at the upper end of the return pipe 1112 serves as the water outlet of the filter module.

[0017] The filtration module includes a filtration pump 116 and a buffer chamber 111, a filtration chamber 112, and a post-nitrification water purification chamber 113 arranged sequentially along the water flow direction.

[0018] The filter chamber 112 is equipped with multiple layers of granular filter media. In this embodiment, a double-layer granular filter media is used, comprising a lightweight upper layer 114 and a heavyweight lower layer 115. The upper layer is a porous granular filter media, primarily for physical interception and secondarily for nitrification; the lower layer is a heavyweight granular filter media with a wet true density greater than 2.0 g / cm³, focusing on the physical interception of large particles. The wet true density difference between adjacent layers is ≥1.0 g / cm³, allowing for automatic stratification and repositioning after backwashing based on the density difference. For example, the upper layer could be volcanic rock, 120 mm thick, with a particle size of 5-15 mm and a wet true density of 1.2 g / cm³, while the lower layer could be quartz sand, 80 mm thick, with a particle size of 1-1.5 mm and a wet true density of 2.6 g / cm³, resulting in a density difference of 1.4 g / cm³, enabling automatic stratification and repositioning based on the density difference. In the preferred embodiment, the thickness ratio of the upper filter media to the lower filter media is approximately 3:2. Process calculations have verified that this ratio can control the hydraulic loss to below 0.0625m at a filtration rate of 8.33m / h, and ensure that the contaminant saturation rate is below 10% during a 3-day backwash cycle. The stratification is completed within 2-3 minutes after backwashing. It should be noted that this application is not limited to two layers of filter media; three or more layers can be used as needed, as long as the density difference between adjacent layers is ≥1.0g / cm³.

[0019] The post-nitrification water purification chamber 113 is equipped with porous granular microbial carrier filter media (not shown in the figure), such as one or more of ceramsite, quartz balls, and Kaldnes K1 packing. In this embodiment, the post-nitrification water purification chamber has dimensions of 300mm × 200mm × 450mm, and is filled with 18.5L of microbial carrier filter media, with a filter media filling rate of approximately 68.5% and a filter media porosity of approximately 40%, corresponding to an effective reaction water volume of approximately 7.4L. As an exemplary solution, ceramsite and quartz balls are mixed in a 1:1 volume ratio to balance specific surface area and water flow distribution uniformity.

[0020] The backwash system 12 includes a backwash fan 121, a backwash pump 122, and an air-water distributor 123 located inside the filter chamber 112 and below the bottom layer of filter media. The inlet of the backwash system 12 can be connected to the main tank of the aquarium via a standardized interface, for example... Figure 1 In the middle, the standardized interface at the upper end of the backwash pipe 126 serves as the water inlet of the backwash system 12.

[0021] The controller is configured to maintain water temperature, dissolved oxygen levels, and water circulation frequency within target ranges, and to execute the filtration process based on the water circulation frequency. This is achieved through communication connections between the controller and an additional thermostat 1117 located within the buffer chamber, the aquarium's aeration system (if applicable), and the filter pump. The water temperature can be controlled at a constant temperature between 25℃ and 28℃, with a temperature control accuracy of ±0.5℃. Below 25℃, nitrifying bacteria activity significantly decreases, making effective reduction of filter media volume impossible; above 28℃, harmful bacteria easily proliferate, affecting the aquarium's ecological stability. Therefore, this range is the optimal range for balancing nitrification activity and ecological stability. The dissolved oxygen level in the water can be controlled within the range of 4 mg / L to 6 mg / L. Below 4 mg / L, oxygen limitation occurs in the nitrification reaction, reducing the nitrification rate and failing to support the synergistic performance improvement. Above 6 mg / L, aeration energy consumption increases significantly and exceeds the optimal dissolved oxygen requirement for nitrifying bacteria metabolism, offering no additional technical benefit. Therefore, this range is the optimal range for balancing efficiency and energy consumption. The water circulation frequency can be controlled within the range of 4 to 8 times / hour, meaning the water in the main tank is circulated 4 to 8 times per hour. A circulation frequency less than 4 times / hour results in insufficient contact between pollutants and the filter media, failing to achieve the target purification efficiency. A frequency greater than 8 times / hour leads to a significant increase in ecological disturbance, and the excessively fast filtration speed results in hydraulic losses >0.5m, making it unsuitable for the head of domestic pumps. Therefore, this range is the optimal range for achieving compactness and ecological stability.

