JP3828083B2 - Exhaust gas treatment equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exhaust gas treating apparatus of Ru by combusting combustible gas contained in exhaust gas discharged from a semiconductor manufacturing device or the like, is suitably used especially when the combustible gas is hydrogen (H ₂₎ .
[0002]
[Prior art]
Since exhaust gas discharged from a manufacturing apparatus such as a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus often contains a dangerous combustible gas, it cannot be released into the atmosphere as it is. In view of this, combustible gas is burned by a heat source before being released into the atmosphere using an exhaust gas treatment device. Conventionally, according to the type of the heat source, the exhaust gas treatment apparatus has an ignition / combustion system (for example, see Patent Document 1) using a single heat source and an ignition / combustion system for an electric spark (for example, see Patent Document 2). is there.
[0003]
FIG. 2 shows an ignition and combustion system using a single heat source. The configuration of the combustion processing apparatus using a single heat source is as follows. A single heat source 13 is provided in the combustion chamber 14 provided with the combustible gas introduction pipe 8, the exhaust pipe 11, and the air intake port 12. The single heat source 13 is a case 15 made of metal that transmits heat to the entire circumference, an electric heater 16 that is arranged in the case 15 and converts electric energy into heat energy, and the temperature of the heat source 13. It comprises a thermocouple 5 to be detected and an insulating material 17 that fills the space in the case 15. Electric power to the electric heater 16 is controlled by the temperature controller 7 provided outside the combustion chamber 14 so that the temperature of the heat source 13 detected by the thermocouple 5 is maintained at a predetermined temperature.
[0004]
Air (air) is taken into the combustion chamber 14 from the air intake port 12 by suction from the exhaust pipe 11, and air is constantly flowing into the combustion chamber 14. A hydrogen (H ₂ ) gas having a controlled flow rate is supplied from the ignition gas pipe 24 and reacted with oxygen in the atmosphere by the thermal energy of the single heat source 13 to ignite hydrogen. After ignition, the exhaust gas flows from the combustible gas introduction pipe 8 into the combustion chamber 14 and is mixed with oxygen in the atmosphere, and the combustible gas contained in the exhaust gas is combusted by the ignition and the heat energy of the heat source. The combustion process is performed. The burned gas is discharged from the exhaust pipe 11.
[0005]
In such a single heat source method, when the mixing ratio of the combustible gas is high among the combustible gas and the non-combustible gas constituting the exhaust gas, the residual concentration of the combustible gas is sufficiently combusted. Shows a low value, but when the mixing ratio is low, it is almost unburned, so the residual concentration shows a high value, and the unburned gas is discharged from the exhaust pipe 11 as it is. Moreover, since it is a single heat source, when the electric heater 16 is disconnected, the heat supply to the heat source 13 is stopped, and ignition and combustion cannot be performed. Further, the peripheral wall of the heat source 13 due to high-temperature combustion and the electric heater 16 in the case 15 are easily disconnected due to reaction heat due to high-temperature combustion, and the operating temperature range is limited.
[0006]
FIG. 3 shows the ignition and combustion method of the electric spark. The basic configuration is the same as the ignition and combustion method using a single heat source shown in FIG. The difference is that ignition / combustion is performed not by an electric heater but by an electric spark. The configuration of the electric spark is such that the burner electrodes 28 and 28 are connected to a step-up transformer 29 for increasing the voltage, and a spark is generated by a high voltage.
[0007]
Hydrogen (H ₂ ) gas is caused to flow from the ignition gas pipe 24 into the combustion chamber 14 in which air is constantly flowing, and hydrogen is ignited by reacting with oxygen in the atmosphere by the electric spark energy. After ignition, the exhaust gas flows from the combustible gas introduction pipe 8 into the combustion chamber 14 and is mixed with oxygen in the atmosphere. The combustible gas contained in the exhaust gas is combusted by the flame 10 by ignition, and the exhaust gas is burned. Do.
