A range hood

Abstract

The invention discloses a range hood, comprising a fan frame, an air inlet component and a fan system; the air inlet component comprises an upper smoke collecting hood and a lower smoke collecting hood, the right side ends of the upper smoke collecting hood and the lower smoke collecting hood are connected and fluidically communicated by a first connecting hood, the left side ends of the upper smoke collecting hood and the lower smoke collecting hood are connected and fluidically communicated by a second connecting hood, the first connecting hood and the second connecting hood are both semicircular or arc-shaped, and an air inlet is provided on the lower surface of the lower smoke collecting hood; an air inlet duct is formed in the lower smoke collecting hood, an air outlet duct which is fluidically communicated with the inside of the fan frame is formed in the upper smoke collecting hood, and the air inlet is only fluidly communicated with the air inlet duct; acceleration ducts are also formed in the upper smoke collecting hood and the lower smoke collecting hood, and centrifugal ducts are formed in the first connecting hood and the second connecting hood, and the oil smoke airflow at least passes through the first connecting hood, the upper smoke collecting hood, the second connecting hood, the lower smoke collecting hood, and the air ducts sequentially connected in the first connecting hood from the air inlet duct and is discharged into the fan frame from the air outlet duct.

Description

Technical Field

[0001] The invention relates to an oil fume purification device, in particular to a range hood. Background Art

[0002] Range hoods have become one of the indispensable kitchen appliances in modern families. Usually, range hoods include top suction type and side suction type. Top suction range hoods are more and more widely used due to their advantages such as neatness, lightness and small space occupation. Top suction range hoods usually include a fume hood and a fan frame located on the fume hood. The fan frame is equipped with a volute, an impeller and a motor driving the impeller. The center of the fume hood is provided with an air inlet directly connected to the high negative pressure area where the fan is located.

[0003] Common range hoods usually have a filter at the air inlet. When the oil smoke passes through the filter, large particles (generally larger than PM10) of oil will be filtered out, and then the remaining small particles of oil will be further filtered out through the centrifugal force of the fan. If the filter holes are too large, a large amount of large particles of oil smoke will enter the fan system. If a large amount of oil smoke particles are attached to the impeller, the dynamic balance of the impeller will be destroyed, causing the range hood to vibrate more and the noise to increase. If the filter holes are too small, the air inlet resistance will increase, which will lead to reduced fan efficiency and increased energy consumption. In addition, the filter holes are too small and are prone to clogging. Clogged filter holes will reduce the smoking effect and affect the cooking experience. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a range hood with improved oil fume filtering capability and to maintain long-term stable operation in view of the deficiencies in the above-mentioned prior art.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a range hood, comprising a fan frame, an air inlet assembly arranged under the fan frame, and a fan system arranged in the fan frame; characterized in that:

[0006] The air inlet assembly comprises an upper smoke collecting hood and a lower smoke collecting hood arranged below the upper smoke collecting hood, the right ends of the upper smoke collecting hood and the lower smoke collecting hood are connected and fluidly communicated via a first connecting hood, the left ends of the upper smoke collecting hood and the lower smoke collecting hood are connected and fluidly communicated via a second connecting hood, the first connecting hood and the second connecting hood are both semicircular or arc-shaped and protrude in directions away from each other, and an air inlet is provided on the lower surface of the lower smoke collecting hood;

[0007] The upper smoke collecting hood, the lower smoke collecting hood, the first connecting hood and the second connecting hood are all hollow hoods, an air inlet duct is formed in the lower smoke collecting hood, an air outlet duct connected to the internal fluid of the fan frame is formed in the upper smoke collecting hood, and the air inlet is only connected to the air inlet duct fluid;

[0008] Accelerating air ducts are formed in the upper smoke collecting hood and the lower smoke collecting hood, and semicircular or arc-shaped centrifugal air ducts are formed in the first connecting hood and the second connecting hood. The oil smoke airflow at least passes through the first connecting hood, the upper smoke collecting hood, the second connecting hood, the lower smoke collecting hood, and the air ducts connected in sequence in the first connecting hood, and then is discharged into the fan frame from the air outlet duct.

