Building ventilating duct with noise reduction structure

Abstract

The utility model relates to the technical field of building functions, in particular to a building ventilating duct with a noise reduction structure, noise reduction components are connected in the ventilating duct, each noise reduction component comprises a supporting net pipe and an aluminum silicate cotton pipe, a plurality of noise reduction components are arranged in the ventilating duct and are linearly and uniformly distributed along the length direction of the ventilating duct, and the supporting net pipes are connected with the aluminum silicate cotton pipes. Noise reduction cotton or sound absorption cotton is not used for being directly connected into the ventilation pipeline, the multiple noise reduction assemblies are arranged in the ventilation pipeline, and supporting net pipes of the multiple noise reduction assemblies are supported in the ventilation pipeline in the length direction of the ventilation pipeline. The supporting net pipe and the aluminum silicate cotton pipe are not connected with the inner wall of the ventilation pipeline, after dust is accumulated on the aluminum silicate cotton pipe after long-time use, the whole noise reduction assembly can be taken out to be cleaned or replaced, and the vibration assembly can conduct targeted dust removal on different positions of the ventilation pipeline, so that the noise reduction effect is guaranteed, and the replacement or clear frequency of the noise reduction assembly is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of building functions, in particular to a building ventilation duct with a noise reduction structure. Background Art

[0002] Ventilation ducts are frequently used components in industrial and civil buildings. They are a common municipal infrastructure that allows air to circulate inside buildings and reduces the concentration of harmful gases. During the construction of a building, space is generally reserved for the installation of ventilation ducts. When constructing ventilation ducts, metal pipes or composite pipes are used and installed in the reserved space.

[0003] When the existing ventilation duct is in use, noise is often generated due to the rapid flow of air. The general noise reduction method is to install noise reduction cotton or sound-absorbing cotton inside the ventilation duct for noise reduction. However, in actual use, there will be a lot of dust in it, which will block the sound-absorbing holes and affect the noise reduction of the ventilation duct. The noise reduction effect is getting worse and worse, and the noise reduction components inside the ventilation duct cannot be disassembled and are not easy to carry out subsequent processing. Utility Model Content

[0004] The utility model aims to provide a building ventilation duct with a noise reduction structure, so as to solve the problems in the prior art that dust inside the ventilation duct affects the noise reduction effect of the ventilation duct and the noise reduction components inside the ventilation duct cannot be disassembled and are difficult to be subsequently processed.

[0005] In order to solve the above-mentioned technical problems, the utility model discloses a building ventilation duct with a noise reduction structure, including an air inlet duct fixedly connected to the upper side wall of the ventilation duct, an air outlet duct fixedly connected to the lower side wall of the ventilation duct, a noise reduction component is connected inside the ventilation duct, the noise reduction component includes a supporting mesh tube and an aluminum silicate wool tube, the aluminum silicate wool tube is sleeved on the outside of the supporting mesh tube, a plurality of noise reduction components are arranged inside the ventilation duct, the plurality of noise reduction components are linearly evenly distributed along the length direction of the ventilation duct, and the supporting mesh tube is provided with evenly distributed mesh holes.

[0006] Furthermore, the supporting network pipe includes a main pipe, a bottom pipe and a ring plate, the ring plate is arranged on the top surface of the bottom pipe, the main pipe is arranged on the top surface of the ring plate, the inner diameter of the bottom pipe is greater than the outer diameter of the main pipe, the outer diameter of the bottom pipe is greater than the outer diameter of the main pipe, the outer diameter of the ring plate is equal to the outer diameter of the bottom pipe, and the inner diameter of the ring plate is equal to the inner diameter of the main pipe; in two adjacent noise reduction components among the multiple noise reduction components, the bottom pipe of one main pipe is sleeved on the top of the other main pipe; the aluminum silicate wool tube is sleeved on the outer wall of the main pipe, and the lower end of the aluminum silicate wool tube is connected to the ring plate.

[0007] Furthermore, a top cover is connected to the top of the ventilation duct, and the top cover includes a top plate and a sleeve I. The sleeve I is fixedly connected to the bottom surface of the top plate, and the sleeve I is sleeved on the top of the ventilation duct. A plurality of screw holes I are provided on the sleeve I, and the axes of the plurality of screw holes I are linearly evenly distributed with the axis of the sleeve I as the center. Bolts are connected to the plurality of screw holes I, and the bolts pass through the screw holes I and are connected to the outer wall of the ventilation duct.

