JP4618191B2 - Discharge reactor and gas treatment device - Google Patents

Description

The present invention relates to a discharge reactor that purifies air by adsorbing organic substances in the air, and a gas processing apparatus including the discharge reactor.

In places where a large amount of organic solvent is used, volatile organic compounds (VOC) are contained in the air, and if it is released into the atmosphere as it is, it will have a serious impact on the environment. It has been. For this reason, it is necessary to remove VOC in the air and render it harmless before releasing it to the atmosphere. Accordingly, a discharge reactor has been devised in which air containing VOC is passed through an adsorbent carrying an adsorbent to adsorb and remove VOC components, and the adsorbent is regenerated by discharge treatment and can be used repeatedly. (For example, refer to Patent Document 1).
On the other hand, a fluid filter of a three-dimensional framework structure ceramic porous body having an internal communication space with low pressure loss is shown. (For example, refer to Patent Document 2).

JP-A-2005-230627 (pages 4-6, Fig. 1) Japanese Unexamined Patent Publication No. 2004-223482 (Page 4, Figure 2)

The fluid filter of the three-dimensional skeleton structure ceramic porous body as described above is formed by forming a synthetic resin foam in a corrugated plate shape or a cylindrical shape, attaching a ceramic slurry thereto, and firing it. Therefore, it is difficult to uniformly attach the ceramic slurry to the corrugated or cylindrical shaped body, and the formed communication space is not uniform. Therefore, even if an adsorbent is formed on a three-dimensional skeleton structure ceramic porous body manufactured by such a method to form an adsorbent and used in the above discharge reactor, the gas flow becomes uneven, and the adsorbent It was difficult to obtain a sufficient reaction efficiency.

The present invention has been made to solve the above-described problems, and provides a discharge reactor having low pressure loss and high reaction efficiency.

In the discharge reactor according to the present invention, a flat synthetic resin foam having a ceramic slurry attached is curved and molded in a discharge space formed between electrodes, and then the substrate obtained by firing is coated with an adsorbent material. A cylindrical adsorbent made of a three-dimensional skeleton structure ceramic porous body having a communication space inside is provided.

According to the present invention, a three-dimensional skeletal structure ceramic porous body having a communication space inside is coated with an adsorbent on a substrate obtained by curving and molding a flat synthetic resin foam to which ceramic slurry is adhered. By using a cylindrical adsorbent made of a body, the communication space can be made uniform, and a discharge reactor with high reaction efficiency can be obtained.

Embodiment 1 FIG.
1 to 4 show a discharge reactor according to Embodiment 1 of the present invention. FIG. 1 is a front view thereof, FIG. 2 is a side view, and FIG. 3 is a cross-sectional view taken along line III-III in FIG. 4 is a longitudinal sectional view taken along line IV-IV in FIG. In the figure, a discharge reactor 1 is formed in an elongated cylindrical shape, and an inner peripheral surface thereof is a SUS high-voltage electrode 2 having a glass tube dielectric 2A in close contact with the outer surface, that is, a first electrode, and an outer peripheral surface. Is composed of a ground electrode 3 made of SUS provided around the first electrode, that is, a second electrode, and insulating covers 4 at both ends, and has a sealed structure. In the discharge space 5 formed between the high-voltage electrode 2 as the first electrode and the ground electrode 3 as the second electrode, a flat synthetic resin foam to which ceramic slurry is attached is curved as will be described later. A cylindrical adsorbent body 6 made of a three-dimensional skeleton structure ceramic porous body having a communicating space inside is formed by coating a base obtained by firing after molding with an adsorbent material. The adsorbing body 6 has a semi-cylindrical adsorbing plate 6A that is divided into two in the circumferential direction as shown in FIG.

On one side of the ground electrode 3, a processing gas supply port 3 </ b> A is provided for introducing a processing gas into the discharge space 5. On the other side, a gas discharge port 3B for discharging the processed gas is provided opposite to the processing gas supply port 3A. In the present embodiment, the processing gas supply port 3A and the gas discharge port 3B are configured by a plurality of rows of holes arranged regularly in the axial direction alternately in a certain width as shown in FIG. One of the covers 4 is provided with a replacement gas supply port 4A for introducing a replacement gas into the discharge reactor 1 as shown in FIGS. The high-voltage electrode 2 is connected to the high-voltage conductor 8 extending in the axial direction on the inner side thereof, so that a high voltage from the power source can be applied uniformly in the axial direction.

Next, the operation of this discharge reactor will be described.
When air is supplied from the processing gas supply port 3A, it flows in the adsorbent 6 in the circumferential direction as shown by the arrows in FIG. 3, and is discharged from the gas exhaust port 3B. At this time, the air flows in the communication space of the adsorbent 6 covered with the adsorbent. The VOC component contained in the supplied air is adsorbed and removed by the adsorbent coated on the surface of the communication space of the adsorbent 6, and clean air that does not contain VOC comes out from the gas exhaust port 3B. This is a gas processing step for cleaning air containing VOC by adsorption.

