JP2000334267A - Heat storage type waste gas treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely purify VOC and NOx contained in a low temp. waste gas introduced in the large quantity at high heat efficiency and to reduce running cost. SOLUTION: A catalyst layer 6 composed of a NOx occlusion reducing type catalyst is formed in a waste gas treating chamber 3 to face a regenerator 4 of a regenerative heat exchanger 5 communicated therewith. The regenerator 4 is divided into an air feed region 4in, through which an untreated waste gas to be introduced into the waste gas treating chamber 3 is passed, a waste gas region 4out, through which the treated waste gas discharged from the waste gas treating chamber 3 is passed and an a waste gas interrupting region 4s, where the passing of the untreated waste gas and a treated waste gas is interrupted and a reducing gas is supplied, and the VOC and NOx are purified with the catalyst layer 6 in the waste gas treating chamber 3 by continuously introducing the waste gas while switching successively each region (4in, 4out, 4s).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a volatile organic compound (hereinafter referred to as "VOC") and nitrogen oxides (hereinafter referred to as "NOx") contained in exhaust gas discharged from a drying oven for coating and other industrial plants. The present invention relates to a heat storage type exhaust gas treatment apparatus that purifies the exhaust gas and collects and reuses the heat of the treated exhaust gas.

[0002]

2. Description of the Related Art FIG. 5 is an explanatory view showing a conventional exhaust gas treatment apparatus for removing VOC and NOx contained in exhaust gas discharged from an industrial plant. In the exhaust gas treatment device 50, a burner 52, a reducing gas injection nozzle 53, and a catalyst layer 54 of vanadium oxide (V ₂ O ₅ ) or titania (TiO ₂ ) are disposed in the exhaust gas treatment chamber 51 along the flow direction of the exhaust gas. The exhaust gas treatment chamber 51 is arranged in this order.
Low-temperature untreated exhaust gas sent through an exhaust gas introduction duct 55 to the exhaust gas exhaust duct 5
And a heat exchanger 57 for exchanging heat with the high-temperature treated exhaust gas discharged through the heat exchanger 6.

The air is supplied through an exhaust gas introduction duct 55.
After the untreated exhaust gas is preheated in the heat exchanger 57,
A predetermined catalytic reaction temperature is controlled by a burner 52 in the processing chamber 51.
(300-350 ° C.) and introduced into the catalyst layer 54
Then, the VOC in the exhaust gas is burned. This and
At the same time, ammonia gas is
(NH_Three), The NOx contained in the exhaust gas
Nitrogen (N_Two) And water (H_TwoO)
You. Thus, the VOC is burned in the presence of the catalyst.
Together with ammonia (NH _Three) To decompose NOx
And harmless.

[0004]

However, this type of exhaust gas treatment apparatus 50 has a low thermal efficiency of about 50%, which not only increases the fuel cost supplied to the burner 52, but also increases the cost of ammonia (NH _{3) which} is expensive as a reducing gas. ) Has to be used in large quantities, which raises the problem of increased running costs. If a regenerative heat exchanger with high thermal efficiency is used instead of the partition type heat exchanger 57 with low thermal efficiency, the fuel efficiency is improved, so that the running cost can be reduced by that much. _{The same} is required in that ₃ ) is required in large quantities.

In recent years, VOC and NOx contained in exhaust gas have been removed by supplying a small amount of inexpensive reducing gas such as hydrocarbons without using expensive reducing gas such as ammonia (NH ₃ ). NO that can do
A new catalyst called an x storage reduction catalyst has been developed.

This catalyst has a VOC at a predetermined catalyst combustion temperature.
While burning NOx in the exhaust gas in a lean state (oxygen-rich atmosphere) to produce nitrate (NO ₃ ) ⁻
And reducing it to nitrogen (N ₂ ) in a rich state (excessive atmosphere of reducing species) and discharging.

[0007] While the exhaust gas is being supplied, the exhaust gas is in a lean state due to the oxygen contained in the exhaust gas. When the reducing gas such as hydrocarbons is supplied, the exhaust gas becomes a rich state. If they are formed alternately, VOCs contained in the exhaust gas can be burned by the catalyst, and NOx can be stored and reduced.

