An optical system for dust measurement

Abstract

The present invention discloses an optical system for dust measurement, which includes a measurement cavity and a light-emitting component. A window piece (201), a measurement chamber (205), a reflection ring (206), a diaphragm (207), a light trap (208), a condenser lens (209), an optical fiber (210), and a reference light generating component (211) are arranged in the measurement cavity; the light-emitting component is installed on the outer side surface of the measurement cavity on one side of the window piece (201) through a connecting rod or a Teflon spacer. In the present invention, the scattered signal is reflected and converged to the end face of the optical fiber by the reflection ring to complete the acquisition of the effective signal. With the constraint of the diaphragm and the light trap, the forward scattering angle is small, and the signal of the annular gap can be collected. The detection accuracy is better than that of the conventional single-sided lens type forward scattering method, and the separation of the sampling gas path and the optical detection component is realized. The lens group will not be contaminated by dust, and the operation stability is good and the reliability is high.

Description

Technical Field

[0001] The present invention belongs to the technical field of environmental protection detection equipment, and particularly relates to an optical system for dust measurement. Background Art

[0002] In a modern industrial society, with the development of the world economy and the adjustment and transformation of the industrial structure, environmental pollution problems caused by pollution sources such as industrial boilers, power plant boilers, and industrial furnaces have become increasingly prominent, and various countries have conducted in-depth research and control on this. With the implementation of the "ultra-low emission" transformation in China, the soot emissions from domestic pollution sources present a complex working condition of low concentration and high humidity, and it is difficult to conduct on-line monitoring. The existing mainstream on-line monitoring products adopt a high-temperature extraction sampling and light scattering measurement scheme. After sampling, the high-humidity soot is subjected to high-temperature gasification pretreatment to eliminate the influence of liquid droplets on light scattering measurement. Finally, the laser forward scattering method is used to measure the particulate matter concentration. In some working conditions, the dust concentration is extremely low, and the detection accuracy of the measurement unit after high-temperature heating is low, making it difficult to achieve effective detection. In some other working conditions, the dust is accompanied by polluting components such as water vapor and sulfur dioxide, which are likely to cause pollution radiation or even blockage of the measurement chamber, resulting in poor reliability of the current on-line monitoring equipment for dust emissions from pollution sources. How to reliably and stably monitor the concentration value of composite dust has become a difficult problem. Summary of the Invention

[0003] The purpose of the present invention is to provide an optical system for dust measurement.

[0004] The technical solution of the present invention is as follows:

[0005] An optical system for dust measurement includes a measurement cavity and a light output component; a window piece, a measurement chamber, a reflection ring, a diaphragm, a light trap, a condenser lens, an optical fiber, and a reference light generating component are arranged in the measurement cavity; the window piece is arranged at the front end of the measurement chamber; the reflection ring, the diaphragm, and the light trap are arranged at the rear end of the measurement chamber, and the diaphragm adopts a double-ring structure. The reflection ring is inlaid and installed on the inner surface of the outer ring of the diaphragm, and the inner ring of the diaphragm is nested and installed on the outer surface of the light trap; the condenser lens and the optical fiber are sequentially arranged at the rear end of the light trap; the reference light generating component is arranged between the window piece and the measurement chamber; the central position inside the measurement chamber is an effective measurement area, and an intake air passage and an exhaust air passage are respectively arranged at the upper and lower side positions of the measurement chamber; the light output component is installed on the outer side surface of the measurement cavity on the side where the window piece is arranged through a connecting rod or a Teflon spacer.

[0006] In the present invention, the scattered signal is reflected and converged onto the end face of the optical fiber by the reflection ring to complete the acquisition of the effective signal. Constrained by the diaphragm and the optical trap, the forward scattering angle is small, the signal of the annular gap can be collected, and the detection accuracy is high, which is superior to the conventional unilateral lens type forward scattering method. Moreover, the separation of the sampling gas path and the optical detection component is realized, the lens group will not be contaminated by dust, and the operation stability is good and the reliability is high. The reflection ring, the optical trap, the condenser lens, the optical fiber and the diaphragm of the present invention together constitute the optical detection component of the present invention, and the installation of the reflection ring and the optical trap is restricted by the diaphragm, effectively improving the measurement accuracy.