[0009] Therefore, by forming multiple centrifugal air ducts and acceleration air ducts, centrifugal force is used to separate the oil smoke, and the acceleration channel is used to increase the initial velocity entering the centrifugal air duct, so that the oil smoke is filtered in large quantities before entering the fan system, and the oil stains do not clog the filter, so that the range hood can maintain long-term stable operation.

[0010] Preferably, triple centrifugal filtration is adopted, the air inlet duct is closed at the left end portion near the first connecting cover, the right end portion of the air inlet duct is connected to the inlet fluid of the first centrifugal air duct formed in the first connecting cover, the outlet of the first centrifugal air duct is connected to the inlet fluid of the first acceleration air duct formed in the upper smoke collecting hood, the outlet of the first acceleration air duct is connected to the inlet fluid of the second centrifugal air duct formed in the second connecting cover, the outlet of the second centrifugal air duct is connected to the inlet fluid of the second acceleration air duct formed in the lower smoke collecting hood, the outlet of the second acceleration air duct is connected to the inlet fluid of the third centrifugal air duct formed in the first connecting cover, and the outlet of the third centrifugal air duct is connected to the inlet fluid of the air outlet duct formed in the upper smoke collecting hood.

[0011] To facilitate the independence of the air ducts in each cover body, the air inlet duct and the second acceleration duct are arranged front to back and separated by a first partition, and the air inlet duct is located in front of the second acceleration duct; the first centrifugal duct and the third centrifugal duct are arranged front to back and separated by a second partition, and the first centrifugal duct is located in front of the third centrifugal duct; the first acceleration duct and the air outlet duct are arranged front to back and separated by a third partition; a fourth partition is provided in the second connecting cover, the fourth partition extends from the left end of the first acceleration duct to the left end of the first partition, and the fourth partition is in close contact with the front side wall of the upper smoke collecting hood; a fifth partition is provided at the left end of the air outlet duct, the front end of the fifth partition extends to the left end of the third partition, and the rear end of the fifth partition extends to the rear side wall of the upper smoke collecting hood.

[0012] Preferably, the fourth partition is spiral, so that the second centrifugal air duct is spiral with a large inlet and a small outlet. The design of the spiral air duct can increase the movement range of the oil fume particles while keeping the rotation radius unchanged. At the same movement speed, the centrifugal filtration time is increased. At the same time, the area of ​​the fourth partition of the spiral air duct is increased, which increases the collision probability of the oil fume particles and improves the filtration effect.

[0013] Preferably, a sixth baffle is further provided in the second connecting cover, the fourth baffle and the sixth baffle are both spiral-shaped, one end of the sixth baffle is connected to the left end of the third baffle, and the other end extends to the rear side wall of the lower smoke collecting cover;

[0014] The second centrifugal air duct is formed between the sixth partition plate and the fourth partition plate, and the distance between the sixth partition plate and the fourth partition plate is equidistant, or the cross-sectional area of ​​the second centrifugal air duct gradually decreases from the inlet to the outlet, thereby increasing the centrifugal force and improving the centrifugal filtering effect.

[0015] Preferably, the first baffles have two arranged at intervals in front and back, the air inlet duct is formed between the two first baffles, and the second acceleration ducts have two and are respectively located at the front and rear sides of the air inlet duct;

[0016] The second partition has two spaced apart front and back portions, the first centrifugal air duct is formed between the two second partitions, and the third centrifugal air duct has two portions and is respectively located at the front and rear sides of the first centrifugal air duct;

[0017] The third partition has two corresponding second partitions, the first acceleration air duct is formed between the two third partitions, and the outlet air duct has two and is formed at the front and rear sides of the first acceleration air duct respectively. A fifth partition is provided at the left end of each third partition to close the left end of the outlet air duct;

[0018] The ends of the fourth partition are connected to the left ends of the two first partitions through plates, and the second centrifugal air duct is divided into two front and rear ends by the fourth partition, and each second centrifugal air duct is fluidically connected to the corresponding second acceleration air duct. By dividing several air ducts into two, multi-channel centrifugal filtration can be achieved, and the design of the diversion part of the fourth partition allows the airflow to be divided into two accordingly, so that different initial velocities required for centrifugation can be obtained according to the characteristics of different air volumes.

