JP2001025643A - Exhaust gas treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To treat exhaust gas with high efficiency by setting the superficial velocity in a cylindrical body to the optimum speed by constituting an exhaust gas inlet, an exhaust gas outlet and the cylindrical body so that the speed of the exhaust gas flowing in the cylindrical body from the exhaust gas inlet becomes larger than that of the exhaust gas flowing out to the exhaust gas inlet from the cylindrical body. SOLUTION: The exhaust gas from a motor or the like is introduced into a housing 4 through an exhaust gas inlet 5 while a reducing agent is injected in the exhaust gas from a reducing agent injection pipe 12. A cylindrical body 20 rotated by a motor is housed in the housing 4 and exhaust gas flows in the soot roughly removing zone 21 of a catalyst packed bed 3 and soot with a relative large particle size is caught. Next, the exhaust gas flows through the inner passage 10 of the cylindrical body 20 while expands at an angle αto be reduced in its speed and flows in the precise dust removing/denitrating/ desulfurizing zone 22 on the side of an exhaust gas outlet 6. Herein, soot with a fine particle size is caught and NOx is removed by a denitrating active catalyst particles while SOx and H2S are removed by desulfurizing active catalyst particles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of purifying exhaust gas by providing a packed layer of catalyst particles inside a rotatably driven cylinder, and allowing exhaust gas to flow in a direction substantially perpendicular to the packed layer. To an exhaust gas treatment device.

[0002]

2. Description of the Related Art A packed layer of catalyst particles is provided between an outer cylinder and an inner cylinder of an annular cylinder which is driven to rotate, and exhaust gas flows through the packed layer from a direction substantially perpendicular to the packed layer to contact the packed layer. Japanese Patent Application Laid-Open No. 4-34991 is one of the exhaust gas treatment apparatuses designed to
The invention provided in No. 4 is shown in FIG.

In FIG. 3, reference numeral 012 denotes an exhaust gas inlet;
4 is an exhaust gas outlet, 030 is a cylindrical body driven to rotate, 010
Is a housing. The cylinder 030 includes an inner cylinder 018, an outer cylinder 016, and a packed layer 020 of catalyst particles filled between the inner cylinder 018 and the outer cylinder 016. Numeral 034 is a dust removal zone, 036 is a precision dust removal and denitration / desulfurization zone, 038 is a regeneration zone for separating dust and regenerating a catalyst, and 030 is a dust (dust) discharge port.

[0004] In this invention, the exhaust gas is filled in the packed bed 020 filled in the rotating hollow cylinder 030.
By passing the waste gas twice, capture of dust in the exhaust gas, denitration (removal of NOx), and desulfurization (removal of SOx, H ₂ S, etc.) are simultaneously performed. The exhaust gas treatment device enables continuous operation of the device by separating dust and regenerating the catalyst during the rotation of the packed bed 020.
At this time, the exhaust gas inlet 012 for introducing the exhaust gas is used.
(Width B ₁ ) and the exhaust gas outlet (Width B ₂ ) for discharging the purified exhaust gas have the same area.

[0005]

In such an exhaust gas treatment apparatus, when removing dust (dust removal), denitration and desulfurization are performed simultaneously, coarse particles of dust are captured in a zone 034 on the exhaust gas inlet 012 side. In order to efficiently remove the dust, it is necessary to increase the processing speed of the exhaust gas in the packed bed 020, that is, the superficial superficial velocity.

[0006] On the other hand, when removing dust particles (dust particles having a particle diameter of several microns) after the above-described roughing, and in the zone 036 in which denitration and desulfurization are carried out by a catalyst, these treatments are efficiently carried out. It is necessary to reduce the superficial velocity in order to perform the above.

However, in the prior art as shown in FIG. 3, the flow passage area of the exhaust gas inlet 012 and the exhaust gas outlet 014 is the same (width B ₁ = B ₂ ). When the flow path area on the exhaust gas inlet side is set in order to perform the dust removal with high efficiency by setting the superficial velocity in the zone 034 of the exhaust gas to the optimum value, the exhaust gas inlet 01
In the zone 036 on the fourth side, the superficial superficial velocity becomes excessive, and it becomes difficult to remove fine dust and to perform denitration and desulfurization with high efficiency. That is, in such a conventional technique, since the superficial velocity in the processing zone 034 on the exhaust gas inlet side and the processing zone 036 on the exhaust gas outlet side are the same, it is difficult to perform high-efficiency exhaust gas processing in both zones. There is a problem that.

