Breathing machine

Abstract

The invention discloses a breathing machine which comprises an air inlet, a first air inlet channel and a second air inlet channel. The first air inlet channel is communicated with the air inlet; the second air inlet channel comprises a first part and a second part which are arranged in an L shape, the first air inlet channel and the first part are distributed in an up-down stacked mode, and the end, away from the air inlet, of the first air inlet channel communicates with the first part; the first air inlet channel and the second air inlet channel are both located on the periphery of the fan bin. The air inlet duct entering the small breathing machine is optimized, the noise reduction effect of the breathing machine is improved, and the experience effect of a curer is better.

Description

TECHNICAL FIELD

[0001] The present application relates to a breathing machine, belonging to the technical field of breathing machines. BACKGROUND

[0002] In modern clinical medicine, breathing machine as an effective means to artificially replace the self-ventilation function, has been widely used in respiratory failure caused by various reasons, anesthesia and respiratory management during major operation, respiratory support therapy and emergency resuscitation, and occupies a very important position in the field of modern medicine. Breathing machine is a very important medical equipment which can prevent and treat respiratory failure, reduce complications, save and prolong the life of patients.

[0003] Most of the existing breathing machines are driven by a fan to drive the flow of gas to assist the patient in breathing. However, the existing breathing machines generate a lot of vibration and noise during use, which affects the use of patients, and this situation is particularly evident on small breathing machines. SUMMARY

[0004] In order to reduce the noise generated by the airflow inside the breathing machine and improve the user experience of the patient, the present application provides a breathing machine, and the specific technical solutions are as follows.

[0005] A breathing machine, characterized in that it comprises an air inlet, a first air inlet channel and a second air inlet channel.

[0006] The first air inlet channel is in communication with the air inlet; the second air inlet channel comprises a first part and a second part arranged in an L shape, the first air inlet channel and the first part are arranged in an upper and lower stacking manner, and one end of the first air inlet channel away from the air inlet is in communication with the first part; the first air inlet channel and the second air inlet channel are located on the periphery of the fan compartment.

[0007] By adopting the above technical solutions, the first air inlet channel and the first part of the second air inlet channel are arranged in an upper and lower stacking manner, which prolongs the air inlet channel; the second air inlet channel is arranged in an L shape, which further prolongs the air inlet channel, so that a better noise reduction effect can be achieved; the first air inlet channel and the second air inlet channel are located on the periphery of the fan compartment, which is beneficial to fully utilize the internal space of the breathing machine without increasing the size of the small breathing machine.

[0008] Further, it further comprises a transition chamber and a fan compartment chamber, the transition chamber is located above the second air inlet channel, the transition chamber and the second air inlet channel are in communication through a vertically arranged air resistance pipe; the fan compartment chamber is located in the fan compartment, and the fan compartment chamber is in communication with the transition chamber.

[0009] Further, the ventilator further comprises a ventilator upper cover, a ventilator base and a ventilator damping and silencing part, the ventilator damping and silencing part is made of flexible material, the ventilator damping and silencing part is clamped between the ventilator upper cover and the ventilator base, and the ventilator is enclosed by the ventilator upper cover and the ventilator base. The ventilator damping and silencing part provides flexible support for the ventilator body, which helps to reduce damping and noise reduction. Preferably, the flexible material is at least one of silicone, TPE, TPR, polyurethane, neoprene, polypropylene, fluororubber, polysulfide rubber or nitrile rubber.

[0010] Further, the ventilator damping and silencing part comprises an airway separation wall, the airway separation wall is located outside the ventilator, the first air inlet channel is located between the airway separation wall and the ventilator upper cover, and the first part of the second air inlet channel is located between the airway separation wall and the ventilator base. That is, the flexible airway separation wall becomes a separation wall of the first air inlet channel and the first part of the second air inlet channel, which not only simplifies the assembly process, but also helps to reduce noise.

[0011] Further, the ventilator damping and silencing part comprises a sound attenuation chamber wall, the sound attenuation chamber wall is located outside the ventilator, the sound attenuation chamber wall and the ventilator upper cover form a sound attenuation chamber, the sound attenuation chamber wall has a plurality of through holes, the second part of the second air inlet channel and the sound attenuation chamber are communicated through the through holes, and the second part of the second air inlet channel is located between the sound attenuation chamber wall and the ventilator base. Preferably, the sound attenuation chamber comprises adjacent first and second sound attenuation chambers, the first and second sound attenuation chambers are communicated with the second part of the second air inlet channel through the through holes, and the volume of the first sound attenuation chamber is smaller than that of the second sound attenuation chamber.

