Particulate matter concentration detection device and intelligent extractor hood

Abstract

The utility model discloses an embodiment of a kind of particulate matter concentration detection device and intelligent range hood, particulate matter concentration detection device includes optical signal transmitting device and optical signal receiving device, the included angle between the emitting light center direction of optical signal transmitting device and the receiving light center direction of optical signal receiving device is preset angle, preset angle is 0 °-90 °, and the emitting light center direction of optical signal transmitting device and the receiving light center direction of optical signal receiving device are towards same side.The utility model by with the center direction of optical signal receiving device of optical signal transmitting device towards same side, and make the included angle between the emitting light center direction of optical signal transmitting device and the receiving light center direction of optical signal receiving device be acute angle, to form the effective detection area of limited range, solved the problem that the detection area of particulate matter concentration detection is too large or too small.

Description

Technical Field

[0001] This utility model relates to the field of range hood technology, and in particular to a particulate matter concentration detection device and an intelligent range hood. Background Technology

[0002] Current particulate matter concentration detection devices generally employ optical designs, utilizing the diffuse reflection of light signals by particles to detect particulate matter concentration. Common PM2.5 sensors on the market typically have an angle greater than 90° between the direction of the emitted light signal and the direction of the receiver, with the two directions intersecting at a single point. Particles must pass near this intersection to be detected. However, this approach has a small detection area, making it difficult to detect particulate matter concentration promptly and effectively in situations with uneven particulate matter distribution and unstable flow paths. For detection scenarios with large detection areas and uneven particulate matter concentration, existing technologies align the direction of the emitted light signal with the direction of the receiver, utilizing the reflection of light signals by particles to detect particulate matter concentration. This allows detection of a larger area in front of the sensor. While this approach addresses the shortcomings of the aforementioned PM2.5 sensors with a large detection area, the excessively large detection area makes it susceptible to environmental influences. For example, if the sensor is installed inside a machine, the detection signal will cover the machine's casing, and vibrations or contamination on the casing can affect the sensor's detection data.

[0003] Therefore, there is an urgent need for a particulate matter concentration detection device and a smart range hood with a moderate detection area, simple structure, strong anti-interference ability, and low cost to solve the above-mentioned technical problems. Utility Model Content

[0004] To solve this technical problem, the technical solution provided in this application is as follows: On the one hand, the present invention provides a particulate matter concentration detection device, which includes an optical signal emitting device and an optical signal receiving device. The angle between the center direction of the emitted light of the optical signal emitting device and the center direction of the received light of the optical signal receiving device is a preset angle, which is 0°-90°, and the center direction of the emitted light of the optical signal emitting device and the center direction of the received light of the optical signal receiving device are facing the same side.

[0005] In some possible implementations, the particulate matter concentration detection device further includes a protective structure, which includes a transmission protection structure and a reception protection structure; The transmission protection structure and the receiving protection structure are tubular structures; One end of the transmitting protection structure is sealed to the optical signal transmitting device, and the other end is a first opening; one end of the receiving protection structure is sealed to the optical signal receiving device, and the other end is a second opening.

[0006] In some possible implementations, the emission protection structure is provided with an emission barrier grid inside, and the optical signal boundary of the emitted light from the optical signal emitting device does not overlap with the emission barrier grid; The receiving protection structure has a receiving barrier grid inside, and the receivable boundary of the optical signal receiving device does not overlap with the receiving protection structure.

[0007] In some possible implementations, both the first opening and the second opening are obliquely cut, and the opening orientation of both the first opening and the second opening is consistent with the direction of the particle flow path.

[0008] In some possible implementations, the angle between the direction of the emitted light center of the optical signal emitting device and the direction of the particle flow path is less than 150°, and the angle between the direction of the received light center of the optical signal receiving device and the direction of the particle flow path is less than 150°.

[0009] In some possible implementations, the angle between the direction of the emitted light center of the optical signal transmitting device and the vertical direction is greater than 30°, and the angle between the direction of the received light center of the optical signal receiving device and the vertical direction is greater than 30°.

[0010] In some possible implementations, when liquid accumulation exists in the application environment of the particulate matter concentration detection device, the angle between the direction of the emitted light center of the optical signal emitting device and the vertical direction is greater than 90°, and the angle between the direction of the received light center of the optical signal receiving device and the vertical direction is greater than 90°.

