JP2004225988A - Exhaust gas treating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust gas treating device capable of performing the combustion even when the disconnection occurs, surely performing the ignition without using a gas apparatus for ignition, and discharging a combustion gas of a low temperature. <P>SOLUTION: This exhaust gas treating device comprises a flammable gas introduction pipe 8, an exhaust pipe 11, and an air take-in port 12 in the combustion chamber 1, a blower fan 20 as a gas sucking means for sucking the combustion chamber and introducing the flammable gas and the atmospheric air into the combustion chamber, a multiple heat source 30 mounted in the combustion chamber for igniting and combusting the flammable gas, and a cooling radiator 19 as a cooling means mounted between the combustion chamber 1 and the waste pipe 11 for cooling the combustion gas of high temperature. The multiple heat source 30 is composed of a cylindrical first heat source part communicated with the flammable gas introduction pipe 8 and heated by a heater, a second heat source part inserted into a cylinder of the first heat source part, forming a gas channel with the first heat source part and heated by the heater, and an air hole 4 formed on the first heat source part and introducing the air from the air take-in port 12 of the combustion chamber to the gas channel. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an exhaust gas treatment device that burns combustible gas contained in exhaust gas discharged from a semiconductor manufacturing device or the like, and is particularly suitably used when the combustible gas is hydrogen (H ₂ ).
[0002]
[Prior art]
Exhaust gas discharged from manufacturing equipment such as semiconductor manufacturing equipment and liquid crystal manufacturing equipment often contains toxic combustible gas, and cannot be released to the atmosphere as it is. Therefore, a combustible gas is combusted by a heat source before being released into the atmosphere using an exhaust gas treatment device. BACKGROUND ART Conventionally, exhaust gas treatment apparatuses include a gas burner method (for example, see Patent Document 1) and an electric spark ignition and combustion method (for example, see Patent Document 2) according to the type of heat source.
[0003]
FIGS. 3A and 3B show an exhaust gas treatment apparatus using a gas burner method, wherein FIG. 3A is a partial side sectional view of the apparatus, and FIG. 3A is a system configuration diagram of the apparatus.
[0004]
As shown in FIG. 3A, the exhaust gas treatment device has a combustion chamber 1 for burning combustible gas. The combustion chamber 1 is provided in a housing 31 provided with an air intake 12 for taking in cooling air. A flammable gas introduction pipe 8 and an exhaust pipe 11 are connected to the combustion chamber 1 so as to exhaust burned exhaust gas while introducing flammable gas. A gas burner 13 is provided in the combustion chamber 1, and compressed gas is supplied from a compressed air pipe 14 to the gas burner 13, and a combustion gas such as propane gas is supplied from a gas cylinder 15 to the gas burner 13. The flame 10 is formed by ignition and burning. On the downstream side of the flame 10 in the combustion chamber 1, an air hole for taking in the cooling air in the housing 31 is provided at a position in contact with the arrow.
[0005]
As shown in FIG. 3B, the exhaust gas treatment system includes an exhaust gas treatment device having a dry pump unit 17 and a housing 31 and a scrubber unit 18 having a blower fan 16 for reducing pressure. The flammable gas is supplied from the flammable gas introduction pipe 8 to the exhaust gas combustion device by the dry pump unit 17. Exhaust gas after combustion by the exhaust gas combustion device is sucked from the exhaust pipe 11 by the blower fan 16 provided in the scrubber unit 18, component-adjusted by the scrubber, and released to the atmosphere.
[0006]
In the configuration described above, the combustible gas is burned by passing the combustible gas through the flame 10 obtained by burning the combustion gas or the like with the gas burner 13. The exhaust gas after combustion is cooled by cooling air flowing from an air hole provided at a position where the arrow contacts, is diluted, and is discharged from the exhaust pipe 11 to the atmosphere.
[0007]
In this apparatus, a combustion gas other than a flammable gas is used as an ignition raw material. Therefore, maintenance of a combustion gas such as propane gas in the apparatus is frequent and needs to be replaced as needed. Further, since it is necessary to provide a blower fan for drawing exhaust gas into the scrubber downstream of the scrubber, a scrubber unit is required separately from the exhaust gas treatment device. In addition, since the flammable gas cannot be introduced into the combustion chamber depending on the blower fan that is sucked through the scrubber, a dry unit pump for introducing the flammable gas into the combustion chamber is also required, so equipment costs are reduced. Go up.