Subsequently, the supply of air from the processing gas supply port 3A is stopped, and oxygen is supplied from the replacement gas supply port 4A shown in FIGS. The amount of oxygen remaining in the adsorbent 6 is discharged from the gas exhaust port 3B, and the supply of oxygen is stopped when the oxygen concentration reaches 50%. Here, when an alternating high voltage of several kV is applied between the ground electrode 3 and the high voltage electrode 2, discharge plasma is generated in the discharge space 5. By this discharge plasma, the adsorbed VOC component is desorbed from the adsorbent 6, reacts with oxygen, and is decomposed into water and carbon dioxide. As a result, the adsorbent 6 is regenerated and returns to a state in which the VOC can be adsorbed and removed. This is a regeneration process of the adsorbent 6 by a discharge reaction. During the regeneration process, the temperature of the adsorbent 6 rises to about 100 ° C., and the decomposed water and carbon dioxide gas are discharged as gases from the gas exhaust port 3B.

Next, the manufacturing method of the adsorbent 6 described above will be described.
First, in order to attach a ceramic slurry to a synthetic resin foam, a flat synthetic resin foam is immersed in the ceramic slurry. Here, the synthetic resin foam is a flat polyurethane foam (Everlight SF, trade name: HR-30 manufactured by Bridgestone Corporation) having a three-dimensional skeleton structure having a communication space inside and having no cell membrane. use. The ceramic slurry is adjusted to alumina: 94% by weight, Sasame clay: 3% by weight, and talc: 3% by weight. Then, the synthetic resin foam is lifted from the ceramic slurry, and the excess slurry is removed to obtain a flat synthetic resin foam half-molded body 9 to which a desired amount of the ceramic slurry is adhered. In the present embodiment, two cylindrical rolls (not shown) are squeezed from both sides with a flat plate lifted from the ceramic slurry, and after excess slurry is removed, the amount of ceramic slurry deposited is reduced by compressed air blow. Adjust to the desired amount. Thereby, ceramic slurry adheres uniformly to a flat plate.

Subsequently, the semi-molded body 9 in a semi-dried state is put into a mold and dried to form a molded body 90. FIG. 5 is a perspective view of the first mold 10 used in this step, and FIG. 6 is a perspective view of the second mold 12. The first mold 10 is for simultaneously molding three suction plates 6A constituting the adsorbent body 6, and has three installation surfaces 11 each having a concave curved surface corresponding to the outer diameter of the discharge space 5. Further, the second mold 12 has three pressing surfaces 13 formed of convex curved surfaces corresponding to the installation surface 11 of the first mold 10. In addition, the shape of the pressing surface 13 is adjusted in consideration of shrinkage during firing described later. The semi-molded product 9 in a semi-dried state is placed on the installation surface 11 one by one while supporting both ends, and installed on the first mold 10 along the installation surface 11 as shown in FIG. At this time, the semi-molded body 9 is deformed along the installation surface 11 by its own weight because moisture remains so as not to lose flexibility. Next, the molded body 90 is formed in a state of being curved into a predetermined shape as shown in FIG. 8 by sandwiching the semi-molded body 9 from both sides using the second mold 12 and drying. At this time, as shown in FIG. 8, there is a gap corresponding to the thickness shrinkage at the time of firing as described later between the first mold 10 and the second mold 12. Although it is possible to dry without using the second mold 12, it is desirable to press from both sides in order to suppress deformation during drying.

Further, the molded body 90 is fired to obtain the base body 900. The molded body 90 is introduced into a firing furnace while being sandwiched from both sides by the molding dies 10 and 12 used in the drying step, and is fired. By firing, the synthetic resin foam is burned out and the adhered ceramic material is sintered. At this time, shrinkage of about 20% occurs in both the circumferential direction and the thickness direction, but the outer circumferential portion is kept in a shape along the installation surface 11 by its own weight. Further, as shown in FIG. 9, the gap between the first mold 10 and the second mold 12 described above sinks as the thickness of the molded body 90 changes during firing, and defines the inner peripheral portion at the final stage of firing. To do.

Finally, a VOC adsorbent is supported. Hydrophobic zeolite fine particles, which are VOC adsorbents, are made into a slurry, impregnated into the substrate 900, dried, and then fired. The hydrophobic zeolite is calcined at a temperature lower than the calcining temperature of the substrate 900 and thinly adheres to the wall surface of the internal communication space formed in the substrate 900. Thus, the adsorption plate 6A covered with the adsorbent while maintaining the shape of the base 900 is formed.

