A centrifugal impeller and a high specific speed energy-saving centrifugal dust removal fan

Abstract

The present invention discloses a centrifugal impeller and a high specific speed energy-saving centrifugal dust removal fan, wherein a centrifugal impeller comprises: a hub for mounting a rotating shaft; at least one set of blade assemblies is arranged on the hub, each set of blade assemblies comprises a plurality of blades arranged circumferentially along the hub; along the direction from the blade head to the blade tail, the blade comprises an arc segment and a straight segment, and the straight segment is arranged radially inclined relative to the hub; the inclination direction of each blade is consistent. The blades of the centrifugal impeller are combined blades of arc segments and straight segments, which effectively improve the flow of airflow, avoid airflow loss, obtain a larger airflow flow rate and meet the requirements of low noise. Therefore, the high specific speed energy-saving centrifugal dust removal fan using the centrifugal impeller can significantly reduce the volume of the whole equipment while increasing the specific speed, reduce the structural cost, and effectively increase the airflow flow rate delivered by the fan, filling the gap in the large flow and medium pressure spectrum of the national standard centrifugal fan.

Description

Technical Field

[0001] The invention belongs to the technical field of impellers, and in particular relates to a centrifugal impeller and a high specific speed energy-saving centrifugal dust removal fan. Background Art

[0002] At present, the large dust removal fans used in industrial dust removal fan systems are basically concentrated in the product range of 4-73 series with a specific speed of 73, 4-60 series with a specific speed of 60, and 5-48 and 6-48 series with a specific speed of 48. With the deepening of ultra-clean emission, the number of filter chambers increases, the filtration area increases, and the filtration wind speed drops from the original 1m / min to 0.7~0.8m / min. The dust removal air volume required by the dust removal system is increased and the system pressure will be reduced. Under the premise that the fan design speed remains unchanged, the specific speed of the fan model will be further increased, and the basic range is between 85~90. In this way, if the 4-73 or 4-60 series is still used, the fan operation point is bound to be in the large flow area, the impact loss increases, the operating efficiency deviates a lot from the optimal design point, and with the deterioration trend of the dust removal system, the resistance of the dust removal system tends to gradually increase. The 4-73 or 4-60 series fans used will not meet the high requirements of ultra-clean emission for dust removal air volume.

[0003] If the method of reducing the design speed of the fan by one gear is adopted for design and selection, the external dimensions will increase by more than 25% using the existing 4-73 and 4-60 series fans. Not only will the space occupied be large, the equipment cost will increase significantly, and the construction cost will also increase simultaneously.

[0004] Customers have high requirements for the overall performance of fans, but the cost must be as low as possible. In the face of increasingly competitive fan market, it is necessary to develop fan products that meet personalized requirements. Aiming at the fan series spectrum of existing national standard products, with the goal of high efficiency, energy saving and low noise, we fill the blank area in the spectrum and develop high specific speed energy-saving centrifugal dust removal fan products. Summary of the invention

[0005] In order to solve the technical problems raised in the background technology, the present invention provides a centrifugal impeller and a high specific speed energy-saving centrifugal dust removal fan.

[0006] The technical solution of the present invention is:

[0007] A centrifugal impeller comprises: a hub for mounting a rotating shaft; at least one set of blade assemblies is arranged on the hub, each set of blade assemblies comprises a plurality of blades arranged circumferentially along the hub; along the direction from the blade head to the blade tail, the blade comprises an arc segment and a straight segment, the straight segment is arranged radially inclined relative to the hub; the inclination direction of each blade is consistent.

[0008] Further preferably, the inlet installation angle of the blade is 20°~40°.

[0009] Further preferably, the ratio of the arc length of the arc segment to the length of the straight segment is 1:2.5.

[0010] Further preferably, each group of the blade assemblies includes a reinforcing plate for reinforcing the strength of the blades; the reinforcing plate is located between two adjacent blades and vertically connected to the two blades; the reinforcing plate extends from the blade head to the blade tail; and one end of the reinforcing plate near the blade head is arc-shaped.