[0008]
FIGS. 4A and 4B show an exhaust gas treatment apparatus using an electric spark system, wherein FIG. 4A is a front sectional view of the apparatus, and FIG. 4B is a side sectional view of the apparatus. The basic configuration is the same as the gas burner system shown in FIG. The difference is that the ignition and combustion are performed by an electric spark instead of the gas burner. The configuration of the electric spark is such that burner electrodes 28 and 28 are connected to a step-up transformer 26 for increasing the voltage, and spark is generated by a high voltage.
[0009]
By sucking air from the exhaust pipe 11, air is taken into the combustion chamber 1 from a large number of air intake ports 12, and air is constantly flowed into the combustion chamber 1. Hydrogen (H ₂ ) gas flows from the ignition gas pipe 24 into the combustion chamber 1 in which air is constantly flowing, and reacts with oxygen in the atmosphere by the energy of an electric spark to ignite hydrogen. After the ignition, the exhaust gas flows from the combustible gas introduction pipe 8 into the combustion chamber 1 to be mixed with the oxygen in the atmosphere, and the combustible gas contained in the exhaust gas is burned by the flame of the ignition, thereby performing the combustion treatment of the exhaust gas.
[0010]
However, if the ignition is not possible, the electric spark repeatedly sparks, and if the concentration of the flammable gas reaches an abnormally high concentration at the time of ignition, a problem may occur. In addition, the electric spark is not reliably generated due to the deterioration of the burner electrode 25, and ignition may not be performed. The flame 10 after ignition fluctuates due to the pressure of the exhaust pipe 11, and the combustion efficiency becomes unstable. Furthermore, when the pressure is reduced, the ignition gas is ignited, so that there is a problem that necessary oxygen in the air is insufficient and the ignition cannot be performed.
[0011]
[Patent Document 1]
JP-A-62-134414
[Patent Document 2]
JP-A-6-129627
[Problems to be solved by the invention]
The prior art described above has the following problems. In the gas burner method, maintenance is frequent, and it is necessary to add a unit separate from the combustion device in order to reduce the pressure. Further, the electric spark method has a disadvantage that the pressure cannot be reduced. In the exhaust gas treatment device, generally, reducing the pressure in the combustion chamber is disadvantageous to combustion, but reducing the pressure in the combustion chamber is a user's request, and it is desired to realize an exhaust gas treatment device that meets this request.
[0014]
An object of the present invention is to solve the above-mentioned problems of the prior art, facilitate maintenance, eliminate the need for a separate unit to reduce the pressure, and provide an exhaust gas treatment apparatus that does not cause ignition failure even when the pressure is reduced. To provide.
[0015]
Means and action for solving the problem
According to a first aspect of the present invention, there is provided a combustion chamber, 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, and an air intake for taking air into the combustion chamber. Gas inlet means provided in the exhaust pipe, for introducing the combustible gas from the combustible gas introduction pipe into the combustion chamber by sucking the combustion chamber, and introducing the atmosphere from the air intake port; A multiple heat source provided in the combustion chamber for igniting and burning flammable gas contained in the exhaust gas; and a cooling means provided between the combustion chamber and the exhaust pipe for cooling high-temperature exhaust gas generated by combustion. Wherein the multiple heat sources are connected to an outlet of the flammable gas introduction pipe in a cylindrical first heat source section; a first electric heater provided in the cylindrical first heat source section; A first heat source unit which is inserted into a tube of the heat source unit and has a cylindrical shape; A second heat source section forming a gas flow path therebetween, a second electric heater provided in the second heat source section, and taken into the combustion chamber from the air intake port provided in the first heat source section. And an air hole for introducing air into the gas flow path.
