Combustion nozzle and combustion type exhaust gas treatment device

Abstract

To provide a combustion nozzle in which the deposition of metal-comprising powders to a nozzle tip part can easily be suppressed, and a combustion type exhaust gas treatment apparatus.SOLUTION: A combustion nozzle 1a comprises: a first cylindrical body; a second cylindrical body; an annular wall 4 which connects the first cylindrical body and the second cylindrical body; a through hole 7 which passes through the annular wall 4 to form a combustion gas injection port; and a treatment object gas injection port which is formed inside the first cylindrical body. The through hole 7 extends in a direction in which a flow passage formed by an outside end edge 7a and an inside end edge 7b by the through hole 7 is tilted radially inward toward the tip side in an axial direction in a longitudinal plane including the central axial line O of the first cylindrical body, the outer circumferential face of the tip part of the first cylindrical body is present on an extension of the flow passage, and the thickness T of the annular wall 4 in an axial direction reduces toward the inside of a radial direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a combustion nozzle and a combustion type exhaust gas treatment device. [Background technology]

[0002] Combustion nozzles for combustion type exhaust gas treatment devices are known that treat target gases containing harmful components diluted with nitrogen gas, which are discharged from semiconductor manufacturing equipment and the like, before the gases are released into the atmosphere (see, for example, Patent Documents 1 and 2).

[0003] The combustion nozzle has a first cylindrical body, a second cylindrical body, an annular wall connecting the first cylindrical body and the second cylindrical body, a through hole penetrating the annular wall and forming a fuel gas ejection port, and an ejection port for gas to be treated formed inside the first cylindrical body. The through hole is provided such that a flow path formed by a radial outer edge and an inner edge of the through hole extends in a direction inclined radially inward toward the tip side in the axial direction in a vertical cross section including the central axis of the first cylindrical body.

[0004] The combustion type exhaust gas treatment device has a combustion nozzle, and a combustion tube that forms a combustion reaction section inside by the target gas and fuel gas injected from the radial center of the combustion nozzle. The target gas is treated by the combustion reaction section. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6734821 [Patent Document 2] Patent No. 4535558 Summary of the Invention [Problem to be solved by the invention]

[0006] When the gas to be treated contains a component that generates powder by oxidation or thermal decomposition, such as tungsten hexafluoride (WF6), depending on the components and concentrations of the gas to be treated, metal-containing powder may accumulate at the nozzle tip, affecting the performance of the combustion nozzle. However, since metal-containing powder is hard, it is difficult to automatically clean it using a mechanical powder removal device, and it usually needs to be removed by maintenance work such as disassembly and cleaning. If the accumulation of metal-containing powder at the nozzle tip can be suppressed, desirable effects such as reducing the frequency of maintenance work can be obtained.

[0007] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a combustion nozzle and a combustion type exhaust gas treatment device that can easily suppress the accumulation of metal-containing powder at the nozzle tip. [Means for solving the problem]

[0008] One aspect of the present invention is as follows.

[0009] [1] a first cylindrical body, a second cylindrical body, an annular wall connecting the first cylindrical body and the second cylindrical body, a through hole penetrating the annular wall and forming a fuel gas ejection port, and an ejection port for the gas to be treated formed on the inside of the first cylindrical body; a flow passage formed by a radial outer edge and an inner edge of the through hole in a longitudinal cross section including a central axis of the first cylindrical body extends in a direction inclined radially inward toward the axial tip side, the outer peripheral surface of the tip of the first cylindrical body is on an extension of the flow passage, and the thickness of the annular wall in the axial direction decreases toward the radially inward.

[0010] [2] The combustion nozzle according to [1], wherein, in the longitudinal section, the outer edge and the inner edge of the through hole are parallel to each other and form straight lines.

[0011] [3] The combustion nozzle according to [1] or [2], wherein, when viewed in the axial direction, the through hole has a slit shape extending linearly in the radial direction.

[0012] [4] [1] to [3], and a combustion tube forming a combustion reaction section therein by a gas to be treated and a fuel gas injected from the combustion nozzle, the combustion nozzle has a nitrogen gas jet port located radially outward of the treatment target gas jet port and radially inward of the fuel gas jet port, the combustion nozzle has a further fuel gas jet port which jets fuel gas having a higher concentration than the fuel gas jet port, the further fuel gas jet port being radially outward of the nitrogen gas jet port and radially inward of the fuel gas jet port, The combustion tube has a combustion-supporting gas injection port that injects a combustion-supporting gas toward the combustion reaction section.