[0011] Further preferably, the reinforcing plate is spaced apart from a side of the blade that faces away from the air inlet end of the impeller by a length that is 0.618 times the blade width.

[0012] Further preferably, two groups of the blade assemblies are provided, and the two groups of the blade assemblies are coaxially arranged back to back; a wheel disc is shared by two adjacent blade assemblies; both ends of the impeller are air inlet ends, and a wheel cover is provided on one side of the two blade assemblies located at the air inlet end of the impeller.

[0013] A high specific speed energy-saving centrifugal dust removal fan adopts any centrifugal impeller as described in claims 1-6.

[0014] Further preferred, it includes: adopting the centrifugal impeller described in claim 6; a casing body, with air inlet boxes respectively arranged on both sides, and the two sides of the casing body are connected with the air inlet boxes through the first air inlet; the centrifugal impeller is arranged in the casing body, and its air inlet end is connected with the first air inlet through the collector respectively; a rotating shaft passes through the casing body, the collector, and the centrifugal impeller in sequence, and is connected to the driving device; the air flow passes through the air inlet box, the first air inlet, the collector, and the air inlet end of the centrifugal impeller in sequence, and is then output from the radial outlet end of the centrifugal impeller and the radial outlet of the casing body in sequence.

[0015] Further preferably, the inlet of the air intake box is rectangular, and the aspect ratio of the rectangle is 1:4.

[0016] Further preferably, an adjusting door for adjusting the gas flow is provided at the inlet of the air intake box, and the adjusting door includes a plurality of adjusting door blades.

[0017] Further preferably, the regulating door blade is a shuttle-shaped hollow blade.

[0018] Further preferably, the number of the regulating door blades and the number of blades of the centrifugal impeller are prime numbers to each other.

[0019] Further preferably, the number of blades in each group of the blade assembly is 12 or 16, and the number of the adjusting door blades provided in each of the multi-leaf adjusting doors is 5 or 7.

[0020] The present invention provides a centrifugal impeller and a high specific speed energy-saving centrifugal dust removal fan, which have the following advantages and positive effects compared with the prior art:

[0021] The factors affecting the performance characteristics of a fan depend on the gas flow inside the impeller of the fan, and the internal gas flow that affects the impeller mainly depends on the form of the blades, including parameters such as the blade profile, the blade inlet and outlet installation angles, and the number of blades. The fan is generally operated under non-design conditions. When the gas enters the blade flow channel formed between two adjacent blades, it forms a certain angle with the blade to enter the blade flow channel. The angle is less than or greater than the blade inlet installation angle A1. The greater the deviation of the airflow, the greater the deviation of the angle, that is, the more serious the separation of the boundary layer. Due to the existence of this angle, the airflow generates a vortex on the suction surface 305 of the blade. The absolute speed of the airflow and the relative speed of the airflow on the back side 306 of the blade are low. The vortex air mass can easily adhere to the back side 306 of the blade, which not only affects the performance of the fan and causes airflow disturbance losses, but also generates noise. From the simulation diagram (see Figure 8 and Fig. 9 ) It can be seen that the location where the vortex air mass is formed is generally in the area of ​​the trailing edge 307 of the suction surface of the blade, and the vortex in these places is more serious than that in other places.

[0022] 1. The centrifugal impeller of the present invention has a blade type including a combination of an arc segment and a straight segment along the direction from the blade head to the blade tail, which is conducive to ensuring that the inflow direction of the airflow and the blade inlet angle A1 are consistent as much as possible, so that the tendency of boundary layer separation is effectively controlled. Fig.10 ) It can be seen that the average flow velocity in the boundary layer is faster than the flow velocity in the thick boundary layer of the curved blade, so the uneven airflow deposition phenomenon is much more delayed than that of the curved blade, and the separation of the boundary layer is effectively controlled to avoid the formation of vortices at the trailing edge 307 of the blade suction surface 305. When the impeller rotates, due to the weakening of the airflow vortex on the suction surface 305, the adhesion phenomenon of the vortex air mass at the outlet of the blade suction surface 305 is greatly improved, which can ensure the long-term stable operation of the impeller and avoid airflow loss, thereby obtaining a larger airflow flow and meeting the requirements of low noise.