[0008]
However, when the ignition cannot be ignited, the electric spark repeatedly sparks, and if the flammable gas concentration reaches an abnormally high concentration when ignited, a problem may occur. Further, the burner electrode 28 may not be ignited due to deterioration of the burner electrode 28 and may not ignite. Further, the flame 10 generated by the combustion fluctuates due to the pressure of the exhaust pipe 11, and the combustion efficiency becomes unstable. Further, in this case as well, as in the method using a single heat source, the combustion region is one of the outlets of the combustible gas introduction pipe, and when oxygen in the air is excessive, a low concentration combustible gas is used. There is a problem that the combustion treatment efficiency is poor.
[0009]
The single heat source method and the electric spark method require an ignition gas facility as shown in FIGS. 2 and 3 in order to perform safe combustion. Usually, hydrogen (H ₂ ) is used as the ignition gas. In the configuration of the ignition gas equipment, an ignition gas pipe 24 is connected to the combustion chamber 14, and hydrogen (H ₂ ) gas passing through the ignition gas pipe 24 is supplied to the combustion chamber 14. For this purpose, impurities contained in hydrogen (H ₂ ) gas flowing through the pipe 24 via the manual valve 18 are removed by a filter 19 and the pressure of the pressure gauge 21 is visually monitored to manually adjust the hydrogen (H ₂ ) gas pressure. It is necessary to control by the regulator 20 and to control the flow rate by the mass flow controller 23 via the air valve 22. Thus, in the single heat source method or the electric spark method, a gas facility for ignition is always required, so that the equipment cost is increased.
[0010]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-323211
[Patent Document 2]
Japanese Patent Application Laid-Open No. 6-129627
[Problems to be solved by the invention]
The prior art described above has the following problems. The single heat source method has a problem that the heat supply is stopped due to disconnection and ignition and combustion cannot be performed. In addition, the electric spark system may not be able to ignite without being reliably sparked. Furthermore, although it is common to a single heat source and an electric spark, a gas facility for ignition is required, so that an equipment cost is required.
[0013]
An object of the present invention is to solve the above-mentioned problems of the prior art while using an electric heater as a heat source, and can be ignited and burned even if a disconnection occurs, and can be ignited reliably. that do not require gas installations for ignition is to provide an exhaust gas treatment apparatus.
[0014]
[Means for Solving the Problems]
1st invention is equipped with two or more heat sources which have an electric heating material, supplies air directly to these heat sources from the outside, and ignites and burns the combustible gas contained in exhaust gas combining the energy of these heat sources And the combustion of the combustible gas can be continued with the energy of at least one of these heat sources. Since ignition and combustion can be shared by two or more heat sources, a dedicated ignition facility is not required, and since the heat sources are multiplexed, even if one heat source is disconnected, combustion can be continued with other heat sources. Furthermore, since air is directly supplied to the heat source from the outside, the combustion efficiency of the combustible gas can be further increased.
[0015]
The second invention includes a combustion chamber for burning a combustible gas contained in exhaust gas, a combustible gas introduction pipe for introducing exhaust gas containing a combustible gas into the combustion chamber, an exhaust pipe for exhausting the combustion chamber, A cylindrical first heat source part communicating with the outlet of the combustible gas introduction pipe, a first electric heating material provided in the cylindrical first heat source part, and inserted into the cylinder of the first heat source part, A second heat source part that forms a gas flow path with the cylindrical first heat source part, a second electric heating material provided in the second heat source part, the outside of the combustion chamber, and the gas flow path communicate with each other. A first air intake passage that takes air into the gas flow path, and a second air intake passage that connects the outside of the combustion chamber and the vicinity of the cylinder port of the first heat source unit to take air into the vicinity of the cylinder opening, The first temperature detector for detecting the temperature of the first heat source unit, the second temperature detector for detecting the temperature of the second heat source unit, and the first heat source And as the second heat source is the set temperature, the control means based on the temperature detected by the first temperature detector and second temperature detector, and controls the power supplied to the first electrical heating member and the second electrical heating member Is an exhaust gas treatment apparatus.
