CN118423279A - Roots blower casing - Google Patents

Abstract

The invention provides a Roots blower casing, and mainly relates to the field of Roots blowers. The Roots blower casing comprises a casing body, wherein two sides of the casing body are respectively provided with an air inlet and an air outlet, two impellers are arranged in the casing body in an up-down position relationship, extension sheets are arranged on the upper side and the lower side of the air inlet, and an air inlet converging opening is arranged between the two extension sheets; the air outlet of casing one side sets up the cushion chamber, the cushion chamber both sides set up curved perforated plate, the array sets up a plurality of through-holes on the perforated plate, two have the air-out and receive the beam mouth between the perforated plate. The invention has the beneficial effects that: the invention can radically solve the noise problem of the Roots blower.

Description

Roots blower casing

Technical Field

The invention mainly relates to the field of Roots fans, in particular to a Roots fan shell.

Background

Roots blower is widely used in many industries due to the advantages of simple structure, low cost, high efficiency, stable flow and the like.

But is limited by the self structural characteristics and the working principle of the Roots blower, the Roots blower is particularly noisy when operated, so that the application of the Roots blower in more fields is greatly limited. The main source of noise of the Roots blower is also clear, namely when the blades of the impeller pass through the inlet of the shell, the spaces formed between the adjacent blades and the shell catch full gas, and each space is always in a closed state in the process of conveying the gas to the outlet of the blower along with the rotation of the impeller, and the density and the pressure of the gas in the spaces are equal to those of the gas at the inlet of the blower. But at this point the outlet end would be at a pressure 5 to 10kpa above the inlet pressure due to the continuous delivery of gas through the fan. When the impeller rotates and the airtight interval equal to the density and pressure of the gas at the inlet of the fan is fully filled, and the outlet of the fan is suddenly opened, the high-pressure gas at the outlet end can be rapidly filled into the low-pressure gas in the interval. Because the rotating speed of the fan is higher, each interval is opened very rapidly at the outlet, high-pressure gas at the outlet end can generate great shock waves when filling low-pressure gas into the interval, and causes vibration of a fan shell, a pipeline and the like, so that great impact noise is formed, and the impact noise value can reach more than 110 dB under the condition that no noise reduction measures are taken.

Such large noise values cannot be applied without measures, and various noise reduction or isolation devices are usually installed outside the fan body, for example: and installing a muffler on the inlet and outlet pipeline, packaging the whole fan by using a sound absorption material, and the like. Although a lot of measures are taken, the investment of noise reduction measures is far higher than the manufacturing cost of the fan, the noise source is not eliminated at all, so that the noise reduction effect can be achieved, and the noise cannot be thoroughly eradicated.

Disclosure of Invention

In order to solve the defects in the prior art, the invention provides a Roots blower shell which can radically solve the noise problem of the Roots blower.

The invention aims to achieve the aim, and the aim is achieved by the following technical scheme:

The Roots blower casing comprises a casing body, wherein an air inlet and an air outlet are respectively formed in two sides of the casing body, an inner cavity of the casing body is of an 8-shaped structure, two impellers are arranged in the casing body in an up-down position relationship, extension sheets are arranged on the upper side and the lower side of the air inlet, an air inlet converging opening is formed between the two extension sheets, and the extension sheets are consistent with the extending trend of the inner cavity of the casing body; the air outlet one side of casing sets up the cushion chamber, the cushion chamber both sides set up curved perforated plate, the array sets up a plurality of through-holes on the perforated plate, two have the air-out and receive the beam mouth between the perforated plate, the perforated plate is unanimous with the inner chamber extending trend of casing.

The end point of the extension piece, which is positioned at one end of the air inlet converging port, is a compression starting point, the connecting point of the porous plate and the inner cavity of the shell is a sealing stop point, when one end of the impeller is positioned at the compression starting point, the other end of the impeller is positioned at the sealing stop point, the sealing stop point is a sealing section from the compression starting point to the sealing stop point according to the rotation direction of the impeller, and the backflow compression section is from the sealing stop point to the compression starting point.

The porous plate is detachably connected with the shell.

The buffer cavity is communicated with the air outlet, and is separated from the air inlet through two impellers.

Compared with the prior art, the invention has the beneficial effects that:

The invention has little change to the Roots blower, only partially reforms and adjusts the inner arc section structure of the casing, can reform and upgrade on the basis of the original design, and can thoroughly eliminate the generation root of the impact noise of the blower with extremely low cost.