[0023] 2. After computer simulation test, refer to Fig.11 When the length of the front arc segment 301 and the length of the straight segment 302 are 1:2.5, the airflow scouring effect is better, which improves the fan performance. The impeller made of this type of combined blades can achieve a maximum efficiency of 88.5%.

[0024] 3. In the prior art, if the working efficiency of the centrifugal dust removal fan is to be improved without increasing the volume of the fan structure, the speed of the impeller has to be increased, which increases the vibration and noise of the fan. The centrifugal dust removal fan in the present invention adopts a centrifugal impeller, which can greatly reduce the volume of the whole equipment while increasing the specific speed, reduce the structural cost, and effectively increase the air flow rate delivered by the fan, filling the gap in the larger flow and medium pressure spectrum of the national standard centrifugal fan, meeting the higher requirements of ultra-clean emissions on the performance of the dust removal fan, and realizing the high efficiency, energy saving and low noise requirements of the dust removal fan. The maximum internal efficiency of the centrifugal dust removal fan provided by the present invention can reach 87.3%. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other features and advantages of the present invention will be more clearly understood through the following detailed description in conjunction with the accompanying drawings, in which:

[0026] Figure 1 Schematic diagram of the centrifugal impeller in Example 1 of the present invention;

[0027] Figure 2 for Figure 1 Schematic diagram of a centrifugal impeller with the wheel cover removed;

[0028] Figure 3 for Figure 2 A top view of

[0029] Figure 4 This is a schematic structural diagram of a centrifugal dust removal fan in Example 2 of the present invention;

[0030] Figure 5 It is a cross-sectional view of the centrifugal dust removal fan in Example 2 of the present invention;

[0031] Figure 6 This is a schematic diagram of the structure of the adjustable door blade in Example 2 of the present invention;

[0032] Figure 7 for Figure 6 Left view of

[0033] Figure 8 A schematic diagram of the vortex of a circular arc backward inclined blade in the prior art;

[0034] Fig. 9 It is a schematic diagram of the vortex of a straight backward inclined blade in the prior art;

[0035] Fig.10 Schematic diagram of the vortex of the blades of the centrifugal impeller in the present invention;

[0036] Fig.11 This is a pressure gradient simulation cloud diagram of the centrifugal impeller in the present invention.

[0037] Explanation of symbols:

[0038] 1-impeller; 2-hub; 3-blade; 301-arc segment; 302-straight segment; 303-blade head; 304-blade tail; 305-blade suction surface; 306-blade back; 307-blade trailing edge; 4-inlet end; 5-reinforcement plate; 6-wheel disc; 7-wheel cover; 8-casing body; 9-first air inlet; 10-air inlet box; 11-inlet of air inlet box; 12-adjusting door; 13-adjusting door blade; 14-collector; 15-main shaft; 16-casing air outlet. DETAILED DESCRIPTION

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0040] In order to simplify the drawings, only the parts related to the present invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0041] Reference Figure 1-3 The present embodiment provides a centrifugal impeller 1, comprising: a hub 2 for mounting a rotating shaft; at least one set of blade assemblies is arranged on the hub 2, each set of blade assemblies comprises a plurality of blades 3 arranged circumferentially around the hub 2; along the direction from the blade head 303 to the blade tail 304 of the blade 3, the blade 3 comprises an arc segment 301 and a straight segment 302, the straight segment 302 is arranged radially inclined relative to the hub 2; the inclination direction of each blade 3 is consistent.

