JP2019066419A - Gas concentration measurement system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas concentration measuring system in which an optical axis of laser light is tilted in a direction perpendicular to a pipe axis of an exhaust pipe, and an exhaust pipe in which a gas concentration measuring system is installed due to a change in outside temperature is a pipe. Provided is a gas concentration measuring system in which the optical axis of the emitted laser light of the light emitter and the light receiving axis of the light receiving element of the light receiver do not deviate even if the light is expanded or contracted in the axial direction. A laser gas concentration measuring device, a first frame, a second frame, a first side tube for passing laser light, and a second side tube for passing laser light are provided, and the laser light is used. The light emitter is installed in the first frame and the receiver of the laser gas concentration measuring device is set in the second frame so that the optical axis is tilted in a direction perpendicular to the tube axis of the exhaust pipe. The light emitter is connected to the other end side of the first side tube for passing laser light via a cylindrical flexible coupling portion, and the light receiver is connected to the other end side of the laser light passing first side tube via a cylindrical flexible coupling portion. The gas concentration measuring system is characterized in that it is connected to the other end side of the second side tube for passing laser light. [Selection diagram] Fig. 1

Description

  The present invention is installed in an exhaust pipe of exhaust gas discharged from various manufacturing facilities and processing facilities, and the gas to be measured in the exhaust gas flowing in the exhaust pipe, for example, hydrogen chloride, carbon monoxide, carbon dioxide, sulfide A gas concentration measurement system for measuring the concentration of hydrogen, oxygen, etc. using a laser type gas concentration measurement apparatus, and relates to a gas concentration measurement system for measuring the concentration of a measurement target gas in exhaust gas having a low concentration of measurement target gas .

  Titanium tetrachloride is produced by chlorinating ore containing titanium oxide with chlorine gas. And, in the production of titanium tetrachloride, although the amount is small, hydrogen chloride is compounded, so the exhaust gas of the titanium tetrachloride production facility contains a trace amount of hydrogen chloride gas.

  Since hydrogen chloride gas is a harmful gas, emission restrictions are imposed on the exhaust gas emitted from the titanium tetrachloride manufacturing facility to the environment, and the restriction value is becoming lower year by year. For example, in Kanagawa Prefecture, the concentration of hydrogen chloride gas in exhaust gas is regulated to 5 ppm or less by the prefectural regulations. Therefore, it is necessary to continuously measure the hydrogen chloride gas concentration in the exhaust gas.

  As a method of measuring the concentration of hydrogen chloride gas in exhaust gas, conventionally, the method of measuring the concentration of hydrogen chloride gas in the exhaust gas from the waste incineration facility using a laser type gas concentration measuring device in the waste incineration facility It has been known.

  For example, as disclosed in Patent Document 1, this laser type gas concentration measuring apparatus utilizes the fact that each gas molecule or atom has its own light absorption spectrum, and the light absorption of the gas to be measured. A laser light source emits a laser light having the same emission wavelength band as the spectrum, and the laser light is irradiated to the measurement target space including the measurement target gas, and the laser light from the measurement target gas when the laser light passes through the measurement target space It is an apparatus which measures the absorption amount of light and calculates and calculates | requires measurement object gas concentration from the absorption amount of the laser beam.

  FIG. 11 shows a laser type gas concentration measurement system for measuring the concentration of the gas to be measured in the exhaust gas installed in the flue for discharging the exhaust gas from the refuse incineration facility. In FIG. 11, in the gas concentration measurement system 40, the flange member 44 for light emitter installation and the flange member 54 for light receiver installation are fitted and installed in the holes 48 and 49 for laser light transmission formed in the flue 52, The mounting flange portion 46 of the light emitter 41 is attached to the light emitter mounting flange member 44, whereby the light emitter 41 is installed in the flue 52, and the mounting flange of the light receiver 51 is mounted on the light receiver mounting flange member 54. The light receiver 51 is installed in the flue 52 by attaching the portion 56. At this time, the light emitter 41 and the light receiver 51 are installed such that the optical axis 47 of the laser light emitted from the light emitter 41 coincides with the light receiving axis of the light receiving element of the light receiver 51. The light emitter 41 and the light receiver 51 are electrically connected to a control unit (not shown). The control unit has operation means for obtaining the amount of absorption of the light absorption spectrum by the gas to be measured based on the light reception signal from the light receiving element, and calculating the gas concentration to be measured by various arithmetic processing.

  Then, in the gas concentration measurement system 40, laser light is emitted from the laser light source of the light emitter 41 toward the exhaust gas 53 in the flue 52, and the emitted laser light exhausts the exhaust gas 53 in the flue 52. The laser beam that has passed through and passed through the exhaust gas 53 in the flue 52 is received by the light receiving element of the light receiver 51. The amount of absorption of the light absorption spectrum by the gas to be measured is determined based on the light reception signal from the light receiving element, and the concentration of the gas to be measured is calculated from the amount of absorption.

  In this way, the gas concentration measurement system 40 is used to continuously measure the concentration of the gas to be measured in the exhaust gas 53 discharged through the flue 52.

JP 2001-159605 A

  The concentration of hydrogen chloride gas in the exhaust gas discharged from the waste incineration facility is about 40 ppm. If it is a density | concentration of this grade, in order to measure accurately using a laser type gas concentration measuring apparatus, the permeation | transmission distance when a laser beam permeate | transmits measurement object space (Hereafter, it describes as the measurement distance by a laser beam.) However, as long as it is about 500 mm, even if the optical axis 47 of the laser light is perpendicular to the axial direction of the flue 52, as in the gas concentration measurement system 40 shown in FIG. The measurement distance of the laser beam can be secured.

  On the other hand, if the concentration of the gas to be measured is very low, as in the case of exhaust gas emission regulations from titanium tetrachloride manufacturing facilities, in order to measure accurately, it is necessary to As compared with the case of measuring the hydrogen chloride gas concentration, it is necessary to increase the measurement distance by the laser beam. For example, in order to measure a hydrogen chloride gas concentration of about 5 ppm, it is necessary to secure a measurement distance by a laser beam of 1 m or more.

