Particulate matter concentration detection device

Abstract

The invention relates to the technical field of detection devices, and discloses a particulate matter concentration detection device which comprises a shell provided with an inner cavity, and an air inlet and an air outlet are formed in the shell; the inner cavity is divided into a first area and a second area which are opposite to each other, and the second area is provided with a flow channel isolated from the first area; the flow channel communicates with the air inlet and the air outlet; the detection element is arranged in the second area and is used for detecting the concentration of particulate matters in the flow channel; the fan is arranged in the flow channel and is used for driving the oil smoke airflow in the flow channel to flow; and the circuit board is arranged in the first area and is electrically connected with the detection element and / or the fan. According to the particulate matter concentration detection device, the flow channel is designed to be the independent part isolated from the first area, so that oil fume airflow is prevented from being in direct contact with electronic elements such as a circuit board, the risk of short circuit of the electronic elements caused by oil fume or water vapor deposition is reduced, and the safety and stability of the device are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of detection devices, and in particular to a particle concentration detection device. Background Art

[0002] With the rapid development of modern technology, smart home has become an important part of people's daily life, greatly improving the convenience and comfort of life. In the kitchen, the core area of ​​family life, the intelligent upgrade of home appliances is particularly important. As the core electrical equipment in the kitchen, the improvement of the intelligent level of range hoods is of great significance to improving the kitchen environment and protecting the health of users.

[0003] Traditional range hoods mostly rely on manual adjustment or preset programs to control the smoking mode, which is difficult to dynamically adjust according to the actual air quality in the kitchen. This may not only lead to poor smoking effect, but also cause energy waste. Therefore, it is particularly important to develop smart range hoods that can automatically adjust the smoking mode according to the kitchen air quality.

[0004] In order to achieve this goal, there are methods in the prior art that attempt to identify the kitchen air quality by detecting the concentration of inhalable particulate matter in the kitchen and automatically adjust the smoking mode accordingly. This method uses a particle concentration detection device to monitor the concentration of particulate matter in the kitchen air in real time, thereby achieving precise control of the smoking effect.

[0005] However, the existing technology still has many deficiencies in particle detection. Specifically, when oil smoke, water vapor and other particles pass through the particle concentration detection device, they often directly contact the electronic components inside the device. Due to the particularity of oil smoke, water vapor and other substances in the kitchen environment, long-term direct contact with electronic components will cause problems such as short circuit and damage of electronic components, which not only affects the normal operation of the range hood, but also may cause safety hazards and reduce the reliability and service life of the product. Summary of the invention

[0006] Based on the technical problem in the prior art that the oil fume airflow directly contacts the internal electronic components, causing the electronic components to be easily short-circuited and damaged, the present invention provides a particle concentration detection device. By setting the flow channel as an independent part isolated from the installation area, the oil fume airflow is prevented from directly contacting the electronic components such as the circuit board, reducing the risk of short circuit of the electronic components due to the deposition of oil fume or water vapor, thereby improving the safety and stability of the device.

[0007] The present invention provides a particle concentration detection device, comprising: A shell having an internal cavity, wherein an air inlet and an air outlet are provided on the shell; the internal cavity is divided into a first area and a second area opposite to each other, wherein the second area is provided with a flow channel isolated from the first area; the flow channel communicates with the air inlet and the air outlet to guide the oil smoke flow to pass through; a detection element disposed in the second region and configured to detect a concentration of particles in the flow channel; A fan, disposed in the flow channel, for driving the oil smoke airflow in the flow channel; The circuit board is arranged in the first area and is electrically connected to the detection element and / or the fan.

[0008] In some embodiments, the flow channel includes, in sequence: An air inlet section, the air inlet section being in communication with the air inlet; A detection section, wherein the detection section has a detection cavity, and the detection element detects the concentration of particulate matter through the detection cavity; An air outlet section is connected to the air outlet.

[0009] In some embodiments, the air inlet section is divided into an air inlet front section connected to the air inlet and an air inlet rear section connected to the detection section. The air inlet front section is vertically arranged to the air inlet rear section, and an arc-shaped air guide surface is provided at the connection between the two.