[0016]
By using a multiple heat source structure for the heat source, it is possible to prevent the combustion efficiency of the combustible gas from lowering even if the pressure in the combustion chamber is reduced. Further, since a heat source using an electric heater is used, frequent replacement of the gas cylinder is not required unlike the gas burner method, and maintenance is facilitated. In addition, since the combustible gas can be ignited directly in the gas flow path by the energy and air from the multiple heat sources, the apparatus can be simplified without the need for an ignition gas facility. Furthermore, since the exhaust gas after combustion is cooled by the cooling means and unnecessary components are removed by the cooling means, the combustion gas can be released to the atmosphere without a scrubber. Since a scrubber is not required, the combustible gas can be introduced into the combustion chamber by the gas suction means without requiring a dry pump unit.
[0017]
According to a second aspect of the present invention, in the first aspect, a meandering shape is provided between the combustion chamber and the exhaust pipe, which descends along the combustion chamber from above the combustion chamber and connects to the exhaust pipe standing upright in parallel with the combustion chamber. A flue gas treatment apparatus comprising a bent connection pipe, and the connection pipe provided with the cooling means. Since the cooling means is provided in the connection pipe bent in a meandering shape, a sufficient cooling length can be provided, and the combustion gas having a high temperature can be effectively cooled. Further, since the connecting pipe is meandering, the height of the apparatus can be suppressed.
[0018]
According to a third aspect, in the first or second aspect, gas suction control means for controlling gas suction means is provided, and an amount of air taken into the combustion chamber from the air intake can be adjusted. Features. By adjusting the amount of air taken into the combustion chamber from the air intake, the combustion efficiency of combustible gas can be improved.
[0019]
In a fourth aspect based on the first to third aspects, the pressure in the combustion chamber reduced by the gas suction means is from atmospheric pressure to -1500 Pa. Even if the pressure in the combustion chamber is in the range of atmospheric pressure to -1500 Pa, the combustible gas can be stably burned.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0021]
FIG. 1 shows an exhaust gas treatment apparatus according to an embodiment, in which (a) is a front sectional view and (b) is a side view.
[0022]
The exhaust gas treatment device includes a combustion chamber 1, a housing 31 that houses the combustion chamber 1, and a control chamber 21 provided below the housing 31. The control room 21 houses a power supply, a temperature controller, a suction unit controller, and the like. The housing 31 is provided with an opening (not shown) communicating with the outside air in order to make the inside of the housing 31 an atmospheric atmosphere.
[0023]
The combustion chamber 1 is provided with a flammable gas introduction pipe 8 inserted through a housing 31 to introduce exhaust gas containing flammable gas into the combustion chamber 1. An air intake 12 for taking in the atmosphere is provided at a lower portion of the combustion chamber 1.
[0024]
Further, a multiple heat source 30 heated by an electric heater is provided in the combustion chamber 1 so as to ignite the combustible gas contained in the exhaust gas and burn the combustible gas. The multiple heat source 30 is inserted into a cylindrical first heat source unit (shown as an external appearance of the multiple heat source 30) communicating with the outlet of the combustible gas introduction pipe 8, and is inserted into a cylinder of the first heat source unit. A second heat source (not shown) that forms a gas flow path (not shown) between the first heat source and a cylindrical first heat source; And an air hole 4 for introducing the taken air into the gas flow path.
[0025]
Further, the combustion chamber 1 communicates with an exhaust pipe 11 for discharging the atmospheric gas in the combustion chamber 1. For example, a cooling radiator 19 is provided in front of the exhaust pipe 11 as cooling means for cooling the exhaust gas after combustion, and cools gas containing high-temperature combustion gas generated by combustion. The cooling radiator 19 is provided on a connection pipe 22 provided between the exhaust pipe 11 and the combustion chamber 1. The connection pipe 22 is bent in a meandering shape. That is, the connecting pipe 22 is lowered from the upper part of the combustion chamber 1 along the combustion chamber 1 while being separated from the combustion chamber 1, and is connected to the lower part of the exhaust pipe 11 which stands upright in parallel with the combustion chamber 1. ing. A blower fan 20 as a gas suction means for reducing pressure is provided below or on the exhaust pipe 11. The blower fan 20 sucks the inside of the combustion chamber 1 through a connection pipe 22 and enters the combustion chamber 1 from the flammable gas introduction pipe 8. Along with introducing the combustible gas, the atmosphere is introduced from the air intake port 12. The air intake amount of the blower fan 20 can be adjusted by a suction means controller provided in the control room 21.
