RU2330188C1 - Centrifugal fan (versions) - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: fan incorporates scroll case 1, impeller 2 with blades 8 and front disk 7, inlet manifold 4 with cylindrical section 16, inlet branch pipe 5 equal to width L of casing 1, annular gap 11 between the surfaces of manifold 4 and disk 7. Blades 8 are furnished with leading-edge flap 17 arranged between the abutment of blade 8 to the surface of front disk 7 and axis 13 of impeller 2. Here note that the straight line connecting axis 13 and tip 20 of leading-edge flap 17, in a plane projection perpendicular to axis 13, does not extend beyond a sector limited by rays located in the range of ± 0.05 of the blade angular pitch t relative to the straight line connecting axis 13 and point 21 of the abutment of front leading-edge 18, the next along the rotation of blade 8A, to the surface of front disk 7. In compliance with the first version, plate 12 of vortex arrester, its height making h_Va=H_Va=10...0.12, is arranged on outer surface 9 of manifold 4 between the meridian planes crossing the line of complete opening of casing 1 and shifting by 45° from the aforesaid plane towards cut-off sheet 14. In compliance with the second version, plate 24, its height making h_pS=H_pS/D=10...0.14, is connected to casing 1 opposite to blades 8 between the meridian planes crossing the line of maximum opening of casing 1 and tip 25 of cut-off sheet 14.

EFFECT: higher pressure characteristic and efficiency in the operating area with lower noise at the fan inlet at the blade frequency and its harmonics.

9 cl, 19 dwg

Description

The group of inventions relates to radial fans in a spiral case.

The prior art radial fans with eddies at the entrance to the impeller.

In the description of the invention, “Centrifugal Fan”, protected by RF patent No. 2215195, IPC F04D 17/08, priority 04/27/2002, publication date 10/27/2003, [1], there is a radial fan containing a spiral casing installed in it on the shaft there is an impeller with backward-curved blades and with a conical cover disk, an inlet manifold with sections of a curved profile in a meridional section, the outer surface of which forms a circumferential gap with the inner surface of the cover disk at the entrance to the impeller, a vortex suppressor made in de at least one plate placed on the outside of the inlet manifold in front of the circumferential gap in the zone of greatest opening of the casing, the outlet pipe is equal in width to the casing of the fan, and the width of the casing L is 0.9 ... 1.1 of the diameter D of the working wheels, the input manifold contains a cylindrical section, the length of the input manifold L _BX is 0.48 ... 0.63 of the diameter D of the impeller, and the diameter of the input D _{BX of the} impeller is 0.66 ... 0.69 of the diameter D of the impeller .

In the description of the utility model “Radial fan”, protected by RF patent No. 54112, IPC F04D 17/08, priority December 27, 2005, publication date 06/10/2006, [2], a radial fan is provided containing a spiral casing equipped with a tongue an impeller installed in the housing on the shaft with backward-curved blades and with a conical cover disc, an inlet manifold with sections of a curved profile in diametric section, the outer surface of which forms a circumferential clearance at the inlet of the impeller at the inlet of the outlet a nozzle whose width is equal to the width of the spiral case, a vortex suppressor made in the form of at least one plate placed on the outside of the suction nozzle in front of the circumferential clearance between the planes passing through the axis of rotation of the impeller, one of which intersects the line of greatest opening of the case, and the other is located at an angle of 45 degrees in the direction of the tongue of the spiral casing.

Placing the vortex suppressor plate in the invention [1] and in the utility model [2] in the zone of the greatest distance of the impeller from the spiral section of the housing provides high aerodynamic characteristics of the fan, however, studies have shown the possibility of reducing the acoustic noise of the fan at the inlet.

The radial fan presented in the description of the utility model [2] is taken as the closest analogue of the variants of the invention.

Solved technical problem is to increase the efficiency of the fan. The technical result consists in increasing the pressure characteristics and efficiency of the fan in the working area while reducing the sound power at the fan inlet at the blade frequency and its harmonics.

Disclosure of embodiments of the invention.

