Secondary suction type oil fume exhauster

Abstract

This invention relates to the field of kitchen appliance technology, specifically a secondary smoke extraction range hood, comprising a smoke collection chamber, a fan, an air inlet duct, and an extraction mechanism. The smoke collection chamber has a smoke inlet. One end of the air inlet duct is connected to the fan's air inlet, and the other end is located outside the smoke collection chamber to form secondary smoke extraction. The extraction mechanism includes an air outlet duct and a smoke inlet duct, with the smoke inlet duct sleeved outside the air outlet duct to form a smoke inlet channel. The air outlet duct is connected to the fan's air outlet, and the smoke inlet duct is connected to the smoke collection chamber. The airflow discharged from the fan forms an extraction negative pressure through the air outlet duct, causing the gas in the smoke collection chamber to enter the smoke inlet duct and be discharged outwards. By setting up the extraction mechanism, the fumes are discharged through the extraction channel, preventing them from directly entering the fan impeller, effectively reducing oil adhesion, lowering operating noise, and extending the service life of the motor and the entire machine. A single fan simultaneously achieves extraction smoke and secondary smoke extraction, forming dual negative pressure smoke control, resulting in more complete oil fume adsorption, less diffusion, and significantly improved smoke extraction efficiency.

Description

Technical Field

[0001] This invention relates to the field of kitchen appliance technology, specifically to a secondary smoke extraction type range hood. Background Technology

[0002] As an essential kitchen appliance for purifying cooking fumes, the range hood's smoke extraction efficiency, ventilation smoothness, noise reduction, and lifespan directly impact the user experience. Existing traditional range hoods generally employ a direct-suction, direct-exhaust structure, with the fan typically fixed at the top or middle of the hood. This results in numerous bends in the ductwork and high airflow resistance, leading to low exhaust efficiency. Cooking fumes easily enter the centrifugal fan, causing grease buildup on the impeller, severe motor overheating, excessive noise, and a shortened lifespan. Furthermore, the traditional range hood structure struggles to achieve multiple negative pressure suction, allowing cooking fumes to easily diffuse and escape, resulting in unsatisfactory purification and exhaust effects. Summary of the Invention

[0003] The purpose of this invention is to propose a secondary smoke extraction type range hood to solve the problems of easy oil accumulation in the fan, difficulty in achieving multiple negative pressure smoke extraction, and unsatisfactory smoke purification effect in the existing technology.

[0004] To achieve the above objectives, this invention proposes an ejector-type range hood that acts on a stovetop, comprising a smoke collection chamber, a fan, an air inlet duct, and an ejector mechanism; the smoke collection chamber is provided with a smoke inlet; one end of the air inlet duct is connected to the air inlet of the fan, and the other end is located outside the smoke collection chamber to form secondary smoke extraction; the ejector mechanism includes an air outlet duct and a smoke inlet duct, with the smoke inlet duct sleeved outside the air outlet duct to form a smoke inlet channel; the air outlet duct is connected to the air outlet of the fan, and the smoke inlet duct is connected to the smoke collection chamber; the airflow discharged by the fan forms an ejector negative pressure through the air outlet duct, causing the gas in the smoke collection chamber to enter the smoke inlet duct and be discharged outwards.

[0005] Furthermore, the fan is located on the side of the smoke collection chamber or below the stove. The fan arrangement is flexible, can be adapted to concealed installation, has a shorter and straighter air duct, lower air resistance, and stronger smoke extraction power.

[0006] Furthermore, at least a portion of the air inlet duct is located in the upper part of the smoke collection chamber, with the end of the air inlet duct furthest from the fan facing the front of the smoke collection chamber. The secondary smoke inlet is close to the area where oil fumes rise, resulting in more reasonable negative pressure coverage and further enhancing the oil fume capture capability.

[0007] Further, the air inlet duct includes a first duct, a second duct, and a connecting duct. One end of the first duct and one end of the second duct are both located outside the smoke collection room. The other end of the first duct is connected to the second duct through the connecting duct, and the other end of the second duct is connected to the air inlet of the fan; or The air inlet duct includes a first duct, a second duct, and a connecting duct. One end of the first duct and one end of the second duct are both located outside the smoke collection room. The other ends of the first duct and the second duct are both connected to the connecting duct, which is connected to the air inlet of the fan. The air inlet path is flexible and diverse, enabling secondary smoke extraction from both sides or multiple points, resulting in a more uniform negative pressure distribution.

