A particle monitor

Abstract

The present invention discloses a particle monitor. The particle monitor comprises: a light source module, which generates light; a spectroscopic module, which divides the light emitted by the light source module into calibration light and measurement light; a light blocking mechanism, which blocks the calibration light or the measurement light; a scattering structure, wherein the light emitted by the spectroscopic module passes through a window piece, a first aperture and a second aperture of the scattering structure in sequence; a light receiving module, which receives the light emitted by the scattering structure; and a detector, which determines the light energy received by the light receiving module. The particle monitor of the present invention has a pollution self-diagnosis function.

Description

Technical Field

[0001] The invention belongs to the field of environmental monitoring, and in particular relates to a particle monitoring instrument. Background Art

[0002] With the increasingly stringent environmental laws and regulations, as well as the advancement and development of dust removal technology, the emission concentration of particulate matter from organized pollution sources is getting lower and lower. There are many newly launched coal-fired boilers, and the average concentration of particulate matter emissions is even lower than 3mg / m 3 , and has the characteristics of high temperature and high humidity. This puts higher requirements on the instrument's detection limit, sensitivity, repeatability, and stray light suppression.

[0003] Since the flue gas emitted by the equipment has the characteristics of high temperature and high humidity, it is easy to form water mist on the lens and absorb dust. When dust and water mist adhere to the lens, the transmittance of the lens will be reduced, affecting the normal operation of the instrument. The current instrument only measures the flue gas particles, but does not have the function of regularly testing the pollution degree of the optical system, especially the function of evaluating the pollution degree of the optical components in the particle measurement room. Summary of the invention

[0004] In order to solve the above problems, the present invention proposes a particle monitor, which is provided with a light path pollution degree self-diagnosis function to achieve the measurement of the light path pollution value.

[0005] The present invention provides a particle monitor, comprising: a light source module, which generates light; a spectroscopic module, which divides the light emitted by the light source module into calibration light and measurement light; a light blocking mechanism, which blocks the calibration light or the measurement light; a scattering structure, wherein the light emitted by the spectroscopic module passes through a window piece, a first aperture and a second aperture of the scattering structure in sequence; a light receiving module, which receives the light emitted by the scattering structure; and a detector, which determines the light energy received by the light receiving module.

[0006] As an optional solution of the present invention, the particle monitor also includes a shell, which is a cavity structure. The light source module, the light splitting module, and the light blocking mechanism are located in the cavity of the shell. The scattering structure is fixed on the shell, and the light receiving module is connected to the scattering structure.

[0007] As an optional solution of the present invention, the scattering structure includes a probe rod, which is tubular, and a window piece mounting seat with a window piece installed, a first aperture mounting seat with a first aperture installed, a second aperture mounting seat with a second aperture installed, and a light receiving module mounting seat are arranged in sequence from one end to the other end of the probe rod, and a light through hole is provided on the light receiving module mounting seat, and the light receiving module is connected to the light receiving module mounting seat, and the light through hole of the light receiving module mounting seat is opposite to the light inlet hole of the light receiving module.

[0008] As an optional solution of the present invention, the particle monitor also includes a light trap cover, which includes a cover body and a light trap module, and the light trap module is located on the inner wall of the cover body; the cover body and the light receiving module mounting seat form a closed cavity, and the light receiving module is located in the cavity; the light trap module absorbs unscattered light in the measurement light.

[0009] As an optional solution of the present invention, the light trap module includes a convex spherical member with an inclined end and a trap tube with an internal thread, and the convex spherical member is located inside the trap tube.

[0010] As an optional solution of the present invention, the convex spherical surface member and the well tube are both subjected to blackening treatment.

[0011] As an optional solution of the present invention, the particle monitor also includes a flange, which is cylindrical and fixed to the bottom of the housing; the scattering structure passes through the flange, and the outer wall of the second aperture mounting seat cooperates with the inner wall of the flange; and an air inlet is provided on the side wall of the flange.

[0012] As an optional solution of the present invention, an air inlet is provided on the probe rod of the scattering structure, and the air inlet of the probe rod is communicated with the air inlet of the flange.