The radial fan according to the 1st embodiment, as in the closest analogue [2], contains a spiral casing equipped with a tongue, an impeller mounted on the shaft on the shaft with backward curved blades and with a conical cover disc, an inlet manifold with sections of a curved profile in the diametrical cross-section, the outer surface of which forms with the inner surface of the cover disk at the entrance to the impeller a circumferential gap, an outlet pipe, a vortex suppressor made in the form of at least one plate placed with the outer the suction pipe in front of the circumferential gap between the planes passing through the axis of rotation of the impeller, one of which crosses the line of maximum opening of the housing, and the other is located at an angle of 45 degrees to the side of the tongue of the spiral housing, but in contrast to the closest analogue [2], the height of the specified plate the vortex suppressor is 0.10 ... 0.12 of the diameter of the impeller, and each blade of the radial impeller is made with a slat located between the blade contacting the surface of the front disk and the axis of rotation the impeller, while projecting onto a plane perpendicular to the axis of rotation of the impeller, the straight line connecting the axis of rotation of the impeller and the slat nose does not go beyond the sector limited by beams located in the range of ± 0.05 of the angular pitch of the blades relative to the straight line connecting the axis the rotation of the impeller and the abutment point of the leading edge of the blade following the rotation of the blade to the surface of the front disk.

The radial fan according to the 1st embodiment is characterized in that the width of the outlet pipe is equal to the width of the spiral casing, which is 0.9 ... 1.1 of the diameter of the impeller, the inlet manifold contains a cylindrical section, the length of the inlet manifold is 0.48 ... 0 , 63 of the diameter of the impeller, and the diameter of the entrance to the impeller is 0.66 ... 0.69 of the diameter of the impeller.

At least one eddy absorber plate in a diametric section is located at an angle of ± 10 degrees to the input manifold, counting from the meridional direction towards the direction of rotation of the impeller and at an angle of ± 10 degrees to a plane passing through the axis of rotation of the impeller.

The radial fan according to the 2nd embodiment, as in the closest analogue [2], contains a spiral casing equipped with a tongue, an impeller installed in the casing on the shaft with backward curved blades and with a conical cover disc, an inlet manifold with sections of a curved profile in diameter cross-section, the outer surface of which forms with the inner surface of the cover disk at the entrance to the impeller a circumferential gap, an outlet pipe, a vortex suppressor made in the form of at least one plate placed with the outer the suction pipe in front of the circumferential gap between the planes passing through the axis of rotation of the impeller, one of which crosses the line of maximum opening of the housing, and the other is located at an angle of 45 degrees to the side of the tongue of the spiral housing, but unlike the closest analogue [2], the radial fan is equipped a plate mounted on the wall of the spiral casing opposite the impeller vanes between two meridional planes intersecting, respectively, the line of greatest opening of the spiral casing the tongue toe of the spiral casing, in the tapering part of the spiral casing adjacent to the line of maximum opening of the casing, and each blade of the radial impeller is made with a slat located between the contact of the blade to the surface of the front disk and the axis of rotation of the impeller, while projecting onto a plane perpendicular the axis of rotation of the impeller, the straight line connecting the axis of rotation of the impeller and the slat toe does not extend beyond the sector limited by beams located in the range of ± 0.05 of the angular pitch of the blade the current is relatively direct, connecting the axis of rotation of the impeller and the abutment point of the leading edge of the blade following the rotation of the blade to the surface of the front disk.

The radial fan according to the 2nd embodiment is characterized in that the plate on the wall of the spiral casing is installed at an angle of 70 ± 5 degrees to the axis of rotation of the impeller, and the height of the plate is 0.10 ... 0.14 of the diameter of the impeller.

The radial fan according to the 2nd embodiment is characterized in that the vortex suppressor plate is located between the passing meridional planes, one of which crosses the line of greatest opening of the casing, and the other is located at an angle of 45 degrees to the tongue of the spiral casing, while the height of the vortex suppressor plate is 0.10 ... 0.12 impeller diameters.

The radial fan according to the 2nd embodiment is characterized in that the width of the outlet pipe is equal to the width of the spiral casing, comprising 0.9 ... 1.1 of the diameter of the impeller, the inlet manifold contains a cylindrical section, the length of the inlet manifold is 0.48 ... 0 , 63 of the diameter of the impeller, and the diameter of the entrance to the impeller is 0.66 ... 0.69 of the diameter of the impeller.

At the same time, at least one vortex suppressor plate in the meridional section is located at an angle of ± 10 degrees to the input manifold with a count from the radial direction towards the direction of rotation of the impeller and at an angle of ± 10 degrees to a plane passing through the axis of rotation of the impeller.

