WO2012077969A9

WO2012077969A9 - Photocatalytic reactor

Info

Publication number: WO2012077969A9
Application number: PCT/KR2011/009416
Authority: WO
Inventors: Jong-Heop Yi; Hyeong-Jin Yun; David Minzae Lee
Original assignee: Woongjincoway Co., Ltd.; Snu R&Db Foundation; Yun, Seong-Jin
Priority date: 2010-12-07
Filing date: 2011-12-07
Publication date: 2012-09-13
Also published as: WO2012077969A3; WO2012077969A2; KR20120063171A; JP2014500797A; JP5841164B2

Abstract

Provided is a photocatalytic reactor. The photocatalytic reactor includes an ultraviolet (UV) light source emitting UV rays and a felt disposed to surround a circumference of the UV light source, the felt being coated with a photocatalyst. A reaction passage is defined between the UV light source and the felt to purify a polluted fluid introduced therein through photocatalytic reaction.

Description

PHOTOCATALYTIC REACTOR

The present invention relates to a photocatalytic reactor, and more particularly, to a photocatalytic reactor which includes a light source for causing photocatalytic reaction and a photocatalytic reaction device reacting with the light source to realize sterilization, disinfection, and bad smell removal.

Photocatalysts are one kind of catalysts. The photocatalysts receive light energy to cause catalytic reaction. In general photocatalytic reactors which are configured to realize sterilization, disinfection, and bad smell removal, TiO₂ is being widely used as a photocatalyst and an ultraviolet (UV) light source is being widely used as a light source.

Light energy of the light source is transmitted into the photocatalyst to cause photocatalytic reaction, and thus oxides having a strong sterilizing power are generated to realize the sterilization, disinfection, and bad smell removal. Thus, water or air containing pollutants is injected in the state in which the photocatalytic reaction occurs within such a photocatalytic reactor to obtain the effects of the recirculation.

The photocatalytic reactor is disclosed in Korean Patent Registration No. 0463703 (hereinafter, referred to as a "related art"). The photocatalytic reactor according to the related art includes a riser tube 21 provided with a quartz tube and filled with a photocatalyst, a porous dispersion plate 23 disposed on a lower end of the riser tube 21, a reaction gas injection part 28 disposed on the lowermost end of the porous dispersion plate 23, a cyclone 26 connected to an upper portion of the riser tube 21, a down comer 25 disposed on a lower end of the cyclone 26, a recirculation equipment connected to the porous dispersion plate 23, disposed on an end of the down comer 25, and having a loop-seal shape, a reaction gas discharge part 27 disposed on the uppermost ends of the cyclone 26 and the riser tube 21, and a UV lamp 22 disposed outside the riser tube 21.

However, in the photocatalytic reactor according to the related art, since the photocatalyst is filled into the riser tube 21, an amount of photocatalyst required for the photocatalytic reactor increases when compared with the sterilization, disinfection, and bad smell removal performance. Also, since the photocatalyst is circulated together with the reaction gas, the sterilization, disinfection, and bad smell removal performance may be nonuniform.

Accordingly, the present invention is directed to a photocatalytic reactor that substantially obviates one or more problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a photocatalytic reactor having uniform sterilization, disinfection, and bad smell removal performance while the photocatalyst is fixed to the photocatalytic reactor to utilize a small amount of photocatalyst.

According to an aspect of the present invention, there is provided a photocatalytic reactor including: an ultraviolet (UV) light source emitting UV rays; and a felt disposed to surround a circumference of the UV light source, the felt being coated with a photocatalyst, wherein a reaction passage is defined between the UV light source and the felt to purify a polluted fluid introduced therein through photocatalytic reaction.

The UV light source may have a cylindrical shape, and the felt on which the photocatalyst is coated may be disposed on a cylindrical sheet outside the UV light source.

The photocatalytic reactor may further include: an upper housing on which the UV light source is disposed; and a lower housing on which the felt is disposed, the lower housing being coupled to the upper housing.

The upper housing and the lower housing may be closely attached by a contact unit.