[0016]
Since ignition and combustion can be shared by two or more heat sources, a dedicated ignition facility is not required and the configuration can be simplified. In addition, since the heat source is multiplexed and the power supplied to the electric heating material is individually controlled by the control unit, even if one heat source is disconnected, combustion can be continued with another heat source. The combustible gas is mixed with the air taken in from the air intake, ignited and burned in the combustion chamber by the heat of the heat source, and exhausted as exhaust gas from the exhaust pipe after combustion. The combustible gas given by combining the heat energy of the first heat source part and the second heat source part is mixed with air in the gas flow path and burned in the gas flow path. However, in the amount of air introduced from the air hole, The highly combustible gas that cannot be burned due to insufficient oxygen concentration burns above the first heat source part and the second heat source part in the combustion chamber having a higher oxygen concentration than in the gas flow path. The temperature of the first heat source unit and the second heat source unit can be individually detected. Since the electric power supplied to the first electric heating material and the second electric heating material is controlled based on the detected temperatures of the first temperature detector and the second temperature detector, the set temperature can be maintained. Furthermore, since air is directly supplied to the heat source from the outside, the combustion efficiency of the combustible gas can be further increased.
[0017]
A third invention is the exhaust gas processing apparatus according to the second invention, wherein the combustible gas introduction pipe, the first air intake passage, and the second air intake passage are integrally provided in the combustion chamber. If the combustible gas introduction pipe, the first air intake path, and the second air intake path are integrally provided in the combustion chamber, the configuration can be further simplified.
[0018]
A fourth invention is the exhaust gas processing apparatus according to the second or third invention, wherein a gap between the cylindrical first heat source part and the second heat source part is 2 to 20 mm. A gap of 2 to 20 mm is appropriate for the gas flow passage to make combustion effective.
[0019]
A fifth invention is the exhaust gas treatment apparatus according to the second or third invention, wherein the first heat source section has a cylindrical shape with an overall length of 30 to 300 mm. The total length is suitably in the range of 30 to 300 mm.
[0020]
A sixth invention is the exhaust gas processing apparatus according to the second or third invention, wherein the set temperature of the first heat source unit and the second heat source unit is approximately 800 ° C. About 800 ° C. has the highest combustion efficiency and is stable.
[0021]
A seventh invention is the exhaust gas processing apparatus according to the second or third invention, wherein a mixed gas flow rate of the combustible gas and the non-combustible gas of the exhaust gas is 5 to 200 L / min. The mixed gas flow rate is suitably in the range of 5 to 200 L / min.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[0023]
FIG. 1 shows an exhaust gas treatment apparatus of the present invention. The exhaust gas treatment apparatus includes a combustion chamber 1 that combusts a combustible gas contained in exhaust gas, and two or more heat chambers that are provided in the combustion chamber 1 to ignite the combustible gas and to release thermal energy for combustion. 30, temperature detection means (not shown) for detecting the temperature of the heat source 30, and a temperature controller 7 as a control unit for controlling the heat source 30 based on the detected temperature.
[0024]
The combustion chamber 1 is made of a heat-resistant member such as stainless steel and burns combustible gas inside. A combustible gas introduction pipe 8 is inserted into the combustion chamber from the lower part of the combustion chamber 1 to introduce exhaust gas containing a combustible gas into the combustion chamber 1. In the illustrated example, the combustible gas introduction pipe 8 has a vertical portion 8a and a horizontal portion 8b. The upper portion of the vertical portion 8a is inserted into the combustion chamber 1, and the horizontal portion 8b is an exhaust port of a semiconductor manufacturing apparatus (not shown). The exhaust gas containing the combustible gas discharged from the semiconductor manufacturing apparatus is introduced into the combustion chamber 1. Here, as the combustible gas discharged from a semiconductor manufacturing device, eg, H ₂ gas.
