JP2006258706A - Dust measuring method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dust measuring device capable of detecting the degree of the stain of the dust in an irradiation part and/or a light receiving part. <P>SOLUTION: The dust measuring device is provided with a light emitting means 66 for emitting the measurement light, a light receiving means 68 for converting the detected light to a measurement signal, a first optical fiber 50 connected to an irradiation/light receiving part, a second optical fiber 56 connected to a light receiving/irradiation part, and a dust concentration computing means 82 for computing the dust concentration based on the measurement signal from the light receiving means 68. When measuring the dust in a measurement region, the first optical fiber 50 is connected to the light emitting means 66, and the second optical fiber 56 is connected to the light receiving means 56, and the dust concentration in the normal connection state is measured. Next, the second optical fiber 56 is connected to the light emitting means 66, and the first optical fiber 50 is connected to the light receiving means 68, and the dust concentration in the inverse connection state is measured. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a dust measuring method and apparatus for measuring the concentration of dust contained in a gas flow flowing in a pipe.

  Conventionally, as a dust measuring device for measuring the concentration of dust contained in a gas (for example, city gas, LP gas, etc.) flowing in a pipe (for example, a gas pipe), a light emitting means for emitting measurement light , An irradiating unit for irradiating the measurement light from the light emitting source toward the measurement region, a light receiving unit for receiving the detected light from the measurement region, and a light receiving means for converting the detected light from the light receiving unit into a measurement signal And a dust concentration calculating means for calculating a dust concentration based on a measurement signal from the light receiving means, and the irradiation unit and the light receiving unit are provided in a detection unit inserted into the pipe. The irradiation unit and the light emitting unit are connected by a first optical fiber, and the light receiving unit and the light receiving unit of the detection unit are connected by a second optical fiber (for example, see Patent Document 1).

  In such a measurement apparatus, the measurement light from the light emitting means is guided to the irradiation unit through the first optical fiber, and the measurement light is irradiated from the irradiation unit toward the measurement area. Further, the detected light from the measurement area is received by the light receiving unit and guided to the light receiving means through the second optical fiber. The light receiving means converts the light to be measured into a measurement signal, and the dust concentration calculating means calculates the dust concentration based on the measurement signal, thus measuring the concentration of dust contained in the gas flow flowing through the measurement area. Is done.

JP 2004-205217 A

  However, the dust measuring apparatus described above has the following problems to be solved. First, in such a dust measuring apparatus, a transparent irradiation cover member and a light receiving cover member are provided in the irradiation unit and the light receiving unit of the detection unit so that dust in the pipe does not enter the detection unit. The measurement light is irradiated toward the measurement region through the irradiation cover member, and the detected light is received through the light receiving cover member. However, when used in a dusty environment, dust may adhere to the surface of the irradiation cover member and / or the light receiving cover member, and when dust adheres to these surfaces, it irradiates the measurement area. There is a problem in that the measurement light and / or the light to be detected from the measurement area are blocked by the adhering dust, and the dust concentration in the measurement area cannot be measured accurately due to this.

  Second, when measuring the concentration of dust contained in the gas flow flowing in the pipe, it is necessary to position the detector unit in a predetermined measurement area in the pipe through a bent pipe (so-called curved pipe). When the detection unit is positioned in the measurement area through the curved pipe, there is a problem that it is difficult to grasp the position of the detection unit and it is difficult to position the detection unit in a desired measurement area.

  Third, in order to position the detection unit in the measurement area through the curved tube, the first and second optical fibers connecting the irradiation unit and the light receiving unit and the light emitting unit and the light receiving unit of the detection unit can be bent. However, if it is built in such a tube, there is a risk of the detector unit shaking due to the gas flow flowing in the piping when measuring the dust concentration. It becomes difficult to measure accurately.

The objective of this invention is providing the dust measuring method and apparatus which can know the grade of the dirt of the dust in an irradiation part and / or a light-receiving part.
Another object of the present invention is to provide a dust measuring device capable of accurately measuring the dust concentration even in a configuration in which the detection unit is positioned in the pipe through the curved pipe.

  Still another object of the present invention is to provide a dust measuring method capable of accurately measuring a dust concentration by positioning an irradiation unit and a light receiving unit in a predetermined measurement area in a pipe.

