KR102659568B1 - Metal Catalyst Filter for Nitrogen Oxide Reduction Device - Google Patents

Abstract

The present invention is a metal catalyst for a nitrogen oxide reduction device that does not undergo thermal deformation due to high-temperature exhaust gas even when used for a long period of time, so no damage such as cracks occurs, and can be reused by cleaning the catalyst plate after use for a certain period of time and then coating it with a reducing agent. It's about reduction filters.
A metal catalytic reduction filter for a nitrogen oxide reduction device according to the present invention to solve the above problems includes a box-shaped case formed in a square frame shape with open front and rear sides; a plurality of first catalyst plates formed in a flat shape and horizontally inserted through the open front of the case; It includes a zigzag-shaped second catalyst plate installed between the plurality of first catalyst plates, wherein the first and second catalyst plates are made of stainless steel and are made of a mesh network with holes of a predetermined size, and the first catalyst plate Catalyst plates 1 and 2 are characterized in that they are immersed in a water tank containing a liquid reducing agent for a predetermined period of time and then dried to form a first reducing agent coating layer in which the reducing agent is coated to a predetermined thickness on the surface.

Description

Metal Catalyst Filter for Nitrogen Oxide Reduction Device}

The present invention relates to a metal catalytic reduction filter for a nitrogen oxide reduction device, and more specifically, to a metal catalytic reduction filter for a nitrogen oxide reduction device installed to reduce nitrogen oxides contained in exhaust gas.

In general, nitrogen oxide reduction devices are installed in the exhaust pipes of various industrial facilities such as stacks or internal combustion engines to remove pollutants such as nitrogen oxides discharged with exhaust gas. These nitrogen oxide reduction devices include a catalyst member containing a reducing agent. It is installed so that the exhaust gas passes through the catalyst member and is discharged, and through this, nitrogen oxides and the reducing agent of the catalyst member cause a catalytic reduction reaction to remove nitrogen oxides from the exhaust gas.

As a prior art for the above purpose, a nitrogen oxide reduction device (hereinafter referred to as 'patent document') disclosed in Patent Registration No. 2183062.

The patent document includes a housing to which an inlet pipe connected to an exhaust gas discharge device, an discharge pipe, and a bypass pipe connected to the discharge pipe are each connected; and a nitrogen oxide removal unit provided inside the housing and removing nitrogen oxides from the exhaust gas, wherein the housing allows the exhaust gas flowing into the housing through the inlet pipe to bypass the nitrogen oxide removal unit. It is configured to flow into the discharge pipe after nitrogen oxides are removed while flowing through the bypass pipe or passing through the nitrogen oxide removal unit. A first valve is provided inside the housing, and when the first valve is closed, the nitrogen oxides flow into the housing. The exhausted gas bypasses the nitrogen oxide removal unit and flows into the bypass pipe. When the first valve is opened, the exhaust gas flowing into the housing flows into the nitrogen oxide removal unit and is operated by the first valve. The inside of the housing is divided into a first area where the inlet pipe and the bypass pipe are connected, and a second area where the nitrogen oxide removal unit is provided and the discharge pipe is connected. The bypass pipe opens when the first valve is closed. A second valve is provided that closes when opened, and the discharge pipe is provided with a third valve that closes when the first valve is closed and opens when the first valve is opened. The nitrogen oxide removal unit removes nitrogen from the exhaust gas through a selective catalytic reduction reaction of nitrogen oxides by a reducing agent. To remove oxides, the nitrogen oxide removal unit includes a plurality of catalyst members containing catalysts, and a flow path through which exhaust gas flows is formed between the plurality of catalyst members, and one side of the flow path is opened and the other side is opened. The side is closed, and one side of the flow path adjacent to the flow path is closed and the other side is open.

However, the patent document states that nitrogen oxides are reduced and removed in the process of exhaust gas passing through a catalyst member (hereinafter referred to as 'catalyst filter'), but the conventional catalyst filter allows high-temperature exhaust gas to pass through a perforated plate made of synthetic resin. In the process, the catalytic filter is repeatedly thermally deformed, causing cracks or damage, which reduces the efficiency of reducing nitrogen oxides when used for a long period of time. In addition, maintenance costs increase because the expensive catalytic filter cannot be reused. There is a problem that a lot of environmental waste is generated in the process of disposing of used catalytic filters and at the same time, resources are wasted.