[0011] In some possible implementations, the particulate matter concentration detection device is provided with a plurality of optical signal transmitting devices and optical signal receiving devices corresponding one-to-one with the plurality of optical signal transmitting devices.

[0012] In some possible implementations, the optical signal transmitting device includes a housing, a light-emitting device, and a collimating lens; The light-emitting device is disposed inside the housing, and the collimating lens is disposed on one side of the housing so that the emitted light emitted by the light-emitting device is emitted through the collimating lens.

[0013] On the other hand, this application also provides a smart range hood, the smart range hood having the above-mentioned particulate matter concentration detection device, and the smart range hood further including a fan and / or a blower; The particulate matter concentration detection device is installed in the negative pressure area formed by the fan and / or the blower driving particulate matter into the smart range hood.

[0014] This utility model discloses a particulate matter concentration detection device and a smart range hood. The particulate matter concentration detection device includes a light signal emitting device and a light signal receiving device. The angle between the center direction of the emitted light from the light emitting device and the center direction of the received light from the light receiving device is a preset angle, ranging from 0° to 90°, and the center directions of the emitted and received light from the light emitting and receiving devices are aligned to the same side. By aligning the center directions of the light emitting and receiving devices to the same side and making the angle between them an acute angle, this utility model forms a limited effective detection area, solving the problem of the detection area being too large or too small in particulate matter concentration detection. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a particulate matter concentration detection device provided in an embodiment of this utility model; Figure 2 This is a schematic diagram of the structure of a particulate matter concentration detection device for multi-area detection provided in an embodiment of this application; The corresponding reference numerals in the figure are: 1: Optical signal transmitting device; 11: Housing; 12: Light-emitting device; 13: Collimating lens; 2: Optical signal receiving device; 3: Protective structure; 31: Launch protective structure; 311: Launch barrier grid; 312: First opening; 32: Receiver protective structure; 321: Receiver barrier grid; 322: Second opening; 4: Fan or blower; AA: Center direction of the emitted light from the optical signal transmitting device; A-1: ​​Optical signal boundary 1; A-2: Optical signal boundary 2; BB: The direction of the receiving center of the optical signal receiving device; B-1: Receivable boundary 1; B-2: Receivable boundary 2. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0018] The term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of this application. In the description of this application, it should be understood that the terms "upper," "lower," "top," "bottom," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein.

[0019] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to an integer, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included. For example, a specified range from “1 to 10” should be considered to include any and all subranges between the minimum value 1 and the maximum value 10. Exemplary subranges of the range 1 to 10 include, but are not limited to, 1 to 6.1, 3.5 to 7.8, 5.5 to 10, etc.

[0020] Figure 1 This is a schematic diagram of the structure of a particulate matter concentration detection device provided in an embodiment of this utility model, as shown below. Figure 1As shown, the particulate matter concentration detection device includes a light signal emitting device 1 and a light signal receiving device 22. The angle between the center direction AA of the emitted light of the light emitting device and the center direction of the received light of the light receiving device 22 is a preset angle, which is 0°-90°. The center direction AA of the emitted light of the light emitting device and the center direction of the received light of the light receiving device 22 are on the same side.

[0021] For example, such as Figure 1 As shown, the particulate matter concentration detection device includes a light signal emitting device 1 and a light signal receiving device 22. The detection principle of the particulate matter concentration detection device is that the light signal emitted by the light signal emitting device 1 is reflected or diffusely reflected by the particulate matter to be detected to the light signal receiving device 2. The concentration of particulate matter is detected based on the magnitude and frequency of the signal received by the light signal receiving device 2.

[0022] The transmit light center direction AA of the optical signal transmitting device 1 refers to the center direction of the coverage area of ​​the emitted light emitted by the optical signal transmitting device 1, while the receive light center direction of the optical signal receiving device 22 refers to the center direction of the receivable area of ​​the optical signal receiving device 22. The transmit light center direction AA of the optical signal transmitting device and the receive light center direction BB of the optical signal receiving device are on the same side, meaning that the transmit light center direction AA of the optical signal transmitting device points in the same direction, for example... Figure 1 All the symbols shown point to the left. The left side here is just an example, and the actual setting should be determined according to the test requirements.