[0008] In addition to the above-mentioned prior art, utility model registration No. 25
Also in No. 26248, dust is removed by passing exhaust gas through a cylindrical catalyst packed bed that is driven to rotate,
Although a technique for performing denitration and desulfurization is provided, even in such a conventional technique, the superficial velocities on the exhaust gas inlet side and the exhaust gas outlet side are the same, and have the same problems as described above.

The present invention has been made in view of the problems of the prior art,
In an exhaust gas treatment apparatus in which exhaust gas is caused to flow substantially orthogonally to a cylindrical catalyst bed that is driven to rotate, and to perform dust removal, denitration, and desulfurization of the exhaust gas, the exhaust gas is not complicated. It is an object of the present invention to provide an exhaust gas treatment apparatus capable of setting a superficial velocity in an inlet-side treatment zone and an exhaust gas outlet-side treatment zone to an optimum speed, thereby performing a highly efficient exhaust gas treatment operation.

[0010]

According to the present invention, in order to solve the above-mentioned problems, a packed bed of catalyst particles is provided inside a rotatably driven cylindrical body.
An exhaust gas inlet and an exhaust gas outlet are provided in a direction substantially perpendicular to the axis of the cylinder and open toward the outer peripheral surface of the cylinder, and exhaust gas is discharged from the exhaust gas inlet to the cylinder while rotating the cylinder. In the exhaust gas treatment device, which is guided into the body and brought into contact with the catalyst through the catalyst packed layer in the cylinder, and then led to the exhaust gas outlet, the exhaust gas inlet, the exhaust gas outlet, and the cylinder are connected to the exhaust gas inlet through the exhaust gas inlet. An exhaust gas treatment device is proposed wherein the speed of exhaust gas flowing into the cylinder is higher than the speed of exhaust gas flowing from the cylinder to the exhaust gas outlet.

[0011] The invention according to claims 2 and 3 is the first invention.
According to a specific configuration of the invention described in claim 2, the invention described in claim 2 is configured such that in claim 1, the exhaust gas passage area on the exhaust gas outlet side is larger than the exhaust gas passage area on the exhaust gas inlet side.

According to a third aspect of the present invention, in the first aspect, the cylindrical body is formed into an annular body including an outer cylinder and an inner cylinder each having a plurality of exhaust gas passage holes. An inner passage in which a packed layer of the catalyst particles is formed in an annular space between the inner cylinder and an exhaust gas passing from the exhaust gas inlet through a packed layer on one side of the cylindrical body is formed inside the inner cylinder. In the above, after being decelerated, it is configured to be guided to the exhaust gas outlet side via the packed layer on the other side in the cylinder.

According to this invention, while rotating the cylinder having the packed layer of the catalyst particles between the outer cylinder having the exhaust gas passage hole and the inner cylinder, the axis is substantially orthogonal to the axis of the cylinder. The gas flows from the exhaust gas inlet provided to the exhaust gas outlet through the catalyst packed bed of the cylindrical body.

During the flow of the exhaust gas, the flow passage area on the exhaust gas inlet side of the cylinder is smaller than the flow passage area on the exhaust gas outlet side. Since it is configured to be higher than the speed, the superficial velocity in the exhaust gas inlet side packed bed of the cylindrical body is higher than the superficial velocity in the exhaust gas outlet side packed bed. For this reason, dust having a relatively large particle diameter at the exhaust gas inlet side is trapped, that is, roughed, at a high speed, so that the dust can be roughly removed with high efficiency.

The exhaust gas from which the dust has been roughly removed through the catalyst packed bed on the exhaust gas inlet side is decelerated in an internal passage formed in the hollow portion of the cylinder, and passes through the catalyst packed bed on the exhaust gas outlet side. Shed. At this time, since the superficial velocity on the exhaust gas outlet side is smaller than the superficial velocity on the exhaust gas inlet side as described above, in the catalyst packed bed on the exhaust gas outlet side,
At such a low speed, the capture, denitration, and desulfurization of dust having a small particle size are performed with high efficiency.

