A large-flow adaptive ozone photocatalytic deodorization system

Abstract

The utility model provides a kind of large flow adaptive ozone photocatalysis deodorization system and method, belong to air purification technical field, wherein system mainly includes: air duct, and the pretreatment unit, ozone conversion unit, photocatalysis reaction unit and negative pressure control air unit fixedly installed in air duct along airflow direction from air inlet to air outlet in order;The system further includes sensing unit and controller;The sensing unit includes sensing unit one located in the ozone conversion unit upstream and sensing unit two located in the negative pressure control air unit downstream;The pretreatment unit, ozone conversion unit, photocatalysis reaction unit, negative pressure control air unit and sensing unit are electrically connected with the controller.This deodorization system and method can solve the problem of odor difficult to handle, complicated process, poor treatment effect in current breeding field.

Description

Technical Field

[0001] This utility model belongs to the field of air purification technology, specifically relating to a high-flow adaptive ozone photocatalytic deodorization system. Background Technology

[0002] UV photodeodorization, also known as photocatalytic deodorization, works by irradiating titanium dioxide with ultraviolet light, generating free radicals that decompose odor molecules. At room temperature, when light quanta with wavelengths below 253.7 nm irradiate nanoscale titanium dioxide particles, electrons in the valence band are excited by the light quanta and transition to the conduction band, forming free electrons. A positively charged hole is formed in the valence band, thus creating an electron-hole pair. Utilizing the oxidizing power of the generated hole and the reducing power of the free electron, molecules such as H₂O and O₃ accumulated on the surface react to produce highly oxidizing free radicals. These free radicals can decompose almost all organic substances.

[0003] In large-scale livestock farms, the air inside the sheds contains a large amount of moisture due to animals drinking, breathing, and defecating, as well as from evaporative cooling pads and floor cleaning. This damp environment breeds a large number of microorganisms, which, after long-term accumulation and decomposition, release large amounts of gases such as ammonia, hydrogen sulfide, and methanethiol. These gases not only have an unbearable odor, but prolonged exposure to such an environment can also directly damage the physiological systems of livestock, causing various diseases.

[0004] With technological advancements and societal demands, the livestock industry has expanded unprecedentedly. Over the past decade, it has evolved from small-scale, decentralized farming to large-scale, automated operations, with pig farms now housing hundreds of thousands to millions of pigs, becoming the industry's mainstream (the same applies to chicken farming, especially egg-laying chickens). This dramatic increase in production efficiency has also brought serious environmental pollution problems, particularly the concentrated odor emissions from pig and chicken farms, which are increasingly polluting the air and have become a major pain point for the industry. Many leading companies' large-scale farms have faced complaints from nearby residents due to odor pollution, making normal production impossible or even forcing them to shut down. Therefore, the livestock industry now urgently needs high-efficiency, high-flow-rate deodorization equipment, which has become a pressing need. Many companies have made various attempts, resulting in several temporary solutions that are barely usable, but none have been able to effectively and fundamentally solve the problem.

[0005] Currently, the air deodorization technologies used in livestock farms include two main methods. One is the water-washing method using oxidant solutions to remove odors, such as the livestock deodorization system disclosed in CN216821176U, which is a commonly used method in animal husbandry and is essentially a water-washing deodorization process. The odor dissolves in water and then undergoes a chemical reaction, adding an extra dissolution step before the reaction begins, thus significantly reducing the deodorization effect; the deodorization efficiency is less than 50%. Furthermore, large amounts of hypochlorous acid and other chemical materials need to be added during the deodorization process.

[0006] Secondly, the photocatalytic deodorization equipment and control method disclosed in CN108722174B suffers from low efficiency due to the reliance on photocatalytic reactions alone. Its application is limited to low-volume environments, making it difficult to meet the ventilation demands of large-scale farms, which can reach hundreds of thousands to millions of cubic meters per hour. While multiple similar devices can be installed in large-scale farms to improve efficiency, cost undoubtedly becomes another major issue.

