Fresh air handling unit integrated with regenerative vocs filter

Abstract

The utility model discloses a new fan unit of integrated regeneration VOCs filter, including main pipeline and set up inside gas pretreatment device, main pipeline is equipped with main filter and spare filter after gas pretreatment device, and two filters all include ultraviolet lamp and under ultraviolet light irradiation can decompose the adsorbed organic matter and realize the regeneration adsorption device, the clean gas of any filter can supply another filter and regenerate use, two filters filter and regenerate alternately, and the spare filter is located in the independent pipeline communication with main pipeline, and the main pipeline is equipped with a gate for cutting off main air duct in each side before and after main filter, and the communication valve of independent pipeline communication with main pipeline is located in two gate outer sides. The new fan unit can realize filter regeneration without shutdown.

Description

Technical Field

[0001] This utility model relates to air filtration devices, and more particularly to a fresh air handling unit with an integrated regenerable VOCs filter. Background Technology

[0002] In cleanroom environments with extremely high air quality requirements, such as semiconductor chip manufacturing, biopharmaceutical production, and precision electronic component manufacturing, even trace amounts of volatile organic compounds (VOCs) in the air can affect product quality and equipment precision during the production process. Therefore, as the first line of defense for cleanroom air quality, one of the core functions of a manual air handling unit (MAU) is to remove various pollutants from fresh air through a series of filtration devices. Among these, organic chemical filters play a crucial role in removing VOCs. Currently, in these application scenarios, traditional organic chemical filters are the mainstream equipment for VOCs treatment in fresh air handling units. Structurally, existing fresh air handling units typically consist of multiple functional sections connected sequentially, including an air inlet section, a pre-filter section, a cooling surface section, a heating section, a humidification section, a fan section, a medium- and high-efficiency filter section, and an organic chemical filter section, forming a closed air duct system. Fresh air enters from the inlet of the fresh air handling unit, passes through each functional section in sequence, and is then delivered to the clean room from the outlet. The organic chemical filter section is a key purification link, and its core component is the chemical filter element. These filter elements are mostly made of activated carbon, activated carbon fiber, molecular sieves, or adsorbent materials impregnated with specific chemical agents. For example, common activated carbon filters are filled with a rich microporous structure. These micropores have a huge specific surface area. When fresh air containing VOCs flows through the filter, VOCs molecules are adsorbed on the surface of the micropores due to van der Waals forces, hydrogen bonds and other forces, thereby achieving separation from the fresh air and purifying the fresh air. From a workflow perspective, when the fresh air unit is started, fresh air from outside enters the unit under the action of the fan. It first passes through a pre-filter to remove larger particles, then through cooling, heating, and humidification stages to adjust the air to a suitable temperature and humidity, before entering the chemical filtration stage for organic matter. In the chemical filtration stage, VOCs are captured by the adsorption material in the filter element. The purified fresh air then passes through a high-efficiency filter to further remove fine particles before being delivered to the cleanroom through the fresh air outlet to maintain positive pressure and air quality within the cleanroom.

[0003] Traditional organic chemical filters have limited adsorption capacity. Once the filter element reaches saturation with VOCs, it loses its purification ability and must be replaced to maintain the normal operation of the fresh air handling unit. Filter replacement requires purchasing new filters, increasing material costs; it also requires professional maintenance personnel, increasing labor costs accordingly. Furthermore, filter replacement often necessitates shutting down the fresh air handling unit, causing an interruption in the cleanroom's fresh air supply, which may temporarily degrade indoor air quality and disrupt normal production activities. While some fresh air handling units employ a backup filter design, allowing replacement of the main filter without shutting down the system, the backup filter still needs to be replaced once it becomes saturated. This only delays the replacement time and does not fundamentally solve the problems of high maintenance costs and potential air quality impact. Furthermore, if filter replacement is delayed due to maintenance negligence, a saturated filter not only fails to effectively remove VOCs, but the adsorbed pollutants may even be released again, causing secondary pollution and threatening the air quality of the cleanroom. Summary of the Invention

[0004] Purpose of the utility model: The purpose of this utility model is to provide a fresh air handling unit with an integrated regenerable VOCs filter that can regenerate the filter without shutting down the system.