However, the exhaust gas treatment chamber 51 has a large volume, and a large amount of oxygen is present because untreated exhaust gas containing oxygen is supplied through an exhaust gas introduction duct. When a hydrocarbon is supplied, it is burned by a burner that heats the inside of the exhaust gas treatment chamber 51, changes into water (H ₂ O) and carbon dioxide (CO ₂ ), and does not act as a reducing gas. Occurs. Therefore, in order to reduce running costs, N
Even if an Ox storage reduction catalyst is used and hydrocarbons are supplied as a reducing gas, it is difficult to switch the catalyst layer 54 between the lean state and the rich state, and as a result, the NOx purification process cannot be performed efficiently. There was a problem.

Accordingly, it is a technical object of the present invention to reliably and efficiently purify VOCs and NOx contained in low-temperature exhaust gas introduced in a large amount and to reduce the running cost.

[0010]

In order to solve this problem, the present invention provides an exhaust gas treatment chamber having a catalyst layer for burning volatile organic compounds contained in exhaust gas. In the heat storage type exhaust gas treatment device formed in communication with the exchanger, the catalyst layer is formed facing the heat storage chamber of the heat storage type heat exchanger, and the NOx is formed in an oxygen-excess atmosphere.
a NOx storage-reduction catalyst having a function of storing x and reducing the NOx to nitrogen in an atmosphere of excess reducing species,
In the heat exchanger, the heat storage chamber, an exhaust area through which high-temperature treated exhaust gas discharged from the exhaust gas processing chamber passes,
The air supply region through which the low-temperature untreated exhaust gas introduced into the exhaust gas treatment chamber passes, and at least three regions of an exhaust gas blocking region that blocks the flow of the untreated exhaust gas and the treated exhaust gas, are divided into at least three regions, and these regions are sequentially arranged. A switching supply / exhaust distribution device is provided, and a reducing gas supply device that supplies a reducing gas from the exhaust gas cutoff region and exposes a catalyst layer facing the region to a reducing species excess atmosphere is provided. .

According to the present invention, the supply / exhaust distribution device includes:
The heat storage chamber is divided into an air supply area, an exhaust area, and an exhaust gas cutoff area, and the untreated exhaust gas supplied from the air supply area passes through the catalyst layer facing it, and then passes through the catalyst layer facing the exhaust area. And is discharged. At this time, if the exhaust gas treatment chamber is maintained at a predetermined catalyst combustion temperature, VOCs (volatile organic compounds) contained in the exhaust gas are burned in the catalyst layer.

Further, since the catalyst layer is formed of a NOx storage reduction type catalyst, and the untreated exhaust gas and the treated exhaust gas contain oxygen, the catalyst layer facing the air supply region and the exhaust region has an oxygen excess. Exposure to atmosphere. As a result, NOx contained in the exhaust gas is stored, and the treated exhaust gas from which NOx has been removed is discharged through the exhaust region.

On the other hand, in the exhaust gas cut-off region, the flow of the untreated exhaust gas containing oxygen and the processed exhaust gas is cut off, and at the same time, the reducing gas forming the excess atmosphere of the reducing species is supplied. the catalyst layer has a exposed to the reducing species-rich atmosphere when the reducing gas passes through the previously occluded NOx is reduced to nitrogen (N _2), and discharges harmless.

As described above, while the VOC is combusted by the catalyst layer facing the air supply region and the exhaust region and the exhaust gas is purified by occluding NOx, the catalyst layer facing the exhaust gas cutoff region stores the NOC. Since NOx is reduced to nitrogen and discharged, by sequentially switching these regions,
Exhaust gas treatment can be performed continuously.

Since the high-temperature treated exhaust gas and the low-temperature untreated exhaust gas are heat-exchanged through a heat-storage heat exchanger having high heat efficiency, the running cost is reduced.