[0007] The two main solutions currently in use neither address the primary requirements of high efficiency and high throughput. This has led to a wait-and-see attitude across the industry, with no suitable solution for large-scale implementation. Consequently, the area around most farms remains unbearably smelly.

[0008] An analysis of the aforementioned patents and the conventional treatment methods currently used in farms reveals the following issues: 1. Balancing high flow rates with high treatment efficiency is challenging. Currently, livestock farms, such as large self-breeding and raising farms with 10,000 sows and an annual output of 300,000 fattening pigs, require a total ventilation volume of up to 90 million cubic meters per hour. Conventional, fixed-structure deodorization devices are prone to problems when handling high flow rates, such as slow reaction speeds, insufficient contact between reactants, airflow short-circuiting, and insufficient residence time. This leads to a sharp decline in treatment efficiency. Most existing solutions cannot meet the flow rate requirements, and a few fail to meet deodorization standards, with some achieving an efficiency of less than 50%.

[0009] 2. High operating costs. Traditional treatment methods such as oxidant washing require continuous consumption of large amounts of chemical reagents, large amounts of water supply, and generate large amounts of saturated wastewater. Traditional ozone deodorization often uses "overdosing" to ensure effectiveness, resulting in ozone waste. At the same time, in order to avoid secondary environmental pollution, additional consumables such as adsorption materials are required to treat excess ozone, which greatly increases costs and occupies a lot of space.

[0010] 3. Odor overflow causes secondary pollution to the environment; the deodorization system itself should not become a new source of pollution. Improper handling of environmental stress can lead to odor overflow from the farm, causing pollution to the external environment.

[0011] 4. The system cannot adapt to changing operating conditions. The amount and concentration of odor generated in a livestock farm are dynamic. A deodorization system operating at a fixed power level wastes energy at low concentrations and fails to completely remove odors at high concentrations. Utility Model Content

[0012] In view of this, this utility model proposes a high-flow adaptive ozone photocatalytic deodorization system, which can solve the problems mentioned in the background art regarding the treatment of odor in livestock farms.

[0013] This utility model specifically provides a high-flow adaptive ozone photocatalytic deodorization system, which includes an air duct and a pretreatment unit, an ozone conversion unit, a photocatalytic reaction unit, and a negative pressure air control unit that are fixedly installed sequentially from the air inlet to the air outlet along the airflow direction in the air duct; the system also includes a sensing unit and a controller. The sensing unit includes a first sensing unit located between the pretreatment unit and the ozone conversion unit, a second sensing unit located between the negative pressure air control unit and the air outlet, and multiple ozone sensors and negative pressure sensors located inside the air duct; the first sensing unit is used to detect the inlet air velocity, ammonia concentration, and H2S concentration; the second sensing unit is used to detect the air velocity, ozone concentration, H2S concentration, and ammonia concentration of the treated gas; The ozone conversion unit consists of multiple ozone converters, which are regularly arranged within the air duct; there is at least one photocatalytic reaction unit within the air duct. The pretreatment unit includes a filter screen fixedly installed at the air inlet of the air duct, and an electrostatic dust removal system located downstream of the filter screen. The controller is based on a PLC and centrally controls the pretreatment unit, ozone conversion unit, photocatalytic reaction unit, sensing unit, and negative pressure air control unit. The ventilation duct adopts a closed tunnel structure with openings at both ends.

[0014] The beneficial effects of adopting the above technical solution are as follows: By setting up an air duct structure and using a negative pressure air control unit to achieve a negative pressure environment throughout the air duct, it is ensured that odors, ozone, and other intermediate products will not overflow into the atmosphere and cause air pollution during the deodorization process.

[0015] By setting up sensor unit one and sensor unit two, the gas content at the air duct inlet and outlet is detected simultaneously. The power of the ozone conversion unit and the negative pressure air supply unit in the system is jointly adjusted based on the sensor data of the two units, thereby controlling the deodorization efficiency of the system.