[0019] Preferably, in order to facilitate the realization of centrifugal effects under different air volumes according to different air volumes, when the air volume ratio of the front and rear two first acceleration air ducts is Q1:Q2, the distance between the fourth partition and the rear third partition is M, the distance between the fourth partition and the front third partition is N, and M:N=Q1:Q2 is satisfied.

[0020] Preferably, the fan system is a double-inlet fan with front and rear air intakes, thereby fully matching the characteristics of different air volumes of the two air inlets.

[0021] In order to increase the initial velocity when entering the centrifugal air duct and improve the centrifugal efficiency, at least one accelerating air duct is in a state of having a large inlet and a small outlet.

[0022] In order to increase the initial velocity when entering the centrifugal air duct and improve the centrifugal efficiency, an accelerator is provided in at least one acceleration air duct, so that the airflow from the inlet of each acceleration air duct can be accelerated and discharged to the corresponding next centrifugal air duct, thereby further providing air acceleration power.

[0023] Preferably, each accelerating air duct is arranged horizontally, and the air will produce laminar flow during the horizontal movement. Compared with turbulent flow, laminar flow has less resistance, that is, less flow loss, so as to reduce the air volume loss during the air flow process.

[0024] Compared with the prior art, the advantages of the present invention are: by forming multiple centrifugal air ducts and acceleration air ducts, centrifugal force is used to separate the oil smoke, and the acceleration channel is used to increase the initial velocity entering the centrifugal air duct, so that the oil smoke is filtered in large quantities before entering the fan system, and the oil stains do not clog the filter, so that the range hood can maintain long-term stable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic diagram of a range hood according to a first embodiment of the present invention;

[0026] Figure 2 is a cross-sectional view of a range hood according to a first embodiment of the present invention;

[0027] Figure 3 A cross-sectional view of a range hood according to a first embodiment of the present invention (section and Figure 2 parallel);

[0028] Figure 4 It is a partial schematic diagram of the air inlet assembly of the range hood according to the first embodiment of the present invention (viewed from top to bottom);

[0029] Figure 5 It is a partial schematic diagram of the air inlet assembly of the range hood according to the first embodiment of the present invention (viewed from bottom to top);

[0030] Figure 6 A schematic diagram of an alternative embodiment of the third partition plate of the air inlet assembly of the range hood according to the first embodiment of the present invention;

[0031] Figure 7 is a partial schematic diagram of an air inlet assembly of a range hood according to a second embodiment of the present invention (viewed from top to bottom);

[0032] Figure 8 is a schematic diagram of a range hood according to a third embodiment of the present invention;

[0033] Fig. 9 A schematic diagram of a hidden air inlet assembly of a range hood according to a third embodiment of the present invention;

[0034] Fig.10It is a partial schematic diagram of an air inlet assembly of a range hood according to a third embodiment of the present invention;

[0035] Fig.11 is a cross-sectional view of a range hood according to a third embodiment of the present invention;

[0036] Fig.12 It is a partial top view of the air inlet assembly of the range hood according to the third embodiment of the present invention. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below with reference to the accompanying drawings.

[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is 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. Since the embodiments disclosed in the present invention can be set in different directions, these terms indicating directions are only for illustration and should not be regarded as limitations. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features.

[0039] Embodiment 1

[0040] See also Figure 1 to Figure 5 A range hood comprises a fan frame 1, an air inlet assembly 2 arranged under the fan frame 1, and a fan system 3 arranged in the fan frame 1.

