JP2006308275A - Exhaust gas combustion device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust gas combustion device and its method excellent in a decomposition process and making gas innoxious by continuously and surely burning toxic exhaust gas of large environmental load. <P>SOLUTION: In the exhaust gas combustion furnace in an approximately cylinder form having two or more exhaust gas introduction ducts into the furnace, a duct A is mounted in parallel with a center axis of which introduction port includes a center point of an end face of the furnace and one or more ducts B are provided so that at least part of them is mounted on an approximate cylinder surface of the furnace in a direction except for at 90° to a contact surface of the approximate cylinder surface of the furnace. In the exhaust gas combustion processing device, the introduction port of the duct B is mounted at a position closer to an end surface on which the duct A is mounted than an end surface without the duct A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to an exhaust gas treatment apparatus and a treatment method for performing a decomposition treatment by burning an exhaust gas containing a toxic gas having a high environmental load at a high temperature.

Gases emitted from industry often contain toxic and highly toxic gases, and as one of the main treatment methods of the exhaust gas, the exhaust gas is decomposed by burning it at a high temperature of 500 ° C to 1000 ° C. A method for discharging detoxified gas has been conventionally known, and there are various types of combustion treatment apparatuses used here.

For example, in the combustion treatment in the heat treatment furnace of the combustible gas generated in the waste incinerator in the waste incinerator, that is, the unburned gas in the incinerator, the unburned gas is used as high temperature air for combustion assistance. Separately, it is introduced into the heat treatment furnace in a direction along the furnace wall surface at substantially the same location, and a whirling flow is formed (for example, see Patent Document 1).

Further, in another waste combustion treatment apparatus, a swirl flow is generated in the secondary combustion chamber in the secondary combustion chamber in which the unburned components in the exhaust gas generated by the combustion in the primary combustion chamber are subjected to the combustion treatment. Further, the exhaust gas is introduced in the tangential direction of the cylindrical surface by introducing the exhaust gas into the secondary combustion chamber eccentrically outside the center line of the cross section of the secondary combustion chamber. Further, the air inlet to the secondary combustion chamber is located at a location different from the exhaust gas inlet so that the supply air to the secondary combustion chamber, which is supplementarily required in the secondary combustion chamber, is swirled. The air is introduced eccentrically outside the center line of the cross section of the next combustion chamber and the air is introduced in the tangential direction of the cylindrical surface, so that the air and the unburned components are efficiently mixed, and the unburned components are completely processed. (For example, refer to Patent Document 2).

However, the revolving flow differs in the route and number of revolving in the processing furnace depending on the flow velocity at the inlet, the inner diameter of the cylinder, the pressure difference in the processing furnace, and the like. Therefore, when these multiple fluids are introduced separately as a swirl flow, mixed and burned in the furnace and decomposed, the phases of swirl flow and the difference in the number of swirl flows are not mixed with each other. As a result, there is a possibility that the product is not sufficiently burned and decomposed.
JP 2000-199620 A Japanese Patent Application Laid-Open No. 07-229610

An object of the present invention is to provide an exhaust gas combustion treatment apparatus and a combustion treatment method for decomposing and detoxifying the exhaust gas having high environmental load and toxic exhaust gas continuously and reliably to solve the above problems. It is in.

The present invention adopts the following configuration in order to achieve the above-described problems. That is,
(1) A substantially cylindrical exhaust gas combustion treatment furnace having two or more exhaust gas introduction ducts into the furnace, the inlet of which is installed in parallel to the central axis direction including the center point of the end face of the furnace One duct A and one or more ducts B at least partially mounted on the substantially cylindrical surface in a direction other than 90 ° with respect to the contact surface of the substantially cylindrical surface of the furnace, An exhaust gas combustion treatment apparatus, wherein the introduction port is attached to a side closer to an end face with the duct A than an end face without the duct A.
(2) The duct B is mounted on the substantially cylindrical surface of the exhaust gas combustion treatment furnace or the edge between the substantially cylindrical surface and the end surface, and the mounting direction is a plane substantially perpendicular to the substantially cylindrical surface of the furnace passing through the duct B inlet. The exhaust gas combustion treatment apparatus according to (1), wherein the exhaust gas combustion treatment apparatus is inclined in the upper direction.
(3) The shape of the combustion treatment furnace for exhaust gas satisfies the following formula (1):
) Or the exhaust gas combustion treatment apparatus according to (2).

