JP6641850B2 - Exhaust gas sampling device - Google Patents

Description

  The present invention relates to an exhaust gas sampling device.

  BACKGROUND ART An exhaust gas sampling device for measuring the concentration of ammonia contained in exhaust gas is known. 2. Description of the Related Art Conventionally, ammonia has been collected by a collection pipe arranged in a flue. However, there is a problem that the accuracy of the measured value of the ammonia concentration is reduced because the ammonia adheres to the inside of the sampling pipe. On the other hand, Patent Literature 1 describes an exhaust gas collecting instrument in which ammonia adhered to the inside of a collection tube is washed away with washing water, and the used washing water is included in a sample to be measured. According to the technique of Patent Literature 1, measurement accuracy of the concentration of ammonia contained in exhaust gas can be improved.

JP 2012-93156 A

  By the way, when ammonia is sampled using washing water as in the technique described in Patent Document 1, although the sampling accuracy of ammonia is improved, there is a limit to the improvement of the sampling efficiency because the washing step is required. Was.

  The present invention has been made in view of the above, and an object of the present invention is to provide an exhaust gas collecting apparatus capable of improving the collecting accuracy of ammonia and improving the collecting efficiency.

  In order to solve the above-described problems and achieve the object, an exhaust gas collecting apparatus according to the present invention has an end disposed inside an exhaust gas passage through which exhaust gas flows, and another end disposed outside the exhaust gas passage. A collecting pipe capable of collecting exhaust gas from an opening disposed inside the exhaust gas flow path, one end being disposed inside the exhaust gas flow path, and the other end being disposed outside the exhaust gas flow path. An outer pipe surrounding at least a part of the collection pipe and containing a heat medium in contact with the collection pipe, an absorbent for capturing ammonia, and connected to the collection pipe outside the exhaust gas flow path. And a case that covers the absorbing material.

  Thereby, the heat of the exhaust gas is transmitted to the collection pipe via the heat medium, and the collection pipe is heated. Further, since the other end of the outer pipe is located outside the exhaust gas flow path, the portion of the sampling pipe located outside the exhaust gas flow path is also maintained at a temperature close to the temperature inside the exhaust gas flow path. For this reason, when the exhaust gas passes through the inside of the collection pipe, the ammonia in the exhaust gas hardly adheres to the inner wall of the collection pipe. For this reason, an error due to the adhesion of the sampling tube to the inner wall is suppressed. Then, the ammonia in the exhaust gas passing through the collection pipe flows into the cartridge. Since the cartridge is located outside the exhaust gas channel, the exhaust gas flowing into the cartridge is cooled. This makes it difficult for the ammonia in the exhaust gas to maintain a gaseous state, and is thus captured by the absorbent. For this reason, the exhaust gas collecting apparatus can accurately collect ammonia without performing the cleaning step required in the prior art. Therefore, the exhaust gas collecting apparatus can improve the collection accuracy of ammonia and the collection efficiency.

  As a desirable mode of the present invention, it is preferred that the case is provided with a radiation fin which promotes heat transfer from the case to the outside.

  This suppresses a rise in the temperature of the cartridge due to the heat of the exhaust gas. For this reason, the exhaust gas sampling apparatus can increase the flow rate of the exhaust gas passing through the cartridge while maintaining the temperature of the cartridge at a predetermined value or less. Therefore, the exhaust gas collection device can further improve the collection efficiency.

  As a desirable mode of the present invention, it is preferred that the case is provided with a main part which contains the absorption material, and a connecting part provided at one end of the main part and which can be inserted in the sampling tube.

  This facilitates positioning of the cartridge with respect to the collection tube. For this reason, attachment of the cartridge to the collection tube becomes easy.

  As a desirable mode of the present invention, the outer tube includes caps at both ends for sealing a gap between the outer tube and the collection tube, and a tip of the connection portion is more than the cap located outside the exhaust gas flow path. It is preferably located on the exhaust gas channel side.