In order to confirm the performance of the adsorbent 6 manufactured by the above method, a predetermined amount of processing gas is allowed to flow through the discharge reactor 1, pressure loss (pressure difference between the processing gas supply port 3A and the gas exhaust port 3B), and the adsorption rate (concentration). The standard mass transfer coefficient was used as a parameter for the adsorption rate). Measurement conditions were such that air containing 10 ppm of toluene as a processing gas was supplied from the processing gas supply port 3 </ b> A so as to have a linear velocity of 1 m / s in the discharge space 5. Moreover, two types of adsorbents were prepared as comparative examples and measured under the same test conditions. In Comparative Example 1, when a pellet obtained by adding a binder such as clay to a generally available adsorbent and extruding pellets is used, Comparative Example 2 is obtained by molding a synthetic resin foam into a cylindrical shape by a conventional manufacturing method. This is a case where an adsorbent is supported on a ceramic porous body formed by adhering ceramic slurry. In Comparative Example 2, deformation during adhering or firing of the ceramic slurry cannot be suppressed, and the adsorbent is shaved for installation in the discharge space 5.

According to the above measurement, the pressure loss of Comparative Example 1 was 13.0 Pa, whereas the pressure loss of the present embodiment and Comparative Example 2 was 5.0 Pa, and the ceramic having a communication space therein. It was found that the pressure loss can be greatly reduced by using the porous body as the adsorbent.

Moreover, about adsorption | suction speed | velocity in this Embodiment, it increased 3.8 times of the comparative example 1, and it turned out that the effect of improving adsorption | suction efficiency is also high. On the other hand, in Comparative Example 2, a high adsorption rate could not be obtained as in the present embodiment. In Comparative Example 2, since the ceramic slurry was attached to the synthetic resin foam formed into a cylindrical shape by a conventional method, the slurry could not be uniformly attached, and it was difficult to form the internal communication space uniformly. It becomes. Therefore, the gas flow is uneven and only a part of the adsorbent functions, and the substantial adsorption efficiency is lowered. Also, with the conventional method, it is difficult to control deformation in the manufacturing process. Therefore, in order to apply to the discharge reactor 1 that requires dimensional accuracy, it is necessary to grind a hard and brittle ceramic porous body, resulting in an increase in cost.

On the other hand, in this embodiment, since the ceramic slurry is adhered to the flat synthetic resin foam, the amount of adhesion can be made uniform by removing the surplus by a method such as pressing or air blowing. . Therefore, since the communication space is formed uniformly, the gas flows evenly in the communication space, and the adsorbent carried in the communication space functions in the entire adsorbent 6 to improve the adsorption performance. That is, a cylinder made of a ceramic porous body having a three-dimensional skeleton structure having a communication space inside a base material obtained by coating a substrate obtained by curving and molding a flat synthetic resin foam impregnated with ceramic slurry with an adsorbing material By forming the adsorbent body 6 in the form of a uniform communication space, the pressure loss can be reduced and the entire adsorbent body 6 can function to improve the reaction efficiency.

The discharge space 5 of the discharge reactor 1 of the present embodiment has an elongated cylindrical shape with an outer diameter of 5 cm and a length of 1 m, and the gap 5A between the ground electrode 3 and the dielectric 2A shown in FIG. 3 is about 10 mm. It was. Therefore, in the manufacturing process described above, the thickness of the semi-molded body 9 is increased by 25% of the gap 5A, and the thickness when contracted is adjusted to match the gap 5A. Moreover, since firing is performed with the molds 10 and 12 sandwiched from both sides, the outer peripheral surface and inner peripheral surface of the base 9 are defined by the installation surface 11 and the pressing surface 12, and the inner peripheral surface of the ground electrode 3 over the entire axial direction. And the outer peripheral surface of the dielectric 2A. Since shrinkage is also taken into consideration for the circumferential length, the shape of the substrate 9 substantially matches the shape of the discharge space 5 divided into two in the circumferential direction. Thus, the suction plate 6A formed while maintaining the shape of the base body 9 does not require post-processing such as cutting, and is installed so as to fill the gap 5A of the discharge space 5, so that the cylindrical suction body 6 can be easily attached. Can be formed.

Furthermore, since the cross-sectional shape perpendicular to the axial direction of the adsorbent 6 is circular, the flat plate on which the ceramic slurry is uniformly attached is curved with the same curvature, and it is easy to form a uniform communication space in the circumferential direction. become. That is, since the cross-sectional shape perpendicular to the axial direction of the adsorbent 6 is formed in a substantially circular shape, a homogeneous communication space is formed in the circumferential direction, and the discharge reactor 1 with high reaction efficiency can be obtained.
Moreover, since the adsorbent 6 is divided in the circumferential direction, the base 9 has a shape tapered in the opening direction. Therefore, an excessive force is not applied when the base 9 is taken out of the molds 10 and 11, and the yield is improved. Moreover, the freedom degree of the installation direction of the adsorption body 6 in the discharge reactor 1 increases, and working efficiency improves. That is, since the adsorbent 6 is divided in the circumferential direction, the yield is improved and the working efficiency is improved.

