A Roots blower with a flow guide device

Abstract

The present invention discloses a Roots blower with a guide device, comprising a casing, the casing is provided with an air inlet and an exhaust port, the air inlet is provided with an air inlet guide cone, an air inlet flow channel is formed between the air inlet guide cone and the inner wall of the air inlet, the exhaust port is provided with an air outlet guide cone, an air outlet flow channel is formed between the air outlet guide cone and the inner wall of the exhaust port, an exhaust cavity with openings at both ends is provided inside the air outlet guide cone, an exhaust hole connected to the exhaust cavity is provided on the casing, the air inlet guide cone and the exhaust guide cone have concave arc surfaces on the side facing the impeller, and a limit protection valve is provided on the side facing the impeller of the air outlet guide cone. By providing the guide cone, a longer flow channel can effectively delay the reflux process of high-pressure gas, and even if the gas enters the volume formed by the impeller and the casing along the flow channels on both sides of the two guide cones, the generation of gas turbulence can be effectively avoided, thereby solving the problem of high noise of the current blower.

Description

Technical Field

[0001] The invention relates to the technical field of Roots blowers, in particular to a Roots blower with a flow guide device. Background Art

[0002] Roots blower is a positive displacement blower. Its principle is to use two blade-shaped rotors to make relative motion in the cylinder to compress and transport gas. This blower has a simple structure and is easy to manufacture. It is widely used in aquaculture oxygenation, sewage treatment aeration, pneumatic transportation, and is more suitable for gas transportation and pressurization systems in low-pressure occasions. It can also be used as a vacuum pump, etc.

[0003] During the air intake and exhaust process of the fan, the flow velocity at the air inlet and outlet is high, which is prone to turbulence. Turbulence not only causes energy loss but also produces air flow pulsation, thereby increasing the fan noise and affecting the fan performance. At present, in order to solve the turbulence problem of the fan inlet and outlet, special-shaped air outlets are usually provided on the inlet and outlet flanges to reduce the backflow impact noise. The processing of special-shaped air outlets is difficult and the noise reduction effect is not ideal. Summary of the invention

[0004] The present invention is aimed at the above-mentioned deficiencies in the prior art and provides a Roots blower with a guide device. By arranging a guide cone and a casing to form a transition curved surface structure, a longer flow channel can effectively delay the backflow process of the high-pressure gas, thereby reducing the backflow impact intensity and reducing the airflow impact noise; in addition, the guide cone structure can guide the gas to be orderly diverted at the inlet and exhaust ports, that is, in addition, the guide cone structure can guide the gas to be orderly diverted at the inlet and exhaust ports. In the intake stage, the gas enters the rotor intake cavity on both sides along the inlet flow channel, so that the gas is orderly diverted. In the exhaust stage, the gas is discharged from the two rotors along the outlet flow channels respectively, which can effectively avoid the generation of gas turbulence, thereby reducing the fan noise and solving the problem of high fan noise at present.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A Roots blower with a guide device comprises a casing, wherein the casing is provided with an air inlet and an exhaust port, an air inlet guide cone is arranged in the air inlet, an air inlet flow passage is formed between the air inlet guide cone and the inner wall of the air inlet, an air outlet guide cone is arranged in the exhaust port, an air outlet flow passage is formed between the air outlet guide cone and the inner wall of the exhaust port, an exhaust cavity with openings at both ends is arranged inside the air outlet guide cone, an exhaust hole connected with the exhaust cavity is arranged in the casing, the air inlet guide cone and the exhaust guide cone have concave arc surfaces on the side facing the impeller, and a limit protection valve is arranged on the side facing the impeller of the air outlet guide cone.

[0007] Preferably, the inner walls of the air inlet and the air outlet are both smooth convex curved surface structures, and both sides of the air inlet guide cone and the air outlet guide cone are smooth concave curved surface structures.

[0008] Preferably, a filling cavity is provided inside the air intake guide cone, a sound-absorbing material is provided inside the filling cavity, and a sound-absorbing hole communicating with the filling cavity is provided at the bottom of the air intake guide cone.

[0009] Preferably, the sound-absorbing material is polyester sound-absorbing cotton.

