Air duct storage device

Abstract

The utility model relates to the technical field of mining air ducts, in particular to an air duct storage device which comprises a collection bin, the collection bin comprises two coaxial annular rings, a plurality of limiting rods are connected between the two annular rings, and the limiting rods are parallel to the axial direction of the annular rings. The multiple limiting rods are arranged in the circumferential direction of the annular ring to form a limiting frame surrounding the outer side face of the air duct. Two parallel clamping rods are arranged outside the collecting bin and located on the two opposite sides in the radial direction of the collecting bin respectively, the length directions of the two clamping rods are perpendicular to the axial direction of the collecting bin, the two clamping rods can reciprocate in the first direction and the second direction, the first direction is arranged in the axial direction of the collecting bin, and the second direction is arranged in the axial direction of the collecting bin. The second direction is arranged in the radial direction of the collecting bin and perpendicular to the length direction of the clamping rods. When the two clamping rods get close to each other in the second direction, the outer circumferential faces of the two clamping rods can make direct contact or indirect contact with the outer circumferential face of the air duct so as to clamp the air duct. According to the air duct compressing device, the air duct can be compressed into the collecting bin automatically, and manual operation is not needed.

Description

Technical Field

[0001] This utility model relates to the field of mining ventilation duct technology, specifically to a ventilation duct storage device. Background Technology

[0002] In coal mining operations, the long-pressure, short-extraction ventilation system plays an irreplaceable and crucial role as a core facility for ensuring underground operational safety. This system not only continuously supplies fresh air to the mine but also promptly removes harmful substances such as methane and dust generated at the working face. Simultaneously, it effectively regulates the high-temperature environment underground, providing miners with a safe working environment and ensuring safe mine production.

[0003] In long-pressure short-extraction equipment, the air duct collection chamber is a component for storing and managing the air duct. It typically includes a chamber frame and an anti-detachment control mechanism, which can lock or release the air duct. The air duct itself is a key transmission channel in the ventilation system. Made of flexible materials, it has good flexibility and sealing properties. It is usually a telescopic frame-type air duct, which plays a role in connecting various ventilation nodes during the air delivery and extraction process.

[0004] Currently, long-pressure short-extraction equipment in coal mines is mostly installed on the support at the tail of the tunneling machine, working in conjunction with the machine. However, when the tunneling machine is reversing, the ventilation ducts in the ventilation duct collection chamber cannot automatically adapt to the machine's position change, requiring manual retraction by workers. This not only results in low automation but also exposes workers to safety hazards such as gas leaks and roof collapses, making safety difficult to guarantee. This fails to meet the demands of automation development and is inconsistent with the direction of smart mine development. Utility Model Content

[0005] To address the technical problem that existing ventilation ducts in the ventilation duct collection chamber cannot automatically adapt to changes in the position of the tunneling machine during reversing operations, requiring manual retraction by workers, which not only results in low automation but also exposes workers to safety hazards such as gas leaks and roof collapses, making it difficult to guarantee safety, this utility model provides a ventilation duct storage device.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A duct storage device includes a collection chamber, which is cylindrical in shape and has an internal space for storing the duct. An anti-detachment mechanism for the duct is connected to the collection chamber. The collection chamber includes two coaxially arranged annular rings, with several limiting rods connected between them. The length direction of each limiting rod is parallel to the axial direction of the annular rings, and the limiting rods are arranged circumferentially around the duct to form a limiting frame surrounding the outer side of the duct. Two parallel clamping rods are provided on the outside of the collection chamber, located on opposite sides radially within the chamber. The length direction of each clamping rod is perpendicular to the axial direction of the collection chamber. Both clamping rods can reciprocate along directions one and two. Direction one is along the axial direction of the collection chamber, and direction two is along the radial direction of the collection chamber and perpendicular to the length direction of the clamping rods. When the two clamping rods approach each other along direction two, their outer circumferential surfaces can directly or indirectly contact the outer circumferential surface of the duct to clamp it.

