CN111927823A

CN111927823A - Centrifugal impeller and high-specific-speed energy-saving centrifugal dust removal fan

Info

Publication number: CN111927823A
Application number: CN202010958408.5A
Authority: CN
Inventors: 朱红兵
Original assignee: Shanghai Baosteel Energy Service Co Ltd
Current assignee: Shanghai Baosteel Energy Service Co Ltd
Priority date: 2020-09-11
Filing date: 2020-09-11
Publication date: 2020-11-13

Abstract

The invention discloses a centrifugal impeller and a high-specific-speed energy-saving centrifugal dust removal fan, wherein the centrifugal impeller comprises: the hub is used for mounting the rotating shaft; the hub is provided with at least one group of blade assemblies, and each group of blade assemblies comprises a plurality of blades circumferentially arranged along the hub; the blade comprises an arc-shaped segment and a straight segment along the direction from the head to the tail of the blade, and the straight segment is radially and obliquely arranged relative to the hub; the direction of each blade pitch is the same. The blades of the centrifugal impeller are combined blades of arc-shaped segments and straight segments, so that the flow of air flow is effectively improved, the air flow loss is avoided, the larger air flow is obtained, and the requirement of low noise is met. Therefore, the high-specific-speed energy-saving centrifugal dust removal fan adopting the centrifugal impeller can greatly reduce the volume of the whole machine equipment while improving the specific speed, reduce the structural cost, effectively improve the air flow conveyed by the fan and fill the blank in a large-flow and medium-pressure type spectrum in a national standard centrifugal fan.

Description

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

Technical Field

The invention belongs to the technical field of impellers, and particularly relates to a centrifugal impeller and an energy-saving centrifugal dust removal fan with high specific speed.

Background

The large dust removing fans applied in the current industrial dust removing fan system are mostly concentrated in the product ranges of 4-73 series with the specific rotating speed of 73, 4-60 series with the specific rotating speed of 60 and 5-48 and 6-48 series with the specific rotating speed of 48. Along with the deep proceeding of ultra-clean discharge, the number of the filter bins is increased, the filter area is increased, the filter air speed is further reduced to 0.7-0.8 m/min from the original 1m/min, the dust removal air quantity required by a dust removal system is increased compared with the original one, the system pressure is reduced, the specific rotating speed of a fan model is further increased on the premise that the design rotating speed of the fan is not changed, and the basic range is 85-90. Thus, if 4-73 or 4-60 series fans are still adopted, the operating point of the fan is always in a large flow area, the impact loss is increased, the deviation of the operating efficiency from the optimal design point is more, the resistance of the dust removal system is gradually increased along with the degradation trend of the dust removal system, and the adopted 4-73 or 4-60 series fans cannot meet the higher requirement of ultra-clean discharge on the dust removal air volume.

If the design selection is carried out by adopting a method of reducing the design rotating speed of the first-gear fan, the appearance size is increased by more than 25 percent by adopting the existing 4-73 and 4-60 series fans, the occupied space is large, the equipment cost is obviously increased, and the construction cost is synchronously increased.

The overall performance of the fan is required to be high by customers, the manufacturing cost is required to be as low as possible, and in the fan market with increasingly increased competition, fan products meeting personalized requirements must be developed. Aiming at the fan series type spectrum of the existing national standard product, the aim of high efficiency, energy conservation and low noise is fulfilled, the blank area in the type spectrum is filled, and the high specific speed energy-saving centrifugal dust removal fan product is developed.

Disclosure of Invention

The invention provides a centrifugal impeller and an energy-saving centrifugal dust removal fan with high specific speed, which aims to solve the technical problems in the background technology.

The technical scheme of the invention is as follows:

a centrifugal impeller comprising: the hub is used for mounting the rotating shaft; the hub is provided with at least one group of blade assemblies, and each group of blade assemblies comprises a plurality of blades circumferentially arranged along the hub; in a head-to-tail direction of the blade, the blade comprises an arc-shaped segment and a straight segment, and the straight segment is radially obliquely arranged relative to the hub; the direction of each blade inclination is consistent.

Further preferably, the inlet installation angle of the blade is 20-40 °.

Further preferably, the arc length of the arc-shaped segment and the length of the straight segment are in a ratio of 1: 2.5.

