A multi-stage centrifugal blower without surge

Abstract

The present invention discloses a non-surge multi-stage centrifugal blower, which includes an air intake casing, an air outlet casing, an intermediate casing, a main shaft and an impeller; an air volume sensor is provided at the outlet end of the air outlet casing; an exhaust pipe is provided on the air outlet casing; air intake and air outlet bearing seats are provided at both ends of the main shaft respectively; a vibration sensor is provided on the air outlet bearing seat; the impeller is connected to the main shaft in a transmission manner; a balancing disk is provided at the connection between the air outlet casing and the main shaft; a sealing cover is provided on the outer side of the balancing disk, and one end of the sealing cover is connected to the air outlet casing, and the other end is connected to the main shaft; a displacement sensor is provided at the connection between the sealing cover and the main shaft; a sealed chamber is formed between the sealing cover and the balancing disk; the sealed chamber is connected to the air intake casing through a return pipe. The present invention optimizes the gas reflux and sealing structure, which can not only overcome the damage to the equipment caused by the gap change caused by the bearing damage, but also avoid the damage to the equipment caused by the change of system resistance and the incompatibility of the blower pressure, so as to ensure the reliable operation of the blower.

Description

Technical Field

[0001] The invention belongs to the technical field of blowers, and in particular relates to a non-surge multi-stage centrifugal blower. Background Art

[0002] In the prior art, multi-stage centrifugal blowers have the advantages of low noise and high efficiency, and can be widely used in many occasions such as environmental protection chemical pneumatic transportation.

[0003] However, during operation, the axial force changes with the working conditions, and the fan pressure is particularly sensitive to the ambient temperature. High temperature will significantly reduce the fan pressure. If the fan pressure is less than or equal to the system resistance, it will cause the fan to surge and damage the fan. The impeller clearance of the multi-stage blower is small, and the main shaft length and other structures determine the poor rigidity of the rotor. It is easy to be damaged by parts such as bearings, causing the clearance to change, which will instantly cause the impeller seal to rub and scratch, thereby damaging the fan.

[0004] In order to balance the axial force under various working conditions, a balancing disc structure is used at the outlet end of the blower. The balancing disc is installed behind the end impeller of the blower rotor, so that the axial force borne by the balancing disc during operation is opposite to the total axial force of the blower, offsetting part of the axial force to achieve a self-balancing state. The method to deal with bearing damage is generally to use high-precision bearings to extend the bearing life as much as possible and reduce the frequency of equipment damage caused by bearing damage, but the cost is also high.

[0005] At present, there is no proprietary technology to overcome the blower surge damage caused by changes in system resistance or pressure reduction due to factors such as temperature and speed. There is also no relevant technology to solve the blower damage caused by changes in blower clearance due to bearing damage. Summary of the invention

[0006] The purpose of the present invention is to solve the technical problem in the prior art that the impeller and the casing seal are scratched and damaged due to changes in the gap caused by changes in system resistance or bearing damage, and to provide a non-surge multi-stage centrifugal blower to overcome the shortcomings of the prior art.

[0007] The present invention is achieved through the following technical solutions:

[0008] The present invention discloses a non-surge multi-stage centrifugal blower, which comprises a housing assembly, a main shaft and an impeller;

[0009] The housing assembly includes an air inlet housing, an air outlet housing and a plurality of intermediate housings arranged between the air inlet housing and the air outlet housing, the intermediate housing is provided with a chamber, an air volume sensor is provided at the outlet end of the air outlet housing, and an exhaust pipe with a pressure sensor and an automatic valve is provided at the outlet end of the air outlet housing;

[0010] The main shaft is arranged in the middle of the housing assembly, and the two ends of the main shaft are connected to the air intake housing and the air outlet housing through an air intake bearing seat and an air outlet bearing seat respectively; a vibration sensor is arranged on the air outlet bearing seat;

[0011] The impeller is correspondingly arranged in the chamber in the intermediate housing and is drivingly connected to the main shaft; a first gap is left between the impeller and the intermediate chamber;

[0012] A balancing disk with a sealing ring is provided at the connection between the air outlet housing and the main shaft; a sealing cover is provided on the outer side of the balancing disk, and one end of the sealing cover is connected to the air outlet housing, and the other end is connected to the main shaft; a second gap and a displacement sensor are left at the connection between the sealing cover and the main shaft; a sealed chamber is formed between the sealing cover and the balancing disk; the sealed chamber is communicated with the air intake housing through a return air pipe;

[0013] The air volume sensor, the pressure sensor, the vibration sensor, the displacement sensor and the automatic valve are electrically connected to the electric controller respectively.