[0025]
An exhaust pipe 11 is provided in the upper part of the combustion chamber 1, and exhaust gas after burning combustible gas is released from the exhaust pipe 11 into the atmosphere.
[0026]
A cooling unit 9 that covers the upper inner wall of the combustion chamber 1 is provided so that the inner wall that is heated by being exposed to the flame 10 by combustion can be cooled. The cooling unit 9 may be configured by a cooling jacket that cools the wall surface by circulating a coolant such as water, or may be configured by simply coating the inner wall with a heat insulating material. The cooling unit 9 may be provided on the entire inner wall or outer wall of the combustion chamber.
[0027]
The multiple heat source 30 includes two or more heat source parts 2 and 3 made of a heat resistant member such as ceramic. Here, the first heat source unit 2 and the second heat source unit 3 are configured to have a coaxial double heat source structure.
[0028]
The first heat source section 2 arranged outside has a cylindrical shape with the same diameter as the combustible gas introduction pipe 8, is provided directly above the combustible gas introduction pipe 8, and communicates with the outlet 8c. . A first electric heater (not shown) as an electric heating material is provided in the cylindrical first heat source unit 2 so that the first heat source unit 2 can be heated. In order to provide the first electric heater inside the cylinder, the electric heater is embedded in the cylinder, or a cavity is formed in the first heat source section 2, and the electric heater is arranged in the cavity. Good. The electric heater can control the temperature of the first heat source unit 2 by the amount of electric power supplied thereto. Here, the electric heater is composed of, for example, a Kanthal wire.
[0029]
The second heat source section 3 disposed on the inside has a rod shape or a columnar shape (hereinafter simply referred to as a rod shape), and a combustible gas introduction pipe communicated with the first heat source section 2 from within the cylinder. A cylindrical gas flow path 27 is formed between the cylindrical first heat source unit 2 and the vertical part 8a of the combustible gas introduction pipe 8. The upper end of the second heat source unit 3 may be arranged so as to protrude slightly from the cylindrical port 3a of the first heat source unit, or may be set to the same height without protruding, or may be retracted, and the lower end thereof is a combustible gas introduction pipe 8 The vertical portion 8a is taken out of the tube. A second electric heater (not shown) similar to the first electric heater is provided in the rod-shaped second heat source unit 3 so that the second heat source unit 3 can be heated. In order to provide the second electric heater in the rod, the electric heater may be embedded in the rod, or a cavity may be formed in the second heat source unit 3, and the electric heater may be disposed in the cavity. The heat generating part of the rod-like second heat source part 3 may be the entire length of the second heat source part 3, but only the upper part overlapping at least the first heat source part 2 is sufficient. In this case, the electric heater may be disposed only on the upper part of the second heat source unit 3, and only the upper part constitutes the substantial second heat source unit 3.
[0030]
In addition, a low concentration air intake passage 4 for replenishing oxygen in the air as a combustion-supporting gas necessary for combustion of the low concentration combustible gas is provided in the lower part of the combustion chamber 1 in a tubular shape. The low-concentration air intake path 4 communicates the outside of the combustion chamber 1 with a gas flow path 27 formed between the first heat source unit 2 and the second heat source unit 3, and the outside of the combustion chamber 1. Then, the air is directly taken into the gas passage 27 through the low concentration air intake passage 4 and mixed with the exhaust gas introduced into the gas passage 27 through the combustible gas introduction pipe 8. ing. In order to facilitate mixing with the exhaust gas, a plurality of low concentration air intake passages 4 are provided along the peripheral wall of the combustion chamber 1. The total amount of oxygen supplied from the plurality of low-concentration air intake paths 4 is 0.5 m ³ / min.
[0031]
Since the pressure of the combustible gas flowing in the gas flow path 27 between the inner peripheral wall of the first heat source part 2 and the outer peripheral wall of the second heat source part 3 is lower than the outer peripheral pressure of the low concentration air intake path 4, Air is drawn into the gas channel 27 between the inner peripheral wall of the first heat source unit 2 and the outer peripheral wall of the second heat source unit 3, and flows through the gas channel 27.