  The portion of the collection tube that contacts the cap has a lower temperature than the portion of the collection tube that contacts the heating medium. For this reason, the possibility that ammonia adheres to the portion of the collection tube that contacts the cap is higher than that of the collection tube that contacts the heat medium. On the other hand, the exhaust gas can flow into the cartridge before reaching the position corresponding to the cap because the tip of the first connecting portion is located closer to the exhaust gas flow path than the cap. Therefore, the exhaust gas collecting apparatus can further improve the collecting accuracy of ammonia.

  As a desirable mode of the present invention, it is preferred that the outer pipe is provided with a heating fin in the exhaust gas flow passage for promoting heat transfer from the exhaust gas in the exhaust gas flow passage to the heating medium.

  Thereby, the temperature of the heat medium is easily maintained at a temperature close to the temperature inside the exhaust gas channel. Therefore, the possibility that ammonia adheres to the inner wall of the collection pipe when the exhaust gas passes through the inside of the collection pipe is reduced. Therefore, the exhaust gas collecting apparatus can further improve the collecting accuracy of ammonia.

  Advantageous Effects of Invention According to the present invention, it is possible to provide an exhaust gas collecting apparatus capable of improving the collecting accuracy of ammonia and improving the collecting efficiency.

FIG. 1 is a schematic diagram illustrating an exhaust gas sampling device according to the present embodiment. FIG. 2 is a cross-sectional view illustrating the periphery of the collection tube according to the present embodiment. FIG. 3 is a flowchart illustrating a sampling method using the exhaust gas sampling device according to the present embodiment.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited by the following embodiments for carrying out the invention (hereinafter, referred to as embodiments). The components in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those that are in the so-called equivalent range. Furthermore, components disclosed in the following embodiments can be appropriately combined.

(Embodiment)
FIG. 1 is a schematic diagram illustrating an exhaust gas sampling device according to the present embodiment. FIG. 2 is a cross-sectional view illustrating the periphery of the collection tube according to the present embodiment. The exhaust gas sampling device 1 is a device that samples the exhaust gas 90 from an exhaust gas channel 9 through which the exhaust gas 90 flows, for example, to measure the concentration of ammonia contained in the exhaust gas 90 of a thermal power plant or the like.

A denitration device is used to remove nitrogen oxides (NOx) contained in the exhaust gas 90 flowing inside the exhaust gas passage 9. The denitration device decomposes nitrogen oxides (NOx) into nitrogen (N ₂ ) and water (H ₂ O) by injecting ammonia (NH ₃ ) into the exhaust gas and bringing it into contact with the catalyst.

Some of the ammonia injected into the exhaust gas 90 by the denitration device may pass through the catalyst without reacting with the nitrogen oxide. Ammonia (unreacted ammonia) contained in the exhaust gas 90 that has passed through the denitration device reacts with sulfur oxide (SOx) contained in the exhaust gas 90 to produce ammonium hydrogen sulfate (NH ₄ HSO ₄ ). The generated acidic ammonium sulfate may block an air heater disposed downstream of the denitration device. Therefore, in order to operate the thermal power plant smoothly, it is necessary to grasp the ammonia concentration contained in the exhaust gas 90 that has passed through the denitration device. An exhaust gas collecting device 1 is provided in the exhaust gas channel 9 to collect ammonia from the exhaust gas channel 9.

  As shown in FIG. 1, the exhaust gas sampling apparatus 1 includes a sampling pipe 4, an outer pipe 3, a cartridge 2, a flow meter 11, a pump 12, a first connection pipe 17, a second connection pipe 18, A control device 13, a first thermometer 14, and a second thermometer 15 are provided.

  The collection pipe 4 is a hollow member for collecting the exhaust gas 90. When the exhaust gas 90 is collected, the exhaust gas 90 passes through the inside of the collection pipe 4. One end of the collection pipe 4 is disposed inside the exhaust gas flow path 9, and the other end of the collection pipe 4 is disposed outside the exhaust gas flow path 9. That is, the sampling pipe 4 penetrates the outer wall 91 of the exhaust gas channel 9. The collection tube 4 has an opening 41 at one end. The opening 41 opens toward the upstream side of the flow of the exhaust gas 90.

