KR20210048389A - Manufacturing method of photocatalyst bead and photocatalyst including photocatalyst bead - Google Patents

Abstract

Disclosed are a manufacturing method of photocatalyst beads and a photocatalyst filter including the photocatalyst beads. Specifically, the method for manufacturing the photocatalyst beads according to the present disclosure comprises the following steps of: preparing a titanium dioxide (TiO_2) powder and water in a drum included in a granulator for manufacturing the photocatalytic beads; rotating an impeller included in the granulator in a first direction to stir a titanium dioxide powder and water; and rotating the drum included in the granulator in a second direction opposite to the first direction to form a plurality of photocatalytic beads in which the titanium dioxide powder is granulated while the titanium dioxide powder and water are stirred. It is an object of the present disclosure to provide the photocatalyst beads with high purity and high performance having various sizes, and the method for efficiently manufacturing the photocatalyst filter including the photocatalyst beads.

Description

TECHNICAL FIELD The manufacturing method of a photocatalytic bead and a photocatalyst filter including the photocatalyst bead TECHNICAL FIELD OF THE INVENTION

The present disclosure relates to a photocatalytic bead manufacturing method and a photocatalytic filter including the photocatalytic beads, and specifically, by rotating an impeller and a drum included in a granulator in opposite directions to each other, a stirring process and a granulation process are simultaneously performed to include titanium dioxide. It relates to a method of manufacturing a photocatalytic bead, and a photocatalytic filter including the photocatalytic bead manufactured by the manufacturing method.

Recently, in the technical field of filters for air purifiers, research on photocatalytic filters continues as an alternative to solve problems such as short lifespan and bacterial growth of adsorption filters such as conventional activated carbon filters.

In particular, in recent years, a technology for manufacturing a photocatalytic filter has been developed by coating a photocatalytic material on the surface of a porous body of a filter or by forming a porous body using the photocatalyst material itself. In the case of manufacturing a photocatalytic filter, the toxic gas removal performance or mechanical stability did not meet the requirements of the industry.

Therefore, research on a technology for manufacturing a photocatalytic filter by using a method of making a photocatalytic material itself beaded continues, but according to the prior art, a high-temperature sintering process or addition of a binder is required in the manufacturing process of the photocatalytic bead. Therefore, there is a limit to manufacturing high purity and high performance photocatalytic beads. In addition, according to the prior art, it is a reality that it is difficult to efficiently manufacture photocatalytic beads of various sizes.

The present disclosure was devised to overcome the problems of the prior art as described above, and an object of the present disclosure is to provide a method for efficiently manufacturing a photocatalytic filter including photocatalytic beads of high purity and high performance having various sizes, and photocatalytic beads. It is in the offering.

According to an embodiment of the present disclosure for achieving the object of the present disclosure as described above, a method of manufacturing a photocatalytic bead includes titanium dioxide (TiO) in a drum included in a granulator for manufacturing the photocatalytic bead. ₂ ) preparing powder and water, rotating the impeller included in the granulator in a first direction to stir the titanium dioxide powder and the water, and while stirring the titanium dioxide powder and the water, the drum And forming a plurality of photocatalytic beads in which the titanium dioxide powder is granulated by rotating in a second direction opposite to the first direction.

Here, the plurality of photocatalytic beads may include photocatalytic beads composed of titanium dioxide having an anatase crystal structure.

Meanwhile, the plurality of photocatalytic beads may include photocatalytic beads having a diameter of 1 mm or more.

Meanwhile, the plurality of photocatalytic beads may be prepared without the addition of a binder for granulating the titanium dioxide powder.

Meanwhile, the plurality of photocatalytic beads may be manufactured without a sintering process at a temperature of 1000 degrees Celsius or higher.

On the other hand, the method of manufacturing the photocatalytic beads may further include classifying the formed photocatalytic beads according to size and drying the classified photocatalytic beads.

Meanwhile, the drum and the impeller may rotate in the first direction and the second direction with respect to the same rotation axis, and the rotation axis may achieve an angle of 30 degrees or more with respect to the ground.

Meanwhile, the impeller may include a plurality of blades, and one side surface of the plurality of blades may form an angle of less than 60 degrees with respect to a lower surface of the plurality of blades.

According to an embodiment of the present disclosure for achieving the object of the present disclosure as described above, a photocatalytic filter includes a frame and a plurality of photocatalytic beads coupled to the frame. In addition, the plurality of photocatalytic beads may include photocatalytic beads composed of titanium dioxide having an anatase crystal structure.

Here, while the plurality of photocatalytic beads stir the titanium dioxide powder and water as the impeller included in the granulator for producing the photocatalytic beads rotates in the first direction, the drum included in the granulator moves in the first direction and As the titanium dioxide powder is rotated in the second direction, which is the opposite direction, the titanium dioxide powder may be granulated to be formed.

Meanwhile, the plurality of photocatalytic beads may include photocatalytic beads having a diameter of 1 mm or more.

Meanwhile, some of the plurality of photocatalytic beads may be photocatalytic beads subjected to acid treatment or heat treatment at a temperature of 200°C to 600°C.

Meanwhile, the plurality of photocatalytic beads may be prepared without the addition of a binder for granulating the titanium dioxide powder.

On the other hand, the plurality of photocatalytic beads may be prepared without sintering at a temperature of 1000 degrees Celsius or higher.

Meanwhile, each of the plurality of photocatalytic beads may include the titanium dioxide and an adsorption material, and the weight% of the adsorption material in each of the plurality of photocatalytic beads may be less than 50.

