JP2018091589A - Nitrogen-containing waste liquid incinerator and denitration method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nitrogen-containing waste liquid incinerator capable of efficiently incinerating nitrogen-containing waste liquid and enabling enlargement, and a denitration method thereof.SOLUTION: A nitrogen-containing waste liquid incinerator includes a lateral furnace body 10 whose inner surface is formed by bricks 11 and extension direction is a lateral direction, and a partition structure 20 configured to partition the inside of the furnace body 10 into an upstream side combustion chamber CB and a downstream side denitration chamber CD. The partition structure 20 has a plurality of partition plates 21, 22 that is arrayed in the extension direction and at a part of side edge of which an opening part 219, 229 is formed. The partition plates 21, 22 are formed so that the adjacent opening parts 219, 229 are opposite to each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a nitrogen-containing waste liquid combustion furnace and a denitration method thereof.

Conventionally, incineration of nitrogen-containing waste liquid has been performed. Nitrogen oxides are generated during incineration of nitrogen-containing waste liquid. In contrast, an ammonium source compound is added after the incineration process to reduce nitrogen oxides by denitration reaction.
In Patent Document 1, the inside of a nitrogen-containing waste liquid combustion furnace is divided into an upstream primary chamber and a downstream secondary chamber, and additional air is blown into the secondary chamber. Further, ammonia is blown into the secondary chamber.
In Patent Document 2, a part of the nitrogen-containing waste liquid to be incinerated is blown for denitration reaction in the secondary chamber.

JP-A-8-233245 Japanese Patent Laid-Open No. 7-112116

In the nitrogen-containing waste liquid combustion furnace of Patent Document 1, the furnace body has a vertical cylindrical shape extending in the vertical direction, and a partition plate that divides the inside of the furnace into a primary chamber and a secondary chamber is disposed horizontally, A hole communicating with the next chamber was formed at the center of the partition plate.
In such a furnace structure, it is easy for combustion gas from the primary chamber to be blown into the secondary chamber from the central hole of the partition plate and reach the outlet of the secondary chamber as it is. There was a possibility that it could not be used effectively.
When such a state in the furnace occurs, the denitration reaction is not performed sufficiently efficiently, and nitrogen oxides that are not sufficiently processed may be discharged. When the nitrogen-containing waste liquid blown into the secondary chamber is increased to supplement the denitration reaction, excess nitrogen-containing waste liquid may be discharged out of the furnace.

  On the other hand, when the nitrogen-containing waste liquid combustion furnace is enlarged, a fireproof material such as brick is used for the partition plate. However, in a vertical nitrogen-containing waste liquid combustion furnace, it is difficult to form a partition plate extending in the horizontal direction with bricks, or in order to give the partition plate a margin of strength, the material increases and the cost increases. There is a possibility of connection.

  An object of the present invention is to provide a nitrogen-containing waste liquid combustion furnace that can efficiently incinerate a nitrogen-containing waste liquid and that can be enlarged, and a denitration method thereof.

  The nitrogen-containing waste liquid combustion furnace of the present invention includes a horizontal furnace body whose inner surface is formed of a refractory material and whose extending direction is a lateral direction, and the interior of the furnace body is divided into an upstream combustion chamber and a downstream denitration chamber. A partition structure for partitioning, and the partition structure has an opening that communicates the upstream side and the downstream side of the partition structure in at least a part of the edge along the inner surface of the furnace body. It is characterized by.

In the present invention, a combustion burner can be installed at the upstream end of the combustion chamber. The burner can blow air together with fuel, and for example, coke oven gas can be used as combustion. In the burner, a part of the nitrogen-containing waste liquid to be treated may be blown as fuel. The nitrogen-containing waste liquid to be treated is mainly blown into the combustion chamber downstream from the burner.
In the present invention, a part of the nitrogen-containing waste liquid to be treated is blown into the upstream side of the denitration chamber (downstream side of the partition structure) for denitration.

In the present invention, the interior of the furnace is partitioned into a combustion chamber and a denitration chamber by the partition structure. In the partition structure, the upstream side gas can be passed to the downstream side through the opening.
The opening is not formed at the center of the furnace body but at least at a part of the edge along the inner surface of the furnace body. For this reason, the gas that has flowed through the inside of the combustion chamber to the full extent in the furnace is a biased flow that concentrates on the edge where the opening is formed when passing through the partition structure. The gas that has passed through the partitioning structure diffuses again and flows all the way into the furnace of the denitration chamber from a state where it is biased toward the edge where the opening is formed.

Thus, in the present invention, the gas passing through the partition structure is diffused again after being throttled at the opening. In addition, in the partition structure, the opening is biased toward the edge rather than the center of the furnace body, so the flow of gas passing through the opening is bent and stays in the denitration chamber when it diffuses again in the denitration chamber. It spreads to the corner which is easy to do, and the space in the furnace body can be used effectively.
Therefore, the two-stage combustion in the denitration chamber is efficiently performed, and the incineration treatment of the nitrogen-containing waste liquid as the nitrogen-containing waste liquid combustion furnace can be efficiently performed.
On the other hand, in this invention, it is suitable for the enlargement of a nitrogen-containing waste liquid combustion furnace by setting it as the horizontal type | mold furnace body in which an inner surface is formed with a brick and the extending | stretching direction is a horizontal direction. In particular, in the partition structure, when the partition plate is formed, the bricks can be stacked in the shape of a vertical wall, respectively, and it is easy to ensure the strength, which is also suitable for increasing the size.