Further preferably, each set of the blade assemblies includes a reinforcing plate for reinforcing the strength of the blade; the reinforcing plate is positioned between two adjacent blades and is vertically connected with the two blades; the reinforcing plate extends along the direction from the head to the tail of the blade; one end of the reinforcing plate, which is positioned near the blade head, is arc-shaped.

Further preferably, the reinforcing plate is spaced from a side of the blade facing away from the air inlet end of the impeller by a blade width length of 0.618 times.

Further preferably, two groups of the blade assemblies are arranged, and the two groups of the blade assemblies are coaxially arranged in an opposite manner; a wheel disc is shared between two adjacent blade assemblies; the impeller both ends are the inlet end, two all cover on the blade subassembly lies in one side of impeller inlet end and is equipped with the wheel cap.

An energy-saving centrifugal dust-removing fan with high specific speed, which adopts a centrifugal impeller as claimed in any one of claims 1-6.

Further preferred, comprising: using a centrifugal impeller as described in claim 6; the air inlet box is arranged on each of two sides of the machine shell body, and the two sides of the machine shell main body are communicated with the air inlet boxes through first air inlets; the centrifugal impeller is arranged in the machine shell main body, and the air inlet ends of the centrifugal impeller are respectively communicated with the first air inlet through a collector; the rotating shaft sequentially penetrates through the machine shell body, the current collector and the centrifugal impeller and is connected with a driving device; and the airflow sequentially passes through the air inlet box, the first air inlet, the collector and the air inlet end of the centrifugal impeller and then is sequentially output from the radial air outlet end of the centrifugal impeller and the radial air outlet of the machine shell body.

Further preferably, the inlet of the inlet box is rectangular, and the length-width ratio of the rectangle is 1: 4.

Further preferably, an inlet of the air inlet box is provided with an adjusting door for adjusting the flow of the gas, and the adjusting door comprises a plurality of adjusting door blades.

Further preferably, the adjusting gate blade is a shuttle-shaped hollow blade.

Further preferably, the number of the blades of the adjusting door and the number of the blades of the centrifugal impeller are prime numbers.

Further preferably, each group of the blade assemblies has 12 or 16 blades, and each multi-blade adjusting door is provided with 5 or 7 adjusting door blades.

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

the factors of the fan performance characteristics depend on the gas flow in the fan impeller, and the factors influencing the gas flow in the impeller mainly depend on the form of the blades, including parameters such as blade profile, blade inlet and outlet installation angle, blade number and the like; the fan generally operates under an off-design condition, when gas enters a blade flow channel formed between two adjacent blades, the gas and the blades form a certain angle to enter the blade flow channel, the angle is smaller or larger than a blade inlet installation angle A1, the larger the deviation of the gas flow is, the larger the deviation of the angle is, and the more serious the separation of a boundary layer is. Due to the existence of the 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 surface 306 of the blade are low, and vortex air mass is easy to adhere to the back surface 306 of the blade, so that the performance of a fan is affected, airflow disturbance loss is caused, and noise is also generated; as can be seen from the simulations (see fig. 8 and 9), the location of the vortex mass formation is generally in the region of the trailing edge 307 of the suction surface of the blade, where the vortices are more severe than elsewhere.

1. In the centrifugal impeller of the invention, the blades are in a blade form comprising a combination of arc-shaped segments and straight segments along the direction from the head to the tail of the blades, which is beneficial to ensuring that the inflow direction of airflow is consistent with the inlet angle A1 of the blades as far as possible, so that the separation trend of a boundary layer is effectively controlled, and as can be seen from a simulation diagram (see figure 10), the average flow speed in the boundary layer is faster than that in a thicker boundary layer when the blades are in an arc-shaped shape, so that the uneven airflow deposition phenomenon is delayed by a lot compared with the arc-shaped blades, the separation of the boundary layer is effectively controlled, and the vortex is prevented from being formed at the rear edge 307 of the suction surface 305 of. When the impeller rotates, because the airflow vortex on the suction surface 305 is weakened, the adhesion phenomenon of the vortex air mass at the outlet of the suction surface 305 of the blade is greatly improved, the impeller can be ensured to stably run for a long time, the airflow loss is avoided, and therefore, the requirements of large airflow flow and low noise can be met.

2. Through computer simulation tests, referring to fig. 11, when the arc length of the arc-shaped segment 301 of the front section and the length of the straight segment 302 are 1: 2.5, the air flow scouring effect is good, and the performance of the fan is improved. The impeller made of the combined blades has the highest efficiency of 88.5 percent.

