JP3684466B2 - Adsorbent module - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for removing a nitrogen dioxide (NO ₂ ) adsorbent. More specifically, the present invention relates to a low concentration nitrogen oxide (NOx) contained in a ventilation gas from a road tunnel or a closed space, that is, The present invention relates to an adsorbent module filled in a removal apparatus in a removal apparatus that removes harmful substances NO ₂ having an environmental standard value set from an object gas containing nitrogen oxide (NO) and nitrogen dioxide (NO ₂ ) using an adsorbent. Is.
[0002]
[Prior art]
As a method for removing low-concentration nitrogen oxides, particularly NO ₂ , contained in ventilation gas that exits from road tunnels and underground closed spaces, the present inventors previously proposed a method for adsorption removal with a nitrogen dioxide adsorbent ( (Japanese Patent Application Nos. 9-16334, 9-214764, 9-214768, 9-238768, and 9-246270).
[0003]
Further, in Japanese Patent Application No. 10-130198 “Regeneration Method of Nitrogen Dioxide Adsorbent”, the nitrogen dioxide adsorbent is modularized, this adsorbent module is filled in an adsorption removal device, and after performing an adsorption operation for a predetermined time, the adsorption is performed. It was proposed that the adsorbent be removed from the adsorption removal device together with the module, transported to the recycling plant, and then regenerated, and then the regenerated adsorbent module be filled in the adsorption removal device again and used repeatedly.
[0004]
[Problems to be solved by the invention]
Usually, when a small amount of adsorbent is charged in an adsorber (reactor), it can be filled by a relatively simple operation as described below.
[0005]
{Circle around (1)} The adsorbent honeycomb (21) is cut out to a predetermined size and inserted into the adsorber (22) from its inlet (see FIG. 1).
[0006]
{Circle around (2)} Several adsorbent honeycombs (21) cut out to a predetermined size are combined vertically and horizontally, and the lid (23) is opened and inserted into the adsorber. At this time, a sheet-like or string-like sealing material (24) is inserted into the gap between the adsorbent honeycomb and the adsorber as necessary to prevent gas from blowing through (see FIG. 2).
[0007]
When a large amount of gas is processed and a plurality of adsorbent modules are filled in the processing gas passage cross section, gaps between adsorbent modules and between adsorbent modules and adsorbers are processed. It must be sealed in some way to prevent gas from blowing through.
[0008]
In order to fill the adsorber with the adsorbent module obtained by modularizing the adsorbent, the adsorbent module itself must be completely sealed. That is, it is necessary to seal so that gas does not blow through the adsorbents that are modularized and through the gap between the adsorbent and the module outer frame.
[0009]
The gas blown here means that the gas passing through the gap does not touch the adsorbent, and nitrogen dioxide (NO ₂ ) blows through without being removed by adsorption.
[0010]
In the case of the honeycomb adsorbent, the processing gas passes through the eyes of the honeycomb (in the channel). At this time, the adsorbed substances in the process gas during the passage (eg: NO ₂₎ is adsorbed by the adsorbent diffuse moved to the adsorbent surface, purge gas gas passing through the adsorbent in which NO ₂ is adsorbed and removed become.
[0011]
Further, in the nitrogen dioxide removing device proposed by the present inventors in the above Japanese Patent Application No. 10-130198, the adsorbent module that has finished predetermined adsorption (assuming adsorption for about one year) in the removing device is adsorbed. Extracted from the vessel and sent to a recycling plant to regenerate the adsorbent.
[0012]
The adsorbent module is washed with water at an adsorbent regeneration plant, and NO ₂ adsorbed and immobilized as nitrate or nitrite on the adsorbent is washed away. At this time, since a part of the active substance carried on the adsorbent is also washed out, the adsorbent module washed with water is immersed in a reactivation bath containing a chemical solution to re-support the active substance, and then dried. Regenerate the adsorbent. Prior to the water washing treatment of the adsorbent module, the adsorbent module is placed in a heating furnace and heated to 200 to 500 ° C., thereby desorbing desorbable nitrogen oxides and simultaneously adsorbed on the adsorbent. Mist may be burned (see FIG. 3).