Here, the weight% of the adsorption material may be 2 to 30.

Meanwhile, the plurality of photocatalytic beads are drum included in the granulator while stirring the titanium dioxide powder, the adsorbent material powder and water as the impeller included in the granulator for manufacturing the plurality of photocatalytic beads rotates in the first direction. The titanium dioxide powder and the adsorption material powder may be granulated and formed as the titanium dioxide powder and the adsorbent material powder rotate in a second direction opposite the first direction.

On the other hand, the adsorbent material may include at least one of zeolite (zeolite), sepiolite (sepiolite) and the mesoporous silica (mesoporous SiO _2).

Here, the zeolite may be one of natural zeolite and synthetic zeolite.

Here, the synthetic zeolite may be one of A zeolite, X zeolite, Y zeolite, ZSM-5 (Zeolite Socony Mobil number 5) zeolite, and beta zeolite.

Meanwhile, the adsorption material may be contained in a predetermined range in the plurality of photocatalytic beads.

1A is a flowchart briefly showing the overall flow of a method for manufacturing a photocatalytic bead according to an embodiment of the present disclosure;
1B is a flow chart showing in more detail the preparation process, the stirring process, and the granulation process of FIG. 1;
2A is a view for explaining the configuration of a granulator for manufacturing a photocatalytic bead according to the present disclosure;
2B is a view for explaining in more detail the impeller included in the granulator 100,
3A to 3D are views for explaining the anatase crystal structure of titanium dioxide constituting the photocatalytic bead according to the present disclosure and properties thereof, and the like;
4 is a block diagram schematically showing the constituent elements of a photocatalytic filter according to the present disclosure;
5A and 5B are views for explaining an embodiment related to a case where the photocatalytic filter according to the present disclosure includes a plurality of photocatalytic beads having different reactivity;
6 is a view for explaining an embodiment in which the photocatalytic bead includes an adsorbing material according to the present disclosure, and,
7A and 7B are graphs showing results of a harmful gas decomposition experiment according to the Clean Air (CA) standard test method by applying a photocatalytic filter according to various embodiments of the present disclosure to an air purifier.

Since the present exemplary embodiments may apply various transformations and may have various exemplary embodiments, specific exemplary embodiments will be illustrated in the drawings and will be described in detail in the detailed description. However, this is not intended to limit the scope of the specific embodiment, and it should be understood to include various modifications, equivalents, and/or alternatives of the embodiments of the present disclosure. In connection with the description of the drawings, similar reference numerals may be used for similar elements.

In describing the present disclosure, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present disclosure, a detailed description thereof will be omitted.

In addition, the following embodiments may be modified in various other forms, and the scope of the technical idea of the present disclosure is not limited to the following embodiments. Rather, these embodiments are provided to make the present disclosure more faithful and complete, and to completely convey the technical idea of the present disclosure to those skilled in the art.

The terms used in the present disclosure are only used to describe specific embodiments, and are not intended to limit the scope of the rights. Singular expressions include plural expressions unless the context clearly indicates otherwise.

In the present disclosure, expressions such as "have," "may have," "include," or "may include" are the presence of corresponding features (eg, elements such as numbers, functions, actions, or parts). And does not exclude the presence of additional features.

In the present disclosure, expressions such as "A or B," "at least one of A or/and B," or "one or more of A or/and B" may include all possible combinations of items listed together. . For example, "A or B," "at least one of A and B," or "at least one of A or B" includes (1) at least one A, (2) at least one B, Or (3) it may refer to all cases including both at least one A and at least one B.

Meanwhile, various elements and areas in the drawings are schematically drawn. Accordingly, the technical idea of the present invention is not limited by the relative size or spacing drawn in the accompanying drawings.

Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the embodiments.

1A is a flowchart briefly showing the overall flow of a method for manufacturing a photocatalytic bead according to an embodiment of the present disclosure, and FIG. 1B is a flowchart illustrating in more detail the preparation process, stirring process, and granulation process of FIG. 1.

A photocatalyst refers to a substance that affects the speed of a chemical reaction using light as an energy source, and in particular, it generally plays the role of a positive catalyst to increase the speed of a chemical reaction. In addition, the photocatalyst may be composed of titanium dioxide (TiO ₂ ), zinc oxide (ZnO), cadmium sulfide (CdS), and zirconium dioxide (ZrO ₂ ). Meanwhile, a photocatalyst bead refers to a photocatalyst implemented in a bead form.

A photocatalytic reaction is a chemical reaction promoted by a photocatalyst, and refers to a reaction that decomposes a substance adsorbed on the surface of the photocatalyst by the strong oxidizing power of radicals generated on the surface of the photocatalyst irradiated with ultraviolet rays. Specifically, when light energy more than the band gap energy is irradiated to the photocatalyst, the photon excites electrons from the valence band to the conduction band and creates a positive hole in the valence band. Leave. In addition, the holes in the valence band and electrons in the conduction band are oxidized and reduced on the surface of the photocatalyst to decompose a substance adsorbed on the photocatalyst into carbon dioxide or water that is harmless to the human body. For example, in the case of a photocatalytic bead composed of titanium dioxide, photocatalytic activity appears in the ultraviolet region with a wavelength of 400 nm or less.