In the present embodiment, the insulating dielectric 2A is provided around the conductive high-voltage electrode 2, but the dielectric 2A may be omitted.
Further, the electrodes 2 and 3 can be formed into a tube shape by joining plate materials. For example, when the ground electrode 3 is formed by connecting a punching metal having a predetermined width in which holes are regularly arranged and a solid plate material in the circumferential direction, the portions corresponding to the punching metal are used as the processing gas supply port 3A and the gas exhaust port 3B. Can be used.
Further, in the regeneration process, the replacement gas supply port 4A is provided so as to increase the oxygen concentration in the discharge space 5 in order to suppress the generation of nitrogen oxides, but this is not essential for the regeneration process and is omitted. Is also possible.

On the other hand, the manufacturing method used in this embodiment can be applied to other than the circular shape. For example, when the discharge reactor is rectangular, the U-shaped adsorption plate 16A is manufactured by bending the flat plate so as to have a bent shape as shown in FIG. 9 in accordance with the shape of the discharge space. It is also possible to form the adsorbent 16 having a substantially rectangular cross-sectional shape in the direction. In this case, since the outer shape of the discharge reactor can be formed in a rectangular shape, it is easy to reduce the installation area when a large number of discharge reactors are used in a bundle. That is, when the adsorbent 16 is formed in a substantially rectangular cross section perpendicular to the axial direction, a discharge reactor having a small installation area can be obtained.

Embodiment 2. FIG.
11 is a cross-sectional view of the discharge reactor 1 according to the present embodiment (corresponding to a portion cut along line III-III in FIG. 1), and FIG. 12 is a vertical cross-sectional view (a portion cut along line VI-VI in FIG. 2). Equivalent). The adsorbent 26 includes an inner first layer 27 and an outer second layer 28 which are divided into two in the thickness direction. The first layer 27 is formed by arranging two semi-cylindrical suction plates 27A in the circumferential direction and five rows in the axial direction. The second layer 28 is formed by arranging two semi-cylindrical suction plates 28A in the circumferential direction and four rows in the axial direction at an angle of 90 degrees in the circumferential direction with respect to the first layer. The suction plate 27A has an inner diameter that matches the outer diameter of the dielectric 2A, a thickness of 5 mm that is half the gap 5A, a length of 20 cm, and the suction plate 28A has an outer diameter that matches the inner diameter of the ground electrode 3 and is thick. It is 5 mm long and 25 cm long. Thus, the adsorbent 26 is divided in the thickness direction, the circumferential direction, and the axial direction, but is formed in a cylindrical shape having a length of 1 m and a gap of 10 mm, similar to the adsorbent 6 of the first embodiment.

Next, the operation will be described.
In the gas processing step, when air is supplied from the gas supply port 3A, the adsorbent 26 flows in the circumferential direction and is discharged from the gas exhaust port 3B. At this time, the air is not affected by the division of the adsorbent body 26 and flows in the communication space of the adsorbent body 26 covered with the adsorbing material as in the first embodiment, and the VOC component contained in the air flows to the adsorbent body 26. Adsorbed and removed, clean air containing no VOC comes out from the gas exhaust port 3B.

Subsequently, the supply of air from the processing gas supply port 3A is stopped, and the replacement with oxygen is performed in the same manner as in the first embodiment to perform the discharge process. As a result, the adsorbent 26 is regenerated and returns to a state where VOC can be adsorbed and removed.

In the regeneration processing step, if there is a space directly connecting the high-voltage electrode 2 and the ground electrode 3 in the adsorbent 26, a spatial discharge occurs there. In the present embodiment, the first layer 27 of the adsorbent 26 has a joint 27B running in the axial direction and a joint 27C running in the circumferential direction, and the second layer 28 has a joint 28B running in the axial direction and a joint 28C running in the circumferential direction. . However, since the split position in the circumferential direction of the first layer 27 on the inner side and the split position in the circumferential direction of the second layer 28 on the outer side are changed by 90 degrees, the positions of the joints 27B and 28B running in the axial direction are installed. The high voltage electrode 2 and the ground electrode 3 are not directly connected by the joints 27B and 28B running in the axial direction. Also, in the axial direction, since the number of divisions of the first layer 27 and the second layer 28 is changed by the suction plates 27A and 28A having different lengths, the positions of the seams 27C and 28C running in the circumferential direction are also shifted, and the high voltage electrode 2 and the ground electrode 3 are not directly connected by the joints 27C and 28C running in the circumferential direction. Therefore, useless space discharge that does not contribute to the reaction along the seam of the adsorbent 26 is suppressed, and a decrease in discharge efficiency can be prevented. That is, since the adsorbents 26 divided in the thickness direction are arranged by shifting the positions of the seams in the circumferential direction or the axial direction of the layers 27 and 28, space discharge can be prevented and discharge treatment can be performed efficiently.