D / L ≦ 0.4
However, D: Average furnace width of the combustion treatment furnace L: Length of the combustion treatment furnace (4) In the combustion treatment furnace of the exhaust gas, a cross-sectional opening of the furnace is provided by a plate between the end surface without the duct A and the duct B The exhaust gas combustion treatment apparatus according to any one of (1) to (3), wherein at least one portion whose area is narrowed is provided.
(5) The exhaust gas according to (4), wherein the opening area in the portion where the cross-sectional opening area of the furnace is narrowed by the plate is 60% or less of the largest cross-sectional opening area of the furnace Combustion processing equipment.
(6) In a substantially cylindrical exhaust gas combustion treatment furnace, all of the exhaust gas to be treated is introduced as a central flow that flows in the direction of the central axis of the furnace, and air is introduced from one or more inlets with the inner wall of the furnace as a revolving flow. An exhaust gas combustion treatment method, which is introduced into the combustion treatment furnace.
(7) In a substantially cylindrical exhaust gas combustion treatment furnace, a part of the exhaust gas to be treated is introduced into the combustion treatment furnace as a central flow flowing in the central axis direction of the furnace, and the remaining exhaust gas to be treated is passed through the inner wall of the furnace. As a swirling flow that flows while turning, it is introduced into the combustion treatment furnace from one or more inlets. Further, as a swirling flow that flows while turning the inner wall of the furnace, it is different from one or more exhaust gas inlets. An exhaust gas combustion treatment method characterized by being introduced into the combustion treatment furnace.
(8) In a substantially cylindrical exhaust gas combustion treatment furnace, a part of the exhaust gas to be treated is introduced into the combustion treatment furnace as a central flow flowing in the central axis direction of the furnace, and the remaining exhaust gas to be treated is swirled on the inner wall of the furnace An exhaust gas combustion treatment method, wherein the exhaust gas is introduced into the combustion treatment furnace from one or more inlets as a stream.
(9) The combustion gas for auxiliary combustion is mixed with the air or the exhaust gas having a high oxygen concentration, which is introduced as a swirl flow through the inner wall of the combustion treatment furnace of the substantially cylindrical exhaust gas, before the introduction (6) to (8) The exhaust gas combustion processing method according to any one of (8).
(10) Mixing at least a part of the exhaust gas having a low oxygen concentration introduced into the combustion treatment furnace of the substantially cylindrical exhaust gas with air or an exhaust gas having a high oxygen concentration as a combustion auxiliary before introduction. The exhaust gas combustion treatment method according to any one of (6) to (9), characterized in that:
(11) The exhaust gas combustion treatment method according to any one of (6) to (10), wherein the exhaust gas introduced into the combustion treatment furnace satisfies the following formula.

Dv / Lv ≦ 0.4
However, Dv: Average diameter of the revolving flow in the combustion treatment furnace Lv: Length of the central flow passage in the combustion treatment furnace (12) The flow rate of the exhaust gas introduced into the combustion treatment furnace satisfies the following formula The exhaust gas combustion treatment method according to any one of (6) to (11), characterized in that:

Vr / Vc ≧ 7
However, Vr: Sum of revolving flow rate Vc: Center flow rate (13) The combustion heat quantity of the exhaust gas introduced into the combustion treatment furnace satisfies the following formula, and any one of the above (6) to (12) The exhaust gas combustion processing method as described.

Qbe-r / Qbe-c ≦ 0.3
However, Qbe-r: Combustion heat quantity of the self-combustion component originally contained in the swirling exhaust gas Qbe-c: Combustion heat quantity of the self-combustion component originally contained in the central flow exhaust gas (14) Gas introduced into the combustion treatment furnace The exhaust gas combustion processing method according to any one of (6) to (13), wherein the following equation is satisfied for the amount of heat:

[Qr / Vr] / [Qc / Vc] ≧ 0.1
However,

  As described below, in the combustion treatment apparatus or combustion treatment method of the present invention, the temperature spots in the combustion treatment furnace are small, and the exhaust gas efficiently contacts the high temperature portion, so that the exhaust gas is reliably burned and decomposed, It can be detoxified.

Hereinafter, the present invention will be described in more detail based on embodiments shown in the drawings.
FIG. 1a is a sketch showing an example of an exhaust gas combustion treatment apparatus according to the present invention, FIG. 1b is a side view thereof, and FIG. 1c is a cross-sectional view taken along the line AA 'shown in FIG. 1b.

  The exhaust gas to be treated is introduced from the introduction duct 2 and at least one of the introduction ducts 3-1 and 3-2, burned and decomposed in the combustion treatment furnace 1, and then discharged from the discharge duct 4.

  An example of a combustion treatment furnace (hereinafter sometimes simply referred to as a furnace) 1 in this exhaust gas treatment apparatus has three ducts for introducing exhaust gas, and has a substantially cylindrical shape. Here, the substantially cylinder includes a cylinder whose shape is a perfect circle or an ellipse in any cross section between both end surfaces 6-1 and 6-2. / A major axis ≧ 0.8 is preferable. Irregularities due to holes and doors for instruments, distortions and irregularities formed in production are considered to correspond to substantially cylinders regardless of their presence or absence. The substantially cylindrical surface is a side surface forming a substantially cylindrical curved surface. Here, the angles θ1 and θ2 formed by the substantially cylindrical end surfaces 6-1 and 6-2 and the cylindrical surface 5 are preferably 90 °, but may be 70 ° to 100 ° from the viewpoint of occupied space.