An injection part through which the polluted reaction fluid is introduced through an injection hole may be disposed on the lower housing, the reaction passage may be defined between an outer wall of the upper housing and an inner wall of the lower housing, and a discharge hole through which the purified fluid is discharged may be defined in the upper housing.

The injection hole and the injection part may be disposed perpendicular to each other, and a path of the polluted reaction fluid introduced through the injection hole may be vertically bent at the injection part to cause a turbulence flow when the polluted reaction fluid is moved into the reaction passage.

The injection hole may be inclined downward from the injection part, and a path of the polluted reaction fluid introduced through the injection hole may be bent at the injection part to cause a turbulence flow when the polluted reaction fluid is moved into the reaction passage.

An injection direction of the injection hole may be spaced a predetermined distance from a center of the injection part, and the path of the polluted reaction fluid introduced through the injection hole may have a spiral shape within the injection part to cause the turbulence flow.

The injection hole may be disposed in each of both side surfaces of the injection part.

According to another aspect of the present invention, there is provided a photocatalytic reactor including: an ultraviolet (UV) light source emitting UV rays; and a felt disposed to surround a circumference of the UV light source, the felt being coated with a photocatalyst; a lower housing having an opening in an upper portion thereof and on which the felt coated with the photocatalyst is disposed on an inner wall thereof, the lower housing including an injection part through which a polluted reaction fluid is injected through an injection hole; and an upper housing inserted into the lower housing and in which a discharge hole for discharging a purified fluid through a discharge passage to the outside, the upper housing including a light source protection part on which the UV light source is disposed, wherein a reaction passage is defined between the UV light source and the felt to purify the polluted fluid introduced therein through photocatalytic reaction.

In the photocatalytic reactor according to the present invention, the photocatalyst may be coated and fixed between the organizations of the felt to obtain high photocatalytic reaction efficiency in the narrow space.

Also, since the injection hole has a shape suitable for causing the turbulence flow within the reaction passage, the reaction rate of the photocatalytic reaction may increase.

FIG. 1 is a partial sectional view illustrating a front surface of a photocatalytic reactor according to a first embodiment of the present invention.

FIG. 2 is a partial sectional view illustrating a side surface of the photocatalytic reactor according to the first embodiment of the present invention.

FIG. 3 is a partial sectional view illustrating a front surface of a lower housing of the photocatalytic reactor according to the first embodiment of the present invention.

FIG. 4 is a partial sectional view illustrating a side surface of the lower housing of the photocatalytic reactor according to the first embodiment of the present invention.

FIG. 5 is a sectional view illustrating the lower housing of the photocatalytic reactor according to the first embodiment of the present invention and a sectional view taken along line A-A of FIG. 3.

FIG. 6 is a partial sectional view illustrating a front surface of an upper housing of the photocatalytic reactor according to the first embodiment of the present invention.

FIG. 7 is a partial sectional view illustrating a side surface of the upper housing of the photocatalytic reactor according to the first embodiment of the present invention.

FIG. 8 is a front view illustrating a lower housing of a photocatalytic reactor according to a second embodiment of the present invention.

FIG. 9 is a side view illustrating the lower housing of the photocatalytic reactor according to the second embodiment of the present invention.

FIG. 10 is a sectional view illustrating the lower housing of the photocatalytic reactor according to the second embodiment of the present invention and a sectional view taken along line A-A of FIG. 8.

FIG. 11 is a front view illustrating a lower housing of a photocatalytic reactor according to a third embodiment of the present invention.

FIG. 12 is a side view illustrating the lower housing of the photocatalytic reactor according to the third embodiment of the present invention.

FIG. 13 is a sectional view illustrating the lower housing of the photocatalytic reactor according to the third embodiment of the present invention and a sectional view taken along line C-C of FIG. 11.

FIG. 14 is an enlarged photograph of a felt coated with photocatalyst of a photocatalytic reactor according to the present invention.

FIG. 15 is a comparison test graph illustrating reaction results depending on a reaction gas flow rate in the photocatalytic reactor according to the present invention.

FIG. 16 is a graph of results obtained by testing stability of the photocatalytic reactor according to the present invention.