Further, in the discharge reactor 1, creeping discharge occurs at both end portions in the axial direction, so that both end portions become dead spaces. For this reason, efficiency can be improved by lengthening an axial length and making dead space relatively small. However, when the length of the suction plate is increased, the yield is reduced and the cost is increased. Therefore, by dividing the adsorbent 26 in the axial direction as in the present embodiment, the dimensions of the adsorbing plates 27A and 28A can be made shorter than the axial length of the discharge reactor 1, thereby improving the yield. . Moreover, since the layers 27 and 28 are divided in the thickness direction as described above and the dividing positions of the layers 27 and 28 are shifted, the discharge along the joints (27B, 28B, 27C, 28C) can be suppressed and high reaction efficiency can be maintained.

In the above embodiment, the seam position is shifted by changing the axial length of the suction plate 27A of the first layer 27 and the suction plate 28A of the second layer 28 or by changing the installation angle in the circumferential direction. However, the seam position can be shifted by other methods. For example, by curving a parallelogram flat plate and forming the cut surface of the suction plate obliquely, the seam angle of adjacent layers can be changed and the seam position can be shifted.

Moreover, by dividing the adsorbent 26 in the thickness direction as described above, a thin synthetic resin foam flat plate can be used. When the plate thickness is reduced, handling such as impregnation, molding and firing of ceramic slurry and adsorbent becomes easy and dimensional accuracy is improved. Further, homogenization in the thickness direction is facilitated, for example, the difference in density between the inner peripheral portion and the outer peripheral portion becomes smaller when the flat plate to which the ceramic slurry is attached is curved. In addition, by changing the number of divisions, it is possible to cope with several types of gap discharge reactors even if flat plate materials having the same thickness are used, and it becomes easy to reduce the manufacturing cost. That is, since the adsorbent 26 is divided in the thickness direction, the adsorbent 26 can be manufactured with high dimensional accuracy and low cost.

Embodiment 3 FIG.
FIG. 13 is a cross-sectional view (corresponding to a portion cut along line III-III in FIG. 1) of the discharge reactor 31 of the present embodiment. The discharge reactor 31 is formed in the shape of an elongated rectangular cylinder, and is provided around the high-voltage electrode 32A, and a SUS rectangular high-voltage electrode 32A provided with a dielectric 32B made of a rectangular glass tube in close contact therewith. The SUS rectangular ground electrode 33 is provided. A rectangular discharge space 35 formed between the two electrodes 32A and 33 is formed by bending a flat synthetic resin foam having ceramic slurry attached thereto, and is formed from a three-dimensional skeleton structure ceramic porous body having a communication space inside. A rectangular cylindrical adsorbent 36 is provided. The adsorbent 36 is also formed of a first layer 37 and a second layer 38 that are divided into two in the thickness direction. The layers 37 and 38 are formed using suction plates 37A and 38A having a U-shaped cross section.

Next, the operation will be described.
In the gas processing step, when air is supplied from the gas supply port 33A, the adsorbent 36 is divided into upper and lower parts and discharged from the gas exhaust port 33B. At this time, the air flows in the communication space of the adsorbent 36 coated with the adsorbent material as in the second embodiment, although the flow velocity differs between the corner portion and the straight portion, and the VOC component is adsorbed by the adsorbent 36. After being removed, clean air containing no VOC comes out from the gas exhaust port 33B.

Subsequently, oxygen is supplied in the same manner as in the second embodiment, replacement with oxygen is performed, and discharge treatment is performed. Here, a slight difference in current density occurs between the corner portion and the straight portion, but the adsorbent 36 is regenerated and returns to a state in which VOC can be adsorbed and removed.

Also in the present embodiment, as in the second embodiment, the division position in the circumferential direction of the first layer 37 and the division position in the circumferential direction of the second layer 38 are shifted by 90 degrees, and thus the axial direction runs. The seams 37B and 38B are separated and do not overlap. Therefore, there is no connection between the high-voltage electrode 32 and the ground electrode 33 by a seam that runs directly in the axial direction, and the spatial discharge directly connecting the electrodes 32 and 33 is suppressed even in the above-described regeneration processing step, and the discharge efficiency is improved. improves.

