JP2015182022A - Exhaust gas processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend the life of a filter, and to reduce a replacement cost.SOLUTION: An exhaust gas processing device 1 includes: a filter 41 provided on a gas channel 10, and performing the adsorption of organic matters and the decomposition of ozon gas; an ozon gas supplying portion 3 for supplying the ozone gas to the filter 41; and a gas switching portion for switching the introduction of exhaust gas including the organic matters and the introduction of outside air. The exhaust gas including the organic matters is introduced into the gas channel 10, and in the filter 41, the organic matters are adsorbed and the ozone gas supplied from the ozone gas supplying portion 3 is decomposed to generate active species. By using the active species, the decomposition of the adsorbed organic mattes is performed. On the other hand, the outside air is introduced into the gas channel 10, and by using the active species generated by the decomposition of the ozone gas supplied from the ozone gas supplying portion 3, the organic matters accumulated in the filter 41 is decomposed.

Description

  The present invention relates to an exhaust gas treatment apparatus that decomposes organic substances contained in exhaust gas.

  Gases emitted from commercial facilities, chemical factories, pharmaceutical factories, food factories, livestock facilities, etc. (hereinafter referred to as “exhaust gas”) may contain organic substances that cause foul odors. It is not preferable to discharge the exhaust gas containing organic substances to the outside as it is in view of the surrounding environment. Therefore, an exhaust gas treatment apparatus mainly using a filter has been used. A duct that serves as a gas flow path is provided on the ceiling, outer wall, basement, etc. of the facility, and a filter is installed in this duct. When the exhaust gas passes through the filter, organic substances contained in the exhaust gas are adsorbed by the filter, so that the organic substances can be removed from the exhaust gas and deodorized.

  The filter is made of activated carbon, zeolite, or the like, but when organic matter is accumulated in the filter, the adsorption performance of the filter gradually decreases. Eventually, the filter is in a state where it cannot adsorb organic matter any more, that is, a breakthrough state. Therefore, it is necessary to periodically replace the filter with a new one.

  Accordingly, an exhaust gas treatment apparatus using ozone gas has been devised instead of using a filter. This is an apparatus for supplying ozone gas to the gas flow path. Ozone gas decomposes when it comes into contact with the ozone decomposition catalyst, and organic species contained in the exhaust gas are decomposed by active species such as oxygen radicals and OH radicals generated by the decomposition. The exhaust gas treatment apparatus using ozone gas does not require the replacement cost of the filter, but it is necessary to supply high-concentration ozone gas in order to sufficiently decompose the organic matter. However, if ozone gas that has not reacted with the ozone decomposition catalyst is released to the outside air, it may adversely affect the surrounding environment.

  Therefore, an exhaust gas treatment apparatus using both a filter and ozone gas has been proposed (see, for example, Patent Document 1). This type of exhaust gas treatment apparatus uses a filter having both an organic matter adsorption function and an ozone decomposition function. The filter adsorbs organic substances in the exhaust gas, and gradually decomposes the adsorbed organic substances with low-concentration ozone gas. That is, recovery of the adsorption performance of the filter while deodorizing the exhaust gas is performed, thereby extending the life of the filter and reducing the replacement cost.

JP 2001-327585 A

  However, when exhaust gas containing a high concentration of organic matter is discharged for a long time, the amount of organic matter decomposed by ozone gas does not catch up with the amount of organic matter accumulated in the filter, and the filter breaks through earlier than planned for replacement. It can lead to a condition. In such a case, the exhaust gas containing organic matter continues to be released to the outside air until the filter is replaced, which may affect the reliability of the exhaust gas treatment device.

  For such a possibility, it is conceivable to increase the size of the filter and increase the decomposition processing capacity, but a large installation space is required. Further, when the filter is enlarged, low concentration ozone gas does not reach the back of the filter, and the adsorption performance of the filter may not be sufficiently recovered. In the end, it was difficult to reduce the replacement cost, not only to prevent the breakthrough of the filter by frequently replacing the filter.

  In view of the above-mentioned problems, the present invention is highly reliable and can maintain a long-lasting filter even when a low-concentration ozone gas is used by performing a concentration treatment on a filter in which organic substances are accumulated. It aims at providing the waste gas processing apparatus excellent in economical efficiency.

  In order to achieve the above object, an exhaust gas treatment apparatus according to the present invention includes a filter that is provided in a gas flow path and that adsorbs organic matter and decomposes ozone gas, an ozone gas supply unit that supplies ozone gas to the filter, and the gas A gas switching unit that switches between introduction of exhaust gas containing organic substances and introduction of outside air into the flow path, introduces the exhaust gas into the gas flow path, and adsorbs organic substances contained in the exhaust gas in the filter Decomposing ozone gas supplied from the ozone gas supply unit to generate active species, decomposing the adsorbed organic matter using the active species, introducing the outside air into a gas flow path, Is used to decompose the organic matter accumulated in the filter.

  As one aspect of the present invention, the gas switching unit may switch between introduction of the exhaust gas and introduction of the outside air based on an operation schedule of a facility provided with the gas flow path.

  As one aspect of the present invention, the gas switching unit includes an organic sensor that measures the amount of organic matter contained in the exhaust gas that has passed through the filter, and when the amount of organic matter measured by the organic sensor reaches a predetermined amount, It is preferable to switch from introduction of exhaust gas to introduction of the outside air.