[0026]
The combustion chamber 1, the cooling radiator 19, the blower fan 20, and the like are supported on the control chamber 21 by a plurality of support legs 23.
[0027]
According to such a configuration, the heat source 30 has a multiple heat source structure, so that even if one of the heat sources stops functioning due to disconnection, the other heat source can continue to function. In addition, since the combustible gas surely touches the heat source portion, ignition can be reliably performed, and highly efficient combustion can be performed. In addition, since the combustible gas can be ignited directly in the gas flow path by the energy and air from the multiple heat sources 30, the apparatus can be simplified without the need for an ignition gas facility. Further, since the high-temperature combustion gas is cooled by the cooling radiator 19, it is possible to prevent the combustion gas from being released to the atmosphere at a high temperature. In addition, since the cooled combustion gas is released from the exhaust pipe 11, the exhaust pipe 11 can be prevented from being heated to a high temperature, and safety can be improved.
[0028]
Further, since the cooling radiator 19 is provided on the connection pipe 22 bent in a meandering shape, a sufficient cooling length can be obtained, and the combustion gas having a high temperature can be effectively cooled. Moreover, since the connecting pipe 22 is meandering, the height of the combustion device can be reduced.
[0029]
FIG. 2 shows a detailed view of the combustion chamber 1 housed in the housing 31 and its surroundings. Two or more combustion chambers 1 are provided in the combustion chamber 1, and a heat source 30 that ignites the combustible gas and emits thermal energy for burning, and a temperature detection unit (not shown) that detects 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.
[0030]
The combustion chamber 1 is made of a heat-resistant metal member such as stainless steel, for example, and burns combustible gas inside. A flammable gas introduction pipe 8 is inserted into the combustion chamber 1 from below the combustion chamber 1 to introduce exhaust gas containing flammable gas into the combustion chamber 1. The combustible gas introduction pipe 8 has a vertical portion 8a and a horizontal portion 8b, and an upper portion of the vertical portion 8a is inserted into the combustion chamber 1, and the horizontal portion 8b is connected to an exhaust port of a semiconductor manufacturing apparatus (not shown). An exhaust gas containing a combustible gas discharged from a semiconductor manufacturing apparatus is introduced into the combustion chamber 1. Here, the combustible gas discharged from the semiconductor manufacturing apparatus is, for example, H ₂ gas.
[0031]
An exhaust pipe 11 is provided at an upper portion of the combustion chamber 1 so as to release an atmosphere in the combustion chamber 1 including an exhaust gas obtained by burning a combustible gas to the atmosphere.
[0032]
A plurality of air intakes 12 are provided on the outer periphery of the lower part of the combustion chamber 1 into which the combustible gas introduction pipe 8 is inserted, and the atmosphere (air) as a supporting gas is introduced into the combustion chamber 1 from outside the combustion chamber 1. ) Can be imported.
[0033]
A cooling unit 9 is provided to cover the upper inner wall of the combustion chamber 1 where the flame 10 is generated, so that the side wall 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 circulates a coolant such as water to cool the wall surface, 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 1.
[0034]
The heat source 30 includes two or more heat source units 2 and 3. Here, the first heat source unit 2 and the second heat source unit 3 have a double heat source structure coaxially arranged.
[0035]
The first heat source section 2 disposed outside has a cylindrical shape having the same diameter as the combustible gas introduction pipe 8, is provided directly above the combustible gas introduction pipe 8, and has an outlet 8 c (a horizontal line is drawn). Shown). A first electric heater (not shown) is provided inside 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 in the cylinder, the electric heater may be embedded in the cylinder, or a cavity may be formed in the first heat source unit 2, and the electric heater may be provided in the cavity. The electric heater can control the temperature of the first heat source section 2 by the amount of electric power supplied thereto. Here, the electric heater is made of, for example, Kanthal wire.
