JP6746481B2 - Nitrogen-containing waste liquid combustion furnace and denitration method thereof - Google Patents

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. On the other hand, an ammonium source compound is added after the incineration process to reduce nitrogen oxides by denitration reaction.
In Patent Document 1, the interior of the 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, it is also practiced to blow ammonia into the secondary chamber.
In Patent Document 2, a part of the nitrogen-containing waste liquid to be incinerated is blown for the denitration reaction in the secondary chamber.

JP-A-8-233245 JP-A-7-112116

In the nitrogen-containing waste liquid combustion furnace of Patent Document 1, the furnace body has a vertical tubular shape extending in the vertical direction, and a partition plate for partitioning the inside of the furnace into a primary chamber and a secondary chamber is horizontally arranged, and the primary chamber and the secondary chamber A hole communicating with the next chamber was formed in the center of the partition plate.
In such a furnace structure, the combustion gas from the primary chamber is blown into the secondary chamber through the hole in the center of the partition plate, and it is easy to 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 may not be performed sufficiently efficiently, and nitrogen oxides that are not sufficiently treated may be discharged. When the amount of nitrogen-containing waste liquid blown into the secondary chamber to increase the denitration reaction is increased, excess nitrogen-containing waste liquid may be discharged outside the furnace.

On the other hand, when enlarging the nitrogen-containing waste liquid combustion furnace, a refractory material such as brick is used for the partition plate. However, in a vertical type nitrogen-containing waste liquid combustion furnace, it is difficult to form a partition plate that extends in the horizontal direction from bricks, or the partition plate has a strength margin, so the number of materials increases and the cost increases. There is a possibility of being connected.

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

The nitrogen-containing waste liquid combustion furnace of the present invention has a horizontal furnace body whose inner surface is formed of a refractory material and whose stretching direction is a lateral direction, and the inside of the furnace body is divided into an upstream combustion chamber and a downstream denitration chamber. And a partition structure, wherein the partition structure is formed with an opening that connects the upstream side and the downstream side of the partition structure to at least a part of the edge along the inner surface of the furnace body. Is characterized by.

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

According to the present invention, the partition structure divides the furnace into a combustion chamber and a denitration chamber. In the partition structure, the gas on the upstream side can be passed to the downstream side through the opening.
The opening is not formed in the central portion of the furnace body, but is formed in at least a part of the edge along the inner surface of the furnace body. Therefore, the gas that has spread inside the combustion chamber to the full extent inside 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 partition structure diffuses again into the furnace in the denitration chamber and flows from the state in which it is biased toward the edge where the opening is formed.

As described above, in the present invention, the gas passing through the partition structure is narrowed at the opening and then diffused again. In addition, in the partition structure, the opening is biased toward the edge of the furnace body rather than the center, so the flow of gas through the opening is bent and the denitration chamber stays when it is diffused again in the denitration chamber. The space inside the furnace can be effectively used by expanding to the corners where it is easy to do.
Therefore, the two-stage combustion is efficiently performed in the denitration chamber, and the incineration process of the nitrogen-containing waste liquid as the nitrogen-containing waste liquid combustion furnace can be efficiently performed.
On the other hand, according to the present invention, a horizontal furnace body having an inner surface formed of bricks and having a horizontal stretching direction is suitable for increasing the size of the nitrogen-containing waste liquid combustion furnace. Particularly, in the partition structure, when the partition plate is formed, bricks can be stacked in the shape of a wall in the vertical direction, the strength can be easily secured, and this is also suitable for upsizing.

In the nitrogen-containing waste liquid combustion furnace of the present invention, the partition structure has a plurality of partition plates arranged in the stretching direction, adjacent partition plates, each of the openings, the stretching of the furnace body. It is preferable that they are formed in regions different from each other in the cross-sectional shape in the direction intersecting the direction.