As shown in FIG. 1A, a method of manufacturing a photocatalytic bead according to the present disclosure _{may be initiated by preparing titanium dioxide (TiO 2} ) powder and water (S110). Specifically, titanium dioxide powder and water may be prepared in a drum of a granulator for manufacturing a photocatalytic bead according to the present disclosure (S111). As described above, the photocatalyst may be composed of various materials, but in describing the present disclosure, a photocatalyst bead composed of titanium dioxide will be described.

When the titanium dioxide powder and water are prepared, the titanium dioxide powder and water may be agitation, and the titanium dioxide powder may be granulated (S120). In addition, by granulating the titanium dioxide powder, the titanium dioxide powder may be formed into a plurality of photocatalytic beads. In describing the present disclosure, the term'formation of photocatalytic beads' means that titanium dioxide powder is granulated to form titanium dioxide in the form of beads, and'photocatalytic beads are produced' as the drying process described below is completed. It is used in a different sense from being.

Specifically, as shown in FIG. 1B, the stirring process of the titanium dioxide powder and water according to the present disclosure may be performed by rotating the impeller included in the granulator in the first direction (S121). That is, the stirring process refers to a process of making a mixture of titanium dioxide powder and water in a homogeneous semi-dry state by kinetic energy generated as the impeller rotates in the first direction according to the present disclosure.

Meanwhile, the granulation process of the titanium dioxide powder according to the present disclosure may be performed by rotating the drum included in the granulator in a second direction opposite to the first direction while stirring the titanium dioxide powder and water (S122). . That is, the stirring and granulating processes according to the present disclosure are not separately performed through a stirrer and a granulator, respectively, but may be performed together in a granulator for manufacturing a photocatalytic bead.

Specifically, the granulation process may be performed as the dream included in the granulator rotates in a second direction opposite to the first direction while the impeller included in the granulator according to the present disclosure rotates in the first direction. For example, the rotation in the first direction may be that the impeller included in the granulator rotates in a clockwise direction, and the rotation in the second direction may be that the dream included in the granulator rotates in the counterclockwise direction. The configuration included in the granulator according to the present disclosure will be described in detail with reference to FIGS. 2A and 2B.

Meanwhile, the granulation process as described above may be performed without adding a seed and a binder for granulating the titanium dioxide powder. In addition, the photocatalytic beads according to the present disclosure may be manufactured in various sizes. This will be described in detail below by comparing the manufacturing method according to the present disclosure with the manufacturing method according to the prior art.

First, according to the prior art for producing a photocatalytic bead through rotation of the granulator, the stirring and granulation processes were performed separately through a granulator that does not include a stirrer and an impeller, respectively. Specifically, according to the prior art, the granulation process is performed by adding titanium dioxide powder and a binder that can serve as an adhesive to a stirrer and stirring, and adding a stirrer, water, and seeds to a separate granulator to rotate the granulator. Could. In other words, in the case of the prior art, there is a problem that it is difficult to perform without the addition of a seed and a binder for granulation. In addition, since the stirring process is not performed during the granulation process, the titanium dioxide powder is not uniformly mixed during the granulation process, and accordingly, the shape of the bead is not maintained after the granulation is performed to a size having a diameter of about 1 mm. There was this.

On the other hand, as described above, the stirring and granulating processes according to the present disclosure are not separately performed through a stirrer and a granulator, respectively, but may be performed together in a granulator. Specifically, according to the manufacturing method of the present disclosure, particles capable of serving as seeds may be generated in the titanium dioxide powder itself during the collision process with the impeller in the granulator. And, as the drum included in the granulator rotates in a second direction opposite to the first direction while the impeller included in the granulator rotates in the first direction, granulation proceeds around the particles that can serve as seeds. Photocatalytic beads can be formed. Furthermore, since the titanium dioxide powder is continuously and uniformly mixed while the stirring process is performed at the same time while the granulation process is performed, the granulation process is continuously performed to form photocatalytic beads of various sizes.

As described above, according to the manufacturing method of the present disclosure, binder-free high-purity photocatalytic beads can be prepared without the addition of seeds for granulation, and various diameters of about 0.5mm to 5mm Photocatalytic beads of a size, in particular, photocatalytic beads having a diameter of 1 mm or more can be prepared.

Meanwhile, as described above, the agitation process is simultaneously performed while the granulation process is performed, and the granulation and the impeller rotate in opposite directions to each other during the stirring and granulation process, so that granulation can be continuously performed, according to the manufacturing method of the present disclosure. Photocatalytic beads of sufficient hardness can be formed. In particular, the photocatalytic beads according to the present disclosure can be prepared without an additional high-temperature sintering process at a temperature of 1000 degrees Celsius or higher. Accordingly, the photocatalytic bead according to the present disclosure may be composed of titanium dioxide having an anatase crystal structure, thereby exhibiting excellent photocatalytic activity. The anatase crystal structure and properties thereof will be described in detail with reference to FIGS. 3A to 3D.

On the other hand, when the titanium dioxide powder is granulated to form a plurality of photocatalytic beads, the plurality of photocatalytic beads may be classified (S130). Specifically, as described above, according to the manufacturing method of the present disclosure, photocatalytic beads of various sizes may be manufactured, and when a plurality of photocatalytic beads are formed, the formed photocatalytic beads may be classified according to size. For example, a plurality of photocatalytic beads can be classified into those having a size of 0.5 mm or more and less than 1.0 mm, 1.0 mm or more and less than 2.0 mm, 2.0 mm or more and less than 4.0 mm, and 4.0 mm or more and less than 5.0 mm.