[0005] Technical solution: The present invention discloses an integrated regenerable VOCs filter fresh air unit, comprising a main duct and an internal gas pretreatment device. The main duct is equipped with a main filter and a backup filter after the gas pretreatment device. Both filters include an ultraviolet lamp and an adsorption device that can decompose and regenerate adsorbed organic matter under ultraviolet light irradiation. The clean gas produced by any filter can be supplied to the other filter for regeneration. The two filters alternately perform filtration and regeneration.

[0006] By setting up main and backup filters, each filter integrates a UV lamp and a UV-regenerable adsorption device, making it regenerable and reusable. At the same time, the clean gas produced by one filter can be used for the regeneration process of the other filter. This allows the other filter to be regenerated while one filter is filtering, and the two filters alternate between filtering and regenerating. This eliminates the need to stop the system to replace filter elements, significantly reducing operation and maintenance costs. At the same time, it ensures the continuity and stability of the fresh air supply to the cleanroom and avoids the risk of secondary pollution caused by filter saturation.

[0007] Preferably, the backup filter is installed in a separate pipe connected to the main pipe.

[0008] This design physically isolates the backup filter from the main filter, facilitating independent control and maintenance, improving the system's modularity and operational flexibility, while reducing interference with the main airflow.

[0009] Preferably, the main duct has a gate for cutting off the main air duct on both the front and rear sides of the main filter; the connecting valve connecting the independent duct to the main duct is located outside the two gates.

[0010] This structure allows for seamless switching during main filter regeneration by closing the gate to cut off the main air duct and simultaneously guiding the airflow to the backup filter via the connecting valve, ensuring uninterrupted air supply and improving system reliability and ease of operation.

[0011] Preferably, the main pipe and the independent pipe are equipped with a purification air valve for connection, and the purification air valve is located behind the two filters and in front of the gate behind the main filter.

[0012] Because the purification air valve is located behind the two filters, it can introduce the clean gas produced by one of the filters into the other for regeneration, allowing the two filters to perform filtration and regeneration operations separately, thus improving the overall energy efficiency of the system.

[0013] Preferably, the main pipeline is equipped with an exhaust device for discharging the gas generated during the regeneration process between the main filter and the gate in front of it, and the independent pipeline is provided before the backup filter.

[0014] The dedicated exhaust device effectively prevents desorbed VOCs from re-entering the air supply system, eliminating the possibility of secondary pollution and improving the system's safety and environmental friendliness.

[0015] Preferably, the ultraviolet lamps are arranged on both sides of the adsorption device.

[0016] By installing ultraviolet lamps on both sides of the adsorption device, symmetrical irradiation is achieved, ensuring that ultraviolet light uniformly covers the adsorption material, which improves photolysis efficiency and regeneration effect, shortens regeneration time, and enhances the service life and overall performance of the filter.

[0017] Preferably, the adsorption device is mesh-like.

[0018] The adsorption device adopts a mesh structure, which increases the contact area with the airflow, improves the adsorption efficiency of VOCs, and facilitates ultraviolet light penetration, enhancing the desorption effect and further optimizing the overall performance of filtration and regeneration.

[0019] Beneficial effects: By setting up a main filter and a backup filter, each filter integrates a UV lamp and a UV-regenerable adsorption device. The two filters alternately filter and regenerate, eliminating the need to stop the machine to replace the filter element, significantly reducing operation and maintenance costs. At the same time, it ensures the continuity and stability of the fresh air supply to the clean room and avoids the risk of secondary pollution caused by filter saturation. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the fresh air handling unit; Figure 2 This is a schematic diagram of the filter structure. Detailed Implementation

[0021] As shown in the figure, the fresh air handling unit with integrated regenerable VOCs filter of this utility model includes a main duct 1 and a gas pretreatment device installed inside. The main duct 1 is equipped with a main filter 2 and a backup filter 3 after the gas pretreatment device. Both filters include an ultraviolet lamp 4 and an adsorption device 5 that can decompose and regenerate the adsorbed organic matter under ultraviolet light irradiation. The clean gas produced by any filter can be supplied to the other filter for regeneration. The two filters alternately perform filtration and regeneration.