[0012] Further, the ventilator base is provided with a flow guide strip, the flow guide strip is located in the first part of the second air inlet channel, and the flow guide strip extends from the side wall of the ventilator base to the second part of the second air inlet channel. Preferably, the flow guide strip is provided with three parallel flow guide strips, and the middle flow guide strip is higher than the two side flow guide strips.

[0013] Further, the second part of the second air inlet channel is further provided with a vertically extending flow guide column, the flow guide column is located directly below the flow resistance pipe; the flow guide column comprises a baffle, a first flow guide piece and a second flow guide piece; the first part and the second part are connected to be called a connection end, the first flow guide piece is fixed to one side of the baffle facing the connection end, and the second flow guide piece is fixed to the other side of the baffle away from the connection end. Preferably, a plurality of first flow guide pieces are arranged in parallel, and a plurality of second flow guide pieces are arranged radially. Preferably, the number of first flow guide pieces is greater than the number of second flow guide pieces.

[0014] Compared with the prior art, the present application has the following beneficial effects.

[0015] 1. The air inlet duct is lengthened in the small respirator, the noise reduction effect of the respirator is improved, and the experience effect of the patient is better.

[0016] 2. The fan damping and noise reduction part is used to reduce the noise of the fan, and becomes the partition wall of the first part of the first air inlet channel and the second air inlet channel, which simplifies the assembly process in the case of lengthening the air inlet duct.

[0017] 3. The fan damping and noise reduction part and the upper cover of the fan bin are used to form the first noise reduction chamber and the second noise reduction chamber above the second air inlet channel, which reduces the noise and simplifies the assembly process.

[0018] 4. The flow guide strip and the flow guide column are arranged, which obviously reduces the airflow turbulence and is beneficial to reducing the noise. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is an exploded schematic view of the respirator of the present application;

[0020] Figure 2 is a schematic view of the respirator base;

[0021] Figure 3 is Figure 2 an enlarged view of the A area in the respirator;

[0022] Figure 4 is a bottom view of the upper cover of the fan bin;

[0023] Figure 5 is a schematic view of the fan damping and noise reduction part;

[0024] Figure 6 is a longitudinal sectional view of the respirator;

[0025] Figure 7 is Figure 6 a schematic view of air flow in the sectional view state;

[0026] Figure 8 is another longitudinal sectional view of the respirator;

[0027] Figure 9 is a schematic view of air flow in the transverse sectional view state of the respirator;

[0028] Figure 10 is a schematic view of the basic structure of the Helmholtz resonator;

[0029] Figure 11 is a sound pressure cloud chart without two noise reduction chambers (the simulated noise frequency is 1055HZ);

[0030] Figure 12 is the sound pressure cloud chart of two muffler rooms (the simulation noise frequency is 1055HZ);

[0031] Figure 13 is the sound pressure cloud chart of two muffler rooms (the simulation noise frequency is 1922HZ);

[0032] Figure 14 is the sound pressure cloud chart of two muffler rooms (the simulation noise frequency is 1922HZ);

[0033] Figure 15 is the airway cross-section velocity cloud chart when three guide vanes are of the same height;

[0034] Figure 16 is the airway cross-section velocity cloud chart when the middle guide vane is higher;

[0035] Figure 17 is the airway cross-section turbulent kinetic energy cloud chart when three guide vanes are of the same height;

[0036] Figure 18 is the airway cross-section turbulent kinetic energy cloud chart when the middle guide vane is higher;

[0037] Figure 19 is the axial cross-section turbulent kinetic energy cloud chart of the wind resistance pipe without guide vanes;

[0038] Figure 20 is the axial cross-section turbulent kinetic energy cloud chart of the wind resistance pipe with guide vanes.

[0039] In the figure: ventilator upper cover 1, ventilator base 2, air inlet 2.1, guide vane 2.2, humidifier 3, fan damping and noise reduction part 4, ventilation passage 4.1, airway partition wall 4.2, muffler wall 4.3, through hole 4.3.1, wind resistance pipe mounting hole 4.4, fan compartment upper cover 5, fan compartment side wall 5.1, communication hole 5.2, fan body 6, fan compartment 7, fan compartment upper chamber 7.1, fan compartment lower chamber 7.2, first air inlet passage 8, second air inlet passage 9, first part 9.1, second part 9.2, transition chamber 10, fan compartment chamber 11, wind resistance pipe 12, first muffler room 13, second muffler room 14, guide column 15, baffle 15.1, first guide vane 15.2, second guide vane 15.3. DETAILED DESCRIPTION

[0040] The application will be further described in detail below with reference to the accompanying drawings.