Meanwhile, when a plurality of photocatalytic beads are classified, the plurality of photocatalytic beads may be dried (S140). Although there are no particular restrictions on the conditions for drying the plurality of photocatalytic beads, as described later, titanium dioxide does not cause a phase transition from anatase to rutile or unintentionally decrease the reactivity of the photocatalytic beads to acid gases. , It may be desirable to dry below 150 degrees Celsius.

Meanwhile, in FIG. 1, a process of classifying a plurality of photocatalyst beads is performed, and then a process of drying a plurality of photocatalyst beads is performed. However, this is only for clearly showing an embodiment according to the present disclosure. There is no time-series order in the process of classifying and drying the photocatalytic beads of. That is, after drying a plurality of photocatalytic beads, it is possible to classify the dried photocatalytic beads, and it is also possible to pre-dry the plurality of photocatalytic beads, classify them, and then post-dry them again.

According to the manufacturing method of the present disclosure as described above, it is possible to efficiently manufacture high-purity and high-performance photocatalytic beads having various sizes.

2A is a view for explaining the configuration of a granulator 100 for manufacturing a photocatalytic bead according to the present disclosure, and FIG. 2B is a view for explaining in more detail the impeller 110 included in the granulator 100 to be.

2A, the granulator 100 according to the present disclosure may include an impeller 110 and a drum 120.

The impeller 110 may include a rotating shaft 121 and a plurality of blades 122 and 123. Although only a part of the rotation shaft 121 is shown in FIG. 2B, the rotation shaft 121 may extend to one side and be connected to a first motor (not shown). In addition, the rotation shaft 121 of the impeller 110 may be disposed to achieve an angle (a) of 30 degrees or more with respect to the ground as shown in FIG. 2A. Meanwhile, as shown in FIG. 2B, one side surface of some of the plurality of blades 123 may be implemented in a form that forms an angle b of less than 60 degrees with respect to the lower surface of the blade. In addition, as shown in FIG. 2B, some of the plurality of blades 122 may be disposed to form an angle of 90 degrees with respect to the other part 123 and the rotation shaft 121. Here, the angle (a) of the rotation shaft 121, the angle (b) of one side of the plurality of blades 123, the number of blades, and the angle between the plurality of blades 122, 123 according to the present disclosure In order to efficiently perform the stirring and granulation process, it may be selected in various ways, and is not limited to the above-described examples.

Meanwhile, the impeller 110 may agitate the titanium dioxide powder and water according to the present disclosure. Specifically, the impeller 110 may be disposed inside the drum 120 as shown in FIG. 2A and connected to a first motor (not shown) through the rotation shaft 121. When the first motor (not shown) is rotated, kinetic energy according to the rotation of the first motor (not shown) is transmitted to the impeller 110 through the rotation shaft 121, and accordingly, the impeller 110 is in the first direction ( 11) can be rotated. When the impeller 110 is rotated in the first direction 11, the titanium dioxide powder and water prepared in the drum 120 may be uniformly mixed and become a semi-dried mixture.

The drum 120 accommodates titanium dioxide powder and water according to the present disclosure. That is, the drum 120 serves as a space in which the stirring and granulation processes according to the present disclosure are performed. In addition, the drum 120 may granulate titanium dioxide powder. Specifically, the drum 120 may be connected to a second motor (not shown) and rotated by driving a second motor (not shown). When the drum 120 is rotated in the second direction 12, the semi-dried mixture formed by stirring of titanium dioxide and water is granulated based on the kinetic energy of the rotation of the drum 120 into a plurality of photocatalytic beads. Can be formed. Meanwhile, the rotation shaft (not shown) of the drum 120 may be located on the same line as the rotation shaft 121 of the impeller 110.

In particular, as described above, the stirring and granulation process according to the present disclosure may be performed together in the granulator 100.

Specifically, according to the manufacturing method of the present disclosure, particles capable of serving as seeds may be generated in the titanium dioxide powder itself during a collision process with the impeller 110 in the granulator 100. In addition, while the impeller 110 included in the granulator 100 rotates in the first direction 11, the drum 120 included in the granulator 100 rotates in the second direction opposite to the first direction 11. As it rotates in the direction 12, granulation proceeds around particles that can serve as seeds, so that photocatalytic beads may be formed. Furthermore, since the titanium dioxide powder is continuously and uniformly mixed while the stirring process is performed at the same time while the granulation process is performed, the granulation process is continuously performed to form photocatalytic beads of various sizes.

3A to 3D are views for explaining the anatase crystal structure of titanium dioxide constituting the photocatalytic bead according to the present disclosure and properties thereof.

3A is a diagram showing a phase diagram of titanium dioxide. That is, as shown in FIG. 3A, titanium dioxide may exist in different crystal structures such as anatase, rutile, and srilankite according to temperature and atmospheric pressure conditions. In particular, referring to FIG. 3A, when the temperature is increased to about 550 degrees Celsius or more under an atmospheric pressure of about 1 GPa, titanium dioxide may cause a phase transition from anatase to rutile.

Meanwhile, crystal structures of anatase and rutile are shown in FIGS. 3B and 3C, respectively. According to the difference in crystal structure as shown in FIGS. 3B and 3C, anatase and rutile have different physical properties. Specifically, anatase and rutile have different specific gravity, refractive index, hardness, melting point, and band gap energy according to the difference in crystal structure.

In particular, anatase exhibits higher photocatalytic activity than rutile, and therefore, when titanium dioxide on anatase is used as a material of the photocatalyst bead, it exhibits much better performance than when titanium dioxide on rutile is used.