[0023] For example, to ensure the detection area is appropriately sized, the centers of the optical signal emitting device 1 and the optical signal receiving device 2 are set to face the same side. The angle between the center direction AA of the emitted light from the optical signal emitting device 1 and the center direction of the received light from the optical signal receiving device 22 is a preset angle, which is 0°-90°. Specifically, the emitted light from the optical signal emitting device 1 has optical signal boundaries, including optical signal boundary 1 and optical signal boundary 2. Figure 1 In the diagram, A-1 and A-2 are used as identifiers; the optical signal receiving device 2 has receivable boundaries, including receivable boundary 1 and receivable boundary 2, in... Figure 1In the diagram, B-1 and B-2 are used as identifiers. The boundaries of the optical signal and the receivable area have intersections within a set range. The envelope area formed by these intersections is the effective detection area of ​​the particulate matter concentration detection device (i.e., the envelope area formed by ABCD in the figure). The effective detection area is a limited range, which is related to the boundary of the optical signal emitted by the optical signal emitting device 1 and the boundary of the receivable area of ​​the optical signal receiving device 2. In practical applications, a suitable effective detection area can be designed according to the distribution of particulate matter by adjusting the direction of the emitted light center AA of the optical signal emitting device and the direction of the received light center of the optical signal receiving device 22. This ensures that the effective detection area can cover the particulate matter detection area or path over a large area, while also ensuring that the effective detection area avoids objects around the particulate matter detection area or path.

[0024] It should be noted that the aforementioned optical signal boundary refers to the boundary surface of the optical beam emitted by the optical signal transmitting device 1 outside the detection device, i.e. Figure 1 The optical signal boundary 1 and optical signal boundary 2 shown are labeled A-1 and A-2.

[0025] Optionally, the preset included angle is preferably 0°-45°.

[0026] Optionally, the particulate matter concentration detection device provided by this utility model needs to be set in an area with negative pressure, specifically, in a negative pressure area formed by the inhalation of particulate matter.

[0027] This invention sets the center direction AA of the emitted light of the optical signal transmitting device and the center direction BB of the received light of the optical signal receiving device to intersect at an acute angle, thereby forming a limited effective detection area. The size of the effective detection area can be adjusted according to specific needs, thus solving the problem of the detection area of ​​the particulate matter concentration detection device being too large or too small. This avoids the problem that the detection area is easily interfered with when it is too large, or that the detection area is sometimes inaccurate when it is too small.

[0028] In some possible implementations, the optical signal transmitting device 1 includes a housing, a light-emitting device 12, and a collimating lens 13; the light-emitting device 12 is disposed inside the housing, and the collimating lens 13 is disposed on one side of the housing, so that the emitted light emitted by the light-emitting device 12 is emitted through the collimating lens 13.

[0029] Please continue reading Figure 1The optical signal emitting device 1 includes a housing 11, a light-emitting device 12, and a collimating lens 13. The light-emitting device 12, which emits light, is disposed inside the housing. The collimating lens 13 is positioned in the direction of the emitted light from the light-emitting device 12, thereby transforming the light signal emitted by the light-emitting device 12 into a beam with a small diffusion angle, or even parallel light, after passing through the collimating lens 13. This not only ensures the intensity of the light signal but also facilitates the coverage of the particulate matter to be inspected area or path, and gives the light signal emitted by the optical signal emitting device 1 better directionality. At this point, the boundary of the light signal emitted by the optical signal emitting device 1 is the boundary surface of the beam outside the optical signal emitting device 1 after the light signal passes through the collimating lens 12.

[0030] Optionally, the optical signal receiving device 2 includes an optical receiving device, a receiving device housing, and a condenser lens (not shown in the figure). The condenser lens and the optical receiving device are disposed in the receiving device housing, and the condenser lens is disposed on the optical receiving path formed between the received light and the optical receiving device.

[0031] Optionally, to effectively receive light signals reflected or diffusely reflected from particulate matter, the receivable area boundary of the light signal receiving device 2 should be as large as possible. The receivable area boundary of the light signal receiving device 2 refers to the boundary of the condenser lens or light receiving device, connected to the boundary of the receiving device housing, forming the maximum boundary surface outside the detection device (including receivable boundary 1 and receivable boundary 2). Figure 1 (In the text, they are identified by B-1 and B-2). For example, the upper boundary of the receivable area of ​​the optical signal receiving device 2 is the line connecting the lowermost position of the condenser lens or optical receiving device to the uppermost position of the receiving device housing.