In the present invention, the openings are formed in the plurality of partition plates, respectively, and the gas passing through the partition structure sequentially passes through the openings of the plurality of partition plates. That is, the concentration and diffusion of the gas by each opening are repeated every time when passing through each partition plate.
Further, the openings of the adjacent partition plates are areas different from each other, that is, areas that do not overlap with each other, and are displaced from each other in the stretching direction which is the flow direction, and are arranged at the edges. Therefore, the flow of gas passing through each partition plate is circulated to the openings at different positions for each partition plate, and as a result, the gas is subjected to the 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. As for the openings of the partition plates, it suffices that the openings are formed at the edges of at least a part of the partition plates. For example, two or more partition plates can be provided with openings that are alternately opposite sides. Further, an opening may be formed at the peripheral 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, in the plurality of partition plates, the openings of adjacent partition plates are formed on opposite sides of each other with the central portion of the cross-sectional shape sandwiched therebetween.

In the present invention, it is preferable that the openings be the most distant parts of the partition plate from each other adjacent to each other, and are formed at the opposite edges of the partition plate, or both ends in the diameter direction if the partition plate is circular. do it. For example, the openings can be above and below the divider, on the right and left of the divider, or on the upper and lower left of the divider.
When two partition plates are installed, the opening may be formed on the upper side of the upstream partition plate and the opening may be formed on the lower side of the downstream partition plate. Alternatively, the opening may be formed below the upstream partition plate and the opening may be formed above the downstream partition plate.
When installing three partition plates, an opening is formed on the upper side of the first partition plate, an opening is formed on the lower side of the second partition plate, and an opening is formed on the upper side of 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, the openings on the opposite sides are alternately formed in the plurality of partition plates, and the passing gas forms a zigzag bent flow over the entire inner diameter direction of the furnace body. Therefore, the gas flowing into the denitration chamber diffuses inside the denitration chamber and the space can be effectively used.

In the nitrogen-containing waste liquid combustion furnace of the present invention, the opening is formed in an upper portion or a lower portion of the partition plate, and the partition plate having the opening portion formed in an upper portion is an upper edge of a wall body that partitions the furnace body. It is preferable that the partition plate, which is formed horizontally and has the opening formed in the lower portion thereof, has an arched lower edge of a wall body that partitions the furnace body.

In the present invention, an arch-shaped brick stack is formed inside the furnace body, and a wall is formed by stacking bricks on it to form a partition plate having an opening below the arch-shaped lower edge. It can be easily formed.
Further, by sequentially stacking bricks horizontally from the lower surface inside the furnace body to form the wall body, it is possible to easily form the partition plate having the opening above the horizontal upper edge.

In the nitrogen-containing waste liquid combustion furnace of the present invention, 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, It is preferable that the openings of the other partition plates among the plurality of partition plates are formed on both sides of a region corresponding to the slit-shaped openings along the inner surface of the furnace body. ..

In the present invention, for example, the slit-shaped opening can be arranged so as to extend in the vertical direction. Specifically, by stacking bricks in the shape of a sleeve wall on both sides of a predetermined position inside the furnace body, a partition plate having a slit-shaped opening in the center can be formed. Further, by stacking bricks in a monolithic shape in the center of the furnace body, it is possible to form a partition plate having openings on both sides.
In the present invention, the gas that has passed through the slit-shaped opening in one partition plate branches into the openings on both sides in the next partition plate and passes through. Alternatively, the gas that has branched into and passed through the openings on both sides of one partition plate reassembles at the next partition plate and then passes through the slit-shaped openings. With such a configuration as well, the gas flowing into the denitration chamber can be diffused inside the denitration chamber, and the space in the furnace can be effectively used.

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

In the present invention, the gas flow passing through the partition structure flows into the denitration chamber through 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, the opening of the partition plate on the most downstream side of the partition structure and the opening of the auxiliary partition plate are on the opposite sides of each other, so that the gas flow crosses the inside of the denitration chamber up and down. Therefore, the space can be used more effectively.
The auxiliary partition plate may be located downstream of the blowing position of the denitration waste liquid blown upstream of the denitration chamber (downstream of the partition structure), but the gas flow after diffusion is used for denitration reaction. In order to secure a sufficient space, it is desirable to be near the outlet 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 denitration blown into the denitration chamber based on the nitrogen oxide concentration detected by the sensor And a control device that adjusts the amount of waste liquid blown in.