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

Hereinafter, preferable embodiments of a photocatalytic reactor according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a partial sectional view illustrating a front surface of a photocatalytic reactor according to a first embodiment of the present invention. FIG. 2 is a partial sectional view illustrating a side surface of the photocatalytic reactor according to the first embodiment of the present invention.

Referring to FIGS. 1 and 2, a photocatalytic reactor according to the present invention includes an upper housing 30 and a lower housing 20.

Each of the upper housing 30 and the lower housing 20 may be formed of a glass material to penetrate light. Each of the upper and

lower housings

30 and 20 may have an approximately cylindrical shape on the whole. An upper portion of the lower housing 20 has a diameter greater than that of the upper housing 30. Thus, the upper housing 30 is inserted into the lower housing 20. A contact unit 5 is disposed on both side surfaces of the upper and

lower housings

30 and 20 to fix the upper and

lower housings

30 and 20 in the state where the upper housing 30 is inserted into the lower housing 20.

A reaction passage 10 is defined between an outer surface of the upper housing 30 and an inner surface of the lower housing 20. Here, photocatalytic reaction occurs within the reaction passage 10.

FIGS. 3 and 4 are partial sectional views illustrating the lower housing 20 of the photocatalytic reactor according to the first embodiment of the present invention. FIG. 3 illustrates a front view of the lower housing 20, and FIG. 4 illustrates a side view of the lower housing 20. FIG. 5 is a sectional view illustrating the lower housing 20 of the photocatalytic reactor according to the first embodiment of the present invention, and a sectional view taken along line A-A of FIG. 3.

Referring to FIGS. 3 and 5, a lower contact part 25 is disposed at an upper portion of the lower housing 20 of the photocatalytic reactor according to the present invention. The lower contact part 25 is a portion closely attached to the upper housing 30. The lower contact part 25 has a diameter gradually increasing toward an upper side. An insertion hole 27 is defined in an upper end of the lower contact part 25 to insert the upper housing 30 into the lower housing 20 therethrough.

A lower hook part 26 is disposed on both side surfaces of the lower housing 20 below the lower contact part 25. The lower hook part 26 protrudes outside the lower housing 20 so that a lower end of the contact unit 5 for fixing the upper and

lower housings

30 and 30 to each other is hooked on the lower hook part 26. Thus, the outer surface of the upper housing 30 and the inner surface of the lower housing 20 are closely attached to seal the passage therebetween.

A reaction part 23 is disposed below the lower hook part 26. The reaction part 23 has a cylindrical shape with an inner space. A polluted fluid reacts within the reaction part 23.

An injection part 21 is disposed below the reaction part 23. An injection hole 22 is defined in one side surface of the injection part 21. The injection part 21 has an approximately cylindrical shape with an inner space. Also, an injection hole 22 is defined in a side surface of the injection part 21. The injection hole 22 has a long tube shape and is integrated with the injection part 21. The polluted fluid may be introduced into the lower housing 20 through the injection hole 22. A recess part 24 is defined between the injection part 21 and the reaction part 23. The recess part 24 is defined along a circumference of a sidewall of the lower housing 20 so that the sidewall has an inwardly recessed shape.

A drain part 29 is disposed below the injection part 21, and a drain valve 28 is disposed on the drain part 29. The drain part 29 discharges water or other liquids generated by the reaction to the outside. Here, the water or liquids are temporarily stored in a lower portion of the injection part 21, and then the drain valve 28 is opened to discharge the water or liquids at the same time. The drain part 29 extends downward from the injection part 21 and is integrated with the injection part 21.

FIGS. 6 and 7 are partial sectional views illustrating the upper housing 30 of the photocatalytic reactor according to the first embodiment of the present invention. FIG. 6 illustrates a front view of the upper housing 30, and FIG. 7 illustrates a side view of the upper housing 30.

Referring to FIGS. 6 and 7, a light source protection part 31 is disposed at a lower portion of the photocatalytic reactor according to the present invention.

A lower portion of the light source protection part 31 is closed, and the light source protection has a cylindrical outer appearance. Also, the light source protection part 31 has a cylindrical inner space to install the light source therein. The light source protection part 31 may be formed of a glass or quartz material to penetrate UV rays.