[0016] Ozone is generated by setting up an ozone conversion unit, and then used in a photocatalytic reaction unit with electron-hole pairs to eliminate odorous gases. In the photocatalytic reaction, ozone can also accelerate the photocatalytic process by absorbing some photogenerated electrons, resulting in a synergistic effect far greater than the sum of its parts (1+1>2) compared to using ozone or photocatalysis alone. This combined ozone and photocatalysis approach fully utilizes the characteristics and advantages of both. The generated ozone also significantly promotes the photocatalytic reaction, making this solution significantly superior to using ozone or photocatalysis alone.

[0017] While deodorizing, the equipment can also disinfect the gaseous environment, effectively killing some viruses that are transmitted through the air, cutting off the airborne transmission route of viruses, and avoiding impact on the surrounding environment of the farm.

[0018] By setting up a negative pressure air control unit, negative pressure is maintained inside the tunnel, which promotes the removal of reaction products from the catalyst surface and facilitates continuous reaction.

[0019] By setting up filters and an electrostatic dust removal system, the air drawn into the duct is initially filtered, removing most of the animal hair and dust from the air. This prevents the subsequent catalyst from being covered by dust and becoming inactive, effectively ensuring deodorization efficiency.

[0020] Furthermore, the photocatalytic reaction unit includes a light-illuminating layer and a catalyst layer. The catalyst layer is a multi-layered rigid porous plate or metal mesh surrounding the light-illuminating layer, and its surface is coated with a nano-photocatalyst. The illumination layer is composed of ultraviolet lamps with wavelengths from 150 nanometers to 380 nanometers, and the ultraviolet lamps are U-shaped or rod-shaped. The arrangement interval between the combined structure of the light-emitting layer and the catalyst layer is 50 mm to 400 mm.

[0021] Furthermore, the sensing unit one includes a wind speed sensor one for detecting the intake air speed and a gas sensor one for detecting the concentrations of ammonia and hydrogen sulfide. The second sensing unit includes a wind speed sensor for detecting the outgoing wind speed and a gas sensor for detecting the concentrations of ozone, ammonia, and hydrogen sulfide.

[0022] Furthermore, the controller is configured to: When the ammonia concentration detected by the sensing unit is less than or equal to 20 ppm or the hydrogen sulfide concentration is less than or equal to 6.6 ppm, the ozone converter in the ozone conversion unit is controlled to shut down sequentially. When the ammonia concentration detected by the sensing unit is greater than 30 ppm or the hydrogen sulfide concentration is greater than 10 ppm, the ozone converter that has been turned off is turned on one by one. When the ozone concentration detected by the second sensing unit is greater than 0.1 ppm, the controller shuts down all ozone converters.

[0023] Furthermore, the negative pressure air control unit includes a fan, and the controller is configured to: When the wind speed detected by the second sensor unit is greater than 2.8 m / s, the operating frequency of the fan is controlled to decrease by a preset step size until the wind speed drops to 2 m / s. When the wind speed detected by the second sensing unit is less than 1.6 m / s, the operating frequency of the fan is controlled to increase by a preset step size until the wind speed rises to 2 m / s.

[0024] Furthermore, the nano-photocatalyst is nano-titanium oxide, and it is doped with one of manganese oxide, tungsten oxide, iron oxide, vanadium oxide, cerium oxide, copper oxide, and carbon powder.

[0025] Furthermore, the catalyst layer is made of one of the following materials: silicon carbide, alumina, metal, ceramic, or plastic. When the catalyst layer is a porous plate, the number of layers is 2 to 65, the thickness of each layer is 0.5 to 30 mm, and the porosity is between 15% and 95%. When the catalyst layer is a metal mesh, the metal mesh is woven from iron, aluminum or copper wires of 0.2 mm to 1.5 mm, and the mesh pores are between 1 mm and 10 mm; or it is a diamond-shaped metal mesh cut and stretched from a metal plate, in which case the mesh pores are between 1 mm and 14 mm.