  As shown in FIG. 2, the outer tube 3 is a hollow member surrounding the sampling tube 4. For example, the entire length of the outer tube 3 is shorter than the entire length of the sampling tube 4. For this reason, the outer tube 3 surrounds a part of the sampling tube 4. One end of the outer tube 3 is disposed inside the exhaust gas channel 9, and the other end of the outer tube 3 is disposed outside the exhaust gas channel 9. That is, the outer pipe 3 penetrates the outer wall 91 of the exhaust gas passage 9. More specifically, one end of the outer tube 3 is arranged at a position closer to the outer wall 91 than the opening 41 of the collection tube 4. The other end of the outer tube 3 is arranged at the same position as the other end of the sampling tube 4.

  The outer tube 3 includes a main body 30, a cap 31, and a heating fin 33. The main body 30 is, for example, a cylindrical member, and incorporates the heat medium 35. The heat medium 35 is, for example, heat medium oil having a boiling point of 300 ° C. or more, and is in contact with the sampling pipe 4. That is, the sampling pipe 4 is immersed in the heat medium 35. The caps 31 are arranged at both ends of the main body 30, and seal the gap between the main body 30 and the collection tube 4. The cap 31 prevents the heat medium 35 from leaking outside. The heating fin 33 is a member for promoting heat transfer from the exhaust gas 90 to the heat medium 35. A plurality of heating fins 33 are arranged on the outer wall of the main body 30 located inside the exhaust gas passage 9 along the longitudinal direction of the outer tube 3. For example, the shape of the heating fin 33 as viewed from the longitudinal direction of the outer tube 3 is annular. The heating fin 33 is formed of a metal having a high thermal conductivity such as an aluminum alloy.

  The temperature of the exhaust gas 90 is, for example, about 300 ° C. Since the main body 30 contacts the exhaust gas 90, the heat of the exhaust gas 90 is transmitted to the heat medium 35 via the main body 30. Further, since the heating fins 33 are also in contact with the exhaust gas 90, the heat of the exhaust gas 90 is transmitted to the heat medium 35 via the heating fins 33 and the main body 30. When the heat medium 35 is heated by the heat of the exhaust gas 90, the temperature of the heat medium 35 becomes substantially equal to the temperature of the exhaust gas 90. Since the heat medium 35 is in contact with the collection pipe 4, the heat of the heat medium 35 is transmitted to the inside of the collection pipe 4. Thus, the temperature inside the sampling pipe 4 becomes substantially equal to the temperature of the heat medium 35. That is, the temperature inside the collection tube 4 is maintained at about 300 ° C. Thereby, when collecting the exhaust gas 90, the adhesion of the ammonia compound to the inner wall of the collection pipe 4 is suppressed.

  The cartridge 2 is a device for capturing ammonia. As shown in FIG. 2, the cartridge 2 is connected to the sampling pipe 4 outside the exhaust gas channel 9. The cartridge 2 is detachably attached to the collection tube 4. The cartridge 2 includes an absorbing material 22 that captures ammonia, a case 21 that covers the absorbing material 22, a first seal 23, and a second seal 24.

The absorbent 22 is solid and is filled inside the case 21. For example, when the sulfur trioxide (SO ₃ ) concentration of the exhaust gas 90 is higher than the ammonia concentration in the preliminary measurement, glass wool (silica wool) is used as the absorbent 22. On the other hand, when the sulfur trioxide concentration of the exhaust gas 90 is smaller than the ammonia concentration in the preliminary measurement, a filler chemically modified with sulfonic acid is used as the absorbent 22.