  As one aspect of the present invention, the concentration of ozone gas supplied by the ozone gas supply unit is about 15 ppm, and the filter is arranged in two stages inside the filter tower, and one sheet has a thickness of about 20 cm. good.

  As one aspect of the present invention, the filter may include an adsorbent obtained by mixing finely divided or granular activated carbon with a mineral mainly composed of silica-alumina.

  As one aspect of the present invention, the filter may include an adsorbent in which alkali metal is supported on activated carbon.

  As an aspect of the present invention, the ozone gas supply unit may include a straight tube type UV lamp disposed substantially parallel to the gas flow path.

  As an aspect of the present invention, the ozone gas supply unit may include an ozone gas generator that generates ozone gas using oxygen gas or air.

  As one aspect of the present invention, hydrogen peroxide gas is supplied to the gas flow path by supplying hydrogen peroxide gas and decomposing organic substances contained in the exhaust gas using activated species generated by decomposition of the hydrogen peroxide gas. It is good to further provide a part.

  As one aspect of the present invention, the gas flow path is a plurality of gas flow paths, each of the gas flow paths is provided with the filter and the ozone gas supply unit, and the gas switching unit is When switching from introduction of exhaust gas to introduction of the outside air, introduction of the exhaust gas is preferably started in at least one of the other gas flow paths.

  According to the exhaust gas treatment apparatus of the present invention, the organic matter accumulated in the filter is intensively decomposed by switching the gas flowing in the gas flow path from the exhaust gas to the outside air at predetermined time intervals, thereby improving the adsorption performance of the filter. It can be recovered regularly. Thereby, even when low-concentration ozone gas is used, the filter can last longer, the replacement cost can be reduced, and the economy is excellent. Moreover, since the filter regeneration process can be switched by simply switching the gas flowing in the gas flow path, easy control is possible.

1 is a schematic configuration diagram of an exhaust gas treatment apparatus according to a first embodiment of the present invention. It is a figure which shows the structural example of an ozone gas supply part. It is a figure which shows another structural example of an ozone gas supply part. It is a figure which shows the structural example of a filter. It is a block diagram which shows the structural example of a gas switching part. It is a graph which shows the experimental result of the Example of this invention. It is a graph which shows the experimental result of a comparative example. It is a schematic block diagram of the waste gas processing apparatus which concerns on 2nd Embodiment of this invention. It is a block diagram which shows the structural example of the gas switching part of the exhaust gas processing apparatus which concerns on 2nd Embodiment of this invention. It is a schematic block diagram of the waste gas processing apparatus which concerns on 3rd Embodiment of this invention.

[First Embodiment]
An exhaust gas treatment apparatus according to a first embodiment of the present invention will be described with reference to FIG.
(Constitution)
The exhaust gas treatment apparatus 1 of the present embodiment removes organic substances contained in the gas discharged from the facility and deodorizes the exhaust gas. Depending on the facility, there are various organic substances contained in the exhaust gas. For example, in chemical factories, menthol-based organic substances, L-menthol, methyl salicylate, DL-camphor, etc. discharged in the manufacturing process are used as exhaust gas. included. In a factory having an adhesion process, an adhesive is dissolved in an organic solvent such as toluene or xylene and used. At that time, the volatilized organic solvent is contained in the exhaust gas.

  The exhaust gas treatment apparatus 1 is disposed in a gas flow path 10 that leads from the inside of the facility to the outside. The gas flow path 10 is a duct that is piped to, for example, the ceiling, outer wall, or underground of a facility. Here, in the gas flow path 10, the inside of the facility where the exhaust gas is introduced is referred to as “upstream side”, and the outside of the facility where the exhaust gas is discharged is referred to as “downstream side”. Further, in the description of the positional relationship between the respective components arranged in the gas flow path 10, when a certain configuration is located on the upstream side of another configuration, it is referred to as “front stage”, and when located on the downstream side, it is referred to as “rear stage”. .

  As shown in FIG. 1, on the upstream side of the gas flow path 10, a damper 11 that switches communication between the inside of the facility and the gas flow path 10 is provided. The opening and closing of the damper 11 switches the introduction and blocking of the exhaust gas inside the facility into the gas flow path 10.

  A damper 12 for introducing outside air into the gas flow path 10 is also provided on the upstream side of the gas flow path 10. Opening and closing of the outside air to the gas flow path 10 is switched by opening and closing the damper 12. An exhaust fan 13 is provided downstream of the dampers 11 and 12, and exhaust gas or outside air supplied to the gas passage 10 is caused to flow downstream of the gas passage 10. An exhaust hood or exhaust gallery 14 is provided at the end of the gas flow path 10, and exhaust gas or outside air supplied to the gas flow path 10 is exhausted to the outside air through this.

  The exhaust gas treatment device 1 is disposed between the dampers 11 and 12 and the exhaust hood or exhaust gallery 14. The exhaust gas treatment apparatus 1 includes a hydrogen peroxide supply unit 2, an ozone gas supply unit 3, and a filter tower 4 in order from the upstream side of the gas flow path 10.

  The exhaust gas treatment apparatus 1 also includes a control unit 7 that controls each unit. The control unit 7 is connected to each unit of the exhaust gas treatment apparatus 1 and controls its operation. The control unit 7 can be configured by a PLC (Programmable Logic Controller) that executes a program necessary for controlling each unit. Moreover, the control part 7 is connected to input parts, such as a mouse | mouth, a keyboard, and a touchscreen, and can be suitably controlled by a user's input.