[0042] The centrifugal impeller 1 of the present invention has a blade type including a combination of an arc segment 301 and a straight segment 302 along the direction from the blade head 303 to the blade tail 304, which is conducive to ensuring that the inflow direction of the airflow and the blade inlet angle A1 are consistent as much as possible, so that the tendency of boundary layer separation is effectively controlled. Fig.10) It can be seen that the average flow velocity in the boundary layer is faster than the flow velocity in the thick boundary layer of the curved blade, so the uneven airflow deposition phenomenon is much more delayed than that of the curved blade, and the separation of the boundary layer is effectively controlled to avoid the formation of vortex at the trailing edge 307 of the blade suction surface 305. When the impeller rotates, due to the weakening of the airflow vortex on the suction surface 305, the adhesion phenomenon of the vortex air mass at the outlet of the blade suction surface is greatly improved, which can ensure the long-term stable operation of the impeller and avoid airflow loss, so as to obtain a larger airflow flow and meet the requirements of low noise.

[0043] Further, in this embodiment, refer to Figure 1-3 , from the blade head 303 to the blade tail 304 of the blade 3, the width of the arc segment 301 of the blade 3 gradually extends toward the air inlet end of the impeller to increase to the same width as the straight segment 302, so that the blade head 303 of the blade is parabolic, so that when the blade rotates, the gas is obliquely inserted into the blade flow channel between the two blades 3, thereby increasing the suction capacity of the impeller. Of course, in other embodiments, the shape of the blade head is not limited to the above, and the shape of the blade head can be changed according to specific needs.

[0044] In this embodiment, see Figure 3 , the inlet installation angle A1 of the blade is 20°~40°. The inlet installation angle A1 of the blade is the angle between the tangent at the inlet of the blade and the circumferential direction. A reasonable inlet installation angle is selected to ensure that the inflow direction of the airflow and the inlet angle of the blade are consistent as much as possible, or slightly larger than the inlet angle of the blade. The preferred inlet installation angle of the blade in this embodiment is 22°, so that there is no offset between the airflow and the blade when the airflow flows in, reducing the impact loss at the airflow inlet and effectively controlling the tendency of boundary layer separation. Of course, in other embodiments, there is no limitation on the specific angle of the inlet installation angle, for example, the inlet installation angle can also be 30°.

[0045] In this embodiment, the blades of the blade assembly are backward blades, that is, the outlet installation angle A2 of the blade is less than 90°, specifically 48°. The outlet installation angle A2 of the blade is the angle between the tangent direction of the blade outlet end and the tangent direction of the circumference of the blade outlet end. The backward blade has a small curvature and conforms to the movement direction of the gas under the action of centrifugal force. The collision between the air and the blade is very small, so the energy loss and noise are small, and the efficiency is high. Of course, in other embodiments, the size of the outlet installation angle of the blade is not limited to the above, for example, it can also be greater than 90°, so that the blade of the blade assembly is a forward blade.

[0046] In this embodiment, see Figure 3The preferred ratio of the arc length of the arc segment 301 to the length of the straight segment 302 is 1:2.5. According to computer simulation experiments, when the arc length of the arc segment 301 to the length of the straight segment 302 is 1:2.5, the airflow scouring effect is optimal, which is beneficial to improving the fan performance, and its maximum efficiency can reach 88.5%. Of course, in other embodiments, the ratio of the arc length of the arc segment to the length of the straight segment is not limited to the above, and the ratio can be reasonably adjusted according to actual conditions.