  The case 21 includes a main body 210, a first connecting part 211, a second connecting part 212, and a radiation fin 213. The main body 210 is a member that contains and positions the absorbing material 22, and is, for example, a substantially cylindrical hollow member. The first connecting portion 211 is a cylindrical member protruding from one end of the main body 210. The outer periphery of the first connecting portion 211 is smaller than the inner periphery of the collection tube 4. The first connecting portion 211 is inserted into the collection pipe 4 from an end of the collection pipe 4 located outside the exhaust gas flow path 9. For example, the end of the first connecting portion 211 is located closer to the exhaust gas flow path 9 than the cap 31 is. The first connecting portion 211 can guide the exhaust gas 90 in the sampling pipe 4 to the main body 210. The second connecting portion 212 is a cylindrical member protruding from the other end of the main body 210. The outer circumference of the second connection part 212 is smaller than the inner circumference of the first connection pipe 17. The second connection part 212 is inserted into the first connection pipe 17. The second connection part 212 can guide the gas in the main body part 210 to the first connection pipe 17. The radiation fins 213 are members for promoting heat transfer from the case 21 to the outside. A plurality of heat radiation fins 213 are arranged on the outer wall of the main body 210 along the longitudinal direction of the sampling tube 4. For example, the shape of the radiation fin 213 viewed from the longitudinal direction of the sampling tube 4 is annular. The radiation fins 213 are formed of a metal having a high thermal conductivity such as an aluminum alloy.

  The first seal 23 is a member for sealing a gap between the cartridge 2 and the collection tube 4. The first seal 23 is, for example, an O-ring formed of synthetic rubber or the like. As shown in FIG. 2, the first seal 23 is positioned by being sandwiched between the collection tube 4 and the main body 210. Since the first seal 23 seals the gap between the collection pipe 4 and the main body 210, the invasion of air outside the exhaust gas passage 9 into the collection pipe 4 is suppressed.

  The second seal 24 is a member for sealing a gap between the cartridge 2 and the first connection pipe 17. The second seal 24 is, for example, an O-ring formed of synthetic rubber or the like. As shown in FIG. 2, the second seal 24 is positioned by being sandwiched between the first connection pipe 17 and the main body 210. Since the gap between the first connection pipe 17 and the main body 210 is sealed by the second seal 24, entry of air outside the exhaust gas passage 9 into the first connection pipe 17 is suppressed.

  As described above, since the temperature of the exhaust gas 90 inside the collection pipe 4 is about 300 ° C., heat is transmitted from the collection pipe 4 to the cartridge 2. On the other hand, the cartridge 2 is disposed outside the exhaust gas passage 9 at room temperature. For this reason, the heat transmitted from the collection tube 4 to the cartridge 2 is transmitted to the outside via the main body 210. Further, since the radiation fins 213 are exposed to the outside, the heat of the cartridge 2 is transmitted to the outside via the main body 210 and the radiation fins 213. Thereby, the exhaust gas 90 is cooled when flowing into the cartridge 2. For example, the exhaust gas 90 is cooled to 100 ° C. or lower before passing through the absorber 22. When the exhaust gas 90 is cooled to 100 ° C. or lower, it becomes difficult for ammonia to maintain a gaseous state. Therefore, the ammonia in the exhaust gas 90 is captured by the absorber 22.

  When the sulfur trioxide concentration of the exhaust gas 90 is higher than the ammonia concentration, when the exhaust gas 90 is cooled in the absorbent 22, acidic ammonium sulfate is generated in the absorbent 22 which is glass wool. That is, the ammonia in the exhaust gas 90 is captured by the absorbent 22 as acidic ammonium sulfate. On the other hand, when the sulfur trioxide concentration of the exhaust gas 90 is smaller than the ammonia concentration, when the exhaust gas 90 is cooled in the absorbent 22, the ammonia is captured by the absorbent 22 which is a filler modified with sulfonic acid.

  The flow meter 11 is a device for measuring the flow rate of gas passing through the cartridge 2. The flow meter 11 is, for example, a flow meter capable of measuring a mass flow rate and controlling the flow rate. That is, the flow meter 11 is a mass flow controller. As shown in FIG. 1, the flow meter 11 is connected to the cartridge 2 via a first connection pipe 17. The gas that has passed through the cartridge 2 flows into the flow meter 11 via the first connection pipe 17.

  The pump 12 is a device for guiding the exhaust gas 90 to the cartridge 2. As shown in FIG. 1, the pump 12 is connected to the flow meter 11 via a second connection pipe 18, and the inside of the second connection pipe 18 can be set to a negative pressure. When the pump 12 is operated, the inside of the second connection pipe 18, the first connection pipe 17, the cartridge 2 and the collection pipe 4 has a negative pressure, so that the exhaust gas 90 flows into the collection pipe 4 from the opening 41. The exhaust gas 90 is discharged from the pump 12 after passing through the sampling pipe 4, the cartridge 2, and the flow meter 11 in this order.