FIG. 14 is a cross-sectional view (corresponding to a portion cut along line III-III in FIG. 1) of a discharge reactor 31 showing a modification of the third embodiment. In this modification, the second layer 38 of the adsorbent 36 is formed by using an adsorbing plate 38C having different left and right sides. Accordingly, the positions of the joints 37B and 38D running in the axial direction can be shifted without changing the dividing positions in the circumferential direction of the first layer 37 and the second layer 38. Therefore, as in the third embodiment, the spatial discharge directly connecting the electrodes 32 and 33 is suppressed, and the discharge efficiency is improved. In this case, there is a restriction in the loading direction of the adsorbent body 36, and even when it is difficult to shift the circumferential division position by 90 degrees, it is possible to prevent the division positions from being shifted and the seams from overlapping.

Embodiment 4 FIG.
15 is a cross-sectional view (corresponding to a section cut along the line III-III in FIG. 1) of the discharge reactor 51 of the present embodiment (the appearance is the same as FIG. 1 of the first embodiment), and FIG. 16 is a vertical cross-sectional view. (Corresponding to the portion cut along the VI-VI line in FIG. 2). In the present embodiment, the same one as that used in the discharge reactor 1 of the first embodiment except for the ground electrode 53 and the adsorbent 56 was used. The adsorbent 56 is formed by arranging a total of four semi-cylindrical adsorbing plates 56A in the circumferential direction and in the axial direction, and a seam 56B running in the axial direction and a seam 56C running in the circumferential direction are generated. As a portion corresponding to the seam 56B of the ground electrode 53, a conductive protrusion 60A is provided in the circumferential central portion of the gas supply port 53A and the gas discharge port 53B, and this protrusion 60A is provided in the seam. 56B is fitted. In addition, as a portion corresponding to the seam 56C of the ground electrode 53, a conductive protrusion 60B is provided in the central portion in the axial direction over the entire circumference, and the protrusion 60B is fitted to the seam 56C.

Next, the operation will be described.
In the gas processing step, when air is supplied from the gas supply port 53A, the adsorbent 56 flows in the circumferential direction and is discharged from the gas exhaust port 53B. At this time, the air flows in the communication space of the adsorbent 56 covered with the adsorbing material, similarly to the first embodiment, without being obstructed by the protrusion 60A, and the VOC component contained in the air flows to the adsorbent 56. Adsorbed and removed, clean air containing no VOC comes out from the gas exhaust port 53B.

Subsequently, the supply of air from the processing gas supply port 53A is stopped, and the replacement with oxygen is performed in the same manner as in the first embodiment to perform the discharge process. As a result, the adsorbent 56 is regenerated and returns to a state where the VOC can be adsorbed and removed.

In the above-described regeneration treatment step, in the discharge reactor 51 of the present embodiment, since the joints 56B and 56C are directly connected between the high voltage electrode 2 and the ground electrode 53, space discharge occurs at the joints 56B and 56C. However, since the conductive projection 60A provided on the ground electrode 53 is fitted to the joint 56B and the projection 60B is fitted to the joint 56C, the space discharge is not from the inner peripheral surface of the ground electrode 53 but the projections 60A and 60B. It originates from the tip part. For this reason, the inter-electrode distances 55B and 55C where the space discharge occurs are shorter than the gap 55A, and the voltage required for the space discharge is reduced.

When the voltage required for the space discharge is reduced, the power consumed by the space discharge is reduced, and the discharge efficiency can be prevented from being lowered. That is, since the projections 60A and 60B fitted to the joints 56B and 56C of the adsorbent 56 are provided on the ground electrode 53, power loss due to space discharge can be reduced and reaction efficiency can be improved. The protrusions 60A and 60B may be provided on at least one of the electrodes, and may be provided on the high voltage electrode 2 side or on both the electrodes 2 and 53.

Embodiment 5 FIG.
In the present embodiment, 0.3% by weight of silver, which is a catalyst, is supported on the adsorbent 6 used in the first embodiment to form the adsorbent 6 having a catalytic function, and is installed in the discharge reactor 1. .

The VOC decomposition rate during the discharge reaction in the present embodiment was measured.
Air containing 10 ppm of toluene as a processing gas was supplied into the discharge space 5 at a flow rate of 1 m / s from the processing gas supply port 3A for 15 minutes, and a certain amount of toluene was adsorbed on the adsorbent 6. Thereafter, oxygen gas is supplied from the replacement gas supply port 4A, the inside of the discharge reactor 1 is replaced with oxygen, and a high voltage is applied between the high voltage electrode 2 and the ground electrode 3 to generate a discharge. The adsorbed toluene was decomposed. The temperature of the adsorbent 6 was kept at 100 ° C., and the toluene decomposition rate after performing the discharge treatment for 3 minutes was measured. As a comparative example, even when the adsorbent 6 not carrying the catalyst in Embodiment 1 was used, the measurement was performed under the same conditions, and the toluene decomposition rates were compared.