  In the nitrogen-containing waste liquid combustion furnace according to the present invention, the partition structure has a plurality of partition plates arranged in the extending direction, and the adjacent partition plates have each of the openings extending in the furnace body. In the cross-sectional shape in the direction crossing the direction, it is preferably formed in different regions.

In the present invention, openings are respectively formed in the plurality of partition plates, and the gas passing through the partition structure sequentially passes through the openings of the plurality of partition plates. That is, every time it passes through each partition plate, the concentration and diffusion of gas through each opening is repeated.
Furthermore, each opening part of each adjacent partition plate is a mutually different area | region, ie, a non-overlapping area | region, is made into the position which shifted | deviated to the extending | stretching direction which is a flow direction mutually, and is biased and arrange | positioned at the edge. For this reason, the flow of gas that passes through each partition plate is routed to the opening at a different position for each partition plate, and as a result, the gas undergoes a stirring effect and flows while being diffused throughout the cross-sectional shape in the furnace. can do.
In the present invention, the number of partition plates installed in the partition structure may be one, two, or three or more. The opening of a partition plate should just be formed in the edge of at least one part partition plate. For example, two or more partition plates can be alternately formed with openings on the opposite side. Further, an opening may be formed at the edge of some partition plates, and an opening may be formed at the center of other partition plates.

  In the nitrogen-containing waste liquid combustion furnace of the present invention, it is preferable that the plurality of partition plates have the opening portions adjacent to each other on opposite sides across the central portion of the cross-sectional shape.

In the present invention, the opening is preferably the farthest part of the partition plate between adjacent ones, and is formed at opposite edges of the partition plate, at both ends in the diametrical direction if the partition plate is circular. do it. For example, the opening can be on the upper and lower sides of the partition plate, on the right and left sides of the partition plate, or on the upper right side and lower left side of the partition plate.
When two partition plates are installed, an opening may be formed above the upstream partition plate, and an opening may be formed below the downstream partition plate. Alternatively, the opening may be formed on the lower side of the upstream partition plate and the opening may be formed on the upper side of the downstream partition plate.
When three partition plates are installed, an opening is formed above the first partition plate, an opening is formed below the second partition plate, and an opening is formed above the third partition plate. do it. Alternatively, the opening may be formed below the first partition plate, the opening may be formed above the second partition plate, and the opening may be formed below the third partition plate.

  In the present invention, openings that are opposite to each other are alternately formed in the plurality of partition plates, and the passing gas forms a flow that is bent in a zigzag shape over the entire inner diameter direction of the furnace body. For this reason, the gas that has flowed into the denitration chamber diffuses into the denitration chamber, and the space can be used effectively.

  In the nitrogen-containing waste liquid combustion furnace according to the present invention, the opening is formed in an upper part or a lower part of the partition plate, and the partition plate in which the opening is formed in an upper part is an upper edge of a wall body that partitions the furnace body It is preferable that the partition plate in which the opening is formed in the lower part is formed in an arch shape at the lower edge of the wall body that partitions the furnace body.

In the present invention, an arch-shaped brickwork is formed inside the furnace body, and bricks are stacked thereon to form a wall body, whereby a partition plate having an opening on the lower side of the arch-shaped lower edge is formed. It can be formed easily.
Moreover, the partition plate which has an opening part above a horizontal upper edge can be easily formed by laminating | stacking a brick sequentially from the lower surface inside a furnace body, and forming a wall body.

  In the nitrogen-containing waste liquid combustion furnace of the present invention, the opening of one of the partition plates is formed in a slit shape from the inner surface of the furnace body to the inner surface on the opposite side of the furnace body, Of the plurality of partition plates, the openings of the other partition plates are preferably formed on the sides along the inner surface of the furnace body on both sides of a region corresponding to the slit-shaped opening. .

In the present invention, for example, the slit-shaped opening can be arranged to extend in the vertical direction. Specifically, a partition plate having a slit-like opening at the center can be formed by stacking bricks in a sleeve wall shape on both sides of a predetermined position inside the furnace body. Moreover, the partition plate which has an opening part in both sides can be formed by piling bricks in the center of the inside of a furnace body in the shape of a monolith.
In the present invention, the gas that has passed through the slit-shaped opening in one partition plate branches and passes through the openings on both sides in the next partition plate. Or the gas which branched and passed to the opening part of both sides in one partition plate gathers again in the next partition plate, and passes the slit-shaped opening part. Even with such a configuration, the gas flowing into the denitration chamber can be diffused into the denitration chamber, and the space in the furnace can be used effectively.