[0041] The air inlet assembly 2 includes an upper smoke hood 21 and a lower smoke hood 22 disposed below the upper smoke hood 21. The upper smoke hood 21 and the lower smoke hood 22 are both in the shape of a flat rectangular parallelepiped (the height is much smaller than the length and width), and extend in the left and right directions. The right ends of the upper smoke hood 21 and the lower smoke hood 22 are connected and fluidly connected by a first connecting hood 23, and the left ends of the upper smoke hood 21 and the lower smoke hood 22 are connected and fluidly connected by a second connecting hood 24. The upper smoke hood 21, the lower smoke hood 22, the first connecting hood 23, and the second connecting hood 24 are all hollow hood bodies, so that an air duct can be formed in the hood body. Among them, the first connecting hood 23 and the second connecting hood 24 are both in the shape of a semicircular ring or an arc, and protrude in the direction away from each other, that is, the first connecting hood 23 protrudes toward the right side, and the second connecting hood 24 protrudes toward the left side.

[0042] An air inlet 25 is formed on the lower surface of the lower smoke collecting hood 22 , and a filter screen 26 is disposed at the air inlet 25 .

[0043] An air inlet duct Q1 is formed inside the lower smoke collecting hood 22, and the left end of the air inlet duct Q1 is closed near the first connecting hood 23. The right end of the air inlet duct Q1 is connected to the inlet fluid of the first centrifugal duct Q2 formed in the first connecting hood 23 as an outlet, and the outlet of the first centrifugal duct Q2 is connected to the inlet fluid of the first acceleration duct Q3 formed in the upper smoke collecting hood 21. The outlet of the first acceleration duct Q3 is connected to the inlet fluid of the second centrifugal duct Q4 formed in the second connecting hood 24. The outlet of the second centrifugal duct Q4 is connected to the inlet fluid of the second acceleration duct Q5 formed in the lower smoke collecting hood 22, and the outlet of the second acceleration duct Q5 is connected to the inlet fluid of the third centrifugal duct Q6 formed in the first connecting hood 23. The outlet of the third centrifugal duct Q6 is connected to the inlet fluid of the outlet duct Q7 formed in the upper smoke collecting hood 21, and the outlet duct Q7 is connected to the fluid in the fan frame 1.

[0044] The centrifugal air ducts are semicircular or arc-shaped, so that the oil smoke can be centrifuged when passing through.

[0045] The air inlet 25 is only fluidly connected to the air inlet duct Q1. After the oil fume airflow enters the air inlet duct Q1 from the air inlet 25, it passes through the first centrifugal duct Q2, the first acceleration duct Q3, the second centrifugal duct Q4, the second acceleration duct Q5, and the third centrifugal duct Q6 in sequence, and then flows into the fan frame 1 through the air outlet duct Q7, and is discharged to the outside of the range hood through the fan system 3.

[0046] Among them, the air inlet duct Q1 and the second acceleration duct Q5 are arranged front and back, and the two are separated by the first partition 271, and the air inlet duct Q1 is located in front of the second acceleration duct Q5. The first centrifugal duct Q2 and the third centrifugal duct Q6 are arranged front and back, and the two are separated by the second partition 272. The first centrifugal duct Q2 is located in front of the third centrifugal duct Q6. The first partition 271 and the second partition 272 are connected or integrated. The first acceleration duct Q3 and the air outlet duct Q7 are arranged front and back, and the two are separated by the third partition 273. The first acceleration duct Q3 is located in front of the air outlet duct Q7. The second partition 272 and the third partition 273 are connected or integrated. A fourth partition 274 is provided in the second connection cover 24. The fourth partition 274 extends from the left end of the first acceleration duct Q3 to the left end of the first partition 271, and the fourth partition 274 is in close contact with the front side wall of the upper smoke collecting cover 21. Thus, the fourth partition plate 274 is spiral, so that the second centrifugal air duct Q4 is spiral with a large inlet and a small outlet. A fifth partition plate 275 is provided at the left end of the air outlet duct Q7 (the transition position between the upper smoke collecting hood 21 and the second connecting hood 24), and the front end of the fifth partition plate 275 extends to the left end of the third partition plate 273, and the rear end of the fifth partition plate 275 extends to the rear wall of the upper smoke collecting hood 21.