The dust measuring apparatus according to claim 1 of the present invention includes a light emitting means for emitting measurement light for measuring dust concentration in a measurement area, and a light receiving means for converting detected light from the measurement area into a measurement signal. A detection unit having an irradiation / light-receiving unit and a light-receiving / irradiation unit, inserted into the measurement area, a first optical fiber connected to the irradiation / light-receiving unit of the detection unit, and the detection unit A second optical fiber connected to the light receiving / irradiating unit of the unit, and a dust concentration calculating means for calculating a dust concentration based on a measurement signal from the light receiving means,
When measuring dust in the measurement area, the first optical fiber is connected to the light emitting means, the second optical fiber is connected to the light receiving means, and the measurement light from the light emitting means is the first light. Irradiated from the irradiation / light receiving unit toward the measurement region through a fiber, and the detected light from the measurement region is received by the light receiving unit from the light receiving / irradiating unit through the second optical fiber, and the dust concentration calculating unit Calculates the dust concentration in the positive connection state of the first and second optical fibers, and then the second optical fiber is connected to the light emitting means and the first optical fiber is connected to the light receiving means. The measurement light from the light emitting means is irradiated from the light receiving / irradiating unit toward the measurement region through the second optical fiber, and the detected light from the measurement region is the irradiation / light receiving unit. The first is received in said receiving means through an optical fiber, the dust concentration calculation means and calculates the dust concentration in the reverse connection state of the first and second optical fiber.

  Moreover, the dust measuring apparatus according to claim 2 of the present invention is provided with a dirt determination unit for determining dust contamination of the irradiation / light receiving unit and / or the light receiving / irradiating unit, The contamination is determined based on a dust concentration value in a normal connection state of the first and second optical fibers and a dust concentration value in a reverse connection state thereof.

  In the dust measuring apparatus according to claim 3 of the present invention, the first and second optical fibers are built in a flexible tube, the detection unit is attached to a front end portion of the flexible tube, and the dust concentration calculation is performed. The means is characterized by calculating an average dust concentration obtained by averaging the dust concentrations in a predetermined measurement time.

Moreover, the dust measuring apparatus according to claim 4 of the present invention receives a light emitting means for emitting measurement light, an irradiation unit for irradiating the measurement light toward the measurement area, and light to be detected from the measurement area. A light receiving unit; a light receiving unit that converts light to be detected from the light receiving unit into a measurement signal; a first optical fiber for guiding the measurement light from the light emitting unit to the irradiation unit; and a target to be detected from the light receiving unit. A dust measuring device comprising: a second optical fiber for guiding light to the light receiving means; and a dust concentration calculating means for calculating a dust concentration based on a measurement signal from the light receiving means,
The first and second optical fibers are built in a flexible tube, the detection unit is attached to the front end of the flexible tube, and the dust concentration calculating means averages the dust concentration in a predetermined measurement time. Is calculated.

According to a fifth aspect of the present invention, there is provided a dust measuring method comprising: a light emitting means for emitting measurement light for measuring dust concentration in a measurement area; and a light receiving means for converting detected light from the measurement area into a measurement signal. Means, a detection unit having an irradiation / light-receiving unit and a light-receiving / irradiation unit, a first optical fiber connected to the irradiation / light-receiving unit of the detection unit, and the light-receiving / irradiation unit of the detection unit A dust measuring method for measuring a concentration of dust contained in a gas flow flowing through a measurement area using a dust measuring device having a second optical fiber connected to
The first optical fiber is connected to the light emitting means, the second optical fiber is connected to the light receiving means, and measurement light from the light emitting means is passed through the first optical fiber from the irradiation / light receiving section to the measurement area. And the detected light from the measurement area is received by the light receiving means from the light receiving / irradiating section through the second optical fiber, and the dust concentration in the positive connection state of the first and second optical fibers is received. Next, the second optical fiber is connected to the light emitting means, the second optical fiber is connected to the light receiving means, and the measurement light from the light emitting means is received through the second optical fiber. The first and second lights are irradiated from the irradiation unit toward the measurement area, and light to be detected from the measurement area is received from the irradiation / light reception unit through the first optical fiber to the light receiving unit. And calculating the dust concentration in the reverse connection state of Aiba.

Furthermore, the dust measuring method according to claim 6 of the present invention receives a light emitting means for emitting measurement light, an irradiation unit for irradiating the measurement light toward the measurement area, and light to be detected from the measurement area. A light receiving unit; a light receiving unit that converts light to be detected from the light receiving unit into a measurement signal; a first optical fiber for guiding the measurement light from the light emitting unit to the irradiation unit; and a target to be detected from the light receiving unit. A measurement area in a pipe using a dust measuring device comprising: a second optical fiber for guiding light to the light receiving means; and a dust concentration calculating means for calculating a dust concentration based on a measurement signal from the light receiving means. A dust measuring method for measuring the concentration of dust flowing through
From the state where the calculated value of the dust concentration calculating means has changed from outside the measurable range of the dust concentration to within the measurable range of the dust concentration, a predetermined amount of the irradiation unit and the light receiving unit are further inserted into the measurement area. Positioning and measuring the concentration of dust in the measurement area.

