KR20230148454A - Photocatalytic deodorizer based on activated carbon fiber - Google Patents

Abstract

The activated carbon fiber-based photocatalyst deodorizer of the present invention includes an optical module consisting of a wrinkled ACF-based photocatalyst sheet coated with a photocatalyst material, a mesh screen disposed on one side of the photocatalyst sheet and a plurality of LED arrays arranged, and A plurality of ventilation holes are punched in the valleys and ridges of the photocatalyst sheet as viewed from the flow direction, a first array of the plurality of LED arrays is arranged to irradiate toward the valleys of the corrugated sheet, and a second array is formed on the ridge. It is arranged to irradiate the back surface of the photocatalyst sheet through the ventilation hole.

Description

Photocatalytic deodorizer based on activated carbon fiber}

The present invention relates to an activated carbon fiber-based photocatalyst deodorizer in which a photocatalyst material is fixed to activated carbon fiber (ACF).

Air and water pollution is seriously destroying the Earth's ecosystem and threatening a sustainable environment. To overcome this, various means are being mobilized to not only fundamentally reduce pollutants such as zero carbon, but also realistically eliminate pollutants. Among them, technologies that purify air or water quality by decomposing various pollutants through direct sterilization using ultraviolet rays or photodecomposition of photocatalysts are receiving attention.

Conventionally, direct sterilization using ultraviolet rays is used in closed spaces for safety reasons, but it has the problem of generating ozone, which is harmful to the human body. In addition to direct sterilization by ultraviolet rays, photocatalytic materials activated by ultraviolet rays or visible rays are evaluated as an eco-friendly purification technology that decomposes microorganisms and harmful organic compounds into carbon dioxide and water through photodecomposition of organic matter. Photocatalyst is a combination of photochemistry and catalyst and refers to a catalyst that is activated by light energy. In particular, photocatalysts can be applied to various fields because they have strong oxidation and reduction power on the surface of the photocatalyst when activated, and have excellent organic matter decomposition functions, so they have the function of purifying the air and removing hazardous substances that are difficult to decompose in water. Photocatalyst materials include titanium dioxide (TiO2), zinc oxide (ZnO), cadmium sulfide (CdS), zirconium oxide (ZrO2), vanadium oxide (V2O2), tungsten oxide (WO3), and perovskite-type composite metal oxide (SrTiO3). etc.

Such photocatalytic materials can maintain high reactivity when the following three parameters, namely the photocatalyst carrier, light source, and purification target fluid, are fundamentally satisfied.

Ⅰ. Photocatalyst carrier

(1) The photocatalyst material must be effectively fixed to the support.

When used in powder form, photocatalyst materials have excellent photoactivity due to their high specific surface area. However, there is a disadvantage in that it is difficult to separate the photocatalyst powder from the fluid to be purified and recover it after purification. Therefore, photocatalyst materials are generally in the form of a thin film on a carrier. is fixed. Photocatalyst carriers include ceramics, activated carbon, glass, zeolite, stainless steel, and composite materials. Depending on the material or physical properties of the support, various photocatalyst thin film immobilization technologies are applied. Photocatalyst immobilization technologies include sol-gel method, dip coating, impregnation method, hydrothermal method, electrochemical method, chemical vapor deposition method, and electrophoretic deposition method.

The conventional dip coating method, which is generally used, involves a slurry coating process in which a carrier such as ceramic honeycomb is immersed in a slurry solution in which TiO2 powder such as DP25 is mixed with a binder and a dispersant, and then dried and fired. However, the photocatalyst powder is The specific surface area was lowered due to agglomeration during the coating process, resulting in low photoactivity, and even then, when exposed to ultraviolet rays for a certain period of time, the binder was decomposed and the photocatalyst material was detached from the carrier, causing durability problems such as loss of photocatalytic function.

(2) The shape of the carrier must be suitable for the flow path and optical path.

Since the photochemical reaction of a photocatalyst occurs at the photoactive sites of the photocatalyst, the shape of the carrier must be such that light can reach it and the fluid to be purified experiences less flow resistance. The form of the carrier includes flat, corrugated sheets, spherical beads, honeycomb, foam, non-woven fabric, wire mesh, etc. Generally, in the case of refrigerator sterilization and deodorizers, a honeycomb type is used, and in the case of air purifier photocatalyst sterilization and deodorizers, ceramic beads are used as a carrier.

(3) The photocatalyst material must be mesoporously fixed to the surface of the carrier to have a high specific surface area.