[0013] [5] [1] to [3], and a combustion tube forming a combustion reaction section therein by a gas to be treated and a fuel gas injected from the combustion nozzle, the combustion nozzle has a nitrogen gas jet port located radially outward of the treatment target gas jet port and radially inward of the fuel gas jet port, The combustion tube has a premixed gas injection port that injects a premixed gas, which is a mixture of fuel gas and a combustion-supporting gas, toward the combustion reaction section. Effect of the Invention

[0014] According to the present invention, it is possible to provide a combustion nozzle and a combustion type exhaust gas treatment device that can easily suppress the accumulation of metal-containing powder at the nozzle tip. [Brief description of the drawings]

[0015] [Figure 1] 1 is a vertical cross-sectional view showing a combustion type exhaust gas treatment device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is an explanatory diagram of the operation of the combustion type exhaust gas treatment device shown in FIG. [Diagram 3]FIG. 3 is a partially enlarged view of FIG. [Figure 4] 1 is a graph showing the deposition amount of metal-containing powder measured in an example. [Diagram 5] FIG. 2 is a vertical sectional view showing a combustion type exhaust gas treatment device as Comparative Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0017] 1 to 3, in the first embodiment of the present invention, a combustion nozzle 1a has a first cylindrical body 2, a second cylindrical body 3, an annular wall 4 connecting the first cylindrical body 2 and the second cylindrical body 3, a first injection port 5 as a first fuel gas injection port, and a second injection port 6 as a treatment target gas injection port formed inside the first cylindrical body 2. The first injection port 5 is formed by a plurality of through holes 7 that are arranged in the circumferential direction and each penetrates the annular wall 4.

[0018] In addition, the direction along the central axis O of the first cylindrical body 2 is referred to as the axial direction, the direction along the axial direction toward the tip side of the first cylindrical body 2 (or the combustion nozzle 1a) is referred to as the axial tip side, and the opposite direction is referred to as the axial base side, the direction along a straight line perpendicular to the central axis O of the first cylindrical body 2 is referred to as the radial direction, the direction circumferentially around the central axis O of the first cylindrical body 2 is referred to as the circumferential direction, and a cross section including the central axis O of the first cylindrical body 2 is referred to as a longitudinal cross section.

[0019] The combustion nozzle 1a of the first embodiment has a third injection port 10 formed between the third cylindrical body 8 and the fourth cylindrical body 9, and a fourth injection port 11 formed between the fourth cylindrical body 9 and the first cylindrical body 2. The third injection port 10 injects gas flowing toward the tip end in the axial direction through a flow passage formed by the outer circumferential surface of the third cylindrical body 8 and the inner circumferential surface of the fourth cylindrical body 9 in parallel to the axial direction toward the tip end in the axial direction (see the two-dot chain line arrow in FIG. 3). The fourth injection port 11 injects gas flowing toward the tip end in the axial direction through a flow passage formed by the outer circumferential surface of the fourth cylindrical body 9 and the inner circumferential surface of the first cylindrical body 2 in parallel to the axial direction toward the tip end in the axial direction (see the two-dot chain line arrow in FIG. 3).

[0020] The third injection port 10 is formed by an annular opening formed between the tip of the third cylindrical body 8 and the tip of the fourth cylindrical body 9, which is annular when viewed in the axial direction. The fourth injection port 11 is formed by an annular opening formed between the tip of the fourth cylindrical body 9 and the tip of the first cylindrical body 2, which is annular when viewed in the axial direction. Note that the third injection port 10 and the fourth injection port 11 are not limited to the configuration formed by the annular opening as described above. Note that the annular shape is not limited to a shape that completely matches the geometric shape formed by two concentric circles of different sizes, as long as it is substantially annular.