[0036]
The second heat source portion 3 disposed inside has a rod shape or a column shape (hereinafter, simply referred to as a rod shape), and a flammable gas introducing pipe communicating from inside the cylinder of the first heat source portion 2 to the second heat source portion 3. 8 is formed across the vertical portion 8a of the tube 8, and forms a cylindrical gas flow path 27 for flowing gas between the first cylindrical heat source portion 2 and the vertical portion 8a of the combustible gas introduction pipe 8. The upper end of the second heat source section 3 may be arranged so as to slightly protrude from the cylindrical port (gas flow path port) of the first heat source section 2 or may have the same height without protruding. Is taken out of the tube from the vertical portion 8a. A second electric heater (not shown) similar to the first electric heater is provided inside the rod-shaped second heat source section 3 so that the second heat source section 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 section 3, and the electric heater may be provided in the cavity. The heat-generating portion of the rod-shaped second heat source portion 3 may be the entire length of the second heat source portion, but may be at least the upper portion overlapping the first heat source portion 2. In this case, the electric heater only needs to be provided above the second heat source unit 3, and only the upper portion substantially constitutes the second heat source unit 3.
[0037]
In addition, an air hole 4 is provided in a lower part of the cylindrical wall of the first heat source part 2, and air taken into the combustion chamber 1 from an air intake port 12 provided in a lower part of the combustion chamber 1 is supplied to the first heat source part 2 and the first heat source part 2. The gas is taken into the gas flow path 27 formed between the heat source 3 and the heat source section 3, and is mixed with the exhaust gas introduced into the gas flow path 27 through the combustible gas introduction pipe 8. In order to facilitate mixing with the exhaust gas, a plurality of air holes 4 are provided along the outer periphery of the cylindrical wall of the first heat source unit 2.
[0038]
Since the pressure of the combustible gas flowing through the gas flow path 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 becomes lower than the outer peripheral pressure of the air hole 4, Air flows in the gas flow path 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.
[0039]
The temperature detector (not shown) includes a first temperature detector (not shown) for detecting the temperature of the first heat source unit 2 and a second temperature detector (not shown) for detecting the temperature of the second heat source unit 3. Z). The first temperature detector and the second temperature detector are formed of, for example, thermocouples, and are embedded in the first heat source unit 2 and the second heat source unit 3, respectively.
[0040]
Two power cables 6a and 6b for supplying power to the first electric heater of the first heat source 2 are drawn out from the upper and lower portions of the cylindrical first heat source 2 and passed through the lower portion of the combustion chamber 1 to the temperature controller 7. Connected to. The two power cables 26 a and 26 b for supplying power to the second electric heater of the second heat source unit 3 are both drawn out from the lower end of the second heat source unit 3 and connected to the temperature controller 7.
[0041]
A cable 5 a for transmitting a temperature detection signal of the first temperature detector is drawn out from a thermocouple embedded in the first heat source unit 2 through an air hole 4 and connected to a temperature controller 7 through a lower portion of the combustion chamber 1. The cable 6 b for transmitting the temperature detection signal of the second temperature detector is drawn out from the lower end of the rod-shaped second heat source unit 3 and connected to the temperature controller 7.
[0042]
The temperature controller 7 controls the first electric heater and the second electric heater 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 the set temperature. The power to the heater is controlled.
[0043]
Next, the operation of the exhaust gas treatment device configured as described above will be described.
[0044]
The atmosphere in the combustion chamber 1 is suctioned from the exhaust pipe 11 by the blower fan 20, and the air in the housing 31 is taken into the combustion chamber 1 from the air intake port 12 provided in the lower part of the combustion chamber 1. The air whose flow rate is controlled is always allowed to flow in 1. A desired reduced pressure state is created in the combustion chamber 1 by controlling the air volume of the blower fan 20 by the suction means controller.
[0045]
An electric current is supplied to each of 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 above-mentioned set temperature under the control of the temperature controller 7. The heating temperature is such that the mixed gas flowing through the gas flow path 27 formed between the first heat source section 2 and the second heat source section 3 is introduced from the flammable gas introduction pipe 8 without requiring an ignition gas such as hydrogen. Temperature sufficient to cause the flammable gas to ignite directly.