The group of inventions is illustrated by drawings.

Figure 1 shows the fan when viewed from above.

Figure 2 shows a section aa in figure 1.

Figure 3 shows a section bB in figure 2.

Figure 4 shows the remote element In figure 3.

Figure 5 shows a view of D in figure 4.

Figure 6 is a section GG in figure 1.

7 shows a view of E in figure 4.

On Fig shows a fragment of the impeller with the location of the blades in the zone of permissible deviations from the angular pitch.

Figure 9 shows the impeller blade in side view.

In Fig.10 shows a view of G in Fig.9 when performing the blades from a solid sheet.

In Fig.11 shows a view of G in Fig.9 when performing the composite blades.

In Fig.12 shows the remote element And in Fig.2.

On Fig presents a graph of the dependence of the coefficient of total pressure of the fan from the height of the plate of the vortex suppressor.

On Fig presents a graph of the dependence of the efficiency of the fan on the height of the plate of the vortex suppressor.

On Fig presents a graph of the dependence of the coefficient of total pressure of the fan on the height of the plate in a spiral casing.

On Fig presents a graph of the dependence of the efficiency of the fan on the height of the plate in a spiral casing.

On Fig presents a comparison of the narrow-band spectrum of noise at the suction of the claimed and accepted for the closest analogue of radial fans.

On Fig presents a comparison of the sound power level at the input of the claimed fan and fan - the closest analogue.

On Fig shows the influence of the relative angular deviation of the slat on the difference in sound pressure ΔL at the blade frequency of the claimed fan and fan - the closest analogue.

Variants of the radial fan are arranged as follows.

The radial fan in both versions contains a spiral casing 1 (Fig. 1, 2, 3), an impeller 2 installed in it, the shaft 3 of which is kinematically connected with an electric drive, for example, with an electric motor (Fig. 3), an input manifold 4 with a curved profile in diametrical section and outlet pipe 5 (Fig.1, 2, 3). The impeller 2 includes a main 6 and a front 7 discs and blades 8 installed between them. Between the outer surface 9 of the inlet manifold 4 (FIG. 4), the front disc 7 and the walls of the housing 1, a circulation chamber 10 is formed (FIG. 3).

At the entrance to the impeller 2 between the inner surface of the front disc 7 and the outer surface 9 of the input manifold 4, an annular gap 11 is formed (Figs. 4, 5). A circumference on the outside of the input manifold 4 is a vortex suppressor made in the form of at least one plate 12. Moreover, one of the vortex suppressor plates 12 is mounted in the sector between the conventional meridional planes (i.e., planes passing through the axis of rotation 13 of the working wheels 2), one of the planes (Pl. A, Fig. 6) crosses the line of greatest opening of the spiral casing 1, and the other (Pl. B, Fig. 6) is located at an angle of 45 degrees towards the tongue 14 of the spiral casing 1 (in the system coordinates in Fig.6, δ = 0 ...- 45 °). The inner edge of the plate 12 of the vortex damper is connected to the surface of the inlet manifold 4 (4, 7).

In both versions of the radial fan, each blade 8 of the impeller 2 contains a main section 15, the front edge 16 (figure 2, 8, 9) of which is adjacent to the front disk 7, and a section located closer to the axis of rotation of the impeller 13, hereinafter referred to as " slat "17 (Fig.2, 3, 8, 9). The main section 15 and the slat 17 can be made as a whole, for example, from a sheet of metal (Fig. 9, 10) or in the form of an aerodynamic profile (not shown in Fig.), Or composite (Fig. 11) by attaching a slat 17 to the main part 15 of the blade 8. The leading edge 18 of the slat 17 can be located in the range of angles ± 10 degrees to the plane perpendicular to the axis of rotation 13 of the impeller 2, and the lateral edge 19 is at an acute angle to the leading edge 18 (FIGS. 3, 9) , and are interconnected by a smooth curve, for example, with an arc of a circle, forming a forefoot toe 20 Single 17 (Figure 9). The leading edge 18 of the slat 17 is made curved, for example, along an arc of a circle in projection onto a plane perpendicular to the axis of rotation 13 of the impeller 2 (FIGS. 3, 9), and its side edge 19 can be curved, for example, increasing with increasing distance from leading edge 16 local radius R _BC (Fig.9). The surface of the slat 17 can be made in the form of a surface with smooth contours, in particular a cylindrical one (Fig. 8), or with a steep slat 17 and the main section 15 of the blade 8 (not shown in Fig.). In the projection onto a plane perpendicular to the axis of rotation of the impeller 13, the straight line connecting the axis of rotation of the impeller 13 and the nose 20 of the slat 17 does not extend beyond the sector limited by the rays located in the range Δt = ± 0.05 of the angular pitch t of the blades 8 relative to the straight line connecting the rotational axis 13 of the impeller 2 and the abutment point 21 of the leading edge 16 of the next blade 8A along the rotation of rotation with the front disc 7 (Fig. 8). In this case, the point on the toe 20 through which the straight line passes is determined when the slat 17 is tangent to the toe 20 and is parallel to the axis 13 of the impeller 2, and the angular pitch t is 2πrad divided by the number of blades N in the impeller: t = 2π / N.