  In addition, among the exhaust gas introduction ducts, one introduction duct 2 has an introduction port 2-a including the center point of the end surface 6-1 of the furnace 1, and its mounting direction is parallel to the central axis direction of the substantially cylinder. The remaining introduction ducts 3-1 and 3-2 are attached to each other, and contact surfaces 7-1 and 7-2 of the substantially cylindrical surface 5 of the furnace 1 at the introduction ports 3-1-a and 3-2-a. It is important that the angles α1 and α2 are other than 90 ° (in FIG. 1a, the contact surface 7-1 and the angle α1 are omitted), and the angles α1 and α2 are 20 ° to 60 °. preferable. Here, the introduction ducts 3-1 and 3-2 may be attached only to the substantially cylindrical surface 5, or only a part thereof, that is, between the substantially cylindrical surface 5 and the end surface 6-1. May be. In addition, the inlets 3-1 and 3-2-a of the inlet ducts 3-1 and 3-2 are closer to the inlet 2 of the inlet duct 2 than the end surface 6-2 where the inlet 2a of the inlet duct 2 is not provided. It is attached at a distance close to the end face 6-1 having -a. One of the introduction ducts 3-1 and 3-2 may be omitted depending on the gas composition, or conversely, one or more similar introduction ducts may be provided.

  2 and 3 are side views showing another embodiment of the exhaust gas combustion treatment apparatus of the present invention. As described above, in the example of the combustion treatment apparatus shown in FIGS. 1 a to 1 c, as can be seen from FIG. 1 c, the introduction ducts 3-1 and 3-2 have their mounting directions and the introduction ports 3-1-a and 3-2. The angles γ1 and γ2 formed by the contact surfaces 7-1 and 7-2 of the substantially cylindrical surface of the furnace at −a are other than 90 °, and the angles γ1 and γ2 are preferably 20 ° to 60 °. As can be seen from FIG. 1b, the mounting direction is a plane 8 that passes through the inlets 3-1a and 3-2-a of the inlet ducts 3-1 and 3-2 and is substantially perpendicular to the substantially cylindrical surface of the furnace. -1, 8-2. Here, the substantially vertical plane is preferably such that the angles β1 and β2 of the planes 8-1 and 8-2 and the substantially cylindrical surface of the furnace are 85 ° to 95 °. With this configuration, as shown in FIGS. 2 and 3, the installation directions of the introduction ducts 3-1 and 3-2 are respectively in the introduction ports 3-1-a and 3-2 of the introduction ducts 3-1 and 3-2. The number of revolving flows in the cylindrical combustion treatment furnace 1 is larger than that in the case where it is not on the planes 8-1 and 8-2, which are substantially perpendicular to the cylindrical surface 5 of the furnace passing through a, and the flow at the furnace wall portion Therefore, the swirl flow can wrap the central flame more reliably, and the exhaust gas can be decomposed more efficiently.

Further, depending on the type of gas flowing through the introduction ducts 2, 3-1 and 3-2, it is preferable to previously mix combustion assist air before introducing the processing furnace.

  Further, regarding the furnace length L of the furnace 1 and the average furnace width D of the furnace (see FIG. 1a), it is desirable that D / L ≦ 0.4, and 0.1 ≦ D / L ≦ 0.4. More desirable. By configuring as described above, since the central flame spreads to the furnace wall, temperature spots in the machine width direction are reduced, and it is possible to efficiently decompose. Here, the average furnace width is an average value of the average diameter of the maximum portion and the average diameter of the minimum portion of the cross-sectional area of the substantially cylindrical cross section. The average diameter is the average value of the longest part and the shortest part of the cross-sectional diameter.

  The furnace length L and the average furnace width D refer to the length inside the furnace in this specification.

  Further, as shown in FIGS. 6 and 7, it is more preferable that a portion where the cross-sectional opening area of the furnace is narrowed by the plate 9 is provided between the end face without the duct A and the duct B in the furnace. Here, the cross section of a furnace means the cross section of the furnace by the surface orthogonal to the longitudinal direction of a substantially cylindrical furnace. By making the opening partly narrower than the largest cross-sectional opening of the furnace, the gas is mixed more in the furnace, the temperature spots in the machine width direction are reduced, and the exhaust gas can be decomposed more efficiently Because it becomes. 6 and 7, two such portions are provided. The number of installation locations is preferably as many as possible, but if the number is too large, the effect may not be increased so much, and more energy is consumed by exhaust gas supply due to increased pressure loss. Is more preferable.

  The position of the opening in the area where the cross-sectional opening area is narrow is not particularly limited, and may be a position formed by installing a plate having a partial shape on one side of the cross-sectional shape of the furnace as shown in FIGS. Alternatively, it may be a position formed by installing a punching-like plate or a donut-like plate with a hollowed center. However, when installing a plurality of places where the cross-sectional opening area is narrowed, the positions of the two adjacent openings do not overlap, for example, as shown in FIGS. This is preferable because the gas mixing effect is further increased.

  Further, the opening area in the portion where the sectional opening area is narrowed is 60% or less, preferably 20% or more and 60% or less of the sectional area of the largest sectional opening in the furnace. This is because if it exceeds 60%, the mixing effect of the gas will be reduced, and if it is less than 20%, a large amount of energy will be consumed by exhaust gas supply due to an increase in pressure loss.

  Next, an exhaust gas combustion processing method using the exhaust gas combustion processing apparatus of the present invention will be described.