[0032]
A high-concentration air intake passage 12 that replenishes oxygen in the air necessary for combustion of the high-concentration combustible gas is provided in a tubular shape on the outer periphery of the first heat source unit 2. The high concentration air intake path 12 communicates the outside of the combustion chamber 1 and the vicinity of the outlet 2 a of the cylindrical first heat source 2 inside the combustion chamber 1. The high-concentration air intake path 12 is configured to stand along the outer wall of the first heat source unit 2 so as to be separated from the outer wall of the first heat source, thereby also serving as heat insulation for the wall of the combustion chamber 1 of the first heat source unit 2. ing. High concentration flammable gas which takes in the atmosphere directly from the outside of the combustion chamber 1 through the high concentration air intake passage 12 to the vicinity of the outlet 2a and exits from the outlet 2a through the combustible gas introduction pipe 8 Is supposed to be mixed with. Further, in order to ensure that the air coming out from the outlet 28a of the high concentration air intake passage 12 and the high concentration combustible gas can be mixed, the intake passage 28 is narrowed from upstream to downstream. The flow rate is increased. In order to facilitate mixing with the high-concentration combustible gas, a plurality of high-concentration air intake passages 12 are provided along the peripheral wall of the combustion chamber 1. The total amount of oxygen supplied from the high-concentration air intake passage 12 is 2.5 m ³ / min.
[0033]
As described above, the double heat source 30 includes the two-stage air intake passages 4 and 28 for low concentration and high concentration.
[0034]
The temperature detector (not shown) includes a first temperature detector that detects the temperature of the first heat source unit 2 and a second temperature detector that detects the temperature of the second heat source unit 3. The first temperature detector and the second temperature detector are composed of, for example, a thermocouple, and are embedded in the first heat source unit 2 and the second heat source unit 3, respectively.
Two power cables 6 a and 6 b for supplying electric power to the first electric heater of the first heat source unit 2 are drawn out from the upper and lower portions of the cylindrical first heat source unit 2 and are passed through the lower part of the combustion chamber 1 through the temperature controller 7. Connected to. The two power cables 26 a and 26 b that supply power to the second electric heater of the second heat source unit 3 are both drawn from the lower end of the second heat source unit 3 and connected to the temperature controller 7.
[0035]
A cable 5 a for transmitting a temperature detection signal of the first temperature detector is drawn from a thermocouple embedded in the first heat source unit 2 and connected to the temperature controller 7 through the lower part of the combustion chamber 1. A signal cable 25 a for transmitting a temperature detection signal of the second temperature detector is drawn from the lower end of the rod-like second heat source unit 3 and connected to the temperature controller 7.
[0036]
The temperature controller 7 includes a first electric heater and a second electric heat based on the detected temperatures of the first temperature detector and the second temperature detector so that the first heat source unit 2 and the second heat source unit 3 reach a set temperature. The power to the heater is controlled.
[0037]
Hereinafter, the operation of the exhaust gas treatment apparatus will be described.
[0038]
An atmosphere in the combustion chamber 1 is sucked from the exhaust pipe 11 by gas suction means such as an exhaust facility (not shown) provided in the exhaust pipe 11, and the low concentration air intake passage 4 provided in the lower part of the combustion chamber 1 and the high By taking the atmosphere into the combustion chamber 1 from both the intake passages 12 and the concentration air intake passage 12, the atmosphere always flows in the combustion chamber 1 with individual replenishment amounts.
[0039]
An electric current is passed through the electric heaters of the first heat source unit 2 and the second heat source unit 3, and the first heat source unit 2 and the second heat source unit 3 are heated to the set temperature described above under the control of the temperature controller 7. As for the heating temperature, the mixed gas flowing through the gas flow path 27 formed between the first heat source unit 2 and the second heat source unit 3 is introduced from the combustible gas introduction pipe 8 without requiring an ignition gas such as hydrogen. The temperature should be sufficient for the combustible gas to be ignited directly.