  The control unit 7 switches the operation and stop of the hydrogen peroxide supply unit 2 and the ozone gas supply unit 3, and controls the supply amount of the hydrogen peroxide gas and the ozone gas. The control unit 7 is further connected to the dampers 11 and 12 and controls the opening and closing thereof. Hereinafter, the configuration of each unit will be described.

The hydrogen peroxide supply unit 2 has a configuration in which an ultrasonic vibrator 22 such as quartz is disposed inside a water storage tank 21 containing hydrogen peroxide water. Due to the ultrasonic vibration of the ultrasonic vibrator 22, the hydrogen peroxide solution in the water tank is atomized and H ₂ O ₂ gas is generated. Under the coexistence of H ₂ O ₂ gas and ozone, the hydrogen peroxide solution reacts, and active species are generated by the following reaction.
O ₃ + H ₂ O ₂ → OH · + O ₂ + HO ₂ ·
A communication port with the gas channel 10 is provided in the upper part of the hydrogen peroxide supply unit 2, and the generated active species are introduced into the gas channel 10. When this active species comes into contact with the exhaust gas flowing through the gas flow path 10, organic substances contained in the exhaust gas are decomposed.

  If the ozone gas supply part 3 can supply a fixed amount of ozone gas to the gas flow path 10, the structure will not be limited. The structural example of the ozone gas supply part 3 in this embodiment is shown in FIG.2 and FIG.3. FIG. 2 illustrates a UV irradiation chamber 3 a as the ozone gas supply unit 3. FIG. 3 illustrates an ozone gas generator 3 b as the ozone gas supply unit 3.

  It arrange | positions in the duct of the UV irradiation chamber 3a gas flow path 10. FIG. A plurality of straight tube type UV (ultraviolet) lamps 31 are arranged in the UV irradiation chamber 3a. Ozone gas is generated in the UV irradiation chamber 3a by absorbing the ultraviolet rays irradiated by the UV lamp 31 into oxygen. The UV lamps 31 are arranged such that the longitudinal axis direction thereof is substantially parallel to the gas flow path and spaced from each other by a predetermined distance. With this arrangement, ozone gas is uniformly supplied into the gas flow path 10.

  FIGS. 3A and 3B show an ozone gas generator 3 b that generates ozone by applying a high voltage to oxygen gas as the ozone gas supply unit 3. The ozone gas generator 3 b communicates with the gas flow path 10 through a duct and supplies the generated ozone gas to the gas flow path 10.

  The ozone gas generator 3b has a chamber 32 in which a discharge cell (not shown) is disposed, and the discharge cell is connected to a high-frequency high-voltage power source via an electric wire. An oxygen inlet 33 through which oxygen flows, a gas outlet 34 through which the generated ozone gas is discharged, a refrigerant inlet 35 through which cooling water as a refrigerant flows, and cooling water are discharged into the chamber 32 of the ozone gas generator 3b. A refrigerant discharge port 36 is provided. The oxygen inlet 33 is connected to an oxygen cylinder 37a shown in FIG. 3 (a) or an oxygen generator 37b shown in FIG. 3 (b). The oxygen generator 37b generates high concentration oxygen using compressed air. A cooling water circulation device 38 is connected to the refrigerant inlet 35 and the refrigerant outlet 36.

  Oxygen is supplied from the oxygen inlet 33 into the chamber 32, and a high voltage is applied to the discharge cell while supplying cooling water from the cooling water circulation device 38. The generated ozone gas is supplied to the gas flow path 10 through the gas discharge port 34.

  FIG. 3A shows an oxygen cylinder 37a as an oxygen supply source. However, as shown in FIG. 3B, an oxygen generator 37b that generates oxygen from compressed air may be used as the oxygen supply source. .

  In the present embodiment, the concentration of ozone gas supplied by the ozone gas supply unit 3 is set to about 15 ppm. Although there is no legal restriction on the concentration of ozone gas discharged to the outside air, it is desirable that the concentration is not too high considering the surrounding environment. Here, “about 15 ppm” means including a value in the range of ± 5 ppm.

  As shown in FIG. 1, two stages of filters 41 are stacked in the vertical direction inside the filter tower 4. A gas inlet 42 is provided in the lower part of the filter tower 4, and a gas outlet 43 is provided in the upper part, and each is connected to the gas flow path 10. The exhaust gas or the outside air that has flowed into the filter tower 4 from the gas flow path 10 flows from the bottom to the top inside the tower, passes through the filter 41, and is discharged from the gas discharge port 43. The ozone gas supplied to the gas flow path 10 by the ozone gas supply unit 3 also enters the filter tower 4 from the gas inlet 42 and is supplied to the filter 41.