[0010] In some embodiments, the air inlet and the air outlet are arranged on the same side of the shell.

[0011] In some embodiments, the flow channel is at least along two side walls of the shell to form a bent flow channel; and the detection cavity is arranged close to the air inlet.

[0012] In some embodiments, the flow channel is at least along two side walls of the shell to form a bent flow channel; and the detection cavity is arranged close to the air outlet.

[0013] In some embodiments, the detection element includes a light emitter and a light receiver; the light emitter is disposed on the inner ring side of the flow channel away from the side wall of the shell.

[0014] In some embodiments, the fan is disposed close to the air outlet.

[0015] In some embodiments, the shell includes a front shell, a middle shell and a rear shell that are interlocked, a partition portion is arranged in the middle shell, the first area is defined between the front shell and one side of the partition portion, and the second area is defined between the rear shell and the other side of the partition portion.

[0016] In some embodiments, a side surface of the partition portion is provided with a surrounding wall portion that surrounds a side wall of the flow channel, and the flow channel is defined between the surrounding wall portion and the rear shell.

[0017] Compared with the prior art, the advantages and positive effects of the present invention are: The above-mentioned particle concentration detection device avoids direct contact of the oil fume airflow with electronic components such as circuit boards by designing the flow channel as an independent part isolated from the first area, reduces the risk of short circuit of electronic components due to oil fume or water vapor deposition, and thus improves the safety and stability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0019] Figure 1 is a three-dimensional diagram of a particle concentration detection device of the present invention; Figure 2 An exploded view of the housing of the particle concentration detection device of the present invention; Figure 3 It is a schematic diagram of the structure of the first internal area of ​​the particle concentration detection device of the present invention, in which the front shell and the rear shell are not shown; Figure 4 for Figure 3 A front view of Figure 5 It is a schematic diagram of the structure of the second area inside the particle concentration detection device of the present invention, in which the front shell and the rear shell are not shown; Figure 6 for Figure 5 A front view of Figure 7 is a schematic diagram of the structure of the middle shell of the particle concentration detection device of the present invention, and is a view of one side of the first area; Figure 8 is a schematic diagram of the structure of the middle shell of the particle concentration detection device of the present invention, and is a view of one side of the second area; Fig. 9 It is a flow diagram of the oil smoke airflow in the particle concentration detection device of the present invention; Fig.10 is a cross-sectional view of a particle concentration detection device of the present invention; Fig.11 Schematic diagram of the flow of oil smoke airflow in some other embodiments of the present invention, where the airflow blocking structure is a perforated baffle; Fig.12 is a schematic diagram of the structure of the opening baffle; Fig.13Schematic diagram of the flow of oil smoke airflow in some other embodiments of the present invention, where the airflow blocking structure is a staggered baffle; Description of reference numerals: 100-housing; 110-front housing; 111-air inlet; 112-air outlet; 120-middle housing; 121-partition portion; 122-enclosing wall portion; 1221-through hole; 133-oil baffle; 1331-small hole; 134-first oil dripping port; 135-second oil dripping port; 130-rear housing; 200-circuit board; 300-detection element; 310-light transmitter; 320-light receiver; 400-Fan; 500-airflow blocking structure; 510-columnar structure; 520-perforated baffle; 530-staggered baffle; First area A; Second area B; Flow channel F; air inlet section f1; air inlet front section f1-1; air inlet rear section f1-2; arc-shaped air guide surface a; detection section f2; air outlet section f3; detection cavity C; Detection element installation cavity D. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In the description of the above embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0023] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0024] Reference Figure 1-Figure 13 , are some embodiments of the particle concentration detection device of the present invention.

[0025] The particle concentration detection device includes a housing 100 , a circuit board 200 , a detection element 300 and a fan 400 .

[0026] The housing 100 has an internal cavity. An air inlet 111 and an air outlet 112 are provided on the housing 100. The air inlet 111 and the air outlet 112 are used to guide the oil smoke flow through the internal cavity.