[0022] The controller is also configured to execute an air-water backwash process based on a preset backwash cycle. This is achieved by enabling the controller to communicate with the backwash pump and backwash fan. The preset backwash cycle can include a high-load corresponding cycle and a normal-load corresponding cycle. The high-load corresponding cycle can be 3-5 days, meaning a backwash is performed every 3-5 days under high load. The normal-load corresponding cycle can be 10-15 days, meaning a backwash is performed every 10-15 days under normal load.

[0023] The controller is also configured to: determine the minimum volume of the microbial carrier filter media by combining the target range of water temperature, dissolved oxygen content and water circulation frequency, and control the filling amount of the microbial carrier filter media in the post-nitrification water purification chamber according to the calculated minimum volume, or issue a microbial carrier filter media filling prompt signal.

[0024] For example, the minimum volume VR of microbial carrier filter media can be determined using the following model: VR = M / (LB · KT · KO · FC).

[0025] in: M is the preset daily ammonia nitrogen load, which is the total mass of ammonia nitrogen that the system needs to process each day (g / day). It is calculated based on the conventional stocking density of home aquariums (1-2 kg / m³) and is suitable for both home and commercial aquarium scenarios. For example, when the load is medium in a 200L main tank and the conventional home stocking density is 1 kg / m³, M can be set to 0.4 g / day.

[0026] LB is the baseline loading rate, which is the volumetric loading rate of the microbial carrier filter media under baseline conditions (20℃, normal oxygen, low-frequency circulation). For example, it can be taken as 0.05 g / (L). It is suitable for commonly used porous nitrification filter media such as ceramsite and quartz sand.

[0027] KT: Temperature Co-factor. When the constant temperature of the water body is in the range of 25℃-28℃, the improvement of nitrification activity compared with the reference temperature (such as 20℃) is quantified. Based on the Arrhenius equation of nitrifying bacteria and experimental data, the value of KT can be set to 1.4-1.8, which is consistent with the temperature response characteristics of microbial metabolism.

[0028] KO is a dissolved oxygen synergist. When the dissolved oxygen content of the water body is in the range of 4 mg / L-6 mg / L, the promotion of nitrification rate by high dissolved oxygen conditions compared with normoxic conditions can be quantified. Based on the Monod kinetic equation, the value of KO can be set to 1.2-1.5, which can completely eliminate the oxygen limitation of nitrification reaction.

[0029] FC is the synergistic factor for circulation. When the water circulation frequency is in the range of 4-8 times / h, to quantify the advantages of high-frequency circulation in pollutant mass transfer and treatment frequency, the value of FC can be set to 1.5-2.5.

[0030] KT, KO, and FC are not simply multiplied by numerical values, but rather exhibit a significant coupled enhancement effect. Under the mass transfer enhancement effect of high-frequency circulation (FC), the improving effects of water temperature (KT) and dissolved oxygen (KO) on nitrification activity are further amplified. High-frequency circulation enables rapid transfer of ammonia nitrogen in the water to the surface of the nitrifying filter media. The constant temperature environment of 25-28℃ increases the metabolic rate of nitrifying bacteria, and high dissolved oxygen eliminates the oxygen limitation of the nitrification reaction. The synergistic effect of these three factors results in a much higher improvement in nitrification efficiency than the sum of the effects of optimizing a single parameter. Based on this, the volume of the microbial carrier filter media in this application can be reduced by more than 30%, thereby reducing the volume of the modular air-water backwashing multi-layer filter media cotton-free filtration device. This solves the problem of volume redundancy that makes it difficult to meet the small space requirements of household or small commercial aquariums (the volume of the accommodating cavity 3 used to house the filter equipment is generally less than 0.1m³). 3 )need.