[0040]
After the heating, the valve (not shown) of the combustible gas introduction pipe 8 is opened, and the exhaust port of the semiconductor manufacturing apparatus (not shown) and the combustible gas introduction pipe 8 are communicated with each other so that the exhaust gas discharged from the semiconductor manufacturing apparatus It introduces into the combustible gas introduction pipe 8. The exhaust gas rising up the gas flow path 27 is mixed with the air drawn in from the low concentration air intake path 4 provided in the gas flow path 27 on the way, and the temperature is controlled by the temperature controller 7 to be doubled. When passing through the gas flow path 27 heated by the combined heat energy of the heat source 30, the combustible gas reliably touches the heat source portions 2 and 3, and thus the combustion temperature is raised. For this reason, the combustible gas undergoes a combustion reaction in the gas flow path 27 and ignites and burns without requiring a separate gas ignition facility. The combustible gas is combusted by the high heat energy from the double heat source 30 and the oxygen of the air entering from the low concentration air intake passage 4, so that the combustible gas contained in the exhaust gas can be combusted efficiently even at a low concentration.
[0041]
The highly combustible gas cannot react only with oxygen taken into the gas flow path 27 from the low concentration air intake path 4 and comes out from the outlet 2a of the first heat source section 2 as unburned gas. In the vicinity of the outlet 2a, there is sufficient air taken into the combustion chamber 1 from the high-concentration air intake path 12, so that the highly combustible gas is sufficiently mixed with the air. . Moreover, in the vicinity of the outlet 2a, the first heat source unit 2 and the second heat source unit 3 are not only high in temperature but also heated by the flame 10 that burns in the gas flow path 27 and exits from the gas flow path port. Therefore, even a highly combustible gas is easily burned.
[0042]
The flow rate of the mixed gas of the combustible gas and the incombustible gas of the exhaust gas introduced into the combustion chamber 1 from the combustible gas introduction pipe 8 is suitably in the range of 5 to 200 L / min. When the mixed gas flow rate is less than 5 L / min, the combustion efficiency is poor. Conversely, if it exceeds 200 L / min, incomplete combustion is not preferable.
[0043]
Although the upper inner wall of the combustion chamber 1 is exposed to a high temperature due to the heat of the flame 10 due to the combustion, in the embodiment, the cooling unit 9 blocks the heat because the cooling unit 9 is provided on the upper inner wall. In order to prevent the inner wall from being exposed to high temperature, the side wall of the combustion chamber 1 is effectively protected from heat.
[0044]
High-temperature exhaust gas generated by combustion, non-combustible gas contained in the exhaust gas from the beginning, and excess air are released into the atmosphere from the exhaust pipe 11.
[0045]
Here, the gap between the cylindrical first heat source part 2 and the rod-like second heat source part 3 is suitably in the range of 2 to 20 mm. If the gap is less than 2 mm, the ventilation resistance increases, and air is not sufficiently taken in, resulting in incomplete combustion. On the other hand, if it exceeds 20 mm, a pressure difference does not occur and air is not taken into the flow path, and the combustion reaction does not occur.
[0046]
Moreover, the range of 30-300 mm is suitable for the full length of the cylindrical 1st heat-source part 2. As shown in FIG. When the total length is less than 30 mm, the air passing through the gas flow path is insufficiently heated, and thus combustion is incomplete. In addition, it is difficult to configure a heater commensurate with a length exceeding 300 mm.
[0047]
In addition, the set temperature of the first heat source unit 2 and the second heat source unit 3 is about 800 ° C. and has the highest combustion efficiency and is stable.
[0048]
Further, the flow rate of the mixed gas of the combustible gas H ₂ and noncombustible gas of N ₂ gas is preferably in the range of 5~200L / min. This is because a stable combustion reaction can be realized within this range.