[0041] Referring to Figures 1-9 , the ventilator comprises a ventilator upper cover 1, a ventilator base 2, and a humidifier 3, and the ventilator upper cover 1 and the ventilator base 2 are provided with a fan damping and noise reduction part 4, a fan compartment upper cover 5 and a fan body 6;

[0042] The fan vibration-damping and silencer 4 is made of a flexible material and is clamped between the fan compartment cover 1 and the ventilator base 2. The fan compartment 7 is enclosed by the fan compartment cover 1 and the ventilator base 2. The fan body 6 is fixed by the fan vibration-damping and silencer 4 and the fan compartment cover 5. The fan body 6 is accommodated in the fan compartment 7. An upper fan compartment chamber 7.1 is formed between the fan vibration-damping and silencer 4 and the fan compartment cover 1, and a lower fan compartment chamber 7.2 is formed between the fan vibration-damping and silencer 4 and the ventilator base 2. The fan vibration-damping and silencer 4 has a plurality of ventilation channels 4.1, which connect the upper fan compartment chamber 7.1 and the lower fan compartment chamber 7.2. The fan vibration-damping and silencer 4 provides flexible support for the fan body 6, helping to reduce vibration and noise. Preferably, the flexible material is at least one of silicone, TPE, TPR, polyurethane, chloroprene rubber, polypropylene, fluororubber, polysulfide rubber or nitrile rubber.

[0043] The ventilator base 2 is provided with an air inlet 2.1, and the air inlet channel of the ventilator includes a first air inlet channel 8, a second air inlet channel 9, a transition chamber 10 and a fan chamber 11;

[0044] The first air inlet channel 8 is connected to the air inlet 2.1; the second air inlet channel 9 includes a first portion 9.1 and a second portion 9.2 in an L-shaped layout. The first air inlet channel 8 and the first portion 9.1 are arranged in an upper and lower stacked arrangement, and the end of the first air inlet channel 8 away from the air inlet 2.1 is connected to the first portion 9.1. The first air inlet channel 8 and the second air inlet channel 9 are both located outside the fan compartment 7.

[0045] The transition chamber 10 is located above the second air inlet channel 9, and the transition chamber 10 and the second air inlet channel 9 are connected through a vertically arranged wind resistance tube 12; the fan bin chamber 11 is located in the fan bin 7, and the fan bin chamber 11 includes the above-mentioned fan bin upper chamber 7.1 and the fan bin lower chamber 7.2; the fan bin upper cover 5 has a fan bin side wall 5.1, and the fan bin side wall 5.1 is provided with a connecting hole 5.2, and the fan bin upper chamber 7.1 of the fan bin chamber 11 is connected with the transition chamber 10 through the connecting hole 5.2; wherein, the wind resistance tube 12 is a conventional component in the ventilator, and a wind resistance plate (not shown) is usually provided in the wind resistance tube 12.

[0046] The air passage partition wall 4.2 of the fan damping and noise reduction part 4 is located outside the fan bin 7, the first air inlet channel 8 is located between the air passage partition wall 4.2 and the fan bin upper cover 1, and the first part 9.1 of the second air inlet channel 9 is located between the air passage partition wall 4.2 and the respirator base 2. That is, the flexible air passage partition wall 4.2 becomes a partition wall of the first air inlet channel 8 and the first part 9.1 of the second air inlet channel 9, which not only simplifies the assembly process, but also helps to reduce noise. The fan damping and noise reduction part 4 also has a wind resistance pipe mounting hole 4.4 for the wind resistance pipe 12 to penetrate.

[0047] The sound reduction chamber wall 4.3 of the fan damping and noise reduction part 4 is located outside the fan bin 7, the sound reduction chamber wall 4.3 and the fan bin upper cover 5 form a sound reduction chamber, the sound reduction chamber wall 4.3 has a plurality of through holes 4.3.1, the second part 9.2 of the second air inlet channel 9 and the sound reduction chamber are communicated through the through holes 4.3.1, and the second part 9.2 of the second air inlet channel 9 is located between the sound reduction chamber wall 4.3 and the respirator base 2. Preferably, the sound reduction chamber includes adjacent first and second sound reduction chambers 13 and 14, the first and second sound reduction chambers 13 and 14 are communicated with the second part 9.2 of the second air inlet channel 9 through the through holes 4.3.1, the volume of the first sound reduction chamber 13 is smaller than that of the second sound reduction chamber 14, and different frequencies of noise can be reduced. The sound reduction principle of the first and second sound reduction chambers 13 and 14 utilizes the principle of the Helmholtz resonance cavity.