[0026] The beneficial effects of adopting the above-mentioned further technical solutions are: The catalyst layer used has small pores, and the surface of the mesh is coated with a catalyst. When air molecules pass through, ozone molecules, odor molecules, and some water molecules are adsorbed on the surface of the catalyst and aggregated, which greatly improves the contact probability and reaction efficiency.

[0027] Furthermore, the photocatalytic reaction unit is an independent module that can be completely disassembled and assembled.

[0028] A high-flow-rate adaptive ozone photocatalytic deodorization method based on the above system is applicable to deodorization treatment in large-scale farms. The method specifically includes the following steps: Step 1 Pre-treatment: Polluted air is drawn into the air duct through the negative pressure air control unit and then passes through filtration and electrostatic dust removal in sequence; Step 2 core reaction: The air pretreated in Step 1 is mixed with ozone generated by the ozone conversion unit precisely controlled by the controller to form an ozone mixed gas; the ozone mixed gas enters the photocatalytic reaction unit, where ozone molecules are oxidized and decomposed under ultraviolet light irradiation and the action of a catalyst; Step 3: Emission and Monitoring: The gas treated by the core reaction in Step 2 is discharged through the negative pressure ventilation control unit, while the composition and wind speed of the outlet gas are monitored in real time by the sensor unit 2. Step 4 Intelligent Control Closed Loop: Based on the monitoring data from sensor unit 2, the controller adaptively adjusts the wind speed of the negative pressure air control unit and the number and power of the ozone conversion unit that are started and stopped.

[0029] Compared with existing technologies, the beneficial effects of the deodorization system and method provided by this utility model are: 1. Highly efficient deodorization: By creating suitable reaction conditions and utilizing the synergistic effect of ozone and photocatalysis, the reaction rate and efficiency are greatly improved, exceeding that of conventional methods by 50%, and can quickly decompose a variety of odor molecules.

[0030] 2. High flow rate adaptive: The tunnel design and multi-layer catalytic layer support high airflow treatment, meet the high flow rate requirements of aquaculture farms, and adapt to different concentration changes through PLC control.

[0031] 3. Energy-saving and environmentally friendly: It consumes only electricity and no chemical materials; it makes full use of water vapor in the air to reduce water costs; the emitted gas meets environmental protection standards and there is no secondary pollution.

[0032] 4. Intelligent control: The PLC system automatically adjusts ozone production and fan speed based on real-time sensor data to ensure reaction balance, avoid energy waste, and extend equipment life.

[0033] 5. Prevent leakage: A high-flow-rate centrifugal fan is placed at the end of the system to maintain a stable negative pressure environment inside the entire treatment tunnel. This means that even if there are gaps in the system, outside air will seep in, rather than odors overflowing, fundamentally eliminating the risk of odor leakage.

[0034] 6. Low cost: No additional ozone removal device or water supply equipment is required, reducing maintenance and operating costs; the system has a simple structure and is easy to scale up.

[0035] 7. Highly targeted: It is particularly suitable for the environment of farms and can effectively treat complex odor components such as ammonia, hydrogen sulfide, and VOCs, solving industry pain points. Attached Figure Description

[0036] Figure 1 Overall structural diagram; Figure 2 This is a flowchart of the system processing. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the scope of the present utility model.

[0038] like Figure 1As shown, the high-flow-rate adaptive ozone photocatalytic deodorization system proposed in this utility model specifically includes: a pretreatment unit, an ozone conversion unit, a photocatalytic reaction unit, a sensing unit, a negative pressure air control unit, and an air duct; the pretreatment unit, ozone conversion unit, photocatalytic reaction unit, and negative pressure air control unit are sequentially fixedly installed in the air duct from the air inlet to the air outlet. The sensing unit is divided into two parts: sensing unit one and sensing unit two, where sensing unit one is located between the pretreatment unit and the ozone conversion unit; sensing unit two is located between the negative pressure air control unit and the air outlet.