[0013]
When the adsorbent regeneration process is performed for each adsorbent module, the following points must be noted.
[0014]
(1) A module is formed so that gas does not blow through the adsorbent module.
[0015]
(2) The module structure is such that no thermal distortion occurs during the heat treatment.
[0016]
{Circle around (3)} The gas flow direction of the honeycomb adsorbent is the vertical direction at the time of water washing and chemical immersion, so that the module structure is such that the adsorbent does not fall off during water washing and chemical immersion.
[0017]
(4) Use chemical-resistant materials for the wetted parts of the module so that no significant corrosion or the like occurs during washing with water or chemicals.
[0018]
On the other hand, when the adsorbent regeneration process is not performed for each module, and the module is disassembled and performed for each block, the following points must be noted.
[0019]
{Circle around (1)} Modularize the gas so that gas does not blow through the adsorbent block and the adsorbent module.
[0020]
(2) A block structure in which thermal distortion does not occur during heat treatment.
[0021]
{Circle around (3)} Since the gas flow direction of the honeycomb adsorbent is the vertical direction during water washing and chemical immersion, a block structure is adopted so that the adsorbent does not fall off during water washing and chemical immersion.
[0022]
(4) Use a chemical-resistant material for the wetted part of the block so as not to cause significant corrosion or the like even when washed with water or immersed in a chemical solution.
[0023]
[Means for Solving the Problems]
An adsorbent module according to the present invention includes an adsorbent module comprising a rectangular module outer frame as viewed in the gas flow direction and a plurality of adsorbent blocks grouped by the outer frame. An L-shaped outer frame half that is bent into a mold and an inverted L-shaped outer frame half are arranged so as to face each other.
[0024]
It is preferable to arrange reinforcing grids at the inlet, outlet and / or intermediate width of the module outer frame.
[0025]
It is preferable to fix the ends of the pair of outer frame halves with each other and to fix the pair of outer frame halves and the reinforcing grid by non-welding fixing means. Examples of non-welding fixing means include rivets, bolts / nuts, screws, and the like.
[0026]
The module outer frame and the reinforcing grid are preferably made of steel.
[0027]
It is also preferable to provide a flange inwardly at the front and rear edges of the module outer frame in the gas flow direction.
[0028]
First, in FIG. 4 (a), an adsorbent honeycomb having a length (A) of 0.15 m, a width (B) of 0.15 m, and a length (C) of 0.4 m is prepared, as shown in FIG. 4 (b). Nine adsorbents (1) are arranged in three rows and stacked in three rows, and these adsorbents (1) are accommodated inside a stainless steel steel square storage frame (2). Thus, an adsorbent block having a length (A) of 0.45 m, a width (B) of 0.45 m, and a length (C) of 0.4 m is obtained. Although not shown in the figure, glass paper or the like made of nonflammable fibers is used as a gas seal material or cushion material between the adsorbents (1) and between the adsorbent (1) and the storage frame (2). May be included. Then, as shown in FIG. 4 (c), six adsorbent blocks (3) are stacked in two rows and three rows, and these adsorbent blocks (3) are arranged in a rectangular tube-like storage frame made of steel plate, that is, an outer frame. By accommodating the inside of (4), an adsorbent module (5) having a length (A) of 1.4 m, a width (B) of 0.9 m, and a length (C) of 0.5 m is obtained. In this case as well, although not shown, glass paper or the like made of noncombustible fibers is used as a gas sealing material between the adsorbent blocks (3) and between the adsorbent blocks (3) and the outer frame (4). Or you may swallow it as a cushioning material.