3. In the prior art, on the premise of not increasing the structural volume of the fan, if the working efficiency of the centrifugal dust removal fan is to be improved, the rotating speed of an impeller has to be increased, but the vibration and noise of the fan are increased; the centrifugal dust removal fan provided by the invention adopts the centrifugal impeller, so that the specific speed is improved, the volume of the whole equipment can be greatly reduced, the structural cost is reduced, the airflow flow conveyed by the fan is effectively improved, the blank in a large-flow and medium-pressure type spectrum in a national standard centrifugal fan is filled, the higher requirement of ultra-clean discharge on the performance of the dust removal fan is met, the high-efficiency energy-saving and low-noise requirements of the dust removal fan are realized, and the highest internal efficiency of the centrifugal dust removal fan provided by the invention can reach 87.3%.

Drawings

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

FIG. 1 is a schematic view of a centrifugal impeller in embodiment 1 of the present invention;

FIG. 2 is a schematic view of the centrifugal impeller of FIG. 1 with the shroud removed;

FIG. 3 is a top view of FIG. 2;

FIG. 4 is a schematic structural view of a centrifugal dust removing fan in embodiment 2 of the present invention;

FIG. 5 is a sectional view of a centrifugal dust removing fan in example 2 of the present invention;

FIG. 6 is a schematic view showing the structure of a blade of an adjustment gate in embodiment 2 of the present invention;

FIG. 7 is a left side view of FIG. 6;

FIG. 8 is a prior art circular backward inclined blade vortex schematic;

FIG. 9 is a prior art straight plate backward raking blade vortex schematic;

FIG. 10 is a schematic view of the swirl of the blades of a centrifugal impeller according to the present invention;

FIG. 11 is a simulated cloud plot of the pressure gradient of a centrifugal impeller of the present invention.

Description of the symbols:

1-an impeller; 2-a hub; 3-a blade; 301-an arc segment; 302-straight segment; 303-leaf heads; 304-leaf tail; 305-blade suction side; 306-blade back; 307-blade trailing edge; 4-an air inlet end; 5-a reinforcing plate; 6-a wheel disc; 7-wheel cover; 8-a housing body; 9-a first air inlet; 10-an air inlet box; 11-inlet of the inlet box; 12-a regulating gate; 13-adjusting the gate blade; 14-a current collector; 15-a main shaft; 16-machine shell air outlet.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will be made with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.

For the sake of simplicity, the drawings only schematically show the parts relevant to the present invention, and they do not represent the actual structure as a product. In addition, in order to make the drawings concise and understandable, components having the same structure or function in some of the drawings are only schematically illustrated or only labeled. In this document, "one" means not only "only one" but also a case of "more than one".

Referring to fig. 1 to 3, the present embodiment provides a centrifugal impeller 1 including a hub 2 for mounting a rotating shaft; at least one group of blade assemblies is arranged on the hub 2, and each group of blade assemblies comprises a plurality of blades 3 which are arranged around the circumference of the hub 2; in the direction from the leading edge 303 to the trailing edge 304 of the blade 3, the blade 3 comprises an arc-shaped segment 301 and a straight segment 302, the straight segment 302 being arranged radially inclined with respect to the hub 2; the direction in which each blade 3 is inclined is the same.

In the centrifugal impeller 1 of the present invention, along the direction from the blade head 303 to the blade tail 304 of the blade 3, the blade 3 is in the form of a blade comprising a combination of an arc-shaped segment 301 and a straight segment 302, which is beneficial to ensure that the inflow direction of the air flow is consistent with the blade inlet angle a1 as much as possible, so that the separation tendency of the boundary layer is effectively controlled, as can be seen from the simulation (see fig. 10), the average flow speed in the boundary layer is faster than that in the thicker boundary layer of the arc-shaped blade, so that the uneven air flow deposition phenomenon is delayed a lot from that of the arc-shaped blade, and the separation of the boundary layer is effectively controlled, thereby preventing the vortex from forming at the trailing edge 307 of the suction. When the impeller rotates, the air vortex on the suction surface 305 is weakened, so that the adhesion phenomenon of the vortex air mass at the outlet of the suction surface of the blade is greatly improved, the impeller can be ensured to stably run for a long time, the air loss is avoided, and the requirements of large air flow and low noise can be met.