Specifically, when anatase phase transitions to rutile, the specific surface area does not decrease due to particle coarsening at high temperature, so it has a relatively high specific surface area compared to the rutile phase, and thus has more active sites, so photocatalytic reactivity. This is better. In addition, the fact that the conduction band of anatase is at a more negative position than that of rutile, and that the degree of adsorption of hydroxyl groups or oxygen to the surface due to the crystal structure of anatase is higher can also contribute to the high photocatalytic activity of anatase.

3D shows an X-ray diffraction (XRD) graph of a photocatalytic bead prepared by the manufacturing method according to the present disclosure. As shown in Figure 3d, in the case of the photocatalytic bead according to the present disclosure, it can be seen that the main peaks of the XRD graph coincide with the main peaks of the anatase (see JCPDS card no.00-021-1272). And, the point that this result is derived from the point that the high-temperature sintering process at a temperature of 1000 degrees Celsius or higher is not required in the manufacturing method according to the present disclosure has been described above with reference to FIGS. 1A and 1B.

In other words, since the photocatalytic bead according to the present disclosure can be prepared without an additional high-temperature sintering process at a temperature of 1000 degrees Celsius or higher, it can exist in an anatase crystal structure without causing a phase transition to rutile, thereby exhibiting excellent photocatalytic activity. .

4 is a block diagram schematically showing the components of the photocatalytic filter 200 according to the present disclosure.

The photocatalytic filter 200 refers to a filter capable of removing harmful gases in the air through a photocatalytic reaction. In addition, as shown in FIG. 4, the photocatalytic filter 200 according to the present disclosure may include a filter frame 210 and a plurality of photocatalytic beads 220.

The filter frame 210 determines the size and shape of the photocatalytic filter 200 and supports a plurality of photocatalytic beads 220. Specifically, the filter frame 210 may be a breathable filter frame 210 that allows the photocatalytic filter 200 to pass air. For example, the filter frame 210 may be implemented in the form of a mesh including a mesh having a predetermined size, and in this case, the size of the mesh may have a size such that the photocatalytic beads 220 cannot pass. have. Meanwhile, the filter frame 210 may be made of a metal material such as stainless steel. However, there is no particular limitation on the material, size, and shape of the filter frame 210 according to the present disclosure.

The plurality of photocatalytic beads 220 refers to a photocatalyst implemented in the form of beads as described above. The plurality of photocatalytic beads 220 may be disposed on the filter frame 210 at predetermined intervals and numbers, and there is no particular limitation on the intervals and numbers. In particular, the plurality of photocatalytic beads 220 may be manufactured by the manufacturing method as described above with reference to FIGS. 1A to 3D.

Specifically, the plurality of photocatalytic beads 220 are, while stirring the titanium dioxide powder and water as the impeller included in the granulator for producing the photocatalytic beads rotates in the first direction, the drum included in the granulator is in the first direction and It may be formed while being granulated as it rotates in the second direction, which is the opposite direction. In addition, the plurality of photocatalytic beads 220 may include a photocatalytic bead 220 composed of titanium dioxide having an anatase crystal structure, thereby exhibiting excellent photocatalytic activity.

Meanwhile, the plurality of photocatalytic beads 220 may include photocatalytic beads 220 of various sizes. That is, according to the manufacturing method of the present disclosure as described above, photocatalytic beads 220 of various sizes having a diameter of about 0.5 mm to 5 mm may be manufactured, and in particular, photocatalytic beads 220 having a diameter of 1 mm or more may be included. I can. In addition, the photocatalytic filter 200 according to the present disclosure may include photocatalytic beads 220 of various sizes manufactured according to the manufacturing method of the present disclosure.

On the other hand, some of the plurality of photocatalytic beads 220 may be post-treated to have different reactivity with other parts, and thus may be included in the photocatalytic filter 200 together with the photocatalytic beads 220 that are not post-treated. It will be described in detail with reference to 5a and 5b.

Meanwhile, in the above, the photocatalytic filter 200 according to the present disclosure has been described as including only photocatalytic beads manufactured by the manufacturing method according to the present disclosure, but the present disclosure is not limited thereto. That is, the photocatalytic filter 200 may be implemented in a manner including all photocatalytic beads manufactured by a method different from the manufacturing method according to the present disclosure together with the photocatalytic beads manufactured by the manufacturing method according to the present disclosure.

Meanwhile, the photocatalytic filter 200 according to the present disclosure may be disposed inside the air purifier to decompose harmful gases sucked into the air purifier. Specifically, the air purifier includes a fan for inhaling air, a photocatalytic filter 200 for decomposing harmful gases contained in the air sucked through the fan, and a photocatalytic bead 220 included in the photocatalyst filter 200. A light emitting unit that irradiates ultraviolet rays to the photocatalytic bead 220 so as to perform a reaction, a memory including a command for controlling the air purifier, and a processor controlling the operation of the air purifier by executing a command stored in the memory. I can. Meanwhile, in addition to the photocatalytic filter 200 according to the present disclosure, the air purifier may further include various filters such as a pre-filter, a HEPA filter, a deodorizing filter, and a carbon dioxide adsorption filter, and the light emitting unit may include a plurality of LEDs.

The photocatalytic filter as described above may exhibit excellent toxic gas removal performance. A result of a noxious gas decomposition experiment according to various embodiments of the present disclosure will be described with reference to FIGS. 7A and 7B.

5A and 5B are views for explaining an embodiment related to a case where the photocatalytic filter 200 according to the present disclosure includes a plurality of photocatalytic beads 220 having different reactivity.