  However, in general, in many manufacturing facilities of titanium tetrachloride, since the pipe diameter of the exhaust pipe is less than 1 m, the optical axis of the laser beam of the laser type gas concentration measuring apparatus is in the direction of the pipe axis of the exhaust pipe. If the light emitter and the light receiver are placed vertically, it is not possible to secure a sufficient measurement distance by laser light.

  Therefore, in order to secure a sufficient measurement distance by the laser beam, the present inventors tilt the optical axis 67 of the laser beam with respect to the direction perpendicular to the tube axis of the exhaust pipe 30, as shown in FIG. As such, it was attempted to install the light emitter 61 and the light receiver 71.

  In the gas concentration measurement system 60 shown in FIG. 12, a laser for causing laser light to pass from the light emitter to the exhaust pipe such that the pipe axis is inclined to the exhaust pipe 30 with respect to the direction perpendicular to the pipe axis of the exhaust pipe 30 A light transmitting first side tube 63 is attached, and a light emitting device mounting flange member 64 is fitted to the other end of the laser light transmitting first light side tube 63, and the light emitting device mounting flange member 64 A mounting flange portion 61 of 61 is attached, and the light emitter 61 is installed, and from the exhaust pipe, the pipe axis is inclined with respect to the direction perpendicular to the pipe axis of the exhaust pipe 30, A laser beam passing second side tube 73 for passing the laser beam to the light receiver is attached, and the other end of the laser beam passing second side tube 73 is fitted with the light receiver installation flange member 74, Receiver installation flange member 7 , The mounting flange portion 76 of the light receiver 71 is attached, the light receiver 71 is installed.

  Here, vinyl chloride is generally used as the material of the exhaust pipe containing hydrogen chloride gas. Vinyl chloride is a material that is more easily expanded and contracted by heat than a metal material such as iron.

  Therefore, as shown in FIG. 13, when the daytime temperature rises, the exhaust pipe 30 extends in the axial direction 32 of the exhaust pipe. Then, the extension of the exhaust pipe 30 in the pipe axial direction 32 makes the distance between the first side pipe 63 and the second side pipe 73 in the pipe axial direction 32 longer than that at the time of installation. As a result, the optical axis 67 of the outgoing laser light of the light emitter 61 and the light receiving axis of the light receiving element of the light receiving device 71 are deviated, which causes a problem that normal measurement can not be performed.

  Also, when the air temperature becomes low, the exhaust pipe 30 contracts in the axial direction 32 of the exhaust pipe. Then, due to the contraction of the exhaust pipe 30 in the pipe axial direction 32, the distance between the laser light transmitting first side pipe 63 and the laser light transmitting second side pipe 73 in the pipe axial direction 32 becomes shorter than at the time of installation. As a result, the optical axis 67 of the outgoing laser light of the light emitter 61 and the light receiving axis of the light receiving element of the light receiving device 71 are shifted.

  Therefore, an object of the present invention is a gas concentration measurement system in which a light emitter and a light receiver are installed such that the optical axis of the laser light is inclined with respect to the direction perpendicular to the pipe axis of the exhaust pipe. Even if the exhaust pipe in which the gas concentration measurement system is installed changes due to change, the gas concentration measurement system in which the optical axis of the emitted laser light from the light emitter and the light receiving axis of the light receiving element of the light receiver do not easily shift It is to provide.

  In order to solve the present invention, as a result of intensive studies, the inventors fixed the light emitter to the first frame, fixed the light receiver to the second frame, and determined the positions of the light emitter and the light receiver. The first side tube for passing laser light and the second side for passing laser light which are attached to the exhaust pipe so as to be fixed so as not to move and to tilt the pipe axis with respect to the direction perpendicular to the pipe axis of the exhaust pipe. By connecting a light emitter and a light receiver to a pipe via a cylindrical flexible joint capable of expansion and contraction and bending deformation, even if the exhaust pipe expands and contracts in the axial direction of the pipe due to a change in the outside air temperature, It has been found that the optical axis of the outgoing laser light and the light receiving axis of the light receiving element of the light receiver can be hardly deviated, and the present invention has been completed.

That is, according to the present invention (1), the laser light containing the light absorption spectrum of the gas to be measured is transmitted through the exhaust pipe in which the exhaust gas containing the gas to be measured flows, and the laser light transmits the exhaust gas inside the exhaust pipe. A laser type gas concentration measuring device for determining the amount of absorption of the laser light by the gas to be measured at the time of measurement and determining the concentration of the gas to be measured in the exhaust gas from the amount of absorption of the laser light;
A light emitter of the laser type gas concentration measuring apparatus is installed, and a first frame for fixing the position of the light emitter,
A light receiver of the laser type gas concentration measuring apparatus is installed, and a second frame for fixing the position of the light receiver;
A laser through which the laser light passes from the light emitter to the exhaust pipe from the light source, and a laser whose one end is connected to the exhaust pipe so that the pipe axis is inclined with respect to the direction perpendicular to the pipe axis of the exhaust pipe A first side tube for light passage,
A laser through which the laser beam passes from the exhaust pipe to the light receiver on the inside, and a laser whose one end is connected to the exhaust pipe so that the pipe axis is inclined with respect to the direction perpendicular to the pipe axis of the exhaust pipe A second side pipe for light passage,
Have
A light emitter of the laser type gas concentration measuring apparatus is installed in the first frame so that the optical axis of the laser light is inclined with respect to a direction perpendicular to the tube axis of the exhaust pipe, and the laser type gas concentration measurement The receiver of the device is set to the second frame,
The light emitter is connected to the other end of the first side tube for passing laser light through a cylindrical flexible joint, and the light receiver is connected to the laser through a cylindrical flexible joint. Being connected to the other end of the second side pipe for light passage,
The present invention provides a gas concentration measurement system characterized by

  Further, the present invention (2) provides the gas concentration measurement system according to (1), wherein the gas to be measured is hydrogen chloride, carbon monoxide, carbon dioxide, hydrogen sulfide or oxygen. .

  Further, the present invention (3) provides the gas concentration measurement system according to (1), wherein the gas to be measured is hydrogen chloride, and the concentration of hydrogen chloride in the exhaust gas is 10 ppm or less. It is a thing.