[0047] In this embodiment, see Figure 1 , 2 , each blade assembly includes a reinforcing plate 5 for reinforcing the strength of the blades; the reinforcing plate 5 is located between two adjacent blades 3 and vertically connected to the two blades 3, the reinforcing plate 5 is beneficial to improving the rigidity of the blades, and avoiding the "V"-shaped bending of the blades due to insufficient rigidity, which leads to an imbalance of the impeller; wherein the reinforcing plate 5 extends from the blade head 303 to the blade tail 304 of the blade 3, so that when the airflow enters the flow channel between the two blades from the air inlet end, the extension direction of the reinforcing plate is consistent with the airflow direction, avoiding the reinforcing plate 5 affecting the airflow direction; further, one end of the reinforcing plate 5 located near the blade head 303 is in an arc shape, and in terms of airflow flow, the arc shape has little effect on the airflow flow. Of course, in other embodiments, the specific structural shape of the reinforcing plate is not limited to the above description or shown in the figure, and the structural shape of the reinforcing plate can be adjusted accordingly according to actual conditions.

[0048] Further, in this embodiment, refer to Figure 1 , 2 , along the direction of the blade width, the reinforcing plate 5 is 0.618 times the blade width length away from the side edge of the blade facing away from the impeller inlet end 4, that is, the reinforcing plate 5 is arranged on the side close to the impeller inlet end 4, and the position of 0.618 times the blade width is the golden section position of the blade 3. The reinforcing plate is welded at its golden section position, which effectively improves the rigidity of the blade 3 and makes the blade less stressed; and when the airflow is sucked into the impeller 1 from the impeller inlet end 4, the airflow exerts a stronger impact force on the side of the blade 3 close to the inlet end, so that the reinforcing plate 5 is arranged here, which can effectively prevent the blade from being deformed or vibrated due to excessive force. Of course, in other embodiments, the position where the reinforcing plate is arranged is not limited to the above description or shown in the figure, for example, it can also be arranged in the middle position of the blade along the blade width direction.

[0049] According to the air intake mode of the impeller, it is divided into single-intake impeller and double-intake impeller. When only one end of the impeller is the air intake end, it is a single-intake impeller; when both ends of the impeller are the air intake ends, it is a double-intake impeller.

[0050] According to whether the impeller has a wheel cover 7 and a wheel disc 6, there are three types of impellers: fully open, semi-open and fully closed.

[0051] For example, in this embodiment, see Figure 1-3Two sets of blade assemblies are arranged, and the two sets of blade assemblies are arranged coaxially and back to back; a wheel disk 6 is shared between two adjacent blade assemblies; both ends of the impeller are air inlet ends 4, and wheel covers 7 are provided on one side of the impeller air inlet end 4 on the two blade assemblies, forming a fully closed double-intake impeller.

[0052] Of course, in other embodiments, the structure of the centrifugal impeller is not limited to that described in this embodiment, and there are also various classification variations. For example, the wheel cover 7 on the blade assembly is removed on the basis of the embodiment, thereby forming a semi-open double-intake impeller; the wheel cover 7 and the wheel disc 6 on the blade assembly are removed on the basis of the embodiment, thereby forming a fully open double-intake impeller;

[0053] Of course, in other embodiments, the number of blade assemblies is not limited to the above. For example, based on the present embodiment, one set of blade assemblies is removed, that is, only one set of blade assemblies is provided, and one end of the blade assemblies is the air inlet end 4 of the impeller, so that the hub 2 and the set of blade assemblies together form a fully closed single-intake impeller. Further, the wheel cover 7 is removed to form a semi-open single-intake impeller.

[0054] Example 2

[0055] This embodiment provides a high specific speed energy-saving centrifugal dust removal fan, which adopts any one of the centrifugal impellers described above.

[0056] This embodiment uses the double-intake impeller in Embodiment 1 as an example to specifically illustrate the specific structure and excellent effects of a high specific speed energy-saving centrifugal dust removal fan. Of course, in other embodiments, other types of centrifugal impellers described above may also be used.