  According to the dust measuring apparatus of the first aspect of the present invention and the dust measuring method of the fifth aspect of the present invention, the detector unit is provided with the irradiation / light receiving unit and the light receiving / irradiating unit, and the irradiation / light receiving unit has the first One optical fiber is connected, and the second optical fiber is connected to the light receiving / irradiating unit. When measuring the concentration of dust contained in the gas flow flowing through the measurement area, first and second optical fibers are first connected positively, and the measurement light from the light emitting means is transmitted through the first optical fiber to irradiate / receive light. Irradiated from the part toward the measurement area. Then, the detected light from the measurement area is received from the light receiving / irradiating unit and transmitted to the light receiving means through the second optical fiber, and the dust concentration calculating means calculates the dust concentration based on the measurement signal of the light receiving means. Next, the first and second optical fibers are reversely connected, and the measurement light from the light emitting means is transmitted through the second optical fiber and irradiated from the light receiving / irradiating unit toward the measurement area. Then, the detected light from the measurement area is received from the irradiation / light receiving unit and transmitted to the light receiving means through the first optical fiber, and the dust concentration calculating means calculates the dust concentration based on the measurement signal of the light receiving means. As described above, the dust concentrations in the forward connection state and the reverse connection state of the first and second optical fibers are measured. Therefore, when the concentration values of the dust concentrations in both connection states are almost equal, the irradiation / light receiving unit and the light receiving unit of the detection unit / When the irradiated part is kept clean and normal measurement is possible, and when the density values of the dust concentrations in both connected states are significantly different, the irradiated / light receiving part and the received / irradiated part are dirty with dust. Thus, the dust concentration can be accurately measured by judging whether the value is normal or abnormal based on the concentration values of these dust concentrations.

  According to the dust measuring apparatus of the second aspect of the present invention, the dirt / light-receiving part of the detection unit and / or the dirt judging means for judging the dirt of the light / light-irradiating part are provided. Since this dirt determination means determines the dirt based on the dust concentration value in the normal connection state and the reverse connection state of the first and second optical fibers, the presence / absence of dirt in the irradiation / light receiving unit and / or the light receiving / receiving unit is automatically determined. Can be determined automatically. In connection with this dirt determination means, an alarm means or the like may be provided. In this case, the operator can be notified of the occurrence of dirt by the alarm means.

  Moreover, according to the dust measuring apparatus of Claim 3 and Claim 4 of this invention, since the 1st and 2nd optical fiber was incorporated in the flexible tube, it was attached to the front-end | tip part of a flexible tube. The detector unit can be positioned as required in the measurement area in the pipe through the curved pipe. In addition, the dust concentration calculation means calculates the average dust concentration by averaging the dust concentration during the predetermined measurement time, so even if the detector unit shakes due to the gas flow in the pipe, the influence is reduced and included in the gas flow. It is possible to accurately measure the concentration of dust.

  According to the dust measuring method of the sixth aspect of the present invention, when the irradiation unit and the light receiving unit are inserted into a predetermined measurement area in the pipe, the dust measuring device is maintained in the measurement state, and the insertion is performed in this state. The irradiation unit and the light receiving unit are inserted through a tube (for example, a curved tube or a straight tube). When the irradiation unit and the light receiving unit move in the insertion tube, the measurement light from the irradiation unit is reflected by the inner surface of the insertion tube, and the detected light of the light receiving unit becomes very strong and falls outside the measurable range. On the other hand, when the irradiation unit and the light receiving unit reach the pipe through the insertion tube, the measurement light from the irradiation unit is not reflected by the inner surface of the pipe, and the detected light of the light receiving unit becomes very weak and falls within the measurable range. Become a level. For this reason, when the calculated value of the dust concentration calculating means changes from outside the measurement range (so-called measurement range over) to within the measurement range, it can be determined that the irradiation unit and the light receiving unit have reached the pipe through the insertion tube. By further inserting a predetermined amount considering the diameter of the pipe from the state, the irradiating part and the light receiving part can be positioned in a desired measurement area, thereby reducing the concentration of dust contained in the gas flow flowing in the pipe. It can be measured accurately.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best embodiment of a dust measuring device (dust measuring method) according to the invention will be described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view schematically showing an example of a piping structure for measuring dust concentration using the dust measuring device of one embodiment, and FIG. 2 is an enlarged view of the detection unit of the dust measuring device of FIG. FIG. 3 is a block diagram showing a control system of the dust measuring device of FIG. 1, and FIG. 4 is a diagram showing the detector unit of FIG. FIG. 5 is a flowchart showing the flow of dust concentration measurement using the dust measuring apparatus of FIG. 1.