[0007] The present invention further illustrates that the light-emitting component includes a first laser, a collimating lens holder and a fixed seat; a collimating lens is installed on the collimating lens holder for collimating the laser.

[0008] The present invention further illustrates that a second laser is further provided on the fixed seat, and the emitted reference beam hits the reference light generating component, and the generated reference light is reflected by the reflection ring to the end face of the optical fiber for detection. The intensity of the reference light can be modulated by adjusting the beam size of this path of laser.

[0009] The present invention further illustrates that the reflection ring is a glass ring structure, and its annular outer surface is aluminized to realize the reflection of the effective optical signal.

[0010] The present invention further illustrates that the optical fiber is the light signal receiving end, and a glass optical fiber is adopted to support the detection of the light signal under high temperature conditions.

[0011] The present invention further illustrates that there is an annular structure between the optical trap and the diaphragm, and sheath gas is introduced into this annular structure, and the protection effect is good.

[0012] The present invention further illustrates that the reference light generating component is a frosted glass structure, which receives the reference beam to generate uniform and stable diffuse reflection light as an effective range calibration signal.

[0013] The present invention further illustrates that the optical system can converge the annular forward scattering signal with an angle less than 20 degrees through the constraints of the diaphragm and the optical trap.

[0014] Advantages of the present invention:

[0015] 1. The optical detection component and the window piece of the present invention are distributed on both sides of the effective measurement area, and are protected by annular sheath gas, will not be contaminated by dust, and have high operation reliability.

[0016] 2. The present invention can converge the annular forward scattering signal with an angle less than 20 degrees through the constraints of the diaphragm and the optical trap, and has high optical detection accuracy.

[0017] 3. The present invention uses a ground glass structure to receive a reference beam and generate uniform and stable diffuse reflection light as an effective range calibration signal, thereby achieving full optical path calibration. Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of an optical system for dust measurement according to an embodiment of the present invention.

[0019] In the figure: 101, the first laser; 102, the collimating mirror base; 103, the fixed base; 201, the window piece; 202, the intake air path; 203, the exhaust air path; 204, the effective measurement area; 205, the measurement chamber; 206, the reflection ring; 207, the diaphragm; 208, the optical trap; 209, the condenser lens; 210, the optical fiber; 211, the reference light generating component; 301, the emission optical path; 302, the scattering optical path; 303, the reference beam. Detailed Embodiment

[0020] The present invention will be further described below with reference to the drawings. Embodiment

[0021] As Figure 1 shown, an optical system for dust measurement includes a measurement cavity and a light emitting component; a window piece 201, a measurement chamber 205, a reflection ring 206, a diaphragm 207, an optical trap 208, a condenser lens 209, an optical fiber 210, and a reference light generating component 211 are provided in the measurement cavity; the window piece 201 is arranged at the front end of the measurement chamber 205; the reflection ring 206, the diaphragm 207, and the optical trap 208 are arranged at the rear end of the measurement chamber 205, and the diaphragm 207 adopts a double-ring structure, the reflection ring 206 is inlaid on the inner surface of the outer ring of the diaphragm 207, and the inner ring of the diaphragm 207 is nested on the outer surface of the optical trap 208; the condenser lens 209 and the optical fiber 210 are sequentially arranged at the rear end of the optical trap 208; the reference light generating component 211 is arranged between the window piece 201 and the measurement chamber 205; the central position inside the measurement chamber 205 is the effective measurement area 204, and an intake air path 202 and an exhaust air path 203 are respectively arranged at the upper and lower side positions of the measurement chamber 205; the light emitting component is installed on the outer side of the measurement cavity on the side where the window piece 201 is arranged through a connecting rod or a Teflon spacer.

[0022] This embodiment further illustrates that the light emitting component includes a first laser 101, a collimating mirror base 102, and a fixed base 103; a collimating lens is installed on the collimating mirror base 102 to collimate the laser.