[0039] Meanwhile, all of the above units are centrally controlled by a controller based on a PLC.

[0040] In particular, the number of photocatalytic reaction units can be increased or decreased according to the size of the farm.

[0041] Based on the above-mentioned structural facilities, this system has the following advantages: In terms of materials: the inherent water vapor in the air inside the breeding house is fully utilized as a reactant for the photocatalytic reaction, eliminating the need for additional humidification equipment or water sources, which significantly reduces material costs and system complexity.

[0042] In terms of energy and ozone management: ozone production is precisely adjusted through adaptive PLC control based on multi-sensor feedback, achieving "on-demand supply" and ensuring that ozone is completely consumed in the process. This not only saves electricity for oxygen production but also eliminates the need for expensive independent ozone removal devices, thus saving at least 15% of manufacturing costs; while the cost of replacing adsorption catalysts would increase the operating cost by at least 1%.

[0043] The pretreatment unit mainly consists of two parts: filtration and electrostatic dust removal. The air entering the duct undergoes initial filtration via a filter and electrostatic dust removal system to prevent dust and other impurities from covering the subsequent catalyst, which could prevent the photocatalytic reaction unit from generating electron-hole pairs properly. The filter is fixedly installed at the air inlet of the duct, while the electrostatic dust removal system is located inside the duct, close to the filter.

[0044] The air duct is a closed tunnel with openings at both ends. The airflow path is direct, the resistance is low, and it is suitable for handling large flow rates.

[0045] The ozone conversion unit mainly consists of multiple ozone converters arranged regularly within the air duct. A sensing unit is also installed between the ozone converters and the electrostatic precipitator system. This sensing unit primarily includes multiple wind speed sensors, an ammonia sensor, and an H2S sensor, used to detect the inlet air velocity and the concentrations of ammonia and H2S in the inlet air.

[0046] The photocatalytic reaction unit includes a catalytic layer and a light-illuminating layer. The catalytic layer provides electron-hole pairs for the photocatalytic reaction, enabling the decomposition of ammonia and other organic compounds in the odorous gas. The light-illuminating layer provides light of a specific wavelength required for the photocatalytic reaction.

[0047] The catalyst layer is mainly composed of multiple layers of rigid porous plates or metal mesh, while the illumination layer consists of ultraviolet lamps. The catalyst layer surrounds the illumination layer and is coated with catalysts such as nano-titanium oxide.

[0048] The illumination layer consists of ultraviolet lamps with wavelengths ranging from 150 nanometers to 380 nanometers, and the ultraviolet lamps are U-shaped or rod-shaped. The arrangement interval between the light-emitting layer and the catalyst layer in the combined structure is 50 mm to 400 mm.

[0049] The catalyst coating method on the catalyst layer surface is as follows: Nano-titanium oxide powder is mixed with water or alcohol solution and coated onto the porous material using brushing, roller coating, spraying, or dip coating methods, ensuring uniform coverage. One or more materials selected from manganese oxide, tungsten oxide, iron oxide, vanadium oxide, cerium oxide, copper oxide, and carbon powder may be added to the nano-titanium oxide powder.

[0050] The photocatalytic reaction unit is a separate module that can be disassembled and reassembled as a whole, making it convenient for users to modify the equipment according to their specific needs.

[0051] The negative pressure air control unit includes a fan, which is fixedly installed near the air outlet to draw gas from the entire air duct and control the flow rate and direction of the gas in the air duct.

[0052] Sensing unit two includes multiple wind speed sensors, ozone sensors, H2S sensors, and ammonia sensors, which are used to detect the types and contents of gases after processing by this system.