  As an embodiment of the exhaust gas combustion treatment method of the present invention, all exhaust gas to be burnt is introduced into the combustion treatment furnace 1 as a central flow flowing in the direction of the center axis of the furnace from the introduction duct 2 to form a central flame in the furnace. On the other hand, there is a method of forming a swirl flow by introducing air from the introduction duct 3-1. By the above method, the swirl flow wraps the central flame, so the temperature drop near the wall of the central flow is suppressed and the outflow of the central flame to the furnace wall can be prevented. Becomes higher.

However, when the amount of the treated exhaust gas is excessive with respect to the size of the combustion treatment furnace 1, if it is introduced as a central flow from the introduction duct 2, all the air as a revolving flow must be introduced. The total gas flow to be made becomes enormous, the residence time is lowered, and the combustion efficiency is lowered. In such a case, when there are a plurality of types of exhaust gas and there is a large difference in the amount of combustion heat of each exhaust gas, the exhaust gas having a high amount of combustion heat is introduced as a central flow from the introduction duct 2 and other exhaust gases are introduced into the air It is good to introduce | transduce as a rotational flow from the introduction duct 3-2 different from the introduction duct 3-1. By this method, the flow rate of air from the introduction duct 3-1 can be reduced, and the residence time can be increased, so that the combustion efficiency is improved. At this time, the air and the exhaust gas may be mixed in advance and then introduced from the introduction duct 3-1, but the area of the introduction port 3-1-a is reduced in order to suppress an increase in pressure loss in the introduction duct 3-1. Since it must be enlarged and the shape of the swirl flow is likely to be disturbed, it is more preferable to introduce it from a separate inlet.

  Further, at this time, if the amount of the exhaust gas having the lower combustion heat amount is sufficient, the air itself may not be introduced, and the entire revolving flow may be formed by introducing the exhaust gas, and the exhaust gas decomposition treatment may be performed. The amount of air used can be completely reduced, and the residence time can be increased, so that the combustion efficiency is further improved.

  On the other hand, when the temperature cannot be increased to the combustion temperature necessary for gas decomposition only by the amount of combustion heat of the components in the exhaust gas, the combustion heat amount is mixed with air before introduction to increase the combustion heat amount, then burner flame Then, it is introduced into the combustion treatment furnace 1 as a swirling flow that flows while swirling the inner wall of the furnace. Of course, the temperature can be raised to the combustion temperature necessary for the decomposition treatment of the exhaust gas by this method, and the temperature of the swirl flow itself is also increased, so that temperature spots in the machine width direction are reduced and the combustion efficiency of the exhaust gas is further increased. At this time, the role of air is to supply oxygen to promote combustion of the combustion gas for auxiliary combustion, and the flow rate ratio of air and combustion gas for auxiliary combustion has a ratio that is more suitable than the type of combustion gas for auxiliary combustion. It is desirable to mix so that it may become the ratio. At this time, if there is an exhaust gas having a high oxygen concentration in one or a plurality of types of exhaust gas to be introduced into the combustion treatment furnace 1, the exhaust gas is used as a substitute for air and the combustion combustion gas is mixed. You may introduce | transduce into the combustion processing furnace 1 as a revolving flow.

  In addition, when there is an exhaust gas having a low oxygen concentration in one or a plurality of types of exhaust gas to be introduced into the combustion treatment furnace 1, combustion auxiliary air is mixed before introduction into the combustion treatment furnace 1. Is good. By this method, the exhaust gas in the furnace is burned more efficiently. At this time, when there is an exhaust gas having a high oxygen concentration in one or a plurality of types of exhaust gas introduced into the combustion treatment furnace 1, the exhaust gas may be used as a substitute for combustion auxiliary air. This method can reduce the amount of air introduced into the combustion treatment furnace 1, thereby increasing the residence time and improving the combustion efficiency.

The low oxygen concentration mentioned above means that the oxygen concentration is less than 5 vol%, and the high oxygen concentration means that the oxygen concentration is 5 vol% or more.
Moreover, it is desirable that the following conditions are satisfied for the flow of exhaust gas introduced into the combustion treatment furnace 1.

Dv / Lv ≦ 0.4
More preferably,
0.1 ≦ Dv / Lv ≦ 0.4
It is.
However, Dv: Average diameter of the swirl flow in the combustion treatment furnace 1 Lv: Length of the central flow passage portion in the combustion treatment furnace 1 Here, the mean diameter Dv of the swirl flow is the average furnace width D of the combustion treatment furnace 1 The length Lv of the central flow combustion treatment furnace passage portion is defined as the same length as the furnace length L of the combustion treatment furnace. By satisfying the above conditions, since the central flame reaches the furnace wall, temperature spots in the machine width direction are reduced, and the exhaust gas can be efficiently decomposed.

  Moreover, it is desirable that the following conditions are satisfied for the flow rate of the exhaust gas introduced into the combustion treatment furnace 1.

Vr / Vc ≧ 7
More preferably,
7 ≦ Vr / Vc ≦ 20
It is.
However, Vr: Turning flow rate (total)
Vc: Center flow rate By satisfying the above conditions, the swirling flow can sufficiently wrap the center flame, so that the furnace wall can be kept warm, temperature fluctuations in the machine width direction can be reduced, and the exhaust gas can be decomposed. It becomes. If Vr / Vc is less than 7, the temperature variation of the machine width method increases, leading to a reduction in decomposition efficiency. If it exceeds 20, the central flame becomes relatively small and the shape stability of the flame is lowered, so that the combustion becomes impossible.