[0032] In some possible implementations, the particulate matter concentration detection device further includes a protective structure 3, which includes an emission protective structure 31 and a receiving protective structure 32; the emission protective structure 31 and the receiving protective structure 32 are tubular structures; one end of the emission protective structure 3 is sealed to the optical signal emitting device 1, and the other end is a first opening 312; one end of the receiving protective structure 32 is sealed to the optical signal receiving device 2, and the other end is a second opening 322.

[0033] In some possible implementations, both the first opening 312 and the second opening 322 are obliquely cut, and the opening orientation of both the first opening 312 and the second opening 322 is consistent with the direction of the particle flow path.

[0034] For example, please continue to see Figure 1 and Figure 2The optical signal transmitting device 1 and the optical signal receiving device 2 are each designed with a protective structure 3 in front. The protective structure 3 is divided into a transmitting protective structure 31 and a receiving protective structure 32.

[0035] The transmitting protection structure 31 is tubular, with one end sealed to the optical signal transmitting device 1 to form a blind tube, and the other end being a first opening 312. The optical signal can be transmitted to the detection area through the first opening 312 of the transmitting protection structure 31. The receiving protection structure 32 is tubular, with one end sealed to the optical signal receiving device 2 to form a blind tube, and the other end being a second opening 322. The optical signal can reach the receiving device through the opening of the receiving protection structure 32.

[0036] Furthermore, the first opening 312 and the second opening 322 can be designed as oblique cuts, with the oblique cuts designed according to the direction of the particle flow path. The opening orientation of both the first opening 312 and the second opening 322 is consistent with the direction of the particle flow path. Specifically, the projection of the position the particle passes through first in the flow path direction includes the projection of the position the particle passes through later in the flow path direction, that is, the position the particle passes through first protrudes more than the position the particle passes through later. The above principle applies to both the optical signal transmitting device 1 and the optical signal receiving device 2. In this way, it can be ensured that when the particle passes around the optical signal transmitting device 1 or the optical signal receiving device 2, the particle will be blocked outside the blind tube by the structure at the position it passes through first. For example, if the particle flow path direction is from bottom to top, then the oblique cuts of the first opening 312 and the second opening 322 are both projections in the vertical direction, with the projection at the lower position being larger than the projection at the upper position. When the particle flows, the outer wall structure at the lower position can block the particle from reaching the inner wall structure at the upper position, thereby preventing the particle from entering the interior of the blind tube. For example, when the flow path of the particles is from bottom to top, setting the opening direction of the oblique cut upwards can prevent the particles from directly entering the protective structure 3.

[0037] In this way, the shape of the oblique cut can be used to ensure that particulate matter cannot enter the protective device, and the principle that air cannot flow in the blind tube can be used to prevent particulate matter from contaminating the optical components of the detection device.

[0038] It should be noted that in the above scheme, the transmitting protection structure 31 and the receiving protection structure 32 are two separate structures that are not connected to each other and have no common parts (not shown in the figure).

[0039] Optional, for simplicity of structure, please refer to Figure 1The emission protection structure 31 and the receiving protection structure 32 can be integrated into one structure. Specifically, the emission protection structure 31 and the receiving protection structure 32 intersect and are fixedly connected. The first opening 312 and the second opening 322 are connected to form the opening of the light protection structure 3, and the opening of the light protection structure 3 is straight. In some possible embodiments, the opening of the light protection structure 3 is obliquely cut, and the opening direction of the light protection structure 3 is consistent with the direction of the particle flow path.

[0040] In some possible implementations, the emission protection structure 31 is provided with an emission barrier grid 311 inside, and the optical signal boundary of the emitted light of the optical signal emitting device 1 does not overlap with the emission barrier grid 311; the receiving protection structure 32 is provided with a receiving barrier grid 321 inside, and the receivable boundary of the optical signal receiving device 2 does not overlap with the receiving barrier grid 321.

[0041] For example, please continue to see Figure 1 The internal structure of the emission protection structure 31 is provided with an emission barrier grid 311, and the height of the emission barrier grid 311 is such that the boundary of the emitted light from the optical signal transmitting device 1 does not overlap with the emission barrier grid 311, meaning that the optical signal emitted by the optical signal transmitting device 1 will not be affected by the emission protection structure 31 and the emission barrier grid 311. In other words, the emitted optical signal will not illuminate the emission protection structure 31 and the receiving barrier grid 321.