  1 and 2, the illustrated dust measuring device 2 is included in a gas (for example, city gas, LP gas, etc.) flowing through a fluid flow path 8 defined by a piping 6 of the fluid piping structure 4, for example, a gas piping. Used to measure the concentration of dust such as dust. The dust measurement device 2 includes a detection unit 10 and a flexible tube 12 attached to the base side of the detection unit 10, and the flexible tube 12 is detachable from the measurement device main body 14 (see FIG. 3). Connected. In the illustrated example, a main opening / closing valve 16 is disposed at a predetermined portion of the pipe 6 of the fluid piping structure 4, and diffusion pipes 18, 20 are disposed upstream and downstream of the main opening / closing valve 16. One ends of the pipes 18 and 20 are connected to the pipe 6, and open / close ball valves 22 and 24 are provided at the other ends thereof. The diffusion tubes 18 and 20 function as an insertion tube for inserting the detection unit 10, and the detection unit 10 is positioned in the measurement area 26 in the pipe 6 through the diffusion tube 18 (or 20) as will be described later. .

  The detection unit 10 includes a detection unit main body 28, and the detection unit main body 28 is attached to the distal end portion of the flexible tube 12. A concave portion 30 is provided at an axially intermediate portion of the detector main body 28, and an irradiation / light receiving portion 32 (functioning as an irradiation portion in a positive connection state) is provided on one end side (left side in FIG. 2) of the concave portion 30. A light receiving / irradiating unit 34 (functioning as a light receiving unit in the positive connection state) is provided on the other end side (right side in FIG. 2) of the recess 30, and the irradiation / light receiving unit 32 and the light receiving / irradiating unit 34 are substantially opposed to each other. Are arranged as follows. The irradiation / light receiving unit 32 is provided with an irradiation / light receiving port 36, an irradiation / light receiving cover 39 is attached so as to seal the irradiation / light receiving port 36, and the light receiving / irradiating unit 34 has a light receiving / irradiation port 38. A light receiving / irradiating cover 40 is provided so as to seal the light receiving / irradiating port 38.

  The detection unit main body 28 is further provided with a first passage 42 communicating with the irradiation / light-receiving opening 36 and a second passage 44 communicating with the light-receiving / irradiation opening 38. The first passage 42 extends linearly toward the irradiation / light reception port 36, and the second passage 44 extends substantially parallel to the first passage 42 and then bends and extends toward the light reception / irradiation port 38. In relation to this, a reflecting mirror 46 is disposed at the bent portion of the second passage 44. The reflecting mirror 46 is attached to the distal end cover 48, and the reflecting mirror 46 is attached to the detection unit main body 28 by attaching the distal end cover 48 to the distal end portion of the detection unit main body 28.

  The first optical fiber 50 is connected to the irradiation / light receiving unit 32 of the detection unit 10. The first optical fiber 50 includes a fiber 52 that transmits measurement light or detected light as will be described later, and a protective coating 54 that covers the fiber 52, and at one end thereof, the tip of the fiber 52 that protrudes from the protective coating 54. Is inserted into the first passage 42 of the detector main body 28 and positioned. The second optical fiber 56 is connected to the light receiving / irradiating unit 34. Similar to the first optical fiber 52, the second optical fiber 56 includes a fiber 58 and a protective coating 60 covering the fiber 58, and at one end thereof, the tip of the fiber 58 protruding from the protective coating 60 is the detection unit main body. 28 inserted into the second passage 42 and positioned.

  The first and second optical fibers 50 and 56 are built in the flexible tube 12. The flexible tube includes a flexible flexible tube 62 formed of, for example, stainless steel, and a protective tube 64 that covers the flexible tube 62. The first and second optical fibers 50 and 56 are formed of the flexible tube 62. It extends inside. A connecting tool (not shown) is provided at the other end of the flexible tube 12, and the connecting part is detachably connected to a connecting part (not shown) of the measuring apparatus main body 14 (see FIG. 3). As will be described later, it is connected to the measuring apparatus main body 14.