[0021] The first cylindrical body 2, the second cylindrical body 3, the third cylindrical body 8, and the fourth cylindrical body 9 are arranged coaxially and each has a cylindrical shape. Note that the cylindrical shape is sufficient if it is substantially cylindrical, and is not limited to a shape that completely matches a geometric cylindrical shape. Furthermore, the coaxial arrangement is sufficient if it is substantially coaxially arranged, and is not limited to an arrangement in which the axial centers are completely aligned geometrically.

[0022] The second cylindrical body 3 is the radially outermost cylindrical body that constitutes the combustion nozzle 1a. The combustion nozzle 1a may be configured to have an additional cylindrical body radially outer than the second cylindrical body 3. The third cylindrical body 8 is the radially innermost cylindrical body that constitutes the combustion nozzle 1a. The combustion nozzle 1a may be configured to have an additional cylindrical body radially inner than the third cylindrical body 8.

[0023] In the first embodiment, the third jet port 10 is used as a nitrogen gas jet port, and the fourth jet port 11 is used as a second fuel gas jet port (further fuel gas jet port). That is, in the first embodiment, the nitrogen gas jet port is provided radially outward from the treatment target gas jet port and radially inward from the first fuel gas jet port, and the second fuel gas jet port is provided radially outward from the nitrogen gas jet port and radially inward from the first fuel gas jet port.

[0024] The second fuel gas ejection port ejects fuel gas having a higher concentration than the first fuel gas ejection port. For example, the fuel gas ejected from the first fuel gas ejection port may be a premixed gas obtained by mixing a 100% concentration fuel gas with a combustion supporting gas such as compressed air, compressed oxygen-enriched air, or compressed oxygen, and the fuel gas ejected from the second fuel gas ejection port may be the 100% concentration fuel gas itself. A configuration may be adopted in which premixed gas is ejected from both the first fuel gas ejection port and the second fuel gas ejection port, and the concentration of fuel gas in the premixed gas ejected from the second fuel gas ejection port may be set higher than that of the premixed gas ejected from the first fuel gas ejection port.

[0025] The fuel gas is a gas containing hydrogen atoms, such as hydrocarbons, hydrogen, ammonia, etc. However, the fuel gas is not limited to gas containing hydrogen atoms, and can be selected from various fuel gases depending on the type of gas to be treated, etc.

[0026] The gas to be treated is exhaust gas discharged from semiconductor manufacturing equipment, liquid crystal panel manufacturing equipment, solar power panel manufacturing equipment, etc., and contains components that are undesirable to be released into the atmosphere untreated, such as flammable components, toxic components, corrosive components, or components that cause global warming. The gas to be treated is supplied to the combustion nozzle 1a via a dry pump as a diluted gas diluted with nitrogen gas, and is injected from the treatment gas injection port (second injection port 6) of the combustion nozzle 1a.

[0027] The gas to be treated may be supplied to the combustion nozzle 1a as a diluted gas diluted with a gas other than nitrogen gas, or may be supplied to the combustion nozzle 1a as is without dilution. A pump other than a dry pump or a means other than a pump may be used to supply the gas to be treated to the combustion nozzle 1a.

[0028] The gas to be treated jet port (second jet port 6) jets the gas to be treated flowing toward the axial tip end of the flow passage formed by the inner circumferential surface of the third cylindrical body 8 in a direction parallel to the axial direction toward the axial tip end (see the two-dot chain arrow in FIG. 3). The second jet port 6 is formed by a circular opening that is formed by the tip end of the third cylindrical body 8 and has a circular shape when viewed in the axial direction. Note that the second jet port 6 is not limited to a configuration formed by a circular opening as described above.

[0029] The annular wall 4 connects a portion of the tip of the first cylindrical body 2 that is closer to the base end in the axial direction than the tip and the tip of the second cylindrical body 3, and forms a ring shape when viewed in the axial direction. The outer end surface 4a (the end surface on the tip side in the axial direction) of the annular wall 4 is a conical surface that is centered on the central axis O of the first cylindrical body 2 and inclined toward the tip side in the axial direction toward the outside in the radial direction. Note that the outer end surface 4a of the annular wall 4 is not limited to this, and may be configured to be a concave curved surface that is centered on the central axis O of the first cylindrical body 2 and curved toward the tip side in the axial direction toward the outside in the radial direction. The inner end surface 4b (the end surface on the base end side in the axial direction) of the annular wall 4 is a flat surface that is perpendicular to the central axis O of the first cylindrical body 2. The inner end surface 4b of the annular wall 4 is not limited to this, and may be configured, for example, to have a conical or concave curved surface shape that is centered on the central axis O of the first cylindrical body 2 and inclined or curved toward the axial tip side toward the radially outward direction, or a conical or concave curved surface shape that is centered on the central axis O of the first cylindrical body 2 and inclined or curved toward the axial base end side toward the radially outward direction.