  Further, the present invention (4) provides the gas concentration measurement system according to any one of (1) to (3) characterized in that the material of the exhaust pipe is polyethylene, polypropylene, carbon steel or stainless steel. is there.

  Further, the present invention (5) provides the gas concentration measurement system according to any one of (1) to (4), characterized in that the first frame and the second frame are connected at a connecting portion. It is.

  According to the present invention, it is a gas concentration measurement system in which a light emitter and a light receiver are installed such that the optical axis of the laser light is inclined with respect to the direction perpendicular to the pipe axis of the exhaust pipe. Provided is a gas concentration measurement system in which the optical axis of the emitted laser light of the light emitter and the light receiving axis of the light receiving element of the light receiver do not easily shift even if the exhaust pipe in which the gas concentration measuring system is installed extends and contracts in the tube axis direction. be able to.

It is a typical perspective view showing an example of a gas concentration measuring system of the present invention. It is the figure which looked at the gas concentration measurement system 10a shown in FIG. 1 from the top. It is the figure which looked at the gas concentration measurement system 10a shown in FIG. 1 from the side, and is the figure seen from A direction of FIG. It is the figure which looked at the gas concentration measurement system 10a shown in FIG. 1 from the side, and is the figure seen from B direction of FIG. It is the figure which looked at the gas concentration measurement system 10a shown in FIG. 1 from the upper direction, and is a figure which shows a mode when the exhaust pipe 30 is extended in the pipe axial direction. It is the figure which looked at gas concentration measurement system 10a shown in Drawing 1 from the top, and is a figure showing signs that exhaust pipe 30 contracted in the direction of a pipe axis. It is the figure which expanded the light receiver 11 vicinity in FIG. 2, and is the figure which piled up the back and front to which the exhaust pipe 30 is extended. It is a schematic diagram showing an embodiment of the gas concentration measurement system of the present invention. It is a schematic diagram showing an embodiment of the gas concentration measurement system of the present invention. It is a schematic diagram showing an embodiment of the gas concentration measurement system of the present invention. This is a gas concentration measurement system for measuring the concentration of the gas to be measured in the exhaust gas from the refuse incineration facility. It is a comparative example of the gas concentration measurement system which installs a light emitter and a light receiver so that an optic axis of a laser beam may incline to a direction perpendicular to a tube axis of an exhaust pipe. FIG. 13 is a diagram showing how the exhaust pipe extends in the axial direction of the pipe due to a change in the outside air temperature in the gas concentration measurement system in FIG. 12. 5 is a graph showing the results of Example 1; It is a graph which shows the result of comparative example 1.

In the gas concentration measurement system according to the present invention, the laser light containing the light absorption spectrum of the gas to be measured is transmitted through the exhaust pipe in which the exhaust gas containing the gas to be measured flows, and the laser light transmits the exhaust gas in the exhaust pipe. A laser type gas concentration measuring device for determining the amount of absorption of the laser light by the gas to be measured at the time of measurement and determining the concentration of the gas to be measured in the exhaust gas from the amount of absorption of the laser light;
A light emitter of the laser type gas concentration measuring apparatus is installed, and a first frame for fixing the position of the light emitter,
A light receiver of the laser type gas concentration measuring apparatus is installed, and a second frame for fixing the position of the light receiver;
A laser through which the laser light passes from the light emitter to the exhaust pipe from the light source, and a laser whose one end is connected to the exhaust pipe so that the pipe axis is inclined with respect to the direction perpendicular to the pipe axis of the exhaust pipe A first side tube for light passage,
A laser through which the laser beam passes from the exhaust pipe to the light receiver on the inside, and a laser whose one end is connected to the exhaust pipe so that the pipe axis is inclined with respect to the direction perpendicular to the pipe axis of the exhaust pipe A second side pipe for light passage,
Have
A light emitter of the laser type gas concentration measuring apparatus is installed in the first frame so that the optical axis of the laser light is inclined with respect to a direction perpendicular to the tube axis of the exhaust pipe, and the laser type gas concentration measurement The receiver of the device is set to the second frame,
The light emitter is connected to the other end of the first side tube for passing laser light through a cylindrical flexible joint, and the light receiver is connected to the laser through a cylindrical flexible joint. Being connected to the other end of the second side pipe for light passage,
A gas concentration measurement system characterized by

  The gas concentration measurement system of the present invention will be described with reference to FIGS. 1 to 7. FIG. 1 is a schematic perspective view showing an embodiment of the gas concentration measurement system of the present invention, and in FIG. 1 (B), a gas concentration measurement system 10a is shown by a solid line and an exhaust pipe 30 is shown by a dotted line. FIG. 2 is a top view of the gas concentration measurement system 10a shown in FIG. 3 is a view of the gas concentration measurement system 10a shown in FIG. 1 as viewed from the side, as viewed from the direction A of FIG. FIG. 4 is a view of the gas concentration measurement system 10a shown in FIG. 1 as viewed from the side, as viewed in the direction B in FIG. FIG. 5 is a top view of the gas concentration measurement system 10a shown in FIG. 1, and shows a state in which the exhaust pipe 30 extends in the axial direction of the pipe. FIG. 6 is a top view of the gas concentration measurement system 10a shown in FIG. 1, and shows a state in which the exhaust pipe 30 is contracted in the axial direction of the pipe. FIG. 7 is an enlarged view of the vicinity of the light receiver 11 in FIG. 2 and is a view in which an exhaust pipe 30 extends and is overlapped.

  The gas concentration measurement system 10a has a laser gas concentration measurement device. That is, the gas concentration measurement system 10a is a measurement system of gas concentration using a laser type gas concentration measurement device. The laser type gas concentration measuring apparatus used for the gas concentration measuring system 10a transmits the exhaust gas 31 in the exhaust pipe 30 and the light emitter 1 including the laser light source for emitting the laser light including the light absorption spectrum of the gas to be measured. It comprises a light receiver 11 having a light receiving element for receiving laser light, and a control unit (not shown) electrically connected to the light emitter 1 and the light receiver 11. The control unit includes an operation unit that calculates the gas concentration.