[0027] The inner cavity is divided into two opposite areas, namely the first area A and the second area B, wherein Figure 3 and Figure 4 , the first area A is a mounting area for fixing the circuit board 200; see Figure 5 and Figure 6 The second area B is a detection area, which is used to fix the detection element 300.

[0028] The circuit board 200 is used to control the working states of the detection element 300 and the fan 400 .

[0029] The detection element 300 is used to detect the concentration of particulate matter in the airflow entering the device.

[0030] like Figure 5 and Figure 6 As shown, a flow channel F isolated from the first area A is provided in the second area B, and the flow channel F is used to connect the air inlet 111 and the air outlet 112, guide the air flow to enter from the air inlet 111, and be discharged through the air outlet 112 after being detected by the detection element 300 (as shown in FIG. Fig. 9 The direction indicated by the arrow is the flow direction of the oil smoke airflow. The flow channel F is isolated from the first area A, which can prevent the airflow from entering the first area A and prevent the oil smoke airflow from directly contacting electronic components such as the circuit board 200.

[0031] The fan 400 is disposed in the flow channel F, and is used to drive air flow in the flow channel F.

[0032] The above-mentioned particulate matter concentration detection device avoids direct contact of the oil fume airflow with electronic components such as the circuit board 200 by designing the flow channel F as an independent part isolated from the installation area, reduces the risk of short circuit of electronic components caused by oil fume or water vapor deposition, and thus improves the safety and stability of the device.

[0033] In this embodiment, see Fig. 9 The flow channel F includes an air inlet section f1, a detection section f2 and an air outlet section f3 in sequence. The air inlet section f1 is connected to the air inlet 111, the detection section f2 has a detection cavity C, and the detection element 300 detects the concentration of particulate matter in the oil smoke airflow through the detection cavity C. The air outlet section f3 is connected to the air outlet 112 to discharge the detected airflow.

[0034] Furthermore, if Figure 7 As shown, the air inlet section f1 is divided into an air inlet front section f1-1 connected to the air inlet 111 and an air inlet rear section f1-2 connected to the detection section f2. The air inlet front section f1-1 and the air inlet rear section f1-2 are vertically arranged, and an arc-shaped air guide surface a is provided at the connection between the two. When the airflow enters the air inlet rear section f1-2 from the air inlet front section f1-1, the airflow changes direction through the arc-shaped air guide surface a. The design of the arc-shaped air guide surface a effectively guides the external airflow into the detection section f2, reduces the airflow turbulence, and improves the stability of the airflow through the flow channel F, thereby improving the accuracy of the detection.

[0035] In this embodiment, the flow channel F is arranged along at least two side walls of the housing 100 to form a bent airflow channel. For example, when the flow channel F is arranged along two side walls of the housing 100, an L-shaped flow channel is formed; when the flow channel F is arranged along three side walls of the housing 100, an inverted U-shaped flow channel is formed.

[0036] The detection chamber C is arranged near the air inlet 111. Since the detection element 300 is located where the airflow just enters the flow channel F, the oil smoke particles can quickly enter the detection chamber C, and the detection element 300 can immediately sense the concentration of particles in the airflow to achieve a rapid response.

[0037] In another embodiment, the detection chamber C can be arranged near the air outlet 112 (not shown), which helps to extend the path of the oil smoke airflow in the flow channel F, and the airflow tends to be stable near the air outlet 112. At this time, the detection element 300 can work in a stable airflow environment, thereby improving the reliability of the detection result and reducing the measurement error caused by airflow fluctuations.

[0038] In this embodiment, the fan 400 is disposed inside the air outlet 112, and through the action of the fan 400, the oil fume airflow can form a continuous flow in the flow channel F. The fan 400 is not only responsible for guiding the oil fume airflow into the flow channel F, but also can optimize the flow state of the oil fume particles by adjusting the airflow speed, ensuring that the particles are accurately detected when passing through the detection section f2.