As described above with reference to FIG. 1B, according to the manufacturing method of the present disclosure, the stirring process is performed simultaneously with the granulation process, and the impeller and the drum included in the granulator during the stirring and granulation process rotate in opposite directions to each other, thus having sufficient hardness. A photocatalytic bead 220 may be formed. That is, the photocatalytic bead 220 according to the present disclosure may be manufactured without an additional high-temperature sintering process at a temperature of 1000 degrees Celsius or higher. Therefore, additional post-treatment can be easily performed on the photocatalytic bead 220 according to the present disclosure. In describing the present disclosure, the term post-treatment refers to a treatment performed to adjust the surface properties of the photocatalytic beads 220 after the photocatalytic beads 220 are manufactured according to the manufacturing method described with reference to FIGS. 1A to 3D. It is used to collectively refer to the process.

The photocatalytic bead 220 manufactured according to the manufacturing method of the present disclosure is composed of titanium dioxide having an anatase crystal structure and exhibits excellent photocatalytic activity, but the reaction to the basic gas may be relatively lower than the reactivity to the acid gas. Accordingly, acid treatment may be performed to reduce the pH of the surface of the photocatalytic bead 220, or heat treatment may be performed under a predetermined temperature. Here, the predetermined temperature is a temperature within a range that does not cause a phase transition from anatase to rutile while improving the reactivity of the photocatalyst beads 220 with respect to the basic gas, and may be determined within a range of 200 to 600 degrees Celsius, and preferably May be determined within a range of 300 degrees to 400 degrees Celsius.

Meanwhile, the photocatalytic filter 200 according to the present disclosure may include both the photocatalytic beads 220 on which the post-processing process as described above has been performed and the photocatalytic beads 220 to which the post-processing process has not been performed. Specifically, in the photocatalytic filter 200, the photocatalytic bead 220-1 having improved reactivity to the basic gas by performing the post-treatment process as described above and the photocatalytic bead (220-1) having improved reactivity to the basic gas and the reactivity to the acid gas are maintained high. All of the photocatalytic beads 220-2 may be included.

In particular, the photocatalytic filter 200 according to the present disclosure is a filter in which the photocatalytic beads 220-1 and the photocatalytic beads 220-2 are mixed in one filter frame 210 as shown in FIG. 5A. In addition, as shown in FIG. 5B, a photocatalytic bead 220-1 and a photocatalytic bead 220-2 are disposed in the plurality of filter frames 210-1 and 210-2, respectively, and a plurality of filter frames (210-1, 210-2) may be implemented as a filter arranged in series.

According to the photocatalytic filter 200 as described above with reference to FIGS. 5A and 5B above, it is possible to secure a high level of removal performance for both acidic gas and basic gas.

6 is a view for explaining an embodiment in which the photocatalytic bead includes an adsorbing material according to the present disclosure.

Referring to FIG. 6, each of the plurality of photocatalytic beads 600 according to an embodiment of the present disclosure may include titanium dioxide 610 and an adsorption material 620. That is, FIG. 6 shows the molecules of titanium dioxide 610 and molecules of the adsorption material 620 included in one of the photocatalytic beads 600, and a part 600' of the photocatalytic beads 600. Includes an enlarged drawing. Since the photocatalytic bead 220 including the titanium dioxide 610 has been described above with reference to FIGS. 1A to 5B, hereinafter, the photocatalytic bead 600 including the adsorption material 620 and the adsorption material 620 will be described in detail. do. Meanwhile, hereinafter, for convenience of explanation, the photocatalytic beads 220 including the titanium dioxide 610 and not including the adsorption material 620 are referred to as'first photocatalytic beads', and the titanium dioxide 610 and adsorption The so-called hybrid photocatalytic bead 600 including all of the material 620 is referred to as a'second photocatalytic bead'.

The adsorption material 620 may adsorb the noxious gas 630 so that the noxious gas 630 is easily decomposed. Specifically, when air containing the noxious gas 630 is sucked through the fan, the adsorption material 620 captures the noxious gas 630, and the captured noxious gas 630 is discretized adjacent to the adsorption material 620. It can be diffused in the titanium 610. When the harmful gas 630 diffuses from the adsorption material 620 to the titanium dioxide 610, the titanium dioxide 610 can decompose the harmful gas 630 through the photocatalytic reaction as described above in the description of FIG. 1A. have. That is, the adsorption material 620 included in the photocatalytic bead 600 captures the harmful gas 630 that is difficult to be adsorbed on the titanium dioxide 610 among various types of harmful gases 630 and diffuses into the titanium dioxide 610. By doing so, it can serve to increase the removal rate of the harmful gas 630.

The proportion of the adsorption material 620 in the overall composition of the photocatalytic bead 600 is the adsorption function of the harmful gas 630 of the adsorbent material 620 without weakening the decomposition function of the harmful gas 630 of the titanium dioxide 610 It can be determined within a range that can improve. Specifically, the weight% of the adsorbent material 620 in the photocatalytic bead 600 may be less than 50. For example, the weight% of the adsorbent material 620 in the photocatalytic bead 600 may be 2 to [20]30.

Meanwhile, the second photocatalytic bead 600 according to the present disclosure may be manufactured in the same manner as the method of manufacturing the first photocatalytic bead 220 as described above with reference to FIGS. 1A to 5B. Specifically, the second photocatalytic bead 600 may be initiated by preparing an adsorption material powder together with titanium dioxide powder and water. Here, the weight% of the titanium dioxide powder, the adsorbent material powder, and the adsorbent material powder in water may be 2 to 30.