As the filter 41, a filter having both an organic substance adsorption function and an ozone gas decomposition function is used. FIG. 4 shows an example of the filter 41. This filter 41 has a configuration in which a bag-filled adsorbent 41a is placed in a tray 41b having a meshed surface on both sides. As the adsorbent 41a, for example, silica-alumina gel blended with activated carbon (silicon dioxide) in a fine powder state and formed into a granular shape (trade name “Secard”), or activated carbon mainly composed of coconut shell or the like is used as a carrier. What carried | supported the substance (potassium carbonate) and the oxidizing substance (potassium iodate) (brand name "PureLite A3H") can be used. Secard and PureLite A3H adsorb organic substances and simultaneously decompose ozone gas as shown in the following chemical formula.
C + 2O ₃ = CO ₂ + 2O ₂

  When decomposing ozone gas, active species are generated. The organic matter adsorbed on the filter 41 is decomposed by the active species. Of course, the adsorbent 41a is not limited to the above-described one, and various types of combinations of activated carbon that adsorbs organic matter and an ozone gas decomposition catalyst can be used as appropriate.

  The thickness of the first stage of the filter 41 is about 20 cm, and the thickness of the second stage is about 40 cm. There may be no gap between the two stages of filters 41, or a slight gap may be formed. Here, “about” means including a value in a range of ± 1 cm. By setting the thickness of the filter 41 to about 20 cm, even ozone gas having a low concentration of about 15 ppm reaches the two-stage filter 41 and is decomposed in the filter 41 without flowing out to the outside.

  A pre-filter 44 is disposed in front of the two-stage filter 41. The prefilter 44 is made of glass fiber carrying an ozonolysis catalyst. As an ozonolysis catalyst, at least one metal selected from manganese, copper, nickel, zinc, iron, titanium, and cobalt, a catalyst made of these oxides, and a composite thereof is used as a filter base material by ion exchange or impregnation. Those attached to can be used. For example, manganese dioxide and nickel oxide are used. Also in the pre-filter 44, ozone gas is preliminarily decomposed.

  A post filter 45 having the same configuration as that of the pre-filter 44 is also installed after the two-stage filter 41. This is to prevent ozone gas from being released to the atmosphere when the ozone decomposition catalyst deteriorates and the ozone decomposition efficiency deteriorates.

  As shown in FIG. 5, the exhaust gas treatment apparatus 1 further includes a timer 9 that measures time and a storage unit 8 that stores information related to the operation schedule of the facility. The facility operation schedule is information indicating whether the facility is operating or stopped every hour and every day. For example, in the case of a factory where a 24-hour line operates on weekdays, information indicating operation is stored for each time on weekdays, and information indicating operation stop is stored for each time on holidays.

  The control unit 7 is connected to the timer 9 and the storage unit 8. The control unit 7, the timer 9, and the storage unit 8 constitute a gas switching unit that switches the gas flowing through the gas flow path 10. That is, the control unit 7 performs opening / closing control of the dampers 11 and 12 with reference to the time measured by the timer 9 and information on the operation schedule of the facility in the storage unit 8.

  Specifically, while the facility is in operation, the control unit 7 sets the damper 11 to “open” and the damper 12 to “close” so that the exhaust gas is supplied to the gas flow path 10. As a result, when the facility is in operation, the exhaust gas treatment apparatus 1 adsorbs the organic substances contained in the exhaust gas with the filter 41 to deodorize the exhaust gas, and simultaneously performs a process of decomposing the adsorbed organic substances using ozone gas (hereinafter simply referred to as “exhaust gas”). Also called “exhaust gas deodorization treatment”). On the other hand, when the facility stops operating, the control unit 7 switches the damper 11 to “closed” and the damper 12 to “open” so that the outside air is supplied to the gas flow path 10. Thereby, when the facility is not in operation, the exhaust gas treatment apparatus 1 performs a process of intensively decomposing the organic matter accumulated in the filter 41 using ozone gas and recovering the filter 41 (hereinafter simply referred to as “filter”). Also referred to as “recovery process”.)

(Function)
The operation of the exhaust gas treatment apparatus 1 of the present embodiment will be described separately for exhaust gas deodorization processing during facility operation and filter recovery processing during operation stop.

(At the time of facility operation)
The control unit 7 refers to the operation information of the timer 9 and the storage unit 8 and sets the damper 11 to “open” and the damper 12 to “close” at the time when the facility operation starts.

  Exhaust gas containing organic matter generated by the operation of the facility flows from the damper 11 into the gas flow path 10. In the gas flow path 10, the exhaust gas first comes into contact with activated species of hydrogen peroxide gas generated by the hydrogen peroxide supply unit 2. As a result, a part of the organic matter contained in the exhaust gas is decomposed.

  Next, the exhaust gas passes through the ozone gas supply unit 3 and enters the filter tower 4. On the other hand, the ozone gas generated by the ozone gas supply unit 3 also enters the filter tower 4 while coexisting with the exhaust gas. A part of the ozone gas is decomposed into active species by contacting the ozone decomposition catalyst in the pre-filter 44 disposed in front of the filter 41. When this active species comes into contact with the exhaust gas, a part of the organic matter contained in the exhaust gas is further decomposed.

  The exhaust gas that has passed through the pre-filter 44 then passes through the two-stage filter 41. Here, the organic matter remaining in the exhaust gas is adsorbed by the filter 41 and removed. The exhaust gas from which the organic matter has been removed and deodorized passes through the post filter 45 and is discharged from the filter tower 4, and further down the gas flow path 10 and through the exhaust hood or exhaust gallery 14 to the outside of the facility.

  The ozone gas that has passed through the prefilter 44 also enters the filter 41. Here, ozone gas is decomposed in contact with an ozone decomposition catalyst supported on activated carbon. Active species are generated during the decomposition of ozone gas, and the active species decompose a part of the organic matter adsorbed on the activated carbon.