[0022] The main duct 1 of the fresh air handling unit has a rectangular air duct structure, with a fresh air inlet 101 on the left and a fresh air outlet 113 on the right. The internal conventional functional sections are arranged sequentially along the airflow direction as gas pretreatment devices, specifically including a primary filter 102, a medium-efficiency filter 103, a heating coil 104, a precooling coil 105, a spray humidifier 106, a recooling coil 107, a reheating coil 108, a fresh air supply fan 109, an acidic chemical filter 110, an alkaline chemical filter 111, and a high-efficiency filter 112. The middle and rear sections reserve installation areas for the main filter 2 and the backup filter 3 as organic chemical filtration areas.

[0023] Both filters include a mesh adsorption device 5 and ultraviolet lamps 4 positioned on either side of it. The number and position of the ultraviolet lamps 4 can be adjusted as needed, as long as they can irradiate the adsorption device 5 as comprehensively as possible. The adsorption device 5 is made of a composite material of activated carbon, which can decompose organic matter under ultraviolet light irradiation, ultimately converting it into stable inorganic substances such as water and carbon dioxide. The purified gas then carries the adsorption device 5 away, achieving regeneration. The material of the adsorption device 5 is an existing material, and can be one of the materials listed in CN102861504B, CN203886410U, or CN104848443B. Both filters described in this invention are used for filtering VOCs.

[0024] Inside the main duct 1, there is a gate 7 on both the front and rear sides of the main filter 2 to cut off the main air duct. When the two gates 7 are closed, the gas to be filtered cannot pass through the main filter 2 for filtration. When the two gates 7 are open, the gas to be filtered can pass through the main filter 2 for filtration.

[0025] The backup filter 3 is installed in an independent pipe 6 connected to the main pipe 1. The connecting valve 8 connecting the independent pipe 6 and the main pipe 1 is located outside the two gate valves 7. When both connecting valves 8 are closed, the independent pipe 6 is cut off from the main pipe 1, and the gas to be filtered cannot flow through the independent pipe 6. When both are open, the main pipe 1 is connected, so that the gas to be filtered can be filtered through the backup filter 3 in the independent pipe 6. The two gate valves 7 open and close synchronously, and the two connecting valves 8 also open and close synchronously, but the opening and closing states of the gate valves 7 and the connecting valves 8 are opposite.

[0026] The main pipe 1 and the independent pipe 6 are equipped with a purification air valve 9 for connection. The purification air valve 9 is located behind the two filters and in front of the gate 7 behind the main filter 2.

[0027] The main pipeline 1 is provided with an exhaust device 10 for discharging the gas generated during the regeneration process between the main filter 2 and the gate 7 in front of it, and the independent pipeline 6 is provided with an exhaust device 10 in front of the backup filter 3. The exhaust device 10 includes an exhaust pipe and a fan (or other negative pressure device).

[0028] The working principle of the fresh air handling unit with integrated regenerative VOCs filter described in this invention is as follows: When the fresh air unit is operating normally, the gates 7 before and after the main filter 2 are fully open, and the main air duct is unobstructed; the connecting valve 8, the purification air valve 9, and the exhaust device 10 are all closed to block the gas flow. Fresh air enters from the inlet, is treated by the gas pretreatment device, and then enters the main filter 2 to adsorb VOCs. The purified fresh air (clean gas) is sent into the clean room from the fresh air outlet.