When grown in a nanoarray structure (nanowire, nanorod, nanotube, nanobelt, etc.) in which micropores and mesopores are hierarchically formed on a photocatalyst material fixed to a carrier, light absorption, This has the effect of increasing photoactivity because it is advantageous not only for the adsorption of the processing fluid but also for the diffusion of photochemical reactants.

Conventional photocatalyst reactors had problems in that the reactivity of the photocatalyst itself did not meet industrial demands due to a lack of coating technology, limitations in the selection of carriers, and a lack of mass preparation technology for nanostructured films.

Ⅱ. light source

The optical path is limited by the type and location of the light source and the shape of the carrier. The light source must be arranged so that the light from the light source is efficiently irradiated to the surface of the photocatalyst structure.

(1) Type of light source

Light sources are classified into sunlight and artificial light (point light sources, surface light sources), and are classified into ultraviolet rays, visible rays, and infrared rays depending on the wavelength. UV light is generally used as artificial light, but when using sunlight with less than 5% ultraviolet rays, a visible light-reactive photocatalyst material is preferable, and UV LEDs are more advantageous for commercialization than UV lamps in terms of the lifespan of the light source and freedom of shape.

(2) Location of light source

The location of the light source may be within or outside the flow path to be purified. In the case of a thick ceramic honeycomb, the light path may be blocked in the middle of the honeycomb channel, so the light source can be placed on both sides of the ceramic honeycomb, and in the case of a cylindrical foam, the light source can be placed in the center of the cylinder.

Ⅲ. Flow path of purification target (gas or liquid)

Since the photochemical reaction of the fluid to be purified occurs on the photoactivated surface of the photocatalyst structure, the flow path must be designed so that the fluid to be purified sufficiently and uniformly contacts the photocatalyst surface. On the other hand, considering the hourly throughput of the fluid to be purified, the flow path must be optimized to ensure sufficient contact while minimizing the flow resistance caused by the photocatalyst carrier.

As shown in Figure 1, the conventional photocatalyst structure includes a pre-filter that removes dust or fluff in the contaminated gas, a photocatalyst structure that performs a deodorizing or sterilizing function by a photocatalyst material, and a light irradiating the photocatalyst structure with light. The modules and dedicated fans that flow the gas are arranged in sequence. In the case of a refrigerator deodorizer, the pre-filter is a simple function that filters out dust or mold, but in the case of an air purifier, a plurality of various dust collection filters and HEPA filters can be arranged depending on the size or type of particles to be filtered. Depending on the usage environment, the optical module may be arranged on at least one side of the photocatalyst structure. For example, in the case of a large-capacity air purifier, they are arranged on both sides, and in the case of a refrigerator sterilizing deodorizer, they are arranged on one side.

As shown in Figure 2a, conventional photocatalytic deodorizers for refrigerators are generally used by coating honeycomb-shaped activated carbon or ceramic with a photocatalytic material. However, the adsorption power of odorous substances or bacteria is weak, so rare gases in the ppb unit (e.g., methyl mercaptan) are used. etc.), the deodorizing performance is insufficient, and the binder used to fix the photocatalyst material is deteriorated by UV light, causing a problem of detachment of the photocatalyst material. This ultimately results in the photocatalyst deodorizer having to be replaced during use due to durability issues. Additionally, in the case of a honeycomb filter, as the channel diameter becomes smaller or the length increases, it becomes more difficult to coat the inside of the channel with a photocatalyst, and the amount of light reaching the inside of the channel decreases. Therefore, in order to secure a constant amount of light inside the channel, the thickness of the honeycomb (i.e., the length of the channel) and the diameter of the channel must be limited.

In addition, in the case of a pleated filter as shown in Figure 2b, specific chemicals are impregnated on general activated carbon to remove acidic gases such as hydrogen sulfide, sulfur dioxide, and mercaptans, and to remove alkaline gases such as ammonia and methylamine. It is common to use it as a deodorizing filter by attaching it between microfiber non-woven fabrics. If this deodorizing filter loses its adsorption function after being used for a certain period of time due to adsorption supersaturation of the powdered activated carbon, it must be replaced as there is a risk of microbial growth or odor generation. In the case of pure activated carbon fiber (ACF) felt, the thickness varies from 1 to 10T, and has an adsorption speed of 10 to 100 times that of activated carbon and an adsorption capacity of more than 10 times that of activated carbon. It is shaped by treating non-woven fabric on both sides of ACF or using a binder. It is used as an adsorption filter for deodorizing and discoloring. These ACF-based deodorizing filters generally lose their adsorption function due to adsorption supersaturation after being used for a certain period of time, and must be replaced as there is a risk of microbial growth or odor generation. To solve this problem, a functional ACF filter can be manufactured through silver nano treatment or photocatalyst coating on pure ACF felt. However, when coating photocatalyst materials on ACF felt, it is difficult to find cases of ACF being used as a photocatalyst wrinkle filter due to new parameters such as optimization of the optical path of UV light or gas flow path design, and efficient coating of photocatalyst materials.