  In the nitrogen-containing waste liquid combustion furnace of the present invention, an auxiliary partition plate for partitioning the interior of the furnace body is installed on the downstream side of the denitration chamber, and the auxiliary partition plate is the partition plate on the most downstream side of the partition structure. It is preferable that the opening is formed on the opposite side.

In the present invention, the gas flow that has passed through the partition structure flows into the denitration chamber from the opening of the partition plate on the most downstream side of the partition structure. Then, the gas flow passes through the opening of the auxiliary partition plate and is sent to the outlet of the denitration chamber. At this time, since the opening of the partition plate on the most downstream side of the partition structure and the opening of the auxiliary partition plate are opposite to each other, the gas flow crosses the inside of the denitration chamber up and down. Thus, the space can be used more effectively.
The auxiliary partition plate may be on the downstream side of the denitration waste liquid blowing position to be blown to the upstream side (downstream of the partition structure) of the denitration chamber, but the gas flow after diffusion is used for the denitration reaction. In order to ensure a sufficient space, it is desirable to be near the exit of the denitration chamber.

  In the nitrogen-containing waste liquid combustion furnace of the present invention, a sensor for detecting the nitrogen oxide concentration of the combustion gas denitrated in the denitration chamber, and a denitration blown into the denitration chamber based on the nitrogen oxide concentration detected by the sensor It is preferable to have a control device that adjusts the amount of waste liquid blown.

In the present invention, for example, the nitrogen oxide concentration of the combustion gas after the denitration treatment is detected at the outlet of the denitration chamber, and the amount of denitration waste liquid blown into the denitration chamber is adjusted based on the detected nitrogen oxide concentration. Therefore, denitration failure due to insufficient blowing amount can be prevented, and outflow of unburned waste liquid for denitration due to excessive blowing amount can be prevented.
When a part of the nitrogen-containing waste liquid is blown for denitration, the nitrogen oxide concentration in the combustion gas after the denitration treatment is preferably 45 ppm or more, and preferably 50 ppm or more. If the amount of nitrogen-containing waste liquid for denitration is increased so that the concentration of nitrogen oxides decreases, a part of it flows out of the furnace from the denitration chamber outlet, and ammonia or ammonium salt in the denitration chamber outlet gas. Will increase in concentration. Therefore, it is desirable to prevent the nitrogen oxide concentration from becoming excessively low at the exit of the denitration chamber. On the other hand, the nitrogen oxide concentration in the combustion gas after the denitration treatment is desirably 100 ppm or less. If this value is exceeded, sufficient effectiveness as a denitration treatment cannot be obtained.

  The denitration method for a nitrogen-containing waste liquid combustion furnace of the present invention uses a nitrogen-containing waste liquid combustion furnace having a combustion chamber and a denitration chamber, burns the nitrogen-containing waste liquid in the combustion chamber, and blows the nitrogen-containing waste liquid into the denitration chamber. The nitrogen gas concentration is detected in the combustion gas denitrated in the denitration chamber and the nitrogen-containing waste liquid is blown into the denitration chamber based on the detected nitrogen oxide concentration. It is characterized by adjusting the amount.

  In the denitration method of the nitrogen-containing waste liquid combustion furnace of the present invention, the nitrogen-containing waste liquid blown into the denitration chamber so that the nitrogen oxide concentration in the combustion gas denitrated in the denitration chamber is in the range of 45 ppm to 100 ppm. It is preferable to adjust the blowing amount.

  In the present invention, the nitrogen oxide concentration in the combustion gas after the denitration treatment is detected, and the amount of denitration waste liquid to be blown into the denitration chamber is adjusted based on the detected nitrogen oxide concentration. In addition, it is possible to prevent the denitration failure due to, and the outflow of unburned waste liquid for denitration due to excessive blowing amount.

  According to the present invention, it is possible to provide a nitrogen-containing waste liquid combustion furnace that can efficiently incinerate a nitrogen-containing waste liquid and that can be enlarged, and a denitration method thereof.

The longitudinal cross-sectional view which shows the furnace body of 1st Embodiment of this invention. Sectional drawing which shows the partition plate which has an opening part above the said 1st Embodiment. Sectional drawing which shows the partition plate which has an opening part below the said 1st Embodiment. The graph which shows the control reference | standard based on the nitrogen oxide density | concentration of the said 1st Embodiment. The plane sectional view showing the furnace object of a 2nd embodiment of the present invention. Sectional drawing which shows the partition plate which has the slit-shaped opening part of the said 1st Embodiment. Sectional drawing which shows the partition plate which has an opening part in the both sides of the said 1st Embodiment.

[First Embodiment]
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings.
In FIG. 1, a nitrogen-containing waste liquid combustion furnace 1 incinerates a nitrogen-containing waste liquid, and has a horizontal cylindrical furnace body 10 whose extending direction is a horizontal direction.
The furnace body 10 has an outer shell formed of an iron shell and a brick 11 as a refractory material on the inner surface. A partition structure 20 is installed in an intermediate portion (region CP) of the furnace body 10.
The interior of the furnace body 10 is partitioned by a partition structure 20 into an upstream (left side in FIG. 1) combustion chamber CB and a downstream (right side in FIG. 1) denitration chamber CD.