[0010] Preferably, the limit protection valve includes a valve bonnet, a spring, a displacement probe rod, and a valve body. A valve bonnet is provided at the end of the valve body. A first air outlet is provided at one end of the valve body. A pressure hole connected to the first air outlet is provided at the other end of the valve body. The diameter of the pressure hole is larger than the diameter of the first air outlet. A second air outlet connected to the bottom of the pressure hole is provided on the side wall of the valve body. The second air outlet is located in the exhaust chamber. The displacement probe rod includes a probe and a pressure rod. The probe is clearance-matched with the first air outlet. One end of the probe extends to the outside of the valve body, and the other end of the probe is connected to the pressure rod. The pressure rod is matched with the pressure hole. A spring is provided between the pressure rod and the valve bonnet. The pressure rod is pressed by the spring to block the first air outlet.

[0011] Preferably, the valve cap is threadedly connected to the valve body.

[0012] Preferably, a pressing groove is provided at one end of the pressing rod away from the probe, and one end of the spring is arranged in the pressing groove.

[0013] Preferably, one end of the pressure rod extends out of the pressure hole, a tooth groove is provided on the side wall of the pressure rod, and an elastic sheet is connected to the end of the valve body, and the elastic sheet cooperates with the tooth groove.

[0014] Preferably, the valve body is threadedly connected to the air outlet guide cone.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The present invention forms a transitional curved surface structure by arranging a guide cone and a casing. A longer flow channel can effectively delay the reflux process of high-pressure gas, thereby reducing the reflux impact intensity and reducing the airflow impact noise; in addition, the guide cone structure can guide the gas to be orderly diverted at the inlet and outlet, even if the gas enters the volume formed by the impeller and the casing along the flow channels on both sides of the two guide cones, it can effectively avoid the generation of gas turbulence, thereby reducing the fan noise, solving the current problem of high fan noise, and having better and more stable cooling effect than the currently used flange special-shaped port; the inlet guide cone has a simple structure and is easy to process.

[0017] 2. The present invention arranges a sound-absorbing material in the air intake guide cone, improves the sound absorption effect through the sound-absorbing holes, effectively absorbs the noise radiated from the exhaust port side, and thus further reduces the fan noise.

[0018] 3. The present invention is provided with a limit protection valve. When the impeller expands, the limit protection valve can be opened before the impeller and the inner wall of the casing wear each other, thereby excluding the air pressure inside the casing. When the internal air pressure and temperature of the machine are reduced, the expansion deformation of the impeller will be reduced, thereby reducing or avoiding the wear between the impeller and the casing and increasing the life of the fan.

[0019] 4. The valve body and the valve cap, as well as the valve body and the casing of the present invention are both connected by threads, which are convenient for disassembly and maintenance, and can carry out targeted replacement of damaged parts of the limit protection valve, thereby saving costs.

[0020] 5. The present invention prevents the pressure rod from resetting by arranging the spring sheet to cooperate with the tooth groove of the side wall of the pressure rod, maintains a continuous exhaust state, and avoids excessive air pressure inside the casing during a fault. After the inspection is completed, the pressure rod is manually reset, which is simple to operate and increases the safety of the fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2 is a cross-sectional view of the present invention;

[0023] Figure 3 It is a schematic diagram of the structure of the air intake guide cone;

[0024] Figure 4 It is a structural schematic diagram of the limit protection valve;

[0025] Figure 5 It is the structural schematic diagram of the displacement probe;

[0026] Figure 6 Schematic diagram of the structure of the valve body.

[0027] In the figure: 1- housing; 101- exhaust hole; 2- air inlet guide cone; 201- filling cavity; 202- sound-absorbing material; 203- sound-absorbing hole; 3- air outlet guide cone; 301- exhaust cavity; 4- limit protection valve; 401- valve cap; 402- spring; 403- spring piece; 404- displacement probe rod; 405- valve body; 406- probe; 407- pressure rod; 408- tooth groove; 409- pressure groove; 410- first air outlet; 411- second air outlet; 412- pressure hole. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] like Figure 1-2 As shown, a Roots blower with a guide device comprises a casing 1, an air inlet and an exhaust port are provided on the casing 1, an air inlet guide cone 2 is provided in the air inlet, an inlet flow passage is formed between the air inlet guide cone 2 and the inner wall of the air inlet, an air outlet guide cone 3 is provided in the exhaust port, an outlet flow passage is formed between the air outlet guide cone 3 and the inner wall of the exhaust port, an exhaust cavity 301 with openings at both ends is provided inside the air outlet guide cone 3, an exhaust hole 101 connected with the exhaust cavity 301 is provided on the casing 1, the air inlet guide cone 2 and the exhaust guide cone have concave arc surfaces on the side facing the impeller, a limit protection valve 4 is provided on the side facing the impeller, which can exhaust and cool down the impeller when the blower is overloaded or the temperature exceeds the safe operating temperature, causing the impeller to expand thermally, thereby effectively avoiding the impeller from colliding with the inner wall of the casing 1.