  The control device 13 is a computer such as a personal computer (PC), and has an input interface, an output interface, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and an internal storage. And an apparatus. The input interface, the output interface, the CPU, the ROM, the RAM, and the internal storage device are connected by an internal bus. The control device 13 can change the output signal according to the change of the input signal. The control device 13 is electrically connected to the first thermometer 14 and the second thermometer 15 and can receive an input signal from the first thermometer 14 and the second thermometer 15. Further, the control device 13 is electrically connected to the flow meter 11 and the pump 12, and can output an output signal to the flow meter 11 and the pump 12, and can receive an input signal from the flow meter 11.

  The first thermometer 14 is a device for measuring the temperature inside the sampling pipe 4. The first thermometer 14 has a probe 141 and a temperature measuring unit 142. For example, the probe 141 passes through the outer tube 3 and the collection tube 4. The temperature measuring unit 142 is arranged at the tip of the probe 141 and measures the temperature inside the sampling tube 4. The first thermometer 14 outputs the measurement result of the temperature measuring unit 142 to the control device 13 as a signal at regular intervals.

  The second thermometer 15 is a device for measuring the temperature inside the first connection pipe 17. That is, the second thermometer 15 is a device for measuring the temperature of the gas that has passed through the cartridge 2. The second thermometer 15 has a probe 151 and a temperature measuring unit 152. For example, the probe 151 passes through the first connection pipe 17. The temperature measuring unit 152 is arranged at the tip of the probe 151 and measures the temperature inside the first connection pipe 17. The second thermometer 15 outputs a measurement result of the temperature measuring unit 152 to the control device 13 at predetermined time intervals as a signal.

  The control device 13 operates the pump 12 according to an input signal from the first thermometer 14. Specifically, the control device 13 operates the pump 12 when the measurement result of the first thermometer 14 becomes, for example, 300 ° C. or more. Further, the control device 13 stops the pump 12 according to an input signal from the flow meter 11. Specifically, the control device 13 integrates the flow rate in the flow meter 11, and stops the pump 12 when the integrated value of the flow rate becomes equal to or more than a predetermined value. Further, the control device 13 issues a signal to the flow meter 11 according to an input signal from the second thermometer 15. The flow meter 11 can adjust the flow rate of the gas passing therethrough in accordance with an input signal from the control device 13. Specifically, when the measurement result of the second thermometer 15 becomes, for example, 100 ° C. or more, the control device 13 sends a signal to the flow meter 11 to reduce the flow rate of the gas passing through the flow meter 11.

  FIG. 3 is a flowchart illustrating a sampling method using the exhaust gas sampling device according to the present embodiment. As shown in FIG. 3, when collecting the exhaust gas 90 using the exhaust gas collecting apparatus 1 according to the present embodiment, the cartridge 2 is connected to the collecting pipe 4 (Step S1). FIGS. 1 and 2 show a state after the cartridge 2 is connected to the collection tube 4.

  Next, the control device 13 determines whether the temperature inside the sampling pipe 4 is equal to or higher than a predetermined value. That is, the control device 13 compares the measured value of the first thermometer 14 with a predetermined value. For example, the predetermined value is 300 ° C. When the measured value of the first thermometer 14 is less than the predetermined value (No at Step S2), the control device 13 repeats the comparison between the measured value of the first thermometer 14 and the predetermined value.

  When the measured value of the first thermometer 14 is equal to or more than the predetermined value (Step S2, Yes), the control device 13 outputs a signal to the pump 12 to start the suction of the cartridge 2 by the pump 12 (Step S3). Thus, the exhaust gas 90 passes through the inside of the collection pipe 4 in a state where the temperature inside the collection pipe 4 is equal to or higher than the predetermined value of 300 ° C. Therefore, the ammonia in the exhaust gas 90 hardly adheres to the inner wall of the collection pipe 4, so that the ammonia in the exhaust gas 90 flows into the cartridge 2 through the collection pipe 4.