That is, according to the present invention, the superficial velocity optimal for rough removal of dust in the catalyst packed bed on the exhaust gas inlet side and the optimum for precise dust collection, denitration and desulfurization of dust in the catalyst packed bed on the exhaust gas outlet side. By setting the superficial superficial velocity and performing the exhaust gas treatment at such an optimum speed, it becomes possible to carry out dust removal, denitration and desulfurization of the exhaust gas with high efficiency. In addition, the above-described high-efficiency exhaust gas treatment can be performed with a simple structure in which the widths of the exhaust gas inlet and the exhaust gas outlet are changed.

Further, according to a fourth aspect of the present invention, in addition to the third aspect, the exhaust gas inlet and the exhaust gas outlet are
A regenerator is provided at an axially symmetric position with respect to the rotation center of the cylinder, removes dust in a packed layer in the cylinder at a circumferentially intermediate portion between the exhaust gas inlet and the exhaust gas outlet, and regenerates a catalyst, An annular cylinder is configured to circulate from the exhaust gas outlet side to the exhaust gas inlet side via the regenerating device.

According to a fifth aspect of the present invention, in addition to the fourth aspect, a dust outlet for discharging the dust treated by the regenerator is provided at the outlet of the regenerator.

According to this invention, after capturing the large-diameter dust at the exhaust gas inlet side, the catalyst-packed layer is rotated and subjected to denitration and desulfurization with the fine-particle dust and the catalyst at the exhaust gas outlet side. The dust is separated and the catalyst is regenerated by a regenerating device provided at a circumferentially intermediate position between the outlet side and the inlet side, and the state is returned to a clean state. Thereby, dust removal, denitration, desulfurization treatment and regeneration of the catalyst packed layer of the exhaust gas can be continuously performed.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to an embodiment shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not merely intended to limit the scope of the present invention, but are merely illustrative examples unless otherwise specified. Absent.

FIG. 1 is a cross-sectional view of a main part of an exhaust gas treatment apparatus according to an embodiment of the present invention (a cross-sectional view taken along line AA in FIG. 2), FIG.
FIG. 2 is a vertical sectional view of a main part of the exhaust gas treatment device.

1 to 2, reference numeral 4 denotes a housing, 2
Reference numeral 0 denotes a cylindrical body rotatably supported by the housing 4. Reference numeral 9 denotes a motor, and 7 denotes a rotating shaft for transmitting the rotation of the motor 9 to the cylindrical body 20. The cylindrical body 20 is formed in an annular shape by an inner cylinder 1 having a large number of exhaust gas passage holes 1a and an outer cylinder 2 having a large number of exhaust gas passage holes 2a. A catalyst packed layer 3 filled with the dust trapping particles and the catalyst particles is provided in the annular space therebetween.

The inner cylinder 1 and the outer cylinder 2 are constituted by a punching metal made of a heat-resistant metal material, a wire mesh, a perforated plate or the like. The catalyst-packed layer 3 includes alumina, mullite,
Particles for removing dust, preferably having a particle size of 1 mm to 5 mm, formed of ceramic granules such as silica, catalyst particles having a denitration activity for removing NOx, and catalyst particles having a desulfurization activity for removing SOx and H ₂ S, All particles with catalyst particles having simultaneous denitration activity and desulfurization activity or, if necessary, at least one kind of particles are filled.

In the housing 4, an exhaust gas inlet 5 for introducing exhaust gas and an exhaust gas outlet 6 for deriving purified exhaust gas are axially symmetrical with respect to the rotation axis 20 a of the cylindrical body 20 (although not necessarily axially symmetrical). Good).
As shown in FIG. 2, the exhaust gas inlet and the exhaust gas outlet 6 are opened over the entire length of the cylindrical body 20 in the height direction (axial direction of the cylindrical body 20), while being opened in the width direction, that is, the rotation direction. in the direction perpendicular to the axis 20a, as shown in FIG. 1, the width B ₁ of the exhaust gas inlet 5 is formed to be smaller than the width B ₂ of the exhaust gas outlet.