[0031] For example, from a theoretical calculation perspective, this application uses M, LB, KT, KO, and FC values ​​of 0.4 g / day, 0.05 g / (L), and 0.05 g / (L) respectively. When the daily water volume is 1.6, 1.3, and 1.8, VR = M / (LB · KT · KO · FC) = 0.4 / (0.05·1.6·1.3·1.8) = 2.14L, while in the traditional design (KT = KO = FC = 1), VR = 8.0L. The volume of the microbial carrier filter media in this application is reduced by about 73% compared to the traditional design. From an engineering implementation perspective (considering the water flow distribution, biofilm development, and long-term stability in actual engineering), this application configures 18.5L of microbial carrier filter media in a 27L post-nitrification clear water chamber. Its actual treatment capacity is: Capacity = 18.5 × 0.187 ≈ 3.46g / day, which is 8.7 times the daily load (0.4g / day), providing a huge safety margin. Even with such a large safety margin, the volume of the microbial carrier filter media is still much smaller than the volume of filter media required by traditional designs to achieve the same treatment capacity (3.46 / 0.05=69.2L).

[0032] This application breaks through the limitations of traditional design models, innovatively proposing the configuration of a modular air-water backwashing multi-layer filter media filter device that eliminates the need for cotton replacement in household or small commercial aquariums. Relying on the air-water backwashing system to efficiently backwash the multi-layer granular filter media, it achieves maintenance-free and cotton-replacement-free operation, fundamentally freeing users from maintenance labor and avoiding the risk of water quality deterioration during travel. It purifies the water through the physical interception effect of the filter chamber with multi-layer granular filter media and the nitrification effect of the post-nitrification clearing chamber with microbial carrier filter media. Furthermore, it overcomes the limitations of traditional single-cycle purification designs, adopting a multi-cycle cumulative purification approach to achieve the desired purification level. It innovatively optimizes "water circulation frequency," "water temperature," and "dissolved oxygen content" to the target range and incorporates these target ranges into the volume design of the microbial carrier filter media. This eliminates the reliance on large-volume microbial carrier filter media to ensure purification effectiveness, resulting in a reduction (more than 30%) in the volume of the microbial carrier filter media and the entire filtration equipment. This makes it suitable for aquariums with a volume of less than 0.1m³ in both home and small commercial aquariums, while still fully meeting purification requirements. This solves the core contradiction of "high-efficiency purification, maintenance-free, and small size" for home and small commercial aquariums.

[0033] Furthermore, this application also quantitatively designs the particle size and laying thickness of the upper and lower filter media based on three aspects: "hydraulic loss," "contaminant interception capacity," and "stratification speed." The upper layer is a lightweight porous granular filter media with a particle size of 5mm-15mm and a laying thickness of 100mm-150mm; the lower layer is a granular filter media with a wet true density greater than 2.0g / cm³, a particle size of 1mm-1.5mm, and a laying thickness of 80mm-120mm. This design ensures, on the one hand, that the hydraulic loss of water flowing through the multiple layers of granular filter media is relatively small (hydraulic loss less than 0.5m) during filtration and backwashing, thus meeting the head requirements of household pumps and satisfying the needs of household aquariums. On the other hand, it ensures a low contaminant saturation rate during the cleaning cycle (less than 10% within a 3-day cleaning cycle), avoiding clogging. Furthermore, it ensures that the granular filter media is in a non-fully fluidized state during cleaning, allowing for rapid stratification and repositioning after cleaning, without disrupting the high circulation frequency of 4-8 times per hour. In other words, the filter media thickness and particle size parameters designed in this application are not empirical selections, but innovative designs made after simultaneously considering factors such as "hydraulic loss", "dirt interception capacity" and "stratification speed", achieving the synergistic technical effects of being suitable for household use, not easily clogging during cleaning cycles, and adaptable to high-frequency cycles.

[0034] For example, when using a filter media combination of 100-150mm volcanic rock and 80-120mm quartz sand, based on h=k·v·L, the hydraulic loss at a filtration rate of 8.33m / h can be calculated to be approximately 0.0625m≤0.5m, which is suitable for a household pump with a head of 0.5m-1.0m. Based on G=K·L·A·ρ, the saturation rate of the backwash cycle can be calculated to be less than 10% to avoid clogging. After testing, it is verified that the stratification can be completed within 2-3 minutes after backwashing, ensuring that the system can quickly resume high-frequency circulation filtration and meet the time utilization requirements of the design concept of "multiple cycles of cumulative purification to meet standards".