The furnace body 10 has a conical shape at the upstream end of the combustion chamber CB, and a combustion burner 30 is installed at the tip. The burner 30 includes a fuel nozzle 31, an air nozzle 32, and a combustion waste liquid nozzle 33.
Coke oven gas (COG), which is fuel, is blown from the fuel nozzle 31.
Air necessary for combustion is blown from the air nozzle 32.
A part of the nitrogen-containing waste liquid to be treated (10 to 40% of the nitrogen-containing waste liquid treated in the nitrogen-containing waste liquid combustion furnace 1) is blown from the combustion waste liquid nozzle 33 as fuel.
The burner 30 uses the coke oven gas from the fuel nozzle 31 and the nitrogen-containing waste liquid from the combustion waste liquid nozzle 33 as fuel, mixes it with the air from the air nozzle 32 and burns it, so that high-temperature gas is introduced into the combustion chamber CB. Can be supplied.

A main waste liquid nozzle 34 is connected to the furnace body 10 at a portion downstream of the burner 30 of the combustion chamber CB.
From the main waste liquid nozzle 34, most of the nitrogen-containing waste liquid to be treated (60 to 90% of the nitrogen-containing waste liquid treated in the nitrogen-containing waste liquid combustion furnace 1) is blown into the combustion chamber CB.
The nitrogen-containing waste liquid blown into the combustion chamber CB is incinerated by the high-temperature gas from the burner 30, and thermal NOx is generated simultaneously with the decomposition of ammonia contained in the waste liquid. .
The gas containing the waste liquid that has been incinerated passes through the partition structure 20 and is introduced into the denitration chamber CD.

A denitration waste liquid nozzle 35 is connected to the furnace body 10 upstream of the denitration chamber CD (downstream of the partition structure 20). An exhaust cylinder 12 is connected to the downstream side of the denitration chamber CD.
From the denitration waste liquid nozzle 35, in order to decompose and detoxify the thermal NOx by a denitration reaction, a part of the nitrogen-containing waste liquid to be treated containing ammonia (10 of the nitrogen-containing waste liquid to be treated in the nitrogen-containing waste liquid combustion furnace 1). % Or less) is blown into the denitration chamber CD.
The incinerated gas introduced into the denitration chamber CD is denitrated by the waste liquid from the denitration waste liquid nozzle 35 and discharged from the exhaust cylinder 12.

In this embodiment, the partition structure 20 is configured to include a plurality of partition plates 21 and 22 based on the present invention. The two partition plates 21 and 22 have a partition plate 21 on the upstream side and a partition plate 22 on the downstream side.
In addition, the partition structure 20 is not limited to a structure provided with a some partition plate, For example, it is good also as a structure provided with either one of the partition plates 21 and 22. FIG.

As shown also in FIG. 2, the partition plate 21 has a wall body 210 formed by stacking bricks on the bricks 11 at the lower part of the furnace body 10.
The upper edge 211 of the wall body 210 is horizontally formed at a position higher than the center of the furnace body 10.
An opening 219 is formed between the upper edge 211 and the brick 11 facing the upper edge 211.

As shown also in FIG. 3, the partition plate 22 is a wall body 220 formed by laying bricks in an arch shape between the bricks 11 on both sides at a position lower than the center of the furnace body 10 and placing the bricks thereon. Have
The lower edge 221 of the wall body 220 is the arch-shaped portion described above.
An opening 229 is formed between the lower edge 221 and the brick 11 facing the lower edge 221.

Accordingly, an opening 219 is formed in a part of the edge of the partition plate 21 (upper side of the circumference), and an opening 229 is formed in a part of the edge of the partition plate 22 (lower side of the circumference). The Thereby, as for the partition plates 21 and 22, the opening parts 219 and 229 of the adjacent things are formed in the mutually opposite side (upper side and lower side).
In such a partition structure 20, the gas from the combustion chamber CB first passes through the opening 219 on the upper side of the partition plate 21 and flows downward between the partition plates 21 and 22, and then on the lower side of the partition plate 22. Through the opening 229 and into the denitration chamber CD. As a result, the gas passing through the partition structure 20 forms a flow that is bent in a zigzag shape.

In the present embodiment, an auxiliary partition plate 23 that partitions the inside of the furnace body 10 is installed on the downstream side of the denitration chamber CD.
The auxiliary partition plate 23 has the same configuration as the partition plate 21 described above, and includes a wall body 230, an upper edge 231 and an opening 239 shown in FIG.
That is, the opening 239 of the auxiliary partition plate 23 has the opening 239 on the upper side opposite to the opening 229 (lower side) of the partition plate 22 which is the most downstream side of the partition structure 20.
As a result, the gas flow flowing into the denitration chamber CD flows from the lower side of the denitration chamber CD, crosses the interior of the denitration chamber CD upward, passes through the opening 239 on the upper side of the auxiliary partition plate 23, and the exhaust pipe 12 Thus, the inside of the denitration chamber CD can be used effectively.