[0042] Similarly, the receiving protection structure 32 has a receiving barrier grille 321 inside. The height of the receiving barrier grille 321 is such that the receivable boundary of the optical signal receiving device 2 does not overlap with the receiving barrier grille 321, meaning that the optical signal will not be affected by the receiving protection device and the receiving barrier grille 321 after entering the optical signal receiving device 2. That is, it will not illuminate the receiving protection device and the receiving barrier grille 321.

[0043] This invention provides barrier grilles in the transmitting protection structure 31 and the receiving protection structure 32, respectively. When particles accidentally enter the transmitting protection structure 31 and the receiving protection structure 32, they can be obstructed, reducing the probability of particles reaching the optical signal transmitting device 1 and the optical signal receiving device 2, and effectively preventing interference to the optical signal transmitting device 1 and the optical signal receiving device 2.

[0044] In some possible implementations, the angle between the emitted light center direction AA of the optical signal emitting device and the particle flow path direction is less than 150°, and the angle between the received light center direction BB of the optical signal receiving device and the particle flow path direction is less than 150°.

[0045] For example, to prevent particles from falling into the receiving protection structure 32 and the transmitting protection structure 31 due to inertia and to improve the anti-interference capability of the device, the angle between the transmission light center direction AA of the optical signal transmitting device and the particle flow path direction is set to be less than 150°, and the angle between the receiving light center direction BB of the optical signal receiving device and the particle flow path direction is less than 150°. When the angle is greater than 150°, since the particle flow path direction is opposite to the transmission light center direction AA of the optical signal transmitting device and the receiving light center direction BB of the optical signal receiving device, particles are more likely to rush into the blind tube due to inertia.

[0046] Preferably, the angle between the center direction AA of the emitted light of the optical signal emitting device and the direction of the particle flow path is 90°, and the angle between the center direction BB of the received light of the optical signal receiving device and the direction of the particle flow path is less than 90°.

[0047] In some possible implementations, the angle between the emitted light center direction AA of the optical signal transmitting device and the vertical direction is greater than 30°, and the angle between the received light center direction BB of the optical signal receiving device and the vertical direction is greater than 30°.

[0048] For example, the vertical direction refers to the direction perpendicular to the ground. The angle between the emission center direction AA of the optical signal transmitting device and the vertical direction is greater than 30°, and the angle between the receiving center direction BB of the optical signal receiving device and the vertical direction is greater than 30°. This can prevent particles from easily entering the blind tube due to inertia when the angle is too large, since the flow path of the particles is opposite to the emission center direction and the receiving center direction. This improves the anti-interference capability of the device.

[0049] Preferably, the vertical direction refers to the direction perpendicular to the ground. The angle between the emitted light center direction AA of the optical signal transmitting device and the vertical direction is set to 90°, and the angle between the received light center direction BB of the optical signal receiving device and the vertical direction is also set to 90°.

[0050] In some possible implementations, when liquid accumulation exists in the application environment of the particulate matter concentration detection device, the angle between the emitted light center direction AA of the optical signal emitting device and the vertical direction is greater than 90°, and the angle between the received light center direction BB of the optical signal receiving device and the vertical direction is greater than 90°.

[0051] In the application environment where liquid accumulation occurs, in order to prevent liquid from entering the protective structure 3, the optical signal transmitting device 1 or the optical signal receiving device 2 is configured such that the angle between the emitted light center direction AA of the optical signal transmitting device and the vertical direction is greater than 90°, and the angle between the received light center direction BB of the optical signal receiving device and the vertical direction is greater than 90°.

[0052] The effective detection area of ​​the particulate matter concentration detection device provided in this embodiment of the present invention is clearly defined, which provides an application basis for multi-area detection. Specifically, in some possible implementations, the particulate matter concentration detection device is provided with a plurality of optical signal transmitting devices 1 and optical signal receiving devices 2 corresponding one-to-one with the plurality of optical signal transmitting devices 1.