  In this way, exhaust gas deodorization processing is performed during facility operation. The organic matter adsorbed on the filter 41 is decomposed by ozone gas, but when the amount of organic matter exceeds the amount decomposed by ozone gas, the organic matter adsorbed on the filter 41 gradually accumulates, and the organic matter removing ability of the filter 41 is time. It goes down over time.

(When the facility is stopped)
The control unit 7 refers to the operation information of the timer 9 and the storage unit 8 and sets the damper 11 to “closed” and the damper 12 to “open” at the time when the facility operation stops. At the same time, the operation of the hydrogen peroxide supply unit 2 is stopped.

  Outside air is introduced into the gas flow path 10 from the damper 12 in place of the exhaust gas containing organic matter. Outside air passes through the ozone gas supply unit 3 and the filter tower 4 and is discharged outside the facility. Since the organic matter contained in the outside air is very small, the organic matter is hardly adsorbed on the filter 41 of the filter tower 4.

  On the other hand, ozone gas generated in the ozone gas supply unit 3 enters the filter tower 4 while coexisting with the outside air, and is decomposed by the prefilter 44 or the filter 41. The active species generated when the ozone gas is decomposed decomposes organic substances accumulated in the filter 41 when the facility is operating.

  As described above, when the facility is shut down, the filter recovery process for intensively decomposing organic substances accumulated in the filter 41 is performed periodically. As a result, the adsorption performance of the filter 41 that has been reduced due to the accumulation of organic matter is recovered.

(Example)
An example of the exhaust gas treatment apparatus 1 of the present embodiment will be described. Exhaust gas treatment was performed under the following conditions.
・ Period: Assuming a factory that operates for 8 hours a day on weekdays, the exhaust gas treatment device 1 was run over a week.
・ Operating hours: Monday to Friday, daytime: Exhaust gas + ozone gas for 8 hours
Monday to Friday night… Air and ozone gas for 16 hours
Saturday, Sunday ... Air + ozone gas for 24 hours ・ Number of filter stages: 1 stage ・ Ozone gas concentration: about 15 ppm
・ Organic substances contained in exhaust gas and their concentrations: organic compounds mainly composed of menthol (TVOC), average 80,000 μg / m ³

(Comparative example)
Next, as a comparative example of the exhaust gas treatment apparatus 1 of the present embodiment, exhaust gas treatment was performed under the following implementation conditions.
・ Period: Assuming a factory that operates for 8 hours a day on weekdays, the exhaust gas treatment device 1 was run over a week.
・ Operating hours: Monday to Friday daytime ... only exhaust gas is ventilated for 8 hours
Monday to Friday night and Saturday, Sunday ... The exhaust gas treatment device 1 is stopped.
-Number of filter stages: 1 stage-Organic substances contained in exhaust gas and their concentrations: Organic compounds mainly composed of menthol (TVOC), average 80,000 μg / m ³

  The experimental results of the above example are shown in the table of FIG. 6, and the experimental results of the comparative example are shown in the table of FIG. As can be seen from the experimental results, the example maintains a higher VOC removal rate for a longer period than the comparative example. This is because the adsorption performance of the filter is restored by switching from exhaust gas to outside air at night and on Saturdays and Sundays when the factory is shut down, and by concentrating and decomposing organic substances accumulated in the filter. .

(effect)
(1) The exhaust gas treatment apparatus 1 is provided in the gas flow path 10, and performs a filter 41 that adsorbs organic substances and decomposes ozone gas, an ozone gas supply unit 3 that supplies ozone gas to the filter 41, and a gas flow path 10. A gas switching unit that switches between introduction of exhaust gas containing organic substances and introduction of outside air. By introducing exhaust gas containing organic matter into the gas flow path 10, the filter 41 adsorbs organic matter and decomposes ozone gas supplied from the ozone gas supply unit 3 to generate active species, and uses the active species. Then, the adsorbed organic matter is decomposed. On the other hand, by introducing outside air into the gas flow path 10, organic substances accumulated in the filter 41 are concentrated and decomposed.

  By switching the gas flowing through the gas flow path 10 from the exhaust gas to the outside air, the organic matter accumulated in the filter 41 can be intensively decomposed and the adsorption performance of the filter 41 can be recovered. Thereby, even when low-concentration ozone gas is used, the filter 41 can be made to last longer, the replacement cost can be reduced, and the economy is excellent. In addition, since the filter 41 can be regenerated simply by switching the gas flowing through the gas flow path 10, easy control is possible.

(2) The filter 41 can be efficiently regenerated by determining the timing for switching from exhaust gas to outside air according to the operation schedule of the facility where the gas flow path 10 is provided. For example, in a chemical factory or the like, exhaust gas containing organic substances is not discharged on a holiday when the factory line stops. Therefore, the adsorption performance of the filter 41 can be periodically recovered by efficiently performing the recovery process of the filter 41 using this holiday time.

(3) The concentration of ozone gas was about 15 ppm, and the filter 41 was arranged in two stages inside the filter tower 4 and one sheet had a thickness of about 20 cm. If the concentration of ozone gas is low considering the surrounding environment, the ozone gas may not reach the depths of the filter 41 and the decomposition process may not be performed sufficiently. However, one filter 41 is set to 20 cm. By overlapping two stages, it is possible to prevent the ozone gas from reaching the depth of the filter 41 and, conversely, the ozone gas that is not decomposed from flowing out to the outside.