[0008] The above-described structural design includes two coaxial annular rings and several limiting rods, providing a stable storage space for the ventilation duct. The limiting rods support and circumferentially limit the ventilation duct, preventing twisting and deformation during storage. The clamping rods can move in one direction towards the inlet of the collection chamber, reaching the position where the ventilation duct needs to be compressed. They can also reciprocate in another direction to clamp and release the ventilation duct. When clamping the duct, the clamping rods move in one direction towards the anti-detachment end of the collection chamber, compressing and storing the duct. When the clamping rods are released, the duct will not unfold due to the anti-detachment mechanism, facilitating cyclical operations. Therefore, this application eliminates the need for manual ventilation duct storage, effectively improving automation and avoiding safety hazards such as gas leaks and roof collapses during manual operation, ensuring worker safety.

[0009] As a preferred implementation of a ventilation duct storage device, the collection chamber is externally equipped with a telescopic mechanism. This mechanism includes a telescopic rod, the length of which is aligned along direction one. The telescopic end of the rod is connected to a mounting plate, the surface of which is parallel to the axial direction of the collection chamber. Slide rails are connected to both sides of the mounting plate along direction two, with guide directions along direction two. Sliding blocks are slidably connected to both slide rails, and each slider is connected to one end of a clamping rod. Using this structure, the telescopic mechanism can drive the clamping rod to reciprocate along direction one, and with the slide rails aligned along direction two, the clamping rod can follow the sliders and reciprocate along the slide rails.

[0010] As a preferred implementation of a duct storage device, the distance between each clamping rod and the collection chamber in direction two is always equal. By adopting the above structural scheme, ensuring that the distance between the two clamping rods and the collection chamber in direction two is always equal, it is possible to guarantee uniform radial force on the duct during storage, further ensuring the integrity of the duct and the storage effect.

[0011] As a preferred implementation of the duct storage device, a second telescopic mechanism is installed on the mounting plate. The telescopic direction of the second telescopic mechanism is the same as that of the first telescopic mechanism. The second telescopic mechanism includes a second telescopic rod, which is parallel to the first telescopic rod. The telescopic ends of the second telescopic rod are hinged to one end of two connecting rods, and the other end of each connecting rod is hinged to a slider. Using this structural scheme, the cooperation of the second telescopic mechanism, the second telescopic rod, the connecting rods, and the sliders provides a reliable transmission method for the opposing or receding movements of the clamping rods. When the second telescopic rod extends or retracts, it drives the slider to slide on the slide rail through the connecting rod, thereby achieving synchronous movement of the two clamping rods. This makes the movement of the clamping rods more stable and precise, enabling quick and accurate clamping or releasing of the duct, improving the working efficiency and reliability of the duct storage device, while reducing the risk of equipment failure due to unstable mechanical transmission, and ensuring the normal operation of the duct storage device.

[0012] As a preferred implementation of a wind tunnel storage device, the telescopic end of the second telescopic rod is connected to a connecting plate. The connecting plate has hinge seats on both sides in direction two, and each hinge seat is hinged to a connecting rod. This structural design makes the force transmission between the connecting rod and the second telescopic rod more stable and uniform.

[0013] As a preferred implementation of the ventilation duct storage device, both telescopic mechanisms one and two are pneumatic telescopic cylinders. Using the above structural scheme, pneumatic telescopic cylinders offer advantages such as fast response speed, stable output force, simple structure, and convenient maintenance. By using pneumatic telescopic cylinders for telescopic mechanisms one and two, the ventilation duct storage device can quickly and accurately complete the clamping and storage actions of the ventilation duct, improving work efficiency. Simultaneously, the pneumatic system is safer than the hydraulic system, eliminating safety hazards such as fires caused by hydraulic oil leaks, meeting the stringent safety requirements for equipment in underground coal mines. Furthermore, pneumatic telescopic cylinders have better adaptability to the complex environment of underground coal mines, are less affected by environmental factors such as dust and humidity, reducing equipment failure rates, lowering maintenance costs, and extending equipment lifespan.