  Next, the control device 13 determines whether the temperature of the gas flowing out of the cartridge 2 is equal to or lower than a predetermined value. That is, the control device 13 compares the measured value of the second thermometer 15 with the predetermined value. For example, the predetermined value is 100 ° C. When the measured value of the second thermometer 15 is equal to or larger than the predetermined value (Step S4, No), the control device 13 outputs a signal to the flow meter 11, and reduces the flow rate in the flow meter 11, that is, the flow rate in the cartridge 2 ( Step S41). As a result, the temperature rise of the cartridge 2 is suppressed, and the measured value of the second thermometer 15 decreases. Thereafter, the control device 13 performs step S4 again.

  When the measurement value of the second thermometer 15 is equal to or less than the predetermined value (Step S4, Yes), the control device 13 compares the integrated value of the flow rate of the gas passing through the flow meter 11 (the integrated flow rate) with the predetermined value. . The predetermined value is set, for example, according to the capacity of the absorbent 22. When the integrated flow rate is less than the predetermined value (Step S5, No), the control device 13 performs Step S4 again. When the temperature of the gas flowing out of the cartridge 2 is equal to or lower than the predetermined value of 100 ° C., the cartridge 2 is cooled to a temperature close to 100 ° C. Therefore, the ammonia in the exhaust gas 90 flowing into the cartridge 2 is captured by the absorbent 22.

  If the integrated flow rate is equal to or more than the predetermined value (step S5, Yes), a signal is output to the pump 12, and the suction of the cartridge 2 by the pump 12 is stopped (step S6). Thus, the flow of the exhaust gas 90 into the cartridge 2 is stopped.

  Next, the cartridge 2 is removed from the collection tube 4 (Step S7). When sampling of the exhaust gas 90 is performed continuously, a new cartridge 2 is connected to the sampling pipe 4. On the other hand, when the sampling of the exhaust gas 90 is not performed continuously, the end of the sampling pipe 4 is sealed by, for example, a lid. Thereby, leakage of the exhaust gas 90 is prevented.

  The amount of ammonia collected by the absorbent 22 of the cartridge 2 through the above-described collecting method is measured by various methods. For example, the cartridge 2 after collecting the ammonia is immersed in a boric acid solution. As a result, the ammonia captured by the absorbent 22 dissolves into the boric acid solution. Then, the amount of ammonia captured by the absorber 22 is measured by, for example, indophenol blue absorptiometry. After that, the ammonia concentration in the exhaust gas 90 is calculated based on the amount of ammonia captured by the absorbent 22 and the integrated flow rate of the flow meter 11.

  Further, the amount of ammonia captured by the absorbent 22 can be measured by gasifying the ammonia captured by the absorbent 22. For example, the amount of ammonia captured by the absorbent 22 is measured by a method similar to the head space method of gas chromatography. In this case, the cartridge 2 after collecting the ammonia is heated to, for example, about 550 ° C. Then, by analyzing the ammonia in the gas generated by the heating, the amount of ammonia captured by the absorber 22 is measured. After that, the ammonia concentration in the exhaust gas 90 is calculated based on the amount of ammonia captured by the absorbent 22 and the integrated flow rate of the flow meter 11.

  Note that the predetermined value in step S2 does not necessarily need to be 300 ° C., and may be appropriately set, for example, in a range of about 250 ° C. or more. Further, the predetermined value in step S4 does not necessarily have to be 100 ° C., and may be set appropriately, for example, in a range of about 150 ° C. or less. For example, if the temperature of the cartridge 2 is equal to or lower than 150 ° C., it is difficult to maintain the gaseous state of ammonia, so that the ammonia is captured by the absorbent 22.

  In addition, the flow meter 11 does not necessarily need to be arranged on the upstream side of the pump 12 as shown in FIG. 1, and may be arranged on the downstream side of the pump 12. That is, the cartridge 2 and the pump 12 may be connected by the first connection pipe 17, and the pump 12 and the flowmeter 11 may be connected by the second connection pipe 18.