[0030] The plurality of through holes 7 provided in the annular wall 4 are preferably arranged at equal intervals in the circumferential direction, but are not limited to this. At least one specific (preferably all) through holes 7 are preferably slit-shaped in which the through hole 7 extends linearly along the radial direction when viewed in the axial direction, but are not limited to this. Also, the specific (preferably all) through holes 7 are preferably arranged such that the radial outer edge 7a and the radial inner edge 7b of the through hole 7 are linearly parallel to each other in the longitudinal section, but are not limited to this.

[0031] The specific (preferably all) through holes 7 are provided such that, in a longitudinal section, a flow path formed by the radial outer edge 7a and the inner edge 7b of the through holes 7 extends in a direction inclined radially inward toward the axial tip, the outer peripheral surface of the tip of the first cylindrical body 2 exists on the extension of the flow path, and the thickness T of the axial annular wall 4 decreases radially inward. Note that the expression "in a longitudinal section, the outer peripheral surface of the tip of the first cylindrical body 2 exists on the extension of the flow path formed by the radial outer edge 7a and the inner edge 7b of the through holes 7" means that, in a longitudinal section, a portion of the end opening on the axial tip side of the through holes 7 projected in the direction in which the flow path extends (the direction of the two-dot chain line arrow passing through the through holes 7 in FIG. 3) overlaps with the outer peripheral surface of the tip of the first cylindrical body 2 (the overlapping portion is shown as "A" in FIG. 3).

[0032] The specific (preferably all) through holes 7 inject fuel gas in the direction of the flow path (see the two-dot chain line arrow in FIG. 3), and form a combustion flame (not shown) extending from the through holes 7 in the direction of the flow path. The outer peripheral surface of the tip of the first cylindrical body 2 exists on the extension of the flow path, so that the combustion flame can contact and efficiently heat the outer peripheral surface. In addition, since the thickness T of the axial annular wall 4 in the flow path decreases toward the inside in the radial direction, the momentum of the flow along the inner edge 7b in the radial direction in the flow path is suppressed compared to the case where the thickness T is constant, and as a result, the momentum when the combustion flame is brought into contact with the outer peripheral surface of the tip of the first cylindrical body 2 as described above can be preferably suppressed to the minimum necessary. Therefore, the adverse effect on the flow of the combustion flame and the combustion reaction section 12 caused by the combustion flame coming into contact with the tip of the first cylindrical body 2, specifically, the decrease in the stability of the combustion flame and the decrease in the heating efficiency of the combustion reaction section 12 are suppressed, and as a result, the adverse effect on the treatment efficiency of the gas to be treated can be suppressed. In order to obtain this effect, it is preferable that the radially inner edge 7b of the through hole 7 is located as radially inward as possible, and more specifically, it is preferable that the axially tip-side end of the radially inner edge 7b of the through hole 7 is located on the outer peripheral surface of the tip of the first cylindrical body 2.

[0033] The combustion type exhaust gas treatment device 1 has a combustion nozzle 1a, and a combustion cylinder 13 that forms a combustion reaction section 12 inside by the gas to be treated and fuel gas injected from the combustion nozzle 1a. The combustion reaction section 12 is formed at a joining point of the fuel gas (combustion flame) injected from the first injection port 5 (through hole 7) and the gas to be treated injected from the second injection port 6, and is located on the central axis O of the first cylindrical body 2 on the axial tip side of the nozzle tip. The combustion cylinder 13 has an outer peripheral wall section 13a that is arranged radially outward from the combustion nozzle 1a. The outer peripheral wall section 13a is cylindrical and arranged coaxially with the first cylindrical body 2.