[0014] As a preferred implementation of a duct storage device, telescopic mechanisms one and two are electrically connected to a pneumatic control device. This connection enables automated control of both telescopic mechanisms. The pneumatic control device can precisely control the telescopic movement of the pneumatic telescopic cylinders according to a preset program or external signals, allowing the duct storage device to automatically perform clamping, storage, and release operations on the duct according to actual working conditions. This further improves the automation and intelligence of the device, reduces manual intervention, and enhances operational efficiency and safety. Simultaneously, the pneumatic control device can also monitor and adjust the pneumatic system in real time, ensuring the pneumatic telescopic cylinders operate at their optimal state and guaranteeing the stable operation of the duct storage device.

[0015] In a preferred embodiment of the duct storage device, each of the two clamping rods has an arc-shaped component connected to its end furthest from the slider. The arc-shaped components are circular arcs, located on opposite sides of the two clamping rods, with their arc surfaces facing each other. The diameter of the circle containing each arc component is equal to the outer diameter of the duct, and the projection of the axis of the circle containing each arc component onto the second direction coincides with the axis of the duct. This structural design increases the contact area between the clamping rods and the duct, resulting in a more uniform distribution of clamping force and preventing damage to the duct's flexible material due to excessive local pressure. Furthermore, the fact that the diameter of the circle containing each arc component is equal to the outer diameter of the duct, and the projection of the axis of the circle containing each arc component onto the second direction, coincides with the axis of the duct, ensures that the arc surface matches the outer surface shape of the duct, allowing for better fit and improved clamping effect. This prevents the duct from sliding or detaching during storage, ensuring the stability and reliability of the duct storage.

[0016] As a preferred implementation of a duct storage device, the annular ring at the inlet of the collection chamber is trumpet-shaped, with its larger end facing outwards from the inlet. This structural design effectively guides the duct, making it easier for it to enter the collection chamber. When the duct is compressed into the collection chamber by the clamping rods, the trumpet-shaped structure automatically straightens and guides the duct, reducing resistance and friction during entry and preventing damage due to collisions or jamming. This also improves the efficiency and success rate of duct storage, making the process more convenient and smooth.

[0017] The beneficial effects of this utility model include:

[0018] 1. The collection compartment of this application includes two coaxial annular rings and several limiting rods, which can provide a stable storage space for the air duct. The limiting rods can support and limit the air duct in the circumferential direction, preventing the air duct from twisting and deforming during storage.

[0019] 2. The clamping rod in this application can move in one direction towards the inlet end of the collection chamber, moving to the position where the air duct needs to be compressed and stored. It can also reciprocate in another direction to clamp and release the air duct. When clamping the air duct, the clamping rod moves in one direction towards the anti-detachment end of the collection chamber, thus compressing and storing the air duct. When the clamping rod is released, the air duct will not unfold due to the anti-detachment mechanism, facilitating cyclical operations. This application eliminates the need for manual air duct storage, effectively improving automation and avoiding safety hazards such as gas leaks and roof collapses that workers face during manual operation, ensuring worker safety. Attached Figure Description

[0020] To more clearly illustrate the technical solution of this utility model, the drawings used in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a three-dimensional structural diagram of a wind duct storage device according to a specific embodiment of the present utility model;

[0022] Figure 2 This is a top view of a partial structure of a wind tunnel storage device according to a specific embodiment of the present utility model;

[0023] Figure 3 This is a side view of a wind duct storage device according to a specific embodiment of the present utility model;

[0024] Figure 4 This is a schematic diagram of the structure of a ventilation duct in the prior art.

[0025] List of components and reference numerals:

[0026] 1. Collection chamber; 11. Annular ring; 12. Limiting rod; 2. Telescopic mechanism one; 21. Telescopic rod one; 3. Mounting plate; 31. Slide rail; 32. Slider; 4. Clamping rod; 5. Telescopic mechanism two; 51. Telescopic rod two; 52. Connecting plate; 53. Hinge seat; 6. Connecting rod; 7. Pneumatic control device; 8. Arc-shaped component; 9. Anti-detachment mechanism for air duct; 101. Connecting plate; 102. Connecting rod; 103. Air duct. Detailed Implementation