[0053] In addition to sensor unit one and sensor unit two, the sensing unit also includes negative pressure sensors fixedly installed at various locations inside the air duct, and multiple ozone sensors one fixedly installed inside the photocatalytic unit. The multiple ozone sensors one are arranged in a regular pattern according to the gas flow direction inside the air duct.

[0054] The start-up and shutdown of the ozone converter should follow these principles: If the value of ammonia sensor 1 is less than or equal to 20 ppm, or the value of H2S sensor 1 is less than or equal to 6.6 ppm, the controller will shut down the ozone converter in sequence. If the value of ammonia sensor 1 is greater than 30 ppm, or the value of H2S sensor 1 is greater than 10 ppm, the closed ozone converter will be turned on sequentially. When the value of ozone sensor 2 is greater than 0.1 ppm, the controller shuts down all ozone converters.

[0055] When controlling the gas flow rate within the duct, the fan follows these basic principles: When the wind speed sensor detects a value greater than 2.8 m / s, the centrifugal fan frequency decreases by 2 Hz / cycle until the wind speed decreases to 2 m / s. When the wind speed sensor detects a value less than 1.6 m / s, the centrifugal fan frequency increases by 2 Hz / cycle until the wind speed increases to 2 m / s.

[0056] Optionally, both the filter and the dust collection box of the electrostatic dust removal system are plug-in installed for easy and quick replacement.

[0057] Optionally, the material of the catalyst layer can be one or more combinations of silicon carbide, alumina, metal, ceramic, plastic, iron oxide, and tungsten oxide; When the catalyst layer is a porous plate, the number of layers is 2 to 65, the thickness of each layer is 0.5 to 30 mm, and the porosity is between 15% and 95%. When the catalyst layer is a metal mesh, the metal mesh is woven or welded from iron, aluminum or copper wires of 0.2 mm to 1.5 mm, and the mesh pores are between 1 mm and 10 mm; or it is a diamond-shaped metal mesh cut and stretched from a metal plate; in this case, the mesh pores are between 1 mm and 14 mm.

[0058] like Figure 2 As shown, a high-flow-rate adaptive ozone photocatalytic deodorization method is also involved. This method is applicable to the above-mentioned system, and the method specifically includes the following steps: Step 1: Preprocessing stage Inhalation and primary filtration: Polluted air in the breeding shed is drawn in by the negative pressure fan at the end of the system and enters through the air inlet of the tunnel-type system, i.e., the air duct. It first passes through a replaceable primary filter to remove larger particles, hair, etc.

[0059] Electrostatic dust removal: The air, filtered through a filter, then enters the electrostatic dust removal system, where a high-voltage electric field adsorbs and removes fine dust and aerosols. This process prevents the subsequent catalyst from being covered in dust and becoming deactivated. It is also important to regularly clean the filters and dust collection boxes.

[0060] Step Two: Core Reaction Phase Precise ozone dosing: Pre-treated air enters an area consisting of multiple ozone converters. The number and power of these ozone converters are precisely controlled by a controller to produce sufficient but not excessive ozone, which mixes with the air to form an ozone mixture. The controller relies on data detected and fed back by sensor unit two to determine the number of ozone converters activated and their power during operation.

[0061] Photocatalytic oxidation reaction: Ozone-mixed gas enters the photocatalytic reaction unit. This unit consists of a porous catalyst layer coated with multiple nano-catalysts and an ultraviolet lamp. Under ultraviolet light irradiation, the catalyst generates photogenerated electrons and holes. Ozone, as a powerful electron absorber, captures electrons and greatly inhibits electron-hole recombination, thereby significantly improving photocatalytic efficiency and generating a large number of highly oxidizing hydroxyl radicals. After being adsorbed by the catalyst, ozone molecules accumulate on the surface and are rapidly oxidized and decomposed under the combined action of ozone and hydroxyl radicals.