[0035] For aquariums of different volumes and loads, the volume of the microbial carrier filter media, the volume of the post-nitrification water purification chamber, and the thickness and particle size of the multi-layer granular filter media can be designed based on the above design logic, thereby quickly forming a series of product solutions.

[0036] Furthermore, the backwash system is configured such that the water consumption for a single backwash accounts for 10%-15% of the total volume of the aquarium's main tank, and the cumulative water consumption for weekly backwashes accounts for 20%-30% of the total volume of the aquarium's main tank. For example, for a 200L main tank, the water consumption for a single backwash is 20-30L, accounting for 10%-15%; with two backwashes per week, the cumulative water change is 40-60L, accounting for 20-30%. This design achieves water change during backwashing, saving water consumption and eliminating the need for a separate water change step, which is more conducive to simplifying operation and controller logic program settings.

[0037] Before use, the equipment needs to be configured: connect the filter equipment to the aquarium detachably through the standardized interface, ensure that the inlet and outlet of the filter module and the inlet of the backwash system are connected to the inside of the main tank of the aquarium, and ensure that the volume of the microbial carrier filter media in the post-nitrification clear water chamber is not less than the minimum volume calculated above.

[0038] When performing the filtration process, start the filter pump, open the inlet valve 1113 on the inlet pipe and the electric shut-off valve 1114 between the filter chamber and the post-nitrification clear water chamber, so that the water in the main tank of the aquarium is fully circulated based on the water circulation frequency. During circulation, the water flows through the buffer chamber, the upper filter media in the filter chamber, the lower filter media in the filter chamber, and the microbial carrier filter media in the post-nitrification clear water chamber before returning to the main tank of the aquarium. After being buffered in the buffer chamber, the water overflows from the top of the buffer chamber to the filter chamber, which can reduce the adverse effects of violent water disturbance on the activity of nitrifying bacteria.

[0039] When performing the air-water backwash process, close the inlet valve on the inlet pipe and the electric shut-off valve between the filter chamber and the post-nitrification water chamber. First, start the backwash fan for air washing, then start the backwash pump for combined air-water washing. During combined air-water washing, the water inside the main tank of the aquarium flows from bottom to top through the lower filter media and then the upper filter media in the filter chamber before being discharged. For example, a backwash wastewater overflow port can be provided on the top side wall of the filter chamber. The backwash wastewater overflow port should be higher than the highest water level in the filter chamber during filtration. A protective net should be installed at the backwash wastewater overflow port to prevent filter media from escaping. The buffer chamber has an independent wastewater collection tank, and the backwash wastewater overflow port is connected to the wastewater collection tank. The wastewater collection tank is equipped with a drain valve, allowing the backwash wastewater to be discharged through the drain valve.

[0040] In other words, the air-water backwashing process consists of a two-stage sequence: air washing and combined air-water washing. Specifically, an air wash can be performed for 2.0 to 5.0 minutes at an intensity of 5.0-9.0 L / (m²·s), followed by a combined air-water wash for 1.0 to 3.0 minutes at an intensity of 0.8-3.5 L / (m²·s) and an air-water ratio of 3.0:1-4.0:1. Under high dissolved oxygen (4 mg / L-6 mg / L) conditions, the disturbance to the water body caused by this intensity and duration has an acceptable impact on the nitrifying bacteria community (nitrifying bacteria survival rate >95%).

[0041] After backwashing, let it stand for 2-3 minutes to allow the filter media to separate into layers.

[0042] Both the electric shut-off valve and the inlet valve can communicate with the controller, which controls their opening and closing.

[0043] The filtration module can also be provided with an equipment chamber 1115, and the backwashing fan 121 and the backwashing pump 122 are both located inside the equipment chamber 1115. In the figure, the equipment chamber and the post-nitrification clear water chamber are located on the left side of the filtration chamber, and the equipment chamber is located behind the post-nitrification clear water chamber. The equipment chamber is an open chamber with an open rear side, which is convenient for the maintenance and repair of the equipment.