In the present invention, for example, the nitrogen oxide concentration of the combustion gas after the denitration process is detected at the outlet of the denitration chamber, and the amount of the denitration waste liquid blown into the denitration chamber is adjusted based on the detected nitrogen oxide concentration. Therefore, it is possible to prevent the denitration failure due to the insufficient injection amount, and to prevent the unburned denitration waste liquid from flowing out of the furnace due to the excessive injection amount.
When a part of the nitrogen-containing waste liquid is blown for denitration, it is desirable that the concentration of nitrogen oxides in the combustion gas after the denitration treatment be 45 ppm or more, and preferably 50 ppm or more. If the blowing amount of nitrogen-containing waste liquid for denitration is increased so that the concentration of nitrogen oxides becomes low, part of it will flow out of the furnace from the outlet of the denitration chamber, and ammonia or ammonium salts in the outlet gas of the denitration chamber will be discharged. The concentration of will increase. Therefore, it is desirable to prevent the nitrogen oxide concentration from becoming excessively low at the outlet of the denitration chamber. On the other hand, it is desirable that the nitrogen oxide concentration in the combustion gas after the denitration treatment be 100 ppm or less. If this value is exceeded, sufficient effectiveness as 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 NOx concentration of the combustion gas subjected to the NOx removal treatment in the NOx removal chamber is detected, and the nitrogen-containing waste liquid is blown into the NOx removal chamber based on the detected nitrogen oxides 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 concentration of nitrogen oxides in the combustion gas denitrated in the denitration chamber is 45 ppm or more and 100 ppm or less. It is preferable to adjust the blowing amount.

In the present invention, the concentration of nitrogen oxides in the combustion gas after the denitration treatment is detected, and the amount of waste liquid for denitration blown into the denitration chamber is adjusted based on the detected concentration of nitrogen oxides. It is possible to prevent the denitration failure caused by the above, and to prevent the unburned denitration waste liquid from flowing out of the furnace due to the excessive injection amount.

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

1 is a vertical sectional view showing a furnace body according to a first embodiment of the present invention. Sectional drawing which shows the partition plate which has an opening part on the upper side of the said 1st Embodiment. Sectional drawing which shows the partition plate which has an opening part under the said 1st Embodiment. The graph which shows the control standard based on the nitrogen oxide concentration of the said 1st Embodiment. FIG. 6 is a plan sectional view showing a furnace body according to a second 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 on both sides of the said 1st Embodiment.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, a nitrogen-containing waste liquid combustion furnace 1 is for incinerating a nitrogen-containing waste liquid, and has a horizontal cylindrical furnace body 10 whose stretching direction is a horizontal direction.
The furnace body 10 has an outer shell formed of a steel shell, and a brick 11 is stretched on the inner surface as a refractory material. A partition structure 20 is installed in the middle 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.

In the furnace body 10, the upstream end of the combustion chamber CB is conically narrowed, and a burner 30 for combustion is installed at the tip thereof. 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 required for combustion is blown from the air nozzle 32.
From the combustion waste liquid nozzle 33, a part of the nitrogen-containing waste liquid to be processed (10 to 40% of the nitrogen-containing waste liquid processed in the nitrogen-containing waste liquid combustion furnace 1) is blown 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 to generate a high-temperature gas in 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 in the combustion chamber CB.
From the main waste liquid nozzle 34, most of the nitrogen-containing waste liquid to be processed (60 to 90% of the nitrogen-containing waste liquid processed 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 at the same time when the ammonia contained in the waste liquid is decomposed. ..
The gas containing the incinerated waste liquid 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 on the upstream side (downstream side of the partition structure 20) of the denitration chamber CD. An exhaust stack 12 is connected to the downstream side of the denitration chamber CD.
From the denitration waste liquid nozzle 35, a part of the nitrogen-containing waste liquid to be treated containing ammonia for detoxifying the thermal NOx by denitration reaction (10 of the nitrogen-containing waste liquid treated in the nitrogen-containing waste liquid combustion furnace 1) % Or less) is blown into the inside of 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 is discharged from the exhaust pipe 12.

