An improved variable diameter duct

Abstract

This utility model relates to the field of duct technology, and in particular to an improved variable diameter duct, comprising a duct body, the duct body including a variable diameter section, the variable diameter section being a conical cylinder open at both ends, with a first straight pipe section and a second straight pipe section fixedly connected to its small diameter end and large diameter end respectively; the length-to-diameter ratio of the variable diameter section is greater than or equal to 1.5, used to make the airflow cross section transition smoothly; a sound-absorbing component is provided on the inner wall of the variable diameter section. This utility model adopts an extended, gradually changing diameter structure design, which makes the airflow cross section transition smoothly, effectively suppressing the separation of the airflow boundary layer and the generation of eddies, and effectively absorbing and dissipating the noise energy generated by airflow disturbance through the provided sound-absorbing structure.

Description

Technical Field

[0001] This utility model relates to the field of duct technology, specifically to an improved variable diameter duct. Background Technology

[0002] In HVAC and fluid transport systems, reducing ducts are crucial connecting components for achieving cross-sectional transitions between different pipe sections. Currently, the traditional reducing ducts commonly used in the industry are mostly simple structures with different diameters at both ends and a tapered tube directly connecting them in the middle. When airflow passes through such traditional reducing ducts, the abrupt change in the flow cross-section causes the airflow to violently impact the pipe wall at the diameter change, leading to boundary layer separation and the generation of numerous eddies. This intense airflow disturbance not only creates significant local resistance, increases energy loss in the entire ventilation system, and reduces system operating efficiency, but is also a major source of airflow noise in the duct system, especially low- and mid-frequency noise.

[0003] In existing technologies, variable-diameter ducts have short variable-diameter ends and a large variable-diameter range. Furthermore, external sound insulation mainly blocks noise from spreading outwards, which is not effective in fundamentally suppressing noise regeneration from the airflow inside the duct or reducing resistance.

[0004] Therefore, an improved variable diameter duct is needed to address the above problems. Utility Model Content

[0005] The purpose of this invention is to provide an improved variable diameter duct to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] An improved variable diameter duct includes a duct body, the duct body including a variable diameter section, the variable diameter section being a conical cylinder open at both ends, with a first straight pipe section and a second straight pipe section fixedly connected to its small diameter end and large diameter end respectively.

[0008] The aspect ratio of the variable diameter section is greater than or equal to 1.5, which is used to make the airflow cross section transition smoothly.

[0009] The inner wall of the variable diameter section is equipped with a sound-absorbing component.

[0010] As a preferred embodiment of this utility model, the sound-absorbing component is a porous sound-absorbing material layer.

[0011] As a preferred embodiment of this utility model, the sound-absorbing component is made of centrifugal glass wool, rock wool, or melamine foam.

[0012] As a preferred embodiment of this utility model, the silencing component is fixed to the inner wall of the variable diameter section by adhesive bonding.

[0013] As a preferred embodiment of this utility model, the variable diameter section, the first straight pipe section, and the second straight pipe section are made of stainless steel plate.

[0014] As a preferred embodiment of this utility model, the thickness of the silencing component is 10mm to 50mm.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] This invention adopts an extended, gradually changing diameter structure design, which allows the airflow cross section to transition smoothly, effectively suppressing the separation of the airflow boundary layer and the generation of eddies. Furthermore, through the set sound-absorbing structure, it effectively absorbs and dissipates the noise energy generated by airflow disturbance. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0018] Figure 2 This is a cross-sectional schematic diagram of the present invention.

[0019] In the diagram: First straight pipe section 1, reducing section 2, second straight pipe section 3, silencer 4. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0021] To facilitate understanding of this utility model, a more comprehensive description of it will be provided below with reference to relevant embodiments. Several embodiments of this utility model are given. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this utility model will be more thorough and complete.