[0044] A perforated diversion plate can be provided at the top of the filtration chamber to ensure that water flows evenly through the multi-layer granular filter media. Exemplarily, the hole pitch of the perforated diversion plate can be 20 mm, and the hole diameter can be 8 mm.

[0045] A perforated support plate and a protective net can be provided between the lowermost filter media and the air-water distributor inside the filtration chamber. The perforated support plate supports the multi-layer granular filter media, and the protective net prevents the loss of granular filter media. The protective net can be a 20-mesh stainless steel net.

[0046] The air-water distributor 123 includes an air distribution pipe 123b and a water distribution pipe 123a. The air distribution pipe is provided with air-permeable holes with a diameter of Φ1 - 3 mm and an inclination angle of 30 - 60° upward, and the water distribution pipe is provided with water-permeable holes with a diameter of Φ4 - 6 mm and downward. The water distribution pipe is located below the air distribution pipe. In the figure, four air distribution pipes are provided, which are arranged roughly in a "king" shape, and four water distribution pipes are provided, which are also arranged roughly in a "king" shape.

[0047] A guide plate 1116 is provided inside the post-nitrification clear water chamber. The guide plate 1116 divides the post-nitrification clear water chamber into multiple sub-nitrification chambers. Microbial carrier filter media are provided in each sub-nitrification chamber. For two adjacent sub-nitrification chambers, one has an inlet at the upper part and an outlet at the lower part, and the other has an inlet at the lower part and an outlet at the upper part. In this way, when water flows through the post-nitrification clear water chamber, it can flow in a meandering manner, which is beneficial to increasing the contact area between water flow and microbial carrier filter media, and thus beneficial to improving the nitrification effect. For example, in Figure 2, three guide plates are arranged in sequence horizontally, and the first-stage sub-nitrification chamber, the second-stage sub-nitrification chamber, the third-stage sub-nitrification chamber and the fourth-stage sub-nitrification chamber are formed in sequence from left to right. The inlet of the first-stage sub-nitrification chamber is at the lower part, the inlet of the second-stage sub-nitrification chamber is at the upper part, the inlet of the third-stage sub-nitrification chamber is at the lower part, and the inlet of the fourth-stage sub-nitrification chamber is at the upper part. As shown by the arrow lines in the figure, after the water flows out of the filtration module 31, it flows through the first-stage sub-nitrification chamber, the second-stage sub-nitrification chamber, the third-stage sub-nitrification chamber and the fourth-stage sub-nitrification chamber in sequence and then returns to the main tank.

[0048] The backwashing fan can have an auxiliary aeration mode. In the auxiliary aeration mode, the backwashing fan is connected to the aeration device of the aquarium to serve as an aeration fan concurrently. After the backwashing is completed, the backwashing fan can be switched to the auxiliary aeration mode, which makes the machine multi-functional and is more conducive to reducing costs and avoiding volume redundancy.

[0049] The controller can have an automatic mode and a manual trigger mode. In automatic mode, the air-water backwashing process is executed based on a preset cycle. In manual trigger mode, the air-water backwashing process is executed based on a manual trigger command.

[0050] In summary, this application offers the following technical advantages: it solves the pain point of "frequent disassembly, cleaning, or replacement of filter components," enabling fully automatic, unattended operation, fundamentally freeing users from maintenance labor, mitigating the risk of water quality deterioration during travel, and, by combining a "constant temperature, high dissolved oxygen environment" and a "multi-frequency circulation purification concept," significantly reducing the size of the cleaning device (by more than 30%), making it suitable for aquariums smaller than 0.1m. 3 The chamber space is large, and the cleaning effect fully meets the requirements: the removal rate of suspended solids (TSS) is over 92%, the ammonia nitrogen degradation rate is ≥95%, the particulate filter media regeneration rate is ≥96%, and the overall energy consumption is low and the power of electrical components meets the requirements for household use.