In the present embodiment, the partition structure 20 is configured to include a plurality of partition plates 21 and 22 according to 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.
The partition structure 20 is not limited to a structure including a plurality of partition plates, and may be a structure including one of the partition plates 21 and 22, for example.

As shown in FIG. 2, the partition plate 21 has a wall body 210 formed by stacking bricks on the bricks 11 below the furnace body 10.
The upper edge 211 of the wall body 210 is formed horizontally 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 it.

As shown in FIG. 3, the partition plate 22 is a wall body 220 formed by hanging 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 stacking the bricks on the bricks. Have.
The lower edge 221 of the wall 220 is the above-mentioned arch-shaped portion.
An opening 229 is formed between the lower edge 221 and the brick 11 facing the lower edge 221.

Therefore, the opening 219 is formed on a part of the edge of the partition plate 21 (upper side of the circumference), and the opening 229 is formed on a part of the edge of the partition plate 22 (lower side of the circumference). It As a result, the partition plates 21 and 22 are formed with the openings 219 and 229 of adjacent ones on the opposite sides (upper side and lower side).
In such a partition structure 20, the gas from the combustion chamber CB first flows through the upper opening 219 of the partition plate 21 and flows downward between the partition plates 21 and 22, and further below the partition plate 22. Through the opening 229 of the above and flows into the denitration chamber CD. As a result, the gas passing through the partition structure 20 forms a zigzag bent flow.

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 a configuration similar to that of 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 which is the opposite side 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, traverses the inside of the denitration chamber CD upward, and passes through the upper opening 239 of the auxiliary partition plate 23 to the exhaust pipe 12 Therefore, the inside of the denitration chamber CD can be effectively used.

In the present embodiment, the exhaust stack 12 is provided with a sensor 41 that detects the nitrogen oxide concentration of the passing gas. The 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 described above, and controls each regulating valve to control the fuel and the air by each. The amount of waste liquid blown in can be adjusted.

The control device 40 performs the following control.
The control device 40 detects the concentration of nitrogen oxides in the exhaust stack 12, which is the outlet of the denitration chamber CD, with the sensor 41. Then, based on the detected nitrogen oxide concentration, the injection amount 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, among them, the denitration that directly affects the denitration process. The amount of the nitrogen-containing waste liquid blown from the waste liquid nozzle 35 is adjusted.

For example, if the blowing amount of the nitrogen-containing waste liquid 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-containing waste liquid is left unburned outside the furnace from the outlet of the denitration chamber CD. As it is, the concentration of ammonia or ammonium salt in the outlet gas of the denitration chamber CD rises.
In order to prevent this, the control device 40 limits the blowing amount of the nitrogen-containing waste liquid so that the nitrogen oxide concentration does not become extremely low. As a standard for this limitation, the control device 40 adjusts the blowing amount of the nitrogen-containing waste liquid so that the nitrogen oxide concentration of the combustion gas at the outlet of the denitration 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 denitration chamber CD to be 100 ppm or less so as to obtain sufficient effectiveness as the denitration process.

FIG. 4 shows the relationship between the NH ₃ concentration related to ammonia or ammonium salt (vertical axis) and the NOx concentration related to nitrogen oxides (horizontal axis) in the outlet gas of the denitration chamber CD.
In FIG. 4, the NOx concentration is distributed in the range of 10 to 80 ppm. Of 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 the present embodiment is designed 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 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 above 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, by blowing a part of the nitrogen-containing waste liquid to be treated in the denitration chamber CD, it is possible to denitrate the gas incinerated in the combustion chamber CB.

In the above-described embodiment, the furnace body 10 of the nitrogen-containing waste liquid combustion furnace 1 is a horizontal type in which the inner surface is formed of the bricks 11 and the extending direction is the horizontal direction, which is suitable for upsizing. In particular, in the partition structure 20, when forming the partition plates 21 and 22, the bricks can be stacked in the shape of a wall in the vertical direction, the strength can be easily secured, and in this respect also, it is suitable for upsizing. is there.