[0034] In the first embodiment, the combustion tube 13 has a fifth injection port 14 that injects gas toward the combustion reaction section 12 (see the two-dot chain line arrow in FIG. 2). The fifth injection port 14 is formed by a plurality of openings arranged in the circumferential direction on the outer peripheral wall portion 13a of the combustion tube 13. The fifth injection port 14 may be formed by a single opening. In the first embodiment, the fifth injection port 14 is used as a combustion supporting gas injection port that injects a combustion supporting gas toward the combustion reaction section 12 in order to promote combustion of the fuel gas injected from the second fuel gas injection port.

[0035] According to the first embodiment, even if the gas to be treated contains a component such as tungsten hexafluoride (WF6) that causes metal-containing powder to be generated at the nozzle tip, the combustion flame from the first injection port 5 can be brought into contact with the outer circumferential surface of the tip of the first cylindrical body 2 to easily heat the part to a temperature equal to or higher than the sublimation temperature of the metal-containing powder, thereby making it easier to suppress deposition of the metal-containing powder on the outer circumferential surface of the tip of the first cylindrical body 2. The metal-containing powder is, for example, a metal powder or a metal oxide powder.

[0036] Furthermore, according to the first embodiment, the nitrogen gas injected from the third nozzle 10 (nitrogen gas nozzle) can move the position where the combustion reaction section 12 is formed away from the nozzle tip. In addition, by cooling the third cylindrical body 8 and the fourth cylindrical body 9, it is possible to suppress the rise in temperature of the second nozzle 6, the inside of the third nozzle 10 and the inner wall of the fourth nozzle 11 (the outer peripheral surface of the fourth cylindrical body 9) even under conditions that cause the outer peripheral surface of the tip of the first cylindrical body 2 to become hot. As a result, it is possible to suppress the accumulation of various powders formed by the components of the gas to be treated at the nozzle tip and the second nozzle 6, the third nozzle 10 and the fourth nozzle 11.

[0037] Furthermore, according to the first embodiment, the combustion reaction section 12 is heated by the fuel gas injected from the fourth injection port 11 (second fuel gas injection port) and the combustion supporting gas injected from the fifth injection port 14 (combustion supporting gas injection port), thereby improving the processing efficiency of the gas to be processed.

[0038] The combustion nozzle 1a or the combustion type exhaust gas treatment device 1 of the first embodiment may be configured not to have the fourth injection port 11 (fourth cylindrical body 9), and may be configured not to inject fuel gas from the fourth injection port 11.

[0039] The combustion type exhaust gas treatment device 1 of the first embodiment may be configured not to have the fifth injection port 14, and may be configured not to inject the combustion supporting gas from the fifth injection port 14.

[0040] Next, a second embodiment will be described with reference to Figs. 1 to 3 which are common to the first embodiment. In the second embodiment, the third injection port 10 is used as a first nitrogen gas injection port, and the fourth injection port 11 is used as a second nitrogen gas injection port. That is, in the second embodiment, two nitrogen gas injection ports are provided radially outward from the treatment target gas injection port and radially inward from the first fuel gas injection port. In the second embodiment, the fifth injection port 14 is used as a premixed gas injection port which injects a premixed gas, which is a fuel gas premixed with a combustion supporting gas, toward the combustion reaction section 12. The other configurations are the same as those of the first embodiment.

[0041] According to the second embodiment, as in the first embodiment, even if the gas to be treated contains components that cause metal-containing powder to be produced at the nozzle tip, by bringing the combustion flame from the first nozzle 5 into contact with the outer peripheral surface of the tip of the first cylindrical body 2, it is possible to easily heat that portion to above the sublimation temperature of the metal-containing powder, thereby making it easier to suppress the accumulation of metal-containing powder on the outer peripheral surface of the tip of the first cylindrical body 2.

[0042] In the first embodiment, the fuel gas injected from the fourth nozzle 11 (second fuel gas injection nozzle) and the gas to be treated injected from the second nozzle 6 (gas to be treated injection nozzle) may directly react with each other to generate metal-containing powder. In contrast, in the second embodiment, since the fuel gas is not injected from the fourth nozzle 11, such generation of metal-containing powder does not occur. Therefore, according to the second embodiment, it is easier to suppress the accumulation of metal-containing powder at the nozzle tip than in the first embodiment.