[0039] In this embodiment, if Figure 1 As shown, the air inlet 111 and the air outlet 112 are arranged on the same side of the housing 100. When the particle concentration detection device is installed on the equipment, it can be ensured that the exhaust fume airflow can be discharged into the external environment. At the same time, the air inlet and the air outlet are arranged from the same side of the housing 100, which can simplify the installation layout of the detection device and other equipment components, making it easier to integrate the particle concentration detection device into a compact space.

[0040] See also Fig. 9 The detection element 300 is an optical sensor, including a light emitter 310 and a light receiver 320 .

[0041] Optical sensors measure the concentration of particles in the air based on the principle of scattered light. When light passes through air containing particles, the particles scatter the light, and the optical sensor infers the concentration of the particles by detecting the intensity of the scattered light.

[0042] Specifically, the light emitter 310 emits light to illuminate the particles in the air. The light emitter 310 may be an infrared light emitting diode (IR LED) or a laser diode. A laser light source is preferred, which has higher accuracy and stability and can meet the requirements of high-precision measurement.

[0043] The light emitted by the light emitter 310 enters the detection cavity C through the through hole opened on the flow channel F.

[0044] The optical receiver 320 is located in the detection cavity C and is used to receive light scattered by particles. The optical receiver 320 is usually a photoelectric conversion device such as a photodiode or a phototransistor, which can convert the received optical signal into an electrical signal, and then obtain the concentration information of the particles through circuit processing.

[0045] In this embodiment, the light emitter 310 is disposed on the inner ring side of the flow channel F away from the side wall of the shell 100, approximately in the middle of the shell 100, which can optimize the utilization of the internal space and make the structural layout of the entire device more compact.

[0046] In this embodiment, if Figure 2 As shown, the housing 100 includes a front housing 110, a middle housing 120 and a rear housing 130 that are interlocked. An air inlet 111 and an air outlet 112 are provided on the front housing 110. Figure 7As shown, a partition part 121 is provided in the middle shell 120, a first area A is defined between the front shell 110 and one side of the partition part 121, and a second area B is defined between the rear shell 130 and the other side of the partition part 121. The circuit board 200 is fixed on the partition part 121. The front shell 110 and the rear shell 130 wrap the middle shell 120 therein, and buckles are provided on the middle shell 120, which are fixedly connected to the front shell 110 and the rear shell 130 through the buckle structure.

[0047] like Figure 8 As shown, a surrounding wall portion 122 is disposed on the side of the partition portion 121 to form a side wall of the flow channel F, and the flow channel F is defined between the surrounding wall portion 122 , the partition portion 121 and the rear shell 130 .

[0048] See also Figure 5 , 6 and Fig. 9 The air inlet section f1 of the flow channel F is also provided with an airflow blocking structure 500, which is located upstream of the detection chamber C. The airflow blocking structure 500 can cause the oil fume airflow in the flow channel F to collide multiple times, and through the collision, larger particles in the oil fume airflow can be decomposed into smaller particles before entering the detection chamber C.

[0049] The particle concentration detection device can prevent large particles from settling and accumulating oil in the detection cavity C through the collision and decomposition effect of the airflow blocking structure 500, thereby avoiding contamination of the detection element 300 and affecting the detection accuracy of the detection element 300. At the same time, large particles are mechanically collided by the airflow blocking structure 500 and split into small particles with similar diameters, which are more evenly distributed when passing through the detection element 300, thereby improving the detection accuracy and detection efficiency.

[0050] In this embodiment, the airflow blocking structure 500 includes a plurality of columnar structures 510, which are arranged in a staggered manner in the flow channel F. The cross-section of the columnar structure 510 is not specifically limited, and may be circular, elliptical, diamond-shaped, etc. The columnar structures 510 are arranged in a staggered manner inside the flow channel F, so that the particles in the oil smoke airflow can undergo multiple collision and separation processes when passing through, thereby effectively improving the decomposition efficiency of large particles.