  In the gas concentration measurement system 10a, the light emitter 1 is installed, the first frame 2 for fixing the position of the light emitter 1 and the light receiver 11 are provided, and the second frame for fixing the position of the light receiver 11 And 12). The first frame 2 includes an outer frame portion 21 having a U-shape (a shape forming three sides of a rectangle), a light emitter lower fixed frame portion 22 for fixing the lower side of the light emitter 1, and the upper side of the light emitter 1. It comprises a light emitter upper fixed frame portion 23 to be fixed, a light emitter left fixed frame portion 24 to fix the left side of the light emitter 1, and a light emitter right fixed frame portion 25 to fix the right side of the light emitter 1. The second frame 12 includes a U-shaped outer frame portion, a light receiver lower fixed frame portion fixing the lower side of the light receiver 2, a light receiver upper fixed frame portion fixing the upper side of the light receiver 2, It comprises a light receiver left fixed frame portion for fixing the left side of the device 2 and a light receiver right fixed frame portion for fixing the right side of the light receiver 2. And since the light emitter 1 and the light receiver 11 are installed in the first frame 2 and the second frame 12 whose position does not shift or hardly shift even if the outside temperature changes, even if the outside temperature changes, or Even if the exhaust pipe 30 expands and contracts in the pipe axial direction 32 due to a change in the outside air temperature, the positions of the light emitter 1 and the light receiver 11 are fixed. In the gas concentration measurement system 10 a, the upper end of the outer frame portion of the first frame 2 and the upper end of the outer frame portion of the second frame 12 are connected by the connecting portion 9 a 1. The other upper end of the frame portion and the other upper end of the outer frame portion of the second frame 12 are connected by a connecting portion 9a2.

  In the gas concentration measurement system 10 a, the laser beam passing first side pipe 3 whose one end is connected to the exhaust pipe 30 and the exhaust pipe 30 so that the pipe axis is inclined to the direction 33 perpendicular to the pipe axis of the exhaust pipe 30. The laser light transmitting second side pipe 13 has one end connected to the exhaust pipe 30 so that the pipe axis is inclined with respect to the direction 33 perpendicular to the pipe axis. The first side tube 3 for laser beam passage is a member forming a passage path for passing the laser beam from the light emitter 1 to the exhaust tube 30 on the inside, and the second side tube 13 for laser beam passage is The inner side is a member for forming a passage path for passing the laser beam from the exhaust pipe 30 to the light receiver 11.

  In the gas concentration measurement system 10a, the light emitter 1 is installed on the first frame 2 so that the optical axis 7 of the laser light is inclined with respect to the direction 33 perpendicular to the tube axis 29 of the exhaust pipe 30, and the light receiver 11 is The second frame 12 is set. That is, the light emitter 1 is installed on the first frame 2 and the light receiver 11 is set on the second frame 12 so that the optical axis of the outgoing laser light of the light emitter 1 and the light receiving axis of the light receiver 12 do not shift. There is. In the gas concentration measurement system 10a, the laser light can pass through the inside of the exhaust pipe 30 in a direction inclined with respect to the direction 33 perpendicular to the tube axis of the exhaust pipe 30, so the laser light transmits the exhaust gas. The distance (measurement distance by laser light) can be increased.

  In the gas concentration measurement system 10 a, the light emitter installation flange member 4 is fitted to the other end of the laser light passing first side tube 3, and the light emitter installation flange member 4 and the mounting flange portion of the light emitter 1 6 are connected by a cylindrical flexible joint 5. As a result, the light emitter 1 is connected to the other end side of the first side tube 3 for laser beam passage via the cylindrical flexible joint 5. Further, in the gas concentration measurement system 10a, the light receiver installation flange member 14 is fitted to the other end of the laser light passing second side pipe 13, and the light receiver installation flange member 14 and the light receiver 11 are attached The flange portion 16 is connected by a cylindrical flexible connecting portion 15. As a result, the light receiver 11 is connected to the other end side of the laser light passing second side pipe 13 via the cylindrical flexible coupling portion 15.

  Then, continuously from the laser light source of the light emitter 1, the laser light including the light absorption spectrum of the gas to be measured is emitted toward the inside of the exhaust pipe 30 through which the exhaust gas 31 containing the gas to be measured flows, and the laser light is The amount of laser light absorbed by the gas to be measured when the exhaust gas 31 in the exhaust pipe 30 is transmitted and the laser light transmitted through the exhaust gas 31 is received by the light receiving element of the light receiver 11 and transmitted through the exhaust gas 31 The concentration of the gas to be measured in the exhaust gas 30 is continuously measured by the gas concentration measurement system 10a by calculating the concentration of the gas to be measured in the exhaust gas 31 from the amount of absorption of laser light. .

  As shown in FIG. 5, while the concentration of the gas to be measured in the exhaust gas 30 is continuously measured by the gas concentration measuring system 10a, the outside air temperature becomes high, and the exhaust pipe 30 extends in the axial direction 32 of the pipe. Even when extended, the light emitter 1 and the light receiver 11 are fixed in position by the first frame 2 and the second frame 12, so the positions of the light emitter 1 and the light receiver 11 do not shift. Therefore, even if the exhaust pipe 30 extends in the tube axial direction 32, the optical axis 7 of the outgoing laser light of the light emitter 1 and the light receiving axis of the light receiver 11 do not shift.

  At this time, the extension of the exhaust pipe 30 in the axial direction 32 moves the positions of the first side pipe 3 for passing laser light and the second side pipe 13 for passing laser light in the axial direction 32 of the exhaust pipe 30. Also, since the flexible joint portions 5 and 15 are deformed, the first side tube 3 for laser beam passage is obtained even if the light emitter 1 and the light receiver 11 are fixed in position to the first frame 2 and the second frame 12. Also, no large force is applied to the second side tube 13 for passing laser light. Therefore, damage to the first side tube 3 for laser beam passage and the second side tube 13 for laser beam passage can be prevented. In FIG. 7A, a state before the position of the second light transmitting side tube 13 moves is indicated by a solid line, and a state after the position of the second side pipe 13 after the movement is indicated by a two-dot chain line.