  Moreover, it is desirable that the following conditions are satisfied for the amount of combustion heat of the exhaust gas introduced into the combustion treatment furnace 1.

Qbe-r / Qbe-c ≦ 0.3
More preferably,
0.05 ≦ Qbe-r / Qbe-c ≦ 0.3
It is.
However, Qbe-r: Combustion calorie of the self-combustion component originally contained in the swirling exhaust gas Qbe-c: Combustion calorie of the self-combustion component originally contained in the central flow exhaust gas By satisfying the above conditions, Many are contained in the central flow, and the central flame is more stably formed, so that the exhaust gas can be decomposed efficiently.

  Moreover, it is desirable that the following conditions are satisfied for the amount of heat of the gas introduced into the combustion treatment furnace 1.

[Qr / Vr] / [Qc / Vc] ≧ 0.1
More preferably,
0.1 ≦ [Qr / Vr] / [Qc / Vc] ≦ 20
It is.
However,

  If the above conditions are met, the temperature rise due to the exothermic reaction of the swirl flow is higher than the temperature rise due to the exothermic reaction of the central flow, so that the temperature difference between the two becomes small and the exhaust gas can be decomposed efficiently. Become. On the other hand, if [Qr / Vr] / [Qc / Vc] is less than 0.1, the temperature rise due to the exothermic reaction in the central flow is significantly smaller than the temperature rise due to the exothermic reaction in the central flow. The temperature spots increase and lead to a reduction in decomposition efficiency. If the temperature exceeds 20, the temperature of the furnace wall becomes very high, so that there is a possibility of damage such as cracking of the inner wall by heat.

In addition, the total flow rate of the treated exhaust gas and air or the like to be introduced into the combustion treatment furnace 1 is 1000 to 40000 Nm ³ in consideration of the effect on the combustion decomposition efficiency due to the exhaust gas mixing property in the furnace and the temperature unevenness in the furnace. / H is desirable.

Example 1
As an acrylic fiber, an acrylonitrile polymer was spun, drawn, and washed with water, and then an oil agent was adhered to obtain a fiber yarn. In order to make this yarn group into carbon fiber by continuous production, the total passing amount of this yarn group at the entrance to the high-temperature treatment furnace (1) is set to 200 kg / h in the high-temperature heat treatment furnace (1). After heat treatment for 80 minutes in an air atmosphere at 200 ° C. to 300 ° C., heat treatment was performed in a high temperature heat treatment furnace (2) for 10 minutes in a nitrogen atmosphere at 500 ° C. to 1800 ° C. to obtain carbon fibers. At this time, the supply flow rate and exhaust gas flow rate of fresh air in the high-temperature treatment furnace (1) were both 3500 Nm ³ / h, and the exhaust gas temperature was 200 ° C. In addition, the supply flow rate and exhaust gas flow rate of fresh nitrogen in the high-temperature treatment furnace (2) were both 300 Nm ³ / h, and the exhaust gas temperature was 400 ° C. These exhaust gases contain HCN that is toxic and has a high environmental load (it is necessary to decompose HCN before releasing the exhaust gases). In this example, the HCN in the exhaust gas of the high-temperature heat treatment furnace (1) is used. The concentration was 0.1 vol%, and the concentration of HCN in the exhaust gas from the high temperature treatment furnace (2) was 2 vol%. At this time, heat of combustion of the self-retardant component of the exhaust gas, high temperature processing furnace (1) in the exhaust gas from 11kcal / Nm ^3, was a 1250kcal / Nm ³ in the exhaust gas from the high temperature processing furnace (2). These exhaust gases were subjected to combustion decomposition treatment in a combustion treatment apparatus of the type shown in FIGS. 1a to 1c in which the furnace length L is 3 m and the furnace width D is 1.1 m. From the introduction duct 2, the exhaust gas 300Nm ³ / h from the high temperature heat treatment furnace (2) previously mixed with 150 Nm ³ / h air was introduced at 400 ° C. through the introduction port 2-a. Further, a gas in which 500 Nm ³ / h of exhaust gas from kerosene 50 l / h and high-temperature heat treatment furnace (1) is mixed is introduced from the introduction duct 3-1 at 200 ° C. through the introduction port 3-1-a. I ignited in the mouth. The combustion heat quantity of kerosene was 8000 kcal / l. Further, from the introduction duct 3-2, the remaining exhaust gas 3000Nm ³ / h from the high temperature treatment furnace (1) was introduced at 200 ° C. through the introduction port 3-2-a. As a result of carrying out the combustion decomposition treatment as described above, the combustion temperature in the furnace was 800 ° C., and the HCN concentration of the exhaust gas after treatment was 5 volppm, which was sufficient for the decomposition treatment. In addition, the specific heat of the air and exhaust gas in the above-mentioned examples and later-described examples and comparative examples were all 0.35 kcal / Nm ³ · ° C.