[0051] In other embodiments, Fig.11 and Fig.12As shown, the airflow blocking structure 500 may adopt an open baffle plate 520 having a plurality of openings, and the open baffle plates 520 are sequentially arranged in the flow channel F along the airflow direction. A plurality of open baffle plates 520 are arranged in a staggered manner, wherein the openings on adjacent baffle plates do not completely overlap, so that the particles in the oil smoke airflow collide and separate multiple times when passing through the open baffle plates 520, further enhancing the decomposition effect of large particles. The open baffle plates 520 may be arranged tilted relative to the airflow direction so that the oil droplets accumulated on the baffle plates can drip smoothly.

[0052] In other embodiments, Fig.13 As shown, the airflow blocking structure 500 is designed with staggered baffles 530. Multiple staggered baffles 530 form an S-shaped circuitous flow channel in the flow channel F. Through this structure, the oil smoke airflow undergoes multiple turns in the flow channel F, and the particles will continuously collide and separate in the flow channel F, reducing the presence of large particles. The staggered baffles 530 can be set obliquely relative to the airflow direction so that the oil droplets accumulated on the baffles can drip smoothly.

[0053] In some other embodiments, the airflow blocking structure 500 may be a labyrinth flow channel structure (not shown). The labyrinth flow channel has multiple tortuous paths. When the oil fume airflow passes through the labyrinth flow channel, the airflow direction changes continuously, causing the particles to collide in different directions, thereby decomposing smaller particles and reducing the deposition of particles. At the same time, the tortuous path in the labyrinth structure can effectively reduce airflow turbulence, while ensuring that the particles are evenly distributed in the flow channel F, and finally when entering the detection chamber C, efficient and accurate detection can be ensured.

[0054] In this embodiment, the airflow blocking structure 500 and the detection chamber C are both arranged near the air inlet 111. For ease of manufacturing or installation, the airflow blocking structure 500 is arranged in the air inlet rear section f1-2. By arranging the airflow blocking structure 500 near the air inlet 111, the particulate matter can be decomposed and processed at the beginning of the oil smoke airflow entering the flow channel F, reducing the interference of large particles on the subsequent detection process. The detection chamber C is arranged near the airflow blocking structure 500, and the detection element 300 can immediately sense the concentration of particulate matter in the airflow to achieve a rapid response.

[0055] In other embodiments, the airflow blocking structure 500 is arranged close to the air inlet 111, and the detection cavity C is set close to the air outlet 112, so as to extend the path of the oil smoke airflow in the flow channel F and improve the reliability of the detection result.

[0056] The airflow blocking structure 500 is an integrated structure with the flow channel F, or a detachable installation structure. The integrated structure can improve the overall stability of the device and reduce the assembly process; while the detachable structure is convenient for maintenance and cleaning. The user can disassemble and replace the airflow blocking structure 500 according to the actual use situation to ensure that the device is always in the best working condition.

[0057] Since the light emitting window of the light emitter 310 is relatively sensitive, once the smoke, water vapor or particulate matter directly contacts the light emitter 310, it is easy to cause the emission intensity and angle of the light to deviate, thereby affecting the accuracy of the detection result. In order to prevent the smoke, water vapor, etc. from affecting the light emitter 310 and affecting its detection accuracy, in this embodiment, Fig. 9 and Fig.10 As shown, a detection element installation cavity D is provided on one side of the detection cavity C, a light emitter 310 is provided in the detection element installation cavity D, a through hole 1221 is provided on the side wall of the flow channel F, and the light emitted by the light emitter 310 enters the detection cavity C through the through hole. At least one layer of oil baffle 133 is provided between the light emitter 310 and the detection cavity C, and a small hole 1331 for light to pass through is opened on the oil baffle 133.

[0058] The particle concentration detection device isolates the light emitter 310 from the oil fume airflow by setting a detection element installation cavity D on one side of the detection cavity C, thereby preventing the light emitter 310 from being directly exposed to the oil fume airflow; at the same time, by setting at least one layer of oil baffle 133, the small holes on the oil baffle 133 can not only allow light to pass through smoothly, but also effectively block the invasion of most oil fume particles, further preventing the oil fume airflow from entering the detection element installation cavity D and directly contacting the light emitter 310, thereby greatly improving the anti-pollution ability of the device, allowing the light emitter 310 to maintain normal operation for a long time in a relatively harsh oil fume environment, thereby ensuring the accuracy and reliability of the detection.