[0046]
After the heating, the valve (not shown) of the flammable gas introduction pipe 8 is opened, and the exhaust port of the semiconductor production apparatus (not shown) communicates with the flammable gas introduction pipe 8. Is introduced into the combustible gas introduction pipe 8. Since the pressure in the combustion chamber 1 is controlled to be reduced, the combustible gas can be introduced into the combustion chamber 1 without a dry pump. Exhaust gas rising through the gas flow path 27 in the heat source 30 via the flammable gas introduction pipe 8 entrains the combustion chamber 1 on the way from the air hole 4 provided in the first heat source unit 2 with a controlled air volume. When passing through the gas flow path 27 heated by the heat energy of the dual heat source 30 temperature-controlled by the temperature controller 7 when mixed with the air in the inside, the combustible gas surely touches the heat source units 2 and 3 , The combustion temperature is raised. For this reason, the combustible gas generates a combustion reaction in the gas flow path 27 in a reduced pressure state, and ignites and burns, without requiring a separate ignition device. Since the combustible gas is burned by the high heat energy of the dual heat source 30 and the oxygen of the air entering from the air holes 4, the combustible gas contained in the exhaust gas can be burned efficiently even at a low concentration of the combustible gas.
[0047]
The high-concentration combustible gas cannot react only with oxygen taken into the gas flow path 27 from the air hole 4, and comes out from the outlet 2a of the first heat source unit 2 as unburned gas. In the vicinity, there is sufficient air taken into the combustion chamber from the air intake port 12, so that the highly concentrated combustible gas is sufficiently mixed with the air. Moreover, in the vicinity of the outlet 2a, the first heat source 2 and the second heat source 3 are not only heated to a high temperature, but also heated by the flame in the gas flow passage 27 which burns out from the flow passage opening. Even highly combustible gas can be easily burned.
[0048]
If the mixed gas flow rate of the combustible gas and the non-combustible gas of the exhaust gas introduced from the combustible gas introduction pipe 8 into the combustion chamber 1 is in the range of 5 to 200 L / min, stable combustion can be realized.
[0049]
Although the upper inner wall of the combustion chamber 1 is exposed to high temperature by the heat of the flame 10 due to this combustion, in the embodiment, the cooling unit 9 is provided on the upper inner wall, so that the cooling unit 9 shuts off the heat. In order to prevent the inner wall from being exposed to high temperatures, the side wall of the combustion chamber 1 is effectively protected from heat.
[0050]
The high-temperature exhaust gas generated by the combustion, the high-temperature non-flammable gas contained in the exhaust gas from the beginning, and the excess high-temperature air are provided in the connection pipe 22 in the process of being discharged from the connection pipe 22 in the upper part of the combustion chamber 1. It is cooled by the cooled radiator 19. By this cooling, the gas temperature of about 200 ° C. is cooled to about 40 ° C., and unnecessary gas components are fixed to the inner wall of the connection pipe 22, so that the exhaust gas is diluted. The cooled gas is released from the exhaust pipe 11 to the atmosphere.
[0051]
Here, the gap between the cylindrical first heat source 2 and the rod-shaped second heat source 3 is preferably in the range of 2 to 20 mm in order to make combustion effective. When the gap is less than 2 mm, the air is not sufficiently taken in and the combustion is incomplete. Conversely, if it exceeds 20 mm, a pressure difference will not be generated, and air will not be taken into the gas flow path 27 and will not burn.
[0052]
The total length of the first cylindrical heat source 2 is preferably in the range of 30 to 300 mm. If the total length is less than 30 mm, the heating of the air drawn into the gas passage 27 is insufficient, so that the combustion is incomplete. Conversely, if it exceeds 300 mm, it is not preferable because the size is increased.
[0053]
Further, the set temperature of the first heat source unit 2 and the second heat source unit 3 controlled by the temperature controller 7 is suitably in the range of 650 to 1000 ° C. If the temperature is lower than 650 ° C., the combustion becomes incomplete and H ₂ and O ₂ do not react. Further, it is difficult to realize a heat source that generates a temperature exceeding 1000 ° C. and a combustion chamber structure that can withstand the temperature.