(4) The ozone gas supply unit 3 includes a straight tube type UV lamp 31 disposed substantially parallel to the direction in which the exhaust gas flows. By being arranged substantially parallel to the direction in which the exhaust gas flows, the generated ozone gas can easily come into contact with the exhaust gas. As a result, when ozone gas enters the filter 41 and active species are generated, the active species can easily come into contact with organic matter contained in the exhaust gas, and the organic matter can be efficiently decomposed.

(5) The ozone gas supply unit 3 includes an ozone gas generator 3b that generates ozone gas using oxygen gas. It may be desirable to adjust the concentration of ozone gas depending on the concentration of organic matter contained in the exhaust gas. The ozone gas generator 3b can easily adjust the concentration of ozone gas by adjusting the oxygen supply amount.

(6) The exhaust gas treatment apparatus 1 further includes a hydrogen peroxide supply unit 2 that supplies hydrogen peroxide gas to the gas flow path 10. Hydrogen peroxide gas self-decomposes to generate active species. This active species comes into contact with the organic matter contained in the exhaust gas flowing through the gas flow path 10 and decomposes the organic matter. By supplying hydrogen peroxide gas in addition to ozone gas, the processing efficiency of organic matter decomposition can be improved.

[Second Embodiment]
An exhaust gas treatment apparatus 1 according to a second embodiment of the present invention will be described with reference to FIGS. 8 and 9.
In the second embodiment, only points different from the first embodiment will be described, and the same parts as those in the first embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

(Configuration and action)
In the present embodiment, the exhaust gas treatment apparatus 1 further includes a VOC meter 5 as a gas switching unit. As shown in FIG. 8, the VOC meter 5 is arranged in the vicinity of the gas outlet 43 on the downstream side of the filter tower 4. The VOC meter 5 measures the amount of organic matter contained in the exhaust gas that has passed through the filter 41 during facility operation. The measurement result is temporarily stored in the storage unit 8. In the first embodiment, switching between the exhaust gas deodorization process and the filter recovery process is periodically performed based on the time measured by the timer 9. In the present embodiment, in addition to this, when the filter 41 is in a breakthrough state, switching from the exhaust gas deodorization process to the filter recovery process is performed based on the measured value of the organic matter by the VOC meter 5.

  For this purpose, the storage unit 8 stores the maximum value of the measured amount measured by the VOC meter 5 as the reference value A in addition to the facility operation information.

  As the amount of organic matter adsorbed on the filter 41 increases, the adsorption performance of the filter 41 gradually decreases. As the adsorption performance of the filter 41 decreases, the concentration of organic substances contained in the exhaust gas that has passed through the filter 41 increases, and thereby the amount of organic substances measured by the VOC meter 5 also increases. When the organic matter adsorbed by the filter 41 reaches a saturation amount, the filter 41 cannot perform further adsorption and enters a breakthrough state. On the other hand, the measured value with the VOC meter 5 becomes the maximum, and the maximum value is maintained thereafter unless the concentration of the organic matter contained in the exhaust gas is changed.

  Therefore, the reference value A indicates that the filter 41 is in a breakthrough state. The control unit 7 compares the measured value with the reference value A during the exhaust gas deodorization process. When the measured value reaches the reference value A, the control unit 7 controls the opening and closing of the dampers 11 and 12 to restore the filter 41. Switch to. As a result, when the organic matter accumulates in the filter 41 and becomes a breakthrough state, it is possible to switch to the recovery process of the filter 41 even while the facility is in operation.

  It should be noted that when the recovery of the filter 41 is completed, it is desirable to switch to the exhaust gas deodorization process again. The time required for the recovery of the filter 41 may be set in advance, and after that time, the exhaust gas deodorization process may be switched. Alternatively, another reference value B indicating that the filter 41 has been recovered may be stored in the storage unit 8, and when the measured value with the VOC meter 5 has decreased to the reference value B, switching to the exhaust gas deodorizing process may be performed.

  The reference value B is preferably a value near zero of the measured value by the VOC meter 5. Even when outside air flows through the gas flow path 10, while the organic matter is accumulated in the filter 41, the outside air that has passed through the filter 41 is in a state in which some organic matter is contained. Therefore, the VOC meter 5 measures a certain amount of organic matter. Therefore, the value near zero of the measured value is a value indicating that the organic matter accumulated in the filter 41 is decomposed and the recovery of the adsorption performance of the filter 41 is completed.

  Further, the adsorption performance of the filter 41 need only be restored by the amount necessary for the remaining operation time of the facility, even if it is not completely restored. Therefore, the time for performing the recovery process may be calculated based on the remaining operation time, and when the time has elapsed, the process may be switched to the exhaust gas deodorization process again. In this case, the adsorption performance of the filter 41 can be sufficiently recovered by periodic filter recovery processing when the facility is stopped.

(effect)
In the present embodiment, the gas switching unit includes the VOC meter 5 as an organic matter sensor that measures the amount of organic matter contained in the exhaust gas that has passed through the filter 41. When the amount of organic matter measured by the VOC meter 5 reaches the reference value A, the control unit 7 switches from introduction of exhaust gas to introduction of the outside air.

  In addition to performing the recovery of the filter 41 by using the operation stop time, the state of the filter 41 can be changed by switching to the recovery process when the filter 41 is in a breakthrough state even during the operation time. It is possible to provide a highly flexible exhaust gas deodorizing apparatus according to the above.