[0059] In order to effectively discharge the oil accumulated in the flow channel F, the device is provided with a first oil drop port 134 at the bottom of the flow channel F near the air outlet 112, and a second oil drop port 135 (such as Fig. 9 The hollow arrow indicates the flow direction of the oil droplets). The two oil droplets can smoothly discharge the oil, keep the flow channel F clean, prevent the accumulation of oil from hindering the normal flow of the airflow in the flow channel F, and ensure the long-term stable operation of the device.

[0060] In this embodiment, the air inlet 111 and the air outlet 112 are both arranged near the bottom of the housing 100, and the flow channel F is arranged in a roughly inverted U shape in the housing 100. In order to facilitate the complete discharge of oil and dirt in the flow channel F, the top portion of the flow channel F is arranged slightly tilted downward to facilitate the oil droplets to flow downward under the action of gravity and flow out from the first oil drop port 134 at the outlet. It can be understood that in other embodiments, when the detection chamber C is arranged near the air outlet 112, the top flow channel portion is tilted toward the air inlet 111, so that the oil droplets are discharged from the second oil drop port 135 on the lower side of the air inlet 111, avoiding flowing into the detection chamber C to affect the detection accuracy.

[0061] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to replace some of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions claimed to be protected by the present invention.

Claims

1. A particle concentration detection device, characterized in that: include: A shell having an internal cavity, wherein an air inlet and an air outlet are provided on the shell; the internal cavity is divided into a first area and a second area opposite to each other, the second area is provided with a flow channel isolated from the first area; the flow channel communicates with the air inlet and the air outlet; a detection element disposed in the second region and configured to detect a concentration of particles in the flow channel; A fan, disposed in the flow channel, for driving the air flow in the flow channel; The circuit board is arranged in the first area and is electrically connected to the detection element and / or the fan.

2. The particle concentration detection device according to claim 1, characterized in that: The flow channel comprises in sequence: An air inlet section, the air inlet section being in communication with the air inlet; A detection section, wherein the detection section has a detection cavity, and the detection element detects the concentration of particulate matter through the detection cavity; An air outlet section is connected to the air outlet.

3. The particle concentration detection device according to claim 2, characterized in that: The air inlet section is divided into an air inlet front section connected to the air inlet and an air inlet rear section connected to the detection section. The air inlet front section is vertically arranged with the air inlet rear section, and an arc-shaped air guide surface is arranged at the connection between the two.

4. The particle concentration detection device according to claim 2, characterized in that: The air inlet and the air outlet are arranged on the same side of the shell.

5. The particle concentration detection device according to claim 2, characterized in that: The flow channel is at least along the two side walls of the shell to form a bent flow channel; the detection cavity is arranged close to the air inlet.

6. The particle concentration detection device according to claim 2, characterized in that: The flow channel is at least along the two side walls of the shell to form a bent flow channel; the detection cavity is arranged close to the air outlet.

7. The particle concentration detection device according to claim 5 or 6, characterized in that: The detection element comprises a light emitter and a light receiver; the light emitter is arranged on the inner ring side of the flow channel away from the side wall of the shell.

8. The particle concentration detection device according to claim 1, characterized in that: The fan is arranged close to the air outlet.

9. The particle concentration detection device according to claim 1, characterized in that: The shell includes a front shell, a middle shell and a rear shell that are interlocked, a partition part is arranged in the middle shell, the first area is defined between the front shell and one side of the partition part, and the second area is defined between the rear shell and the other side of the partition part.

10. The particle concentration detection device according to claim 9, characterized in that: A surrounding wall portion which forms a side wall of the flow channel is disposed on the side surface of the partition portion, and the flow channel is defined between the surrounding wall portion and the rear shell.

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