In the above-described embodiment, the partition structure 20 having a plurality of partition plates 21 and 22 is used to partition the inside of the furnace body 10 into the combustion chamber CB and the denitration chamber CD. 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 zigzag bent flow. Therefore, the gas flowing into the denitration chamber CD diffuses inside the denitration chamber CD and the space can be effectively used.
Therefore, the two-stage combustion in the denitration chamber CD is efficiently performed, and the incineration process of the nitrogen-containing waste liquid as the nitrogen-containing waste liquid combustion furnace 1 can be efficiently performed.

In the above-described embodiment, the partition plate 21 having the opening 219 formed in the upper portion is the partition plate 22 having the upper edge 211 of the wall 210 for partitioning the furnace body 10 formed horizontally and the partition plate 22 having the opening 229 formed in the lower portion. The lower edge 221 of the wall 220 that partitions the furnace body 10 is formed in an arch shape.
Therefore, in the partition plate 22, an arch-shaped brick stack is formed inside the furnace body 10, and bricks are stacked thereon to form the wall body 220, so that the lower side of the arch-shaped lower edge 221 is formed. The partition plate 22 having the opening portion 229 can be easily formed.
Further, by sequentially stacking bricks horizontally from the lower surface inside the furnace body 10 to form the wall body 210, it is possible to easily form the partition plate 21 having the opening 219 above the horizontal upper edge 211. ..

In the above-described embodiment, the auxiliary partition plate 23 that partitions the inside of the furnace body 10 is installed on the downstream side of the denitration chamber CD, and the auxiliary partition plate 23 has the opening 229 (the 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.
Therefore, the gas flow passing 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 tube 12 which is the outlet of the denitration chamber CD. At this time, since 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 vertically opposite to each other, the gas flow is inside the denitration chamber CD. Since it will traverse up and down, the space can be used more effectively.
In particular, the auxiliary partition plate 23 of the present embodiment is located in the vicinity of the outlet of the denitration chamber CD, and the volume from the partition structure 20 to the auxiliary partition plate 23, that is, the space for the denitration reaction can be sufficiently secured. ..

In the above-described embodiment, the sensor 41 installed at the outlet of the denitration chamber CD for detecting the nitrogen oxide concentration in the gas after denitration and the denitration chamber CD is detected based on the nitrogen oxide concentration detected by the sensor 41. A control device 40 for adjusting the amount of the denitration waste liquid to be blown in is provided.
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 blowing amount of the 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.
Therefore, 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 the unburned denitration waste liquid due to excessive blowing amount.

[Second Embodiment]
Next, a second embodiment of the present invention will be described based on the drawings.
The present embodiment is different from the above-described first embodiment in the partition structure 20, but is common to the furnace body 10, the burner 30, and the control device 40. Therefore, description of the common configuration is omitted, and the partition structure 20A of the present embodiment will be described below.

FIG. 5 shows a horizontal sectional shape of the furnace body 10 of this embodiment.
The furnace body 10 is covered with a brick 11 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 above-described first embodiment, in the combustion chamber CB, a high temperature gas is generated by the burner 30 and a part of the nitrogen-containing waste liquid to be treated is blown to perform the incineration treatment. In addition, in the denitration chamber CD, a part of the nitrogen-containing waste liquid to be treated is blown in to denitrate the gas incinerated in the combustion chamber CB. The denitrated gas is exhausted from the exhaust stack 12.