[0047] Each accelerating air duct is set horizontally, and the air will produce laminar flow during horizontal movement. Compared with turbulent flow, laminar flow has less resistance, that is, less flow loss, so as to reduce the air volume loss during air flow. The design of the spiral air duct can increase the movement range of oil fume particles under the premise of unchanged rotation radius, that is, increase the centrifugal filtration time at the same movement speed, and at the same time, the area of ​​the fourth partition 274 of the spiral air duct is increased, that is, the collision probability of oil fume particles is increased, and the filtering effect is improved.

[0048] See also Figure 6 The cross section of the third partition plate 273 can also be triangular, so that the cross section of the first accelerating air duct Q3 is in a state of large inlet and small outlet. Similarly, the first partition plate 271 can also be triangular, so that the cross section of the second accelerating air duct Q5 is in a state of large inlet and small outlet.

[0049] The design intention of the above large inlet and small outlet is: according to the fluid continuity equation, Q = S*V, where Q is the air volume, S is the cross-sectional area, and V is the wind speed. In other words, when the air volume Q remains unchanged, that is, when the gear of the range hood does not change, the cross-sectional area S is inversely proportional to the wind speed V, that is, as the cross-sectional area S decreases, the wind speed V gradually increases. Until the end of the acceleration duct, the wind speed V is the largest, at which time the oil smoke is about to enter the centrifugal duct, that is, when the oil smoke enters the centrifugal duct, the initial velocity V is the largest.

[0050] According to the centripetal force equation: F = M*V2 / R. In the present invention, when the mass of the oil fume particles is greater than the mass of the air, the centripetal forces required for the two are different, that is, the oil fume particles with a larger mass are more likely to be centrifugal. As mentioned above, when the oil fume enters the centrifugal air duct, the initial velocity V is the largest. At this time, the force on the oil fume particles is not enough to provide the centripetal force for circular motion, and the centrifugal phenomenon of the oil fume particles is aggravated, that is, the oil fume particles are centrifugal at this time.

[0051] See also Figure 4 and Figure 5 The first accelerating air duct Q3 and the second accelerating air duct Q5 are respectively provided with accelerators 28, preferably cross-flow fans, which accelerate the airflow from the inlet of each accelerating air duct and discharge it to the corresponding next centrifugal air duct, thereby further providing air acceleration power, that is, increasing the initial velocity V before centrifugation.

[0052] By setting three centrifugal air ducts, i.e. triple centrifugal filtration, the oil fume gas has been filtered to a great extent before reaching the fan system 3. When the oil fume is sucked into the range hood, it will first converge in the air inlet duct Q1, and then enter the first centrifugal duct Q2, at which time the large oil fume particles are centrifugally filtered, and then the oil fume particles enter the first acceleration duct Q3, where the wind speed is increased, and then enter the second centrifugal duct Q4. Due to the large initial velocity, the large oil fume particles are further centrifugally filtered in the second centrifugal duct Q4, and then enter the second acceleration duct Q5, at which time the oil fume air speed is further accelerated, and then enter the third centrifugal duct Q6, where the small oil fume particles are centrifugally filtered. Finally, it enters the fan frame 1 through the outlet duct Q7.

[0053] There are at least three centrifugal air ducts. By arranging the number and manner of the partitions, centrifugal air ducts with multiple paths can be formed, that is, multiple centrifugal filtration can be achieved. The number of centrifugal air ducts is 2n+1, where n is a natural number.

[0054] The above-mentioned “cross-sectional area” refers to the area of ​​the longitudinal section of each acceleration air duct or the cross-sectional area of ​​each centrifugal air duct.