[0023] This embodiment further illustrates that a second laser is also provided on the fixed seat 103, which emits a reference beam 303 that hits the reference light generating component 211. The generated reference light is reflected by the reflection ring 206 to the fiber end face for detection. The intensity of the reference light can be modulated by adjusting the beam size of this path of laser light.

[0024] This embodiment further illustrates that the reflection ring 206 is of a glass ring structure, and its outer annular surface is aluminized to achieve the reflection of effective optical signals.

[0025] This embodiment further illustrates that the optical fiber is an optical signal receiving end, and a glass optical fiber is used to support the detection of optical signals under high-temperature conditions.

[0026] This embodiment further illustrates that there is an annular structure between the optical trap 208 and the aperture 207, and sheath gas is introduced into this annular structure, which has a good protection effect.

[0027] This embodiment further illustrates that the reference light generating component 211 is of a frosted glass structure, which receives the reference beam to generate uniform and stable diffuse reflection light as an effective range calibration signal.

[0028] This embodiment further illustrates that through the constraints of the aperture and the optical trap, the optical system can converge the annular forward scattering signal with an angle less than 20 degrees.

[0029] Obviously, the above embodiments are merely examples for clearly illustrating the present invention and are not limitations on the implementation of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description; it is not necessary and impossible to enumerate all the implementation manners here; and the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. An optical system for dust measurement, comprising a measurement cavity and a light output component, characterized in that: A window sheet (201), a measurement chamber (205), a reflection ring (206), a diaphragm (207), a light trap (208), a condenser lens (209), an optical fiber (210), and a reference light generating component (211) are provided in the measurement cavity; The window sheet (201) is arranged at the front end of the measurement chamber (205); the reflection ring (206), the diaphragm (207), and the light trap (208) are arranged at the rear end of the measurement chamber (205), and the diaphragm (207) adopts a double-ring structure. The reflection ring (206) is inlaid and installed on the inner surface of the outer ring of the diaphragm (207), and the inner ring of the diaphragm (207) is nested and installed on the outer surface of the light trap (208); the condenser lens (209) and the optical fiber (210) are sequentially arranged at the rear end of the light trap (208); the reference light generating component (211) is arranged between the window sheet (201) and the measurement chamber (205); The central position inside the measurement chamber (205) is an effective measurement area (204), and an intake air passage (202) and an exhaust air passage (203) are respectively arranged at the upper and lower side positions of the measurement chamber (205); The light output component is installed on the outer side of the measurement cavity on the side where the window sheet (201) is provided through a connecting rod or a Teflon spacer.

2. The optical system for dust measurement according to claim 1, wherein: The light output component includes a first laser (101), a collimating mirror base (102), and a fixing base (103); a collimating lens is installed on the collimating mirror base (102) to collimate the laser.

3. The optical system for dust measurement according to claim 2, characterized in that: A second laser is further provided on the fixing base (103), and a reference light beam (303) is emitted and hits the reference light generating component (211). The generated reference light is reflected by the reflection ring (206) to the end face of the optical fiber for detection. The intensity of the reference light can be modulated by adjusting the beam size of this path of laser.

4. The optical system for dust measurement according to claim 1, characterized in that: The reflection ring (206) is a glass ring structure, and its annular outer surface is aluminized to reflect effective optical signals.

5. The optical system for dust measurement according to claim 1, characterized in that: The optical fiber is a light signal receiving end, and a glass optical fiber is adopted to support the detection of optical signals under high-temperature conditions.

6. The optical system for dust measurement according to claim 1, characterized in that: There is an annular structure between the light trap (208) and the diaphragm (207), and sheath gas is introduced into this annular structure, providing good protection.

7. The optical system for dust measurement according to claim 1, characterized in that: the reference light generating component (211) is a frosted glass structure, which receives the reference light beam to generate uniform and stable diffuse reflection light as an effective range calibration signal.

8. The optical system for dust measurement according to claim 1, characterized in that: the optical system can converge the annular forward scattering signal with an angle less than 20 degrees through the constraints of the diaphragm and the light trap.

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