Moreover, if hydrocarbons (HC) burned in the presence of a catalyst are used as the reducing gas, the burner starts operating because the exhaust gas processing chamber is maintained at the catalytic combustion temperature by burning the reducing gas. It is enough to burn only when the temperature rises. This hydrocarbon is inexpensive compared to ammonia, and since it is not necessary to supply fuel to the burner during operation, fuel economy can be saved and running costs can be further reduced.

[0017]

Embodiments of the present invention will be specifically described below with reference to the drawings. 1 is a schematic configuration diagram showing a heat storage type exhaust gas treatment apparatus according to the present invention, FIG. 2 is a cross-sectional view thereof, FIG. 3 is a schematic configuration diagram showing another embodiment, and FIG. 4 is a cross-sectional view thereof.

The heat storage type exhaust gas treatment apparatus 1 shown in FIGS. 1 and 2 is provided with an exhaust gas treatment chamber 3 for purifying exhaust gas at the upper stage of a cylindrical treatment tower 2 and a heat storage room 4 at the lower stage. A regenerative heat exchanger 5 is formed.

In the exhaust gas treatment chamber 3, a catalyst layer 6 is formed facing the heat storage chamber 4 of the heat exchanger 5, and a burner 7 for raising the temperature of the catalyst layer 6 to a predetermined catalyst combustion temperature is arranged. Has been established. The catalyst layer 6 is composed of VOCs contained in the exhaust gas.
NOx having the function of burning (volatile organic compound) at a predetermined catalytic combustion temperature, storing NOx in a lean state (oxygen excess atmosphere), and reducing the NOx to nitrogen in a rich state (reducing species excess atmosphere). An occlusion reduction type catalyst is used. For example, platinum P
Noble metals such as t and rhodium Rh are supported, and N
Alkali metals such as lithium Li and potassium K, alkaline earth metals such as barium Ba,
One or more substances such as rare earth metals are supported.

The heat storage chamber 4 is filled with a heat storage material M formed of an alumina honeycomb structure or the like. In the regenerative heat exchanger 5, the heat storage chamber 4 is provided with an exhaust region 4out through which high-temperature treated exhaust gas passes, air supply regions 4in and 4in through which low-temperature untreated exhaust gas passes, Exhaust gas cutoff area 4s to cut off the flow of treated exhaust gas
And a rotary valve (supply / exhaust distribution device) 8 which divides the treated exhaust gas discharged to the outside into purge areas 4p and 4p for sequentially switching these areas, and is provided through an exhaust gas cutoff area 4s. There is provided a reducing gas supply device 9 that makes the catalyst layer 6 facing the region 4s rich.

The rotary valve 8 includes a diffuser 11
A rotor 13 that communicates with the bottom surface of the heat storage chamber 4 through the valve casing 12 and that divides the heat storage chamber 4 into respective regions is rotatably disposed in the valve casing 12. The inside of the diffuser 11 is radially partitioned by 5 ° to 15 °,
A large number of 2 to 24 exhaust gas channels 10 are formed.

The rotor 13 is provided with a rotary disk 14A facing the diffuser 11, and the rotary disk 14A has an exhaust opening 15out for discharging the treated exhaust gas passing through the heat storage chamber 4. An air supply opening 15in for introducing the untreated exhaust gas into the heat storage chamber 4, a shielding portion 15s for blocking the flow of the untreated exhaust gas and the treated exhaust gas in the heat storage chamber 4; Purge openings 15p, 15p for recirculating a part to the heat storage chamber 4 are formed.

Here, the purging openings 15p, 15p
Is formed between the air supply opening 15in and the exhaust opening 15out, so that the rotating disk 14A and the diffuser 1
An air seal for preventing untreated exhaust gas from leaking to the exhaust side from the gap 1 is also used.

Each of the openings 15out, 15in, the shielding part 1
5s and the opening 15p are located in the respective regions 4out, 4i of the heat storage chamber 4.
n, 4s, 4p, an exhaust opening 15out having a central angle of about 170 ° and a first purging opening having a central angle of about 27 ° from the front to the rear in the rotation direction of the rotating disk 14A. Part 15p, a first air supply opening 15in having a central angle of about 27 °, a shielding part 15s having a central angle of about 10 °, and a central angle of about 10 °
A second air supply opening 15in of 0 ° and a second purge opening 15p having a central angle of about 27 ° are formed in this order.