The Roots blower reduces the pressure impact of the air outlet, thereby reducing impact noise, improving the rotating speed of the blower, reducing the volume of the blower under the condition of meeting the same air quantity or pressure, reducing the consumption of materials for manufacturing the blower, and reducing the direct cost of manufacturing the blower.

The Roots blower structure reduces noise fundamentally, does not need to excessively install silencing isolation facilities, and can reduce larger engineering investment.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic side view of the perforated plate of the present invention;

FIG. 3 is a schematic diagram of the front view of the perforated plate of the present invention;

fig. 4 is a schematic diagram of a prior art structure of the present invention.

The reference numbers shown in the drawings: 1. a housing; 2. an impeller; 3. an extension piece; 4. an air inlet and a beam converging port; 5. a buffer chamber; 6. a porous plate; 7. an air outlet beam-converging port; 11. an air inlet; 12. an air outlet; 31. a compression starting point; 61. a through hole; 62. sealing the dead points.

Detailed Description

The application will be further described with reference to the accompanying drawings and specific embodiments. It is to be understood that these examples are illustrative of the present application and are not intended to limit the scope of the present application. Further, it will be understood that various changes and modifications may be made by those skilled in the art after reading the teachings of the application, and equivalents thereof fall within the scope of the application as defined by the claims.

As shown in fig. 1-3, the Roots blower casing of the present invention comprises a casing 1, wherein two sides of the casing 1 are respectively provided with an air inlet 11 and an air outlet 12, an inner cavity of the casing 1 is in an 8-shaped structure, and two impellers 2 are arranged in the casing 1 in an up-down position relationship. The upper and lower parts of the housing 1 are circular, so that the impeller 2 installed therein can perform stable rotation to complete air supply.

Extension pieces 3 are arranged on the upper side and the lower side of the air inlet 11, an air inlet converging port 4 is arranged between the two extension pieces 3, and the extension trend of the extension pieces 3 is consistent with that of the inner cavity of the shell 1. The upper inner arc and the lower inner arc of the Roots blower shell are extended towards the blower inlet through the extension piece 3, the width of the air inlet 11 at the inner arc of the shell is narrowed, and the length of the inner arc matched with the impeller is increased. The air outlet 12 side of casing 1 sets up cushion chamber 5, cushion chamber 5 both sides set up curved perforated plate 6, perforated plate 6 is unanimous with the inner chamber extending tendency of casing 1. An air outlet beam-converging port 7 is arranged between the two porous plates 6, the upper inner arc and the lower inner arc of the Roots blower housing are extended to the blower outlet by the porous plates 6, the width of an air outlet 12 at the inner arc of the housing is narrowed, and the length of the inner arc matched with the impeller is increased. Specifically, the perforated plate 6 is detachably connected with the shell 1, so that the perforated plate 6 with different apertures or different hole numbers suitable for various working conditions of the fan can be replaced at any time.

Specifically, the buffer cavity 5 is communicated with the air outlet 12, and the buffer cavity 5 is separated from the air inlet 11 by the two impellers 2.

The perforated plate 6 is provided with a plurality of through holes 61 in an array manner, and the buffer cavity 5 is connected with the inner cavity of the shell 1 through the through holes 61.

The end point of the extension piece 3 at one end of the air inlet converging port 4 is a compression starting point 31, the connection point of the porous plate 6 and the inner cavity of the shell 1 is a sealing stop point 62, when one end of the impeller 2 is positioned at the compression starting point 31, the other end of the impeller 2 is positioned at the sealing stop point 62, a sealing section is formed from the compression starting point 31 to the sealing stop point 62 according to the rotation direction of the impeller 2, and a backflow compression section is formed from the sealing stop point 62 to the compression starting point 31.

In the running process of the Roots blower, when the blades of the impeller 2 pass through the air inlet converging port 4, the interval formed between the adjacent blades and the shell captures full gas. In the process of forming a closed chamber and sending gas to the air outlet 12 of the fan along with the rotation of the impeller 2, after the top points of the front impeller blades of the closed chamber exceed the sealing dead points 62 of the separation chamber and enter the arc section of the porous plate 6, a part of through holes 61 on the porous plate 6 are communicated with the closed chamber, high-pressure gas at the air outlet 12 side of the fan starts to be injected into the closed chamber from a part of through holes 61 of the porous plate 6, low-pressure gas of the closed chamber is compressed, and the density and the pressure start to be increased. The number of holes of the perforated plate 6 communicated with the closed chamber by the continuous rotation of the impeller is gradually increased, and the flow rate of the backflow gas is gradually increased until the pressure of the closed chamber is equal to or similar to the pressure of the air outlet 12 of the fan, and the top points of the blades of the front impeller of the closed chamber scratch the perforated plate to be close to the side edge of the air outlet 12 of the fan, so that the whole chamber is completely opened with the air outlet 12 of the fan, and the gas compressed to be equal to or similar to the pressure of the air outlet 12 of the fan is discharged into an outlet pipeline of the fan.