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

As shown in FIG. 6, the partition plate 24 has a monolith-shaped wall body 240 formed by stacking bricks on the bricks 11 below the furnace body 10.
Edges 241 on both sides of the wall 240 are formed in a vertical direction, and half-moon shaped openings 249 are formed between the bricks 11 on both sides of the furnace body 10 facing each edge 241. There is.
As shown 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 sides of the lower part of the furnace body 10, and bricks are further stacked on the bricks 11 and extend upward.
Inner edges 251 of the wall body 250 are respectively formed in the vertical direction and are arranged to face each other. A slit-shaped 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 has a similar shape to the half-moon-shaped wall body 250 of the partition plate 25, and these are arranged in regions overlapping with each other.
Further, the slit-shaped wall body 240 formed on the partition plate 24 has a similar shape to the slit-shaped opening 259 formed on the partition plate 25, and these are arranged in regions overlapping with each other.
As a result, in the adjacent partition plates 24 and 25, the openings 249 and 259 are formed in regions different from each other in the cross-sectional shape in the direction intersecting the extending direction of the furnace body 10.
In such a partition structure 20A, the gas from the combustion chamber CB branches to both sides in front of the partition plate 24, passes through the openings 249, respectively, and joins again between the partition plates 24 and 25. Through the opening 259 at the center of the chamber and flows into the denitration chamber CD. As a result, the gas passing through the partition structure 20A forms a zigzag bent flow 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 a configuration similar to that of the partition plate 24 described above, and has a wall body 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 region from the opening 259 (center part) of the partition plate 25 which 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 part of the denitration chamber CD, spreads to both sides inside the denitration chamber CD, and branches again before the auxiliary partition plate 26, and the openings 269 on both sides are respectively formed. As it is, it will merge again and flow into the exhaust stack 12, and the inside of the denitration chamber CD can be effectively used.

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 shape on each side, and the gas flowing in the denitration chamber CD is discharged to the denitration chamber CD. It can be sufficiently diffused inside, and space can be effectively used.
Therefore, the partition structure 20A of the present embodiment can also obtain the same effect as that of the partition structure 20 of the first embodiment described above. With the other common configuration, the present embodiment can also obtain the same effect as the effect described in the first embodiment.

[Other Embodiments]
It should be noted that the present invention is not limited to the above-described embodiment, and modifications and the like within the range in which the object of the present invention can be achieved are included in the present invention.
In the embodiment described above, 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 bottom of the partition plate 22 are arranged so that they are alternately opposite to each other. The side opening 229 was formed.
On the other hand, the openings may be arranged upside down, such as the lower opening of the partition plate 21 and the upper opening of the partition plate 22. At this time, it is desirable that the lower edge of the lower opening is arched.
Further, it may be arranged not only in the upper and lower sides but also in the right and left directions and in another direction, for example, an opening on the upper right side toward the downstream side of the partition plate 21 and an opening on the lower left side of the partition plate 22. Can also be In this way, a zigzag flow can be formed by alternately arranging the openings of the partition plates on opposite sides.

Further, the number of partition plates installed in the partition structure 20 may be three or more, and even in this case, the openings are alternately formed on the opposite sides to form a zigzag flow. be able to.
In the present embodiment, the auxiliary partition plate 23 is provided near the outlet of the denitration chamber CD, but the position of the auxiliary partition plate 23 is the waste liquid for denitration blown to the upstream side (downstream side of the partition structure 20) of the denitration chamber CD. It suffices if it is on the downstream side of the blowing position (the blowing position of the denitration waste liquid nozzle 35). However, in order to ensure a sufficient space for the denitration reaction for the gas flow after diffusion, it is desirable to be as close as possible to the outlet of the denitration chamber CD.
It should be noted that the auxiliary partition plate 23 may also have two or more pieces, like the partition plates 21 and 22. Alternatively, if retention inside the denitration chamber CD does not matter, the auxiliary partition plate 23 may be omitted.

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

In the above-described embodiment, the sensor 41 is provided at the outlet of the denitration chamber CD, but the sensor 41 is not limited to the outlet of the denitration chamber CD as long as the concentration of nitrogen oxides in the combustion gas after denitration can be detected. You may install in the duct of the latter part of the furnace.
In the above embodiment, the control device 40 adjusts the blowing amount of the denitration waste liquid blown into the denitration chamber CD based on the nitrogen oxide concentration detected by the sensor 41. However, the adjustment is performed by the denitration waste liquid nozzle 35. Not only that, it may extend to the combustion waste liquid nozzle 33 and the main waste liquid nozzle 34.