[0055] Embodiment 2

[0056] See also Figure 7 In this embodiment, the difference from the above-mentioned embodiment 1 is that a sixth partition plate 276 is further provided in the second connecting cover 24. The sixth partition plate 276 is spiral-shaped, and one end of the sixth partition plate 276 is connected to the left end of the third partition plate 273, and the other end extends to the rear side wall of the lower smoke collecting cover 22.

[0057] The second centrifugal air duct Q4 is formed between the sixth partition plate 276 and the fourth partition plate 274, and the distance between the sixth partition plate 276 and the fourth partition plate 274 is equidistant, or the cross-sectional area of ​​the second centrifugal air duct Q4 gradually decreases from the inlet to the outlet. When the distance is equidistant, the cross-sectional area of ​​the second centrifugal air duct Q4 is equal. According to the fluid continuity equation, the wind speed during the centrifugal process is equal to the initial velocity when entering the inlet. As long as the initial velocity is ensured, the centrifugation of the corresponding oil fume particles can be achieved. When the cross-sectional area gradually decreases from the inlet to the outlet, that is, the cross-sectional area gradually decreases, according to the fluid continuity equation Q=S*V, when the flow rate remains unchanged, the cross-sectional area decreases and the speed increases. That is, the velocity V of the fluid gradually increases in the second centrifugal air duct Q4 until it is the maximum at the outlet. The process of increasing speed will increase the centrifugal force, that is, the oil fume particles will be more easily centrifuged, and oil fume particles of different mass sizes can be filtered in the second centrifugal air duct Q4.

[0058] Embodiment 3

[0059] See also Figure 8 to Figure 11 In this embodiment, the difference from the above-mentioned embodiment 1 is that the first partition plate 271 has two spaced apart front and back, the air inlet duct Q1 is formed between the two first partition plates 271, and the second acceleration duct Q5 has two, which are respectively located on the front and back sides of the air inlet duct Q1. Correspondingly, the second partition plate 272 has two spaced apart front and back, the first centrifugal duct Q2 is formed between the two second partition plates 272, and the third centrifugal duct Q6 has two, which are respectively located on the front and back sides of the first centrifugal duct Q2. The third partition plate 273 has two corresponding to the second partition plate 272, the first acceleration duct Q3 is formed between the two third partition plates 273, and the air outlet duct Q7 has two, which are respectively formed on the front and back sides of the first acceleration duct Q3. A fifth partition plate 275 is provided at the left end of each third partition plate 273 to close the left end of the air outlet duct Q7. The fourth partition plate 274 is no longer in close contact with the wall surface of the upper smoke collecting hood 21, and one end thereof corresponds to the position between the two third partition plates 273. The ends of the fourth partition plate 274 can be connected to the left ends of the two first partition plates 271 through plates. The second centrifugal air duct Q4 is thus divided into two front and rear parts by the fourth partition plate 274, and each second centrifugal air duct Q4 is fluidically connected to the corresponding second acceleration air duct Q5. The oil smoke airflow is accelerated in the first acceleration air duct Q3, and then separated into two parts by the fourth partition plate 274, respectively entering the second centrifugal air duct Q4 on the front side and the second centrifugal air duct Q4 on the rear side. The centrifugal and acceleration processes are the same as those in the first embodiment.

[0060] An accelerator 28 is arranged in each accelerating air duct.

[0061] By dividing each of the above-mentioned air ducts into two, multi-channel centrifugal filtration is achieved. It is particularly suitable for the fan system 3 to be in the form of front and rear air intake, which can match the front and rear air inlets of the fan system 3 to inhale different air volumes (because one side of the double-inlet centrifugal fan is usually provided with a drive motor, the drive motor will hinder the air intake, which can match the characteristics of the front and rear air inlet of the front and rear air inlet fan system to inhale different air volumes. Through the design of the diversion part of the fourth partition 274, the airflow can be divided into two accordingly, and through the control of each accelerator, according to the characteristics of different air volumes, it can obtain different initial velocities required for centrifugation.