The rotor 13 is provided with a predetermined space along the axial direction of the rotating shaft 13a.
An exhaust chamber 16out communicating with the exhaust opening 15out, and a purge chamber 16p communicating with the purge openings 15p, 15p.
Rotating disks 14B and 14C are provided at predetermined intervals to partition the air supply chamber 16in communicating with the air supply opening 15in.

Here, the purge chamber 16p is provided with an exhaust chamber 16ou.
Since it is formed between t and the air supply chamber 16in, it also serves as an air seal, and the untreated exhaust gas fed to the air supply chamber 16in does not leak directly to the exhaust chamber 16out.

The exhaust chamber 16out is connected to an exhaust duct 17out for discharging treated exhaust gas to the outside, and the air supply chamber 16in is connected to an air supply duct 17in for supplying untreated exhaust gas from an exhaust gas generation source. A purge duct 17p branched from the exhaust duct 17out is connected to the purge chamber 16p.

The reducing gas supply device 9 is a reducing gas supply pipe 1 for supplying hydrocarbons, for example, propylene, burned in the presence of a catalyst to each exhaust gas passage 10 of the diffuser 11.
, And the on-off valves 19 interposed in the respective reducing gas supply pipes 18, and the reduction connected to the exhaust gas passage 10 communicated with the exhaust gas cutoff region 4 s in synchronization with the rotation of the rotor 13. An opening / closing control device 20 for opening the opening / closing valve 19s of the gas supply pipe 18s is provided.

The control device 20 has a rotor 13 on its input side.
A rotary encoder 21 for detecting the position of the shielding portion 15s based on the rotation angle of the shutter 15 is connected, and each open / close valve 19 is connected to the output side, and is blocked by the shielding portion 15s according to the position of the shielding portion 15s. Gas supply pipe 18s connected to the exhaust gas passage 10 of the diffuser 11
A control signal for opening the valve is output to the open / close valve 19s.

The above is an example of the configuration of the present invention, and its operation will be described below. First, in a state where the burner 7 is burned and the exhaust gas treatment chamber 3 is heated to a predetermined catalyst combustion temperature,
While rotating the rotor 13 at 1/5 to 3 rpm, processing of exhaust gas supplied from an exhaust gas generation source (not shown) such as a drying furnace for coating is performed.

The untreated exhaust gas sent through the air supply duct 17in passes through the air supply chamber 16in {the air supply opening 15in} the exhaust gas flow path 10 and passes through the air supply area 4in of the heat storage chamber 4. And is introduced into the exhaust gas treatment chamber 3.

Since the exhaust gas treatment chamber 3 is maintained at a predetermined catalytic combustion temperature, the VOC contained in the untreated exhaust gas is reduced by the catalyst layer 6 facing the supply region 4in and the catalyst layer 6 facing the exhaust region 4out. Burned. Further, since the exhaust gas introduced into the exhaust gas treatment chamber 3 contains oxygen, the catalyst layer 6 facing the air supply region 4in and the exhaust region 4out is in a lean state, and as a result, NOx contained in the exhaust gas is oxidized. And stored as nitrate (NO ₃ ) ^— .

The treated exhaust gas from which VOCs and NOx have been removed in the catalyst layer 6 of the exhaust gas treatment chamber 3 in this way is recovered after the heat is recovered when passing through the exhaust region 4out of the heat storage chamber 4, and then diffused. The exhaust gas is discharged to the outside through the exhaust gas passage 10 of the exhaust gas outlet 15out of the rotor 13, the exhaust chamber 16out of the rotary valve 8 and the exhaust duct 17out.

On the other hand, in the exhaust gas passage 10 in which the flow of the untreated exhaust gas and the treated exhaust gas is blocked by the shielding portion 15s of the rotor 13, the propylene (C ₃
A reducing gas composed of a hydrocarbon such as H ₆ ) is supplied, and the reducing gas passes through the exhaust gas passage 10 and the exhaust gas cutoff region 4 s and reaches the catalyst layer 6 facing the same.