[0054]
Further, the flow rate of the mixed gas of the combustible gas and the noncombustible gas in the exhaust gas is suitably in the range of 5 to 200 L / min. If 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 preferred.
[0055]
As described above, according to the embodiment, instead of the gas burner method that requires frequent replacement of the gas cylinder as the heat source, the electric heater double heat source method that does not require the gas cylinder for the combustion gas is adopted. The maintenance cycle can be improved as compared with the gas burner method.
[0056]
In addition, the use of a dual heat source reduces the size of the combustion chamber, and the meandering cooling radiator 19 provided in the housing increases the space in the housing. The pressure reducing blower fan 20 can be provided in the housing 31 without the need.
[0057]
In addition, since the exhaust gas after combustion is cooled to fix unnecessary components in the exhaust gas to the inner wall of the exhaust pipe, the installation of the scrubber can be omitted, so that a blower fan for the scrubber becomes unnecessary. . Therefore, it is possible to provide a blower fan in the exhaust gas treatment device, and it is not necessary to separately add a unit for reducing the pressure. Further, the combustible gas can be introduced into the combustion chamber without the need for a dry pump unit by the blower fan provided in the exhaust gas treatment device. Therefore, the device can be simplified and the device cost can be reduced.
[0058]
Also, instead of the electric spark method that requires ignition equipment, a dual heat source method that does not require ignition equipment is used, so even if the pressure is reduced, the ignition gas ignites and is necessary for the combustion of flammable gas. The problem of insufficient oxygen in the air is eliminated, and low-concentration combustible gas can be efficiently burned even under reduced pressure.
[0059]
Further, according to the embodiment, the combustible gas is mixed with air and burned in the narrow gas passage 27 which is heated at a high temperature by the dual heat source. The combustible gas contained in the exhaust gas can be ignited and burned directly without a gas facility. Accordingly, since a non-atmospheric combustion supporting gas or ignition gas equipment is not required, the configuration of the apparatus can be greatly simplified.
[0060]
Further, since the heat source is a dual heat source 30 that can be independently controlled in power, unlike the single heat source method, even if one of the heat sources is disconnected, the remaining heat source can supply heat, so that combustion is continued. it can. Therefore, even if the heat source is partially disconnected, no unburned gas is generated, and it is possible to effectively prevent the dangerous unburned gas from being released from the exhaust pipe 11 to the atmosphere.
[0061]
Further, since the heat source 30 is a double heat source having the gas flow path 27 formed therein, the combustion area is provided at two places, the gas flow path 27 and the upper part of the heat source 30. Thus, combustible gas having a low concentration can be burned, and combustible gas having a high concentration can be burned above the other heat source 30. Therefore, the combustible gas contained in the exhaust gas can be effectively burned regardless of the combustible gas concentration. Further, even if the pressure in the combustion chamber 1 is reduced, ignition / combustion problems do not occur.
[0062]
Further, since the high heat radiated to the peripheral wall of the combustion chamber from the flame 10 generated by the double heat source 30 is blocked by the cooling unit 9, the combustion chamber 1 can be effectively protected from high temperatures. Therefore, the electric heater serving as the heat source in the combustion chamber 1 is hardly disconnected by the deterioration of the peripheral wall of the combustion chamber 1 due to the high-temperature combustion and the reaction heat due to the high-temperature combustion, and the operating temperature range is not limited. As mentioned above, it is possible up to 1000 ° C.
[0063]
In addition, in the electric spark method, if the concentration of the flammable gas reaches a dangerous concentration at the time of ignition, there is a problem that a malfunction phenomenon occurs, but in the embodiment, ignition can be performed reliably. Such a problem does not arise. In addition, since the burner electrode is not used, there is no problem that electric spark is not caused due to deterioration of the electrode and ignition cannot be performed. Furthermore, even if the flame 10 formed above the heat source 30 fluctuates due to the pressure of the exhaust pipe 11, the flame 10 is not burned at only one place where the flame 10 is emitted as described above, but is burned at another place. Since the combustible gas is burning even in a certain gas passage, the combustion efficiency is stabilized.