The main section 15 of the blade 8 can be performed both with a curved, for example a cylindrical, surface, and with a flat surface. When making the main section 15 of the blades 8 flat, its front edge 16 can be made straightforward (Figs. 3, 9). In this case, the front disk 7 at the abutment section of the blade 8 (Fig.3, 9) is a hyperbolic surface, the generatrix of which is the rectilinear front edge 16 of the main section 15 of the blade 8.

To ensure the rigidity of the slats 17 of the blades 8, if necessary, the lateral edges 18 of the slat 17 are connected by a ring 22 (figure 3). Similar rings can be installed on the output edges 23 of the blades 8 (Fig. 3) in addition to the already installed ring 22 on the lateral edges 18 of the slat 17 (not shown in Fig.).

In accordance with the first embodiment of the radial fan, the relative height h _{B of the} vortex suppressor plate 12, equal to the ratio of the height H _{B of the} vortex suppressor plate 12 to the diameter D of the impeller 2 (equal to the diameter of the circle described by the ends of the blades 8), is: h _B = Н _B /D=0.10...0.12. The swirl plate 12 in diametric section can be installed at an angle α = 0 ± 10 degrees to the input manifold 4 with a count towards the direction of rotation of the impeller 2 (Fig. 5) and at an angle β = ± 10 degrees. relative to the axis of rotation 13 of the impeller 2 (Fig.7), and the outer edge of the plate 12 can be performed as rectilinear (Fig.4), and curvilinear (Fig. not shown).

In accordance with the 2nd embodiment, the radial fan is equipped with a plate 24 mounted on the wall of the spiral casing 1 opposite the blades 8 of the impeller 2 in the tapering part of the spiral casing 1 adjacent to the line of maximum opening of the casing, between the conditional meridional planes, one of which passes through the toe 25 of the tongue 14 of the spiral casing 1 (Pl. B, Fig. 2), and the other (Pl. A, Fig. 2) crosses the line of greatest opening of the spiral casing 1 (Figs. 1, 3). In this case, the relative height h _{SP of the} plate 24, equal to the ratio of the height H _{SP of the} plate 24 to the diameter D of the impeller 2 (Fig. 12), is: h _SP = H _{SP /} D = 0.10...0.14. The plate 24 is installed at an acute angle γ _SP to the axis 13 of rotation of the impeller 2 (figure 1) and can be performed with a rectilinear or arbitrary shape of the outer and side edges, with a flat or complex surface. With a variable width of the plate 24 (for example, with a rectilinear outer edge), the height H _SP is taken in its middle part (Fig. 12). The length of the plate 24 can vary within wide limits, however, as a rule, does not exceed the width H of the blades 8 of the impeller 2 (figure 3).

The preferred embodiment of the radial fan options.

In a preferred embodiment, the radial fan according to the first embodiment contains one flat plate 12 of the vortex suppressor with a height H _B = 0.10 ... 0.12 of the diameter D of the impeller 2, the plate 12 is in contact with the outer surface 9 of the input manifold 4 and is installed at angles α _B = 0 ° and β _B = 0 ° (Fig. 5,7), the input manifold 4 is made with a cylindrical insert 26, the length L _{BX of the} input manifold 4 is 0.48 ... 0.63 of the diameter D of the impeller 2, the diameter D _{BX of the} suction pipe 4 at the entrance to the impeller 2 is 0.66 ... 0.69 the diameter D of the impeller 2, the width H of the blades 8 the impeller 2 is equal to at least 0.25 ... 0.3 7 of the diameter D of the impeller 2, the width of the outlet pipe 5 is equal to the width L of the spiral casing 1 of the fan and is 0.9 ... 1.1 of the diameter D of the impeller 2: L _BX = (0.48 ... 0.63) V; D _BX = (0.66 ... 0.69) D; H≥0.35D; L = (0.9 ... 1.1) D, H _B = (0.10 ... 0.12 D) (Figs. 1, 3). The plate 24 is installed in such a way that it intersects the plane formed by the circumference of the maximum diameter of the front disk 7.