  Further, as shown in FIG. 6, while the concentration of the gas to be measured in the exhaust gas 30 is continuously measured by the gas concentration measurement system 10a, the outside air temperature is lowered, and the exhaust pipe 30 is in the pipe axial direction Even if the light emitting device 1 and the light receiving device 11 are contracted to 32, the positions of the light emitting device 1 and the light receiving device 11 do not shift because the light emitting device 1 and the light receiving device 11 are fixed in position by the first frame 2 and the second frame 12. Therefore, even if the exhaust pipe 30 contracts in the tube axial direction 32, the optical axis 7 of the emitted laser light of the light emitter 1 and the light receiving axis of the light receiver 11 do not deviate.

  At this time, the contraction of the exhaust pipe 30 in the axial direction 32 moves the positions of the laser light passing first side pipe 3 and the laser light passing second side pipe 13 in the axial direction 32 of the exhaust pipe 30. Also, since the flexible joint portions 5 and 15 are deformed, the first side tube 3 for laser beam passage is obtained even if the light emitter 1 and the light receiver 11 are fixed in position to the first frame 2 and the second frame 12. Also, no large force is applied to the second side tube 13 for passing laser light. Therefore, damage to the first side tube 3 for laser beam passage and the second side tube 13 for laser beam passage can be prevented. In FIG. 7 (B), the position before the position of the 2nd side pipe | tube 13 for a laser beam passes moves with a solid line, and shows a mode after moving with a dashed-two dotted line.

  If the light emitting device 1 and the light receiving device 11 are fixed by the fixing means such as the first frame 2 and the second frame 12, the light emitting device 1 and the light receiving device 11 may be flexible joints 5 and 15. If it is connected to the first side tube 3 for laser beam passage and the second side tube 13 for laser beam passage without interposition, the expansion or contraction of the exhaust tube 30 in the tube axial direction 32 When the positions of the side tube 3 and the second side tube 13 for passing laser light move in the tube axial direction 32 of the exhaust tube 30, the light emitter 1 and the light receiver 11 are positioned at the first frame 2 and the second frame 12. As a result, a large force is applied to the first side tube 3 for laser beam passage and the second side tube 13 for laser beam passage. Therefore, since there is a possibility that the first side tube 3 for laser beam passage and the second side tube 13 for laser beam passage may be broken, the positions of the light emitter 1 and the light receiver 11 can not be fixed. In addition, a force is also applied to the light emitting device 1 or the light receiving device 11 to which the laser light passing first side tube 3 or the laser light passing second side tube 13 is connected, and as a result, the optical axis may be displaced.

In the gas concentration measurement system according to the present invention, the laser light containing the light absorption spectrum of the gas to be measured is transmitted through the exhaust pipe in which the exhaust gas containing the gas to be measured flows, and the laser light transmits the exhaust gas in the exhaust pipe. A laser type gas concentration measuring device for determining the amount of absorption of the laser light by the gas to be measured at the time of measurement and determining the concentration of the gas to be measured in the exhaust gas from the amount of absorption of the laser light;
A light emitter of the laser type gas concentration measuring apparatus is installed, and a first frame for fixing the position of the light emitter,
A light receiver of the laser type gas concentration measuring apparatus is installed, and a second frame for fixing the position of the light receiver;
A laser through which the laser light passes from the light emitter to the exhaust pipe from the light source, and a laser whose one end is connected to the exhaust pipe so that the pipe axis is inclined with respect to the direction perpendicular to the pipe axis of the exhaust pipe A first side tube for light passage,
A laser through which the laser beam passes from the exhaust pipe to the light receiver on the inside, and a laser whose one end is connected to the exhaust pipe so that the pipe axis is inclined with respect to the direction perpendicular to the pipe axis of the exhaust pipe A second side pipe for light passage,
Have
A light emitter of the laser type gas concentration measuring apparatus is installed in the first frame so that the optical axis of the laser light is inclined with respect to a direction perpendicular to the tube axis of the exhaust pipe, and the laser type gas concentration measurement The receiver of the device is set to the second frame,
The light emitter is connected to the other end of the first side tube for passing laser light through a cylindrical flexible joint, and the light receiver is connected to the laser through a cylindrical flexible joint. Being connected to the other end of the second side pipe for light passage,
A gas concentration measurement system characterized by

  The gas concentration measurement system of the present invention has a laser gas concentration measurement device. That is, the gas concentration measurement system of the present invention is a gas concentration measurement system using a laser gas concentration measurement apparatus. The laser type gas concentration measuring apparatus used in the gas concentration measuring system of the present invention comprises a light emitter provided with a laser light source for emitting a laser beam including a light absorption spectrum of a gas to be measured, and a laser beam transmitted through exhaust gas in an exhaust pipe. And a control unit electrically connected to the light emitter and the light receiver. The control unit has a calculation unit that calculates the gas concentration.

  The laser type gas concentration measuring apparatus according to the gas gas concentration measuring system of the present invention utilizes the fact that the molecules or atoms of the gas have a unique light absorption spectrum, and emits the same emission wavelength band as the light absorption spectrum of the gas to be measured. The laser light is emitted continuously from the laser light source for emitting the laser light to the measurement target space containing the measurement target gas, and the laser light is absorbed by the measurement target gas when the laser light passes through the measurement target space The amount is measured, and the concentration of the gas to be measured is calculated from the amount of absorption of the laser light.

  And as a laser type gas concentration measuring device concerning a gas concentration measuring system of the present invention, a laser beam is continuously emitted from a laser light source which emits a laser beam having the same emission wavelength band as the light absorption spectrum of the gas to be measured. The measurement target space containing the measurement target gas is irradiated, and the absorption amount of the laser light by the measurement target gas when the laser light passes through the measurement target space is measured, and the measurement target gas concentration is determined from the absorption amount of the laser light. The device is not particularly limited as long as it can be obtained by calculation. As a laser type gas concentration measuring apparatus, the laser type gas concentration measuring apparatus described in Unexamined-Japanese-Patent 2001-159605, 2014-102152, 2017-122702 is mentioned, for example. Further, as a laser type gas concentration measuring apparatus, a direct insertion type laser type gas analyzer ZSS (manufactured by Fuji Electric Co., Ltd.), a laser gas analyzer TDL 8000 (manufactured by Yokogawa Electric Co., Ltd.), Laser Gas (manufactured by NEO MONITORS), etc. Can be mentioned.