[0029]
FIGS. 5 (a) and 5 (b) show an example of a nitrogen dioxide adsorption / removal device installed in an underground space adjacent to a road tunnel. The adsorption / removal device (10) includes a reactor (11) in which ventilation gas from a road tunnel flows horizontally, and an electric dust collector (11A) installed on the ventilation gas inlet (11A) side in the reactor (11). 12) and a plurality of adsorbent modules (5) installed on the ventilation gas outlet (11B) side in the reactor (11). The plurality of adsorbent modules (5) are arranged in a zigzag shape as viewed from the plane so as to cross the inside of the reactor (11). Each of the straight sections in a zigzag arrangement is filled with a shelf (13) consisting of four-tiered shelf floors (17), and 36 adsorbent modules (5) arranged in three rows vertically and horizontally in each row. Consists of.
[0030]
The shelves (13) containing a plurality of adsorbent modules (5) are arranged in a zigzag shape because the linear velocity of the gas passing through the adsorbent honeycomb in the adsorbent module (5) is reduced to reduce the pressure loss. This is a contrivance for lowering, and when there is a margin in the allowable pressure loss, it is not always necessary to arrange in a zigzag shape, and it may be arranged so that the equipment volume becomes more compact.
[0031]
The nitrogen dioxide adsorbent is carried in, for example, as shown in FIG. First, the adsorbent module (5) manufactured and modularized at the adsorbent manufacturing plant is transported to the installation site of the nitrogen dioxide adsorption removal device (10) by a truck or the like, and then the crane truck is transported from the ground inlet (14). (15) Alternatively, use a gate crane or the like to lower it onto the electric lifter (16) placed on the floor of the underground space. Next, the adsorbent module (5) is transported to the side of the reactor (11) by the electric lifter (16), and the adsorbent module (5) is lifted to a predetermined height and the module storage chamber (in the reactor (11) ( Fill in 13). 6 shows the case where the adsorbent module (5) is lowered to the electric lifter (16). However, the adsorbent module is mounted on an automatic traveling carriage that runs on rails arranged along the side of the reactor. After loading and transporting to the reactor side, the adsorbent module is raised to the predetermined height together with the carriage, and then the adsorbent module is moved by the automatic traveling carriage that runs on the rail placed in the module storage chamber in the reactor. It is also possible to adopt an automatic carry-in system for carrying and filling the predetermined position.
[0032]
The following matters are required for the adsorbent module used in the nitrogen dioxide removing apparatus proposed by the present inventors.
[0033]
A collection of several adsorbents (for example, an adsorbent block in which a plurality of adsorbents are accommodated in a rectangular tube storage frame may be collected) and collected outside the adsorbent module divided into two or more Surround it with a frame and make it modular. At this time, take measures to prevent gas from blowing through the adsorbent or a collection of adsorbents, for example, the gap between adsorbent blocks and the gap between the adsorbent or adsorbent collection and the module outer frame. Necessary.
[0034]
Further, in order to secure the strength of the adsorbent module, it is necessary to reinforce the adsorbent module with a reinforcing tension, such as a grid, as necessary.
[0035]
Further, when the divided module outer frame is integrated as an adsorbent module, a structure not based on welding, for example, bolt / nut tightening, riveting, pin or hinge fixing, etc. is adopted. In this way, even if the adsorbent module is disassembled, disassembly is easy, and the disassembled module outer frame can be reused even when modularized again, and heating during adsorbent regeneration In processing, thermal distortion does not occur, so dimensional accuracy is good.
[0036]
Next, when washing the adsorbent with water or chemicals during regeneration, when adsorbing the entire adsorbent module with water or chemicals, the adsorbent honeycomb eye direction (the direction in which the gas flows) is vertical. The module is moved so that the adsorbent module is immersed in the washing tank or the dipping tank or pulled out of the washing tank or the dipping tank. Therefore, it is necessary to take measures to prevent the adsorbent from falling off due to the vertical movement of the adsorbent module. For example, even if the adsorbent is dropped by inserting a grid or the like, the grid can prevent the adsorbent from dropping off. To do. Furthermore, since the liquid after washing shows acidity and the immersion liquid is an aqueous solution of the active agent, it is necessary to use a chemical-resistant material for the liquid contact part of the adsorbent module.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be specifically described based on examples.