The width B ₁ of the exhaust gas inlet 5 is such that the superficial velocity of the exhaust gas flowing through the inlet 5 in the inlet side zone of the catalyst packed bed 3 of the cylindrical body 20, that is, in the dust removal zone 21 is reduced. , Preferably set to about 0.3 m / s to 1.0 m / s. The width B ₂ of the exhaust gas outlet 6 is preferably such that the superficial velocity in the outlet-side zone of the catalyst packed bed 3 before flowing out to the exhaust gas outlet 6, that is, the precision dust removal / denitrification / desulfurization zone 22, is 0.1 m / s. ~ 0.5m / s
Set to about.

Reference numeral 11 denotes a regenerator installed at a circumferentially intermediate position between the exhaust gas outlet 6 and the exhaust gas inlet, and 14 denotes a dust discharge port for discharging the dust removed by the regenerator 11. Reference numeral 12 denotes a reducing agent injection pipe opened on the upstream side of the exhaust gas inlet 5, and reference numeral 13 denotes an on-off valve of the injection pipe 12.

During operation of the exhaust gas treatment apparatus having the above configuration, exhaust gas from an exhaust gas source (not shown) such as a prime mover is injected with a reducing agent from a reducing agent injection pipe 12 on the upstream side of the exhaust gas inlet 5 and then exhausted. Reach entrance 5. On the other hand, the cylindrical body 20 is rotated at a predetermined rotational speed by a motor 9, and exhaust gas flows from the exhaust gas inlet 5 into the exhaust gas passage hole 2 a of the outer cylinder 2 constituting the cylindrical body 20 performing such rotational movement. Through the exhaust gas inlet side of the catalyst packed bed 3,
That is, it flows into the dust removal zone 21.

Since the exhaust gas inlet 5 is set to have a width B ₁ so as to have a required superficial velocity as described above, the exhaust gas inlet 5 passes through the exhaust gas roughing zone 21.
Exhaust gas flowing through the space has a superficial velocity of 0.3 m / s
The dust flows in the catalyst packed bed 3 at a relatively high speed of 1.0 m / s, and coarse dust having a large particle diameter in the dust is captured by the dust removing particles in the packed bed 3.

The exhaust gas leaving the dust removal zone 21 is:
Since the exhaust gas outlet 6 as described above is larger than the width B ₁ of the exhaust gas inlet 5 and the width B _2, as shown in FIG. 1, the inside of the internal passage 10 of the tubular body 20 the angle α of the By spreading and flowing as described above, the flow velocity is reduced and flows into the catalyst packed bed 3 on the exhaust gas outlet 6 side, that is, into the precision denitration / denitration / desulfurization zone 22.

The exhaust gas flowing through the zone 22 has a width B ₂ such that the exhaust gas outlet 6 has the required superficial velocity as described above.
Therefore, the air flows at a superficial velocity of 0.1 m / s to 0.5 m / s in the dust removal zone 21 on the inlet side. Due to the flow of the exhaust gas at a low speed due to the superficial velocity, the dust having a small diameter in the exhaust gas is efficiently captured by the dust removing particles, and the NOx removing action by the denitration active catalyst particles and the SOx and The H ₂ S removal is effected with maximum efficiency.

As described above, after the catalyst-packed layer 3 captures large-diameter dust in the dust roughing zone 21, the catalyst-packed layer 3 shown in FIG.
As shown by the arrow N in the drawing, the dust is rotated approximately １ ／, and the fine dust is captured in the precision denitrification and denitrification desulfurization zone 22, NOx is removed by the denitration catalyst particles, and SOx and H _{2 are} removed by the desulfurization catalyst particles.
S and the like are removed, and further rotated to reach the regenerating apparatus 11, where the captured dust is separated and the catalyst is regenerated and purified, and the dust is removed to the dust roughing zone 21. Is returned. This makes it possible to continuously perform dust removal, denitration, desulfurization treatment of the exhaust gas, and regeneration and cleaning of the catalyst packed layer 3.

[0032]

As described above, according to the present invention, an optimal superficial velocity for roughly removing dust in the catalyst packed bed on the exhaust gas inlet side and precise dust collection and denitration of dust in the catalyst packed bed on the exhaust gas outlet side. By setting the optimal superficial velocity for desulfurization and performing exhaust gas treatment at such optimal velocity,
Exhaust gas can be removed, denitrated, and desulfurized with high efficiency. In addition, the above-described high-efficiency exhaust gas treatment can be performed with a simple structure in which the widths of the exhaust gas inlet and the exhaust gas outlet are changed.