[0030] Among them, the air inlet guide cone 2 and the air outlet guide cone 3 have the same shape and are both diamond-shaped structures. The two side walls adjacent to the inner wall of the casing 1 are longer, forming an air duct between the inner wall of the casing 1, and the two side walls facing the impeller are relatively short, with a gap between the impeller, and the four surfaces are all smooth transition concave curved surface structures.

[0031] The inner walls of the air inlet and the air outlet are set to a smooth convex surface structure to avoid the angular structure increasing wind resistance and reducing noise. The two sides of the air inlet guide cone 2 and the air outlet guide cone 3 are smooth concave surface structures.

[0032] like Figure 2-3 As shown, a filling cavity 201 is provided inside the air intake guide cone 2 , and a sound absorbing material 202 is provided inside the filling cavity 201 . The sound absorbing material 202 is made of polyester sound absorbing cotton. A sound absorbing hole 203 connected to the filling cavity 201 is provided at the bottom of the air intake guide cone 2 .

[0033] The inlet guide cone 2 is located in the middle of the inlet port, and the outlet guide cone 3 is located in the middle of the exhaust port. The mating surfaces of the two guide cones and the rotor are concave surfaces and have clearance fit, thereby guiding the fluid to be diverted in an orderly manner. In the intake stage, the gas enters the rotor intake cavity on both sides along the intake flow channel, so that the gas is diverted in an orderly manner. In the exhaust stage, the gas is discharged from the two rotors along the outlet flow channels respectively, and the gas is diverted and exhausted in an orderly manner under the action of the outlet guide cone 3, which can effectively avoid the generation of turbulence.

[0034] Both the inlet flow channel and the exhaust flow channel can adopt a volume gradient type. The flow channel length and the volume gradient range can be set according to the flow rate, boost and other parameters of different fans, which can effectively delay the reflux process of the high-pressure gas at the exhaust port, thereby significantly reducing the reflux impact intensity and reducing the airflow impact noise. The inlet guide cone structure can reduce the impact of the high-pressure reflux gas at the exhaust port, and effectively absorb the noise radiated from the exhaust port side through the sound-absorbing material 202.

[0035] like Figure 4-6 As shown, the limit protection valve 4 includes a valve cap 401, a spring 402, a displacement probe rod 404, and a valve body 405. The valve cap 401 is provided at the end of the valve body 405, and one end of the valve body 405 is provided with a first air outlet 410, and the other end of the valve body 405 is provided with a pressure hole 412 connected to the first air outlet 410. The diameter of the pressure hole 412 is larger than the diameter of the first air outlet 410. The side wall of the valve body 405 is provided with a second air outlet 411 connected to the bottom of the pressure hole 412. The second air outlet 411 is located in the exhaust chamber 301, and the displacement probe 404 includes a probe 406 and a pressure rod 407. The probe 406 is in clearance with the first air outlet 410, one end of the probe 406 extends to the outside of the valve body 405, and the other end of the probe 406 is connected to the pressure rod 407, and the pressure rod 407 is in coordination with the pressure hole 412. A spring 402 is provided between the pressure rod 407 and the valve cap 401, and the pressure rod 407 blocks the first air outlet 410 by being pressed by the spring 402.

[0036] In order to facilitate maintenance, the valve cap 401 and the valve body 405 are threadedly connected.

[0037] A pressing groove 409 is formed at one end of the pressing rod 407 away from the probe 406 , and one end of the spring 402 is disposed in the pressing groove 409 .

[0038] In order to improve the fluency of exhaust, one end of the pressure rod 407 extends out of the pressure hole 412, and a tooth groove 408 is provided on the side wall of the pressure rod 407. The end of the valve body 405 is connected to a spring piece 403. The spring piece 403 is a bent structure, one end of which is bolted to the valve body 405 and the other end is inclined to cooperate with the tooth groove 408 to form a ratchet pawl structure. When the probe 406 needs to be reset when it is used next time, the valve body 405 is threadedly connected to the air outlet guide cone 3, and a sealing ring is provided at the connection to facilitate the disassembly of the limit protection valve 4 and the reset operation.