[0051] To illustrate the above technical effects more intuitively, a specific example is given below: The total volume of the buffer chamber, filter chamber, and post-nitrification water chamber of the filtration module is 0.0945 m³, the main tank volume is 200 L, the water temperature is 25℃, the dissolved oxygen content is 4 mg / L-6 mg / L, and the filter pump has a rated flow rate of 1000 L / h and a circulation frequency of 5 times / h. The buffer chamber measures 100 mm × 300 mm × 450 mm and is equipped with a thermostat to maintain the water temperature at 25℃. The filter chamber measures 400 mm × 300 mm × 400 mm and contains 120 mm thick volcanic rock filter media with a particle size of 5-15 mm and a wet true density of 1.2 g / cm³. Below this is an 80 mm thick quartz sand filter media with a particle size of 1-1.5 mm and a wet true density of 2.6 g / cm³. The density difference between the upper and lower layers is 1.4 g / cm³, meeting the requirement of ≥1.0 g / cm³. The post-nitrification water purification chamber measures 300mm × 200mm × 450mm and contains a microbial carrier filter media. This filter media is porous granular, such as ceramsite, quartz balls, Kaldnes K1 packing material, or a mixture thereof. In this embodiment, a 1:1 volume ratio of ceramsite and quartz balls is used as an exemplary scheme to balance specific surface area and water flow distribution uniformity. 18.5L of microbial carrier filter media is used, resulting in an effective reaction water volume of 7.4L. The backwash fan is 30W with an air flow rate of 80L / min. The backwash pump is 40W with a flow rate of 300L / h and a 3-day backwash cycle. During backwashing, the system first performs an air wash at an intensity of 5.0-9.0 L / (m²·s) for 2.5-3.0 minutes, followed by a water wash at an intensity of 0.8-3.5 L / (m²·s) and an air-to-water ratio of 3.0:1-4.0:1 for 1.0-1.2 minutes. The backwash volume is 20-30L per cycle. After backwashing, the system is allowed to stand for 2-3 minutes to allow the filter media to stratify and return to their proper positions before resuming normal filtration. Throughout the backwashing process, the thermostat in the buffer chamber continuously operates to maintain a stable water temperature of 25℃, preventing temperature fluctuations from impacting the activity of nitrifying bacteria and ensuring that the system can quickly return to a stable filtration state after backwashing. Simultaneously, the wastewater from each backwash is directly discharged through the drain valve, achieving a "backwash and water change" coupling effect without the need for manual water changes, further reducing maintenance costs.

[0052] Design effectiveness assessment: Based on the above design parameters and collaborative model, the expected performance of this embodiment is evaluated: Treatment capacity assessment: Under the action of synergistic factors (KT=1.6, KO=1.3, FC=1.8), the theoretical daily treatment capacity of 18.5L microbial carrier filter media is 3.46g / day, which is 8.7 times that of the typical daily load (0.4g / day). In terms of capacity, it can ensure that the ammonia nitrogen removal rate can reach more than 95%.

[0053] Filtration effect calculation: Based on the multiple-cycle cumulative compliance model, at a cycle frequency of 5 times / hour, the system can reduce the ammonia nitrogen concentration to below 0.25 mg / L within 12 hours, meeting the requirements for long-term stable operation.

[0054] Volume Comparison: The total volume of the filter module in this embodiment is 0.0945m³, which is about 30% smaller than the typical volume of the filter system that comes with a mainstream 200L aquarium on the market (about 0.13-0.15m³).

[0055] Backwashing efficiency calculation: Based on the filter media dirt-holding capacity model, the dirt-holding saturation rate is less than 10% within a 3-day backwashing cycle, and the stratification can be completed within 2-3 minutes after backwashing, proving the rationality of the backwashing parameter design.

[0056] The above examples illustrate the principles and implementation methods of this application. The descriptions of the embodiments are merely for the purpose of helping to understand the methods and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of this application.