In a preferred embodiment of the fan according to the 2nd embodiment, a plate 24 is additionally installed at an angle γ _SP = 70 ± 10 degrees to the axis of rotation of the impeller 2 (Fig. 1) and is located closer to the meridional plane of Pl.V passing through the nose 25 of the tongue 14 spiral housing 1 (figure 2), and the height of the plate 25 is H _SP = (0.10 ... 0.14) D.

In this case, the impeller 2 in the fans according to both embodiments (FIGS. 2, 3) contains 13 blades 8, the width H of the blades 8, equal to the distance between the front 7 and the main 6 disks at the outlet of the impeller 2, is 0.25 .. .0.37 of the diameter of the impeller D. The main section 15 of the blades 3 is made flat, and the adjacent slat 17 in cross section perpendicular to the axis of rotation 13 of the impeller 2, in the form of an arc of a circle, the front 18 and lateral 19 edges of the slat 17 are connected in a circle and the side edge 19 is provided with a local radius R _TC equal to not m 0,5D it near the leading edge 18 and parallel to the axis of rotation of the impeller 13 February (ie equal to infinity) near the primary drive 6 (Figure 9). In a projection onto a plane perpendicular to the axis of rotation of the impeller 2, the straight line connecting the axis of rotation of the impeller 2 and the nose 20 of the slat 17 does not extend beyond the sector limited by beams located in the range Δt = ± 0.05t relative to the straight line connecting the axis 13 of the rotation of the impeller 2 and the abutment point 21 of the leading edge 18 of the blade 8A following along the rotation of rotation with the front disc 7 (Fig. 8). In this case, the front 7 and main 6 discs can be performed with an increased diameter equal to (1.1 ... 1.2) D and (1.05 ... 1.15) D, respectively, with the formation in the meridional section between the generatrices of the front 7 and the main 6 disks in the direction from the axis of rotation 13 to the output edges 23 of the blades 8 of the impeller 2 of the non-expanding channel (not shown in Fig.).

Radial fan operates as follows.

When the impeller 2 rotates in the circulation chamber 10, a swirling toroidal (vortex) flow occurs. The installation of a vortex suppressor containing at least one plate 12 in the area of exit from the spiral housing provides braking of the toroidal (vortex) flow, which is accompanied by an increase in pressure in the circulation chamber 10 in front of the annular gap 11 (Figs. 3, 5). As a result of the pressure difference in the circulation chamber 10 and at the entrance to the impeller 2, an annular jet is blown onto the inner surface of the cover disk 7 through the annular gap 11, which increases the momentum of the jet formed in the annular gap 11. This creates an additional rarefaction on the inner surface of the cover disk 7 , reducing the intensity of the vortex and, therefore, reducing aerodynamic losses not only at the entrance to the impeller 2, but also the fan as a whole.

Dependence of the total pressure coefficient ψ = 2P _V / ρu ² and the efficiency η _B (efficiency) of the fan according to the first embodiment on the relative height h _{B of the} eddy suppressor plate 12 at constant values of the performance coefficient φ = 4Q / πD ² u (where Q - fan performance, P _V is the total pressure, D is the diameter of the impeller 2 of the fan, u is the peripheral speed of the ends of the blades 8 of the impeller 2 of the fan, ρ is the air density) and at the optimum installation location of the plate 12 of the vortex suppressor obtained in the experiments, as shown in Fig.13 and 1 4, affects the total pressure ψ and the efficiency η _{B of the} fan, with the achievement of a pronounced maximum in the range h _B = 0.10 ... 0.12. This, most likely, is associated with the braking of the air involved in the movement during the rotation of the front disk 7, and arising behind the plate 12 of the stagnant zone. At a low height h _{In the} plate 12, sufficient inhibition of the circulation flow is not provided, which reduces the momentum of the jet formed in the circumferential gap 11. At a high height of the plate 12, a braking zone appears in front of it in the region of the maximum opening of the spiral of the housing 1, as a result of which it is blown into the annular gap 11 a jet of air, which increases the momentum of the jet flowing to the surface of the front disk 7, and the height hB of the plate 12 has quite distinct values at which the maximum of the coefficients ψ and η _B is reached. A further increase in the height of the plate 12, apparently, violates the toroidal (vortex) flow, which leads to a deterioration in the aerodynamic characteristics of the radial fan. This confirms the significance of the feature relating to the selected boundaries of the height h _B = H _B / D of the vortex suppressor plate 12.