[0008] Furthermore, the bottom end of the ventilation duct is connected to a bottom cover, which includes a bottom plate and a sleeve II. The sleeve II is fixedly connected to the top surface of the bottom plate, and the sleeve II is sleeved on the bottom end of the ventilation duct. A plurality of screw holes II are provided on the sleeve II, and the axes of the plurality of screw holes II are linearly evenly distributed with the axis of the sleeve II as the center. Bolts are connected to the plurality of screw holes II, and the bolts pass through the screw holes II and are connected to the outer wall of the ventilation duct. The lower end of the bottom pipe of the plurality of noise reduction components closest to the bottom cover is connected to the top surface of the bottom plate.

[0009] Furthermore, the top cover is connected with sound-absorbing cotton, and the sound-absorbing cotton is connected between the top plate and the ventilation duct.

[0010] Furthermore, it includes a vibration component, which includes a support block, a cylinder I, a fixed seat, a vibration plate, a vibration block, a vibration motor and a cylinder II. The support block is fixedly connected to the outer wall of the ventilation duct, the support block is arranged on the upper part of the ventilation duct, the cylinder I is fixedly connected to the bottom surface of the support block, the cylinder I is arranged outside the ventilation duct, the piston rod of the cylinder I extends downward, the fixed seat is fixedly connected to the piston rod of the cylinder I, the cylinder II is fixedly connected to the fixed seat, the piston rod of the cylinder II is arranged toward the ventilation duct, the vibration plate is fixedly connected to the piston rod of the cylinder II, the vibration motor is fixedly connected to the rear side of the vibration plate, the vibration block is fixedly connected to the front side of the vibration plate away from the vibration motor, and the vibration block is top-connected to the outer wall of the ventilation duct.

[0011] Furthermore, there are two cylinders II, and the vibration motor is arranged between the two cylinders II.

[0012] Furthermore, the base plate is provided with a through hole, the inner diameter of the through hole is smaller than the inner diameter of the base tube, a blind plate is connected to the bottom surface of the base plate, the blind plate closes the through hole, the blind plate is fixed to the base plate by bolts, and a threaded blind hole for bolt connection is opened on the bottom surface of the base plate.

[0013] Furthermore, two support shafts are fixedly connected to the outer wall of the ventilation duct, and the two support shafts are both arranged at the lower part of the ventilation duct. The two support shafts are symmetrical, and connecting rods are rotatably connected to the support shafts. The bottom ends of the two connecting rods away from the support shafts are fixedly connected to the collection box. The collection box is a box body with an open top surface. The collection box is arranged under the bottom cover, and the top surface opening of the collection box faces the bottom cover. The inner diameter of the collection box is larger than the inner diameter of the ventilation duct.

[0014] The beneficial effects of the utility model are as follows: the utility model does not use noise reduction cotton or sound absorbing cotton to be directly connected to the inside of the ventilation duct, but rather multiple noise reduction components are arranged inside the ventilation duct, and the supporting mesh pipes of the multiple noise reduction components are supported inside the ventilation duct along the length direction of the ventilation duct, and the supporting mesh pipes and the aluminum silicate wool pipes are not connected to the inner wall of the ventilation duct. When dust accumulates on the aluminum silicate wool pipes after a long period of use, the noise reduction components can be taken out as a whole for cleaning or replacement, thereby ensuring the noise reduction effect;

[0015] In the utility model, the main pipe is arranged on the top surface of the ring plate, the inner diameter of the bottom pipe is larger than the outer diameter of the main pipe, the outer diameter of the bottom pipe is larger than the outer diameter of the main pipe, the outer diameter of the ring plate is equal to the outer diameter of the bottom pipe, and the inner diameter of the ring plate is equal to the inner diameter of the main pipe. Through the above structure, multiple main pipes can be connected end to end at one time, and at the same time, the aluminum silicate wool pipe is supported, the loading and unloading is simple and convenient, and the connection stability is strong.

[0016] The utility model is provided with a vibration component, which can carry out targeted dust removal at different positions of the ventilation duct. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the utility model;

[0018] Figure 2 For this utility model Figure 1 AA section view;

[0019] Figure 3 For this utility model Figure 1 BB cross-sectional view;

[0020] Figure 4 This is a schematic diagram of the structure of the noise reduction component of the utility model;

[0021] Figure 5 It is a schematic diagram of the structure of the top cover of the utility model;

[0022] Figure 6 It is a structural schematic diagram of the bottom cover of the utility model.