Further, in the present embodiment, referring to fig. 1-3, from the blade head 303 to the blade tail 304 of the blade 3, the width of the arc-shaped segment 301 of the blade 3 gradually extends and increases towards the air inlet end of the impeller to be as wide as the straight segment 302, so that the blade head 303 of the blade is in a parabolic shape, and when the blade rotates, air is obliquely inserted into the blade flow channel between two blades 3, thereby increasing the air 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.

In the present embodiment, referring to FIG. 3, the vane inlet setting angle A1 is 20-40. The inlet mounting angle A1 of the blade is the included angle between the tangent line at the inlet of the blade and the circumferential direction, and a reasonable inlet mounting angle is selected to ensure that the inflow direction of the airflow and the inlet angle of the blade are consistent as far as possible or slightly larger than the inlet angle of the blade. The preferred blade of this embodiment's import erection angle is 22, makes when the air current flows in and does not have the skew between the blade, reduces the impact loss of air current entry, effectively controls the trend of boundary layer separation. Of course, in other embodiments, the specific angle of the inlet mounting angle is not limited, for example, the inlet mounting angle may be 30 °.

In this implementation, the blade of blade subassembly is backward formula blade, and the export erection angle A2 of blade is less than 90 promptly, specifically is 48 the export erection angle A2 of blade and is the contained angle between the circumference tangential direction of blade exit end tangential direction and blade exit end, and backward formula blade's crookedness is less, accords with the direction of motion of gas under the centrifugal force effect moreover, and the striking between air and the blade is very little to energy loss and noise are less, and efficiency is higher. Of course, in other embodiments, the size of the outlet setting angle of the blade is not limited to the above, and may be, for example, greater than 90 °, so that the blade of the blade assembly is a forward blade.

In this embodiment, referring to fig. 3, the preferred ratio of the arc length of the arc-shaped segment 301 to the length of the straight segment 302 is 1: 2.5, and through computer simulation experiments, when the ratio of the arc length of the arc-shaped 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 performance of the fan, and the highest efficiency can reach 88.5%. Of course, in other embodiments, the ratio of the arc length of the arc-shaped segment to the length of the straight segment is not limited to the above, and the ratio can be adjusted reasonably according to practical situations.

In the present embodiment, referring to fig. 1 and 2, each set of blade assemblies includes a reinforcing plate 5 for reinforcing the strength of the blade; the reinforcing plate 5 is positioned between two adjacent blades 3 and is vertically connected with the two blades 3, the reinforcing plate 5 is favorable for improving the rigidity of the blades, and the unbalance of the impeller caused by the V-shaped bending of the blades due to insufficient rigidity of the blades is avoided; the reinforcing plate 5 extends along the direction from the blade head 303 to the blade tail 304 of the blade 3, so that when airflow enters a flow channel between two blades from the air inlet end, the extending direction of the reinforcing plate is consistent with the airflow direction, and the reinforcing plate 5 is prevented from influencing the airflow direction; the end of the further reinforcing plate 5 near the blade head 303 is in the shape of a circular arc, and the circular arc has a small influence on the airflow in terms of the airflow, but in other embodiments, the specific structural shape of the reinforcing plate is not limited to the above or shown in the drawings, and the structural shape of the reinforcing plate can be adjusted accordingly according to actual conditions.

Further, in the present embodiment, referring to fig. 1 and 2, in the blade width direction, the distance between the reinforcing plate 5 and the side edge of the blade on the side facing away from the air inlet end 4 of the impeller is 0.618 times of the blade width length, that is, the reinforcing plate 5 is disposed on the side close to the air inlet end 4 of the impeller, the 0.618 times of the blade width position is a golden separation position of the blade 3, and the reinforcing plate is welded at the golden separation position, so that the rigidity of the blade 3 is effectively improved and the stress applied to the blade is smaller; and when the air current is inhaled into impeller 1 from impeller inlet end 4, the air current produces stronger impact force to the one side that is close to the inlet end on blade 3 to set up reinforcing plate 5 here, can prevent effectively that the blade atress is too big and produce deformation or shake. Of course, in other embodiments, the position where the reinforcing plate is disposed is not limited to the above or shown in the drawings, and may be disposed at a middle position of the blade in the blade width direction, for example.

According to the air suction mode of the impeller, the single suction impeller and the double suction impeller are divided, and when only one end of the impeller is an air inlet end, the single suction impeller is adopted; when both ends of the impeller are air inlet ends, the impeller is a double-suction impeller;

the impeller is divided into three types of fully-open type, semi-open type and fully-closed type according to the existence of the impeller cover 7 and the impeller disc 6.