[0049]
As described above, according to the embodiment, fresh outside air is directly taken in from the outside of the combustion chamber 1 through the low concentration air intake passage 4 in the narrow gas passage 27 heated at a high temperature by the double heat source 30. Since it is mixed with air and combusted, the combustible gas contained in the exhaust gas can be directly ignited and combusted directly without an ignition device using a combustion-supporting gas such as hydrogen. Therefore, since a combustion-supporting gas other than the atmosphere and an ignition device are not required, the device configuration can be greatly simplified. Moreover, since the high concentration air intake path 12 is configured to rise along the cylindrical outer wall of the first heat source section 2, it can block the thermal energy radiated from the multiple heat source 30 to the combustion chamber 1 wall. And the deterioration of the peripheral wall of the combustion chamber 1 can be effectively prevented.
[0050]
In addition, since the heat source is a double heat source 30 that can control power independently, unlike the single heat source method, even if one of the heat sources is disconnected, heat can be supplied with the other heat source, so combustion continues. it can. Therefore, even if the heat source is partially disconnected, unburned gas is not generated, and it is possible to effectively prevent dangerous unburned gas from being released from the exhaust pipe 11 into the atmosphere.
[0051]
In addition, since the heat source 30 has a double heat source structure in which the gas flow path 27 is formed inside, the combustion region is provided at two locations of the gas flow path 27 and the upper part of the heat source 30, and one gas flow path is provided. In 27, combustible gas with a low concentration can be combusted, and combustible gas with a high concentration can be combusted on the other heat source 30 upper part. Therefore, the combustible gas contained in the exhaust gas can be burned effectively regardless of the combustible gas concentration.
[0052]
In addition, since the high heat radiated from the combustion flame by the double heat source 30 to the combustion chamber peripheral wall is cut off by the cooling unit 9, the combustion chamber 1 can be effectively protected from high temperature. Moreover, since the heat source 30 is made of ceramic as a heat insulating material, unlike the conventional single heat source method, the electric heater provided in the heat source is difficult to break, and the operating temperature range is also limited. The upper limit can be up to 1000 ° C. as described above.
[0053]
In particular, in the electric spark method, if the concentration of the combustible gas reaches a high concentration when ignited, there is a problem that a malfunction phenomenon occurs. In the embodiment, however, ignition can be performed reliably. Such a problem will not occur. Further, since the burner electrode is not used, there is no problem that the electrode cannot be ignited and not ignited due to deterioration of the electrode. Furthermore, even if the flame 10 formed at the upper part of the heat source 30 fluctuates due to the pressure of the exhaust pipe 11, it does not burn at one place where the flame 10 is emitted as described above, but at other places. Since the combustible gas is combusted even in a certain gas flow path, the combustion efficiency is also stabilized.
[0054]
FIG. 4 shows a comparison of combustion efficiency data when a mixed gas of H ₂ gas and N ₂ gas is combusted using the dual heat source of the embodiment and the single heat source of the conventional example. Unprocessed data is also shown when no combustion treatment is performed. The horizontal axis indicates the mixing ratio (H ₂ / (H ₂ + N ₂ )%) of hydrogen (H ₂ ) and nitrogen (N ₂ ) flowing from the combustible gas introduction pipe 8 in the direction of introducing the combustible gas. H ₂ residual concentration (ppm) measured at the exhaust pipe is shown.
[0055]
Here, in the double heat source,
Gap between the cylindrical first heat source part and the rod-like second heat source part: 4 mm
Total length of the cylindrical first heat source part: 80 mm
Set temperature of the first heat source part and the second heat source part: 900 ° C.
Flow rate of mixed gas of combustible gas H ₂ and non-combustible gas N _{2 of} exhaust gas: 90 L / min
In the single heat source, the temperature of the heat source section is 900 ° C.