  In this embodiment, the 1st and 2nd optical fibers 50 and 56 are comprised so that normal connection and reverse connection are possible. When the positive connection is made, as shown in FIG. 3, the first optical fiber 50 is connected to the light emitting means 66 built in the measuring apparatus main body 14, and the second optical fiber 56 is received by the light receiving means 68 built in the measuring apparatus main body 14. Connected to. Accordingly, the measurement light from the light emitting means 66 is transmitted to the irradiation / light receiving unit 32 through the first optical fiber 50, irradiated from the irradiation / light receiving unit 32 toward the measurement area 26, and received by the light receiving / irradiating unit 34. The detected light is reflected by the reflecting mirror 46 and then transmitted to the light receiving means 68 through the second optical fiber 56. When the connection is reverse, the second optical fiber 56 is connected to the light emitting means 66 and the first optical fiber 50 is connected to the light receiving means 68, contrary to the above. Accordingly, the measurement light from the light emitting means 66 is transmitted through the second optical fiber 56, reflected by the reflecting mirror 46, guided to the light receiving / irradiating unit 34, and irradiated from the light receiving / irradiating unit 34 toward the measurement region 26. Then, the detected light received by the irradiation / light receiving unit 32 is transmitted to the light receiving means 68 through the first optical fiber 50. The light emitting means 66 can be composed of, for example, a laser light emitting element that emits near infrared laser light, and the light receiving means 68 can be composed of, for example, a CCD.

  A light shielding member 70 is provided in the recess 30 of the detection unit 10. The light shielding member 70 prevents the measurement light from the irradiation / light receiving unit 32 from being directly received by the light receiving / irradiating unit 34 in the positive connection state of the first and second optical fibers 50 and 56, and In the reverse connection state, the measurement light from the light receiving / irradiating unit 34 is prevented from being directly received by the irradiation / light receiving unit 32.

  The control system of the dust measuring apparatus 2 will be described mainly with reference to FIG. The measurement apparatus main body 14 incorporates a controller 72 composed of, for example, a microprocessor, an operation means 74 that is operated when performing a measurement operation, a display means 76 for displaying measurement results, and an alarm. An alarming means 78 for emitting is provided. The controller 72 includes control means 80 for controlling the operation of the display device 76, alarm means 78, etc., dust concentration calculation means 82 for calculating the dust concentration contained in the gas flow, and irradiation of the irradiation / light receiving unit 32. A dirt determination means 84 for determining dirt on the light receiving cover 39 and / or the light receiving / irradiation cover 40 of the light receiving / irradiating section 34, a time measuring means 86 for measuring the measuring time, and the measured dust concentration. And a memory 88 for storage. The dust concentration calculating means 82 in this embodiment calculates the dust concentration calculating means 90 for calculating the dust concentration based on the measurement signal from the light receiving means 68 and the average value of the dust concentration measured over a predetermined measurement time. The average dust concentration means 92 is configured to measure the average dust concentration at a predetermined measurement time as a dust concentration value. In general, there is a predetermined relationship between the amount of dust in the gas flow and the light to be detected. When the amount of dust is large (or small), scattering of measurement light by the dust is large (or small). The amount of detected light received is increased (or decreased), and accordingly, the signal level of the measurement signal of the light receiving means 68 is also increased (or decreased). Based on the measurement signal of the light receiving means 68, the dust concentration in the gas flow is calculated. The calculation of the dust concentration by the dust concentration calculation means 82 can apply various calculation methods known per se. For example, the calculation value calculated by the dust concentration calculation means 90 may be used as the dust concentration. Good.

  The operation means 74 includes various operation switches such as a power switch 94. When the power switch 94 is turned on, the measurement device main body 14 is operated, and when the power switch 94 is turned off, the operation of the measurement device main body 14 is stopped. . The display device 76 is composed of, for example, a liquid crystal display device, a CRT, or the like, and displays a dust concentration value calculated by the dust concentration calculation means 82 and the like. The alarm means 78 is constituted by an alarm lamp, an alarm buzzer, etc., and is configured to operate based on the determination result when the dirt determination means 84 determines that there is dirt as will be described later.

  The measurement of the dust concentration of the gas flowing through the pipe 6 is performed as follows, for example. First, as shown in FIG. 1, an introduction pipe (not shown) is detachably attached to an open / close ball valve 22 connected to a diffusion pipe 18 to be inserted (functions as an insertion pipe), and the inside of the introduction hole of the introduction pipe is inserted. Then, the detecting unit 10 is inserted and held, and the open / close ball valve 22 is opened to be introduced through the introduction hole of the introduction pipe and the open / close ball valve 22 in the insertion direction indicated by the arrow 92 (see FIG. 1). In this embodiment, the diffusion tube 18 is bent downward after being bent to the right in FIG. 1, but the detection unit 10 of the dust measuring device 2 is attached to the distal end portion of the flexible tube 12, and the flexible tube 12 itself is Since it has flexibility, as the detection unit 10 is inserted, the flexible tube 12 bends along the shape of the diffusion tube 18 and is bent so that the detection unit 10 is piped through the diffusion tube 18. 6 fluid flow paths 8 can be inserted.