Therefore, there is a need to develop a catalytic filter for a nitrogen oxide reduction device with an improved structure so that the catalytic filter used in the nitrogen oxide removal (reduction) device can be reused, thereby reducing environmental waste and saving maintenance costs.

KR 10-2183062 B1 (2020. 11. 19.) KR 10-2249985 B1 (2021. 05. 03.) KR 10-1989111 B1 (2019. 06. 07.) KR 10-1828458 B1 (2018. 02. 06.)

The present invention was developed to solve the problems of the conventional catalytic filter for nitrogen oxide reduction devices as described above. The problem that the present invention aims to solve is that thermal deformation due to high-temperature exhaust gas does not occur even when used for a long period of time, such as cracks, etc. To provide a metal catalyst reduction filter for a nitrogen oxide reduction device that does not cause damage and can be reused by cleaning the catalyst plate after use for a certain period of time and then coating it with a reducing agent.

A metal catalytic reduction filter for a nitrogen oxide reduction device according to the present invention to solve the above problems includes a box-shaped case formed in a square frame shape with open front and rear sides; a plurality of first catalyst plates formed in a flat shape and horizontally inserted through the open front of the case; It includes a zigzag-shaped second catalyst plate installed between the plurality of first catalyst plates, wherein the first and second catalyst plates are made of stainless steel and are made of a mesh network with holes of a predetermined size, and the first catalyst plate Catalyst plates 1 and 2 are characterized in that they are immersed in a water tank containing a liquid reducing agent for a predetermined period of time and then dried to form a first reducing agent coating layer in which the reducing agent is coated to a predetermined thickness on the surface.

Another feature of the present invention is that the first and second catalyst plates are immersed in a water bath containing the reducing agent and then heated to a predetermined temperature and fired.

Additionally, another feature of the present invention is that the first and second catalyst plates are fired under temperature conditions of 350 to 550°C.

In addition, another feature of the reducing agent of the present invention is that ammonia water or urea water is used.

Another feature of the present invention is that the first and second catalyst plates are stacked alternately up and down inside the case, and then are individually slid out toward the front to be replaced or cleaned.

According to the present invention, since the metal catalyst reduction filter for the nitrogen oxide reduction device is made of stainless steel, it is not easily deformed or damaged by external force and has the advantage of being usable for a long period of time.

In addition, the filter is made of stainless steel and then coated with a reducing agent on the surface. When the reducing agent disappears due to long-term use, it can be reused by re-coating the reducing agent on the filter, which is used to reduce nitrogen oxides. It has the advantage of saving resources while reducing filter maintenance and replacement costs.

In addition, there is an advantage in that fine dust in the air passing through the metal catalyst reduction filter adheres to the metal catalyst plate, thereby reducing fine dust in the air emitted.

1 is a perspective view showing an example of a metal catalytic reduction filter for a nitrogen oxide reduction device according to the present invention.
Figure 2 is a front view showing an example of a metal catalytic reduction filter for a nitrogen oxide reduction device according to the present invention.
Figure 3 is a plan view showing an example of a metal catalytic reduction filter for a nitrogen oxide reduction device according to the present invention.
4 to 6 are diagrams showing examples of the first and second catalyst plates of the metal catalytic reduction filter for the nitrogen oxide reduction device according to the present invention.
Figure 7 is a view showing an example in which a second reducing agent coating layer is formed according to the present invention.
Figure 8 is a diagram showing another example in which a second catalyst plate according to the present invention is installed.

Hereinafter, the present invention will be described in detail according to the accompanying drawings showing preferred embodiments.

The present invention is a metal catalyst for a nitrogen oxide reduction device that does not undergo thermal deformation due to high-temperature exhaust gas even when used for a long period of time, so no damage such as cracks occurs, and can be reused by cleaning the catalyst plate after use for a certain period of time and then coating it with a reducing agent. The present invention is intended to provide a reduction filter, and includes a case 10, a first catalyst plate 20, and a second catalyst plate 30 as shown in FIGS. 1 and 2.

Hereinafter, for convenience of explanation, one side of the case 10 through which the exhaust gas flows will be referred to as 'front' or 'front', and the side through which the exhaust gas passes through the case 10 and discharged will be referred to as 'rear' or 'front'. This is explained by referring to it as ‘the back’.