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

INDUSTRIAL APPLICABILITY 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 part, 23... Auxiliary partition plate, 230... Wall body, 231,... Upper edge, 239... Opening part, 24... Partition plate, 240... Wall body, 241... Edges, 249... Openings, 25... Partition plates, 250... Walls, 251... Edges, 259... Openings, 26... Auxiliary partition plates, 260... Wall bodies, 261... Edges, 269... Openings, 30 ... burner, 31... fuel nozzle, 32... air nozzle, 33... combustion waste liquid nozzle, 34... main waste liquid nozzle, 35... denitration waste liquid nozzle, 40... control device, 41... sensor, CB... combustion chamber, CD... denitration Room, CP... Area of partition structure.

Claims (9)

A horizontal furnace body whose inner surface is formed of a refractory material and whose stretching direction is a lateral direction, and a partition structure for partitioning the inside of the furnace body into a combustion chamber on the upstream side and a denitration chamber on the downstream side,
The partition structure, at least a part of the edge along the inner surface of the furnace body, with an opening that communicates the upstream side and the downstream side of the partition structure ,
A sensor that detects the nitrogen oxide concentration of the combustion gas that has been denitrated in the denitration chamber,
A nitrogen-containing waste liquid combustion furnace , comprising: a controller that adjusts a blowing amount of a denitration waste liquid that is blown into the denitration chamber based on a nitrogen oxide concentration detected by the sensor . In the nitrogen-containing waste liquid combustion furnace according to claim 1,
The partition structure has a plurality of partition plates arranged in the stretching direction,
The nitrogen-containing waste liquid combustion furnace, wherein each of the adjacent partition plates has each of the openings formed in regions different from each other in a cross-sectional shape in a direction intersecting with 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, wherein the plurality of partition plates are formed such that the openings of adjacent partition plates are formed on opposite sides of each other with the central portion of the cross-sectional shape interposed therebetween. 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 portion, the upper edge of the wall body for partitioning the furnace body is formed horizontally,
The nitrogen-containing waste liquid combustion furnace, wherein the partition plate having the opening formed in the lower portion has a lower edge of a wall partitioning the furnace body formed in an arch shape. In the nitrogen-containing waste liquid combustion furnace according to claim 2,
The opening of one of the plurality of partition plates, the opening 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,
Among the plurality of partition plates, the openings of the other partition plates are formed on both sides of a region corresponding to the slit-shaped openings at the edges along the inner surface of the furnace body. Nitrogen-containing waste liquid combustion furnace. In the nitrogen-containing waste liquid combustion furnace according to any one of claims 1 to 5,
An auxiliary partition plate for partitioning the inside of the furnace body is installed on the downstream side of the denitration chamber,
The nitrogen-containing waste liquid combustion furnace, wherein the auxiliary partition plate has the opening on the opposite side of the partition plate on the most downstream side of the partition structure. The nitrogen-containing waste liquid combustion furnace according to any one of claims 1 to 6,
The nitrogen-containing waste liquid combustion furnace, wherein the sensor is installed at an outlet of the denitration chamber or a duct at a rear stage of the nitrogen-containing waste liquid combustion furnace. Using a nitrogen-containing waste liquid combustion furnace having a combustion chamber and a denitration chamber,
Combusting 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,
Detecting the nitrogen oxide concentration in the combustion gas that has been subjected to denitration treatment in the denitration chamber, and adjusting the blowing amount of the nitrogen-containing waste liquid blown into the denitration chamber based on the detected nitrogen oxide concentration. Denitration method for waste liquid combustion furnace. A denitration method for a nitrogen-containing waste liquid combustion furnace according to claim 8,
A nitrogen-containing waste liquid, wherein the blowing amount of the nitrogen-containing waste liquid blown into the denitration chamber is adjusted so that the concentration of nitrogen oxides in the combustion gas denitrated in the denitration chamber is in the range of 45 ppm or more and 100 ppm or less. Denitration method of combustion furnace.

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