  In addition, the first thermometer 14 does not necessarily need to measure the temperature inside the sampling pipe 4, and may measure, for example, the temperature of the heat medium 35 or the temperature of the outer pipe 3. . Further, the second thermometer 15 does not necessarily need to measure the temperature of the gas that has passed through the cartridge 2, and may measure, for example, the temperature of the main body 210 of the cartridge 2. Further, the control device 13, the first thermometer 14, and the second thermometer 15 are not necessarily required.

  Note that the cartridge 2 does not necessarily have to include the first seal 23 and the second seal 24. When the first seal 23 is not provided, for example, even if the outer circumference of the first connection part 211 formed of an elastic body or the like is larger than the inner circumference of the collection pipe 4, the first connection part 211 is press-fitted into the collection pipe 4. Good. Thereby, since the first connecting portion 211 is in close contact with the collection pipe 4, entry of air outside the exhaust gas passage 9 into the collection pipe 4 is suppressed. When the second seal 24 is not provided, for example, the outer circumference of the second connection part 212 formed of an elastic body or the like is larger than the inner circumference of the first connection pipe 17, and the second connection part 212 is May be press-fitted. Thereby, since the second connection portion 212 is in close contact with the first connection pipe 17, the invasion of air outside the exhaust gas flow path 9 into the first connection pipe 17 is suppressed.

  Note that the case 21 of the cartridge 2 does not necessarily have to include the first connection portion 211, the second connection portion 212, and the heat radiation fins 213. The case 21 may have at least an opening for guiding the exhaust gas 90 that has passed through the sampling pipe 4 to the absorbent 22.

  As described above, the exhaust gas sampling apparatus 1 includes the sampling pipe 4, the outer pipe 3, and the cartridge 2. The sampling pipe 4 has one end disposed inside the exhaust gas passage 9 through which the exhaust gas 90 flows, and the other end disposed outside the exhaust gas passage 9, and has an opening 41 disposed inside the exhaust gas passage 9. From the exhaust gas 90. The outer pipe 3 has one end disposed inside the exhaust gas flow path 9 and the other end disposed outside the exhaust gas flow path 9, and surrounds at least a part of the collection pipe 4 and contacts the heat medium 35 in contact with the collection pipe 4. Built-in. The cartridge 2 has an absorbent 22 for capturing ammonia, and a case 21 connected to the sampling pipe 4 outside the exhaust gas passage 9 and covering the absorbent 22.

  Thereby, the heat of the exhaust gas 90 is transmitted to the collection pipe 4 via the heat medium 35, and the collection pipe 4 is heated. Further, since the other end of the outer pipe 3 is located outside the exhaust gas flow path 9, the portion of the sampling pipe 4 located outside the exhaust gas flow path 9 has a temperature close to the temperature inside the exhaust gas flow path 9. Will be kept. Therefore, when the exhaust gas 90 passes through the inside of the collection pipe 4, the ammonia in the exhaust gas 90 is less likely to adhere to the inner wall of the collection pipe 4. For this reason, an error due to the adhesion of the sampling tube 4 to the inner wall is suppressed. Then, the ammonia in the exhaust gas 90 that has passed through the collection pipe 4 flows into the cartridge 2. Since the cartridge 2 is located outside the exhaust gas passage 9, the exhaust gas 90 flowing into the cartridge 2 is cooled. This makes it difficult for the ammonia in the exhaust gas 90 to maintain a gaseous state, so that the ammonia is captured by the absorber 22. For this reason, the exhaust gas sampling apparatus 1 can sample ammonia with high accuracy without performing the cleaning step required in the prior art. Therefore, the exhaust gas collecting apparatus 1 can improve the collection accuracy of ammonia and the collection efficiency.

  Further, in the exhaust gas sampling apparatus 1, the case 21 includes a radiation fin 213 for promoting heat transfer from the case 21 to the outside.

  Thereby, the temperature rise of the cartridge 2 due to the heat of the exhaust gas 90 is suppressed. For this reason, the exhaust gas sampling apparatus 1 can increase the flow rate of the exhaust gas 90 passing through the cartridge 2 while maintaining the temperature of the cartridge 2 at a predetermined value or less. Therefore, the exhaust gas sampling device 1 can further improve the sampling efficiency.