[0013] As an optional solution of the present invention, an observation port is provided on the side wall of the flange.

[0014] As an optional solution of the present invention, the detector is located in the cavity of the shell.

[0015] The particle monitor of the present invention divides the light emitted by the light source module into calibration light and measurement light. The calibration light is used to detect the degree of contamination of the light path. The measurement light irradiates the particles and causes scattering. The light receiving module receives the scattered light of the measurement light, which can be used to calculate the particle concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the particle monitor of the present invention.

[0017] Figure 2 It is a structural schematic diagram of the particle monitor of the present invention.

[0018] Figure 3 is a schematic diagram of a light source module of the present invention.

[0019] Figure 4 It is a schematic diagram of the light splitting module of the present invention.

[0020] Figure 5 It is a schematic diagram of the light blocking mechanism of the present invention.

[0021] Figure 6Schematic diagram of the scattering structure of the present invention.

[0022] Figure 7 It is a schematic diagram of the light receiving module of the present invention.

[0023] Figure 8 Schematic diagram of the light trap cover of the present invention.

[0024] Fig. 9 It is a schematic diagram of the flange of the present invention.

[0025] Fig.10 It is a schematic diagram of the purge gas path of the present invention.

[0026] Fig.11 Schematic diagram of the sample gas port of the present invention. DETAILED DESCRIPTION

[0027] The following is a more detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings and examples, so that the scheme of the present invention and its advantages in various aspects can be better understood. However, the specific embodiments and examples described below are only for the purpose of illustration, rather than for limiting the present invention.

[0028] The "connection" described in the present invention should be understood in a broad sense, unless otherwise clearly specified or limited, and can be directly connected or connected through an intermediate medium. In the description of the present invention, it should be understood that the directions or positional relationships indicated by "upper", "lower", "front", "back", "left", "right", "top", "bottom", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0029] like Figure 1 and 2 As shown, the particle monitor of the embodiment of the present invention divides the light generated by the light source into calibration light and measurement light. When performing self-test or calibration, the measurement light is blocked and only the calibration light is emitted. According to the energy of the calibration light received by the detector, the transmittance of the light path or the linearity of the instrument can be measured. When measuring the sample gas, the calibration light is blocked and only the measurement light is emitted. The measurement light irradiates the particles in the sample gas and is scattered, and the detector determines the energy of the scattered light. The ratio of the energy of the scattered light to the energy of the calibration light is positively correlated with the concentration of the particulate matter.

[0030] The particle monitor includes: a light source module 100 , a light splitting module 200 , a light blocking mechanism 300 , a scattering structure 400 , a light receiving module 500 and a detector 600 .

[0031] like Figure 3As shown, the light source module 100 is used to generate parallel light. The light source module 100 includes a laser board 101, which is a circuit board of the light source module. A laser diode 102 is mounted on the laser board 101 through a base 103, and the laser diode 102 emits light after being powered on. A collimator 104 is arranged below the laser diode 102 through a mounting tube 105, and the light emitted by the laser diode 102 passes through the collimator 104 to form a parallel beam and is emitted.

[0032] like Figure 4 As shown, the light splitting module 200 includes a light splitting prism mounting plate 201, and the light splitting prism mounting plate 201 can be made of stainless steel for easy installation and fixation. The light splitting prism 202 is mounted on the light splitting prism mounting plate 201. The light emitted by the light source module 100 is irradiated on the light splitting prism 202 and is divided into two parallel light beams, one as a calibration light beam and the other as a measurement light beam.

[0033] A plurality of studs 203 are provided on the beam splitter prism mounting plate 201, and elastic members (not shown in the figure, such as springs) are sleeved on the studs 203. Nuts 204 are installed on the studs 203. Optionally, the laser board 101 is sleeved on the studs 203, the elastic members support the laser board 101, and the nuts 204 are pressed on the laser board 101. The angle of light emitted by the light source module 100 can be adjusted by adjusting the nuts 204.