Example 2
In Example 1, three yarn groups were fired separately in a high temperature heat treatment furnace (1) and a high temperature heat treatment furnace (2) to obtain carbon fibers. At this time, the total passing amount of the yarn group in the high temperature heat treatment furnace (1) on the entry side is 700 kg / h in each group, and the fresh air supply flow rate in each high temperature treatment furnace (1), the flow rate of the flue gas together 11500Nm ³ / h, the air supply flow rate of fresh nitrogen at each set of high-temperature processing furnace (2), exhaust gas flow rate are both set to 1000 Nm ³ / h, the condition of rest of the furnace was the same as in example 1 . At this time, the concentration of HCN in the exhaust gas from each set of high-temperature heat treatment furnaces (1) was 0.1 vol%, and the concentration of HCN in the exhaust gas from each set of high-temperature heat treatment furnaces (2) was 2 vol%. The heat of combustion of the self-retardant component of the exhaust gas at this time, each set 10 kcal / Nm ³ in the exhaust gas from the high-temperature heat treatment furnace (1), became each set 1310kcal / Nm ³ in the exhaust gas from the high-temperature heat treatment furnace (2) . The exhaust gases from these respective sets were mixed in a high-temperature heat treatment furnace by each, the total amount of exhaust gas 3000 Nm ³ / h of the total quantity of exhaust gas 34500Nm ³ / h and the high-temperature heat treatment furnace from the high temperature processing furnace (1) (2), the furnace Combustion decomposition treatment was performed in a combustion treatment apparatus of the type shown in FIG. 1 having a length L of 6.2 m and a furnace width D of 2 m. From the introduction duct 2, exhaust gas 3000 Nm ³ / h from the high-temperature heat treatment furnace (2) previously mixed with 1500 Nm ³ / h air was introduced at 400 ° C. through the introduction port 2-a. Further, from the introduction duct 3-1, a gas mixed with 5000 Nm ³ / h of the kerosene 500 l / h and the exhaust gas from the high-temperature heat treatment furnace (1) is introduced at 200 ° C. through the introduction port 3-1-a, I ignited with. The combustion heat quantity of kerosene was 8000 kcal / l. Further, from the introduction duct 3-2, the remaining exhaust gas 29500 Nm ³ / h from the high temperature treatment furnace (1) was introduced at 200 ° C. through the introduction port 3-2-a. As a result of carrying out the combustion decomposition treatment as described above, the combustion temperature in the furnace was 800 ° C., and the HCN concentration of the exhaust gas after treatment was 5 volppm, and the decomposition treatment could be sufficiently performed.

Example 3
A combustion treatment apparatus of the type shown in FIG. 2 was used to introduce a gas into the combustion treatment furnace 1 under the same conditions as in Example 1 to perform the combustion decomposition treatment. The combustion temperature in the furnace at this time was also 800 ° C., and the HCN concentration of the exhaust gas after treatment was 15 volppm, which could be decomposed.

Example 4
To change the ratio of the rotational flow and the central stream in Example 1, were mixed with the exhaust gas 300 Nm ³ / h of 500 Nm ³ / h of exhaust gas from the high-temperature heat treatment furnace (1) from the high temperature processing furnace (2). Since the exhaust gas from the high-temperature heat treatment furnace (1) contains sufficient air, it is not mixed with the air as in the first embodiment, and this exhaust gas is supplied from the introduction duct 2 through the introduction port 2-a at 350. It was introduced into the combustion treatment furnace 1 at 0 ° C. Further, from the introduction duct 3-1, kerosene 45 l / h and 450 Nm ³ / h of the exhaust gas from the high-temperature heat treatment furnace (1) were mixed and introduced at 200 ° C. through the introduction port 3-1-a and ignited. . Further, from the introduction duct 3-2, the remaining exhaust gas 2550Nm ³ / h from the high-temperature treatment furnace (1) is introduced at 200 ° C. through the introduction port 3-2-a, and other conditions are the same as in the first embodiment. Combustion decomposition treatment was performed. At this time, the combustion temperature in the furnace was 800 ° C., the concentration of HCN after the treatment was 20 vol ppm, and the decomposition treatment capacity was slightly reduced.

Example 5
In Example 1, a combustion treatment apparatus of the type shown in FIGS. 1a to 1c in which the furnace length L is 2.5 m and the furnace width D is 1.5 m was used, and the combustion decomposition treatment was performed in the same manner under other conditions. . At this time, the combustion temperature in the furnace was 800 ° C., and the concentration of HCN after the treatment was 20 vol ppm, and the decomposition treatment capacity was slightly reduced.