[Third Embodiment]
An exhaust gas deodorizing apparatus according to a third embodiment of the present invention will be described with reference to FIG.
In the third embodiment, only points different from the first embodiment will be described, and the same parts as those in the first embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

(Constitution)
The exhaust gas treatment apparatus 1 according to the third embodiment of the present invention connects a hydrogen peroxide supply unit 2 and an ozone gas supply unit 3 to each of a plurality of gas flow paths, and further includes filter towers 401 and 402 in each gas flow path. It has a configuration provided.

  The plurality of gas flow paths can be provided as branch ducts branched from the main duct. In FIG. 10, the structure provided in the two gas flow paths 100 and 200 is illustrated. Dampers 111 and 211 are provided between the respective gas flow paths 100 and 200 and the main duct, and the gas flow paths into which the exhaust gas flows are switched by opening and closing the dampers 111 and 211. In addition, dampers 112 and 212 for introducing outside air are provided in the gas flow paths 100 and 200, respectively. In the gas flow path 100, a hydrogen peroxide supply unit 2, an ozone gas supply unit 3, a filter tower 401, and a VOC meter 501 are provided in this order from the upstream side. Similarly, in the gas flow path 200, a hydrogen peroxide supply unit 2, an ozone gas supply unit 3, a filter tower 402, and a VOC meter 502 are provided in this order from the upstream side.

As shown in FIG. 10, the hydrogen peroxide supply unit 2 and the ozone gas supply unit 3 are shared by the gas flow paths 100 and 200. Supplying and stopping of the hydrogen peroxide gas and the ozone gas to the gas flow paths 100 and 200 are switched by opening and closing valves provided on the pipes, which are connected to the gas flow paths 100 and 200 by pipes.
Note that the hydrogen peroxide supply unit 2 or the ozone gas supply unit 3 may not be shared by the gas flow paths 100 and 200 but may be provided separately in the gas flow paths 100 and 200.

  Although not shown in FIG. 10, the exhaust gas treatment apparatus 1 includes a control unit 7 as in the first embodiment. The control unit 7 is connected to the dampers 111, 211, 112, 212, the valves of the hydrogen peroxide supply unit 2 and the ozone gas supply unit 3, and the VOC meters 501, 502, and controls each unit.

(Function)
In the exhaust gas treatment apparatus 1 of the third embodiment, when the exhaust gas deodorization process is performed in one gas flow path 100 and the filter 401 is in a breakthrough state, the gas flow path 100 is switched to the filter recovery process, and instead In one gas flow path 200, exhaust gas deodorization processing is started. As the switching timing, the reference value A stored in the storage unit 8 can be used as in the second embodiment.

  That is, when the measured value of the VOC meter 501 provided in the gas flow path 100 reaches the reference value A, the control unit 7 closes the damper 111 of the gas flow path 100 and stops the inflow of exhaust gas. At the same time, the damper 112 is opened, and the outside air flows into the gas flow path 100. The valve of the pipe connecting the hydrogen peroxide supply unit 2 and the gas flow path 100 is closed, but the valve of the pipe connecting the ozone gas supply unit 3 and the gas flow path 100 is kept open. The organic substance accumulated in the filter 401 is decomposed by the ozone gas supplied from the ozone gas supply unit 3 to the gas flow path 100, and the adsorption performance of the filter 401 is restored.

  At the same time as switching the gas flow path 100 to the filter recovery process, the exhaust gas deodorization process is started in the gas flow path 200. Specifically, the control unit 7 opens the damper 211 of the gas flow path 200 and causes the exhaust gas to flow into the gas flow path 200. A valve of a pipe connecting the hydrogen peroxide supply unit 2 and the ozone gas supply unit 3 and the gas flow path 200 is opened, and hydrogen peroxide gas and ozone gas are supplied to the gas flow path 200. The exhaust gas is deodorized in the filter tower 402 of the gas flow path 200.

  When the filter of the gas flow path 200 approaches a breakthrough state, this time, the gas flow path 200 is switched to the filter recovery process, and the gas flow path 100 that has recovered the adsorption performance of the filter 401 is switched again to the exhaust gas deodorization process.

(effect)
As described above, in the present embodiment, when there are a plurality of gas flow paths 100 and 200, the filter and the ozone gas supply unit 3 are provided in each of the gas flow paths 100 and 200. When the gas switching unit switches from introduction of exhaust gas to introduction of outside air in one gas flow channel 100, the gas switching unit starts introduction of exhaust gas in the other gas flow channel 200. As a result, even in a factory where the 24-hour line is operating or a factory where the operation stop time is short, it is possible to ensure a sufficient time for regenerating the filter, and to provide a highly efficient exhaust gas treatment apparatus 1. it can.

  When exhaust gas containing a high concentration of organic matter is temporarily generated, exhaust gas can be quickly treated by simultaneously performing exhaust gas deodorization treatment in a plurality of gas flow paths 100 and 200. is there.

[Other Embodiments]
(1) The present invention is not limited to the above-described embodiments as they are, and the constituent elements can be appropriately modified without departing from the gist thereof. Moreover, you may combine suitably the some component currently disclosed by the above-mentioned embodiment. For example, some constituent elements may be deleted from the constituent elements shown in the above-described embodiments, and constituent elements over different embodiments may be appropriately combined.