[0064]
As described above, according to this embodiment, since the pressure in the combustion chamber the combustion is also hydrogen H ₂ and vacuum to atmospheric pressure ~-1500 Pa can be maintained stably, to sufficiently meet the vacuum requirements from a user be able to.
[0065]
In the embodiment, the heat source is constituted by the double heat source, but may be constituted by the 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 is not one, but may be multiplexed by arranging two or more. Multiplexing may be performed by arranging more than one coaxial. Further, although the shape of the first heat source 2 constituting the heat source 30 is cylindrical, the shape of the cylindrical first heat source 2 may be polygon such as hexagon or octagon.
[0066]
Further, in the embodiment, the air intake port 12 is provided at the bottom of the combustion chamber 1, but may be provided at the outer periphery of the combustion chamber 1 or at both the bottom and the outer periphery of the combustion chamber. In the case where the air intake port 12 is provided in the outer peripheral portion, the air intake port 12 provided in the outer peripheral portion may be provided in a portion corresponding to the outlet of the gas flow path 27. In addition, although a blower fan has been described as a suction unit for creating a reduced pressure state in the combustion chamber, the present invention is not limited to this, and a reduced pressure pump or a vacuum pump may be used. Further, although the cooling unit is constituted by the cooling radiator, the cooling unit may be constituted by winding a coil-shaped copper pipe around the connection pipe and allowing the refrigerant to flow therethrough.
[0067]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, maintenance can be facilitated, a separate unit is not required for depressurization, and it can be prevented that an ignition failure does not occur even if depressurized. Therefore, reliable ignition and highly efficient combustion can be realized.
[Brief description of the drawings]
FIG. 1 is an overall sectional view of an exhaust gas treatment apparatus using a multiple heat source according to an embodiment.
FIG. 2 is a detailed view of a combustion chamber and its periphery according to the embodiment.
FIG. 3 is a partial cross-sectional view of a conventional exhaust gas treatment apparatus using a gas burner method.
4A and 4B are explanatory views of a conventional exhaust gas treatment apparatus using an electric spark system, in which FIG. 4A is a partial front sectional view, and FIG. 4B is a partial side sectional view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Combustion chamber 4 Air hole 8 Flammable gas introduction pipe 11 Exhaust pipe 12 Air intake 19 Cooling radiator (cooling means)
20 blower fan (gas suction means)
30 multiple heat sources

Claims (4)

A combustion chamber for burning combustible gas contained in the exhaust gas,
A flammable gas introduction pipe for introducing exhaust gas containing flammable gas into the combustion chamber,
An exhaust pipe for exhausting the combustion chamber;
A cooling means provided between the combustion chamber and the exhaust pipe, for cooling high-temperature exhaust gas generated by combustion, and an air intake for taking air into the combustion chamber,
Gas suction means provided in the exhaust pipe, introducing a combustible gas from the combustible gas introduction pipe into the combustion chamber by reducing the pressure in the combustion chamber by suction, and introducing air from the air intake port,
A multiple heat source provided in the combustion chamber for igniting and burning combustible gas contained in the exhaust gas,
With
A first heat source having a tubular shape, wherein the multiple heat sources communicate with an outlet of the flammable gas inlet tube; a first electric heater provided on the first heat source having a tubular shape; and a tube of the first heat source portion. A second heat source portion inserted into the first heat source portion and forming a gas flow path between the first heat source portion and the second heat source portion provided in the second heat source portion; And an air hole provided to introduce the air taken into the combustion chamber from the air intake port into the gas flow path. Between the combustion chamber and the exhaust pipe, there is provided a connection pipe bent down in a meandering shape, which descends along the side wall of the combustion chamber from the upper part of the combustion chamber and extends to an exhaust pipe standing upright in parallel with the combustion chamber. The exhaust gas treatment device according to claim 1, wherein the cooling means is provided in the connection pipe. The exhaust gas treatment apparatus according to claim 1 or 2, further comprising a gas suction control means for controlling the gas suction means, wherein an amount of air taken into the combustion chamber from the air intake is adjustable. 4. The exhaust gas treatment apparatus according to claim 1, wherein the pressure in the combustion chamber reduced by the gas suction means is from atmospheric pressure to -1500 Pa.

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