An opening 37 through which an UV light source 1 is introduced into the light source protection part 31 is defined in an upper portion of the light source protection part 31. The opening 37 has a diameter gradually increasing toward an upper side. Thus, the UV light source 1 may be easily installed. An upper hook part 39 is disposed on a side surface of the upper portion of the light source protection part 31. An upper end of the contact unit 5 is hooked on the upper hook part 39 and a lower end of the contact unit 5 is hooked on the lower hook part 26 to closely attach the upper and

lower housings

30 and 20 to each other through a tension of the contact unit 5.

A skirt part 33 is disposed on the outside of the upper portion of the light source protection part 31. A discharge passage is defined within the skirt part 33 protruding from an outer surface of the light source protection part 31 to extend downward. The discharge passage 34 is defined between an inner surface of the skirt part 33 and the outer surface of the light source protection part 31. A discharge hole 35 is defined in the outside of one side surface of the skirt part 33 and connected to the discharge passage 34. Thus, a fluid introduced into the discharge passage 34 is discharged through the discharge hole 35.

Referring to FIGS. 1 and 7, in the photocatalytic reactor according to the present invention, the light source protection part 31 of the upper housing 27 is inserted into the insertion hole 27 of the lower housing 20. In this state, when the contact unit 5 is installed on the upper hook part 39 and the lower hook part 26, the upper and

lower housings

30 and 20 are closely attached to each other.

Also, referring to FIGS. 2 and 14, a support 7 and a felt 6 coated with the photocatalyst are disposed on an inner surface of the reaction part 23 of the lower housing 20. The felt 6 has a cylindrical shape. A spray-type photocatalyst is coated on the felt 6 to allow the photocatalyst to be uniformly distributed between organizations of the felt 6. The support 7 is formed of a metal material to firmly support the felt 6. The support 7 has a diameter slightly greater than that of the felt 6. The support 7 adheres to an outer surface of the felt 6.

The reaction passage 10 through which the fluid flows is defined between an inner surface of the reaction part 23 on which the felt 6 and the support 7 are disposed and the outer surface of the light source protection part 31. The reaction passage 10 communicates with the discharge passage 34 defined at an upper side thereof and communicates with the injection part 21 disposed at a lower side thereof. Thus, when the polluted reaction fluid is introduced into the injection part 21 through the injection hole 22, the reaction fluid passes through the reaction passage 10 and the discharge passage 34. Then, the reaction fluid may be discharged through the discharge hole 35 to the outside.

When the UV light source 1 is operated and the reaction fluid is injected through the injection hole 22 using air (containing moisture) containing polluted materials, the photocatalytic reaction occurs within the reaction passage 10 to realize sterilization, disinfection, and bad smell removal. Then, the purified air is discharged through the discharge hole 35.

Here, the injection part 21 and the reaction passage 10 are vertically disposed. On the other hand, the injection hole 22 is horizontally disposed. Thus, since the injection hole 22 is disposed perpendicular to the injection part 21 and the reaction passage 10, a turbulence flow occurs within the reaction fluid. In this state, the turbulence flow may be stronger while passing through the recess part 24. Also, since the reaction fluid passes through the surrounding of the felt 6, a laminar flow may be completely changed into the turbulence flow. The reaction fluid is sterilized and disinfected, and the bad smell of the reaction fluid is removed while passing through the reaction passage 10. Also, since the complete turbulence flow occurs within the reaction fluid inside the reaction passage 10, contact probability between the reaction material and the photocatalyst. Thus, the reaction with the photocatalyst coated on a surface of the felt 6 may be activated when compared to that of the laminar flow. Also, since the reaction passage 10 is defined in the narrow space between the light source protection part 31 and the reaction part 23, the reaction fluid may be permeated between fibers constituting the felt 6 to increase a contact area. Therefore, the performance of the reaction device may be improved.