[0057] See also Figure 4-7 , the high specific speed energy-saving centrifugal dust removal fan further includes:

[0058] The casing body 8 has air inlet boxes 10 on both sides thereof, and both sides of the casing body 8 are connected to the air inlet boxes 10 through the first air inlet 9;

[0059] The double-intake impeller 1 is arranged in the casing body 8, and its air inlet end 4 is connected with the first air inlet 9 through the collector 14;

[0060] The rotating shaft 15 passes through the casing body 8, the collector 14, and the double-intake impeller 1 in sequence, and is connected to the driving device;

[0061] The airflow passes through the air inlet box 10, the first air inlet 9, the collector 14, the air inlet end 4 of the double-intake impeller 1 in sequence, and is then output from the radial air outlet end of the double-intake impeller 1 and the radial air outlet 16 of the casing body in sequence.

[0062] The centrifugal dust removal fan provided in this embodiment adopts a centrifugal impeller, which can greatly reduce the volume of the entire equipment while increasing the specific speed, effectively increasing the air flow rate delivered by the fan, filling the gap in the larger flow and medium pressure spectrum of national standard centrifugal fans, and meeting the higher requirements of ultra-clean emissions on the performance of dust removal fans, while achieving high efficiency, energy saving and low noise requirements of the dust removal fan.

[0063] Specifically, the casing body 8 is in a volute shape and shares side panels with the air intake box 10 on both sides, which is beneficial to reducing structural costs and reducing the axial size of the fan; at the same time, reinforcing ribs with appropriate spacing and heights are arranged on the outer sides of the side panels on both sides of the casing body 8, which greatly improves the casing rigidity and effectively resists the disturbance of the aerodynamic force on the casing when the impeller rotates.

[0064] Furthermore, in the present embodiment, the collector 14 is an arc-shaped collector, and the collector gradually converges along the axial direction to an approximate arc shape. The arc-shaped collector is beneficial for reducing airflow loss and guiding the airflow into the impeller with better flow conditions. Of course, in other embodiments, a cylindrical collector or a conical collector may also be selected.

[0065] Furthermore, in this embodiment, the inlet of the preferred air intake box 10 is rectangular, and the aspect ratio of the rectangle is 1:4, wherein the length of the rectangle is the side extending along the axial direction of the main shaft, and the axial dimension of the centrifugal dust removal fan is reduced as much as possible while ensuring that the centrifugal dust removal fan has the best gas flow efficiency, thereby reducing the overall size of the fan. After multiple experimental calculations, it is concluded that when the inlet aspect ratio of the air intake box is 1:4, the flow efficiency of the airflow is the highest; when the aspect ratio is less than 1:4, for example, 1:5, when the airflow changes from radial flow to axial flow and turns into the impeller after passing through the air intake box, the airflow is relatively rapid, resulting in airflow loss and affecting the airflow flow performance; when the aspect ratio is greater than 1:4, for example, 1:2, the axial dimension of the fan becomes larger, thereby increasing the overall size of the fan and failing to save floor space. Of course, in other embodiments, the inlet aspect ratio of the air intake box is not limited to the above.

[0066] In this embodiment, a regulating door 12 for regulating the gas flow is provided at the entrance of the air intake box 10, and the regulating door 12 includes a plurality of regulating door blades 13. Specifically, in this embodiment, the regulating door adopts a radial multi-leaf flap differential regulating door, and the transmission of the regulating door blades 13 generally adopts a rolling bearing with a diamond seat, and the gas flow entering the air intake box is adjusted by flipping a plurality of regulating door blades 13, and the regulating process is flexible and labor-saving. Of course, in other embodiments, the type of regulating door is not limited to the above, for example, a round petal regulating door can also be adopted.

[0067] Further, in this embodiment, refer to Figure 6 , 7The preferred regulating door blade 13 is a shuttle-shaped hollow blade, which has less airflow resistance and better gas flow performance. Of course, in other embodiments, the specific structural form of the regulating door blade is not limited to the above.

[0068] In this embodiment, the number of the regulating door blades 13 and the number of the double-intake impeller blades 3 are prime numbers to each other. If there is a common divisor between the two, when the airflow flows from the air inlet box into the impeller, airflow coupling vibration will occur, thereby consuming airflow energy, resulting in a decrease in wind pressure, and pulsating airflow, causing mechanical vibration and noise in the fan, which affects its service life.