For example, in the present embodiment, referring to fig. 1-3, two sets of blade assemblies are provided, and the two sets of blade assemblies are disposed coaxially and oppositely; a wheel disc 6 is shared between two adjacent blade assemblies; both ends of the impeller are air inlet ends 4, and wheel covers 7 are arranged on one sides of the two impeller components, which are positioned at the air inlet ends 4 of the impeller, so that a fully-closed double-suction impeller is formed.

Of course, in other embodiments, the structure of the centrifugal impeller is not limited to that of the present embodiment, and there are various classification variations, such as removing the wheel cover 7 on the blade assembly based on the embodiment, so as to form a semi-open type double suction impeller; the wheel cover 7 and the wheel disc 6 on the blade assembly are removed on the basis of the embodiment, so that a full open type double-suction impeller is formed;

of course, in other embodiments, the number of blade assemblies is not limited to the above, for example, on the basis of the present embodiment, one group of blade assemblies is removed, that is, only one group 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 group of blade assemblies together form a fully closed single suction impeller. Further removal of the shroud 7 results in a semi-open single suction impeller.

Example 2

The embodiment provides an energy-saving centrifugal dust removal fan with a high specific speed, and any one of the centrifugal impellers is adopted.

In this embodiment, the double suction impeller in embodiment 1 is used as an example, and a specific structure and a good effect of the energy-saving centrifugal dust removal fan with a high specific speed are specifically described. Of course in other embodiments, other types of centrifugal impellers as described above may be used.

Referring to fig. 4-7, the high specific speed energy-saving centrifugal dust-removing fan further comprises:

the air inlet box 10 is respectively arranged on two sides of the machine shell body 8, and two sides of the machine shell body 8 are communicated with the air inlet box 10 through the first air inlet 9;

the double suction impeller 1 is arranged in the machine shell main body 8, and the air inlet ends 4 of the double suction impeller are respectively communicated with the first air inlet 9 through a collector 14;

a rotating shaft 15 which sequentially penetrates through the casing body 8, the current collector 14 and the double suction impeller 1 and is connected with a driving device;

the airflow sequentially passes through the air inlet box 10, the first air inlet 9, the current collector 14 and the air inlet end 4 of the double-suction impeller 1 and then is sequentially output from the radial air outlet end of the double-suction impeller 1 and the radial air outlet 16 of the machine shell body.

The centrifugal dust removal fan provided by the embodiment adopts the centrifugal impeller, the specific rotating speed is improved, the size of the whole machine equipment can be greatly reduced, the airflow flow conveyed by the fan is effectively improved, the blank in a large flow and medium pressure type spectrum in a national standard centrifugal fan is filled, the higher requirement of ultra-clean emission on the performance of the dust removal fan is met, and the high-efficiency, energy-saving and low-noise requirements of the dust removal fan are realized.

Specifically, the casing body 8 is volute-shaped and shares a side plate with the air inlet boxes 10 on both sides, which is beneficial to reducing the structural cost and reducing the axial size of the fan; meanwhile, the reinforcing rib plates with proper intervals and heights are arranged on the outer sides of the side plates on the two sides of the casing body 8, so that the rigidity of the casing is greatly improved, and the disturbance of aerodynamic force to the casing during the rotation of the impeller is effectively resisted.

Further, in this embodiment, the current collector 14 is an arc current collector, and the current collector gradually converges in an approximately arc shape along the axial direction, and the arc current collector is favorable for reducing the air flow loss, and the flow condition of guiding the air flow to the impeller is more preferable, but in other embodiments, a cylindrical current collector or a conical current collector may be used.

Further, in the present embodiment, it is preferable that the inlet of the intake box 10 is rectangular, and the length-width ratio of the rectangle is 1: and 4, the length of the rectangle is the side extending along the axial direction of the main shaft, and the axial size of the centrifugal dust removal fan is reduced as much as possible under the condition that the centrifugal dust removal fan is ensured to have optimal gas flow efficiency, so that the whole size of the fan is reduced. Through multiple experimental calculations, the flow efficiency of the airflow is highest when the length-width ratio of the inlet of the air inlet box is 1: 4; when the aspect ratio is less than 1: 4, for example, the ratio is 1: 5, when the airflow turns into an impeller from radial flow to axial flow after passing through the air inlet box, the airflow is relatively rapid, so that airflow loss is caused, and the airflow flowing performance is influenced; when the length-width ratio is greater than 1: 4, for example, 1: 2, the axial size of the fan becomes large, so that the overall size of the fan is increased, and the occupied area cannot be saved. Of course in other embodiments the inlet box inlet aspect ratio is not limited to that described above.