The case 10 is configured to maintain the first and second catalyst plates 20 and 30, which will be described later, in a fixed position by stacking them vertically.

As shown in FIGS. 1 and 2, the case 10 is shaped like a square frame with open front and back sides and is formed to have a predetermined length in the front-back direction.

Additionally, the case 10 may be made of stainless steel with excellent corrosion resistance and heat resistance so as not to corrode even when in contact with exhaust gas for a long period of time.

And, as shown in FIG. 3, on the rear side of the case 10, locking protrusions 11 of a predetermined width are formed on both sides to face each other and protrude in the vertical direction, and these protruding protrusions 11 are used to When the catalyst plates 1 and 2 (20, 30) are slidably inserted from the front of the case (10), they are supported and fixed without falling to the back of the case (10).

At this time, the locking protrusion 11 may be formed to be inclined at an angle A of 30 to 60° toward the rear so as not to impede the flow of exhaust gas passing through the case 10, and through this, the Instead of the exhaust gas hitting the trap 11 and forming a vortex, the discharge direction is naturally guided along the inclined surface and is discharged smoothly without vortex.

Meanwhile, a reducing agent may be coated on the inner surface of the case 10 to a predetermined thickness, and when the exhaust gas comes into contact with the inner surface of the case 10 in the process of passing through the first and second catalyst plates 20 and 30, , a reduction catalytic reaction between the coated reducing agent and nitrogen oxides occurs, further increasing the reduction (removal) efficiency of nitrogen oxides.

In addition, both sides of the case 10 may be bent in a "ㄷ" shape at a predetermined interval to form seating grooves (not shown), and both ends of the first catalyst plate 20 may be inserted through these seating grooves. It can be configured to be seated horizontally, which makes it easier to replace the first and second catalyst plates 20 and 30 by sliding them into the inside of the case 10 or separating them individually.

The first catalyst plate 20 supports the second catalyst plate 30 so that the second catalyst plates 30, which will be described later, can be stacked up and down without overlapping each other, and at the same time, exhaust gas passes through to catalyze nitrogen oxides. It is a composition that reduces through.

This first catalyst plate 20 is formed in the shape of a stainless steel plate with a predetermined thickness, and a plurality of through holes (no reference numerals) are formed on the stainless steel plate at predetermined intervals to allow exhaust gas to pass through.

At this time, instead of forming a through hole in a stainless steel plate, it may be composed of a stainless steel mesh network manufactured to have a predetermined mesh size using stainless steel metal thread.

In addition, the first catalyst plate 20 may have a thickness T1 equal to or relatively thick as the thickness T2 of the second catalyst plate 30, through which the exhaust gas of the first catalyst plate 20 may be formed. In the process of passing through the through hole, it comes into more reliable contact with the reducing agent coated on the inner side of the through hole, thereby inducing a catalytic reaction.

In addition, the strength of the first catalyst plate 20 is improved to prevent deformation due to the load of the second catalyst plate 30 or thermal deformation due to high temperature exhaust gas, and as a result, the first and second catalyst plates 20 and 30 ) is prevented from occurring between the first and second catalyst plates (20, 30), thereby reducing noise and vibration caused by the first and second catalyst plates (20, 30) randomly shaking during the process of exhaust gas passing through the first and second catalyst plates (20, 30). do.

As shown in FIGS. 1 and 2, the first catalyst plate 20 is slidably inserted from the front of the case 10 inward, and a plurality of first catalyst plates 20 are installed horizontally at predetermined intervals up and down.

The second catalyst plate 30 is installed between a plurality of first catalyst plates 20 installed at predetermined intervals up and down inside the case 10 and allows exhaust gas to pass through the inside of the case 10 and be discharged. It is a composition that forms.

Like the first catalyst plate 20, the second catalyst plate 30 is made of stainless steel with a predetermined thickness and has a plurality of through holes (no reference numerals) formed at predetermined intervals to allow exhaust gas to pass through, or Alternatively, it may be composed of a stainless steel mesh network manufactured to have a predetermined mesh size using metal thread made of stainless steel.