When performing plate 12 curved aerodynamic losses are less than when performing plate 12 flat. The installation angles α _B , β _{B of} the curved plate 12 and the channel profile in the circumferential gap 11 should be optimized depending on the parameters and operating conditions of the fan. However, the interface plate 12 with the outer surface 9 of the inlet manifold 4 has a complex spatial contour, which complicates the manufacturing technology of a centrifugal fan.

The implementation of the plate 12 flat with an inner edge in contact with the outer surface 9 of the inlet manifold 4, and the location of the plate 12 along the generatrix in the diametrical section of the inlet manifold 4 at an angle α = ± 10 ° in the direction of rotation of the impeller 2 provides manufacturability of the eddy current suppressor and the fan as a whole . The placement of the plate 12 at an angle β = ± 10 ° is due to a decrease in the accuracy of the connection of the plate 12 with the outer surface 9 of the input manifold 4 and has little effect on the technical result.

For the fan, made according to the 2nd embodiment, the coefficients of the total pressure ψ and efficiency η _B , when the relative height h _SP = H _SP / D of the plate 24 also changes, has a maximum (Figs. 15 and 16). The presence of the plate 24 contributes to a more uniform distribution of the velocity field in the outlet pipe 5 by directing a portion of the flow towards the wall of the spiral casing 1. When the plate 24 is located closer to the outlet pipe 5 from the meridional plane of pl. A, a sufficient uniformity of the velocity field is not achieved, as with the location plate 23 towards the narrowing of the spiral casing 1 from the meridional plane of Pl.V.

The implementation of the fan in both versions of the input manifold 4 of length L _BX = (0.48 ... 0.63) D due to the cylindrical section 26 with the diameter of the entrance to the impeller 2 equal to D _BX = (0.66 ... 0, 69) D provides increased uniformity of the flow entering the impeller 2, which delays the separation of the boundary layer from the surface of the front disk 7 and from the blades 8 of the impeller 2 during its rotation. As a result, it is possible to increase the width H of the blades 8 to 0.35 and above the diameter D of the impeller 2: H≥0.35D. This makes it possible to increase the width L of the casing to L = (0.9 ... 1.1) D, as a result of which the static pressure of the exhaust stream of the fan increases in both the 1st and the 2nd embodiment. The implementation of the outlet pipe 5 and the spiral housing 1 of the same width L simplifies the manufacturing technology of the fan.

The claimed variants of the radial fan (indicated by a light tone) have, as shown in Fig. 17, lower sound pressure values at the blade frequency and its harmonics as compared to the fan adopted as the closest analogue [2] (indicated by a dark tone). As a result, the sound power levels at the input of the claimed radial fan options (indicated by a light tone), as shown in FIG. 18, are reduced compared to the sound power levels of a fan adopted as the closest analogue [2] (indicated by a dark tone). Moreover, it was experimentally established that with a relative deviation Δt of the position of the toe 20 of the slat 17 of the blade 8 of the impeller 2 from the angular step t, the difference in sound pressure is ΔL _B at the blade frequency of the claimed fan L (f) _B and the fan is the closest analogue [2], L _BA , - reaches, as shown in Fig. 19, the maximum values modulo.

The options for radial fans in a spiral case presented in the description can be manufactured at any specialized enterprise. The implementation of the invention ensures the achievement of the claimed technical result, namely, it reduces the sound power at the fan inlet at the blade frequency and its harmonics at high aerodynamic characteristics. The parameters of the vortex suppressor, made in the form of a plate 12, the size of the circumferential gap 11, as well as the parameters and installation location of the plate 24 in the spiral casing 1 can be optimized in the indicated angle ranges depending on the operating conditions and characteristics of the fan.