[0014] Furthermore, a pressure diffuser is provided at the outlet end of the air outlet housing.

[0015] Furthermore, the outlet bearing seat has a built-in heavy-duty support bearing, and a third gap is left between the heavy-duty support bearing and a bearing side cover provided on one side of the outlet bearing seat; the heavy-duty support bearing slides in the third gap.

[0016] Furthermore, the outer peripheral wall and the outer side wall of the balancing disk are respectively labyrinth seals.

[0017] Furthermore, the air intake bearing seat is composed of two radial ball bearings, and a spacer sleeve is provided between the two radial ball bearings.

[0018] The present invention has a reasonable structure and can operate reliably, optimizes the gas reflux and sealing structure, can not only overcome the damage to the equipment caused by the gap change due to bearing damage, but also avoid the damage to the equipment caused by the change of system resistance and the incompatibility of the fan pressure, and ensures that the blower can operate reliably.

[0019] In order to reduce the wind noise generated by the rotation of the impeller, a coating is provided on the surface of the impeller in the present invention, and the coating of the present invention has excellent noise reduction and shock absorption performance.

[0020] The coating is prepared according to the following steps:

[0021] Step 1) Take the following raw materials in parts by weight: 100 parts of pure acrylic emulsion, 60 parts of deionized water, 8 parts of nano-silicon dioxide, 5 parts of nylon fiber, 3 parts of propylene glycol ethyl ether, 2 parts of expanded graphite, 1 part of carbon fiber, 1 part of silane coupling agent, 0.8 parts of talc, 0.5 parts of dimethyl silicone oil, and 0.1 parts of 2-aminoisobutanol;

[0022] Step 2) Add nano-silicon dioxide and expanded graphite to deionized water twice the weight of silicon dioxide in sequence, stir at 500 rpm for 5 minutes, then add talcum powder, continue stirring at 500 rpm for 3 minutes, and then perform ultrasonic dispersion treatment for 10 minutes to obtain a filler slurry;

[0023] Step 3) Add the pure acrylic emulsion to a high-speed disperser, disperse at 3000 rpm for 2 min, then add the filler slurry, nylon fiber and carbon fiber, and continue to disperse at 3000 rpm for 10 min to obtain liquid A;

[0024] Step 4) Propylene glycol ethyl ether, silane coupling agent, dimethyl silicone oil and 2-aminoisobutanol are added to the remaining deionized water in sequence, and stirred at 1000 rpm for 5 minutes to obtain liquid B;

[0025] Step 5) Add liquid B to liquid A and stir at 500 rpm for 10 min to prepare a coating;

[0026] Step 6) Apply the coating to the impeller surface, dry at 80℃ for 15 minutes, and then cool to room temperature naturally.

[0027] Preferably, the silane coupling agent is KH550.

[0028] Preferably, the ultrasonic power is 500W.

[0029] Compared with the prior art, the effects of the present invention mainly include but are not limited to the following aspects:

[0030] The blower can be double protected against the change of the blower gap through the pressure displacement control system, so as to prevent the blower from further damage due to damage to the bearing and other parts;

[0031] The blower can provide alarm and pressure relief protection for the equipment through vibration and air volume control system;

[0032] It saves labor and time, is convenient and fast, thus greatly extending the trouble-free operation time of the blower, enhancing the reliability of the blower, and improving the operating efficiency of the blower.

[0033] The actuator and control device of the monitoring device are installed in an obvious and convenient position outside the blower casing, which is convenient for timely observation and adjustment of the blower's operating status and user convenience.

[0034] The impeller is coated with paint, which has good noise reduction and shock absorption performance and strong adhesion; the coating has a porous structure, and during the propagation of sound, it causes the air in the pores to move and rub against the pore walls. Due to the viscosity and heat conduction effects, the sound energy is converted into heat energy and dissipated, thereby achieving noise reduction and shock absorption performance; nano-silicon dioxide can form a stable structure in the coating and fill the graphite pores to form a stronger coating structure; nylon fiber and carbon fiber have good flame retardant and water absorption properties, and can be dispersed in the resin to form a network pore structure. During the sound wave conduction process, the sound energy is converted into heat energy, thereby achieving a noise reduction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic front cross-sectional view of the structure of the present invention.