Example 6
Mixed in Example 1, from the inlet duct 2, a 225 nm ³ / h and air 150 Nm ³ / h of exhaust gas from 75 nM ³ / h and the high-temperature processing furnace of the exhaust gas from the high-temperature heat treatment furnace (1) (2) The introduced gas was introduced at 400 ° C. through the inlet 2-a. In addition, a gas obtained by mixing 500 Nm ³ / h of the exhaust gas from kerosene 50 l / h and the high-temperature heat treatment furnace (1) is introduced from the introduction duct 3-1 at 200 ° C. through the introduction port 3-1-a and ignited. I let you. The remaining exhaust gas 2925Nm ³ / h and the remaining exhaust gas 75 nM ³ / h were mixed gases from the high temperature processing furnace (2) from the high-temperature heat treatment furnace from the inlet duct 3-2 (1), inlet 3-2 -A was introduced at 200 ° C., and the combustion decomposition treatment was performed in the same manner as in Example 1 except for the other conditions. At this time, the combustion temperature in the furnace was 800 ° C., and the concentration of HCN after the treatment was 20 vol ppm, and the decomposition treatment capacity was slightly reduced.

Example 7
As shown in FIG. 6, the combustion decomposition treatment was performed by introducing gas into the combustion treatment furnace 1 under the same apparatus and conditions as in Example 1 except that the cross-sectional opening area was narrowed at two locations by installing the plate 9. . In addition, the cross-sectional opening area of the part in which the plate 9 was installed was 70% of the cross-sectional opening area in the part where the plate 9 was not installed. The furnace combustion temperature at this time was 800 ° C., and the HCN concentration of the exhaust gas after treatment was 4 vol ppm, which was a further sufficient decomposition treatment than in Example 1.

Example 8
As shown in FIG. 7, gas was introduced into the combustion treatment furnace 1 under the same apparatus and conditions as in Example 1 except that the cross-sectional opening area was narrowed at two locations by installing the plate 9, and the combustion decomposition treatment was performed. . In addition, the cross-sectional opening area of the part in which the plate 9 was installed was 40% of the cross-sectional opening area in the part where the plate 9 was not installed. The in-furnace combustion temperature at this time was 800 ° C., and the HCN concentration of the exhaust gas after treatment was 2 vol ppm, so that the decomposition treatment could be performed more sufficiently than in Example 7.

Comparative Example 1
In the combustion treatment apparatus shown in FIGS. 1a to 1c, for the exhaust gas discharged in the same manner as in Example 1 using the combustion treatment apparatus of the type without the introduction duct 2 shown in FIG. Of the exhaust gas from the high temperature treatment furnace (1), a gas in which 500 Nm ³ / h and kerosene 501 / h are mixed is introduced into the combustion treatment furnace 1 at 200 ° C. at the inlet 3-1-a and ignited. It was. Further, from the introduction duct 3-2, a gas obtained by mixing the remaining exhaust gas 3000Nm ³ / h from the high temperature treatment furnace (1) and 300 Nm ³ / h discharged from the high temperature treatment furnace (2) is introduced into the introduction port 3-2. -A was introduced into the combustion treatment furnace 1 at 200 ° C. As a result of the combustion decomposition treatment as described above, the combustion temperature in the furnace became 800 ° C. However, since only a revolving flow was generated, the concentration of HCN after treatment was 200 volppm, and the decomposition treatment capacity was insufficient. It was.

Comparative Example 2
In the combustion treatment apparatus shown in FIG. 1, exhaust gas discharged from the introduction duct 2 is exhausted in the same manner as in the first embodiment using the combustion treatment apparatus of the type without the introduction ducts 3-1 and 3-2 shown in FIG. 5. The exhaust gas 3500 Nm ³ / h from the high-temperature treatment furnace (1), 50 l of kerosene and the exhaust gas 300 Nm ³ / h from the high-temperature treatment furnace (2) are mixed in advance, and then the combustion treatment furnace at 200 ° C. at the inlet 2-a 1 was ignited and subjected to combustion decomposition treatment. At this time, the combustion temperature in the furnace was 800 ° C., but since only the central flow was generated, the HCN concentration after the treatment was 500 volppm, and the decomposition treatment capacity was insufficient.

It is a sketch which shows an example of the exhaust gas combustion processing apparatus of this invention. 1b is a side view of FIG. It is A-A 'arrow line view of FIG. 1b. It is a side view which shows the other Example of the exhaust gas combustion processing apparatus of this invention. It is a side view which shows the further another Example of the exhaust gas combustion processing apparatus of this invention. It is a sketch which shows an example of the conventional exhaust gas combustion processing apparatus. It is a sketch which shows another example of the conventional exhaust gas combustion processing apparatus. It is a see-through | perspective side view which shows the further another Example of the exhaust gas combustion processing apparatus of this invention. It is a see-through | perspective side view which shows the further another Example of the exhaust gas combustion processing apparatus of this invention.