The list of positions and symbols for the description of the group of inventions "Radial fan (options)"

1 - spiral case;

2 - impeller;

3 - shaft drive, for example an electric motor;

4 - input collector;

5 - output pipe;

6 - the main disk;

7 - cover disk;

8 - blades of the impeller 2;

9 - the outer surface of the inlet manifold 6;

10 - circulation chamber;

11 - circumferential clearance;

12 - vortex suppressor plate mounted on the outer surface 9 of the inlet manifold 4 in the zone of greatest opening of the housing 1;

13 - axis of rotation of the impeller 2;

14 - the language of the spiral casing 1;

15 - the main section of the blade 8,

16 - the front edge of the main section 15 of the blades 8, adjacent to the front disk 7;

17 - slat - a section located closer to the axis 13 of rotation of the impeller 2;

18 - the leading edge of the slat 17;

19 - lateral edge of the slat 17;

20 - toe slat 17;

21 - the abutment point of the leading edge 18 of the next along the rotation of the blade 8A with the front disk 7;

22 - a ring connecting the side edges 19 of the slats 17 of the blades 8;

23 - the output edge of the blades 8 of the impeller 2;

24 - a plate mounted on a spiral casing 1 in the zone of its greatest opening;

25 - the toe of the tongue 14 of the spiral housing 1;

26 is a cylindrical section of the inlet manifold 4.

Pl.A - meridional plane passing through the axis of rotation 13 of the impeller 2 and crossing the line of greatest disclosure of the spiral housing 1;

Pl. B - meridional plane passing through the axis of rotation 13 of the impeller 2 and located at an angle of 45 degrees to the meridional plane of Pl. A in the direction of the tongue 14 of the spiral housing 1;

Pl.V - meridional plane passing through the axis of rotation 13 of the impeller 2 and the toe 25 of the tongue 14 of the spiral housing 1;

δ _{In the} angle of installation of the plate 12 of the vortex suppressor;

α _In - the angle of inclination of the plate 12 of the vortex suppressor to the suction pipe 6 with a countdown towards the direction of rotation of the impeller 2;

β _B - the angle of inclination of the plate 12 of the vortex damper to the axis 13 of rotation of the impeller 2;

γ _SP - the angle of inclination of the plate 16 to the axis of rotation 13 of the impeller 2;

L _BX - input manifold length 4;

D is the diameter of the impeller 2;

D _BX - diameter of the inlet manifold 4 at the entrance to the impeller 2;

H - the width of the impeller 2;

L is the width of the housing 1 of the fan;

N _B - the height of the plate 12 of the vortex suppressor;

N _SP - the height of the plate 24 mounted on the wall of the spiral housing 1;

h _B = H _B / D is the relative height of the vortex suppressor plate 12;

h _SP = N _SP / D is the relative height of the plate 24 mounted on the wall of the spiral casing 1;

η _B - fan efficiency (Efficiency);

ψ = 2Р _V / ρu ² - coefficient of total pressure of the fan;

ψ = 4Q / πD ² u - fan performance coefficient;

Q - fan performance;

P _V is the total pressure of the fan;

u is the peripheral speed of the ends of the 23 blades 8 of the impeller 2 of the fan;

ρ is the air density;

t = 2π / N is the angular pitch of the blades 8 of the impeller 2, equal to 2π rad, divided by the number of blades N in the impeller;

Δt is the angle between the straight lines in the projection onto the plane perpendicular to the axis of rotation of the impeller 2, connecting the axis 13 of rotation of the impeller 2 with the point 21 of the abutment of the blades 8 of the impeller 2 to the surface of the front disc 7, and connecting the axis of rotation of the impeller 2 with the toe 20 slat 17;

ΔL = L (f) _B -L _BA is the difference in sound pressure at the blade frequency at the inlet of the declared fan L (f) _B and the fan - the closest analogue [2] L _BA .