In this embodiment, an inlet of the air inlet box 10 is provided with an adjusting door 12 for adjusting the air flow, the adjusting door 12 includes a plurality of adjusting door blades 13, specifically, in this embodiment, the adjusting door is a radial multi-blade flap-type differential adjusting door, the transmission of the adjusting door blades 13 generally adopts a rolling bearing with a diamond seat, the adjusting door blades 13 are turned to adjust the air flow entering the air inlet box, and the adjusting process is flexible and labor-saving. Of course, in other embodiments, the type of adjustment gate is not limited to the above, and for example, a circular petal adjustment gate may be used.

Further, in the present embodiment, referring to fig. 6 and 7, the preferred damper blade 13 is a shuttle-shaped hollow blade, which has less resistance to gas flow and better gas flow performance. Of course, in other embodiments, the specific configuration of the adjustment gate blade is not limited to the above.

In the present embodiment, the number of the damper blades 13 and the number of the blades 3 of the double suction impeller are prime numbers to each other. If the air inlet box and the air inlet box have common divisor, when the air flows into the impeller from the air inlet box, the air flow coupling vibration can occur, so that the air pressure is reduced due to the consumption of the air flow energy, and the air flow generates pulsation, so that the fan generates mechanical vibration and noise, and the service life of the fan is influenced.

Furthermore, the number of blades of the impeller is an important parameter directly related to the aerodynamic performance of the fan, and the blade number is too small, so that a secondary vortex is generated in an impeller flow channel, and pressure loss is caused; the effective gas flow area is reduced by too many blades, so that the impact loss and the on-way friction loss of an impeller inlet are aggravated, the load of an impeller main shaft is increased, and the total pressure and the efficiency of the fan are reduced, wherein when the number of the blades 3 arranged in the impeller of the double-suction dust removal fan is generally 10, 12, 14 and 16, the fan efficiency is high, in the embodiment, through experimental calculation, when the number of the blades of each group of blade assemblies is 12 or 16, the airflow flowing performance of the centrifugal dust removal fan is optimal at the moment; the number of the adjusting gate blades 13 and the number of the blades 3 of the impeller are prime numbers, so that the number of the adjusting gate blades 13 arranged on each multi-blade adjusting gate is 5 or 7, and in other embodiments, the number of the impeller blades and the number of the adjusting gate blades are not limited to the above, and can be reasonably adjusted according to practical application.

In order to fully show the advantages of the centrifugal dust removal fan provided by the invention, on the premise of equal full pressure, equal dust removal air volume output and equal specific rotation speed, a 4-73 series fan (such as a centrifugal dust removal fan of 4-73 No. 24.5F type, wherein 4 represents a pressure coefficient of 4 grade, and 73 represents the specific rotation speed of the fan) in the prior art is adopted to perform performance comparison analysis with the centrifugal dust removal fan of the same type in the invention (wherein the same type represents the same pressure coefficient, and the specific rotation speed can reach a large air volume fan of more than 73):

examples are: the design parameters of the ultra-clean discharged rear fan of a certain steel-making desulfurization dust-removing fan are as follows: the air pressure is 101325Pa, the dedusting air quantity Q is 90 ten thousand m3/h, the total pressure Pt is 5000Pa, the fan inlet pressure Pin is-4500 Pa, the medium temperature t is 120 ℃, the medium density rho is 1.293kg/Nm3, and the working condition density rho is 0.853kg/m 3.

The following table gives a dimensional performance comparison of two fans: (Fan speed n is 960rpm)

It can be seen from the above table that, on the premise of satisfying the same flow rate, full pressure and specific speed, the centrifugal dust removal fan of the present invention has an efficiency improved by 3.68% compared with the fan of 4-73 No. 24.5F in the prior art, and the effective power of the fan is reduced by 2.41%, and the diameter of the fan impeller of the present invention is reduced by 100mm, and the volume of the fan is reduced, thereby not only reducing the material and saving the manufacturing cost, but also reducing the flywheel moment of the impeller rotor, shortening the starting time of the fan, and simultaneously improving the first-order critical speed of the rotor, and enhancing the reliability of the fan rotor.