On the other hand, in the case of a bead-type structure as shown in Figure 2c, the photocatalyst material is uniformly formed on the surface of a bead of ceramic, zeolite, etc. using FB CVD or LBL CVD deposition technology, and a complex layer is stacked and packed in a mesh screen case to a certain thickness. Although it is manufactured through a process, it has less flow resistance than a wrinkle-shaped support, so it is used as a photocatalyst support in air purifiers and water purifiers. However, in the case of such photocatalyst beads, it is not economical to secure fluidity, and, like honeycomb photocatalyst modules using slurry coating, there are problems of short durability and low reactivity.

Therefore, activated carbon fiber felt, which has the highest adsorption amount and speed of odorous substances, is used as a photocatalyst carrier, while maximizing light absorption through efficient arrangement of the light source and photocatalyst deodorization to minimize the pressure drop (flow resistance) of polluting gases. There is a need to dramatically improve the composition of the device.

Republic of Korea Patent No. 10-1887621 Republic of Korea Patent No. 10-2138163

The present invention was created to solve the above-described conventional problems. The purpose of the present invention is to provide an activated carbon fiber-based photocatalyst deodorizer that reduces the flow resistance of activated carbon fiber and increases the contact time between the photocatalyst surface and polluting gas. The purpose is to provide.

In order to achieve the above object, the activated carbon fiber-based photocatalyst deodorizer provided according to the first embodiment of the present invention includes a wrinkled ACF-based photocatalyst sheet coated with a photocatalyst material, disposed on one side of the photocatalyst sheet, and a plurality of LED arrays. It includes an optical module composed of arranged mesh screens, a plurality of ventilation holes are punched in the valleys of the photocatalyst sheet viewed from the gas flow direction, and the plurality of LED arrays are arranged to irradiate toward the valleys of the corrugated sheet. It is characterized by

The ACF-based photocatalyst deodorizer provided according to the second embodiment of the present invention is an optical module consisting of a wrinkled ACF-based photocatalyst sheet coated with a photocatalyst material and a mesh screen disposed on one side of the photocatalyst sheet and having a plurality of LED arrays arranged. A plurality of ventilation holes are punched in the valleys and peaks of the photocatalyst sheet as viewed from the gas flow direction, a first array of the plurality of LED arrays is arranged to irradiate toward the valleys of the corrugated sheet, and a second LED array includes The array is arranged to irradiate the back surface of the photocatalyst sheet through a ventilation hole formed in the floor.

The ACF-based photocatalytic deodorizer of the present invention exhibits a rapid deodorizing effect by utilizing the excellent adsorption speed of ACF and can prevent adsorption saturation through photocatalysis, thereby maintaining the performance of the photocatalytic deodorizer semi-permanently.

In addition, according to the second embodiment of the ACF-based photocatalyst deodorizer of the present invention, the back side of the photocatalyst sheet can be irradiated through the ventilation hole formed at the bottom of the corrugated photocatalyst sheet, so both sides of the photocatalyst sheet can be irradiated with only one optical module. can do. As a result, both the front and back surfaces of the photocatalyst sheet can be used as photoactive sites.

Figure 1 is a schematic diagram showing the arrangement of components of a conventional photocatalytic deodorizer.
Figures 2a to 2c show types of existing deodorizer filters, with Figure 2a showing a ceramic honeycomb, Figure 2b showing a pleated sheet, and Figure 2c showing a ceramic ball bead.
Figure 3 is a perspective view showing the overall appearance of a wrinkled photocatalyst sheet designed according to the first embodiment of the present invention.
FIG. 4A is a plan view of the wrinkled photocatalyst sheet shown in FIG. 3 showing the arrangement of the ventilation holes, and FIG. 4B is a longitudinal cross-sectional view of the photocatalyst deodorizer of the present invention in which the optical module and the photocatalyst sheet are combined, including the LED array and the valley ventilation holes. shows the array.
Figure 5a is a plan view of the photocatalyst sheet according to the second embodiment showing the arrangement of ventilation holes additionally formed at the bottom of the corrugated sheet, and Figure 5b is a longitudinal cross-sectional view of the photocatalyst deodorizer of the present invention in which the optical module and the photocatalyst sheet are combined. , shows the arrangement of the LED array and ventilation holes.
Figure 6 is a plan view of an optical module in which a plurality of LED arrays are arranged on a mesh screen.