[0069] Furthermore, the number of impeller blades is an important parameter directly related to the aerodynamic performance of the fan. Too few blades will cause secondary vortexes in the impeller flow channel, resulting in pressure loss; while too many blades will reduce the effective flow area of ​​the gas, causing the impeller inlet impact loss and friction loss along the way to increase, and will also increase the load on the impeller main shaft, reducing the total pressure and efficiency of the fan. Among them, when the number of blades 3 set in the impeller of the double-intake dust removal fan is generally 10, 12, 14, or 16, the fan efficiency is relatively high. In this embodiment, through experimental calculations, it is concluded that when the number of blades in each blade assembly is 12 or 16, the airflow performance of the centrifugal dust removal fan is optimal; the number of adjusting door blades 13 and the number of blades 3 of the impeller are prime numbers to each other, so that the number of adjusting door blades 13 set for each multi-leaf adjusting door is 5 or 7. Of course, in other embodiments, the number of impeller blades and the number of adjusting door blades are not limited to the above, and can be reasonably adjusted according to actual applications.

[0070] In order to fully demonstrate the advantages of a centrifugal dust removal fan provided by the present invention, under the premise of equal total pressure, equal dust removal air volume output and the same specific speed, the following uses the 4-73 series fan in the prior art (for example, the 4-73 №24.5F centrifugal dust removal fan, where 4 represents the pressure coefficient of level 4, and 73 is the specific speed of the fan) and the same type of centrifugal dust removal fan in the present invention for performance comparison analysis (where the same type represents the same pressure coefficient, and the specific speed can reach a large air volume fan of more than 73):

[0071] For example: The design parameters of a steelmaking desulfurization and dust removal fan after ultra-clean emission are: atmospheric pressure 101325Pa, dust removal air volume Q=900,000 m3 / h, total pressure Pt=5000Pa, fan inlet pressure Pin=-4500Pa, medium temperature t=120℃, medium density ρ=1.293kg / Nm3, operating density ρv=0.853kg / m3.

[0072] The following table gives a dimensional performance comparison of the two fans: (fan speed n = 960rpm)

[0073] Fan Model Impeller diameter (mm) Flow rate (m3 / h) Total pressure (Pa) Fan internal efficiency (%) Fan effective power (KW) 4-73№24.5F 2450 900000 5030 84.2 1494 The present invention 2350 900000 5092 87.3 1458 deviation(%) -4.08 0 +1.23 +3.68 -2.41

[0074] It can be seen from the above table that, under the premise of meeting the same flow rate, total pressure and specific speed, the centrifugal dust removal fan in the present invention is 3.68% more efficient than the 4-73№24.5F fan in the prior art, and the effective power of the fan is reduced by 2.41%. In addition, the impeller diameter of the fan of the present invention is reduced by 100 mm, and the volume of the fan is reduced, which not only reduces materials and saves manufacturing costs, but also reduces the flywheel torque of the impeller rotor, shortens the start-up time of the fan, and at the same time increases the first-order critical speed of the rotor, thereby enhancing the reliability of the fan rotor.

[0075] Let's compare the inlet and outlet area ratios of the two fans:

[0076] Fan 4-73 №24.5F The present invention deviation(%) Air box inlet size (mm) 1360×3800×2 950×3800×2 Casing outlet size (mm) 3022×2250 2789×1880 Exit width ratio b2 / D2 25 30 Blade inlet width ratio b1 / D2 33 37.7 Blade inner diameter ratio D1 / D2 74 69.5 Fan outlet to inlet area ratio 0.6578 0.7262 +10.4% Impeller outlet to inlet area ratio 1.02375 1.14497 +11.84%

[0077] As can be seen from the above table, to meet the same flow rate and total pressure, the fan provided by the present invention can provide higher static pressure than the fan of model 4-73№24.5F in the prior art. In other words, to meet the same static pressure value, the fan of this patent can be selected with a smaller volume and better performance. Static pressure is a symbol of the ability of the fan to overcome the resistance along the system pipe network and the local resistance.