[0043] Furthermore, according to the second embodiment, the nitrogen gas injected from the third nozzle 10 (first nitrogen gas nozzle) and the fourth nozzle 11 (second nitrogen gas nozzle) can move the position where the combustion reaction section 12 is formed away from the nozzle tip. In addition, by cooling the third cylindrical body 8 and the fourth cylindrical body 9, it is possible to suppress the rise in temperature of the second nozzle 6, the inside of the third nozzle 10 and the inner wall of the fourth nozzle 11 (the outer peripheral surface of the fourth cylindrical body 9) even under conditions that cause the outer peripheral surface of the tip of the first cylindrical body 2 to become hot. As a result, it is possible to suppress the accumulation of various powders formed by the components of the gas to be treated at the nozzle tip and the second nozzle 6, the third nozzle 10 and the fourth nozzle 11.

[0044] Furthermore, according to the second embodiment, the combustion reaction section 12 is heated by the premixed gas injected from the fifth injection port 14 (premixed gas injection port), and as a result, the efficiency of treating the target gas can be improved.

[0045] The combustion nozzle 1a or the combustion type exhaust gas treatment device 1 of the second embodiment may be configured not to have the fourth injection port 11 (fourth cylindrical body 9), and may be configured not to inject nitrogen gas from the fourth injection port 11.

[0046] The combustion type exhaust gas treatment device 1 of the second embodiment may be configured not to have the fifth injection port 14, and may be configured not to inject premixed gas from the fifth injection port 14.

[0047] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit and scope of the present invention.

[0048] Therefore, the combustion nozzle 1a of the above-mentioned embodiment has a first cylindrical body 2, a second cylindrical body 3, an annular wall 4 connecting the first cylindrical body 2 and the second cylindrical body 3, a through hole 7 penetrating the annular wall 4 and forming a fuel gas injection port, and a treatment gas injection port formed inside the first cylindrical body 2, and the through hole 7 is such that in a longitudinal section including the central axis O of the first cylindrical body 2, a flow path formed by the radial outer edge 7a and the inner edge 7b of the through hole 7 extends in a direction that slopes radially inward toward the axial tip side, the outer peripheral surface of the tip of the first cylindrical body 2 is on the extension of the flow path, and the thickness T of the axial annular wall 4 decreases radially inward. This can be modified as long as it is a combustion nozzle 1a.

[0049] For example, the combustion nozzle 1a is not limited to use in the combustion type exhaust gas treatment device 1. The gas to be treated by the combustion nozzle 1a is not limited to exhaust gas from a device such as a semiconductor manufacturing device. The first cylindrical body 2, the second cylindrical body 3, the third cylindrical body 8, and the fourth cylindrical body 9 are not limited to having a cylindrical configuration, and may have a cylindrical configuration other than a cylindrical shape, such as an elliptical cylindrical configuration.

[0050] Furthermore, the combustion type exhaust gas treatment device 1 can be modified as long as it has a combustion nozzle 1a and a combustion tube 13 that forms a combustion reaction section 12 inside by the target gas to be treated and the fuel gas injected from the combustion nozzle 1a. For example, the outer peripheral wall portion 13a of the combustion tube 13 is not limited to a cylindrical configuration, and may be a tube shape other than a cylindrical shape, such as an elliptical tube shape. EXAMPLES

[0051] As Example 1, the combustion type exhaust gas treatment device of the first embodiment was used, as Example 2, the combustion type exhaust gas treatment device of the second embodiment was used, and as Comparative Example 1, as shown in FIG. 5, a device that differs only in the thickness of the annular wall and the radial position of the radial inner edge of the through hole from the combustion type exhaust gas treatment device of the first embodiment was used, and a combustion test was performed to treat a gas in which tungsten hexafluoride was diluted with nitrogen gas as the gas to be treated, and the amount of metal-containing powder deposited on the nozzle tip was confirmed. In Comparative Example 1, the axial thickness of the annular wall was constant in the radial direction. In addition, the radial position of the radial inner edge of each through hole was set so that Comparative Example 1 was radially outward compared to Example 1. In Example 1, the end of the radial inner edge of each through hole on the axial tip side was set to be located on the outer circumferential surface of the tip of the first cylindrical body.