[0034] like Figure 5 As shown, the light blocking mechanism 300 is fixed on the beam splitter prism mounting plate 201. The light blocking mechanism 300 includes an electromagnet 301, the iron core of the electromagnet 301 serves as a swing arm 302, and a light blocking plate 303 is installed on the swing arm 302. A permanent magnet (not shown in the figure) is provided below the electromagnet 301. When the electromagnet 301 is not energized, the permanent magnet attracts the swing arm 302 to swing downward. After the electromagnet 301 is energized, the magnetism of the swing arm 302 is the same as that of the permanent magnet, and the repulsive force of the like magnetic poles causes the swing arm 302 to swing upward. The swing of the swing arm 302 drives the light blocking plate 303 to move, and the light blocking plate 303 can block the calibration light or the measurement light, so that only one beam of light is emitted by the beam splitter module 200.

[0035] The light emitted from the spectroscopic module 200 irradiates the scattering structure 400 , on which a window sheet, a first aperture and a second aperture are provided. The light emitted from the spectroscopic module 200 passes through the window sheet, the first aperture and the second aperture once and then emits from the scattering structure 400 .

[0036] like Figure 6As shown, the scattering structure 400 of this embodiment includes a probe rod 401, which is the main body of the scattering structure 400 and is a tubular structure with a through hole inside. A fixing plate 402 is provided at the top of the probe rod 401 for fixing the scattering structure 400. A window plate mounting seat 403 is provided on the fixing plate 402, and a window plate 407 is mounted on the window plate mounting seat 403. The window plate mounting seat 403 is arranged parallel to the probe rod 401. The window plate 407 can protect the light source module 100 and the light splitting module 200. Below the window plate mounting seat 403 is a first aperture mounting seat 404, and a first aperture 408 is mounted on the first aperture mounting seat 404. Below the first aperture mounting seat 404 is a second aperture mounting seat 405, and a second aperture 409 is mounted on the second aperture mounting seat 405. The bottom end of the probe rod 401 is a light receiving module mounting seat 406. A light hole 410 is provided on the light receiving module mounting seat 406, and the light hole 410 is opposite to the second aperture 409, and the light emitted by the second aperture 409 passes through the light hole 410. The first aperture 408 and the second aperture 409 play a role in eliminating stray light.

[0037] The light receiving module 500 is mounted on the light receiving module mounting 406 , and the light emitted by the scattering structure 400 is received by the light receiving module 500 .

[0038] like Figure 7 As shown, the light receiving module 500 of this embodiment includes a mirror base 501, and a plano-convex lens 502 is provided at the light inlet at the top of the mirror base 501. The light inlet of the light receiving module 500 is opposite to the light through hole 410 of the light receiving module mounting base, so that the light emitted by the scattering structure 400 enters the light receiving module 500.

[0039] A reflector 504 is fixed on the side wall of the mirror base 501 through a reflector pressing plate 503. The calibration light passes through the scattering structure 400 and enters the light receiving module 500. The calibration light passes through the plano-convex lens 502 and the reflector 504 and enters the optical fiber connected to the light receiving module 500.

[0040] After the measuring light passes through the scattering structure 400 , the scattered light enters the light receiving module 500 , and then passes through the plano-convex lens 502 and enters the optical fiber connected to the light receiving module 500 .

[0041] The mirror base 501 is connected to an adapter plate 505 , and the adapter plate 505 is used to be fixed to the light receiving module mounting base 406 .

[0042] The detector 600 is connected to the light receiving module 500 via an optical fiber, and the detector 600 determines the light energy received by the light receiving module 500.

[0043] When the particle monitor of this embodiment is calibrated, the measuring light is blocked by the light blocking mechanism 300, and only the calibration light is emitted from the spectroscopic module 200. The calibration light passes through the window 407, the first aperture 408, the second aperture 409, the light hole 410, the plano-convex lens 502, and the reflector 504 on the scattering structure, and reaches the end face of the optical fiber, and the optical fiber guides the light energy into the detector 600. The detector 600 determines that the energy of the received calibration light is E1.