In the present embodiment, the exhaust cylinder 12 is provided with a sensor 41 that detects the nitrogen oxide concentration of the passing gas. A detection signal of the sensor 41 is connected to the control device 40.
The control device 40 is connected to the fuel nozzle 31, the air nozzle 32, the combustion waste liquid nozzle 33, the main waste liquid nozzle 34 and the denitration waste liquid nozzle 35. In addition, the amount of waste liquid blown can be adjusted.

The control device 40 performs the following control.
The control device 40 detects the nitrogen oxide concentration in the exhaust pipe 12 that is the outlet of the denitration chamber CD by the sensor 41. Then, based on the detected nitrogen oxide concentration, the amount of blown air in the fuel nozzle 31, the air nozzle 32, the combustion waste liquid nozzle 33, the main waste liquid nozzle 34 and the denitration waste liquid nozzle 35, in particular, denitration that directly affects the denitration process. The amount of nitrogen-containing waste liquid blown from the waste liquid nozzle 35 is adjusted.

For example, if the amount of nitrogen-containing waste liquid blown from the denitration waste liquid nozzle 35 or the main waste liquid nozzle 34 is increased so that the nitrogen oxide concentration becomes low, a part of the nitrogen oxide waste liquid is unburned from the exit of the denitration chamber CD to the outside of the furnace. As a result, the ammonia or ammonium salt concentration in the outlet gas of the denitration chamber CD increases.
In order to prevent this, the control device 40 limits the amount of nitrogen-containing waste liquid blown so that the nitrogen oxide concentration does not become extremely low. As a reference for this restriction, the control device 40 adjusts the amount of nitrogen-containing waste liquid blown so that the nitrogen oxide concentration of the combustion gas at the outlet of the NOx removal chamber CD is 45 ppm or more, and preferably 50 ppm or more.
On the other hand, the control device 40 adjusts the nitrogen oxide concentration of the combustion gas at the outlet of the NOx removal chamber CD to be 100 ppm or less so that sufficient effectiveness can be obtained as the NOx removal treatment.

FIG. 4 shows the relationship between the NH ₃ concentration (vertical axis) related to ammonia or ammonium salt and the NOx concentration (horizontal axis) related to nitrogen oxide in the gas in the exit gas of the denitration chamber CD.
In FIG. 4, the NOx concentration is distributed in the range of 10 to 80 ppm. Among these, in the region where the NOx concentration exceeds 45 ppm, the NH ₃ concentration is 50 ppm or less. On the other hand, in the region where the NOx concentration is 45 ppm or less, the NH ₃ concentration may reach 130 to 400 ppm.

  In consideration of such a relationship, the control device 40 of this embodiment is used for denitration so that the nitrogen oxide concentration in the outlet gas of the denitration chamber CD is 45 ppm or more and 100 ppm or less, and at least 50 ppm or more and 100 ppm or less. The amount of nitrogen-containing waste liquid blown from the waste liquid nozzle 35 or the like is adjusted.

According to the present embodiment described above, the following effects can be obtained.
The nitrogen-containing waste liquid combustion furnace 1 of the embodiment can be incinerated by generating a high-temperature gas by the burner 30 in the combustion chamber CB and blowing a part of the nitrogen-containing waste liquid to be treated. Further, in the denitration chamber CD, a part of the nitrogen-containing waste liquid to be treated can be blown to perform denitration treatment of the gas incinerated in the combustion chamber CB.

  In the said embodiment, it is suitable for enlargement by making the furnace body 10 of the nitrogen-containing waste liquid combustion furnace 1 into a horizontal type | mold where the inner surface is formed with the brick 11, and the extending | stretching direction is a horizontal direction. In particular, in the partition structure 20, when the partition plates 21 and 22 are formed, the bricks can be stacked in the shape of vertical walls, respectively, and it is easy to ensure the strength, which is also suitable for increasing the size. is there.

In the said embodiment, in order to partition the inside of the furnace body 10 into combustion chamber CB and denitration chamber CD, the partition structure 20 which has the some partition plates 21 and 22 is used. In the partition plates 21 and 22, the openings 219 and 229 are alternately formed on the opposite sides (upper side and lower side), and the passing gas forms a flow that is bent in a zigzag shape. For this reason, the gas that has flowed into the denitration chamber CD diffuses into the denitration chamber CD, and the space can be used effectively.
Therefore, two-stage combustion is efficiently performed in the denitration chamber CD, and incineration of the nitrogen-containing waste liquid as the nitrogen-containing waste liquid combustion furnace 1 can be performed efficiently.

In the embodiment described above, the partition plate 21 having the opening 219 formed in the upper portion is formed such that the upper edge 211 of the wall body 210 partitioning the furnace body 10 is formed horizontally, and the partition plate 22 having the opening 229 formed in the lower portion is formed. The lower edge 221 of the wall body 220 that partitions the furnace body 10 is formed in an arch shape.
For this reason, in the partition plate 22, an arch-shaped brickwork is formed inside the furnace body 10, and a wall body 220 is formed by stacking bricks thereon, so that the lower side of the arch-shaped lower edge 221. The partition plate 22 having the opening 229 can be easily formed.
Moreover, the partition plate 21 having the opening 219 on the upper side of the horizontal upper edge 211 can be easily formed by sequentially stacking bricks horizontally from the lower surface inside the furnace body 10 to form the wall body 210. .