As a result, when the adsorbent 6 carrying 0.3% of silver was used, the toluene decomposition efficiency was improved by 10% or more compared to the case of using the adsorbent 6 not carrying the catalyst. This is because silver serving as a catalyst is applied on a random network having a three-dimensional skeleton structure having an internal communication space of the adsorbent 6, thus forming a uniform reaction space and effectively promoting a decomposition reaction by catalysis. It was because it was done. In other words, adsorption consisting of a three-dimensional skeletal ceramic porous body having a communication space inside a substrate obtained by coating a substrate obtained by curving and molding a flat synthetic resin foam to which ceramic slurry is adhered and then firing. Since the catalyst is supported on the body 6, the reaction efficiency is improved. In addition, since the amount of catalyst supported was very small in volume for the adsorbent 6, there was no change in pressure loss, and there was no change in the adsorption rate.

Embodiment 6 FIG.
FIG. 17 is a system block diagram of the gas processing apparatus 70 of the present embodiment. The gas processing device 70 has a communication space in the interior in which a base obtained by curving and molding a flat synthetic resin foam to which the ceramic slurry is attached according to each of the above embodiments is coated with an adsorbent material. A plurality of discharge reactors 1 using an adsorbent 6 made of a porous ceramic body having a three-dimensional framework structure is provided. A high voltage generator 71 having a voltage switching function is connected to the high voltage electrode 2 and the ground electrode 3 of each discharge reactor 1, and a high voltage can be applied between the electrodes. Further, a gas supply device 72 is connected to the processing gas supply port 3A of each discharge reactor 1. The gas supply device 72 includes a flow rate adjusting unit 72A and an exhaust fan 72B that are separately installed. The processing gas is connected by piping so as to be introduced into the processing gas supply port 3A of each discharge reactor 1 through the filter 73 and the flow rate adjusting valve 72A. An exhaust fan 72B is connected to each gas discharge port 3B, and the outlet is opened to the atmosphere. A replacement gas supply device 74 is connected to the replacement gas supply port 4 </ b> A of each discharge reactor 1.

Next, the operation will be described.
When the exhaust fan 72B is driven, the processing gas is drawn into the discharge reactor 1 from the processing gas supply port 3A through the filter 73 and the flow rate adjusting valve 72A by the suction force. The gas flow rate flowing to each discharge reactor 1 is adjusted by a flow rate adjusting valve 72A. The introduced gas passes through the communication space of the adsorbent 6 installed in the discharge space 5, adsorbs and removes the VOC component, passes through the discharge port 3B, and is discharged from the exhaust fan 72B to the atmosphere.

If the above processing is continued, the adsorbed VOC components accumulate in the adsorbent 6. Therefore, before the accumulated amount of the VOC component exceeds a certain amount, the exhaust fan 72B is stopped to stop the supply of the processing gas, and the regeneration process by the discharge reaction of the adsorbent 6 is performed. Before the discharge reaction, oxygen gas is supplied to each discharge reaction tube 1 from the replacement gas supply device 74 through the replacement gas supply port 4A, and the air is replaced until the oxygen concentration in each discharge reactor 1 becomes 50%. Next, a high voltage generator 71 applies an alternating high voltage of several kV between the ground electrode 3 and the high voltage electrode 2 to generate discharge plasma in the discharge space 5. As a result, the VOC component is desorbed from the adsorbent 6, reacts with oxygen, and is decomposed into water and carbon dioxide. As a result, the VOC component adsorbed on the adsorbent 6 is removed, and the gas processing can be resumed.

During the gas treatment step, the discharge reactor 1 has a communication space inside the substrate obtained by curving and molding a flat synthetic resin foam to which ceramic slurry is adhered and then baking the substrate. Since the adsorbent 6 made of the three-dimensional skeleton structure ceramic porous body is used, the pressure loss is reduced, the electric power required for the exhaust fan 72B is reduced, and the power can be saved. Furthermore, since the adsorbent is carried in the uniform communication space, the entire adsorbent 6 can be functioned effectively. Therefore, the adsorption efficiency is increased, and a large amount of gas can be processed when an apparatus of the same scale is used. In particular, when the discharge reactor shown in Embodiments 2 to 5 is used, the discharge reaction efficiency is improved, and the load on the high voltage generator 71 is effectively reduced.

In addition, by providing a discharge reaction vessel (not shown) capable of storing a plurality of discharge reactors 1 and storing the plurality of discharge reactors 1 together in the discharge reaction vessel, temperature management becomes easy. It is also possible to divide the discharge reactor 1 into a plurality of groups and perform intermittent operation while switching between gas treatment and regeneration treatment. Further, in the present embodiment, substitution with oxygen is performed to prevent generation of nitrogen oxides during the discharge reaction, but this is not essential for regeneration of the adsorbent 6. If the generation of nitrogen oxides in the discharge reactor 1 is allowed, such as by providing a separate nitrogen oxide removal device, the replacement gas supply device 73 can be omitted. The form of the gas supply device 72 may take any form as long as the process gas can be supplied to the discharge reactor 1. The filter 73 is also provided to separate and remove highly adhesive substances such as paint and oil, but it is not an essential element and can be omitted.