[0044] E1 will gradually decrease due to the aging of the device and the pollution of the lens. The initial value of E1 is taken as E0, that is, the energy of the calibration light when the particle monitor is not polluted and not aged is E0. The cleanliness of the light path can be measured by the transmittance:

[0045]

[0046] When the degree of contamination of the optical element of the particle monitor exceeds a certain limit, the transmittance decreases to a preset value (such as less than 0.7), and the particle monitor can issue an early warning to remind the staff. The particle monitor of this embodiment has a self-diagnosis function of optical path contamination.

[0047] When the particle monitor detects the sample gas, the calibration light is blocked by the light blocking mechanism 300, and only the measurement light is emitted from the spectroscopic module 200. The measurement light passes through the window 407, the first aperture 408, and the second aperture 409 on the scattering structure and is scattered by the particles in the sample gas. The scattered light passes through the plano-convex lens 502 and reaches the end face of the optical fiber, and the optical fiber guides the light energy into the detector 600. The detector 600 determines that the energy of the received scattered light is E2.

[0048] The ratio of the energy of the scattered light (E2) to the energy of the calibration light (E1) is positively correlated to the concentration of the particles, and the particle concentration value can be obtained by calibration using standard methods.

[0049]

[0050] Because the energy intensity of the calibration light has already included the influence of light path pollution, the particle concentration obtained by the particle monitor of this embodiment eliminates the influence of light path pollution.

[0051] Alternatively, if Figure 2 As shown, the particle monitor also includes a housing 800, which is a cavity structure and can be made of aluminum. The light source module 100, the light splitting module 200, and the light blocking mechanism 300 are all located in the cavity of the housing 800. The fixing plate 402 of the scattering structure is fixed in the cavity of the housing 800 through the fixing plate 801, and the other parts of the scattering structure 400 extend out of the housing 800.

[0052] like Figure 2 and Figure 8 As shown, the particle monitor also includes a light trap cover 700. The light trap cover 700 includes a cover body 701 and a light trap module. The cover body 701 and the light receiving module mounting seat 406 form a closed cavity, and the light receiving module 500 is located in the cavity. The light trap module is located on the inner wall of the cover body 701. The light trap module absorbs the unscattered light in the measurement light to prevent the light from being scattered in the cavity of the cover body 701 and interfering with the performance of the instrument. The cover body 701 protects the light receiving module 500 and the light trap module.

[0053] The light trap module includes a convex spherical member 702 and a trap tube 703. The trap tube 703 is cylindrical, and the convex spherical member 702 is located inside the trap tube 703. The end face of the convex spherical member 702 is a convex spherical surface, which can reflect light onto the trap tube 703. The light trap module can annihilate light to prevent the unscattered light from affecting the monitoring results.

[0054] Optionally, the convex spherical member 702 and the trap tube 703 are both made of aluminum and are blackened to facilitate annihilation of light.

[0055] like Fig. 9 As shown, the particle monitor further includes a flange 900. The flange 900 is fixed to the bottom of the housing 800. The flange 900 includes a body 901, which is cylindrical, and the scattering structure 400 passes through the flange 900, and the outer wall of the second aperture mounting seat 405 matches the inner wall of the flange 900. The body 901, the second aperture mounting seat 405 and the fixing plate 402 of the scattering structure form a closed space.

[0056] An air inlet 902 is provided on the side wall of the flange, and the air inlet 902 is connected to a clean air (zero air) source through a connector 903. The clean air is introduced into the cavity of the flange 900 to purge the optical device in the flange to prevent the optical device from being contaminated.

[0057] An air inlet 411 is provided on the probe rod of the scattering structure, and the air inlet 411 of the probe rod is connected to the air inlet 902 of the flange. Clean air can enter the probe rod 401 and enter the cavity of the light trap cover 700 through the probe rod 401 to purge the light receiving module 500.

[0058] like Fig.10 The purge gas path shown in the figure enters from the air inlet 902. One path of the purge gas purges the window plate 407, the first aperture 408, and the second aperture 409, and flows out from the light outlet hole of the second aperture 409. The other path enters the cavity of the light trap cover 700 through the air inlet 411 of the probe rod, and flows out from the light hole 410 provided on the light receiving module mounting seat 406.