[0036] Figure 2 It is a schematic left view of the structure of the present invention.

[0037] Figure 3 This Figure 1 A schematic enlarged view of the structure at center.

[0038] Figure 4 This Figure 1 A schematic enlarged view of the structure at B in the middle.

[0039] Figure 5 This Figure 1 Schematic enlargement of the structure at C in the middle.

[0040] Figure 6 This Figure 1 Schematic enlargement of the structure at D in the middle.

[0041] In the figure, 1, return air pipe, 2, outlet bearing seat, 3, support bearing, 4, spacer, 5, displacement sensor, 6, sealing cover, 7, balancing plate, 8, outlet casing, 9, impeller, 10, main shaft, 11, first gap, 12, intermediate casing, 13, intake casing, 14, intake bearing seat, 15, radial ball bearing, 16, labyrinth seal, 17, vibration sensor, 18, air volume sensor, 19, diffuser, 20, exhaust pipe, 21, automatic valve, 22, pressure sensor, 23, bearing side cover, 24, third gap, 25, second gap, 26, sealed chamber. DETAILED DESCRIPTION

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Example 1

[0044] Reference Figures 1 to 6 The present invention discloses a non-surge multi-stage centrifugal blower, which comprises a housing assembly, a main shaft 10 and an impeller 9;

[0045] The housing assembly includes an air intake housing 13 and an air outlet housing 8 which are interconnected, and a plurality of intermediate housings 12 arranged between the air intake housing 13 and the air outlet housing 8; a chamber is arranged in the intermediate housing 12; an air volume sensor 18 is arranged at the outlet end of the air outlet housing 8; an exhaust pipe 20 with a pressure sensor 22 and an automatic valve 21 is arranged at the outlet end of the air outlet housing 8;

[0046] The main shaft 10 is arranged in the middle of the housing assembly, and the two ends of the main shaft 10 are connected to the air intake housing 13 and the air outlet housing 8 through the air intake bearing seat 14 and the air outlet bearing seat 2 respectively; the air outlet bearing seat 2 is provided with a vibration sensor 17;

[0047] The impeller 9 is correspondingly arranged in the chamber in the intermediate housing 12 and is drivingly connected to the main shaft 10; a first gap 11 is left between the impeller 9 and the intermediate chamber;

[0048] A balancing disc 7 with a sealing ring is provided at the connection between the air outlet housing 8 and the main shaft 10; a sealing cover 6 is provided on the outer side of the balancing disc 7, and one end of the sealing cover 6 is connected to the air outlet housing 8, and the other end is connected to the main shaft 10; a second gap 25 and a displacement sensor 5 are left at the connection between the sealing cover 6 and the main shaft 10; a sealed chamber 26 is formed between the sealing cover 6 and the balancing disc 7; the sealed chamber 26 is communicated with the air intake housing 13 through the return air pipe 1;

[0049] The air volume sensor 18 , the pressure sensor 22 , the vibration sensor 17 , the displacement sensor 5 and the automatic valve 21 are electrically connected to the electronic controller respectively.

[0050] Furthermore, a diffuser pipe 19 is provided at the outlet end of the gas outlet casing 8 .

[0051] Furthermore, the outlet bearing seat 2 has a built-in heavy-duty support bearing 3 , and a third gap 24 is left between the heavy-duty support bearing 3 and a bearing side cover 23 provided on one side of the outlet bearing seat 2 ; the heavy-duty support bearing 3 slides in the third gap 24 .

[0052] Furthermore, the outer peripheral wall and the outer side wall of the balancing disc 7 are respectively labyrinth seals 16 .

[0053] Furthermore, the intake bearing seat 14 is composed of two radial ball bearings 15 , and a spacer sleeve 4 is provided between the two radial ball bearings 15 .

[0054] The present invention has a reasonable structure and can operate reliably, optimizes the gas reflux and sealing structure, can not only overcome the damage to the equipment caused by the gap change due to bearing damage, but also avoid the damage to the equipment caused by the change of system resistance and the incompatibility of the fan pressure, and ensures the reliable operation of the blower.

[0055] Compared with the prior art, the present invention has the following effects:

[0056] The blower can be double protected against the change of the blower gap through the pressure displacement control system, so as to prevent the blower from further damage due to damage to the bearing and other parts;

[0057] The blower can provide alarm and pressure relief protection for the equipment through vibration and air volume control system;

[0058] It saves labor and time, is convenient and fast, thus greatly extending the trouble-free operation time of the blower, enhancing the reliability of the blower, and improving the operating efficiency of the blower.