In each of the above embodiments, as a material for forming the adsorbent 6 made of a three-dimensional skeleton structure ceramic porous body having an internal communication space, a soft polyurethane foam flat plate having no cell membrane is used as the synthetic resin foam. is doing. For the production of the adsorbent 6, the structure without the cell membrane is suitable, but a plate-like synthetic resin foam having a three-dimensional skeleton structure having an internal communication space can be used even with a cell membrane. .
The ceramic slurry is mainly composed of alumina, but mullite, titania, zircon, zirconia, spinel, cordierite, silicon carbide, silicon nitride and the like can also be used. In addition, any ceramic material can be used as long as the material can obtain a strength sufficient to maintain a three-dimensional skeleton structure by sintering.
The adsorbing material is not limited to hydrophobic zeolite, but may be mesoporous silicate, dealuminated faujasite, high silica pentasil zeolite, silica gel, sepiolite, or other materials.

It is a front view of the discharge reactor which shows Embodiment 1 of this invention. It is a side view of the discharge reactor which shows Embodiment 1 of this invention. It is sectional drawing of the discharge reactor which shows Embodiment 1 of this invention. It is a longitudinal cross-sectional view of the discharge reactor which shows Embodiment 1 of this invention. It is a perspective view of the shaping | molding die used at the manufacturing process of Embodiment 1 of this invention. It is a perspective view of the shaping | molding die used at the manufacturing process of Embodiment 1 of this invention. It is a perspective view which shows the manufacturing process of Embodiment 1 of this invention. It is a figure which shows the manufacturing process of Embodiment 1 of this invention. It is a figure which shows the manufacturing process of Embodiment 1 of this invention. It is sectional drawing which shows the molded object which shows the modification of Embodiment 1 of this invention. It is sectional drawing of the discharge reactor which shows Embodiment 2 of this invention. It is a longitudinal cross-sectional view of the discharge reactor which shows Embodiment 2 of this invention. It is sectional drawing of the discharge reactor which shows Embodiment 3 of this invention. It is sectional drawing of the discharge reactor which shows the modification of Embodiment 3 of this invention. It is sectional drawing of the discharge reactor which shows Embodiment 4 of this invention. It is a longitudinal cross-sectional view of the discharge reactor which shows Embodiment 4 of this invention. It is a system block diagram of the gas treatment apparatus which shows Embodiment 6 of this invention.

Explanation of symbols

1, 31, 51 discharge reactor, 2 high voltage electrode, 2A dielectric,
3 Ground electrode, 3A Process gas supply port, 3B Gas discharge port,
5 discharge space, 5A gap, 6, 16, 26, 36, 56 adsorbent,
6A, 16A, 27A, 28A, 37A, 38A, 38C, 56A Adsorption plate,
27, 28, 37, 38 layers,
27B, 27C, 28B, 28C, 37B, 37C, 38B, 38D, 56B
60A, 60B protrusion,
70 gas processing device, 71 high voltage generator, 72 gas supply device,
900 base

Claims (8)

A first electrode, a second electrode provided around the first electrode, and a flat plate provided in a discharge space formed between the first electrode and the second electrode, to which ceramic slurry is adhered. A cylindrical adsorbent comprising a three-dimensional skeleton structure ceramic porous body having a communication space inside is coated with a base obtained by calcining and molding a synthetic resin foam and then covered with an adsorbent material. Discharge reactor. The discharge reactor according to claim 1, wherein the adsorbent has a cross-sectional shape perpendicular to the axial direction formed in a substantially circular or substantially rectangular shape. The discharge reactor according to claim 1, wherein the adsorbent is divided in a circumferential direction. The discharge reactor according to claim 1, wherein the adsorbent is divided in a thickness direction. 5. The discharge reactor according to claim 4, wherein the adsorbent is disposed by shifting the circumferential or axial joint positions of the respective layers divided in the thickness direction. 2. The discharge reactor according to claim 1, wherein a protrusion that fits to a joint of the adsorbent is provided on at least one of the first electrode and the second electrode. The discharge reactor according to claim 1, wherein the adsorbent supports a catalyst. A discharge reactor according to any one of claims 1 to 7, a high voltage generator for applying a voltage between electrodes of the discharge reactor, and a gas supply device for supplying a gas to be processed to the discharge reactor. A gas treatment apparatus characterized by the above.

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