At this time, since the reducing gas is supplied to the narrow exhaust gas cut-off region 4s partitioned in the heat storage chamber 4, the oxygen in the exhaust gas passage 10 and the exhaust gas cut-off region 4s is pressed out, and the rotary valve 8 Since no untreated exhaust gas is introduced from the side, no oxygen is supplied. Therefore, the catalyst layer 6 surely becomes rich, and the catalyst layer 6
Nitrates (NO ₃₎ the ^- stored NOx of oxygen and propylene (C ₃ H ₆₎ is combusted in the reaction as a nitrogen (N ₂₎ and water (H ₂ O) and carbon dioxide (CO ₂₎ is generated Is done. As a result, NOx is reduced to nitrogen (N ₂ ) and discharged, and discharged to the outside through the exhaust region 4out.
Here, even if an excess portion of the reducing gas passes through the catalyst layer 6, it reacts with the oxygen contained in the exhaust gas introduced into the exhaust gas treatment chamber 3 and is burned, so that the reducing gas is directly discharged to the outside. Never.

When a hydrocarbon such as propylene is supplied as a reducing gas, heat is generated when the hydrocarbon is burned in the catalyst layer 6, and this heat and VOC contained in the exhaust gas are generated when the catalyst is burned in the catalyst layer 6. By the heat, the catalyst layer 6 is maintained at a predetermined catalyst combustion temperature, and after starting the exhaust gas treatment, the burner 7
This eliminates the need to heat the inside of the exhaust gas treatment chamber 3. Therefore, it is only necessary to supply fuel to the burner 7 for several tens of minutes when the exhaust gas treatment device 1 is started up, and the fuel cost can be greatly reduced.

Further, according to the experiment of the inventor, in the exhaust gas treatment apparatus 1 according to the present invention, the storage time / reduction time of NOx is sufficient to be about 1/120.
When rotating at 1/2 rpm, it is sufficient to supply the reducing gas in a rich state for only one second.

Here, the shielding portion 15s is selected at 10 °,
If the central angle of each exhaust gas passage 10 of the diffuser 11 is selected to be 5 °, the time during which one exhaust gas passage 10 is blocked by the shielding portion 15s is about 1.6 seconds, and the occlusion in the catalyst layer 6 is achieved. Sufficient time is ensured to reduce the NOx to nitrogen (N ₂ ).

In this manner, VOC is burned and NOx is absorbed by the catalyst layer 6 facing the supply region 4in and the exhaust region 4out, and is converted to nitrogen (N ₂ ) by the catalyst layer 6 facing the exhaust gas cutoff region 4s. Since each region in the heat storage chamber 4 is sequentially switched by rotating the rotor 13,
It is possible to alternately store and reduce NOx while continuously performing the exhaust gas purification process without interruption.

In the above description, the diffuser 11
The case in which the reducing gas supply pipes 18 are connected to the respective exhaust gas passages 10 and the valves 19 are sequentially opened and closed to supply the reducing gas to the exhaust gas cutoff region 4s has been described. As described above, the reducing gas may be supplied through a rotary valve.

In this case, a rotary disk 33A is attached to the rotor 32 of the rotary valve (supply / exhaust distribution device) 31 so as to face the bottom surface of the heat storage chamber 4, and the rotary disk 33A is
From the front to the rear in the rotation direction, the exhaust opening 1
5out, a first purge opening 15p, a first air supply opening 15in, and a reducing gas supply opening 15g for supplying a reducing gas by interrupting the flow of untreated exhaust gas and treated exhaust gas. , A second air supply opening 15in and a second purge opening 15p.

The rotor 32 is provided with rotating disks 33B, 33C and 33D at predetermined intervals on a rotating shaft 32a.
, Purge chamber 16p, reducing gas chamber 16g, air supply chamber 16in
And the reducing gas chamber 16g communicates with the reducing gas supply opening 15g.