[0027] To make the objectives, features, and advantages of this utility model more apparent and understandable, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this utility model, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] Reference Figure 1-2 This embodiment proposes a ventilation duct storage device, including a collection chamber 1, which is cylindrical and arranged horizontally along its axis. The internal space of the collection chamber 1 is used to store a ventilation duct 103. Figure 4 The prior art shown depicts a retractable frame-type air duct. Specifically, the collection chamber 1 includes two coaxially arranged annular rings 11, located at the inlet end and the anti-detachment end of the collection chamber 1, respectively. Figure 1The inner diameter of the annular ring 11 at the left inlet end of the collection chamber 1 is larger than the outer diameter of the air duct 103 to facilitate its entry. The annular ring 11 at the left inlet end of the collection chamber 1 is trumpet-shaped, with its larger end facing outward from the inlet end, guiding the entry of the air duct 103. The inner diameter of the annular ring 11 at the right anti-detachment end is smaller than the outer diameter of the air duct 103 to prevent it from protruding. Several limiting rods 12 are connected between the two annular rings 11. The length direction of the limiting rods 12 is parallel to the axial direction of the annular rings 11, and the limiting rods 12 are arranged along the circumferential direction of the annular rings 11, forming a limiting frame around the outer side of the air duct 103. The internal space of the collection chamber 1 is composed of the two annular rings 11 and several limiting rods 12, and is used to house the air duct 103. (Refer to...) Figure 1 The collection chamber 1 is connected to the air duct anti-detachment mechanism 9. The air duct anti-detachment mechanism 9 is a mature structure in the prior art. The function of the air duct anti-detachment mechanism 9 is to lock the air duct 103 and prevent the air duct 103 from unfolding after shrinking. Its specific structure and working principle are known to those skilled in the art and will not be described in detail here.

[0029] Figure 1 and Figure 2 In the diagram, arrow X indicates direction one, and arrow Y indicates direction two.

[0030] The collection chamber 1 is externally equipped with two parallel clamping rods 4, symmetrically distributed on opposite sides of the collection chamber 1 in the radial direction. The length direction of both clamping rods 4 is perpendicular to the axial direction of the collection chamber 1. Both clamping rods 4 can reciprocate along direction X via a telescopic mechanism 2, which is axially aligned with the collection chamber 1. Both clamping rods 4 can also reciprocate along direction Y via a telescopic mechanism 5, which is radially aligned with the collection chamber 1 and perpendicular to the length direction of the clamping rods 4. The distance between each clamping rod 4 and the collection chamber 1 in direction Y is always equal.

[0031] Telescopic mechanism 2 is located outside the collection chamber 1. Telescopic mechanism 2 includes a telescopic rod 21, the length of which is aligned with direction X, meaning the length of the telescopic rod 21 is parallel to the length of the limiting rod 12. The telescopic end of the telescopic rod 21 is connected to the mounting plate 3 via a connecting plate 101. The mounting plate 3 is rectangular. Figure 1 The middle connecting plate 101 is connected to the right side of the mounting plate 3. The plate surface of the mounting plate 3 is parallel to the axis of the collection chamber 1 and parallel to the second direction Y. The mounting plate 3 is connected to slide rails 31 on both sides in the second direction Y. The guide direction of the two slide rails 31 is set along the second direction Y. Sliding sliders 32 are slidably connected on the two slide rails 31. Each slider 32 is connected to one end of a clamping rod 4.

[0032] The mounting plate 3 is equipped with a telescopic mechanism 2 5, which includes a telescopic rod 2 51. The telescopic rod 2 51 is parallel to the telescopic rod 1 21, that is, the length direction of the telescopic rod 2 51 is set along the first direction X. The telescopic end of the telescopic rod 2 51 is connected to the connecting plate 52. The connecting plate 52 is connected to hinge seats 53 on both sides in the second direction Y. Each hinge seat 53 is hinged to one end of a connecting rod 6, and the other end of each connecting rod 6 is hinged to a slider 32.