[0062] Step 3: Emissions and Monitoring Phase Harmless emissions: The harmless gases produced at the end of the reaction, such as nitrogen, water, and carbon dioxide, are discharged into the atmosphere under the suction of a high-flow centrifugal negative pressure fan.

[0063] Real-time monitoring and feedback: Multiple sensors, including ammonia, hydrogen sulfide, ozone and wind speed sensors, are installed at key locations such as the system outlet to continuously monitor the treatment effect and equipment status.

[0064] Step Four: Intelligent Control Closed Loop Data analysis and decision-making: All sensor data is transmitted to the controller in real time.

[0065] Adaptive adjustment: The controller activates more ozone generators when the outlet ammonia level is >30ppm and increases the fan frequency when the wind speed is <1.6m / s, automatically adjusting the fan speed and controlling the airflow speed and residence time. At the same time, it controls the number of ozone converters to control the ozone concentration, forming a complete and adaptive intelligent control closed loop.

[0066] During the experiment, it was found that conventional water washing methods mainly utilize the solubility or chemical reaction of odor components in water or specific chemical absorbents for removal. For ammonia, acid solutions are typically used for absorption, generating ammonium salts. However, the rate at which gas transfers from the gas phase to the liquid phase is limited, and the overall system layout restricts the gas-liquid contact area. If the waste gas flow rate is large, the concentration fluctuates, or the spray tower is poorly designed, insufficient gas-liquid contact can occur, causing ammonia to pass through the scrubbing tower before it can be absorbed, ultimately resulting in an efficiency of less than 50%.

[0067] When ozone is used alone for deodorization, its strong oxidizing properties and the stability of ammonia (NH3) molecules mean that ozone preferentially reacts with other more reactive substances in the exhaust gas. This consumes a large amount of ozone, leaving less for ammonia. Furthermore, the mixed gas requires a certain reaction time for ozone to fully contact and react with odor molecules. Insufficient mixing time can also lead to poor deodorization.

[0068] When using photocatalysis for deodorization, the final products of ammonia oxidation are typically nitric acid or nitrous acid. These acidic substances are firmly adsorbed onto the active sites of the photocatalyst, leading to catalyst poisoning and deactivation. Once the active sites are occupied, the catalytic efficiency drops rapidly and is difficult to recover. Simultaneously, the photocatalytic reaction also requires pollutant molecules to diffuse to the catalyst surface. If the airflow within the equipment is poorly organized, most of the gas cannot reach the catalyst surface irradiated by ultraviolet light, significantly reducing efficiency.

[0069] Compared to the above, this solution utilizes an improved air duct and photocatalytic reaction unit, combined with an ozone generator, to effectively treat odors by comprehensively utilizing the strong oxidizing effect of ozone and the ultraviolet light irradiation of the photocatalyst. Simultaneously, this solution uses the negative pressure of the fan to remove the products of ammonia oxidation from the active sites of the photocatalyst, preventing catalyst poisoning and deactivation. When the ammonia concentration at the inlet is close to 100 ppm, the concentration at the outlet can be kept below 20 ppm or even below 10 ppm, achieving an odor treatment efficiency of 80-90%.

Claims

1. A high-flow-rate adaptive ozone photocatalytic deodorization system, characterized in that, include: The system includes an air duct and a pretreatment unit, an ozone conversion unit, a photocatalytic reaction unit, and a negative pressure air control unit, which are sequentially fixedly installed along the airflow direction from the air inlet to the air outlet within the air duct; the system also includes a sensing unit and a controller. The sensing unit includes a first sensing unit located between the pretreatment unit and the ozone conversion unit, a second sensing unit located between the negative pressure air control unit and the air outlet, and multiple ozone sensors and negative pressure sensors located inside the air duct; the first sensing unit is used to detect the inlet air velocity, ammonia concentration, and H2S concentration; the second sensing unit is used to detect the air velocity, ozone concentration, H2S concentration, and ammonia concentration of the treated gas; The ozone conversion unit consists of multiple ozone converters, which are regularly arranged within the air duct; there is at least one photocatalytic reaction unit within the air duct. The pretreatment unit includes a filter screen fixedly installed at the air inlet of the air duct, and an electrostatic dust removal system located downstream of the filter screen. The controller is based on a PLC and centrally controls the pretreatment unit, ozone conversion unit, photocatalytic reaction unit, sensing unit, and negative pressure air control unit. The ventilation duct adopts a closed tunnel structure with openings at both ends.