[0059] The actuator and control device of the monitoring device are installed in an obvious and convenient position outside the blower casing, which is convenient for timely observation and adjustment of the blower's operating status and user convenience.

[0060] The bearing damage protection of the present invention is realized by a pressure sensor. When the bearing 15 or the bearing 3 is damaged suddenly, the bearing loses position control due to the damage of the retainer, causing the bearing rolling element to contact the inner and outer rings, and the position of the inner hole and the outer ring changes, causing the gap S between the hard support mechanism and the main shaft to become smaller. When S is equal to 50% of the assembly gap J, the sensor sends a signal, lights up and sounds an alarm, at this time, the hard support begins to contact the main shaft; if the gap continues to change, when S is equal to 80% of the assembly gap J, the displacement sensor 5 sends a signal to open the system automatic valve 21, and then cut off the power supply of the main motor.

[0061] The non-surge protection of the present invention can be realized by an air volume sensor. When the fan output air volume is less than 40% of the set air volume, the fan will vibrate due to the turbulence of the air flow inside the shell, and the sensor will transmit a signal to the control system to alarm; when the fan output air volume is less than 20% of the set air volume, the fan will vibrate violently due to the turbulence of the air flow inside the shell, and the air volume sensor will transmit a signal to the control system to open the automatic valve and then cut off the power supply of the main motor.

[0062] The non-surge protection of the present invention can also be achieved through a vibration sensor. When the fan output air volume is less than 40% of the set air volume, the fan will vibrate due to the turbulent air flow inside the shell. When the vibration value of the blower is higher than 7.1mm / s, the vibration sensor transmits a signal to the control system to alarm; when the fan output air volume is less than 20% of the set air volume, the fan will vibrate violently due to the turbulent air flow inside the shell. When the vibration value of the blower is higher than 11.2mm / s, the vibration sensor transmits a signal to the control system, and the control system sends a signal to open the system drain valve and then cut off the power supply of the main motor.

[0063] Example 2

[0064] In order to reduce the wind noise generated by the rotation of the impeller, a coating is provided on the surface of the impeller in the present invention, and the coating of the present invention has excellent noise reduction and shock absorption performance.

[0065] The coating is prepared according to the following process:

[0066] 1) Take the following raw materials in parts by weight: 100 parts of pure acrylic emulsion, 60 parts of deionized water, 8 parts of nano-silicon dioxide, 5 parts of nylon fiber, 3 parts of propylene glycol ethyl ether, 2 parts of expanded graphite, 1 part of carbon fiber, 1 part of silane coupling agent (KH550), 0.8 parts of talc, 0.5 parts of dimethyl silicone oil, and 0.1 parts of 2-aminoisobutanol;

[0067] 2) Add nano-silica and expanded graphite to deionized water twice the weight of silica in sequence, stir at 500 rpm for 5 minutes, then add talcum powder, continue stirring at 500 rpm for 3 minutes, and then disperse with 500W ultrasonic wave for 10 minutes to prepare filler slurry;

[0068] 3) Add the pure acrylic emulsion to a high-speed disperser and disperse it at 3000 rpm for 2 min, then add the filler slurry, nylon fiber and carbon fiber, and continue to disperse it at 3000 rpm for 10 min to obtain liquid A;

[0069] 4) Propylene glycol ethyl ether, silane coupling agent, dimethyl silicone oil and 2-aminoisobutyl alcohol were added to the remaining deionized water in sequence, and stirred at 1000 rpm for 5 minutes to obtain liquid B;

[0070] 5) Add liquid B to liquid A and stir at 500 rpm for 10 min to prepare the coating;

[0071] 6) Apply the coating to the impeller surface, dry at 80℃ for 15 minutes, and then cool to room temperature naturally.

[0072] The coating performance test of the present invention:

[0073] Coating thickness: 800μm;

[0074] Under the condition of high-frequency noise 2000Hz, the sound insulation is 18dB;

[0075] Adhesion (GB / T9286-1998): Level 1;

[0076] Heat resistance (GB / T1735): no blistering, peeling and cracking;

[0077] Abrasion resistance (750g, 500r) / mg: 0.13.