Then, when the titanium dioxide powder, the adsorption material powder and water are prepared, the titanium dioxide powder, the adsorption material powder and water are stirred, and the titanium dioxide powder and the adsorption material powder may be granulated. Specifically, the second photocatalytic bead 600 is a drum included in the granulator while stirring the titanium dioxide powder, the adsorbent powder and water as the impeller included in the granulator for manufacturing the photocatalytic bead rotates in the first direction. It may be formed by granulating titanium dioxide powder and adsorbent powder as it rotates in a second direction opposite to the first direction. In addition, the method of manufacturing the first photocatalytic bead 220 as described above with reference to FIGS. 1A to 5B may be similarly applied to the method of manufacturing the second photocatalytic bead 600.

Meanwhile, the adsorption material 620 may include at least one of zeolite, sepiolite, and mesoporous silica. Here, the zeolite may be one of natural zeolite and synthetic zeolite. Here, the synthetic zeolite may be one of A zeolite, X zeolite, Y zeolite, ZSM-5 (Zeolite Socony Mobil number 5) zeolite, and beta zeolite. However, the material of the adsorption material 620 according to the present disclosure is not limited to a specific material such as the above-described example.

Meanwhile, the adsorption material 620 may be contained in a predetermined range within the plurality of photocatalytic beads. In addition, the adsorption material 620 may be disposed at intervals of a preset range as shown in FIG. 6 to facilitate the diffusion of the harmful gas 630 to the titanium dioxide 610. Here, the ratio of the preset range and the spacing of the preset range may be changed by adjusting the weight% of the adsorbent powder and/or various variables of the stirring and granulation process as described above with reference to FIGS. 2A and 2B. have.

The second photocatalytic bead 600 as described above with reference to FIG. 6 has a higher decomposition performance of the harmful gas 630 than the first photocatalytic bead 220. The result of the decomposition experiment of the harmful gas 630 according to the embodiment of FIG. 6 will be described with reference to FIG. 7B.

7A and 7B are graphs showing results of a harmful gas decomposition experiment according to the Clean Air (CA) standard test method by applying a photocatalytic filter according to various embodiments of the present disclosure to an air purifier.

First, FIG. 7A shows the results of a noxious gas decomposition experiment of a photocatalytic bead including titanium dioxide and not including an adsorbent material, that is, a photocatalytic filter including the first photocatalytic bead 220.

Under the experimental conditions as described above, as a result of measuring the removal rate of the photocatalytic filter including the first photocatalytic bead 220 for 5 kinds of harmful gases indoors, the removal rate of formaldehyde at the time 30 minutes elapsed after the start of the experiment Silver 94%, ammonia removal rate 80%, acetaldehyde removal rate 56%, acetic acid removal rate 95%, and toluene removal rate 38%. 73%.

The average removal rate of 73% according to the result of this experiment corresponds to a value exceeding 70%, which is the average removal rate normally required by the certification standard in the field of air purifiers. Therefore, the experimental result as shown in FIG. 7A is a photocatalyst according to the present disclosure. It can be said that it is evidence to prove the excellent decomposition performance of harmful gases of the filter.

Meanwhile, FIG. 7B shows the results of a noxious gas decomposition experiment of a photocatalytic bead including both titanium dioxide and an adsorbent material, that is, a photocatalytic filter including the second photocatalytic bead 600.

Under the above-described experimental conditions, as a result of measuring the removal rate of the photocatalytic filter including the second photocatalytic bead 600 for 5 kinds of harmful gases indoors, the removal rate of formaldehyde at the time 30 minutes elapsed after the start of the experiment Silver was 100%, ammonia removal rate was 88%, acetaldehyde removal rate was 64%, acetic acid removal rate was 100%, and toluene removal rate was 69%. 84%.

That is, the photocatalytic filter including the second photocatalytic bead 600 has an average removal rate significantly higher than the average removal rate of 70%, which is typically required in the certification standard for the air purifier field, and includes the first photocatalytic bead 220. It can be seen that it has an average removal rate higher than 73%, which is the average removal rate of the photocatalytic filter. In particular, it can be seen that the photocatalytic filter including the second photocatalytic bead 600 has a significantly higher removal rate for toluene than the photocatalytic filter including the first photocatalytic bead 220.

In the above, the results of the noxious gas decomposition experiment of the photocatalytic filter according to the present disclosure have been described with reference to FIGS. 7A and 7B, but this is only an exemplary description for explaining the performance of the photocatalytic filter according to the present disclosure in detail. That is, the effect of the photocatalytic filter according to the present disclosure is not limited to the experimental results as shown in FIGS. 7A and 7B, and the effect of the photocatalytic filter according to the present disclosure is easy from the standpoint of a person skilled in the art. It can be proved through a variety of experiments that can be performed efficiently.

According to various embodiments of the present disclosure as described above, it is possible to efficiently manufacture high-purity and high-performance photocatalytic beads having various sizes, and photocatalytic filters including photocatalytic beads.

Specifically, according to the manufacturing method of the present disclosure, binder-free and high-purity photocatalytic beads can be prepared without the addition of seeds for granulation, and photocatalytic beads of various sizes having a diameter of about 0.5 mm to 5 mm can be efficiently prepared. I can. In addition, the photocatalytic bead according to the present disclosure may be composed of titanium dioxide having an anatase crystal structure, thereby exhibiting excellent photocatalytic activity.