[0078] Based on the above comparison results, in other words, under the premise that the fan design speed is equal, among the same type of fans, the centrifugal dust removal fan of the present invention provides a larger dust removal air volume, can achieve a higher specific speed, and has a smaller overall size, thereby reducing the structural cost.

[0079] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the protection scope of the present invention.

Claims

1. A high specific speed energy-saving centrifugal dust removal fan, characterized in that: A centrifugal impeller is provided, the centrifugal impeller includes a hub for mounting a rotating shaft; at least one set of blade assemblies is provided on the hub, and each set of blade assemblies includes a plurality of blades arranged around the hub in a circumferential direction; Along the direction from the blade head to the blade tail, the blade includes an arc segment and a straight segment, and the straight segment is radially inclined relative to the hub; the inclination direction of each blade is consistent; The casing body has air inlet boxes on both sides thereof, and the two sides of the casing body are connected to the air inlet boxes through the first air inlet; The centrifugal impeller is disposed in the casing body, and its air inlet end is connected with the first air inlet through a collector; A rotating shaft, which sequentially passes through the casing body, the collector, and the centrifugal impeller, and is connected to a driving device; The airflow passes through the air inlet box, the first air inlet, the collector, and the air inlet end of the centrifugal impeller in sequence, and then is output from the radial air outlet end of the centrifugal impeller and the radial air outlet of the casing body in sequence; The inlet of the air intake box is rectangular, and the aspect ratio of the rectangle is 1:4; An adjusting door for adjusting the gas flow is provided at the inlet of the air inlet box, and the adjusting door includes a plurality of adjusting door blades; The casing body is in a volute shape and shares a side plate with the air inlet boxes on both sides. Ribs are arranged on the outer sides of the side plates on both sides of the casing body.

2. The high specific speed energy-saving centrifugal dust removal fan according to claim 1 is characterized in that: The inlet installation angle of the blade is 20°~40°.

3. The high specific speed energy-saving centrifugal dust removal fan according to claim 1 is characterized in that: The ratio of the arc length of the arc segment to the length of the straight segment is 1:2.

5.

4. The high specific speed energy-saving centrifugal dust removal fan according to claim 1 is characterized in that: Each group of blade assemblies includes a reinforcing plate for reinforcing the strength of the blades; the reinforcing plate is located between two adjacent blades and vertically connected to the two blades; the reinforcing plate extends from the blade head to the blade tail; one end of the reinforcing plate near the blade head is in an arc shape.

5. The high specific speed energy-saving centrifugal dust removal fan according to claim 4 is characterized in that: Along the blade width direction, the reinforcing plate is spaced apart from a side of the blade facing away from the air inlet end of the centrifugal impeller by a length that is 0.618 times the blade width.

6. The high specific speed energy-saving centrifugal dust removal fan according to claim 1, characterized in that: Two groups of blade assemblies are provided, and the two groups of blade assemblies are coaxially arranged back to back; a wheel disc is shared by two adjacent groups of blade assemblies; both ends of the centrifugal impeller are air inlet ends, and wheel covers are provided on one side of the air inlet end of the centrifugal impeller on the two groups of blade assemblies.

7. The high specific speed energy-saving centrifugal dust removal fan according to claim 1 is characterized in that: The regulating door blade is a shuttle-shaped hollow blade.

8. The high specific speed energy-saving centrifugal dust removal fan according to claim 1, characterized in that: The number of the regulating door blades and the number of the centrifugal impeller blades are mutually prime numbers.

9. The high specific speed energy-saving centrifugal dust removal fan according to claim 8, characterized in that: The number of blades in each group of the blade assembly is 12 or 16, and the number of the regulating door blades arranged on each regulating door is 5 or 7.

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