[0053] For example, Figure 2 This is a schematic diagram of a particulate matter concentration detection device for multi-area detection provided in this application embodiment. When applied to multi-area detection, only multiple sets of optical signal emitting devices 1 and optical signal receiving devices 2 are needed to form different effective detection areas, which can reduce costs. For example, since the stove below the range hood has left and right burners, the generated oil fume particles also enter the range hood from the left and right sides respectively, and the particle flow path inside the range hood has obvious left and right area distinctions. Two sets of optical signal emitting devices 1 and optical signal receiving devices 2 can be used to detect the oil fume particle concentration on the left and right sides respectively, avoiding the difficulty of a single detection device to simultaneously cover the left and right areas or the difference in detection sensitivity between the left and right sides, thus ensuring the accuracy of the detection data.

[0054] Specifically, such as Figure 2 As shown, the two sets of optical signal transmitting devices 1 and optical signal receiving devices 2 form effective detection areas by envelopes ABCD and EFGH, respectively.

[0055] On the other hand, this application provides an intelligent range hood, which includes the above-mentioned particulate matter concentration detection device and a fan and / or a blower; the particulate matter concentration detection device is disposed in the negative pressure area formed by the blower and / or the blower driving particulate matter into the intelligent range hood.

[0056] The above description is only an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A particulate matter concentration detection device, characterized in that, The particulate matter concentration detection device includes a light signal emitting device (1) and a light signal receiving device (2). The angle between the center direction (AA) of the emitted light of the light emitting device and the center direction (BB) of the received light of the light receiving device (2) is a preset angle, which is 0°-90°. The center direction (AA) of the emitted light of the light emitting device and the center direction (BB) of the received light of the light receiving device (2) are facing the same side.

2. The particulate matter concentration detection device according to claim 1, characterized in that, The particulate matter concentration detection device also includes a protective structure (3), which includes a transmission protective structure (31) and a receiving protective structure (32). The transmission protection structure (31) and the reception protection structure (32) are tubular structures; One end of the transmitting protection structure (31) is sealed to the optical signal transmitting device (1), and the other end is a first opening (312); one end of the receiving protection structure (32) is sealed to the optical signal receiving device (2), and the other end is a second opening (322).

3. The particulate matter concentration detection device according to claim 2, characterized in that, The emission protection structure (31) is provided with an emission barrier grid (311) inside, and the light signal boundary of the emitted light of the light signal emitting device (1) does not overlap with the emission barrier grid (311); The receiving protection structure (32) is provided with a receiving barrier grid (321) inside, and the receivable boundary of the optical signal receiving device (2) does not overlap with the receiving protection structure (32).

4. The particulate matter concentration detection device according to claim 2, characterized in that, Both the first opening (312) and the second opening (322) are oblique cuts, and the opening orientation of the first opening (312) and the second opening (322) is consistent with the flow path direction of the particles.

5. The particulate matter concentration detection device according to claim 1, characterized in that, The angle between the center direction (AA) of the emitted light of the optical signal transmitting device and the direction of the particle flow path is less than 150°, and the angle between the center direction of the received light of the optical signal receiving device (2) and the direction of the particle flow path is less than 150°.

6. The particulate matter concentration detection device according to claim 1, characterized in that, The angle between the center direction (AA) of the emitted light of the optical signal transmitting device and the vertical direction is greater than 30°, and the angle between the center direction of the received light of the optical signal receiving device (2) and the vertical direction is greater than 30°.

7. The particulate matter concentration detection device according to claim 6, characterized in that, When liquid accumulates in the application environment of the particulate matter concentration detection device, the angle between the emission center direction (AA) of the optical signal emitting device and the vertical direction is greater than 90°, and the angle between the receiving center direction of the optical signal receiving device (2) and the vertical direction is greater than 90°.

8. The particulate matter concentration detection device according to claim 1, characterized in that, The particulate matter concentration detection device is provided with a plurality of optical signal transmitting devices (1) and optical signal receiving devices (2) corresponding one-to-one with the plurality of optical signal transmitting devices (1).

9. The particulate matter concentration detection device according to claim 1, characterized in that, The optical signal transmitting device (1) includes a housing (11), a light-emitting device (12), and a collimating lens (13). The light-emitting device (12) is disposed inside the housing (11), and the collimating lens (13) is disposed on one side of the housing (11) so that the emitted light emitted by the light-emitting device (12) is emitted through the collimating lens (13).

10. A smart range hood, characterized in that, The intelligent range hood includes a particulate matter concentration detection device as described in any one of claims 1-9, and the intelligent range hood further includes a fan and / or a blower; The particulate matter concentration detection device is installed in the negative pressure area formed by the fan and / or the blower driving particulate matter into the smart range hood.

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