[0048] The basic structure of the Helmholtz resonance cavity is shown in Figure 10 , which is composed of a neck and a main cavity. In this embodiment, the through hole 4.3.1 constitutes the neck, and the first sound reduction chamber 13 (or the second sound reduction chamber 14) constitutes the main cavity. Each Helmholtz resonance cavity has a natural frequency. When the external sound pressure reaches near this frequency, the air column at the neck moves back and forth violently, rubs against the neck wall and converts sound energy into heat energy to dissipate, thereby achieving sound absorption effect.

[0049] For example, the volume of the first sound reduction chamber 13 is set to 19000mm 3 , and the volume of the second sound reduction chamber 14 is set to 5910mm 3 .

[0050] The formula for calculating the natural frequency f of the Helmholtz resonance cavity is:

[0051]

[0052] Where L is the length of the neck of the resonance cavity, A is the cross-sectional area of the neck of the resonance cavity, V is the volume of the main cavity of the resonance cavity, and C is the speed of sound.

[0053] Since the sound attenuation ability of Helmholtz resonator is approximately symmetrical on both sides of the natural frequency, in the embodiment, the natural frequency of the first sound attenuation chamber 13 can be set in the range of 800-1300HZ, and the natural frequency of the second sound attenuation chamber 14 can be set in the range of 1800-2100HZ.

[0054] According to the fan noise spectrum obtained by actual measurement, the noise is larger in the sound pressure at 1000HZ and 2000HZ, so the natural frequency f1 of the first sound attenuation chamber 13 is designed to be 1000HZ, and the natural frequency f2 of the second sound attenuation chamber 14 is designed to be 2000HZ. The simulation calculation result shows that the natural frequency of the first sound attenuation chamber is 1055HZ, and the natural frequency of the second sound attenuation chamber is 1922HZ, which is basically the same as the formula calculation result.

[0055] At the frequencies of 1055HZ and 1922HZ, resonance occurs in the sound attenuation chamber, as shown in Figures 11-14 , 1055HZ corresponds to the first sound attenuation chamber 13, and 1922HZ corresponds to the second sound attenuation chamber 14. On the outlet cross section of the sound field, the sound pressure intensity decreases by 23% and 15%, respectively. Figures 11-14 In the sound pressure diagram, the deeper the blue color, the stronger the sound pressure and the higher the noise; after adding the sound attenuation chamber, the sound pressure in the P region and the Q region of the sound pressure diagram is obviously reduced, indicating that the noise is effectively reduced.

[0056] In a preferred embodiment, as shown in Figure 6 , Figure 8 , the ventilator base 2 is provided with a flow guide strip 2.2, the flow guide strip 2.2 is located in the first part 9.1 of the second air inlet channel 9, and the flow guide strip 2.2 extends from the side wall of the ventilator base 2 to the second part 9.2 of the second air inlet channel 9. Preferably, three flow guide strips 2.2 are arranged in parallel, and the middle flow guide strip 2.2 is higher than the two side flow guide strips 2.2; the purpose is to make the airflow velocity at the outlet of the three flow guide strips 2.2 close, so as to avoid airflow separation caused by excessive velocity difference to generate new noise sources. Figure 15 is the airflow cross-sectional velocity cloud diagram when the three flow guide strips 2.2 are of the same height, Figure 16 is the airflow cross-sectional velocity cloud diagram when the middle flow guide strip 2.2 is higher; from Figure 15 , it can be observed that the airflow velocity on the right side of the equal-height flow guide strip is significantly higher than that on the left side of the inlet channel, and the velocity difference of the four airways on the cross section of the airflow channel using the middle flow guide strip with higher design is very small, as shown in Figure 16 . Figure 17 is the turbulent kinetic energy cloud diagram of the airflow cross section using the equal-height design flow guide strip, Figure 18 is the turbulent kinetic energy cloud diagram of the airflow cross section using the middle flow guide strip with higher design, and it can be observed that the turbulent kinetic energy is significantly reduced.