[0059] like Fig. 9As shown, an observation port 904 is provided on the side wall of the flange. The observation port 904 is located opposite to the window sheet 407. Through the observation port 904, it is possible to observe whether there is dust on the window sheet 407 and clean the window sheet 407 in time. A detachable sealing cover 905 is installed at the observation port 904. The sealing cover 905 is provided to facilitate cleaning in the observation port 904. The connecting portion 906 is used for fixed connection with the housing 800.

[0060] Optionally, the detector 600 is located in the cavity of the housing 800 , and the optical fiber connecting the light receiving module 500 and the detector 600 passes through the probe rod 401 .

[0061] like Fig.11 As shown, the position of the sample gas port is at A. During measurement, the sample gas (measured gas) is introduced through the sample gas port, and during calibration, the clean gas is introduced through the sample gas port.

[0062] It should be noted that the various embodiments described above with reference to the accompanying drawings are only used to illustrate the present invention rather than to limit the scope of the present invention. Those skilled in the art should understand that any modification or equivalent substitution of the present invention without departing from the spirit and scope of the present invention should be included within the scope of the present invention. In addition, unless otherwise indicated by the context, words appearing in the singular include the plural form, and vice versa. In addition, unless otherwise specified, all or part of any embodiment may be used in combination with all or part of any other embodiment.

Claims

1. A particle monitor, characterized in that: include: A light source module, wherein the light source module generates light; A light splitting module, which divides the light emitted by the light source module into calibration light and measurement light; A light blocking mechanism, blocking the calibration light or the measurement light, so that only one beam of light is emitted from the light splitting module; A scattering structure, wherein the light emitted by the light splitting module passes through the window piece, the first aperture and the second aperture of the scattering structure in sequence; A light receiving module, receiving the light emitted by the scattering structure; A detector, connected to the light receiving module via an optical fiber, and used to determine the light energy received by the light receiving module; The flange has a side wall provided with an air inlet, and the gas introduced into the air inlet is used to purge at least the light receiving module; The housing is a cavity structure, the light source module, the light splitting module, and the light blocking mechanism are located in the cavity of the housing, the scattering structure is fixed on the housing, and the light receiving module is connected to the scattering structure; Wherein, the scattering structure includes a probe rod, the probe rod is tubular, and a window piece mounting seat with a window piece mounted thereon, a first aperture mounting seat with a first aperture mounted thereon, a second aperture mounting seat with a second aperture mounted thereon, and a light receiving module mounting seat are sequentially arranged from one end of the probe rod to the other end, a light through hole is arranged on the light receiving module mounting seat, the light receiving module is connected to the light receiving module mounting seat, and the light through hole of the light receiving module mounting seat is opposite to the light inlet hole of the light receiving module; The particle monitor further comprises a light trap cover, which comprises a cover body and a light trap module, wherein the light trap module is located on the inner side wall of the cover body; the cover body and the light receiving module mounting seat form a closed cavity, wherein the light receiving module is located in the cavity; the light trap module absorbs unscattered light in the measurement light; An air inlet is provided on the probe rod of the scattering structure, and the air inlet of the probe rod is connected to the air inlet of the flange; After the purge gas enters from the air inlet of the flange, one path of the purge gas purges the window plate, the first aperture, and the second aperture, and flows out from the light outlet hole of the second aperture; the other path of the purge gas enters the cavity of the light trap cover through the air inlet of the probe rod, and flows out from the light hole on the light receiving module mounting seat.

2. The particle monitor according to claim 1, characterized in that: The light trap module comprises a convex spherical member with an inclined end and a trap cylinder with an internal thread, wherein the convex spherical member is located inside the trap cylinder.

3. The particle monitor according to claim 2, characterized in that: The convex spherical surface part and the well tube are both subjected to blackening treatment.

4. The particle monitor according to claim 1, characterized in that: The flange is cylindrical and fixed to the bottom of the shell; The scattering structure passes through the flange, and the outer wall of the second aperture mounting seat matches the inner wall of the flange.

5. The particle monitor according to claim 4, characterized in that: An observation port is arranged on the side wall of the flange.

6. The particle monitor according to claim 1, characterized in that: The detector is located in the cavity of the housing.

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