[0052] The flow rate of tungsten hexafluoride in the gas to be treated was 1 L / min, and the flow rate of nitrogen gas in the gas to be treated was 50 L / min. The flow rates of the gas (or components of the mixed gas) injected from each gas injection port in each example were as follows. In Example 1, the first injection port was 6 L / min of fuel gas and 65 L / min of air, the third injection port was 5 L / min of nitrogen gas, the fourth injection port was 1 L / min of 100% fuel gas, and the fifth injection port was 5 L / min of air. In Example 2, the first injection port was 6 L / min of fuel gas and 65 L / min of air, the third injection port was 2.5 L / min of nitrogen gas, the fourth injection port was 2.5 L / min of nitrogen gas, and the fifth injection port was 1 L / min of 100% fuel gas and 5 L / min of air. In Comparative Example 1, the first nozzle supplied 6 L / min of fuel gas and 65 L / min of air, the third nozzle supplied 5 L / min of nitrogen gas, the fourth nozzle supplied 1 L / min of 100% fuel gas, and the fifth nozzle supplied 5 L / min of air.

[0053] The amount of metal-containing powder deposited on the nozzle tip under the above conditions is shown in Fig. 4. Fig. 4 shows the amount of metal-containing powder deposited on the combined area of ​​the outer end face of the annular wall, the outer peripheral surface of the tip of the first cylinder located axially closer to the annular wall, the tip faces of the first cylinder, the second cylinder, the third cylinder, and the fourth cylinder, and the inner peripheral surface of the tip of the third cylinder, expressed as a ratio when the amount of deposition in Comparative Example 1 is taken as 1. From the results shown in Fig. 4, a remarkable effect was confirmed in Example 1, and an extremely remarkable effect was confirmed in Example 2. [Explanation of symbols]

[0054] 1. Combustion type exhaust gas treatment equipment 1a Combustion nozzle 2 First cylinder 3 Second cylinder 4. Circular Wall 4a Outer end face 4b Inner end surface 5 1st injection port 6 2nd injection port 7 Through hole 7a Outer edge 7b Inner edge 8 Third cylinder 9 Fourth cylinder 10 Third injection port 11 4th injection port 12 Combustion reaction section 13 Combustion tube 13a Outer wall 14 No. 5 injection port O center axis T Thickness

Claims

1. a first cylindrical body, a second cylindrical body, an annular wall connecting the first cylindrical body and the second cylindrical body, a through hole penetrating the annular wall and forming a fuel gas ejection port, and a treatment target gas ejection port formed on the inside of the first cylindrical body; the through hole is a combustion nozzle in which, in a longitudinal cross section including the central axis of the first cylindrical body, a flow passage formed by a radial outer edge and an inner edge of the through hole extends in a direction inclined radially inward toward the axial tip side, the outer peripheral surface of the tip of the first cylindrical body is on an extension of the flow passage, and the thickness of the annular wall in the axial direction decreases toward the radially inward.

2. The combustion nozzle according to claim 1 , wherein in the longitudinal cross section, the outer edge and the inner edge of the through hole are parallel to each other and form straight lines.

3. The combustion nozzle according to claim 1 , wherein the through hole has a slit shape extending linearly in the radial direction when viewed in the axial direction.

4. A combustion nozzle according to any one of claims 1 to 3, and a combustion tube forming a combustion reaction section therein by the target gas and fuel gas injected from the combustion nozzle, the combustion nozzle has a nitrogen gas jet port located radially outward of the treatment gas jet port and radially inward of the fuel gas jet port, the combustion nozzle has a further fuel gas jet port which jets fuel gas having a higher concentration than the fuel gas jet port, the further fuel gas jet port being radially outward from the nitrogen gas jet port and radially inward from the fuel gas jet port, The combustion tube has a combustion-supporting gas injection port that injects a combustion-supporting gas toward the combustion reaction section.

5. A combustion nozzle according to any one of claims 1 to 3, and a combustion tube forming a combustion reaction section therein by the target gas and fuel gas injected from the combustion nozzle, the combustion nozzle has a nitrogen gas jet port located radially outward of the treatment gas jet port and radially inward of the fuel gas jet port, The combustion tube has a premixed gas injection port that injects a premixed gas, which is a mixture of fuel gas and a combustion-supporting gas, toward the combustion reaction section.

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