[0039] When the impeller expands due to excessive operating temperature, in order to avoid wear between the impeller and the casing 1, the impeller contacts the displacement probe 404 of the limit protection valve 4 before friction occurs with the inside of the casing 1, and the impeller squeezes the probe 406 to push the pressure rod 407 open. At this time, the first air outlet 410 is connected with the second air outlet 411, and the internal air pressure of the casing 1 flows from the first air outlet 410 through the second air outlet 411 into the exhaust chamber 301, and then is discharged from the exhaust chamber 301 through the exhaust hole 101. The spring 403 locks the pressure rod 407 to prevent it from returning to its original position, and keeps the exhaust state all the time, achieving the effect of rapid pressure reduction and temperature reduction, thereby ensuring the safe operation of the Roots blower.

[0040] The structure of the limit protection valve 4 can be recycled and reused, reducing material costs. After the probe 406 of the limit protection valve 4 is subjected to the thrust of the impeller, exhaust pressure relief and temperature reduction are performed. After the staff inspects and repairs the fan unit, they only need to remove the valve cap 401 of the limit protection valve 4 and manually move the spring 403 to make the limit probe rod fall back for reuse.

[0041] In the traditional form, the inlet and outlet of the casing 1 are respectively provided with rectangular air ports for the blower to inlet and exhaust. The structural feature of this structure is that at the moment when the elementary volume is opened, the high-pressure gas from the exhaust chamber quickly flows back, causing the gas in the elementary volume to suddenly rise, and the airflow impact noise generated thereby is relatively large. In addition, since the Roots blower inhales and exhausts air through two rotors rotating in opposite directions, gas turbulence will be generated at the inlet and outlet of the blower, thereby increasing the noise of the blower. The present application forms a transitional curved surface structure by setting a guide cone and the casing 1. The longer flow channel can effectively delay the reflux process of the high-pressure gas, thereby reducing the reflux impact intensity and reducing the airflow impact noise; in addition, the guide cone structure can guide the gas to be orderly diverted at the inlet and outlet. Even if the gas enters the volume formed by the impeller and the casing 1 along the flow channels on both sides of the two guide cones, it can effectively avoid the generation of gas turbulence, thereby reducing the fan noise.

[0042] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A Roots blower with a flow guide device, comprising a casing, wherein the casing is provided with an air inlet and an air outlet, wherein: An air inlet guide cone is provided in the air inlet, an air inlet flow passage is formed between the air inlet guide cone and the inner wall of the air inlet, an air outlet guide cone is provided in the air outlet, an air outlet flow passage is formed between the air outlet guide cone and the inner wall of the air outlet, an air outlet cavity with openings at both ends is provided inside the air outlet guide cone, an air outlet hole connected with the air outlet cavity is provided on the casing, the side of the air inlet guide cone and the air outlet guide cone facing the impeller is an inwardly concave arc surface, and a limit protection valve is provided on the side of the air outlet guide cone facing the impeller; A filling cavity is provided inside the air intake guide cone, a sound-absorbing material is provided inside the filling cavity, and a sound-absorbing hole communicating with the filling cavity is provided at the bottom of the air intake guide cone; the sound-absorbing material is made of polyester sound-absorbing cotton; The limit protection valve includes a valve bonnet, a spring, a displacement probe rod, and a valve body. A valve bonnet is provided at the end of the valve body, a first air outlet is provided at one end of the valve body, a pressure hole connected to the first air outlet is provided at the other end of the valve body, the diameter of the pressure hole is larger than the diameter of the first air outlet, a second air outlet connected to the bottom of the pressure hole is provided on the side wall of the valve body, and the second air outlet is located in the exhaust chamber. The displacement probe rod includes a probe and a pressure rod. The probe is clearance-matched with the first air outlet, one end of the probe extends to the outside of the valve body, and the other end of the probe is connected to the pressure rod, and the pressure rod is matched with the pressure hole. A spring is provided between the pressure rod and the valve bonnet. The pressure rod is compressed by the spring to block the first air outlet, one end of the pressure rod extends to the outside of the pressure hole, and a tooth groove is provided on the side wall of the pressure rod. A spring is connected to the end of the valve body, and the spring plate is matched with the tooth groove.

2. A Roots blower with a flow guide device as claimed in claim 1, characterized in that: The inner walls of the air inlet and the air outlet are both smooth convex curved surface structures, and the two sides of the air inlet guide cone and the air outlet guide cone are smooth concave curved surface structures.

3. A Roots blower with a flow guide device as claimed in claim 1, characterized in that: The valve cap is threadedly connected to the valve body.

4. A Roots blower with a flow guide device as claimed in claim 1, characterized in that: A pressing groove is arranged at one end of the pressing rod away from the probe, and one end of the spring is arranged in the pressing groove.

5. A Roots blower with a flow guide device as claimed in claim 1, characterized in that: The valve body is threadedly connected to the air outlet guide cone.

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