  The exhaust pipe in which the gas concentration measurement system of the present invention is installed is an exhaust pipe for discharging exhaust gas of various manufacturing facilities or processing facilities, and such facilities include, for example, a manufacturing facility of titanium tetrachloride, Waste incinerators and industrial waste disposal facilities are listed. The material of the exhaust pipe is not particularly limited. For example, in the case of a manufacturing facility of titanium tetrachloride, the material of the exhaust pipe is vinyl chloride, and in the case of a refuse incineration plant, the material of the exhaust pipe is stainless steel In the case of a waste disposal facility, the material of the exhaust pipe is stainless steel. The gas concentration measurement system of the present invention exhibits a particularly excellent effect when the exhaust pipe is made of a material having a large expansion and contraction due to a change in the outside air temperature. The gas concentration measurement system of the present invention exhibits particularly excellent effects when, for example, the material of the exhaust pipe is vinyl chloride, polyethylene, polypropylene, carbon steel, or stainless steel.

  The exhaust gas from the above equipment contains hydrogen chloride, carbon monoxide, carbon dioxide, hydrogen sulfide, oxygen and the like. That is, the gas to be measured according to the gas concentration measurement system of the present invention is hydrogen chloride, carbon monoxide, carbon dioxide, hydrogen sulfide, oxygen or the like. The gas concentration measurement system of the present invention sets the emission wavelength band of the laser beam emitted from the light emitter of the laser type gas concentration measurement device according to the specific light absorption spectrum of the gas to be measured according to the gas to be measured. If it does, concentration measurement according to the kind of measurement object gas contained in exhaust gas is possible.

  In the gas concentration measurement system of the present invention, the optical axis of the laser type gas concentration measurement apparatus is set in the direction perpendicular to the tube axis of the exhaust pipe because the concentration of the measurement target gas in the exhaust gas is low. When it is necessary to install the optical axis of the laser type gas concentration measuring device at an angle with respect to the direction perpendicular to the tube axis of the exhaust pipe, that is, exhaust gas It exhibits particularly excellent effects when the concentration of the gas to be measured is low. In the gas concentration measurement system of the present invention, for example, the measurement target gas is hydrogen chloride, and the measurement of the hydrogen chloride concentration in the exhaust gas having a hydrogen chloride gas concentration of 10 ppm or less; the measurement target gas is hydrogen sulfide; Particularly excellent for measuring hydrogen sulfide concentration in exhaust gas with a concentration of 3 ppm or less, and measuring carbon monoxide concentration in exhaust gas with carbon monoxide gas concentration of 2% or less. Exert a positive effect.

  In the gas concentration measurement system of the present invention, the light emitter of the laser type gas concentration measurement device is installed, the first frame for fixing the position of the light emitter, and the light receiver of the laser type gas concentration measurement device are installed. And a second frame for fixing the position of the container. The first frame and the second frame fix the positions of the light emitter and the light receiver of the laser type gas concentration measuring device so that the optical axis of the laser type gas concentration measuring device does not shift regardless of the change of the outside air temperature. It is a member of Therefore, the material or structure of the first frame and the second frame has a low degree of deformation due to changes in the outside air temperature, and can fix the positions of the light emitter and the light receiver of the laser gas concentration measuring device. A material, a structure, a shape, and the like are selected as appropriate such that effective gas concentration measurement can be performed even if the optical axis does not shift or the optical axis shifts.

  In the embodiment shown in FIG. 1, one end of the upper part of the first frame 2 and one end of the upper part of the second frame 12 are connected by the connecting part 9a1 in order to make it difficult to shift the positions of the first frame 2 and the second frame 12. The other end of the upper portion of the first frame 2 and the other end of the upper portion of the second frame 12 are connected by the connecting portion 9a2. The form example for preventing positional deviation of the first frame and the second frame is not limited to this. For example, as in the form example shown in FIG. 1, one end of the upper portion of the first frame and the second As in the embodiment shown in FIG. 8, one end of the upper part of the frame and the other end of the upper part of the first frame and the other end of the upper part of the second frame are connected by two connecting parts. As in the embodiment in which the vicinity of the upper center of the upper frame and the vicinity of the upper center of the second frame are connected by one connecting portion, or the embodiment shown in FIG. One end of the upper part of the first frame, and the other end of the upper part of the first frame and the other end of the upper part of the second frame are connected by two connection parts, and one end of the lower part of the first frame and the lower part of the second frame One end, and the other end of the lower part of the first frame and the second frame The other end of the section is, embodiments are connected by two connecting portions thereof. FIG. 8 is a schematic view showing an embodiment of the gas concentration measurement system of the present invention, as viewed from above. In FIG. 8, in the gas concentration measurement system 10b, the vicinity of the center of the upper portion of the first frame 2 and the vicinity of the center of the upper portion of the second frame 12 are connected by one connecting portion 9b. FIG. 9 is a schematic view showing an embodiment of the gas concentration measurement system of the present invention, and FIG. 9 (A) is a view of a light emitter and a first side tube for passing laser light as viewed from the side. (B) is the figure which looked at the light-emitting device in the optical axis direction. In FIG. 9, in the gas concentration measurement system 10c, one end of the upper portion of the first frame 2 and one end of the upper portion of the second frame 12 and the other end of the upper portion of the first frame 2 and the other end of the upper portion of the second frame 12 And one end of the lower part of the first frame 2 and one end of the lower part of the second frame 12, and the other end of the lower part of the first frame 2 and the lower part of the second frame 12 The end is connected by two connection parts 9c2.

  Further, in the gas concentration measurement system of the present invention, if the first frame and the second frame are installed on the base or the base, it is possible to make it difficult to shift the positions of the first frame and the second frame, as shown in FIG. As in the embodiment shown, the first frame 2 and the second frame 12 may not be connected at the connecting portion.