[0038]
Example 1
FIG. 7 shows an embodiment in which a plurality of adsorbents are collectively modularized.
[0039]
In FIG. 7, the adsorbent module is composed of a vertically long rectangular module outer frame when viewed in the gas flow direction, and a plurality of adsorbent blocks grouped by the outer frame. The module outer frame is configured by arranging an L-shaped outer frame half (31) formed by bending a belt plate into an L shape and an inverted L-shaped outer frame half (36) in an opposing manner.
[0040]
A center grid (32) is arranged in the center of the width of the L-shaped outer frame half (31), and the bottom (horizontal portion) and side (vertical) of the L-shaped outer frame half (31) are arranged by rivets around the grid. Part) was fixed so that it would be a right angle (90 °) (see FIGS. 7A and 7B).
[0041]
A plurality of adsorbent (35) blocks are stacked on the bottom of the L-shaped outer frame half (31) on both the front and rear sides in the gas flow direction with the central grid (32) interposed therebetween (FIGS. 7 (c) (d) reference). At this time, the sealing material is squeezed between the adsorbent blocks and between the adsorbent block and the module outer frame as necessary.
[0042]
After loading a predetermined number of adsorbent blocks, an inlet grid (33) and an outlet grid (34) are arranged at the processing gas inlet / outlet of the module outer frame, respectively, and the L-shaped outer frame half (31 ) (See FIG. 7 (e)).
[0043]
Finally, the inverted L-shaped outer frame half (36) is connected to the L-shaped outer frame half (31) so as to face each other to form a rectangular tube-shaped module outer frame, and the ends of both halves are riveted together Secure (see Fig. 7 (f)). A plurality of adsorbents are surrounded by a module outer frame to be modularized. Also, if necessary, squeeze the sealant between the adsorbent and the module outer frame to press the adsorbent.
In addition, it is also possible to arrange at least one of the entrance grid and the exit grid without the central grid.
[0044]
Further, in order to prevent deformation of the module outer frame, one corner portion and a corner portion at a diagonal position at the processing gas inlet / outlet portion of the module outer frame are fixed by a turnbuckle (37). It is desirable to fix the remaining corners to the hooks with turnbuckles.
[0045]
Bolts, nuts and screws can be used instead of rivets.
[0046]
An arrangement example of the module outer frame, the adsorbent and the grid is shown in FIG.
[0047]
FIG. 8 (a) shows an example in which an inlet grid (33) and an outlet grid (34) are provided at the inlet / outlet portion of the module outer frame, and an adsorbent (35) is arranged between these grids.
[0048]
FIG. 8 (b) shows an example in which a central grid (32) is provided at the center of the width of the module outer frame, and adsorbents (35) are respectively arranged before and after the central grid.
[0049]
FIG. 8 (c) shows an example in which an inlet grid (33) and an outlet grid (34) are provided at the inlet / outlet portion of the module outer frame, and two rows of adsorbents (35) are arranged between these grids.
[0050]
In FIG. 8 (d), a central grid (32) is provided at the center of the width of the module outer frame, an inlet grid (33) and an outlet grid (34) are provided at the entrance / exit, and an adsorbent (35) is placed between these grids. An example is shown in which two rows of adsorbents (35) are arranged as a whole.
[0051]
Comparative Example 1
In FIG. 9, the module top plate (38), the module bottom plate (39), the module left side plate (40), and the module right side plate (41) are arranged so as to form a vertically long rectangular module outer frame. The example which fixed the edge parts of is shown.