FIG. 8 is a front view illustrating a lower housing 20 of a photocatalytic reactor according to a second embodiment of the present invention. FIG. 9 is a side view illustrating the lower housing 20 of the photocatalytic reactor according to the second embodiment of the present invention. FIG. 10 is a sectional view illustrating the lower housing 20 of the photocatalytic reactor according to the second embodiment of the present invention and a sectional view taken along line A-A of FIG. 8.

Referring to FIGS. 8 to 10, in the lower housing 20 of the photocatalytic reactor according to the second embodiment of the present invention, an injection hole 41 and an injection part 21 are not perpendicular to each other, unlike the first embodiment, but the injection part 41 is inclined downward. Also, a central axis of the injection hole 41 and a central axis of the injection part 21 are not perpendicular to each other, but are spaced from each other. Thus, a reaction fluid injected through the injection hole 41 forms a spiral path to flow upward. Since the reaction fluid flows upward, a rate of the reaction fluid introduced into the injection hole 41 and the reaction part 23 increases. Also, since the reaction fluid forms the spiral path, a pressure may be applied to a felt 6 disposed on the outside thereof due to a centrifugal force. Thus, a turbulence flow may easily occur. Therefore, efficiency of the photocatalytic reactor may be improved.

FIG. 11 is a front view illustrating a lower housing 20 of a photocatalytic reactor according to a third embodiment of the present invention. FIG. 12 is a side view illustrating the lower housing 20 of the photocatalytic reactor according to the third embodiment of the present invention. FIG. 13 is a sectional view illustrating the lower housing 20 of the photocatalytic reactor according to the third embodiment of the present invention and a sectional view taken along line C-C of FIG. 11.

Referring to FIGS. 11 and 13, in the lower housing 20 of the photocatalytic reactor according to the third embodiment of the present invention, two

injection holes

42 and 43 are defined in an injection part 21. The two

injection holes

42 and 43 are parallely defined opposite to each other. Here, central axes of the two

injection holes

42 and 43 are spaced from a central axis of the injection part 21. Also, the two

injection holes

42 and 43 are inclined downward from the injection part 21. Thus, when a reaction fluid is introduced into the injection part 21 through the two

injection holes

42 and 43, the reaction fluid is moved upward along the spiral path while being mixed within the injection part 21. In this process, a turbulence flow occurs within the reaction fluid to improve a reaction effect within a reaction passage 10.

According to the photocatalytic reactor of the present invention, a nonuniform photocatalyst (e.g., titanium dioxide (TiO₂)) is coated on a felt 6 and disposed inside the reaction passage 10. Then, a fluid flow is maximally induced toward an inner wall of a reaction part 23, and simultaneously, the turbulence flow occurs within the reaction fluid to improve efficiency of the photocatalyst oxide reaction with respect to reaction materials within the reaction fluid.

Also, since the felt 6 coated with the photocatalyst is disposed to surround the outside of a UV light source 1 having a cylindrical shape, the oxide reaction of the photocatalyst onto which the UV light source 1 is emitted may uniformly occur over the reaction part 23.

FIG. 15 is a comparison test graph illustrating reaction results depending on a reaction gas flow rate in the photocatalytic reactor according to the present invention. FIG. 16 is a graph of results obtained by testing stability of the photocatalytic reactor according to the present invention.

FIG. 15 is a graph illustrating a reaction rate (Y-axis) of a reaction material within a reaction fluid to a flow amount (X-axis) of the reaction fluid. In FIG. 15, a graph No. 1 corresponds to a case in which a photocatalyst is coated on a smooth support formed of a general metal material, but a felt 6. A graph No. 2 corresponds to a case in which the photocatalyst is coated on the felt 6. A graph No. 3 corresponds to a case in which the photocatalyst is coated on the felt 6, i.e., a case in which a photocatalytic reactor having an injection hole 41 defined in a tangential direction according to the second embodiment is applied.

As shown in FIG. 15, the more the flow amount increases, the more kinetic energy of the fluid increases. Thus, the turbulence flow may more easily occur. Also, the more the flow amount increases, the more the reactivity increases. However, in case where the flow amount significantly increases to get out of a predetermined range, the reactivity may decrease. This is done because contact possibility between the reaction fluid and the photocatalyst decreases due to the reduction of a time staying in the reaction part 23.