[0057] In a preferred embodiment, as shown in Figure 2 ,Figure 3 As shown, a vertically extending flow guide column 15 is further arranged in the second portion 9.2 of the second air inlet channel 9, and the flow guide column 15 is located directly below the air resistance pipe 12; the flow guide column 15 comprises a baffle 15.1, a first flow guide fin 15.2 and a second flow guide fin 15.3; the connection end 9.3 is located at the connection between the first portion 9.1 and the second portion 9.2, the first flow guide fin 15.2 is fixed to one side of the baffle 15.1 facing the connection end 9.3, and the second flow guide fin 15.3 is fixed to the other side of the baffle 15.1 away from the connection end 9.3. Preferably, a plurality of first flow guide fins 15.2 are arranged in parallel, and a plurality of second flow guide fins 15.3 are arranged radially. Preferably, the number of first flow guide fins 15.2 is greater than the number of second flow guide fins 15.3.

[0058] The first flow guide fin 15.2 is located on the windward side, and the second flow guide fin 15.3 is located on the leeward side; all of the first flow guide fins 15.2 are perpendicular to the baffle 15.1, and some of the second flow guide fins 15.3 are arranged obliquely relative to the baffle 15.1; the number of first flow guide fins 15.2 is greater than the number of second flow guide fins 15.3. On the one hand, the flow rate entering the air resistance pipe 12 through the first flow guide fin 15.2 is greater, and the turbulent kinetic energy is also greater, so more flow guide fins are needed to regulate and eliminate turbulence; on the other hand, the resistance at the front end is appropriately increased to guide the airflow into the rear end; the flow rate entering the air resistance pipe through the second flow guide fin 15.3 is smaller, and the turbulent kinetic energy is also smaller, and if the number of second flow guide fins 15.3 is excessively increased, not only will the turbulent kinetic energy not be significantly reduced, but the air resistance in the direction of the second flow guide fin 15.3 will be significantly increased, increasing the load of the fan. Before the external air enters the transition chamber 10 through the second portion 9.2 of the second air inlet channel 9, it will pass through the flow guide strip 2.2 and the flow guide column 15 in sequence; the flow guide strip 2.2 can effectively reduce the turbulent noise originally generated by the 180° turn through flow regulation, and the flow guide column 15 can limit the airflow in the direction other than the axial direction of the air resistance pipe 12 by dividing the air inlet cross section of the air resistance pipe 12, thereby reducing the turbulent kinetic energy and reducing the pressure fluctuation of the pressure tapping. Figure 19 The turbulent kinetic energy cloud map of the axial cross section of the air resistance pipe 12 without the flow guide column 15 is as follows, Figure 20 The turbulent kinetic energy cloud map of the axial cross section of the air resistance pipe 12 with the flow guide column 15 is as follows, and it can be seen that the turbulent kinetic energy in the air resistance pipe 12 is significantly reduced after the flow guide column 15 is used.

[0059] As Figure 7 , Figure 9As shown, the air intake sequence of the ventilator of the embodiment is as follows: external air enters the first air inlet channel 8 from the air inlet 2.1, enters the first part 9.1 of the second air inlet channel 9 at the end of the first air inlet channel 8, turns at the first part 9.1 into the second part 9.2, then enters the transition chamber 10 through the wind resistance pipe 12, enters the upper fan compartment 7.1 of the fan compartment chamber 11 through the communication hole 5.2, then enters the lower fan compartment 7.2 through the ventilation channel 4.1, the air in the lower fan compartment 7.2 is pressurized by the fan body 6 and then delivered to the humidifier 3 downstream to increase humidity, and then discharged to the outside of the ventilator. The first air inlet channel 8 and the first part 9.1 of the second air inlet channel 9 are arranged in an up-down stacking manner, which prolongs the air inlet channel; the second air inlet channel 9 is arranged in an L shape, which further prolongs the air inlet channel, so that a better noise reduction effect can be achieved; the first air inlet channel 8 and the second air inlet channel 9 are both located at the periphery of the fan compartment 7, which is conducive to fully utilizing the internal space of the ventilator without increasing the size of the small ventilator.

[0060] The embodiments of the present application are described above in combination with the drawings, and the embodiments and features in the embodiments of the present application can be combined with each other without conflict. The specific embodiments described above are only illustrative, not limiting, and those skilled in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims. These all belong to the protection scope of the present application.