[0008] Furthermore, one end of the first pipe and one end of the second pipe are located on opposite sides of the smoke inlet. This creates a secondary negative pressure for smoke extraction from both sides of the smoke inlet, ensuring that the fumes are gathered without any blind spots and preventing lateral escape.

[0009] Furthermore, the smoke inlet duct includes an inner pipe and an outer pipe. The inner pipe is fitted onto the air outlet duct, and the outer pipe is fitted onto the inner pipe, with the two connected by a connecting rib. A first smoke inlet channel is formed between the inner pipe and the outer pipe. This forms a stable annular smoke inlet channel, resulting in more uniform negative pressure and a larger range for oil fume adsorption.

[0010] Furthermore, the inner diameter of the inner tube is larger than the outer diameter of the outlet duct, and a second smoke inlet channel is formed between the inner tube and the outlet duct. This smoke inlet duct enables dual-channel smoke intake, increasing the smoke intake volume, enhancing the ejector smoke exhaust capacity, and resulting in more stable airflow.

[0011] Furthermore, the inner diameter of the outer tube is 1.2 to 2 times the inner diameter of the inner tube. The annular gap ratio is reasonable, the ejector negative pressure is stable, the wind resistance is low, the noise is low, and the smoke extraction efficiency is better.

[0012] Furthermore, the ejector mechanism also includes a smoke exhaust duct, one end of which is connected to the end of the smoke inlet duct furthest from the smoke collection chamber, and the other end of which is a smoke exhaust outlet. This achieves centralized and directional exhaust of smoke, preventing backflow and ensuring smoother smoke extraction.

[0013] Furthermore, the ejector mechanism also includes a sealing sleeve, which is fitted onto the end of the smoke inlet pipe away from the smoke collection chamber. The upper end of the sealing sleeve is open, and one end of the smoke exhaust pipe is embedded in the opening of the sealing sleeve to connect with the smoke inlet pipe. This provides good sealing performance, prevents smoke leakage, and is simple and reliable to assemble, disassemble, and maintain. This invention discloses a secondary smoke extraction type range hood, which has at least the following beneficial effects: By employing a structure that combines an extraction mechanism with an air inlet duct, the high-speed airflow discharged from the fan forms a stable extraction negative pressure through the air outlet duct, efficiently driving the oil fumes in the smoke collection chamber into the smoke inlet channel and quickly expelling them. The oil fumes are driven out by the extraction airflow, eliminating the need for them to directly enter the fan, thus reducing oil adhesion inside the fan, lowering operating noise, and improving the overall operational stability and service life of the machine. Furthermore, the air inlet duct forms secondary smoke extraction outside the smoke collection chamber, allowing the fan to collect residual smoke that was not extracted from the smoke collection chamber while it is drawing in air. This achieves a dual smoke control effect of primary extraction smoke extraction and secondary auxiliary smoke extraction, significantly improving the oil fume adsorption and concentration capacity, effectively preventing oil fume diffusion and escape, and greatly improving smoke exhaust efficiency. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort. Figure 1 This is a schematic diagram of the structure of the secondary smoke extraction type range hood of the present invention; Figure 2 This is a schematic diagram of the smoke collection chamber of the present invention; Figure 3 This is a schematic diagram of the air inlet duct of the present invention; Figure 4 This is a schematic diagram of the ejector mechanism of the present invention; Figure 5 This is a schematic diagram of the exploded structure of the ejector mechanism of the present invention; Figure 6 This is a cross-sectional structural schematic diagram of the ejector mechanism of the present invention; Figure 7 This is a schematic diagram of the smoke inlet pipe of the present invention; Figure 8 This is a schematic diagram of the structure of the secondary smoke extraction range hood of the present invention applied to a stove.