In the embodiment, the auxiliary partition plate 23 for partitioning the inside of the furnace body 10 is installed on the downstream side of the denitration chamber CD, and the auxiliary partition plate 23 is an opening 229 of the partition plate 22 on the most downstream side of the partition structure 20 ( An opening 239 is formed on the opposite side (upper side) to the lower side.
For this reason, the gas flow that has passed through the partition structure 20 flows into the denitration chamber CD from the opening 229 of the partition plate 22 on the most downstream side of the partition structure 20. Then, the gas flow passes through the opening 239 of the auxiliary partition plate 23 and is sent to the exhaust pipe 12 which is the outlet of the denitration chamber CD. At this time, the opening 229 of the partition plate 22 on the most downstream side of the partition structure 20 and the opening 239 of the auxiliary partition plate 23 are opposite to each other, so that the gas flow is inside the denitration chamber CD. The space can be used more effectively.
In particular, the auxiliary partition plate 23 of the present embodiment is in the vicinity of the outlet of the denitration chamber CD, and can sufficiently secure the volume from the partition structure 20 to the auxiliary partition plate 23, that is, a space for the denitration reaction. .

In the embodiment, the sensor 41 installed at the outlet of the NOx removal chamber CD to detect the NOx concentration in the gas after the NOx removal, and the NOx removal chamber CD based on the nitrogen oxide concentration detected by the sensor 41. And a control device 40 for adjusting the amount of denitration waste liquid to be blown.
Then, the nitrogen oxide concentration of the combustion gas after the denitration treatment is detected at the outlet of the denitration chamber CD, and the nitrogen oxide concentration in the outlet gas of the denitration chamber CD is 45 ppm or more based on the detected nitrogen oxide concentration. The amount of denitration waste liquid blown into the denitration chamber CD is adjusted so as to be 100 ppm or less, preferably 50 ppm or more and 100 ppm or less.
For this reason, in the denitration chamber CD of the nitrogen-containing waste liquid combustion furnace 1, it is possible to prevent denitration failure due to insufficient blowing amount, and to prevent outflow of unburned denitration waste liquid due to excessive blowing amount.

[Second Embodiment]
Next, 2nd Embodiment of this invention is described based on drawing.
Although this embodiment differs from the first embodiment in the partition structure 20, the furnace body 10, the burner 30 and the control device 40 are common. Therefore, description of these common configurations is omitted, and the partition structure 20A of the present embodiment will be described below.

FIG. 5 shows a horizontal cross-sectional shape of the furnace body 10 of the present embodiment.
The furnace body 10 has bricks 11 stretched on a substantially cylindrical inner surface, and is partitioned into an upstream combustion chamber CB and a downstream denitration chamber CD by a partition structure 20A installed in a region CP.
In the furnace body 10, as in the first embodiment described above, incineration is performed in the combustion chamber CB by generating high-temperature gas by the burner 30 and blowing part of the nitrogen-containing waste liquid to be processed. Further, in the denitration chamber CD, a portion of the nitrogen-containing waste liquid to be treated is blown to perform denitration treatment of the gas incinerated in the combustion chamber CB. The denitrated gas is discharged from the exhaust cylinder 12.

  In FIG. 5, the partition structure 20 </ b> A is configured to include a plurality of partition plates 24 and 25. The two partition plates 24 and 25 have a partition plate 23 on the upstream side and a partition plate 25 on the downstream side.

As shown also in FIG. 6, the partition plate 24 has a monolithic wall body 240 formed by stacking bricks on the brick 11 at the lower part of the furnace body 10.
Edges 241 on both sides of the wall body 240 are formed in a vertical direction, and a half-moon shaped opening 249 is formed between the bricks 11 on both sides of the furnace body 10 facing each edge 241. Yes.
As shown also in FIG. 7, the partition plate 25 has wall bodies 250 formed in a half-moon shape on both sides of the furnace body 10. The wall body 250 is formed in a sleeve wall shape in which bricks are fixed to the bricks 11 on both lower sides of the furnace body 10 and bricks are further stacked thereon and extend upward.
The inner edges 251 of the wall body 250 are each formed in a vertical direction and are arranged to face each other. A slit-like opening 259 extending from the bottom of the furnace body 10 to the ceiling is formed between the pair of end edges 251.

Here, the half-moon-shaped opening 249 formed in the partition plate 24 is similar to the half-moon-shaped wall body 250 of the partition plate 25, and these are arranged in regions overlapping each other.
The slit-shaped wall 240 formed in the partition plate 24 has a similar shape to the slit-shaped opening 259 formed in the partition plate 25, and these are arranged in regions that overlap each other.
As a result, in the adjacent partition plates 24 and 25, the respective openings 249 and 259 are formed in different regions in the cross-sectional shape in the direction intersecting with the extending direction of the furnace body 10.
In such a partition structure 20 </ b> A, the gas from the combustion chamber CB branches to both sides before the partition plate 24, passes through the openings 249, and merges again between the partition plates 24 and 25. Through the central opening 259 and into the denitration chamber CD. As a result, the gas passing through the partition structure 20 </ b> A forms a flow that is bent in a zigzag manner on both sides of the furnace body 10.