  In the gas concentration measurement system according to the present invention, the first side pipe for laser light passage, one end of which is connected to the exhaust pipe, and the pipe axis of the exhaust pipe so that the pipe axis is inclined to the direction perpendicular to the pipe axis of the exhaust pipe. And a second side pipe for passing laser light, one end of which is connected to the exhaust pipe so that the pipe axis is inclined with respect to the vertical direction. The first side pipe for passing laser light is a member that forms a passage path for passing the laser light from the light emitter to the exhaust pipe on the inside, and the second side pipe for passing laser light has an exhaust pipe on the inside Are members forming a passage for passing laser light from the sensor to the light receiver. The inside diameter of the first side tube for passing laser light and the second side tube for passing laser light is expanded and contracted by the change of the outside air temperature, so that the first side tube for passing laser light and the second side tube for passing laser light The diameter at which the optical axis of the laser beam is contained in the tube is appropriately selected even if the position of the lens moves. Also, even if the exhaust pipe expands and contracts due to changes in the outside air temperature, the pipe axis of the first side pipe for passing laser light and the pipe of the second side pipe for passing laser light if the optical axis of the laser light falls within the pipe. The axis may be slightly offset.

  In the gas concentration measurement system of the present invention, the light emitter is set in the first frame and the light receiver is set in the second frame so that the optical axis of the laser light is inclined with respect to the direction perpendicular to the tube axis of the exhaust pipe. It is done. In the gas concentration measurement system of the present invention, the laser light can pass through the exhaust pipe in a direction inclined with respect to the direction perpendicular to the tube axis of the exhaust pipe, so the distance through which the laser light passes through the exhaust gas ( Measurement distance by laser light can be extended. The inclination angle of the optical axis of the laser beam with respect to the direction perpendicular to the tube axis of the exhaust pipe is appropriately selected within a range where a sufficient measurement distance by the laser light can be secured by the inner diameter of the exhaust pipe and the concentration of the measurement object gas in the exhaust gas. However, it is preferably 20 to 80 °, particularly preferably 30 to 60 °.

  In the gas concentration measurement system of the present invention, the light emitter is connected to the other end side of the first side tube for passing laser light through the cylindrical flexible joint, and the light receiver is the cylindrical flexible It is connected to the other end side of the second side pipe for passing laser light through the coupling portion. The shape of the flexible joint is cylindrical. The flexible joint has a cylindrical shape because the inside of the flexible joint becomes a part of the laser light passage path following the first side tube for passing laser light or the second side tube for passing laser light. . Even if the exhaust pipe expands and contracts due to changes in the outside air temperature and the positions of the first side pipe for passing laser light and the second side pipe for passing laser light move, the optical axis of the laser beam is The diameter which fits inside the flexible joint is appropriately selected.

  In the flexible joint, the outside air temperature changes, the exhaust pipe expands and contracts in the pipe axis direction, and the positions of the first side pipe for passing laser light and the second side pipe for passing laser light change. When the positional relationship with the first side tube for light passage and the positional relationship between the light receiver and the second side tube for laser beam passage are shifted, the first side tube for laser beam passage and the first side tube for laser beam passage Due to the change in the position of the second side tube for laser beam passage, the first side tube for laser beam passage and the second side tube for laser beam passage, the first side tube for laser beam passage or the second side for laser beam passage It is not particularly limited as long as it can absorb the force applied to the joint between the pipe and the exhaust pipe, the light emitter or the light receiver, and the material, the wall structure, and the like are appropriately selected. Examples of the material of the flexible joint include, for example, natural rubber, synthetic rubber, vinyl chloride, cloth, and stainless steel. Examples of the wall structure of the flexible joint include a bellows structure, a spherical structure, and the like.

  In the gas concentration measurement system of the present invention, an exhaust pipe in which an exhaust gas containing the gas to be measured flows continuously from the laser light source of the light emitter of the laser type gas concentration measuring device and the laser light including the light absorption spectrum of the gas to be measured When the laser beam emitted toward and emitted through the exhaust pipe passes through the exhaust gas and the laser beam transmitted through the exhaust gas is received by the light receiving element of the light receiver and the laser beam passes through the exhaust gas The concentration of the gas to be measured in the exhaust gas is continuously measured by calculating the concentration of the gas to be measured in the exhaust gas from the amount of absorption of the laser beam by calculating the concentration of the laser light by the gas to be measured. Be done.

  And in the gas concentration measurement system of the present invention, since the light emitter and the light receiver are fixed in position by the first frame and the second frame, the measurement object gas concentration in the exhaust gas is continuously measured. During this time, the exhaust pipe expands and contracts in the pipe axis direction due to changes in the outside air temperature, and the positions of the first side pipe for passing laser light and the second side pipe for passing laser light move in the pipe axis direction of the exhaust pipe Even if the positions of the light emitter and the light receiver do not shift, or even if they shift, the gas concentration can be measured effectively. Therefore, in the gas concentration measuring system of the present invention, while measuring the concentration of the gas to be measured in the exhaust gas continuously, it is expanded and contracted in the axial direction of the exhaust pipe due to the change of the outside air temperature to pass the laser light Even if the positions of the first side tube and the second side tube for passing laser light move in the direction of the tube axis of the exhaust tube, the light emitting axis of the light emitter and the light receiving axis of the light receiver do not deviate Since there is no shift, measurement of the gas concentration to be measured can be continuously performed with high accuracy regardless of expansion and contraction in the axial direction of the exhaust pipe.

  Further, in the gas concentration measurement system of the present invention, the positions of the first side pipe for passing laser light and the second side pipe for passing laser light are expanded and contracted in the axial direction of the exhaust pipe due to changes in the outside air temperature. Since the flexible joint deforms even if it moves in the direction of the tube axis, the light emitter and the light receiver have the first side tube for passing laser light, even if the positions are fixed to the first frame and the second frame. A large force is not applied to the second side tube for passing laser light. Therefore, in the gas concentration measurement system of the present invention, the exhaust pipe expands and contracts in the pipe axis direction due to the change of the outside air temperature, and the positions of the first side pipe for passing laser light and the second side pipe for passing laser light Even in the direction of the tube axis, breakage of the first side tube for passing laser light and the second side tube for passing laser light can be prevented. Further, in the gas concentration measurement system of the present invention, the exhaust pipe expands and contracts in the pipe axis direction due to the change of the outside air temperature, and the positions of the first side pipe for passing laser light and the second side pipe for passing laser light Since the flexible joint deforms even if it moves in the direction of the tube axis, the light emitter and the light receiver have the first side tube for passing laser light, even if the positions are fixed to the first frame and the second frame. Since a large force is not applied to the second side pipe for passing laser light, a force is applied to the light emitter or the receiver to which the first side pipe for passing laser light or the second side pipe for passing laser light is connected. By this, it is also possible to prevent the optical axis from shifting.