[0023] In the figure: 1. air inlet duct; 2. air outlet duct; 3. ventilation duct; 4. top cover; 401. top plate; 402. casing Ⅰ; 403. screw hole Ⅰ; 5. sound-absorbing cotton; 6. bottom cover; 603. bottom plate; 602. casing Ⅱ; 603. screw hole Ⅱ; 604. through hole; 605. blind plate; 7. collecting box; 8. supporting shaft; 9. connecting rod; 10. noise reduction component; 11. supporting mesh pipe; 1101. main pipe; 1102. bottom pipe; 1103. ring plate; 12. aluminum silicate cotton tube; 13. vibration component; 14. supporting block; 15. cylinder Ⅰ; 16. fixing seat; 17. vibration plate; 18. vibration block; 19. vibration motor; 20. cylinder Ⅱ. DETAILED DESCRIPTION

[0024] like Figure 1-Figure 4 As shown, the utility model is a building ventilation duct with a noise reduction structure, including an air inlet duct 1 fixedly connected to the upper side wall of the ventilation duct 3, an air outlet duct 2 fixedly connected to the lower side wall of the ventilation duct 3, a noise reduction component 10 is connected inside the ventilation duct 3, the noise reduction component 10 includes a supporting mesh tube 11 and an aluminum silicate wool tube 12, the aluminum silicate wool tube 12 is sleeved on the outside of the supporting mesh tube 11, a plurality of noise reduction components 10 are arranged inside the ventilation duct 3, and the plurality of noise reduction components 10 are linearly evenly distributed along the length direction of the ventilation duct 3, and the supporting mesh tube 11 is provided with evenly distributed mesh holes; the supporting mesh tube 11 includes a main The pipe 1101, the bottom pipe 1102 and the ring plate 1103, the ring plate 1103 is arranged on the top surface of the bottom pipe 1102, the main pipe 1101 is arranged on the top surface of the ring plate 1103, the inner diameter of the bottom pipe 1102 is greater than the outer diameter of the main pipe 1101, the outer diameter of the bottom pipe 1102 is greater than the outer diameter of the main pipe 1101, the outer diameter of the ring plate 1103 is equal to the outer diameter of the bottom pipe 1102, and the inner diameter of the ring plate 1103 is equal to the inner diameter of the main pipe 1101; in two adjacent noise reduction components 10 of the multiple noise reduction components 10, the bottom pipe 1102 of one main pipe 1101 is sleeved on the top of the other main pipe 1101; the aluminum silicate wool pipe 12 is sleeved on the outer of the main pipe 1101 The lower end of the aluminum silicate wool tube 12 is connected to the ring plate 1103; the top of the ventilation duct 3 is connected to a top cover 4, which includes a top plate 401 and a sleeve Ⅰ402, the sleeve Ⅰ402 is fixedly connected to the bottom surface of the top plate 401, the sleeve Ⅰ402 is sleeved on the top of the ventilation duct 3, and a plurality of screw holes Ⅰ403 are provided on the sleeve Ⅰ402, and the axes of the plurality of screw holes Ⅰ403 are linearly uniformly distributed with the axis of the sleeve Ⅰ402 as the center, and bolts are connected in the plurality of screw holes Ⅰ403, and the bolts pass through the screw holes Ⅰ403 and are connected to the outer wall of the ventilation duct 3; the bottom end of the ventilation duct 3 is connected to a bottom cover 6, and the bottom cover 6 includes a bottom plate 6 01 and sleeve II 602, sleeve II 602 is fixedly connected to the top surface of the base plate 601, sleeve II 602 is sleeved on the bottom end of the ventilation duct 3, a plurality of screw holes II 603 are provided on the sleeve II 602, the axes of the plurality of screw holes II 603 are linearly evenly distributed with the axis of the sleeve II 602 as the center, bolts are connected in the plurality of screw holes II 603, the bolts pass through the screw holes II 603 and are connected to the outer wall of the ventilation duct 3, the lower end of the bottom pipe 1102 closest to the bottom cover 6 among the plurality of noise reduction components 10 is connected to the top surface of the base plate 601; sound-absorbing cotton 5 is connected in the top cover 4, and the sound-absorbing cotton 5 is connected between the top plate 401 and the ventilation duct 3.