[0056]
In the case of a single heat source, the H ₂ residual concentration is low because it is sufficiently combusted with a mixed gas with a mixing ratio of 30% or more, but it is almost unburned with a low mixing ratio of less than 30%. The unburned gas is discharged from the exhaust pipe 11 as it is. Therefore, the combustion treatment efficiency of low concentration H ₂ is poor and there is a problem of safety. On the other hand, in the case of a double heat source, the peak of H ₂ residual concentration is around 10% of the mixing ratio and can be burned with high efficiency. Although the H ₂ residual concentration was 2000 ppm in the single heat source, the double heat source was reduced to 200 ppm, 1/10 of the single heat source, and the combustion efficiency was remarkably improved. Therefore, the combustion treatment efficiency of the low concentration H ₂ is improved and the safety problem is solved.
[0057]
In the embodiment, the heat source is configured with a double heat source, but may be configured with multiple heat sources. For example, the number of the second heat source units 3 inserted into the cylinder of the first heat source unit 2 may be multiplexed by arranging two or more instead of one, or two tubes of the first heat source unit 2 may be arranged. Multiple lines may be arranged by coaxial arrangement. Moreover, although the shape of one 1st heat-source part 2 which comprises the heat source 30 was made into the cylindrical shape, you may comprise the shape of the cylindrical 1st heat-source part 2 with polygons, such as a hexagon or an octagon.
[0058]
In the embodiment, the low- and high-concentration air intake passages 4 and 28 are provided in the combustion chamber 1 in a pipe shape. However, if the replenishment amount is the same, the air intake passages 4 and 28 are the pipes. For example, it may be configured as a cylindrical intake passage communicating along the periphery of the combustion chamber 1. In this case, the combustion chamber 1, the combustible gas introduction pipe 8, and the low and high concentration air intake passages 4 and 28 may be configured integrally.
[0059]
【The invention's effect】
According to the present invention, even if one of the two heat sources is stopped due to a disconnection, the other heat source can continue to function. Further, when the combustible gas and air reliably touch the heat source part, ignition and more efficient combustion can be performed more reliably. Furthermore, since no gas equipment for ignition is required, the apparatus can be simplified.
[Brief description of the drawings]
FIG. 1 shows an exhaust gas treatment apparatus using a multiple heat source according to an embodiment, wherein (a) is a front sectional view and (b) is a side view.
FIG. 2 is a partial cross-sectional view of an exhaust gas treatment apparatus using a conventional single heat source.
FIGS. 3A and 3B are explanatory views of a conventional exhaust gas treatment apparatus using an electric spark, in which FIG. 3A is a partial front sectional view, and FIG. 3B is a partial side sectional view.
FIG. 4 is a H ₂ residual concentration characteristic chart comparing combustion efficiencies of a single heat source and a double heat source.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Combustion chamber 2 1st heat-source part 3 2nd heat-source part 4 Low concentration air intake path 7 Temperature controller (control part)
8 Combustible gas introduction pipe 8c Outlet of the combustible gas introduction pipe 10 Flame 11 Exhaust pipe 12 High concentration air intake path 30 Double heat source

Claims (2)

A combustion chamber for burning the combustible gas contained in the exhaust gas;
  A combustible gas introduction pipe for introducing exhaust gas containing combustible gas into the combustion chamber;
  An exhaust pipe for exhausting the combustion chamber;
  A cylindrical first heat source connected to the outlet of the combustible gas introduction pipe;
  A second heat source part that is inserted into the cylinder of the first heat source part to form a gas flow path between the first heat source part and the cylindrical first heat source part;
  A first air intake path that communicates the outside of the combustion chamber and the gas flow path to take air into the gas flow path;
  A second air intake passage that communicates the outside of the combustion chamber and the vicinity of the cylinder port of the first heat source unit to take air into the vicinity of the cylinder port;
  Control means for controlling electric power so that the first heat source unit and the second heat source unit are at a set temperature;
An exhaust gas treatment apparatus comprising: The exhaust gas treatment apparatus according to claim 1, wherein the combustible gas introduction pipe, the first air intake path, and the second air intake path are integrally provided in the combustion chamber.

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