[0015] In the attached diagram: 10-Smoke collection chamber, 101-Smoke inlet, 20-Fan, 30-Air inlet duct, 31-First duct, 32-Second duct, 33-Connecting duct, 40-Ejector mechanism, 41-Air outlet duct, 42-Smoke inlet duct, 421-Inner pipe, 422-Outer pipe, 423-Connecting rib, 424-First smoke inlet channel, 425-Second smoke inlet channel, 43-Smoke exhaust duct, 431-Smoke exhaust outlet, 44-Sealing sleeve, 100-Stove platform. The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0018] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention. Please see Figure 1 This invention provides a secondary smoke extraction type range hood, which is installed above the stove 100 and mainly includes a smoke collection chamber 10, a fan 20, an air inlet duct 30, and an extraction mechanism 40. Please refer to [link / reference]. Figure 2 The smoke collection chamber 10 has a hollow cavity structure, with a smoke inlet 101 on the side facing the stove 100 to collect cooking fumes. The fan 20 is a centrifugal fan, serving as the power source for the entire unit, creating both negative pressure intake and high-speed airflow exhaust. The air inlet duct 30 is a rigid or flexible pipe, with one end sealed to the air inlet of the fan 20, and the other end extending upwards and positioned outside the smoke collection chamber 10, forming a secondary smoke extraction port. Please refer to [link / reference]. Figure 1 and Figure 4The ejector mechanism 40 includes an air outlet duct 41 and a smoke inlet duct 42. The smoke inlet duct 42 is coaxially sleeved around the air outlet duct 41, and a uniform gap is maintained between the smoke inlet duct 42 and the air outlet duct 41 to form an annular smoke inlet channel. One end of the air outlet duct 41 is sealed and connected to the air outlet of the fan 20 for outputting high-speed airflow; one end of the smoke inlet duct 42 is sealed and connected to the interior of the smoke collection chamber 10 for receiving the oil fumes inside the smoke collection chamber 10.

[0019] During operation, the fan 20 is powered on and starts, sending a high-speed airflow into the outlet duct 41 and spraying it forward. According to the fluid entrainment principle, the high-speed airflow creates a continuous negative pressure in the annular smoke inlet channel, drawing the gas in the smoke collection chamber 10 into the smoke inlet duct 42. The smoke collection chamber 10 has a smoke inlet 101, through which the oil fumes enter the smoke collection chamber 10. Finally, the oil fumes in the smoke collection chamber 10 are drawn into the smoke inlet duct 42, mixed with the high-speed airflow, and then discharged outward. On the other hand, a negative pressure is formed at the end of the inlet duct 30, and the fan 20 performs secondary adsorption on the oil fumes diffused outside the smoke collection chamber 10 when it draws in air.

[0020] By employing a structure that combines the ejector mechanism 40 with the air inlet duct 30, the high-speed airflow discharged from the fan 20 forms a stable ejector negative pressure through the outlet duct 41, which can efficiently drive the oil fumes in the smoke collection chamber 10 into the smoke inlet channel and quickly discharge them. Simultaneously, the air inlet duct 30 creates secondary smoke extraction outside the smoke collection chamber 10. While the fan 20 is drawing in air, it can also suck away the oil fumes overflowing to the outside of the smoke collection chamber 10, achieving a dual smoke control effect of primary ejector smoke extraction and secondary auxiliary smoke extraction. This significantly improves the oil fume adsorption and concentration capacity, effectively prevents oil fume diffusion and escape, and greatly improves smoke exhaust efficiency. Furthermore, the oil fumes are discharged driven by the ejector airflow, without directly entering the fan 20, which reduces the adhesion of oil stains inside the fan 20, lowers operating noise, and improves the overall operational stability and service life of the machine. The fan 20 can be installed on the left or right side of the smoke collection chamber 10, or inside the cabinet below the stove 100. Please refer to [link / reference]. Figure 8 Preferably, the fan 20 is installed inside the cabinet below the stove 100. The fan 20 is connected to the main body of the range hood via a short, straight duct. The air outlet of the fan 20 is aligned with the air outlet duct 41 in a straight line, and the air inlet of the fan 20 is directly connected to the air inlet duct 30. There are no unnecessary bends or protrusions inside the duct.