A reducing gas supply pipe 34 is connected to the reducing gas chamber 16g, and the supply pipe 34 is connected to the reducing gas chamber 16g.
And the reducing gas supply device 15 with the reducing gas supply opening 15g.
5 are formed. The reducing gas is supplied to the reducing gas chamber 16g such that the internal pressure of the reducing gas chamber 16g becomes higher than that of the adjacent purge chamber 16p and air supply chamber 16in. Accordingly, air containing oxygen does not flow into the reducing gas chamber 16g, and even if the reducing gas flows out into the air supply chamber 16in or the purge chamber 16p, it is sent to the exhaust gas processing chamber 3 and burned. It does not leak to the outside. In addition, other configurations,
The exhaust gas treatment procedure and the action of removing VOC and NOx contained in the exhaust gas are exactly the same as those of the exhaust gas treatment apparatus 1 shown in FIGS.

According to this embodiment, by continuously supplying the reducing gas from the reducing gas supply pipe 34, the reducing gas can be supplied to the catalyst layer 6 facing the exhaust gas cutoff region 4s via the rotary valve 31. There is no need for complicated valve control by providing a large number of reducing gas supply pipes.

In the above description, the case where a hydrocarbon such as propylene is used as the reducing gas has been described. However, the present invention is not limited to this, and any one that can consume oxygen can be used. Ammonia (NH ₃ ),
Hydrogen (H ₂ ) or another reducing gas may be used. However, hydrocarbons are inexpensive as compared with other reducing gases such as ammonia, and furthermore, during operation, they are catalyzed and generate heat, so that the heat keeps the exhaust gas treatment chamber 3 at the catalyzed combustion temperature and causes the burner to burn. There is an advantage that it is not necessary to combust the fuel, and thus the running cost is further reduced.

[0046]

As described above, according to the present invention, the catalyst layer facing the air supply area and the exhaust area is exposed to an oxygen-excess atmosphere, burns VOC, stores NOx, and enters the exhaust gas cutoff area. The exposed catalyst layer is exposed to a reducing species excess atmosphere and reduces the previously stored NOx to nitrogen. Therefore, even when a large amount of exhaust gas is supplied, the supply region, the exhaust region, and the exhaust gas shut-off region are not changed. By sequentially switching, there is an extremely excellent effect that NOx purification processing can be performed while continuously burning VOCs.

In this case, even if the capacity of the exhaust gas treatment chamber is large, only the catalyst layer facing the exhaust gas cut-off region is exposed to the reducing species excess atmosphere, so that it is necessary to expose the region to the reducing species excess atmosphere. It is sufficient to supply the reducing gas only in an amount, and it is not necessary to expose the entire exhaust gas treatment chamber to an atmosphere of excess reducing species. Therefore, there is an excellent effect that the amount of the reducing gas used can be saved and the running cost can be greatly reduced.

Further, when a hydrocarbon is used as the reducing gas, the exhaust gas processing chamber is heated by heat generated when the hydrocarbon is burned in the catalyst layer, so that the fuel gas supplied to the burner is reduced. This has the effect of saving money and reducing running costs.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of a heat storage type exhaust gas treatment apparatus according to the present invention.

FIG. 2 is a sectional view thereof.

FIG. 3 is a schematic configuration diagram showing another embodiment.

FIG. 4 is a sectional view thereof.

FIG. 5 is an explanatory view showing a conventional device.

[Explanation of symbols]

1 ··· Heat storage type exhaust gas treatment device 3 ··· Exhaust gas processing chamber 4 ··· Heat storage chamber 4out ··· Exhaust area 4in ··· Supply air area 4s ··· Exhaust gas cutoff area 5 ··· Heat storage Type heat exchanger 6 ··· Catalyst layer 8 · 31 ··· Rotary valve (supply / exhaust distribution device) 9 ··· Reducing gas supply device 10 ··· Exhaust gas channel 11 ··· Diffuser 12 · ... Valve casing 13,32 ... Rotor 15out ... Exhaust opening 15in ... Air supply opening 15s ... Shielding part 18,18s ... Reducing gas supply pipe 19,19s
· Opening / closing valve 20 ··· Opening / closing control device 15g ··· Opening for reducing gas supply 34 ··· Reduction gas supply pipe 35 ··· Reduction gas supply device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B01D 53/81 B01D 53/34 117E 53/86 129A 53/94 53/36 G F23G 7/06 ZAB 102H 102 103 F-term (reference) 3K078 AA05 BA06 BA17 BA24 DA14 DA16 DA17 DA24 DA32 EA02 EA09 4D002 AA12 AA33 AB03 AC10 BA04 BA06 CA20 DA01 DA04 DA07 DA25 DA46 DA54 DA56 GA01 GA02 GB20 HA08 HA10 4D048 AA06 AA18 BA30 BAX BAX BAXX CC32 CC54 EA10