  When the detection unit 10 is inserted, the first and second optical fibers 50 and 56 are connected to the measurement apparatus main body 14 in a positive connection state, the power switch 94 is turned on, and the dust measurement apparatus 2 is inserted in the measurement state. . In this measurement state, the measurement light from the light emitting means 66 is irradiated from the irradiation / light receiving unit 32 toward the measurement region 26 through the first optical fiber 50, and the detected light from the measurement region 26 is applied to the light receiving / irradiation unit 34. The light is received and reflected by the reflecting mirror 46 and then sent to the light receiving means 68 through the second optical fiber 56, and the dust concentration calculating means 82 calculates the dust concentration as described later.

  While the detection unit 10 moves in the diffusion tube 18, since the inner peripheral surface of the diffusion tube 18 is located in the vicinity of the measurement area 26, the measurement light irradiated from the irradiation / light receiving unit 32 is transmitted through the diffusion tube 18. Since the light is reflected by the inner peripheral surface, the amount of the detected light received by the light receiving / irradiating unit 34 is very large, and the dust concentration calculated by the dust concentration calculating means 90 exceeds the measurable range. It will be a thing. On the other hand, when the detection unit 10 passes through the diffusion tube 18 and reaches the inside of the pipe 6, the measurement light from the irradiation / light reception unit 32 is not reflected by the inner peripheral surface of the diffusion tube 18, so the light reception / irradiation unit 34. The amount of light to be detected received at is reduced and falls within the measurable range. That is, as shown in FIG. 4, for example, when the detection unit 10 passes through the diffusion pipe 18 and reaches the pipe 6 at time T <b> 1, the dust concentration value is suddenly displayed on the display means 76 of the measurement apparatus main body 14. Then, by further inserting the detection unit 10 from the position where it reaches the pipe 6, the dust concentration value rapidly decreases and the concentration of dust contained in the gas flow flowing in the pipe 6 is measured. It becomes like this. For this reason, as understood from FIG. 4, when a predetermined amount of the flexible tube 12 is further inserted with the time T1 as a reference (in other words, after the dust concentration value is displayed on the display means 76). The predetermined insertion amount corresponds to the distance at which the detection unit 10 is inserted into the pipe 6. By inserting this predetermined amount, the detection unit 10 is inserted into a predetermined measurement area 26 in the fluid flow path 8 of the pipe 6. This makes it possible to accurately measure the concentration of dust contained in the gas flow flowing in the direction indicated by the arrow 90 (see FIG. 1).

  After the detection unit 10 is positioned in the predetermined measurement area 26 in the pipe 6 as described above, the dust concentration is measured as follows. Referring mainly to FIGS. 3 and 5, first, measurement of the dust concentration in the positive connection state of the first and second optical fibers 50 and 56 is started (step S1), and the concentration of dust contained in the gas flow is started. Is measured (step S2). That is, the measurement light from the light emitting means 66 is irradiated from the irradiation / light receiving unit 32 toward the measurement region 26 through the first optical fiber 50, and the detected light from the measurement region 26 is received by the light receiving / irradiating unit 34, After being reflected by the reflecting mirror 4, it is sent to the light receiving means 68 through the second optical fiber 56. The light receiving means 68 generates a measurement signal corresponding to the amount of light to be detected. The dust concentration calculation means 90 calculates the dust concentration based on the measurement signal, and the calculated dust concentration value is stored in the memory 88. . The dust concentration is measured for a predetermined measurement time, for example, about 2 seconds. When the dust concentration is measured over a predetermined measurement time, the process proceeds from step S3 to step S4, where the average concentration calculating means 92 calculates the average value of the measured dust concentration, and this average dust concentration is used as the measured dust concentration. Stored in the memory 88.

  Next, the first and second optical fibers 50 and 56 are reversely connected in order to confirm whether the irradiation / light-receiving unit 32 and / or the light-receiving / irradiation unit 34 is contaminated with dust or the like (step S5). ), The measurement of the dust concentration in the reverse connection state is started (step S6), and the concentration of the dust contained in the gas flow is measured (step S7). That is, the measurement light from the light emitting means 66 passes through the second optical fiber 56, is reflected by the reflecting mirror 46, and then is irradiated from the light receiving / irradiating unit 34 toward the measurement area 26, and the detected light from the measurement area 26 is The light is received by the irradiation / light receiving unit 32 and sent to the light receiving means 68 through the first optical fiber 50. As described above, the light receiving means 68 generates a measurement signal corresponding to the amount of light to be detected, the dust concentration calculating means 90 calculates the dust concentration based on this measurement signal, and the measurement of the dust concentration is as follows. A predetermined measurement time is taken. Then, when the dust concentration is measured for a predetermined measurement time in the reverse connection state, the process proceeds from step S8 to step S9, and the average concentration calculation means 92 calculates the average value of the measured dust concentration, and this average dust concentration is calculated. The measured dust concentration is stored in the memory 88.