And, as shown in FIG. 4, the second catalyst plate 30 is formed in a zigzag shape with alternating peaks and valleys, and through this, the second catalyst plate 30 is formed between the upper and lower pair of first catalyst plates 20. ) is inserted, an air passage of a predetermined height (H) is formed by the second catalyst plate 30.

At this time, the second catalyst plate 30 may be formed in a wavy shape instead of being formed in a zigzag shape. Alternatively, the second catalyst plate 30 may be formed at a predetermined height between the pair of first catalyst plates 20 such as a zigzag shape or a wave shape. It may be changed into various shapes that can form the air passage of (H).

On the other hand, when the first and second catalyst plates 20 and 30 are composed of a mesh network using stainless steel metal thread, the edge of the mesh network is caught in the hole of another adjacent catalyst plate, causing the catalyst plate to slide into the inside of the case 10. In order to prevent them from sliding easily when inserted or taken out, a rectangular frame-shaped stainless steel border (not shown) surrounding the edges of the first and second catalyst plates 20 and 30 may be further provided.

The second catalyst plate 30 configured as above forms a passage so that the exhaust gas passes between the first catalyst plate 20 and is discharged to the rear of the case 10, and the exhaust gas flowing along this passage naturally flows into the second catalyst plate 20. The reducing agent (first and second reducing agent coating layers (C, Nitrogen oxides in the exhaust gas are reduced and removed (reduced) by a catalytic reaction with C').

In addition, when the reducing agent in the first and second catalyst plates 20 and 30, which are slidably inserted and installed inside the case 10, disappears and the removal efficiency of nitrogen oxides decreases, or when the case needs to be replaced after being used for a certain period of time, The first and second catalyst plates 20 and 30 can be easily replaced by taking them out from the inside of (10) toward the front and slidingly inserting other first and second catalyst plates 20 and 30 prepared in advance.

And the used first and second catalyst plates 20 and 30 are reused by washing the surfaces and then coating them with a reducing agent again.

Meanwhile, the surfaces of the first and second catalyst plates (20, 30) are coated with a reducing agent so that nitrogen oxides in the exhaust gas that come into contact with the surfaces of the first and second catalyst plates (20, 30) are reduced by a catalytic reaction. , it needs to be configured so that the coating reducing agent does not easily fall off from the first and second catalyst plates 20 and 30.

For this purpose, the present invention involves immersing the first and second catalyst plates (20, 30) prepared in advance in a water tank containing a liquid reducing agent selected from among ammonia water, urea water, and various known reducing agents for a predetermined period of time, and then removing them from the water tank. Allow the first and second catalyst plates 20 and 30 to naturally dry at room temperature.

Then, it is put into a sintering furnace under a temperature condition of 350 to 550°C, heated and sintered for a predetermined time, and then discharged from the furnace and naturally dried at room temperature, forming the first and second reducing agent coating layers (C, C'). This can be formed.

At this time, after the first reducing agent coating layer (C) is formed entirely on the first and second catalyst plates 20 and 30, the second reducing agent coating layer (C') is formed by repeating the above process to form the first and second reducing agent coating layers (C') as shown in FIG. 7. 2 A second reducing agent coating layer (C') of a predetermined thickness is further formed inside the through hole of the catalyst plate (20, 30), and in this way, a second reducing agent coating layer (C') is further formed in the through hole. As a result, the diameter of the through hole becomes relatively small, and as the exhaust gas passes through the smaller through hole, the exhaust gas naturally flows in fine distribution, and at the same time, the flow rate is reduced and the first and second reducing agent coating layers ( As it comes into sufficient contact with C, C'), the exhaust gas catalytic reaction is further ensured.

Meanwhile, above, it was shown and explained that only a passage through which exhaust gas flows through the second catalyst plate 30 is formed, but unlike this, as shown in FIG. 8, the zigzag shape of the second catalyst plate 30 is used in the case ( 10) can be installed diagonally at an angle of 45° to the front and rear longitudinal direction, and through this, the exhaust gas flowing into the front of the second catalyst plate 30 must be discharged toward the rear of the case 10. , 2 It may be configured to pass through the through hole of the catalyst plates 20, 30, and through this, the nitrogen oxides contained in the exhaust gas are induced to be reduced through a more reliable catalytic reaction through the reducing agent.