[0029] When the main filter 2 becomes saturated, the backup filter 3 is activated, and the main filter 2 is regenerated. The specific process is as follows: both gates 7 are closed, blocking the main air duct; the connecting valve 8, the purification valve 9, and the exhaust device 10 on the main duct 1 are all opened, while the exhaust device 10 on the independent duct 6 remains closed. Most of the fresh air enters the independent duct 6 through the front-end connecting valve 8, where it is adsorbed by the backup filter 3 and returns to the main duct 1 through the rear-end connecting valve 8. Fresh air is then delivered to the cleanroom from the fresh air outlet, ensuring normal air supply. Additionally, a small amount of fresh air (clean gas) is used for the regeneration of the main filter 2. This small amount of fresh air enters the main duct 1 through the purification valve 9, where the ultraviolet lamp 4 of the main filter 2 is activated to irradiate its adsorption device 5, decomposing organic matter. The clean gas, carrying pollutants generated during the regeneration of the main filter 2, is then discharged outdoors through the exhaust system.

[0030] Once the main filter 2 has completed regeneration and the standby filter 3 is saturated, fresh air is supplied through the main duct 1, and the standby filter 3 undergoes regeneration. The specific process is as follows: both gates 7 are fully open, ensuring unobstructed flow in the main duct 1; the connecting valve 8 and the exhaust device 10 on the main duct 1 are closed, while the purification valve 9 and the exhaust device 10 on the independent duct 6 are opened. Most of the fresh air is adsorbed by the main filter 2 to remove VOCs, and this fresh air is then supplied to the cleanroom from the fresh air outlet, ensuring normal air supply. A small amount of fresh air is used for the regeneration of the standby filter 3. This small amount of fresh air enters the independent duct 6 from the purification valve 9, where the ultraviolet lamp 4 of the standby filter 3 is activated to irradiate its adsorption device 5, decomposing organic matter and regenerating it. The clean gas, carrying the pollutants generated during regeneration, is discharged outdoors through the exhaust device 10 on the independent duct 6.

[0031] Through the above structural design and operation mode, based on the linkage control of the air valve, this invention realizes the seamless switching of "filtration-regeneration" of the chemical filter. The two VOCs chemical filters are regenerated alternately to ensure that at least one chemical filter is in an effective filtration state at any time. It realizes the in-situ regeneration of the filter, effectively solving the problems of high operation and maintenance costs of chemical filtration in traditional fresh air units and potential impact on indoor air quality. It is suitable for fresh air treatment in clean rooms and other places with strict air quality requirements.

Claims

1. A fresh air handling unit with an integrated regenerable VOCs filter, comprising a main duct (1) and a gas pretreatment device installed inside, characterized in that: The main pipeline (1) is equipped with a main filter (2) and a backup filter (3) after the gas pretreatment device. Both filters include an ultraviolet lamp (4) and an adsorption device (5) that can decompose the adsorbed organic matter under ultraviolet light irradiation to achieve regeneration. The clean gas produced by any filter can be supplied to the other filter for regeneration. The two filters alternately perform filtration and regeneration.

2. The fresh air handling unit according to claim 1, characterized in that: The backup filter (3) is installed in an independent pipe (6) connected to the main pipe (1).

3. The fresh air handling unit according to claim 2, characterized in that: The main pipe (1) has a gate (7) for cutting off the main air duct on both the front and rear sides of the main filter (2); the connecting valve (8) connecting the independent pipe (6) to the main pipe (1) is located outside the two gates (7).

4. The fresh air handling unit according to claim 3, characterized in that: The main pipe (1) and the independent pipe (6) are provided with a purification air valve (9) for connection. The purification air valve (9) is located behind the two filters and in front of the gate (7) behind the main filter (2).

5. The fresh air handling unit according to claim 3, characterized in that: The main pipeline (1) is provided with an exhaust device (10) for discharging the gas generated during the regeneration process between the main filter (2) and the gate (7) in front of it, and the independent pipeline (6) is provided with an exhaust device (10) in front of the backup filter (3).

6. The fresh air handling unit according to claim 1, characterized in that: The ultraviolet lamp (4) is arranged on both sides of the adsorption device (5).

7. The fresh air handling unit according to claim 1, characterized in that: The adsorption device (5) is mesh-like.

Images