In the device to which the above-described test is applied, when a polluted fluid is injected at a flow amount of about 5 liters per minute, the reaction rate is maximized. On the other hand, when the polluted fluid is injected at a flow amount greater than that of about 5 liters per minute, the reaction rate is reduced.

Also, it may be confirmed that the reactivity is significantly improved in the graph No. 2 corresponding to the case in which the photocatalyst is coated on the felt 6 when compared to the graph No. 1 corresponding to the case in which the photocatalyst is coated on the general smooth metal. Also, it may be confirmed that the reactivity is significantly improved in the graph No. 3 corresponding to the case in which the injection hole 41 is defined in the tangential direction according to the second embodiment when compared to the graph No. 2 corresponding to the case in which the injection hole 22 is vertically defined according to the first embodiment.

FIG. 16 is a graph illustrating stability test results obtained by using the photocatalytic reactor according to the second embodiment. Referring to FIG. 16, it may be confirmed that the reaction rate is not reduced even though the photocatalytic reactor is continuously operated for several days. Since the photocatalyst is injected and coated onto the felt 6, the photocatalyst may be separated from the felt 6 when the photocatalytic reactor is used for a long time. However, since the reaction fluid is flows upward along the inner wall of the reaction part 23, it may be confirmed that the generated tension is relatively weak when compared to the force separating photocatalyst particles from the felt 6.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

A photocatalytic reactor comprising:

an ultraviolet (UV) light source emitting UV rays; and

a felt disposed to surround a circumference of the UV light source, the felt being coated with a photocatalyst,

wherein a reaction passage is defined between the UV light source and the felt to purify a polluted fluid introduced therein through photocatalytic reaction.
The photocatalytic reactor of claim 1, wherein the UV light source has a cylindrical shape, and

the felt on which the photocatalyst is coated is disposed on a cylindrical sheet outside the UV light source.
The photocatalytic reactor of claim 1, further comprising:

an upper housing on which the UV light source is disposed; and

a lower housing on which the felt is disposed, the lower housing being coupled to the upper housing.
The photocatalytic reactor of claim 3, wherein the upper housing and the lower housing are closely attached by a contact unit.
The photocatalytic reactor of claim 3, wherein an injection part through which the polluted reaction fluid is introduced through an injection hole is disposed on the lower housing,

the reaction passage is defined between an outer wall of the upper housing and an inner wall of the lower housing, and

a discharge hole through which the purified fluid is discharged is defined in the upper housing.
The photocatalytic reactor of claim 5, wherein the injection hole and the injection part are disposed perpendicular to each other, and a path of the polluted reaction fluid introduced through the injection hole is vertically bent at the injection part to cause a turbulence flow when the polluted reaction fluid is moved into the reaction passage.
The photocatalytic reactor of claim 5, wherein the injection hole is inclined downward from the injection part, and a path of the polluted reaction fluid introduced through the injection hole is bent at the injection part to cause a turbulence flow when the polluted reaction fluid is moved into the reaction passage.
The photocatalytic reactor of claim 7, wherein an injection direction of the injection hole is spaced a predetermined distance from a center of the injection part, and the path of the polluted reaction fluid introduced through the injection hole has a spiral shape within the injection part to cause the turbulence flow.
The photocatalytic reactor of claim 5, wherein the injection hole is disposed in each of both side surfaces of the injection part.
A photocatalytic reactor comprising:

an ultraviolet (UV) light source emitting UV rays; and

a felt disposed to surround a circumference of the UV light source, the felt being coated with a photocatalyst;

a lower housing having an opening in an upper portion thereof and on which the felt coated with the photocatalyst is disposed on an inner wall thereof, the lower housing comprising an injection part through which a polluted reaction fluid is injected through an injection hole; and

an upper housing inserted into the lower housing and in which a discharge hole for discharging a purified fluid through a discharge passage to the outside, the upper housing comprising a light source protection part on which the UV light source is disposed,

wherein a reaction passage is defined between the outer wall of upper housing and the felt disposed on the lower housing to purify the polluted fluid introduced therein through photocatalytic reaction.