In addition, the photocatalytic filter including the photocatalytic beads according to the present disclosure has excellent toxic gas removal performance, and in particular, since the post-treatment for adjusting the surface properties of the photocatalytic beads after the production of the photocatalytic beads can be easily performed, the acid gas It is possible to ensure a high level of removal performance for both and basic gas.

Furthermore, when the photocatalytic bead according to the present disclosure contains an adsorbent, the adsorbent may capture harmful gas and diffuse it into titanium dioxide, thereby further improving the harmful gas decomposition performance of the photocatalytic bead.

In the above, preferred embodiments of the present disclosure have been illustrated and described, but the present disclosure is not limited to the specific embodiments described above, and is not departing from the gist of the present disclosure as claimed in the claims. Of course, various modifications may be made by those skilled in the art, and these modifications should not be understood individually from the technical idea or perspective of the present disclosure.

100: granulator 110: impeller
120: drum 200: photocatalytic filter
210: filter frame 220: a plurality of photocatalytic beads

Claims (21)

In the method for producing a photocatalytic bead,
_{Preparing titanium dioxide (TiO 2} ) powder and water in a drum included in a granulator for producing the photocatalytic beads;
Stirring the titanium dioxide powder and the water by rotating the impeller included in the granulator in a first direction; And
While stirring the titanium dioxide powder and the water, rotating the drum in a second direction opposite to the first direction to form a plurality of photocatalytic beads granulated with the titanium dioxide powder; Method for producing a photocatalytic bead comprising a.
The method of claim 1,
The plurality of photocatalytic beads,
A method of producing a photocatalytic bead comprising a photocatalytic bead composed of titanium dioxide having an anatase crystal structure.
The method of claim 1,
The plurality of photocatalytic beads are
A method for producing a photocatalytic bead comprising a photocatalytic bead having a diameter of 1 mm or more.
The method of claim 1,
The plurality of photocatalytic beads,
A method for producing a photocatalytic bead prepared without the addition of a binder for granulating the titanium dioxide powder.
The method of claim 1,
The plurality of photocatalytic beads,
A method for producing a photocatalytic bead manufactured without a sintering process at a temperature of 1000 degrees Celsius or higher.
The method of claim 1,
Classifying the formed photocatalytic beads according to their size; And
Drying the classified plurality of photocatalytic beads; Method for producing a photocatalytic bead further comprising a.
The method of claim 1,
The drum and the impeller rotate in the first direction and the second direction with respect to the same axis of rotation,
The rotation axis is a method of manufacturing a photocatalytic bead forming an angle of 30 degrees or more with respect to the ground.
The method of claim 1,
The impeller includes a plurality of blades,
A method of manufacturing a photocatalytic bead in which one side surface of the plurality of blades forms an angle of less than 60 degrees with respect to the lower surface of the plurality of blades.
In the photocatalytic filter,
frame; And
A plurality of photocatalytic beads coupled to the frame; Including,
Each of the plurality of photocatalytic beads,
A photocatalytic filter containing titanium dioxide having an anatase crystal structure.
The method of claim 9,
The plurality of photocatalytic beads,
As the impeller included in the granulator for manufacturing the plurality of photocatalytic beads rotates in the first direction, while stirring the titanium dioxide powder and water, the drum included in the granulator is in a second direction opposite to the first direction A photocatalytic filter formed by granulating the titanium dioxide powder as it rotates.
The method of claim 9,
The plurality of photocatalytic beads,
A photocatalytic filter comprising photocatalytic beads having a diameter of 1 mm or more.
The method of claim 9,
Some of the plurality of photocatalytic beads,
A photocatalytic filter, which is a photocatalytic bead subjected to acid treatment or heat treatment at a temperature of 200 degrees Celsius to 600 degrees Celsius.
The method of claim 9,
The plurality of photocatalytic beads,
A photocatalytic filter manufactured without the addition of a binder for granulating the titanium dioxide powder.
The method of claim 9,
The plurality of photocatalytic beads,
Photocatalytic filter manufactured without sintering at temperatures above 1000 degrees Celsius.
The method of claim 9,
Each of the plurality of photocatalytic beads,
Including the titanium dioxide and adsorption material,
A photocatalytic filter in which the weight% of the adsorbed material in each of the plurality of photocatalytic beads is less than 50.
The method of claim 15,
A photocatalytic filter in which the weight% of the adsorbed material is 2 to 30.
The method of claim 15,
The plurality of photocatalytic beads,
As the impeller included in the granulator for manufacturing the plurality of photocatalytic beads rotates in the first direction, while stirring the titanium dioxide powder, the adsorbent material powder, and water, the drum included in the granulator is in a direction opposite to the first direction. A photocatalytic filter formed by granulating the titanium dioxide powder and the adsorbent material powder as it rotates in the phosphorus second direction.
The method of claim 15,
The adsorbent material,
A photocatalytic filter comprising at least one of zeolite, sepiolite, and mesoporous silica.
The method of claim 18,
The zeolite,
A photocatalytic filter that is at least one of natural zeolite and synthetic zeolite.

The method of claim 19,
The synthetic zeolite is
A photocatalytic filter that is one of zeolite, X zeolite, Y zeolite, ZSM-5 (Zeolite Socony Mobil number 5) zeolite, and beta zeolite.

The method of claim 15,
The adsorbent material,
A photocatalytic filter contained in a ratio of a preset range in the plurality of photocatalytic beads.

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