[0078] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be construed as limitations on the present invention. Those of ordinary skill in the art can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A non-surge multi-stage centrifugal blower, comprising a housing assembly, a main shaft (10) and an impeller (9); The housing assembly comprises an air intake housing (13), an air outlet housing (8) and a plurality of intermediate housings (12) arranged between the air intake housing (13) and the air outlet housing (8), wherein a chamber is arranged in the intermediate housing (12); the characteristics are: An air volume sensor (18) is provided at the outlet end of the air outlet housing (8); an exhaust pipe (20) with a pressure sensor (22) and an automatic valve (21) is provided at the outlet end of the air outlet housing (8); The main shaft (10) is arranged in the middle of the housing assembly, and the two ends of the main shaft (10) are respectively connected to the air intake housing (13) and the air outlet housing (8) through an air intake bearing seat (14) and an air outlet bearing seat (2); a vibration sensor (17) is provided on the air outlet bearing seat (2); The impeller (9) is correspondingly arranged in the chamber in the intermediate casing (12) and is drivingly connected to the main shaft (10); a first gap (11) is left between the impeller (9) and the chamber in the intermediate casing (12); A balancing disk (7) with a sealing ring is provided at the connection between the air outlet housing (8) and the main shaft (10); a sealing cover (6) is provided on the outer side of the balancing disk (7), and one end of the sealing cover (6) is connected to the air outlet housing (8), and the other end is connected to the main shaft (10); a second gap (25) and a displacement sensor (5) are left at the connection between the sealing cover (6) and the main shaft (10); a sealed chamber (26) is formed between the sealing cover (6) and the balancing disk (7); the sealed chamber (26) is communicated with the air intake housing (13) through the return air pipe (1); The air volume sensor (18), the pressure sensor (22), the vibration sensor (17), the displacement sensor (5) and the automatic valve (21) are electrically connected to the electronic controller respectively; The outlet bearing seat (2) has a built-in heavy-duty support bearing (3), and a third gap (24) is left between the heavy-duty support bearing (3) and a bearing side cover (23) provided on one side of the outlet bearing seat (2); the heavy-duty support bearing (3) slides in the third gap (24); The surface of the impeller (9) is provided with a coating, and the thickness of the coating is 500-1000 μm; The coating is prepared according to the following steps: Step 1) Take the following raw materials in parts by weight: 100 parts of pure acrylic emulsion, 60 parts of deionized water, 8 parts of nano-silicon dioxide, 5 parts of nylon fiber, 3 parts of propylene glycol ethyl ether, 2 parts of expanded graphite, 1 part of carbon fiber, 1 part of silane coupling agent, 0.8 parts of talc, 0.5 parts of dimethyl silicone oil, and 0.1 parts of 2-aminoisobutanol; Step 2) adding nano-silicon dioxide and expanded graphite to deionized water twice the weight of silicon dioxide in sequence, stirring at 500 rpm for 5 min, then adding talcum powder, stirring at 500 rpm for 3 min, and then performing ultrasonic dispersion treatment for 10 min to obtain a filler slurry; Step 3) adding the pure acrylic emulsion into a high-speed disperser, dispersing at 3000 rpm for 2 min, then adding filler slurry, nylon fiber and carbon fiber, and continuing to disperse at 3000 rpm for 10 min to obtain liquid A; Step 4) Propylene glycol ethyl ether, silane coupling agent, dimethyl silicone oil and 2-aminoisobutanol are added to the remaining deionized water in sequence, and stirred at 1000 rpm for 5 min to obtain feed solution B; Step 5) adding liquid B to liquid A, stirring at 500 rpm for 10 min to obtain a coating; Step 6) Apply the coating to the impeller surface, dry at 80°C for 15 minutes, and cool to room temperature naturally.

2. A non-surge multi-stage centrifugal blower according to claim 1, characterized in that: The outlet end of the gas outlet casing (8) is provided with a pressure diffuser (19).

3. The non-surge multi-stage centrifugal blower according to claim 1, characterized in that: The outer peripheral wall and the outer side wall of the balancing disc (7) are respectively labyrinth seals (16).

4. The non-surge multi-stage centrifugal blower according to claim 1, characterized in that: The air intake bearing seat (14) is composed of two radial ball bearings (15), and a spacer sleeve (4) is arranged between the two radial ball bearings (15).

5. The non-surge multi-stage centrifugal blower according to claim 1, characterized in that: The silane coupling agent is KH550.

6. The non-surge multi-stage centrifugal blower according to claim 1, characterized in that: The ultrasonic power is 500W.

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