Claims

1. A ventilator, characterized in that: It comprises an air inlet (2.1), a first air inlet channel (8) and a second air inlet channel (9); The first air inlet channel (8) is connected to the air inlet (2.1); the second air inlet channel (9) comprises a first part (9.1) and a second part (9.2) in an L-shaped layout, the first air inlet channel (8) and the first part (9.1) are arranged in an upper and lower overlapping manner, and the end of the first air inlet channel (8) away from the air inlet (2.1) is connected to the first part (9.1); the first air inlet channel (8) and the second air inlet channel (9) are both located on the periphery of the fan compartment (7).

2. A ventilator according to claim 1, characterized in that It also includes a transition chamber (10) and a fan chamber (11), wherein the transition chamber (10) is located above the second air inlet channel (9), and the transition chamber (10) and the second air inlet channel (9) are connected via a vertically arranged wind resistance tube (12); the fan chamber (11) is located in the fan chamber (7), and the fan chamber (11) is connected to the transition chamber (10).

3. A ventilator according to claim 1, characterized in that The invention also includes a fan silo cover (5), a ventilator base (2) and a fan vibration-damping and noise-reducing component (4), wherein the fan vibration-damping and noise-reducing component (4) is made of a flexible material, and the fan vibration-damping and noise-reducing component (4) is clamped between the fan silo cover (5) and the ventilator base (2), and the fan silo (7) is formed by the fan silo cover (5) and the ventilator base (2); preferably, the flexible material is at least one of silicone, TPE, TPR, polyurethane, chloroprene rubber, polypropylene, fluororubber, polysulfide rubber or nitrile rubber.

4. A ventilator according to claim 3, characterized in that The fan vibration-damping and sound-absorbing component (4) comprises an airway partition wall (4.2), the airway partition wall (4.2) is located outside the fan compartment (7), the first air inlet channel (8) is located between the airway partition wall (4.2) and the fan compartment upper cover (5); and the first part (9.1) of the second air inlet channel (9) is located between the airway partition wall (4.2) and the ventilator base (2).

5. A ventilator according to claim 3, characterized in that The fan vibration-damping and sound-absorbing component (4) comprises a sound-absorbing chamber wall (4.3), the sound-absorbing chamber wall (4.3) is located outside the fan chamber (7), the sound-absorbing chamber wall (4.3) and the fan chamber upper cover (5) form a sound-absorbing chamber, the sound-absorbing chamber wall (4.3) has a plurality of through holes (4.3.1), the second part (9.2) of the second air inlet channel (9) and the sound-absorbing chamber are connected through the through holes (4.3.1); the second part (9.2) of the second air inlet channel (9) is located between the sound-absorbing chamber wall (4.3) and the ventilator base (2).

6. A ventilator according to claim 5, characterized in that The muffler chamber comprises a first muffler chamber (13) and a second muffler chamber (14) adjacent to each other. The first muffler chamber (13) and the second muffler chamber (14) are both connected to the second portion (9.2) of the second air inlet channel (9) through the through hole (4.3.1). The volume of the first muffler chamber (13) is smaller than the volume of the second muffler chamber (14).

7. A ventilator according to claim 1, characterized in that The ventilator base (2) is provided with a guide bar (2.2), the guide bar (2.2) is located in the first part (9.1) of the second air inlet channel (9), and the guide bar (2.2) extends from the side wall of the ventilator base (2) to the second part (9.2) of the second air inlet channel (9); preferably, three guide bars (2.2) are provided in parallel, and the middle guide bar (2.2) is higher than the guide bars (2.2) on both sides.

8. A ventilator according to claim 2, characterized in that A vertically extending guide column (15) is further provided in the second part (9.2) of the second air inlet channel (9), and the guide column (15) is located directly below the wind resistance tube (12); the guide column (15) comprises a baffle (15.1), a first guide vane (15.2) and a second guide vane (15.3); the connection point between the first part (9.1) and the second part (9.2) is called a connection end, the first guide vane (15.2) is fixed to a side of the baffle (15.1) facing the connection end, and the second guide vane (15.3) is fixed to a side of the baffle (15.1) facing away from the connection end.

9. A ventilator according to claim 8, characterized in that A plurality of the first guide blades (15.2) are arranged in parallel, and a plurality of the second guide blades (15.3) are arranged radially.

10. A ventilator according to claim 9, characterized in that The number of the first guide vanes (15.2) is greater than the number of the second guide vanes (15.3).

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