[0033] When the two clamping rods 4 approach each other along direction Y via the telescopic mechanism 2 5, the outer circumferential surfaces of the two clamping rods 4 can directly contact the outer circumferential surface of the air duct 103 or indirectly contact it through the arc-shaped part 8, thereby clamping the air duct 103. (Refer to...) Figure 1 Two arc-shaped components 8 are provided, each arc-shaped component 4 connected to the end of the corresponding clamping rod 4 away from the slider 32. The arc-shaped component 8 is circular, and the two arc-shaped components 8 are located on opposite sides of the two clamping rods 4, with their arc surfaces facing each other. The diameter of the circle containing each arc-shaped component 8 is equal to the outer diameter of the air duct 103, and the projection of the axis of the circle containing each arc-shaped component 8 onto the second direction Y coincides with the axis of the air duct 103. Connecting rods 102 are connected to both ends of each arc-shaped component 8 and the corresponding clamping rod 4, with the length direction of the connecting rods 102 along the second direction Y. (Refer to...) Figure 1 The centerline of the collection chamber 1 is not provided with limiting rods 12 on both sides in direction Y. The arc-shaped part 8 is opposite to the gap between the upper and lower two adjacent limiting rods 12 in direction Y, so that the arc-shaped part 8 can contact the outer peripheral surface of the air duct 103.

[0034] Reference Figure 3 Both telescopic mechanism 12 and telescopic mechanism 25 are pneumatic telescopic cylinders. Both telescopic mechanism 12 and telescopic mechanism 25 are electrically connected to pneumatic control device 7. Pneumatic control device 7 can control telescopic mechanism 12 and telescopic mechanism 25 respectively.

[0035] Work process:

[0036] According to the preset program or the received external signal, the pneumatic control device 7 sends an initial command to the telescopic mechanism 2. The telescopic mechanism 2 drives the telescopic rod 21 to extend in the X direction, thereby causing the mounting plate 3 and the slide rail 31, slider 32 and clamping rod 4 connected to it to move in the X direction to approach the inlet end of the collection chamber 1; the telescopic mechanism 5 is in the initial position, the telescopic rod 51 is not moved, and the two clamping rods 4 are in the initial position on the slide rail 31 with a large distance between them to leave space for clamping the air duct 103.

[0037] The pneumatic control device 7 sends a command to the telescopic mechanism 5, causing its telescopic rod 51 to extend along direction X. When the telescopic rod 51 extends, it drives the two connecting rods 6 through the connecting plate 52 and the hinge seat 53. The connecting rods 6 pull the slider 32 to slide on the slide rail 31, causing the two clamping rods 4 to move towards each other along direction Y. As the clamping rods 4 move towards each other, the arc-shaped part 8 at its end gradually approaches the air duct 103 until it clamps the air duct 103. Because the arc-shaped part 8 is adapted to the shape of the outer surface of the air duct 103, and the two clamping rods 4 are symmetrically distributed and the distance between the two clamping rods 4 and the collection chamber 1 in direction Y is always equal, the air duct 103 is clamped evenly and stably, avoiding damage due to excessive local stress.

[0038] After the air duct 103 is clamped, the pneumatic control device 7 controls the telescopic mechanism 2 to retract in direction X. The telescopic rod 21 of the telescopic mechanism 2 drives the mounting plate 3, clamping rod 4, and the clamped air duct 103 to move into the collection chamber 1 (i.e., the anti-detachment end), compressing and storing the air duct 103 into the collection chamber 1. During this process, the trumpet-shaped annular ring 11 at the inlet end of the collection chamber 1 automatically straightens and guides the air duct 103, reducing the resistance and friction of the air duct 103 entering; the limiting rod 12 inside the collection chamber 1 provides support and circumferential limitation for the air duct 103, preventing the air duct 103 from twisting and deforming.

[0039] When the telescopic mechanism 2 retracts to its limit position, that is, the section of the air duct 103 located between the clamping rod 4 and the annular ring 11 at the right anti-detachment end is completely compressed and stored.

[0040] The pneumatic control device 7 controls the telescopic mechanism 2 5 to retract the telescopic rod 2 51 in direction X, which drives the clamping rod 4 to move in opposite directions in direction Y to release the air duct 103. At this time, the air duct anti-detachment mechanism 9 plays a role in ensuring that the compressed part of the air duct 103 remains firmly in the collection chamber 1, preventing the air duct 103 from unfolding.

[0041] Subsequently, the pneumatic control device 7 controls the extension mechanism 2 to extend, causing the clamping rod 4 to move to a position close to the inlet end of the collection chamber 1, waiting for the next instruction to collect the air duct 103, thereby realizing the cyclic operation.