  In the exhaust gas collecting apparatus 1, the case 21 includes a main body 210 containing the absorbent 22 and a connecting part (first connecting part 211) provided at one end of the main body 210 and capable of being inserted into the collecting pipe 4. Prepare.

  Thereby, the positioning of the cartridge 2 with respect to the sampling tube 4 is facilitated. For this reason, attachment of the cartridge 2 to the collection tube 4 becomes easy.

  Further, in the exhaust gas collecting apparatus 1, the outer pipe 3 has caps 31 at both ends for sealing a gap between the outer pipe 3 and the collecting pipe 4. The distal end of the connecting portion (first connecting portion 211) is located closer to the exhaust gas flow channel 9 than the cap 31 located outside the exhaust gas flow channel 9.

  The temperature of the portion of the collection tube 4 that is in contact with the cap 31 is lower than the portion of the collection tube 4 that is in contact with the heat medium 35. Therefore, the possibility that ammonia adheres to the portion of the collection tube 4 that is in contact with the cap 31 is higher than the portion of the collection tube 4 that is in contact with the heat medium 35. On the other hand, since the end of the first connecting portion 211 is located closer to the exhaust gas passage 9 than the cap 31, the exhaust gas 90 can flow into the cartridge 2 before reaching the position corresponding to the cap 31. it can. Therefore, the exhaust gas sampling apparatus 1 can further improve the sampling accuracy of ammonia.

  Further, in the exhaust gas sampling device 1, the outer pipe 3 includes a heating fin 33 inside the exhaust gas channel 9 for promoting heat transfer from the exhaust gas 90 inside the exhaust gas channel 9 to the heat medium 35.

  Thereby, the temperature of the heat medium 35 is easily maintained at a temperature close to the temperature inside the exhaust gas passage 9. Therefore, the possibility that ammonia adheres to the inner wall of the collection pipe 4 when the exhaust gas 90 passes through the inside of the collection pipe 4 is reduced. Therefore, the exhaust gas sampling apparatus 1 can further improve the sampling accuracy of ammonia.

DESCRIPTION OF SYMBOLS 1 Exhaust gas sampling apparatus 11 Flow meter 12 Pump 13 Controller 14 First thermometer 141 Probe 142 Temperature measuring unit 15 Second thermometer 151 Probe 152 Temperature measuring unit 17 First connection pipe 18 Second connection pipe 2 Cartridge 21 Case 210 Main body Part 211 First connecting part 212 Second connecting part 213 Radiation fin 22 Absorbent material 23 First seal 24 Second seal 3 Outer tube 30 Main body 31 Cap 33 Heating fin 35 Heat medium 4 Sampling pipe 41 Opening 9 Exhaust gas flow path 90 Exhaust gas 91 outer wall

Claims (4)

One end is disposed inside an exhaust gas flow path through which the exhaust gas flows, and the other end is disposed outside the exhaust gas flow path, so that exhaust gas can be collected from an opening disposed inside the exhaust gas flow path. Tubes and
One end is disposed inside the exhaust gas flow path and the other end is disposed outside the exhaust gas flow path, surrounds at least a part of the collection pipe, and includes an outer pipe that contains a heat medium that is in contact with the collection pipe. ,
A cartridge having an absorbing material for capturing ammonia, and a case connected to the sampling pipe outside the exhaust gas flow path and covering the absorbing material,
With
Wherein the case, the exhaust gas sampling device Ru provided with radiation fins to facilitate heat transfer to the outside from the case. The exhaust gas collecting apparatus according to claim 1, wherein the case includes a main body that contains the absorbing material, and a connecting part that is provided at one end of the main body and that can be inserted into the collecting pipe. The outer tube has caps at both ends for sealing a gap between the outer tube and the collection tube,
The exhaust gas sampling device according to claim 2 , wherein a tip of the connection portion is located closer to the exhaust gas flow path than the cap located outside the exhaust gas flow path. The outer tube, the inside of the exhaust gas flow path, from the exhaust gas inside the exhaust gas channel according to any one of claims 1 to 3, comprising a heating fins to facilitate heat transfer to the heat medium Exhaust gas sampling device.

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