[0021] During operation, the fan 20 is in a low position, and the airflow path from the fan 20 to the ejector mechanism 40 is shorter and smoother. The airflow resistance and air pressure loss are significantly reduced, and the high-speed airflow can enter the air outlet duct 41 at a higher speed, making the ejector negative pressure stronger and the smoke extraction and exhaust power more sufficient.

[0022] The flexible placement of the fan 20 allows for installation in concealed or built-in cabinets, enhancing the overall aesthetics. The fan 20 is ideally positioned below the cooktop 100, a low-lying arrangement that lowers the center of gravity, resulting in more stable operation, less vibration, and lower noise. While fumes are drawn upwards for extraction, the low-lying fan 20 keeps them away from these fumes, significantly reducing grease buildup inside the fan. Furthermore, the short, straight, and smooth air duct reduces air resistance, resulting in stronger suction and higher smoke extraction efficiency. Please see Figure 1 The main body of the air inlet duct 30 is laid along the upper surface of the smoke collection chamber 10, with at least one section located in the upper area of ​​the smoke collection chamber 10. The air inlet duct 30 is arranged close to the outer wall of the smoke collection chamber 10. The end of the air inlet duct 30 away from the fan 20 is a free end, which faces the front of the smoke collection chamber 10, i.e., the main direction of the rising and diffusion of oil fumes, so that the secondary smoke extraction port is directly aimed at the source area of ​​oil fumes. During operation, the fan 20 generates air intake through the air inlet duct 30, forming a stable and concentrated negative pressure zone above and in front of the smoke collection chamber 10, which can capture the oil fumes that have not been sucked up by the smoke collection chamber 10 and prevent the oil fumes from escaping towards the human body and the kitchen space. The air inlet duct 30 is reasonably laid out, the secondary smoke extraction port is in a better position, and the negative pressure covers the main diffusion path of oil fumes, so that the smoke is collected more promptly and thoroughly, further reducing the probability of oil fume escape and improving the smoking experience.

[0023] Please see Figure 3 The air intake duct 30 includes a first duct 31, a second duct 32, and a connecting duct 33. The first duct 31 and the second duct 32 are both independent branch pipes, and their upper smoke inlets are arranged outside the smoke collection chamber 10 to expand the secondary smoke extraction range.

[0024] In this embodiment, the lower end of the first pipe 31 is connected to one end of the connecting pipe 33, and the other end of the connecting pipe 33 is connected to the second pipe 32. The lower end of the second pipe 32 is then connected to the air inlet of the fan 20, forming a series air intake structure. In other embodiments, the lower ends of both the first pipe 31 and the second pipe 32 are connected to the connecting pipe 33. The connecting pipe 33 collects the airflow and then connects to the air inlet of the fan 20, forming a parallel air intake structure.

[0025] During operation, the fan 20 generates negative pressure, causing the first pipe 31 and the second pipe 32 to simultaneously draw air from different positions outside the smoke collection chamber 10, creating a multi-point, distributed secondary smoke extraction effect. The air intake path can be flexibly selected in series or parallel to adapt to different installation spaces and smoke control needs; multi-point air intake makes the negative pressure distribution more uniform, the smoke collection range larger, and the smoke extraction more stable.