(2) In the filter recovery process during the facility stoppage described in the first embodiment, the required recovery time of the filter 41 may be calculated in advance, and the recovery process may be terminated when the time has elapsed. That is, the operation of the ozone gas supply unit 3 may be stopped, and the exhaust gas treatment device may be shifted to the standby mode until the facility starts operating. Alternatively, when the measured value reaches the reference value B using the VOC meter 5 described in the second embodiment, it is determined that the recovery of the filter 41 is completed, the disassembly process is terminated, and the standby mode is switched. You can also.

(3) In the first embodiment, the control unit 7 performs the opening / closing control of the dampers 11 and 12 based on the time measurement result of the timer 9 and the operation information for each time stored in the storage unit 8. However, the present invention is not limited to this. For example, the timer 9 may be provided with an ON-OFF contact output function, and the process may be switched in an analog manner. When this analog method is used, it is not necessary to store operation information in the storage unit 8.

(4) In the above-described embodiment, when the filter 41 is intensively recovered, the outside air is introduced into the gas flow path 10, but the outside air is not limited to the one that is taken in from outside the facility. For example, a gas discharged from a place other than the factory line of the facility may be introduced as long as it does not contain organic substances to the extent that the performance of the filter 41 is degraded.

(5) The filter 41 is not limited to the materials and configurations described in the above embodiment as long as it can adsorb organic substances and decompose ozone gas. For example, a porous material such as activated carbon or zeolite carrying an ozone decomposition catalyst such as manganese may be used. Or you may use what laminated | stacked the porous material and ozone decomposition catalyst which were shape | molded in the separate plate shape, and accommodated in the tray 41b.

1 Exhaust gas treatment device 2 Hydrogen peroxide supply unit
3 Ozone gas supply unit 4 Filter tower 5 VOC meter 7 Control unit 8 Storage unit 9 Timer 10 Gas flow path 11, 12 Damper 13 Exhaust fan 14 Exhaust hood or exhaust gallery 21 Reservoir 22 Ultrasonic vibrator 3a UV irradiation chamber 31 UV Lamp 3b Ozone gas generator 32 Chamber 33 Oxygen inlet 34 Gas outlet 35 Refrigerant inlet 36 Refrigerant outlet 37a Oxygen cylinder 37b Oxygen generator 38 Cooling water circulation device 41 Filter 41a Adsorbent 41b Tray 42 Gas inlet 43 Gas outlet 44 Prefilter 45 Postfilter 100, 200 Gas flow path 111, 112, 211, 212 Damper 401, 402 Filter tower 501, 502 VOC meter

Claims (10)

A filter provided in the gas flow path for adsorbing organic matter and decomposing ozone gas;
An ozone gas supply unit for supplying ozone gas to the filter;
A gas switching unit that switches between introduction of exhaust gas containing organic substances and introduction of outside air into the gas flow path, and introduces the exhaust gas into the gas flow path to adsorb organic substances contained in the exhaust gas in the filter In addition, the ozone gas supplied from the ozone gas supply unit is decomposed to generate active species, and the adsorbed organic matter is decomposed using the active species,
An exhaust gas treatment apparatus, wherein the outside air is introduced into a gas flow path, and organic substances accumulated in the filter are decomposed using the active species.   The exhaust gas processing apparatus according to claim 1, wherein the gas switching unit switches between introduction of the exhaust gas and introduction of the outside air based on an operation schedule of a facility provided with the gas flow path. The gas switching unit includes an organic matter sensor that measures the amount of organic matter contained in the exhaust gas that has passed through the filter,
The exhaust gas treatment apparatus according to claim 1 or 2, wherein when the amount of organic matter measured by the organic matter sensor reaches a predetermined amount, the introduction of the exhaust gas is switched to the introduction of the outside air. The concentration of ozone gas supplied by the ozone gas supply unit is about 15 ppm,
The exhaust filter according to any one of claims 1 to 3, wherein the filters are arranged in two stages inside the filter tower, and one filter has a thickness of about 20 cm.   The exhaust gas treatment according to any one of claims 1 to 4, wherein the filter includes an adsorbent formed by mixing fine powder or granular activated carbon with a mineral mainly composed of silica-alumina. apparatus.   The exhaust gas treatment apparatus according to any one of claims 1 to 4, wherein the filter includes an adsorbent in which alkali metal is supported on activated carbon.   The exhaust gas treatment apparatus according to any one of claims 1 to 6, wherein the ozone gas supply unit includes a straight tube type UV lamp disposed substantially parallel to the gas flow path.   The exhaust gas treatment apparatus according to claim 1, wherein the ozone gas supply unit includes an ozone gas generator that generates ozone gas using oxygen gas or air.   The apparatus further comprises a hydrogen peroxide gas supply unit that supplies hydrogen peroxide gas to the gas flow path and decomposes organic substances contained in the exhaust gas using activated species generated by decomposition of the hydrogen peroxide gas. The exhaust gas treatment apparatus according to any one of claims 1 to 8. The gas flow path is a plurality of gas flow paths, and the filter and the ozone gas supply unit are provided in each gas flow path,
The gas switching unit starts introduction of the exhaust gas in at least one of the other gas passages when switching from introduction of the exhaust gas into introduction of the outside air in one gas passage. The exhaust gas treatment apparatus according to any one of 1 to 9.

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