In addition, in the above, the first catalyst plate 20 and the second catalyst plate 30 are shown and described as being separated from each other and stacked alternately, but unlike this, the first and second catalyst plates 20 and 30 are in contact with each other. The parts can be manufactured integrally through spot welding, and a plurality of catalyst plates manufactured in this way can be stacked top and bottom and stored in the case 10, or the first and second catalyst plates 20 and 30 can be separated into one set. It can be changed to be replaced.

As explained above, in the present invention, the metal catalytic reduction filter for the nitrogen oxide reduction device is made of stainless steel, so it is not easily deformed or damaged by external force and can be used for a long period of time.

In addition, the filter is made of stainless steel and then coated with a reducing agent on the surface. When the reducing agent disappears due to long-term use, it can be reused by re-coating the reducing agent on the filter, which is used to reduce nitrogen oxides. Filter maintenance and replacement costs can be reduced while resources are saved.

In addition, fine dust in the air passing through the metal catalyst reduction filter attaches to the metal catalyst plate, thereby reducing fine dust in the air emitted.

Above, for convenience of explanation, reference numerals and names have been given to the drawings showing preferred embodiments and the configurations shown in the drawings. However, this is an embodiment according to the present invention, and the shapes shown in the drawings and the names given are The scope of the rights should not be construed as limited, and changes to various shapes that can be predicted from the description of the invention and simple substitution to a configuration that performs the same function are within the scope of changes that can be easily carried out by a person skilled in the art. You will see this as extremely self-evident.

10: case 11; stumbling block
20: first catalyst plate 30: second catalyst plate
A: Angle of the locking step C: First reducing agent coating layer
C: Second reducing agent coating layer H: Height of second catalyst plate
T1: Thickness of the first catalyst plate T2: Thickness of the second catalyst plate

Claims (5)

In the catalytic reduction filter for reducing nitrogen oxides contained in exhaust gas,
The catalytic reduction filter is,
A box-shaped case (10) formed in the shape of a square frame with open front and rear sides;
A plurality of first catalyst plates 20 formed in a flat shape and horizontally inserted through the open front of the case 10;
A zigzag-shaped second catalyst plate (30) installed between the plurality of first catalyst plates (20);
Including,
The first and second catalyst plates 20 and 30,
It is made of stainless steel and consists of a mesh network with holes of a predetermined size,
The first and second catalyst plates 20 and 30,
It is immersed in a water tank containing a liquid reducing agent for a predetermined period of time, and then dried to form a first reducing agent coating layer (C) in which the reducing agent is coated to a predetermined thickness on the surface,
The first and second catalyst plates 20 and 30,
After being immersed in a water bath containing the reducing agent, it is heated and fired under temperature conditions of 350 to 550°C,
In the case 10,
Towards the rear, locking protrusions 11 of a predetermined width are formed to face each other and protrude in the vertical direction on both sides so that the first and second catalyst plates 20 and 30 are supported without being removed, and the locking protrusions 11 are positioned at the rear. It is formed inclined at an angle (A) of 30 to 60° toward the side, so that the exhaust gas passing through the inside of the case 10 hits the stopping 11 and forms a vortex, but the discharge direction is naturally along the inclined surface. Be guided,
On the inner side of the case 10,
The reducing agent is coated to a predetermined thickness, and as the exhaust gas passes through the first and second catalyst plates 20 and 30, it comes in contact with the inner surface of the case 10, causing a reduction catalytic reaction between nitrogen oxides and the reducing agent, producing nitrogen oxides. to be removed,
On both sides of the interior of the case 10,
A seating groove is formed by bending in a "ㄷ" shape at a predetermined interval, and the first and second catalyst plates 20 and 30 are individually slidably inserted into the case 10 or separated through the seating groove. A metal catalytic reduction filter for a nitrogen oxide reduction device, characterized in that it is configured to be replaced.
delete delete In claim 1,
The reducing agent is,
A metal catalyst reduction filter for a nitrogen oxide reduction device, characterized in that ammonia water or urea water is used.
In claim 1,
The first and second catalyst plates 20 and 30,
A metal catalytic reduction filter for a nitrogen oxide reduction device, characterized in that it is used by being stacked alternately up and down inside the case 10, and then is individually slid toward the front to be replaced or cleaned.

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