2. The high-flow-rate adaptive ozone photocatalytic deodorization system according to claim 1, characterized in that, The photocatalytic reaction unit includes a light-illuminating layer and a catalytic layer. The catalytic layer is a multi-layered rigid porous plate or metal mesh surrounding the light-illuminating layer, and its surface is coated with a nano-photocatalyst. The illumination layer is composed of ultraviolet lamps with wavelengths from 150 nanometers to 380 nanometers, and the ultraviolet lamps are U-shaped or rod-shaped. The arrangement interval between the combined structure of the light-emitting layer and the catalyst layer is 50 mm to 400 mm.

3. The high-flow-rate adaptive ozone photocatalytic deodorization system according to claim 1, characterized in that, The sensing unit 1 includes a wind speed sensor 1 for detecting the intake air speed and a gas sensor 1 for detecting the concentrations of ammonia and hydrogen sulfide. The second sensing unit includes a wind speed sensor for detecting the outgoing wind speed and a gas sensor for detecting the concentrations of ozone, ammonia, and hydrogen sulfide.

4. The high-flow-rate adaptive ozone photocatalytic deodorization system according to claim 1, characterized in that, The controller is configured to: When the ammonia concentration detected by the sensing unit is less than or equal to 20 ppm or the hydrogen sulfide concentration is less than or equal to 6.6 ppm, the ozone converter in the ozone conversion unit is controlled to shut down sequentially. When the ammonia concentration detected by the sensing unit is greater than 30 ppm or the hydrogen sulfide concentration is greater than 10 ppm, the ozone converter that has been turned off is turned on one by one. When the ozone concentration detected by the second sensing unit is greater than 0.1 ppm, the controller shuts down all ozone converters.

5. The high-flow-rate adaptive ozone photocatalytic deodorization system according to claim 1, characterized in that, The negative pressure ventilation control unit includes a fan, and the controller is configured to: When the wind speed detected by the second sensor unit is greater than 2.8 m / s, the operating frequency of the fan is controlled to decrease by a preset step size until the wind speed drops to 2 m / s. When the wind speed detected by the second sensing unit is less than 1.6 m / s, the operating frequency of the fan is controlled to increase by a preset step size until the wind speed rises to 2 m / s.

6. The high-flow-rate adaptive ozone photocatalytic deodorization system according to claim 2, characterized in that, The nano-photocatalyst is nano-titanium oxide, and it is doped with one of manganese oxide, tungsten oxide, iron oxide, vanadium oxide, cerium oxide, copper oxide, and carbon powder.

7. The high-flow-rate adaptive ozone photocatalytic deodorization system according to claim 2, characterized in that, The catalyst layer is made of one of the following materials: silicon carbide, alumina, metal, ceramic, or plastic. When the catalyst layer is a porous plate, the number of layers is 2 to 65, the thickness of each layer is 0.5 to 30 mm, and the porosity is between 15% and 95%. When the catalyst layer is a metal mesh, the metal mesh is woven from iron, aluminum or copper wires of 0.2 mm to 1.5 mm, and the mesh pores are between 1 mm and 10 mm; or it is a metal diamond mesh made by cutting and stretching a metal plate, in which case the mesh pores are between 1 mm and 14 mm.

8. The high-flow-rate adaptive ozone photocatalytic deodorization system according to claim 1, characterized in that, The photocatalytic reaction unit is an independent module that can be completely disassembled and assembled.

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