[0025] The utility model does not use noise reduction cotton or sound absorbing cotton to be directly connected to the inside of the ventilation duct 3, but arranges multiple noise reduction components 10 inside the ventilation duct 3, the noise reduction components 10 include a supporting mesh tube 11 and an aluminum silicate wool tube 12, the supporting mesh tube 11 is used to support the aluminum silicate wool tube 12, the aluminum silicate wool tube 12 is used for noise reduction, the supporting mesh tube 11 of the multiple noise reduction components 10 is supported inside the ventilation duct 3 along the length direction of the ventilation duct 3, the supporting mesh tube 11 and the aluminum silicate wool tube 12 are not connected to the inner wall of the ventilation duct 3, when dust accumulates on the aluminum silicate wool tube 12 after a long period of use, the noise reduction components 10 can be taken out as a whole for cleaning or replacement, thereby ensuring the noise reduction effect.

[0026] The top cover 4 and the bottom cover 6 block the unused interfaces of the ventilation duct 3. At the same time, the bottom cover 6 supports the noise reduction component 10. In actual use, the top cover 4 and the bottom cover 6 are set at appropriate positions according to the actual situation on site, or the top cover 4 and the bottom cover 6 are removed and connected to other pipelines or used as air outlets. It should be noted that when the bottom cover 6 needs to be removed, a flange-shaped support ring can be considered to be set here to support the noise reduction component 10.

[0027] This embodiment is described with respect to a ventilation duct 3 with a vertically arranged rectangular cross-section. When the ventilation duct 3 is arranged horizontally or a ventilation duct 3 with other cross-sectional shapes is used, it does not affect the use of the utility model. It is only necessary to flexibly arrange the air inlet duct 1, the air outlet duct 2, the top cover 4 and the bottom cover 6 according to the use requirements.

[0028] In the utility model, the main pipe 1101 is arranged on the top surface of the ring plate 1103, the inner diameter of the bottom pipe 1102 is larger than the outer diameter of the main pipe 1101, the outer diameter of the bottom pipe 1102 is larger than the outer diameter of the main pipe 1101, the outer diameter of the ring plate 1103 is equal to the outer diameter of the bottom pipe 1102, and the inner diameter of the ring plate 1103 is equal to the inner diameter of the main pipe 1101. Through the above structure, multiple main pipes 1101 can be connected end to end at one time, and at the same time, the aluminum silicate wool tube 12 is supported.

[0029] The utility model also includes a vibration assembly 13, the vibration assembly 13 includes a support block 14, a cylinder I 15, a fixed seat 16, a vibration plate 17, a vibration block 18, a vibration motor 19 and a cylinder II 20, the support block 14 is fixedly connected to the outer wall of the ventilation duct 3, the support block 14 is arranged on the upper part of the ventilation duct 3, the cylinder I 15 is fixedly connected to the bottom surface of the support block 14, the cylinder I 15 is arranged outside the ventilation duct 3, the piston rod of the cylinder I 15 extends downward, and the fixed seat 16 is fixedly connected On the piston rod of cylinder Ⅰ15, cylinder Ⅱ20 is fixedly connected to the fixing seat 16, the piston rod of cylinder Ⅱ20 is arranged toward the ventilation duct 3, the vibration plate 17 is fixedly connected to the piston rod of cylinder Ⅱ20, the vibration motor 19 is fixedly connected to the rear side of the vibration plate 17, the vibration block 18 is fixedly connected to the front side of the vibration plate 17 away from the vibration motor 19, and the vibration block 18 is connected to the outer wall of the ventilation duct 3; two cylinders Ⅱ20 are provided, and the vibration motor 19 is arranged between the two cylinders Ⅱ20.

[0030] The setting of the vibration component 13 can realize vibration dust removal of the ventilation duct 3 and the noise reduction component 10, thereby ensuring the noise reduction effect of the noise reduction component 10. The extension and retraction of cylinder I 15 drives the fixed seat 16 to move along the length direction of the ventilation duct 3 to realize vibration dust removal at different positions of the ventilation duct 3. Cylinder II 20 extends to drive the vibration plate 17, the vibration block 18 and the vibration motor 19 to move toward the ventilation duct 3. When the vibration block 18 is against the outer wall of the ventilation duct 3, cylinder II 20 stops and the vibration motor 19 starts to vibrate and dust remove the ventilation duct 3 and the noise reduction component 10. After the vibration dust removal is completed, the vibration motor 19 stops, and cylinder II 20 starts to drive the vibration plate 17, the vibration block 18 and the vibration motor 19 to leave the ventilation duct 3. Cylinder I 15 starts to move the fixed seat 16 to other positions for vibration dust removal.