Claims

1. A modular air-water backwash multi-layer filter material without cotton replacement filter device, characterized in that, The filter device is a separate device provided with a standardized interface, and can be detachably connected with the aquarium through the standardized interface. The filter device comprises: A filter module, the water inlet and outlet of which can be communicated with the inside of the main cylinder of the aquarium through the standardized interface, comprising a filter pump, a buffer cavity, a filter cavity and a post-nitrification clean water cavity arranged in sequence along the water flow direction, a plurality of layers of granular filter materials are arranged in the filter cavity, the plurality of layers of granular filter materials comprise at least two layers of granular filter material layers with different wet true densities, the wet true densities of the adjacent two layers of filter materials increase in turn from top to bottom, and the difference in wet true density is greater than or equal to 1.0 g / cm³, so as to realize automatic layering and returning after backwashing through the density difference, and a microbial carrier filter material is arranged in the post-nitrification clean water cavity; A backwashing system, the water inlet of which can be communicated with the inside of the main cylinder of the aquarium through the standardized interface, comprising a backwashing fan, a backwashing pump and an air-water distributor located inside the filter cavity and below the lowermost layer of filter materials; A controller, which is configured to: control the water temperature, the water dissolved oxygen content and the water circulation frequency in a target range; calculate the minimum volume of the microbial carrier filter material according to the target range, and control the filling amount of the microbial carrier filter material in the post-nitrification clean water cavity or send a microbial carrier filter material filling prompt signal according to the minimum volume; perform a filter process based on the water circulation frequency and an air-water backwashing process based on a preset backwashing period.

2. The filter apparatus of claim 1, wherein, A thermostatic device is arranged in the buffer cavity, which is in communication connection with the controller, and is used to maintain the water temperature constant and the constant temperature in the target range. The controller can also be in communication connection with an aeration device of the aquarium, so as to maintain the water dissolved oxygen content in the target range by using the aeration device.

3. The filter apparatus of claim 1, wherein, The microbial carrier filter material is a porous granular microbial carrier filter material, which includes but is not limited to one or more of ceramsite, quartz ball and Kaldnes K1 filler.

4. The filter apparatus of claim 1, wherein, A backwashing wastewater overflow port is arranged at the top of the side wall of the filter cavity, which is higher than the highest water level of the filter cavity during filtration, and a protective net is arranged at the backwashing wastewater overflow port. An independent wastewater collection tank is arranged in the buffer cavity, the backwashing wastewater overflow port is communicated with the wastewater collection tank, and the wastewater collection tank is provided with a blowdown valve.

5. The filter apparatus of claim 1, wherein, The plurality of layers of granular filter materials comprise an upper layer of filter material with a particle size of 5-15 mm and a laying thickness of 100-150 mm, and a lower layer of filter material with a particle size of 1-1.5 mm and a laying thickness of 80-120 mm. The upper layer of filter material is a porous granular filter material, the lower layer of filter material is a granular filter material with a wet true density greater than 2.0 g / cm³, and the difference in wet true density between the upper layer of filter material and the lower layer of filter material is greater than or equal to 1.0 g / cm³.

6. The filter apparatus of claim 1, wherein, An equipment compartment is further arranged in the filter module, and the backwashing fan and the backwashing pump are located in the equipment compartment. An electric shut-off valve is arranged between the filter cavity and the post-nitrification clean water cavity, which is in communication connection with the controller, and is used to cut off the communication between the filter cavity and the post-nitrification clean water cavity during backwashing.

7. The filter apparatus of claim 1, wherein, The backwashing system is configured to: the water volume for single backwashing accounts for 10-15% of the total volume of the main cylinder of the aquarium; and the cumulative water volume for backwashing per week accounts for 20-30% of the total volume of the main cylinder of the aquarium.

8. The filter apparatus of claim 1, wherein, The air-water backwashing process comprises two-stage timing: first, air washing at an intensity of 5.0-9.0 L / (m²·s) for 2.0-5.0 minutes, and then combined air-water washing at an intensity of 0.8-3.5 L / (m²·s) and an air-water ratio of 3.0:1-4.0:1 for 1.0-3.0 minutes; after the backwashing is completed, standing for 2-3 minutes to make the filter material stratify and return to the original position.

9. The filter apparatus of claim 1, wherein, The air-water distributor comprises an air distribution pipe and a water distribution pipe, the air distribution pipe is provided with air permeable holes with a diameter of Φ1 mm-3 mm and an upward angle of 30°-60°, and the water distribution pipe is provided with water permeable holes with a diameter of Φ4 mm-6 mm and facing downward.