Each closed chamber is sequentially scratched by the arc sections of the perforated plate 6 of the inner shell of the fan, namely, the process that high-pressure gas at the side of the air outlet 12 of the fan is gradually injected into the separation cavity to compress the gas of the closed chamber, when the communication is started, the gas density of the chamber is minimum, the pressure difference between the gas and the backflow chamber of the perforated plate is maximum, but the flow rate of the backflow gas is also less because the number of the communicated holes is small. After being split by the orifice plate, the density and pressure of the gas in the separation chamber can only be increased without noise due to loss of impact energy, and the number of the through holes 61 communicated with the closed chamber can be gradually increased along with continuous rotation of the impeller 2, but the density and pressure of the gas in the separation chamber are increased, the pressure difference between the backflow gas and the separation chamber is reduced, and the backflow gas also loses the impact energy, so that the flow of the backflow gas can not cause too great impact in the process of gradually increasing until the pressure of the closed chamber is equal to or similar to the pressure of the outlet of the fan, and the pressure difference is almost zero after the separation chamber and the outlet of the fan are completely opened, and no impact can be generated.

By adopting the technology, the impact noise of the Roots blower can be basically eliminated. The Roots blower without impact noise is environment friendly from the original high noise manufacturing source. The method has the advantages of wide application field and rapid increase of the application amount, and can also play a great role in promoting social production.

Because the noise source of the traditional Roots blower is the pressure difference of the air outlet, the Roots blower without impact noise manufactured by the technology can properly improve the outlet pressure of the blower without worrying about impact noise caused by the pressure difference, and the serial number of the Roots blower in high-pressure environment is reduced, thereby reducing the occupied space of the blower and the investment cost.

The Roots blower without impact noise can increase the rotating speed of the blower again without taking the noise into consideration, so that the volume of the blower can be reduced under the condition of meeting the same air quantity or pressure, the consumption of materials for manufacturing the blower is reduced, and the direct cost for manufacturing the blower is reduced.

Furthermore, the Roots blower housing is also suitable for three-blade blowers or multi-blade blowers, and the position and the size of the porous plate 6 are only required to be adjusted according to the number of blades.

Claims (4)

1. The utility model provides a roots blower casing, includes casing (1), casing (1) both sides have air intake (11) and air outlet (12) respectively, casing (1) inner chamber is "8" style of calligraphy structure, be upper and lower positional relationship in casing (1) and set up two impeller (2), its characterized in that: extension sheets (3) are arranged on the upper side and the lower side of the air inlet (11), an air inlet converging opening (4) is arranged between the two extension sheets (3), and the extension trend of the extension sheets (3) is consistent with that of the inner cavity of the shell (1); the utility model discloses a buffer chamber (5) is set up in air outlet (12) one side of casing (1), buffer chamber (5) both sides set up curved perforated plate (6), the array sets up a plurality of through-holes (61) on perforated plate (6), two have air-out and receive beam opening (7) between perforated plate (6), perforated plate (6) are unanimous with the inner chamber extending trend of casing (1).

2. A Roots blower housing according to claim 1, wherein: the end point of the extension piece (3) at one end of the air inlet converging port (4) is a compression starting point (31), the connecting point of the porous plate (6) and the inner cavity of the shell (1) is a sealing stop point (62), when one end of the impeller (2) is located at the compression starting point (31), the other end of the impeller (2) is located at the sealing stop point (62), the compression starting point (31) is a sealing section from the sealing stop point (62) to the compression starting point (31) is a backflow compression section according to the rotation direction of the impeller (2).

3. A Roots blower housing according to claim 1, wherein: the porous plate (6) is detachably connected with the shell (1).

4. A Roots blower housing according to claim 1, wherein: the buffer cavity (5) is communicated with the air outlet (12), and the buffer cavity (5) is separated from the air inlet (11) through the two impellers (2).