[0031] The arrangement of the two cylinders II 20 ensures the structural stability of the vibration plate 17 .

[0032] It is recommended that the vibration block 18 be made of materials such as hard rubber to prevent the vibration plate 17 from colliding with the ventilation duct 3 and damaging the outer wall of the ventilation duct 3 during vibration dust removal.

[0033] A through hole 604 is provided on the bottom plate 601, and the inner diameter of the through hole 604 is smaller than the inner diameter of the bottom tube 1102. A blind plate 605 is connected to the bottom surface of the bottom plate 601, and the blind plate 605 closes the through hole 604. The blind plate 605 is fixed to the bottom plate 601 by bolts, and a threaded blind hole for bolt connection is opened on the bottom surface of the bottom plate 601.

[0034] A through hole 604 is set on the bottom plate 601 and a blind plate 605 is connected, so that the bottom plate 601 forms a flange structure. After removing the blind plate 605, the dust inside the ventilation duct 3 is cleaned. Because the inner diameter of the through hole 604 is smaller than the inner diameter of the bottom pipe 1102, the support for the noise reduction component 10 will not be damaged after the blind plate 605 is removed. The blind plate can also be replaced with a lifted pipe according to actual usage.

[0035] Two support shafts 8 are fixedly connected to the outer wall of the ventilation duct 3. The two support shafts 8 are both arranged at the lower part of the ventilation duct 3. The two support shafts 8 are symmetrical. Connecting rods 9 are rotatably connected to the support shafts 8. The bottom ends of the two connecting rods 9 away from the support shafts 8 are fixedly connected to the collection box 7. The collection box 7 is a box body with an open top surface. The collection box 7 is arranged under the bottom cover 6. The top surface opening of the collection box 7 faces the bottom cover 6. The inner diameter of the collection box 7 is larger than the inner diameter of the ventilation duct 3.

[0036] The collecting box 7 is used to receive dust dropped from the through hole 604. The connecting rod 9 is rotatably connected to the supporting shaft 8. When the noise reduction component 10 is disassembled, the collecting box 7 is rotated to make room for disassembly.

Claims

1. A building ventilation duct with a noise reduction structure, wherein an air inlet duct (1) is fixedly connected to the upper side wall of the ventilation duct (3), and an air outlet duct (2) is fixedly connected to the lower side wall of the ventilation duct (3), characterized in that: The ventilation duct (3) is internally connected to a noise reduction component (10), the noise reduction component (10) comprising a supporting mesh tube (11) and an aluminum silicate wool tube (12), the aluminum silicate wool tube (12) being sleeved on the outside of the supporting mesh tube (11), a plurality of noise reduction components (10) are arranged inside the ventilation duct (3), the plurality of noise reduction components (10) are linearly evenly distributed along the length direction of the ventilation duct (3), and the supporting mesh tube (11) is provided with evenly distributed mesh holes.

2. A building ventilation duct with a noise reduction structure according to claim 1, characterized in that: The supporting network pipe (11) comprises a main pipe (1101), a bottom pipe (1102) and a ring plate (1103), wherein the ring plate (1103) is arranged on the top surface of the bottom pipe (1102), and the main pipe (1101) is arranged on the top surface of the ring plate (1103), the inner diameter of the bottom pipe (1102) is greater than the outer diameter of the main pipe (1101), the outer diameter of the bottom pipe (1102) is greater than the outer diameter of the main pipe (1101), and the outer diameter of the ring plate (1103) is equal to The outer diameter of the bottom pipe (1102) and the inner diameter of the ring plate (1103) are equal to the inner diameter of the main pipe (1101); in two adjacent noise reduction assemblies (10) among the plurality of noise reduction assemblies (10), the bottom pipe (1102) of one main pipe (1101) is sleeved on the top of another main pipe (1101); the aluminum silicate wool tube (12) is sleeved on the outer wall of the main pipe (1101), and the lower end of the aluminum silicate wool tube (12) is connected to the ring plate (1103).