  Further, in the gas concentration measurement system of the present invention, even if the tube axis of the first side tube for laser beam passage and the tube axis of the second side tube for laser beam passage are somewhat deviated, the light emission is possible because there is a flexible joint. The light emitter and the light receiver can be fixed to the first frame and the second frame so that the optical axis of the outgoing laser light of the device and the light receiving axis of the light receiver do not shift. Therefore, according to the gas concentration measurement system of the present invention, the gas concentration measurement system can be simply constructed.

  Hereinafter, the present invention will be more specifically described by way of examples, but this is merely an example and does not limit the present invention.

Example 1
The gas concentration measurement system 10a shown in FIG. 1 was installed in the vinyl chloride exhaust pipe (inner diameter: 500 mm) of the titanium tetrachloride production facility from which exhaust gas with a hydrogen chloride gas concentration of about 10 ppm is discharged. The chlorine gas concentration was measured by The fluctuation amount of the light reception amount of the light receiver with respect to the optical axis of the emission laser light of the light emitter due to the expansion and contraction of the exhaust pipe at that time was measured. The results are shown in FIG. In addition, the measurement results of hydrogen chloride gas concentration are also described.
・ Laser gas concentration measuring device: made by Fuji Electric Co., Ltd., direct insertion laser gas analyzer ZSS
・ Laser passage first side pipe and laser passage second side pipe: Material is vinyl chloride, inner diameter 50 mm
· Flexible joint: Material is synthetic rubber, wall structure is bellows structure, inner diameter 80 mm

(Comparative example 1)
The gas concentration measurement system 60 shown in FIG. 12 was installed in the vinyl chloride exhaust pipe (inner diameter: 500 mm) of the titanium tetrachloride production facility from which exhaust gas with a hydrogen chloride gas concentration of about 10 ppm is discharged. The chlorine gas concentration was measured by The fluctuation amount of the light reception amount of the light receiver with respect to the optical axis of the emission laser light of the light emitter due to the expansion and contraction of the exhaust pipe at that time was measured. The results are shown in FIG. In addition, the measurement results of hydrogen chloride gas concentration are also described.
・ Laser gas concentration measuring device: made by Fuji Electric Co., Ltd., direct insertion laser gas analyzer ZSS
・ Laser passage first side pipe and laser passage second side pipe: Material is vinyl chloride, inner diameter 50 mm

DESCRIPTION OF SYMBOLS 1 Light emitter 2 First frame 3 First side tube 4 for laser beam passage 4 Flange member for light emitter installation 5, 15 Flexible joint portion 6 Mounting flange portion 7 of light emitter Optical axis of laser light, of emitted laser light of light emitter Optical axis 9a1, 9a2, 9b, 9c1, 9c2 Connection part 10a, 10b, 10c, 10d Gas concentration measurement system 11 Photodetector 12 Second frame 13 Second side tube 14 for laser light passage 14 Flange member for light receiver installation 16 Photodetector Mounting flange 21 outer frame 22 emitter lower fixed frame 23 emitter upper fixed frame 24 emitter left fixed frame 25 emitter right fixed frame 29 exhaust pipe tube axis 30 exhaust pipe 31 exhaust gas 32 Tube axial direction 33 of the exhaust pipe Direction 121 perpendicular to the pipe axis of the exhaust pipe Outer frame portion 122 Photoreceiver lower fixed frame portion 124 Left fixed frame portions 125 photoreceiver right fixing frame portion

Claims (5)

The laser by the gas to be measured when the laser light including the light absorption spectrum of the gas to be measured is transmitted through the exhaust pipe in which the exhaust gas containing the gas to be measured flows, and the laser light transmits the exhaust gas in the exhaust pipe A laser type gas concentration measuring device for determining the amount of absorption of light and determining the concentration of the gas to be measured in the exhaust gas from the amount of absorption of the laser light;
A light emitter of the laser type gas concentration measuring apparatus is installed, and a first frame for fixing the position of the light emitter,
A light receiver of the laser type gas concentration measuring apparatus is installed, and a second frame for fixing the position of the light receiver;
A laser through which the laser light passes from the light emitter to the exhaust pipe from the light source, and a laser whose one end is connected to the exhaust pipe so that the pipe axis is inclined with respect to the direction perpendicular to the pipe axis of the exhaust pipe A first side tube for light passage,
A laser through which the laser beam passes from the exhaust pipe to the light receiver on the inside, and a laser whose one end is connected to the exhaust pipe so that the pipe axis is inclined with respect to the direction perpendicular to the pipe axis of the exhaust pipe A second side pipe for light passage,
Have
A light emitter of the laser type gas concentration measuring apparatus is installed in the first frame so that the optical axis of the laser light is inclined with respect to a direction perpendicular to the tube axis of the exhaust pipe, and the laser type gas concentration measurement The receiver of the device is set to the second frame,
The light emitter is connected to the other end of the first side tube for passing laser light through a cylindrical flexible joint, and the light receiver is connected to the laser through a cylindrical flexible joint. Being connected to the other end of the second side pipe for light passage,
Gas concentration measurement system characterized by   The gas concentration measurement system according to claim 1, wherein the gas to be measured is hydrogen chloride, carbon monoxide, carbon dioxide, hydrogen sulfide or oxygen.   The gas concentration measurement system according to claim 1, wherein the gas to be measured is hydrogen chloride, and the concentration of hydrogen chloride in the exhaust gas is 10 ppm or less.   The gas concentration measurement system according to any one of claims 1 to 3, wherein a material of the exhaust pipe is polyethylene, polypropylene, carbon steel or stainless steel. The gas concentration measurement system according to any one of claims 1 to 4, wherein the first frame and the second frame are connected at a connection portion.