Hereinafter, with reference to the attached drawings, preferred embodiments that enable those skilled in the art to easily practice the present invention will be described in detail. However, when explaining in detail the operating principle of a preferred embodiment of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

In addition, the same reference numerals are used for parts that perform similar functions and actions throughout the drawings.

In addition, when a part is said to be "connected" to another part throughout the specification, this includes not only cases where it is directly connected, but also cases where it is indirectly connected through other components in between. In addition, “including” a certain component does not mean excluding other components, unless specifically stated to the contrary, but rather means that other components may be further included.

Figure 3 is a perspective view showing the entire ACF-based corrugated sheet 100 designed according to the first embodiment of the present invention. The corrugated sheet is coated with a known photocatalyst material. The pleated sheet has a structure in which the valleys 102 and ridges 104 are repeated, and the back side of the pleated sheet can be treated with non-woven fabric on both sides, standardized through binder treatment, or supported on the back side of the pleated sheet with a holder described later.

Figure 4a shows the plane of the corrugated sheet, and a plurality of ventilation holes 110 are perforated in the valley 102 to reduce gas flow resistance. As the gas flows in the direction of the valley, it becomes a vortex and increases the contact time with the ACF surface. As shown in Figure 4b, an optical module 400 is placed adjacent to the crest 104 of the pleated sheet 100, and an LED array 410a is fixed to the mesh screen of the optical module so as to illuminate the valley direction of the pleated sheet. Optionally, a holder is placed in close contact with the rear surface of the pleated sheet 100 to hold the pleated sheet in place. The pleated sheet and optical module are fixed in place using the frame 300. The corrugated sheet 100 is properly fixed to the fixing part 310 of the frame 300, and the optical module 400 is detachably supported by the attachment part 320 of the frame 300.

Figure 5a shows a plan view of the photocatalyst deodorizer corrugated sheet designed in the second embodiment of the present invention. The difference from the first embodiment is that two types of ventilation holes are perforated in the ridge 104 of the pleated sheet, and one is formed at a position corresponding to the LED array 410b of the optical module, so that light passes through the pleated sheet. It is designed to investigate behind the scenes. Figure 5b is a longitudinal cross-sectional view of a photocatalyst deodorizer combined with an optical module and schematically shows the relative positions of a plurality of ventilation holes and an LED array.

FIG. 6 is a plan view showing that the LED arrays 410a and 410b on the mesh screen of the optical module 400 are arranged corresponding to the valleys and peaks of the photocatalyst pleated sheet 100 in the second embodiment. In the case of the first embodiment, it is regarded as a simple mesh screen without the LED array 410b arranged on the floor 104, and the drawing is omitted.

As described above, in the detailed description of the present invention, preferred embodiments of the present invention have been described, but this is an illustrative description of the best embodiment of the present invention and does not limit the present invention. In addition, it goes without saying that anyone with ordinary knowledge in the technical field to which the present invention pertains can make various modifications and imitations without departing from the scope of the technical idea of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the claims described below as well as their equivalents.

100: Photocatalyst pleated sheet 102: Corrugation
104: Floor 110: Ventilation hole
200: Holder 300: Support frame
400: Optical module 410a: First LED array
410b: first LED array 320: detachable part
310: Fixing part

Claims (2)

It includes an optical module consisting of a wrinkled ACF-based photocatalyst sheet coated with a photocatalyst material, and a mesh screen disposed on one side of the photocatalyst sheet and having a plurality of LED arrays arranged therein. An activated carbon fiber-based photocatalytic deodorizer, wherein ventilation holes are punched, and the plurality of LED arrays are arranged to irradiate toward the valleys of the corrugated sheet. It includes an optical module consisting of a wrinkled ACF-based photocatalyst sheet coated with a photocatalyst material, a mesh screen disposed on one side of the photocatalyst sheet and a plurality of LED arrays arranged, and valleys and crests of the photocatalyst sheet viewed from the gas flow direction. A plurality of ventilation holes are punched in, a first array of the plurality of LED arrays is arranged to irradiate toward the valley of the corrugated sheet, and a second array is arranged to irradiate the back surface of the photocatalyst sheet through the ventilation holes formed in the floor. An activated carbon fiber-based photocatalytic deodorizer, characterized in that it is arranged to irradiate.

Images