[0042] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A duct storage device, comprising a collection chamber (1), the collection chamber (1) being cylindrical, the internal space of the collection chamber (1) being used to store a duct (103), and a duct anti-detachment mechanism (9) connected to the collection chamber (1), characterized in that, The collection chamber (1) includes two coaxially arranged annular rings (11), and several limiting rods (12) are connected between the two annular rings (11). The length direction of the several limiting rods (12) is parallel to the axial direction of the annular rings (11), and the several limiting rods (12) are arranged along the circumferential direction of the annular rings (11) to form a limiting frame surrounding the outer side of the air duct (103). The outside of the collection chamber (1) is provided with two parallel clamping rods (4). The two clamping rods (4) are located on opposite sides of the radial direction of the collection chamber (1). The length direction of the two clamping rods (4) is perpendicular to the axial direction of the collection chamber (1). The two clamping rods (4) can reciprocate along direction one and direction two. Direction one is set along the axial direction of the collection chamber (1), and direction two is set along the radial direction of the collection chamber (1) and perpendicular to the length direction of the clamping rods (4). When the two clamping rods (4) approach each other along direction two, the outer peripheral surfaces of the two clamping rods (4) can directly or indirectly contact the outer peripheral surface of the air duct (103) to clamp the air duct (103).

2. The ventilation duct storage device according to claim 1, characterized in that, The outside of the collection chamber (1) is provided with a telescopic mechanism (2). The telescopic mechanism (2) includes a telescopic rod (21). The length direction of the telescopic rod (21) is set along direction one. The telescopic end of the telescopic rod (21) is connected to the mounting plate (3). The plate surface of the mounting plate (3) is parallel to the axial direction of the collection chamber (1) and the plate surface of the mounting plate (3) is parallel to direction two. The mounting plate (3) is connected to slide rails (31) on both sides in direction two. The guide direction of the two slide rails (31) is set along direction two. Sliding sliders (32) are slidably connected on the two slide rails (31). Each sliding slider (32) is connected to one end of a clamping rod (4).

3. The air duct storage device according to claim 2, characterized in that, The distance between each clamp (4) and the collection chamber (1) in direction two is always equal.

4. The air duct storage device according to claim 3, characterized in that, The mounting plate (3) is equipped with a telescopic mechanism two (5), which includes a telescopic rod two (51). The telescopic rod two (51) is parallel to the telescopic rod one (21). The telescopic ends of the telescopic rod two (51) are respectively hinged to one end of two connecting rods (6), and the other end of each connecting rod (6) is respectively hinged to a slider (32).

5. A duct storage device according to claim 4, characterized in that, The telescopic end of the telescopic rod (51) is connected to the connecting plate (52). The connecting plate (52) has hinge seats (53) on both sides in direction two. Each hinge seat (53) is hinged to a connecting rod (6).

6. A duct storage device according to claim 4, characterized in that, Both telescopic mechanism one (2) and telescopic mechanism two (5) are pneumatic telescopic cylinders.

7. A duct storage device according to claim 6, characterized in that, Telescopic mechanism one (2) and telescopic mechanism two (5) are electrically connected to the pneumatic control device (7) respectively.

8. A duct storage device according to claim 1, characterized in that, Both clamping rods (4) are connected to an arc-shaped component (8) at the end away from the slider (32). The arc-shaped component (8) is circular arc-shaped. The two arc-shaped components (8) are located on opposite sides of the two clamping rods (4). The arc surfaces of the two arc-shaped components (8) are set opposite each other. The diameter of the circle where each arc-shaped component (8) is located is equal to the outer diameter of the air duct (103). The projection of the axis of the circle where each arc-shaped component (8) is located in direction two coincides with the axis of the air duct (103).

9. A duct storage device according to claim 8, characterized in that, Each arc-shaped component (8) has a connecting rod (102) connecting its two ends to the clamping rod (4), and the length direction of the connecting rod (102) is set along direction two.

10. A duct storage device according to claim 1, characterized in that, The annular ring (11) at the inlet of the collection chamber (1) is trumpet-shaped, with its larger end facing outward from the inlet.

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