Comparing the area ratio of the inlet and the outlet of the air inlet boxes of the two fans:

it can be seen from the above table that the fan provided by the present invention can provide higher static pressure than the fan of type 4-73 No. 24.5F in the prior art, while satisfying the same flow rate and full pressure. In other words, the fan can select smaller volume and has better performance by meeting the same static pressure value. And the static pressure is a mark for showing the capacity of the fan for overcoming the on-way resistance and the local resistance of a system pipe network.

In other words, on the premise of equal design rotating speed of the fans, the centrifugal dust removal fan provided by the invention has larger dust removal air quantity, higher attainable specific rotating speed and smaller external dimension, and reduces the structural cost.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, it is still within the scope of the present invention if they fall within the scope of the claims of the present invention and their equivalents.

Claims

1. A centrifugal impeller, comprising: the hub is used for mounting the rotating shaft; the hub is provided with at least one group of blade assemblies, and each group of blade assemblies comprises a plurality of blades circumferentially arranged along the hub;

in a head-to-tail direction of the blade, the blade comprises an arc-shaped segment and a straight segment, and the straight segment is radially obliquely arranged relative to the hub; the direction of each blade inclination is consistent.

2. A centrifugal impeller according to claim 1, wherein the inlet setting angle of the blades is 20 ° to 40 °.

3. The centrifugal impeller of claim 1, wherein the arc length of the arc-shaped segment to the length of the straight segment is 1: 2.5.

4. The centrifugal impeller of claim 1, wherein each set of said blade assemblies includes stiffening plates for stiffening said blade; the reinforcing plate is positioned between two adjacent blades and is vertically connected with the two blades; the reinforcing plate extends along the direction from the head to the tail of the blade; one end of the reinforcing plate, which is positioned near the blade head, is arc-shaped.

5. The centrifugal impeller of claim 4, wherein the stiffener plate is spaced from a side of the blade facing away from the inlet end of the impeller by a width length of 0.618 times the blade width in the direction of the width.

6. The centrifugal impeller of claim 1, wherein two sets of said vane assemblies are provided, the two sets of said vane assemblies being coaxially disposed opposite one another; a wheel disc is shared between two adjacent blade assemblies; the impeller both ends are the inlet end, two all be equipped with the wheel cap on the blade subassembly lies in one side of impeller inlet end.

7. An energy-saving centrifugal dust-removing fan with high specific speed, which is characterized in that a centrifugal impeller as claimed in any one of claims 1-6 is adopted.

8. The high specific speed energy-saving centrifugal dust removal fan according to claim 7, comprising:

using a centrifugal impeller as described in claim 6;

the air inlet box is arranged on each of two sides of the machine shell body, and the two sides of the machine shell main body are communicated with the air inlet boxes through first air inlets;

the centrifugal impeller is arranged in the machine shell main body, and the air inlet ends of the centrifugal impeller are respectively communicated with the first air inlet through a collector;

the rotating shaft sequentially penetrates through the machine shell body, the current collector and the centrifugal impeller and is connected with a driving device;

and the airflow sequentially passes through the air inlet box, the first air inlet, the collector and the air inlet end of the centrifugal impeller and then is sequentially output from the radial air outlet end of the centrifugal impeller and the radial air outlet of the machine shell body.

9. The high-specific-speed energy-saving centrifugal dust removal fan according to claim 8, wherein the inlet of the air inlet box is rectangular, and the length-width ratio of the rectangle is 1: 4.

10. The high-specific-speed energy-saving centrifugal dust removal fan according to claim 8, wherein an adjusting door for adjusting the gas flow is arranged at the inlet of the air inlet box, and the adjusting door comprises a plurality of adjusting door blades.

11. The high specific speed energy-saving centrifugal dust removal fan according to claim 10, wherein the adjusting door blade is a shuttle-shaped hollow blade.

12. The high specific speed energy-saving centrifugal dust removal fan according to claim 10, wherein the number of the blades of the adjusting door and the number of the blades of the centrifugal impeller are prime numbers.

13. The high specific speed energy-saving centrifugal dust removing fan according to claim 12, wherein the number of the blades of each group of the blade assemblies is 12 or 16, and the number of the regulating gate blades provided for each multi-blade regulating gate is 5 or 7.