[0052]
In this example, flanges (40a) (41a) are provided on the upper and lower ends of the module left and right side plates (40) and (41), respectively, and the module bottom plate (39) is fixed to each lower end flange with bolts and nuts. 39) and the left and right side plates (40) and (41), attach the grid (32) by fixing the flange around the grid (32) with bolts and nuts, and then sandwich the grid (32) in both the front and rear in the gas flow direction. After loading the adsorbent, finally, the module top plate (38) is fixed to the upper end flange portion of the module left and right side plates (40) (41) and the upper end of the grid with bolts and nuts.
[0053]
In this case, since the flange portions on the upper and lower sides of the module outer frame protrude outward from the module left and right side plates (40) and (41), the adsorbent modules cannot be placed close to each other.
[0054]
Example 2
FIG. 10 shows an example in which the module outer frame has a flange. That is, the module outer frame is configured by arranging an L-shaped outer frame half body (31) formed by bending a belt plate into an L shape and an inverted L-shaped outer frame half body (36) in an opposing manner. A flange (42) is provided inwardly at the front and rear edges of the bodies (31) and (36) in the gas flow direction. As shown in FIG. 11, a downward bent portion (43) is provided at the tip of the horizontal portion of the inverted L-shaped outer frame half (36).
[0055]
When forming the rectangular tube-shaped module outer frame by connecting the inverted L-shaped outer frame half (36) to the L-shaped outer frame half (31) so as to face each other, the vertical part of the L-shaped outer frame half (31) The upper end is arranged in an affixed manner to the downward bent part (43) of the inverted L-shaped outer frame half (36), and a seal tape (44) is pasted in the frame width direction over both, 31) and reverse L-shaped outer frame half (36) are connected.
[0056]
An annular packing (45) is wound around the front and rear surfaces of the flange (42) of the module outer frame in the gas flow direction.
[0057]
FIG. 12 shows a modification in which the L-shaped outer frame half (31) and the inverted L-shaped outer frame half (36) are connected. In this example, a notch (46) having a downward opening is formed at the front end of a front and rear flange (42) provided in the horizontal portion of the inverted L-shaped outer frame half (36). The upper end of the vertical part of the L-shaped outer frame half body (31) is fitted into these notches (46), the seal tape (47) is pasted on this fitting part, and the upper end of the vertical part is attached to the inverted L-shaped outer frame half body (36). Secure with a rivet (48) on the end flange of the horizontal part.
An annular packing (45) is wound around the front and rear surfaces of the flange (42) of the module outer frame in the gas flow direction.
[0058]
Bolts, nuts and screws can be used instead of rivets.
[0059]
Other configurations are the same as those of the first embodiment.
[0060]
In this embodiment, since the module outer frame has a flange, the module outer frame itself is less distorted and stronger. This eliminates the need for a grid for reinforcing the module outer frame. However, a grid may be inserted as necessary to prevent the adsorbent from falling off, such as when the entire module is regenerated.
[0061]
【The invention's effect】
In the adsorbent module of the present invention, the module outer frame is configured by arranging a pair of outer frame halves (31) formed by bending a belt plate in an L shape so as to face each other. There is no large protrusion such as a flange on the side of the frame, and it is possible to install the adsorbent modules with a small space between them, making the adsorber filled with the adsorbent modules compact and the processing gas passage area of the adsorber The (area occupied by the adsorbent module) can be increased with respect to the cross section of the adsorber.
[0062]
Moreover, the module outer frame can be strengthened by arranging the reinforcing grid on the module outer frame.
[0063]
Also, by fixing the ends of the pair of outer frame halves (31) to each other and fixing the pair of outer frame halves (31) and the reinforcing grid by non-welding fixing means, by heat treatment during adsorbent regeneration However, there is no risk of thermal distortion, and module assembly is easy. In addition, even when the adsorbent module is disassembled, the module can be easily disassembled due to the non-welded structure.
[0064]
Furthermore, when the module outer frame and the reinforcing grid are made of stainless steel, when the adsorbent is regenerated, the regenerating process for each adsorbent module can be performed, and the regenerating process can be facilitated.