[0026] The smoke extraction port of the first pipe 31 is located on the left side of the smoke inlet 101, and the smoke extraction port of the second pipe 32 is located on the right side of the smoke inlet 101. The two ports are symmetrically distributed on both sides above the smoke inlet 101. As cooking fumes rise from the stove 100 and move towards the smoke inlet 101, the two pipes simultaneously generate negative pressure, clamping and gathering the fumes from both sides, forcing them to converge towards the center of the smoke inlet 101 and preventing them from overflowing from the sides. This symmetrical double-sided smoke extraction creates a closed smoke control zone, eliminating any lateral escape space for the fumes and ensuring thorough smoke collection. This is especially suitable for dual-burner stoves and situations with heavy cooking fumes, resulting in cleaner smoke extraction. Please see Figures 5 to 7 The smoke inlet duct 42 adopts a double-layer sleeve structure, including an inner pipe 421 and an outer pipe 422. The inner pipe 421 is directly sleeved on the outside of the exhaust duct 41, and the outer pipe 422 is then sleeved on the outside of the inner pipe 421. Several connecting ribs 423 are arranged circumferentially between the inner pipe 421 and the outer pipe 422. The two ends of the connecting ribs 423 are fixedly connected to the outer wall of the inner pipe 421 and the inner wall of the outer pipe 422, respectively, so that the inner and outer pipes are coaxial and the spacing is uniform. The inner pipe 421 and the outer pipe 422 form an annular first smoke inlet channel 424. During operation, the exhaust duct 41 ejects a high-speed airflow, forming a uniform and stable annular ejector negative pressure zone between the inner pipe 421 and the outer pipe 422. After the oil fumes enter the first smoke inlet channel 424 from the smoke collection chamber 10, they flow smoothly along the annular channel, and are not prone to turbulence and backflow. The double-layer sleeve structure makes the ejector negative pressure more uniform, the adsorption range larger, and the oil fume flow smoother, effectively reducing airflow noise and improving the stability of ejector smoke exhaust.

[0027] Please see Figures 5 to 7 The inner diameter of the inner tube 421 is larger than the outer diameter of the outlet duct 41, maintaining a uniform gap between the outer wall of the outlet duct 41 and the inner wall of the inner tube 421, forming a second smoke inlet channel 425. At this time, the ejector mechanism 40 simultaneously possesses both a first smoke inlet channel 424 and a second smoke inlet channel 425, forming a double-layer annular smoke inlet structure. High-speed airflow is ejected from the outlet duct 41, simultaneously driving airflow within the first smoke inlet channel 424 and the second smoke inlet channel 425, creating a dual ejection effect that significantly increases the amount of oil fume drawn in and the speed of smoke exhaust. The dual-channel synchronous ejection results in a larger smoke intake and faster smoke exhaust, significantly enhancing the ejection capability and enabling rapid response to scenarios with large amounts of oil fume, such as stir-frying, resulting in more efficient smoke exhaust.

[0028] The inner diameter of the outer tube 422 is set to 1.2 to 2 times the inner diameter of the inner tube 421, so that the width of the annular gap between the inner tube 421 and the outer tube 422 is within the optimal range. Preferably, the inner diameter of the outer tube 422 is set to 1.5 times the inner diameter of the inner tube 421; for example, the inner diameter of the inner tube 421 is set to 16cm, and the inner diameter of the outer tube 422 is set to 24cm; the outer tube 422 and the inner tube 421 are coaxially arranged, forming an annular drainage gap between them. The 1.5 times diameter ratio of the outer tube 422 to the inner tube 421 results in a reasonable structural gap, stable ejector negative pressure, which can not only increase the oil fume adsorption range and prevent oil fume escape, but also reduce the air duct resistance, improve the overall smoke exhaust efficiency under low power consumption conditions, and effectively reduce the overall machine operating noise.

[0029] Please see Figure 5 and Figure 6 The ejector mechanism 40 also includes a smoke exhaust duct 43. The smoke exhaust duct 43 is a rigid or flexible exhaust pipe, one end of which is sealed and connected to the end of the smoke inlet duct 42 away from the smoke collection chamber 10, and the other end is a smoke exhaust port 431, directly connected to the outside or a public smoke exhaust duct. After being drawn in by the ejector mechanism 40, the fumes directly enter the smoke exhaust duct 43 and are discharged outwards along a fixed path, without contacting other components inside the machine, preventing backflow, smoke leakage, or stagnation. The smoke exhaust path is closed, directional, and smooth, avoiding the accumulation of fumes within the machine, reducing internal oil buildup, lowering cleaning frequency, and improving the overall durability of the machine.