[0022] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] Please see Figure 1-2 This utility model provides a technical solution:

[0025] For an example, please refer to... Figure 1 , 2 An improved variable diameter duct includes a duct body, which includes a variable diameter section 2. The variable diameter section 2 is a conical cylinder with openings at both ends. The small diameter end and the large diameter end are respectively fixedly connected to a first straight pipe section 1 and a second straight pipe section 3. The length-to-diameter ratio of the variable diameter section 2 is greater than or equal to 1.5, which is used to make the airflow cross section transition smoothly. A sound-absorbing component 4 is provided on the inner wall of the variable diameter section 2.

[0026] The main body of the duct is composed of a first straight pipe section 1, a variable diameter section 2, and a second straight pipe section 3 connected in sequence. The variable diameter section 2 is designed as a conical cylinder, and its core feature is that the length-to-diameter ratio is greater than or equal to 1.5. This extended and gradually changing diameter design significantly reduces the cone angle of airflow expansion or contraction, so that the change of the flow cross section is more gradual when the airflow passes through this area, effectively guiding the airflow to transition smoothly and minimizing the eddies and airflow impact phenomena caused by the separation of the airflow boundary layer, thereby reducing airflow resistance and aerodynamic noise from the source.

[0027] In this embodiment, a sound-absorbing component 4 is firmly installed on the inner wall of the variable diameter section 2. The sound-absorbing component 4 is usually made of centrifugal glass wool, rock wool or porous sound-absorbing material. When the sound wave propagates to the surface of the sound-absorbing component 4, part of it will be reflected on its surface. The sound wave will enter the intricate micropores inside the material. The sound wave will be effectively dissipated by friction and adhesion between the sound wave and the fiber or pore wall inside the material, thereby reducing noise.

[0028] Please refer to Figure 1 , 2 The sound-absorbing component 4 is a porous sound-absorbing material layer. The sound-absorbing component 4 is made of centrifugal glass wool, rock wool or melamine foam. The sound-absorbing component 4 is fixed to the inner wall of the variable diameter section 2 by adhesive bonding. The thickness of the sound-absorbing component 4 is 10mm to 50mm.

[0029] Please refer to Figure 1 , 2 The reducing section 2, the first straight pipe section 1, and the second straight pipe section 3 are made of stainless steel plates.

[0030] The silencing component 4 is fixed to the inner wall of the reducing section 2 by means of bonding or other methods. Its thickness is in the range of 10mm to 50mm. The reducing section 2, the first straight pipe section 1, and the second straight pipe section 3 can be made of metal materials such as stainless steel plates to ensure structural strength and durability.

[0031] Working principle: After the airflow enters the variable diameter section 2 from the first straight pipe section 1, the velocity and pressure are smoothly converted in the extended gradual diameter change channel, which effectively suppresses the generation of eddies. At the same time, the noise carried by the airflow is efficiently absorbed by the silencer 4.

[0032] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An improved reducing duct, comprising a duct body, characterized in that: The main body of the duct includes a variable diameter section (2), which is a conical cylinder with openings at both ends. The small diameter end and the large diameter end are respectively fixedly connected to a first straight pipe section (1) and a second straight pipe section (3). The aspect ratio of the variable diameter section (2) is greater than or equal to 1.5, which is used to make the airflow cross section transition smoothly. A sound-absorbing component (4) is provided on the inner wall of the variable diameter section (2).

2. The improved variable diameter duct according to claim 1, characterized in that: The sound-absorbing component (4) is a porous sound-absorbing material layer.

3. The improved variable diameter duct according to claim 2, characterized in that: The sound-absorbing component (4) is made of centrifugal glass wool, rock wool or melamine foam.

4. The improved variable diameter duct according to claim 3, characterized in that: The silencing component (4) is fixed to the inner wall of the variable diameter section (2) by adhesive bonding.

5. The improved reducing duct according to any one of claims 1-4, characterized in that: The variable diameter section (2), the first straight pipe section (1), and the second straight pipe section (3) are made of stainless steel plates.

6. The improved variable diameter duct according to claim 5, characterized in that: The thickness of the silencing component (4) is 10 mm to 50 mm.

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