[0062] The third partition plate 273 may preferably be arranged in such a way that the cross-sectional area of ​​the first accelerating air duct Q3 has the characteristics of a large inlet and a small outlet.

[0063] In the embodiment, the centrifugal effect under different air volumes can be achieved according to different air volumes. For example, when the air volume ratio of the two first acceleration air ducts Q3 is Q1:Q2, see Fig.12 The distance between the fourth partition 274 and the third partition 273 on the rear side is M, the distance between the fourth partition 274 and the third partition 273 on the front side is N, and M:N=Q1:Q2 is satisfied. At this time, the ventilation effect is the best and the filtering effect is also the best.

[0064] The "fluid connection" referred to in the present invention refers to the spatial position relationship between two parts or parts (hereinafter collectively referred to as the first part and the second part respectively), that is, the fluid (gas, liquid or a mixture of the two) can flow from the first part along the flow path or / and be transported to the second part. The first part and the second part can be directly connected, or the first part and the second part can be indirectly connected through at least one third party. The third party can be a fluid channel such as a pipe, channel, duct, guide member, hole, groove, etc., or it can be a chamber allowing fluid to flow through, or a combination of the above.

Claims

1. A range hood, comprising a fan frame (1), an air inlet assembly (2) arranged below the fan frame (1), and a fan system (3) arranged in the fan frame (1); characterized in that: The air inlet assembly (2) comprises an upper smoke collecting hood (21) and a lower smoke collecting hood (22) arranged below the upper smoke collecting hood (21); the right side ends of the upper smoke collecting hood (21) and the lower smoke collecting hood (22) are connected and fluidically communicated via a first connecting hood (23); the left side ends of the upper smoke collecting hood (21) and the lower smoke collecting hood (22) are connected and fluidically communicated via a second connecting hood (24); the first connecting hood (23) and the second connecting hood (24) are both semicircular or arc-shaped and protrude in directions away from each other; an air inlet (25) is provided on the lower surface of the lower smoke collecting hood (22); The upper smoke collecting hood (21), the lower smoke collecting hood (22), the first connecting hood (23) and the second connecting hood (24) are all hollow hood bodies; an air inlet duct (Q1) is formed in the lower smoke collecting hood (22); an air outlet duct (Q7) in fluid communication with the interior of the fan frame (1) is formed in the upper smoke collecting hood (21); and the air inlet (25) is only in fluid communication with the air inlet duct (Q1); The upper smoke collecting hood (21) and the lower smoke collecting hood (22) are both formed with acceleration air ducts, and the first connecting hood (23) and the second connecting hood (24) are both formed with semicircular or arc-shaped centrifugal air ducts, and the oil smoke airflow at least passes through the first connecting hood (23), the upper smoke collecting hood (21), the second connecting hood (24), the lower smoke collecting hood (22), and the air ducts connected in sequence in the first connecting hood (23), and then is discharged into the fan frame (1) from the air outlet duct (Q7); The air inlet duct (Q1) is closed at the left end portion near the first connecting cover (23), and the right end portion of the air inlet duct (Q1) is connected to the inlet fluid of the first centrifugal duct (Q2) formed in the first connecting cover (23); the outlet of the first centrifugal duct (Q2) is connected to the inlet fluid of the first accelerating duct (Q3) formed in the upper smoke collecting cover (21); the outlet of the first accelerating duct (Q3) is connected to the inlet fluid of the second centrifugal duct (Q4) formed in the second connecting cover (24); the outlet of the second centrifugal duct (Q4) is connected to the inlet fluid of the second accelerating duct (Q5) formed in the lower smoke collecting cover (22); the outlet of the second accelerating duct (Q5) is connected to the inlet fluid of the third centrifugal duct (Q6) formed in the first connecting cover (23); and the outlet of the third centrifugal duct (Q6) is connected to the inlet fluid of the air outlet duct (Q7) formed in the upper smoke collecting cover (21).