Claims (9)

1. A radial fan containing a spiral casing, equipped with a tongue, an impeller mounted on the shaft of the impeller with backward curved blades and with a conical cover disc, an inlet manifold with sections of a curved profile in a diametrical section, the outer surface of which forms with the inner surface of the cover disc at the input in the impeller there is a circumferential gap, an outlet pipe, the width of which is equal to the width of the spiral case, a vortex suppressor made in the form of at least one plate placed with an external the crowns of the suction pipe in front of the circumferential gap between the planes passing through the axis of rotation of the impeller, one of which crosses the line of maximum opening of the housing, and the other is located at an angle of 45 ° to the side of the tongue of the spiral housing, characterized in that the height of the specified plate vortex suppressor is 0.10. ..0,12 of the diameter of the impeller, and each blade of the radial impeller is made with a slat located between the abutment of the blade to the surface of the front disk and the axis of rotation of the impeller, when ohm in the projection onto a plane perpendicular to the axis of rotation of the impeller, the straight line connecting the axis of rotation of the impeller and the slat nose does not go beyond the sector limited by beams located in the range of ± 0.05 of the angular pitch of the blades relative to the straight line connecting the axis of rotation of the impeller and point of contact of the leading edge of the blade following the rotation of the blade to the surface of the front disk. 2. The radial fan according to claim 1, characterized in that the width of the outlet pipe is equal to the width of the spiral casing, comprising 0.9 ... 1.1 of the diameter of the impeller, the inlet manifold contains a cylindrical section, the length of the inlet manifold is 0.48 .. .0.63 of the diameter of the impeller, and the diameter of the entrance to the impeller is 0.66 ... 0.69 of the diameter of the impeller. 3. The radial fan according to claim 1 or 2, characterized in that at least one vortex suppressor plate in the meridional section is located at an angle of ± 10 ° to the inlet manifold, counting from the radial direction towards the direction of rotation of the impeller, and at an angle of ± 10 ° to the plane passing through the axis of rotation of the impeller. 4. A radial fan containing a spiral casing, equipped with a tongue, an impeller mounted on the shaft on the shaft with backward curved blades and with a conical cover disc, an inlet manifold with sections of a curved profile in a diametrical section, the outer surface of which forms with the inner surface of the cover disc at the input in the impeller there is a circumferential gap, an outlet pipe, the width of which is equal to the width of the spiral case, a vortex suppressor made in the form of at least one plate placed with an external torons of the suction pipe in front of the circumferential gap between the planes passing through the axis of rotation of the impeller, one of which crosses the line of maximum opening of the housing, and the other is located at an angle of 45 ° to the tongue of the spiral housing, characterized in that the radial fan is equipped with a plate mounted on the wall of the spiral the case opposite the impeller vanes between two meridional planes intersecting, respectively, the line of greatest opening of the spiral housing and the tongue toe th body in the tapering part of the spiral casing adjacent to the line of maximum opening of the casing, while the height of the plate is 0.10 ... 0.14 of the diameter of the impeller, and each blade of the radial impeller is made with a slat located between the blade adjacent to the front surface the disk and the axis of rotation of the impeller, while in a projection onto a plane perpendicular to the axis of rotation of the impeller, the straight line connecting the axis of rotation of the impeller and the slat nose does not extend beyond the sector limited by the rays laid in the range of ± 0.05 of the angular pitch of the blades relative to the straight line connecting the axis of rotation of the impeller and the abutment point of the leading edge of the blade following the rotation of the blade to the surface of the front disk. 5. The radial fan according to claim 4, characterized in that the plate on the wall of the spiral casing is installed at an angle of 70 ± 10 ° to the axis of rotation of the impeller. 6. The radial fan according to claim 4 or 5, characterized in that at least one plate mounted in a spiral casing is made flat. 7. The radial fan according to claim 4, characterized in that the height of the vortex suppressor plate is 0.10 ... 0.12 of the diameter of the impeller. 8. The radial fan according to claim 4, 5, or 7, characterized in that the width of the outlet pipe is equal to the width of the spiral casing, comprising 0.9 ... 1.1 of the diameter of the impeller, the inlet manifold contains a cylindrical section, the length of the inlet manifold is 0.48 ... 0.63 of the diameter of the impeller, and the diameter of the entrance to the impeller is 0.66 ... 0.69 of the diameter of the impeller. 9. The radial fan according to claim 7, characterized in that at least one vortex suppressor plate in the meridional section is located at an angle of ± 10 ° to the inlet manifold, counting from the radial direction towards the direction of rotation of the impeller, and at an angle of ± 10 ° to a plane passing through the axis of rotation of the impeller.

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