[0065]
On the other hand, it is possible to regenerate the adsorbent as an adsorbent block without using the adsorbent for the entire adsorption module. In this case, there are the following advantages.
[0066]
Since the regeneration process is performed in units of blocks, the module outer frame, the grid, and the like are not subjected to heat treatment or chemical treatment. Therefore, the module outer frame and the reinforcing grid may be made of ordinary steel instead of expensive materials such as stainless steel. When the adsorbent is put into a rectangular cylindrical storage frame to form a block, only the storage frame may be a thin stainless steel plate.
[0067]
In addition, when the chemical solution is immersed in the entire module, a grid or the like is necessary to prevent the adsorbent from falling off the module outer frame. It is not necessary to provide a grid, and a grid that does not contribute to the reinforcement of the module outer frame can be omitted.
[0068]
Furthermore, by providing flanges (42) inwardly at the front and rear edges of the module outer frame in the gas flow direction, the distortion of the module outer frame itself can be reduced and the strength can be increased.
[Brief description of the drawings]
FIG. 1 (a) is a schematic view showing an example in which an adsorbent is filled in an adsorber. FIG.1 (b) is sectional drawing which follows the bb line in Fig.1 (a).
FIG. 2 (a) is a schematic view showing an example in which an adsorbent is filled in an adsorber. FIG. 2B is a cross-sectional view taken along the line bb in FIG.
FIG. 3 is a flow sheet showing an adsorbent regeneration process.
4 (a) is a perspective view showing an adsorbent honeycomb, FIG. 4 (b) is a perspective view showing an adsorbent block, and FIG. 4 (c) is a perspective view showing an adsorbent module.
5 (a) and 5 (b) are a horizontal sectional view and a vertical sectional view showing a nitrogen dioxide adsorption / removal device installed in an underground space adjacent to a road tunnel.
FIG. 6 is a vertical sectional view showing a state in which the adsorbent is carried into the nitrogen dioxide adsorption / removal device.
7 (a) (b) (c) (d) (e) (f) is a perspective view showing a process of manufacturing the adsorbent module of Example 1. FIG.
FIGS. 8A, 8B, 8C, and 8D are schematic views showing an example of the arrangement of a module outer frame, an adsorbent, and a grid.
FIG. 9 is a front view showing the adsorbent module of Comparative Example 1. FIG.
FIG. 10 is a perspective view showing an adsorbent module according to a second embodiment.
FIGS. 11 (a) and 11 (b) are perspective views showing a connecting portion between an L-shaped outer frame half and an inverted L-shaped outer frame half in the adsorbent module of Example 2. FIGS.
12 (a) and 12 (b) are perspective views showing a modification of the connecting portion between the L-shaped outer frame half and the inverted L-shaped outer frame half in the adsorbent module according to the second embodiment.
[Explanation of symbols]
31: L-shaped outer frame half bodies 32, 33, 34: Grid 35: Adsorbent 36: Reverse L-shaped outer frame half body 42: Flange

Claims (5)

In an adsorbent module comprising a rectangular module outer frame as viewed in the gas flow direction and a plurality of adsorbent blocks gathered by the outer frame,
An adsorbent module, wherein the module outer frame is configured by arranging an L-shaped outer frame half formed by bending a belt plate into an L-shape and an inverted L-shaped outer frame half so as to face each other. The adsorbent module according to claim 1, wherein a reinforcing grid is disposed at an inlet portion, an outlet portion, and / or a width intermediate portion of the module outer frame. The adsorbent module according to claim 1 or 2, wherein the ends of the pair of outer frame halves are fixed to each other and the pair of outer frame halves and the reinforcing grid are fixed by non-welding fixing means. The adsorbent module according to any one of claims 1 to 3, wherein the module outer frame and the reinforcing grid are made of steel. The adsorbent module according to any one of claims 1 to 4, wherein flanges are provided inwardly at front and rear edges of the module outer frame in the gas flow direction.

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