3. The building ventilation duct with a noise reduction structure according to claim 2, characterized in that: The top end of the ventilation duct (3) is connected to a top cover (4), the top cover (4) comprises a top plate (401) and a sleeve I (402), the sleeve I (402) is fixedly connected to the bottom surface of the top plate (401), the sleeve I (402) is sleeved on the top end of the ventilation duct (3), a plurality of screw holes I (403) are provided on the sleeve I (402), the axes of the plurality of screw holes I (403) are linearly evenly distributed with the axis of the sleeve I (402) as the center, the plurality of screw holes I (403) are connected to bolts, the bolts pass through the screw holes I (403) and are then connected to the outer wall of the ventilation duct (3).

4. The building ventilation duct with a noise reduction structure according to claim 3, characterized in that: The bottom end of the ventilation duct (3) is connected to a bottom cover (6), the bottom cover (6) comprises a bottom plate (601) and a sleeve II (602), the sleeve II (602) is fixedly connected to the top surface of the bottom plate (601), the sleeve II (602) is sleeved on the bottom end of the ventilation duct (3), a plurality of screw holes II (603) are provided on the sleeve II (602), the axes of the plurality of screw holes II (603) are linearly evenly distributed with the axis of the sleeve II (602) as the center, the plurality of screw holes II (603) are connected to bolts, the bolts pass through the screw holes II (603) and are connected to the outer wall of the ventilation duct (3), and the lower end of the bottom tube (1102) closest to the bottom cover (6) in the plurality of noise reduction components (10) is connected to the top surface of the bottom plate (601).

5. The building ventilation duct with a noise reduction structure according to claim 4, characterized in that: The top cover (4) is internally connected with sound-absorbing cotton (5), and the sound-absorbing cotton (5) is connected between the top plate (401) and the ventilation duct (3).

6. A building ventilation duct with a noise reduction structure according to any one of claims 1 to 5, characterized in that: The invention comprises a vibration assembly (13), wherein the vibration assembly (13) comprises a support block (14), a cylinder I (15), a fixing seat (16), a vibration plate (17), a vibration block (18), a vibration motor (19) and a cylinder II (20), wherein the support block (14) is fixedly connected to the outer wall of the ventilation duct (3), the support block (14) is arranged on the upper part of the ventilation duct (3), the cylinder I (15) is fixedly connected to the bottom surface of the support block (14), the cylinder I (15) is arranged outside the ventilation duct (3), and the piston rod of the cylinder I (15) The fixing seat (16) is fixedly connected to the piston rod of the cylinder I (15), the cylinder II (20) is fixedly connected to the fixing seat (16), the piston rod of the cylinder II (20) is arranged toward the ventilation duct (3), the vibration plate (17) is fixedly connected to the piston rod of the cylinder II (20), the vibration motor (19) is fixedly connected to the rear side of the vibration plate (17), the vibration block (18) is fixedly connected to the front side of the vibration plate (17) away from the vibration motor (19), and the vibration block (18) is connected to the outer wall of the ventilation duct (3).

7. The building ventilation duct with a noise reduction structure according to claim 6, characterized in that: There are two cylinders II (20), and the vibration motor (19) is arranged between the two cylinders II (20).

8. The building ventilation duct with a noise reduction structure according to claim 4, characterized in that: The bottom plate (601) is provided with a through hole (604), the inner diameter of the through hole (604) is smaller than the inner diameter of the bottom tube (1102), a blind plate (605) is connected to the bottom surface of the bottom plate (601), the blind plate (605) closes the through hole (604), the blind plate (605) is fixedly connected to the bottom plate (601) by bolts, and a threaded blind hole for bolt connection is opened on the bottom surface of the bottom plate (601).

9. The building ventilation duct with a noise reduction structure according to claim 8, characterized in that: Two support shafts (8) are fixedly connected to the outer wall of the ventilation duct (3). The two support shafts (8) are both arranged at the lower part of the ventilation duct (3). The two support shafts (8) are symmetrical. Connecting rods (9) are rotatably connected to the support shafts (8). The bottom ends of the two connecting rods (9) away from the support shafts (8) are fixedly connected to the collection box (7). The collection box (7) is a box body with an open top surface. The collection box (7) is arranged below the bottom cover (6). The top surface of the collection box (7) is open toward the bottom cover (6). The inner diameter of the collection box (7) is larger than the inner diameter of the ventilation duct (3).

Images