In the present embodiment, an auxiliary partition plate 26 that partitions the inside of the furnace body 10 is installed on the downstream side of the denitration chamber CD.
The auxiliary partition plate 26 has the same configuration as the partition plate 24 described above, and includes a wall 260, an upper edge 261, and a pair of openings 269 shown in FIG.
That is, the opening 269 of the auxiliary partition plate 26 is a different area from the opening 259 (center portion) of the partition plate 25 that is the most downstream side of the partition structure 20A.
As a result, the gas flow flowing into the denitration chamber CD flows from the central portion of the denitration chamber CD, spreads to both sides inside the denitration chamber CD, branches again before the auxiliary partition plate 26, and opens on both sides 269 respectively. As a result, they merge again and flow into the exhaust pipe 12, so that the inside of the denitration chamber CD can be used effectively.

In the present embodiment, the partition plates 24 and 25 and the auxiliary partition plate 26 form a flow in which the gas flowing in the furnace body 10 is bent in a zigzag manner on each side, and the gas flowing through the denitration chamber CD is supplied to the denitration chamber CD. It can be sufficiently diffused inside, and space can be used effectively.
Therefore, the same effect as that of the partition structure 20 of the first embodiment described above can also be obtained by the partition structure 20A of the present embodiment. The same effects as those described in the first embodiment can be obtained by the present embodiment with other common configurations.

[Other Embodiments]
Note that the present invention is not limited to the above-described embodiments, and modifications and the like within a scope in which the object of the present invention can be achieved are included in the present invention.
In the embodiment, two partition plates 21 and 22 are installed in the partition structure 20, and the openings 219 on the upper side of the partition plate 21 and the lower side of the partition plate 22 are alternately opposite to each other. A side opening 229 was formed.
On the other hand, the arrangement of the openings may be turned upside down like the opening on the lower side of the partition plate 21 and the opening on the upper side of the partition plate 22. At this time, it is desirable that the lower edge is arched in the lower opening.
Moreover, the arrangement | positioning which opposes not only up and down but left and right and another direction etc. may be sufficient, for example, the opening part of the upper right side toward the downstream of the partition plate 21, the opening part of the lower left side of the partition plate 22, etc. It can also be. Thus, a zigzag flow can be formed by making the openings of the respective partition plates alternately on the opposite side.

Furthermore, the number of partition plates installed in the partition structure 20 may be three or more. Even in this case, a zigzag flow is formed by forming the openings alternately on opposite sides. be able to.
In the present embodiment, the auxiliary partition plate 23 is provided in the vicinity of the outlet of the denitration chamber CD. However, the auxiliary partition plate 23 is disposed at the position of the auxiliary partition plate 23 upstream of the denitration chamber CD (downstream from the partition structure 20). As long as it is located downstream from the blowing position (the blowing position of the denitration waste liquid nozzle 35). However, in order for the gas flow after diffusion to ensure a sufficient space for the denitration reaction, it is desirable to be as close as possible to the exit of the denitration chamber CD.
The auxiliary partition plate 23 may also be two or more like the partition plates 21 and 22. Alternatively, the auxiliary partition plate 23 may be omitted when retention in the denitration chamber CD does not become a problem.

In the nitrogen-containing waste liquid combustion furnace 1 of the above embodiment, the furnace body 10 has a cylindrical shape, but may have an arbitrary cross-sectional shape such as a polygonal cylindrical shape or a rectangular cylindrical shape.
In the nitrogen-containing waste liquid combustion furnace 1 of the above embodiment, the refractory material is made of brick, but an amorphous refractory material (castable or the like) can also be adopted.
In the nitrogen-containing waste liquid combustion furnace 1 of the above embodiment, the combustion burner 30 includes a fuel nozzle 31, an air nozzle 32, and a combustion waste liquid nozzle 33, and further includes a main waste liquid nozzle 34 and a denitration waste liquid. The nozzle 35 is provided. However, the arrangement and number of these may be changed as appropriate.

In the above embodiment, the sensor 41 is provided at the outlet of the denitration chamber CD. However, if the nitrogen oxide concentration in the combustion gas after denitration can be detected, the sensor 41 is not limited to the outlet of the denitration chamber CD, and waste liquid incineration is performed. You may install in the duct of a post-furnace stage.
In the above-described embodiment, the control device 40 adjusts the amount of denitration waste liquid blown into the denitration chamber CD based on the nitrogen oxide concentration detected by the sensor 41. Not only that, but also the combustion waste liquid nozzle 33 and the main waste liquid nozzle 34 may be used.