  Thereafter, the dirt determination means 84 determines the presence or absence of dirt based on the measured dust concentration value in the normal connection state and the measured dust concentration value in the reverse connection state (step S10), and is opposite to the measurement dust concentration value in the normal connection state. If the measured dust concentration value in the connected state is substantially equal, for example, if the error is within 20%, the dirt determination means 84 determines that there is no dirt, and the process proceeds from step S11 to step S12. The measured dust concentration value in the stored normal connection state is displayed on the display means 76, and thus the dust concentration can be measured while confirming dust contamination.

  On the other hand, if the measured dust concentration value in the normal connection state and the measured dust concentration value in the reverse connection state are significantly different, for example, if the error exceeds 20%, the dirt determination means 84 determines that there is dirt, and step Proceeding from step S11 to step S13, the control means 80 generates a dust contamination signal, and displays the measured dust concentration value in the normal connection state and the measurement dust concentration in the reverse connection state stored in the memory 88 based on the dust contamination signal. The operator can easily know that the irradiation / light receiving unit 32 and / or the light receiving / irradiating unit 34 are dirty by displaying on the means 76 and viewing the display content. Further, the alarm unit 78 is activated based on the dust contamination signal (step S14), and it can be known that the contamination is generated by the action of the alarm unit 78.

  When the dirt is generated in this way, the dust concentration cannot be measured accurately. Therefore, the operator stops measuring the dust concentration, pulls out the detection unit 10 from the pipe 6, and the irradiation / light receiving unit 32 and The dust adhering to the light receiving / irradiating unit 34 is removed, and then the dust concentration is measured again in the same manner as described above.

  In this embodiment, the detection unit 10 is attached to the distal end of the flexible tube 12, and the detection unit 10 may be shaken by the gas flow flowing in the pipe 6, and the dust concentration may not be accurately measured when the detection unit 10 is shaken greatly. However, as described above, the dust concentration is measured over a predetermined measurement time and the average value is used as the measured dust concentration. Therefore, it is possible to accurately measure the dust concentration by reducing the influence of the shaking movement of the detection unit 10. it can.

  Although one embodiment of the dust measuring apparatus (dust measuring method) according to the present invention has been described above, the present invention is not limited to such an embodiment, and various modifications or corrections can be made without departing from the scope of the present invention. Is possible.

  For example, in the embodiment described above, the dirt determination is automatically performed by the dirt determination unit 84. However, it is not necessary to automatically perform such a determination, and the dust concentration in the normal connection state and the dust concentration in the reverse connection state are not necessary. Both may be displayed on the display means 76, and based on the measurement result, the operator may determine the presence or absence of dust dirt.

  In the above-described embodiment, in order to confirm the presence or absence of dust dirt, the first and second optical fibers 50 and 56 are connected in the normal connection state, the dust concentration is measured, and these are further set in the reverse connection state. In this state, the dust concentration is measured, but when it is not necessary to check the presence or absence of dust, the dust concentration is measured with the first and second optical fibers 50 and 56 connected in the positive connection state. You can do it.

Sectional drawing which shows simply an example of the piping structure which measures a dust density | concentration using the dust measuring apparatus of one Embodiment. The partial expanded sectional view which expands and shows the detection part unit of the dust measuring device of FIG. The block diagram which shows the control system of the dust measuring device of FIG. The figure which shows the change of an output level when inserting the detection part unit of FIG. 1 into the measurement area in piping through an insertion pipe. The flowchart which shows the flow of a measurement of dust concentration using the dust measuring apparatus of FIG.

Explanation of symbols

2 Dust measuring device 6 Piping 10 Detector unit 12 Flexible tube 14 Measuring device body 16 Main on-off valve 18, 20 Radiation tube (insertion tube)
28 Detection unit body 32 Irradiation / light reception unit
34 Light receiving / irradiating section 50 First optical fiber 56 Second optical fiber 66 Light emitting means 68 Light receiving means 72 Controller 82 Dust concentration calculating means 84 Dirt determining means

Claims (6)