2. The range hood according to claim 1, characterized in that: The air inlet duct (Q1) and the second accelerating air duct (Q5) are arranged front and back and are separated by a first partition (271), and the air inlet duct (Q1) is located in front of the second accelerating air duct (Q5); the first centrifugal air duct (Q2) and the third centrifugal air duct (Q6) are arranged front and back and are separated by a second partition (272), and the first centrifugal air duct (Q2) is located in front of the third centrifugal air duct (Q6); the first accelerating air duct (Q3) and the air outlet duct (Q7) are arranged front and back and are separated by a third partition (273); A fourth partition (274) is provided in the second connecting cover (24), and the fourth partition (274) extends from the left end of the first accelerating air duct (Q3) to the left end of the first partition (271), and the fourth partition (274) is in close contact with the front side wall of the upper smoke collecting hood (21); a fifth partition (275) is provided at the left end of the air outlet duct (Q7), and the front end of the fifth partition (275) extends to the left end of the third partition (273), and the rear end of the fifth partition (275) extends to the rear side wall of the upper smoke collecting hood (21).

3. The range hood according to claim 2, characterized in that: The fourth partition plate (274) is in a spiral shape, so that the second centrifugal air duct (Q4) is in a spiral shape with a large inlet and a small outlet.

4. The range hood according to claim 2, characterized in that: A sixth partition (276) is also provided in the second connecting cover (24); the fourth partition (274) and the sixth partition (276) are both spiral-shaped; one end of the sixth partition (276) is connected to the left end of the third partition (273), and the other end extends to the rear side wall of the lower smoke collecting cover (22); The second centrifugal air duct (Q4) is formed between the sixth partition plate (276) and the fourth partition plate (274), and the distance between the sixth partition plate (276) and the fourth partition plate (274) is equidistant, or the cross-sectional area of ​​the second centrifugal air duct (Q4) gradually decreases from the inlet to the outlet.

5. The range hood according to claim 2, characterized in that: The first partition plates (271) have two spaced apart arrangement in the front and rear, the air inlet duct (Q1) is formed between the two first partition plates (271), and the second acceleration ducts (Q5) have two and are respectively located at the front and rear sides of the air inlet duct (Q1); The second partition plates (272) have two arranged at intervals in front and back, the first centrifugal air duct (Q2) is formed between the two second partition plates (272), and the third centrifugal air ducts (Q6) have two and are respectively located at the front and rear sides of the first centrifugal air duct (Q2); The third partition plates (273) have two corresponding ones to the second partition plates (272); the first accelerating air duct (Q3) is formed between the two third partition plates (273); the air outlet duct (Q7) has two and is respectively formed on the front and rear sides of the first accelerating air duct (Q3); a fifth partition plate (275) is provided at the left end of each third partition plate (273) to close the left end of the air outlet duct (Q7); The ends of the fourth partition (274) are respectively connected to the left ends of the two first partitions (271) through plates, and the second centrifugal air duct (Q4) is thus divided into two front and rear parts by the fourth partition (274), and each second centrifugal air duct (Q4) is fluidically connected to the corresponding second acceleration air duct (Q5).

6. The range hood according to claim 5, characterized in that: When the air volume ratio of the front and rear first acceleration air ducts (Q3) is Q1:Q2, the distance between the fourth partition plate (274) and the rear third partition plate (273) is M, and the distance between the fourth partition plate (274) and the front third partition plate (273) is N, and M:N=Q1:Q2 is satisfied.

7. The range hood according to claim 5, characterized in that: The fan system (3) is a double-inlet fan with front and rear air intakes.

8. The range hood according to any one of claims 1 to 7, characterized in that: At least one accelerating air duct is in a state of having a large inlet and a small outlet.

9. The range hood according to any one of claims 1 to 7, characterized in that: An accelerator (28) is arranged in at least one accelerating air duct.

10. The range hood according to any one of claims 1 to 7, characterized in that: Each accelerating air duct is arranged horizontally.

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