10. The filter apparatus of claim 1, wherein, The top of the filter cavity is provided with a perforated distribution plate, and a perforated support plate and a protective net are arranged between the lower layer of filter material and the air-water distributor inside the filter cavity.

11. The filter apparatus of claim 1, wherein, The backwashing air blower has an auxiliary aeration mode, in which the backwashing air blower is in communication with the aeration device of the aquarium; and the controller has an automatic mode and a manual trigger mode, in which the automatic mode is based on a preset period to execute the air-water backwashing process, and the manual trigger mode is based on a manual trigger instruction to execute the air-water backwashing process.

12. A filter method for an aquarium without changing cotton, characterized by, The filter device is realized based on any one of claims 1-11, and the filter method comprises the following steps: 1) Device configuration: detachably connecting the filter device to the aquarium through a standardized interface, ensuring that the water inlet and outlet of the filter module and the water inlet of the backwashing system are in communication with the inside of the main cylinder of the aquarium, combining the target range of the water temperature, water dissolved oxygen content and water circulation frequency, calculating the minimum volume of the microbial carrier filter material through a preset model, and ensuring that the volume of the microbial carrier filter material in the rear nitration clean water cavity is not less than the minimum volume; 2) Controlling the water temperature, water dissolved oxygen content and water circulation frequency to be in the target range; 3) Executing a filter process based on the water circulation frequency: starting the filter pump to make the water in the inside of the main cylinder of the aquarium circulate in full amount at the water circulation frequency, and when circulating, the water flows through the buffer cavity, the multiple layers of filter material in the filter cavity and the microbial carrier filter material in the rear nitration clean water cavity in turn and then returns to the inside of the main cylinder of the aquarium; 4) Executing an air-water backwashing process based on a preset backwashing period: first starting the backwashing air blower to perform air washing, and then starting the backwashing pump to perform combined air-water washing, and when performing the combined air-water washing, the water in the inside of the main cylinder of the aquarium flows through the multiple layers of granular filter material in the filter cavity in turn from bottom to top and then is discharged.

13. The method for cotton-free filter change for an aquarium of claim 12, wherein, The controller determines the minimum volume VR of the microbial carrier filter material through the following model: VR = M / (LB · KT · KO · FC). Wherein, M is a preset ammonia nitrogen daily load, LB is a reference load rate, KT is a temperature coordination factor, KO is a dissolved oxygen coordination factor, and FC is a circulation coordination factor, the temperature coordination factor KT, the dissolved oxygen coordination factor KO, and the circulation coordination factor FC are based on the target interval of the water temperature, water dissolved oxygen content, and water circulation frequency. The controller controls the filter material filling amount of the post-nitrification clear water cavity or sends a filter material filling prompt signal according to the VR value.

14. The method for cotton-free filter change for an aquarium of claim 13, wherein, The water circulation frequency is controlled to be 4-8 times / h, the water temperature is controlled to be constant, and the constant temperature interval is 25-28 DEG C; the water dissolved oxygen content is controlled to be 4-6 mg / L; the temperature coordination factor KT is 1.4-1.8, the dissolved oxygen coordination factor KO is 1.2-1.5, and the circulation coordination factor FC is 1.5-2.

5.

15. The method for cotton-free filter change for an aquarium of claim 12, wherein, The preset backwashing cycle includes a high load corresponding period and a regular load corresponding period, the high load corresponding period is 3-5 days, the regular load corresponding period is 10-15 days, first air washing at a strength of 5.0-9.0 L / (m2.s) for 2.0-5.0 minutes, then air-water combined washing at a water washing strength of 0.8-3.5 L / (m2.s) and a gas-water ratio of 3.0:1-4.0:1 for 1.0-3.0 minutes; after backwashing, standing for 2-3 minutes to make the filter material layered and returned.

16. The filter method without changing cotton for an aquarium according to claim 12, wherein the water consumption of single backwashing accounts for 10-15% of the total volume of the main cylinder of the aquarium, and the cumulative water consumption of backwashing per week accounts for 20-30% of the total volume of the main cylinder of the aquarium.

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