A light emitting means for emitting measurement light for measuring dust concentration in the measurement area; a light receiving means for converting detected light from the measurement area into a measurement signal; and an irradiation / light receiving section and a light receiving / irradiation section. , A detection unit inserted into the measurement area, a first optical fiber connected to the irradiation / light reception unit of the detection unit, and a second light connected to the light reception / irradiation unit of the detection unit A dust concentration calculating means for calculating a dust concentration based on a measurement signal from the fiber and the light receiving means,
When measuring dust in the measurement area, the first optical fiber is connected to the light emitting means, the second optical fiber is connected to the light receiving means, and the measurement light from the light emitting means is the first light. Irradiated from the irradiation / light receiving unit toward the measurement region through a fiber, and the detected light from the measurement region is received by the light receiving unit from the light receiving / irradiating unit through the second optical fiber, and the dust concentration calculating unit Calculates the dust concentration in the positive connection state of the first and second optical fibers, and then the second optical fiber is connected to the light emitting means and the first optical fiber is connected to the light receiving means. The measurement light from the light emitting means is irradiated from the light receiving / irradiating unit toward the measurement region through the second optical fiber, and the detected light from the measurement region is the irradiation / light receiving unit. The first is received through an optical fiber to said light receiving means, wherein the dust concentration calculation means dust measuring device and calculates the dust concentration in the reverse connection state of the first and second optical fiber.   Dirt determination means for determining dust contamination of the irradiation / light receiving unit and / or the light receiving / irradiation unit is provided, and the dirt determination unit is configured to detect a dust concentration value in a positive connection state of the first and second optical fibers. 2. The dust measuring apparatus according to claim 1, wherein dirt is determined based on the dust concentration values in the reverse connection state.   The first and second optical fibers are built in a flexible tube, the detection unit is attached to the front end of the flexible tube, and the dust concentration calculating means averages the dust concentration in a predetermined measurement time. The dust measuring device according to claim 1, wherein the dust measuring device is calculated. A light emitting means for emitting measurement light, an irradiation unit for irradiating the measurement light toward the measurement region, a light receiving unit for receiving the detection light from the measurement region, and the detection light from the light reception unit as a measurement signal A light receiving means for converting, a first optical fiber for guiding measurement light from the light emitting means to the irradiating section, a second optical fiber for guiding detected light from the light receiving section to the light receiving means, and A dust concentration calculating device comprising: a dust concentration calculating means for calculating a dust concentration based on a measurement signal from a light receiving means;
The first and second optical fibers are built in a flexible tube, the detection unit is attached to the front end of the flexible tube, and the dust concentration calculating means averages the dust concentration in a predetermined measurement time. A dust measuring device characterized by calculating. A light emitting means for emitting measurement light for measuring dust concentration in the measurement area, a light receiving means for converting detected light from the measurement area into a measurement signal, and a detection having an irradiation / light receiving section and a light receiving / irradiating section A dust measuring apparatus comprising: a unit unit; a first optical fiber connected to the irradiation / light receiving unit of the detection unit; and a second optical fiber connected to the light reception / irradiation unit of the detection unit. A dust measurement method for measuring the concentration of dust contained in a gas flow flowing through a measurement area using
The first optical fiber is connected to the light emitting means, the second optical fiber is connected to the light receiving means, and measurement light from the light emitting means is passed through the first optical fiber from the irradiation / light receiving section to the measurement area. And the detected light from the measurement area is received by the light receiving means from the light receiving / irradiating section through the second optical fiber, and the dust concentration in the positive connection state of the first and second optical fibers is received. Next, the second optical fiber is connected to the light emitting means, the second optical fiber is connected to the light receiving means, and the measurement light from the light emitting means is received through the second optical fiber. The first and second lights are irradiated from the irradiation unit toward the measurement area, and light to be detected from the measurement area is received from the irradiation / light reception unit through the first optical fiber to the light receiving unit. Dust measurement method characterized by calculating the dust concentration in the reverse connection state of Aiba. A light emitting means for emitting measurement light, an irradiation unit for irradiating the measurement light toward the measurement region, a light receiving unit for receiving the detection light from the measurement region, and the detection light from the light reception unit as a measurement signal A light receiving means for converting, a first optical fiber for guiding measurement light from the light emitting means to the irradiating section, a second optical fiber for guiding detected light from the light receiving section to the light receiving means, and A dust measurement method for measuring the concentration of dust flowing in a measurement area in a pipe using a dust measurement device comprising a dust concentration calculation means for calculating a dust concentration based on a measurement signal from a light receiving means,
From the state where the calculated value of the dust concentration calculating means has changed from outside the measurable range of the dust concentration to within the measurable range of the dust concentration, a predetermined amount of the irradiation unit and the light receiving unit are further inserted into the measurement area. A dust measuring method comprising positioning and measuring a dust concentration in the measurement area.

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