Claims (4)

[Claims] An exhaust gas treatment chamber (3) in which a catalyst layer (6) for burning volatile organic compounds contained in exhaust gas is formed,
In a heat storage type exhaust gas treatment device formed in communication with a heat storage type heat exchanger (5) provided with a heat storage room (4), the catalyst layer (6) includes a heat storage room (5) of the heat storage type heat exchanger (5). 4) and N 2 in an oxygen-excess atmosphere
The heat exchanger (5) includes the heat storage chamber (4) and the exhaust gas treatment chamber. The NOx storage reduction catalyst has a function of storing Ox and reducing the NOx to nitrogen in an atmosphere of excess reducing species. An exhaust area (4out) through which the high-temperature treated exhaust gas discharged from (3) passes, and the exhaust gas processing chamber (3)
Each of these regions is divided into at least three regions: an air supply region (4 in) through which the low-temperature untreated exhaust gas introduced into the gas passes, and an exhaust gas blocking region (4s) that blocks the flow of the untreated exhaust gas and the treated exhaust gas. A supply / exhaust distribution device (8, 31) for sequentially switching the exhaust gas is provided, and a reducing gas is supplied from the exhaust gas cut-off area (4s) to expose the catalyst layer (6) facing the area to an atmosphere containing excess reducing species. A heat storage type exhaust gas treatment device comprising a gas supply device (9, 35). 2. The regenerative exhaust gas treatment apparatus according to claim 1, wherein the reducing gas is a hydrocarbon combusted in the presence of a catalyst. 3. The heat storage chamber (4), wherein the air supply / exhaust distribution device is provided in the heat storage chamber (4).
An exhaust opening (15out) for discharging the treated exhaust gas that has passed through, a gas supply opening (15in) for introducing the untreated exhaust gas into the heat storage chamber (4), and a heat storage chamber (4). It comprises a rotary valve (8) having a rotor (13) formed with a shielding part (15s) for blocking the flow of untreated exhaust gas and treated exhaust gas, and the rotary valve (8) and the heat storage chamber (4) Are connected via a diffuser (11) that is radially partitioned to form a large number of exhaust gas channels (10 ...), and the reducing gas supply device (9) is connected to the diffuser (1).
The reducing gas supply pipes (18 ...) connected to the respective exhaust gas flow paths (10 ...) of 1), the opening / closing valves (19 ...) interposed in the respective reducing gas supply pipes (18 ...), and the rotor In synchronization with the rotation of (13), an opening / closing controller (19) that opens and closes the opening / closing valve (19s) of the reducing gas supply pipe (18s) connected to the exhaust gas flow path (10) blocked by the shielding section (15s). The heat storage type exhaust gas treatment apparatus according to claim 1 or 2, further comprising (20). 4. The air supply / exhaust distribution device, wherein the heat storage chamber (4) is provided.
An exhaust opening (15out) for discharging the treated exhaust gas that has passed through, a gas supply opening (15in) for introducing the untreated exhaust gas to the heat storage chamber (4), and an exhaust opening for the untreated exhaust gas and the treated exhaust gas. A rotary valve (31) having a rotor (32) formed with a reducing gas supply opening (15g) for supplying a reducing gas to the heat storage chamber (4) by interrupting the flow; The regenerative exhaust gas according to claim 1 or 2, wherein a reducing gas supply pipe (34) is connected to a reducing gas chamber (16g) of a rotary valve (31) communicating with the reducing gas supply opening (15g). Processing equipment.