[0030] Please see Figure 5 and Figure 6 The ejector mechanism 40 also includes a sealing sleeve 44. The sealing sleeve 44 is a sleeve structure with openings at both the upper and lower ends. The sealing sleeve 44 is tightly fitted onto the outer wall of the end of the smoke inlet pipe 42 furthest from the smoke collection chamber 10. One end of the exhaust pipe 43 is inserted through the upper opening of the sealing sleeve 44, achieving a sealed connection with the smoke inlet pipe 42. This connection provides strong sealing, preventing smoke leakage and oil dripping; the plug-in assembly structure is simple, easy to install and disassemble, and facilitates later cleaning, maintenance, and component replacement. The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A secondary smoke extraction type range hood, acting on a stovetop (100), characterized in that, include: Smoke collection chamber (10), wherein the smoke collection chamber (10) is provided with a smoke inlet (101); Fan (20); An air inlet duct (30) has one end connected to the air inlet of the fan (20) and the other end located outside the smoke collection chamber (10) to form secondary smoke extraction; The ejector mechanism (40) includes an air outlet duct (41) and a smoke inlet duct (42). The smoke inlet duct (42) is sleeved on the outside of the air outlet duct (41) and a smoke inlet channel is formed between the two. The air outlet duct (41) is connected to the air outlet of the fan (20), and the smoke inlet duct (42) is connected to the smoke collection chamber (10). The exhaust air from the fan (20) forms an ejector negative pressure through the exhaust pipe (41), so that the gas in the smoke collection chamber (10) enters the smoke inlet pipe (42) and is discharged outward.

2. The secondary smoke extraction type range hood according to claim 1, characterized in that, The fan (20) is located on the side of the smoke collection chamber (10) or below the stove (100).

3. The secondary smoke extraction type range hood according to claim 1, characterized in that, At least a portion of the air inlet duct (30) is located at the upper part of the smoke collection chamber (10), and the end of the air inlet duct (30) away from the fan (20) faces the front of the smoke collection chamber (10).

4. A secondary smoke extraction type range hood according to claim 1, characterized in that, The air inlet duct (30) includes a first duct (31), a second duct (32), and a connecting duct (33). One end of the first duct (31) and one end of the second duct (32) are both located outside the smoke collection chamber (10). The other end of the first duct (31) is connected to the second duct (32) through the connecting duct (33), and the other end of the second duct (32) is connected to the air inlet of the fan (20); or The air inlet duct (30) includes a first duct (31), a second duct (32) and a connecting duct (33). One end of the first duct (31) and one end of the second duct (32) are located outside the smoke collection chamber (10). The other end of the first duct (31) and the other end of the second duct (32) are connected to the connecting duct (33). The connecting duct (33) is connected to the air inlet of the fan (20).

5. A secondary smoke extraction type range hood according to claim 4, characterized in that, One end of the first pipe (31) and one end of the second pipe (32) are located on both sides of the smoke inlet (101).

6. A secondary smoke extraction type range hood according to claim 1, characterized in that, The smoke inlet duct (42) includes an inner pipe (421) and an outer pipe (422). The inner pipe (421) is fitted onto the air outlet duct (41), and the outer pipe (422) is fitted onto the inner pipe (421). The two are connected by a connecting rib (423). A first smoke inlet channel (424) is formed between the inner pipe (421) and the outer pipe (422).

7. A secondary smoke extraction type range hood according to claim 6, characterized in that, The inner diameter of the inner tube (421) is larger than the outer diameter of the air outlet duct (41), and a second smoke inlet channel (425) is formed between the inner tube (421) and the air outlet duct (41).

8. A secondary smoke extraction type range hood according to claim 6, characterized in that, The inner diameter of the outer tube (422) is 1.2 to 2 times the inner diameter of the inner tube (421).

9. A secondary smoke extraction type range hood according to claim 1, characterized in that, The ejector mechanism (40) also includes a smoke exhaust pipe (43), one end of which is connected to the end of the smoke inlet pipe (42) away from the smoke collection chamber (10), and the other end of the smoke exhaust pipe (43) is a smoke exhaust port (431).

10. A secondary smoke extraction type range hood according to claim 9, characterized in that, The ejector mechanism (40) also includes a sealing sleeve (44), which is fitted onto the end of the smoke inlet pipe (42) away from the smoke collection chamber (10). The upper end of the sealing sleeve (44) is open, and one end of the smoke exhaust pipe (43) is embedded in the opening of the sealing sleeve (44) to communicate with the smoke inlet pipe (42).

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