Further, according to the structure of the fourth aspect, dust removal, denitration, desulfurization treatment and regeneration of the catalyst packed layer of the exhaust gas can be continuously performed, and the operation efficiency of the exhaust gas treatment device can be kept high.

[Brief description of the drawings]

FIG. 1 is a sectional configuration diagram (a sectional view taken along line AA in FIG. 2) of a main part of an exhaust gas treatment apparatus according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional configuration view of a main part of the exhaust gas treatment apparatus.

FIG. 3 is a diagram corresponding to FIG. 1 showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner cylinder 1a Exhaust gas passage hole 2 Outer cylinder 2a Exhaust gas passage hole 3 Catalyst filling layer 4 Housing 5 Exhaust gas inlet 6 Exhaust gas outlet 7 Rotary shaft 9 Motor 10 Internal passage 11 Regeneration device 12 Reducing agent injection pipe 14 Dust discharge pipe 20 Cylindrical body 21 Soot and dust removal zone 22 Precision dust removal and denitrification desulfurization zone

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01D 53/96 B01D 53/36 102E (72) Inventor Megumi Shida 1-8-1, Koura, Kanazawa-ku, Yokohama-shi Mitsubishi (72) Inventor Tadatoshi Ishigaki, 12 Nishikicho, Naka-ku, Yokohama-shi Mitsubishi Heavy Industries, Ltd.Yokohama Works, Ltd. F term (reference) 4D048 AA02 AA03 AA06 AC10 BA03X BA06X BA10X BA13X BA41X BA42X BB01 BD10 CA07 CB05 CC24 CC38 CC61 CD03 4D058 JA60 JA70 JB06 JB33 KA18 KA23 QA01 QA03 QA11 TA06

Claims (5)

[Claims] An exhaust gas inlet which is provided with a packed layer of catalyst particles inside a rotatable cylinder and opens in a direction substantially perpendicular to an axis of the cylinder and toward an outer peripheral surface of the cylinder. And an exhaust gas outlet, respectively, and while rotating the cylindrical body, the exhaust gas is guided from the exhaust gas inlet into the cylindrical body, brought into contact with the catalyst through a catalyst packed layer in the cylindrical body, and then led to the exhaust gas outlet. In the exhaust gas treatment device, the exhaust gas inlet, the exhaust gas outlet, and the cylindrical body may be configured such that a speed of the exhaust gas flowing from the exhaust gas inlet to the cylindrical body is higher than a speed of the exhaust gas flowing from the cylindrical body to the exhaust gas outlet. An exhaust gas treatment device characterized by being constituted. 2. The exhaust gas treatment device according to claim 1, wherein the exhaust gas passage area on the exhaust gas outlet side is larger than the exhaust gas passage area on the exhaust gas inlet side. 3. The cylindrical body is formed into an annular body composed of an outer cylinder and an inner cylinder each having a large number of exhaust gas passage holes, and the catalyst particles are formed in an annular space between the outer cylinder and the inner cylinder. Is formed, and after the exhaust gas passing through the exhaust gas inlet and passing through the packed layer on one side in the cylinder is decelerated in an internal passage formed inside the inner cylinder, the other side in the cylinder is The exhaust gas treatment device according to claim 1, wherein the exhaust gas treatment device is configured to be guided to the exhaust gas outlet side through a packed bed of (1). 4. The exhaust gas inlet and the exhaust gas outlet are provided at axially symmetric positions with respect to the rotation center of the cylindrical body, and the dust in the packing layer in the cylindrical body is provided at a circumferentially intermediate portion between the exhaust gas inlet and the exhaust gas outlet. 4. A regenerator for removing the catalyst and regenerating the catalyst is provided, wherein the annular tubular body is configured to circulate from the exhaust gas outlet side to the exhaust gas inlet side via the regenerator. Exhaust gas treatment equipment. 5. A dust discharge port for discharging dust treated by the regenerator at an outlet of the regenerator.
An exhaust gas treatment apparatus according to claim 1.