In the above embodiment, the nitrogen-containing waste liquid to be treated in the nitrogen-containing waste liquid combustion furnace 1 is distributed to the combustion waste liquid nozzle 33 by 10 to 20%, the main waste liquid nozzle 34 by 80 to 90%, and the denitration waste liquid nozzle 35 by several%. However, these ratios may be changed as appropriate.
Further, the content and source of the nitrogen-containing waste liquid to be treated are not particularly limited.
In the above embodiment, coke oven gas (COG) is used as the main fuel of the burner 30, but other fuels may be used.

  The present invention can be used in a nitrogen-containing waste liquid combustion furnace and a denitration method thereof.

  DESCRIPTION OF SYMBOLS 1 ... Nitrogen-containing waste liquid combustion furnace, 10 ... Furnace body, 11 ... Brick, 12 ... Exhaust pipe, 20 ... Partition structure, 21 ... Partition plate, 210 ... Wall body, 211 ... Upper edge, 219 ... Opening part, 22 ... Partition Plate, 220 ... Wall body, 221 ... Lower edge, 229 ... Opening, 23 ... Auxiliary partition plate, 230 ... Wall body, 231 ... Upper edge, 239 ... Opening, 24 ... Partition plate, 240 ... Wall body, 241 ... Edges, 249... Openings, 25 .. Partition plates, 250... Walls, 251... Edges, 259 .. Openings, 26 .. Auxiliary partition plates, 260. ... burner, 31 ... fuel nozzle, 32 ... air nozzle, 33 ... combustion waste nozzle, 34 ... main waste nozzle, 35 ... denitration waste nozzle, 40 ... control device, 41 ... sensor, CB ... combustion chamber, CD ... denitration Chamber, CP ... Partition structure area.

Claims (9)

A horizontal furnace body whose inner surface is formed of a refractory material and the extending direction is a lateral direction, and a partition structure that partitions the interior of the furnace body into an upstream combustion chamber and a downstream denitration chamber,
The nitrogen-containing waste liquid combustion characterized in that the partition structure is formed with an opening communicating with the upstream side and the downstream side of the partition structure in at least a part of the edge along the inner surface of the furnace body Furnace. In the nitrogen-containing waste liquid combustion furnace according to claim 1,
The partition structure has a plurality of partition plates arranged in the extending direction,
The nitrogen-containing waste liquid combustion furnace, wherein each of the adjacent partition plates is formed in a different region in a cross-sectional shape in a direction intersecting the extending direction of the furnace body. In the nitrogen-containing waste liquid combustion furnace according to claim 2,
The nitrogen-containing waste liquid combustion furnace characterized in that the plurality of partition plates are formed such that the openings of adjacent ones are opposite to each other across the center of the cross-sectional shape. In the nitrogen-containing waste liquid combustion furnace according to claim 3,
The opening is formed in the upper or lower part of the partition plate,
The partition plate in which the opening is formed in the upper part, the upper edge of the wall body that partitions the furnace body is formed horizontally,
The nitrogen-containing waste liquid combustion furnace characterized in that the partition plate, in which the opening is formed in the lower part, has an arched lower edge of the wall body that partitions the furnace body. In the nitrogen-containing waste liquid combustion furnace according to claim 2,
The opening of one of the plurality of partition plates is formed in a slit shape from the inner surface of the furnace body to the inner surface on the opposite side of the furnace body,
Of the plurality of partition plates, the openings of the other partition plates are formed at the edges along the inner surface of the furnace body on both sides of a region corresponding to the slit-shaped openings. A nitrogen-containing waste liquid combustion furnace. In the nitrogen-containing waste liquid combustion furnace according to any one of claims 1 to 5,
On the downstream side of the denitration chamber, an auxiliary partition plate that partitions the interior of the furnace body is installed,
The nitrogen-containing waste liquid combustion furnace, wherein the auxiliary partition plate has the opening formed on the opposite side to the partition plate on the most downstream side of the partition structure. In the nitrogen-containing waste liquid combustion furnace according to any one of claims 1 to 6,
A sensor for detecting the nitrogen oxide concentration of the combustion gas denitrated in the denitration chamber;
A nitrogen-containing waste liquid combustion furnace comprising: a control device that adjusts the amount of denitration waste liquid blown into the denitration chamber based on the nitrogen oxide concentration detected by the sensor. Using a nitrogen-containing waste liquid combustion furnace having a combustion chamber and a denitration chamber,
Burning the nitrogen-containing waste liquid in the combustion chamber, blowing the nitrogen-containing waste liquid into the denitration chamber to perform denitration treatment of the combustion gas,
Nitrogen oxide concentration in the combustion gas denitrated in the denitration chamber is detected, and an amount of nitrogen-containing waste liquid blown into the denitration chamber is adjusted based on the detected nitrogen oxide concentration Denitration method for waste liquid combustion furnace. In the denitration method of the nitrogen-containing waste liquid combustion furnace according to claim 8,
A nitrogen-containing waste liquid that adjusts the amount of nitrogen-containing waste liquid blown into the denitration chamber so that the nitrogen oxide concentration in the combustion gas denitrated in the denitration chamber is in the range of 45 ppm to 100 ppm. Denitration method for combustion furnace.

Images