Explanation of symbols

1: Combustion treatment furnace 2: Introduction duct 2-a: Introduction port of introduction duct 2 3-1: Introduction duct 3-1-a: Introduction port of introduction duct 3-1 3-2: Introduction duct 3-2-a : Introduction port of introduction duct 3-2: discharge duct 5: substantially cylindrical surface 6-1: end surface of combustion treatment furnace 6-2: end surface of combustion treatment furnace 7-1: introduction port 3 of introduction duct 3-1 1-a, the contact surface (virtual surface) of the substantially cylindrical surface 5 of the furnace
7-2: Contact surface (virtual surface) of the substantially cylindrical surface 5 of the furnace at the introduction port 3-2-a of the introduction duct 3-2
8-1: A plane (virtual plane) passing through the inlet 3-1-a of the introduction duct 3-1 and perpendicular to the substantially cylindrical surface 5 of the furnace
8-2: A plane (virtual plane) passing through the introduction port 3-2-a of the introduction duct 3-2 and perpendicular to the substantially cylindrical surface 5 of the furnace
9: Board

Claims (14)

A combustion treatment furnace for a substantially cylindrical exhaust gas having two or more exhaust gas introduction ducts into the furnace,
One duct A, the inlet of which includes the center point of the end face of the furnace, which is mounted in parallel in the direction of the central axis, and at least a part thereof in a direction other than 90 ° with respect to the contact surface of the substantially cylindrical surface of the furnace Has one or more ducts B mounted on a substantially cylindrical surface, and the inlet of the duct B is mounted closer to the end surface with the duct A than the end surface without the duct A. Exhaust gas combustion treatment equipment. Duct B is mounted on the substantially cylindrical surface of the exhaust gas combustion treatment furnace or on the edge between the substantially cylindrical surface and the end surface, and the mounting direction is on a plane substantially perpendicular to the substantially cylindrical surface of the furnace passing through the inlet of duct B. 2. The exhaust gas combustion treatment apparatus according to claim 1, wherein the exhaust gas combustion treatment apparatus is inclined. The exhaust gas combustion treatment apparatus according to claim 1, wherein the following formula is satisfied with respect to a shape of the exhaust gas combustion treatment furnace.
D / L ≦ 0.4
Where D: average furnace width of the combustion treatment furnace L: furnace length of the combustion treatment furnace   In the exhaust gas combustion treatment furnace, at least one portion in which the cross-sectional opening area of the furnace is narrowed by a plate is provided between the end surface without the duct A and the duct B. Item 4. The exhaust gas combustion treatment apparatus according to any one of Items 1 to 3.   The exhaust gas combustion treatment apparatus according to claim 4, wherein an opening area in a portion where the cross-sectional opening area of the furnace is narrowed by the plate is 60% or less of a largest cross-sectional opening area of the furnace. In a substantially cylindrical exhaust gas combustion treatment furnace, all of the exhaust gas to be treated is introduced as a central flow that flows in the direction of the central axis of the furnace, and air is combusted from one or more inlets with the inner wall of the furnace as a revolving flow. An exhaust gas combustion treatment method characterized by being introduced into a furnace. In a combustion treatment furnace for a substantially cylindrical exhaust gas, a part of the exhaust gas to be treated is introduced into the combustion treatment furnace as a central flow flowing in the central axis direction of the furnace, and the remaining exhaust gas to be treated is rotated on the inner wall of the furnace Introduce into the combustion treatment furnace from one or more inlets as a flowing swirl, and further introduce air into the combustion treatment furnace from one or more inlets separate from the exhaust gas inlet through the inner wall of the furnace. An exhaust gas combustion treatment method comprising: In a combustion treatment furnace for a substantially cylindrical exhaust gas, a part of the exhaust gas to be treated is introduced into the combustion treatment furnace as a central flow that flows in the central axis direction of the furnace, and the remaining exhaust gas to be treated is a swirl flow on the inner wall of the furnace. An exhaust gas combustion treatment method comprising introducing into the combustion treatment furnace from more than one inlet. 9. An auxiliary combustion combustion gas is mixed with air or high oxygen concentration exhaust gas introduced as a swirl flow through the inner wall of a combustion treatment furnace of substantially cylindrical exhaust gas before introduction. 2. An exhaust gas combustion processing method described in 1. It is characterized in that air or high oxygen concentration exhaust gas is mixed with at least a part of the exhaust gas having a low oxygen concentration introduced into the combustion treatment furnace of the substantially cylindrical exhaust gas before the introduction as a combustion auxiliary. The exhaust gas combustion processing method according to any one of claims 6 to 9. The exhaust gas introduced into the combustion treatment furnace satisfies the following formula:
The exhaust gas combustion treatment method according to any one of 10 to 10.
Dv / Lv ≦ 0.4
However, Dv: Average diameter of the swirling flow in the combustion treatment furnace
Lv: Length of the central flow passage in the combustion treatment furnace The exhaust gas combustion treatment method according to any one of claims 6 to 11, wherein the following expression is satisfied with respect to a flow rate of the exhaust gas introduced into the combustion treatment furnace.
Vr / Vc ≧ 7
However, Vr: Sum of turning flow rate
Vc: Center flow rate The exhaust gas combustion treatment method according to any one of claims 6 to 12, wherein the following equation is satisfied with respect to the amount of combustion heat of the exhaust gas introduced into the combustion treatment furnace.
Qbe-r / Qbe-c ≦ 0.3
However, Qbe-r: Combustion heat quantity of the self-combustion component originally contained in the swirling flow exhaust gas Qbe-c: Combustion heat amount of the self-combustion component originally contained in the central flow exhaust gas The exhaust gas combustion processing method according to any one of claims 6 to 13, wherein the following equation is satisfied with respect to the amount of heat of the gas introduced into the combustion processing furnace.
[Qr / Vr] / [Qc / Vc] ≧ 0.1
However,

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