EP2206929A1 - Fan unit with a free radial fan impeller - Google Patents

Abstract

Summary The invention relates to impeller assemblies having free radial impellers primarily for use in duct blowers. The technical result consists in the increase of the output power combined with an increase of the static pressure and a reduction of the noise level. The impeller assembly includes a radial impeller having a front windshield and a main pulley with vanes disposed between vanes and inclined rearwardly, an input collector having a convergent input portion and an output portion, and an auxiliary portion defining an area between an input portion and an output portion having a small curvature and a length (L u, k) which is not less than 0.04 of the diameter (D) of the impeller. The front windshield and the output section of the input collector together form an annular gap, in front of which plates of a vortex extinguisher are arranged. In the projection of the plane perpendicular to the axis of rotation of the impeller, the straight line connecting the axis of rotation with a cam of the slat does not exceed the limits of ± 0.05 of the angular step (t) from blade to blade with respect to the straight line; which connects the axis of rotation with the joint of that blade, which follows in the direction of rotation of the front windshield.

Description

Blower with a free radial impeller

The invention relates to a fan with a free radial fan wheel, which is provided in the field of fan design, mainly for use in low-noise duct fans.

As prior art blower assemblies with free radial impellers are known, which are mainly intended for use in duct blowers.

In the catalog "Centrifugal fans with asynchronous external rotor motor", 11.2004, Ziehl-Abegg, pages 9/1 to 9/23, [1], an impeller assembly with a free radial fan impeller of the RH ... G-type is disclosed, wherein this arrangement comprises a radial impeller and an input collector and the impeller has a main disk and a front windshield. There are blades between these discs arranged, which are inclined with respect to the direction of rotation to the rear. The input collector has a convergent input section and an output section. Its edge is disposed between the main disc and the input edge of the front windshield of the impeller and forms an annular recess.

The aerodynamic and acoustic tests performed on the fan wheel assembly with the fan wheel RH31G-4DK.0F / 1R (assembled with an electric motor and a collector) whose pressure and sound characteristics are listed on page 9/7 of the catalog [1], show that it was possible to substantially improve the pressure characteristics of the impeller assembly with the impeller of the type mentioned in the part of the output power increase. In this case, the static pressure generated by the impeller was increased by a change of the input collector and the blades of the impeller. In addition to improving the printing properties, the noise level at the inlet of the blower duct decreased with this fan wheel arrangement.

In the specification of the patent RF 2287091 , IPC F04D29 / 42, publication date 10.11.2006, [2], a duct fan is claimed, which is equipped with an impeller assembly having a free radial impeller consisting of a main disk, a cover disk and blades, which inclined backwards and are arranged between these discs. A symmetrical input collector is provided with a curvilinear profile in the meridian section forming a gap which converges the radial impeller inwardly between the surfaces of the cover disc and the input collector (convergent). A vortex extinguisher may be configured to have at least one plate connected to the wall of the input collector.

In the invention [2], it is shown that the presence of a vortex extinguisher increases the coefficient of static pressure. But there is no information about that Effect of the shape of the input collector on the pressure characteristics of the channel blower with such a fan wheel assembly.

The impeller assembly shown in Catalog [1] is considered by the present invention to be the closest analog.

The technical problem to be solved by the invention is to improve the aerodynamic properties associated with a reduction in the noise level of the impeller and thus the duct fan.

The technical result is an increase in output power associated with an increase in the static pressure of the impeller assembly.

The technical result is also a decrease in the noise level at the inlet of the duct fan equipped with the fan wheel assembly according to the invention.

The stated technical problem is solved by carrying out the invention with the following feature set, which is important for achieving the claimed technical results.

The impeller assembly having a free impeller as in the closest analog [1] has a radial impeller and an input collector. The radial impeller comprises a main disk and a front windshield with blades disposed between these disks and inclined rearwardly with respect to the axis of rotation. The input collector, the edge of which is disposed between the main disk and the input edge of the front windshield of the fan wheel to form an annular gap, has a convergent input portion and an output portion. In contrast to the closest analog [1] is the input collector with an additional section provided between the input portion and the output portion with an area which is connected to the surfaces of the input portion and the output portion of the input collector and having a generatrix of low curvature. In this case, the length of the additional portion is not less than 0.04 of the diameter of a circle circumscribed by the ends of the blades of the impeller. In front of the annular gap, a vortex extinguisher is arranged.

The impeller assembly with a free radial impeller is characterized by an additional portion provided with a cylindrical inner surface.

The impeller assembly having a free radial impeller is characterized by a vortex extinguisher formed by at least one plate connected to the outer walls of the collector.

The impeller assembly having a free radial impeller is characterized by an annular gap in the meridian section that converges within the radial impeller.

The impeller assembly with a free radial impeller is characterized in that each impeller of the impeller is provided with a slat disposed between the joint of the impeller on the surface of the front windshield and the axis of rotation of the impeller. Incidentally, in the projection of the plane perpendicular to the rotation axis of the impeller, the straight line connecting the rotation axis with a cam of the slat does not exceed the portion bounded by rays within a range of ± 0.05 of the angular step of the blades with respect to the straight line connecting the axis of rotation of the impeller and the abutment point of the front edge of the blade, which follows in the direction of rotation of the surface of the front windshield.

The impeller assembly with a free radial impeller is characterized in that a side edge of the slat of the blade of the impeller is disposed at an acute angle to the front edge of the slat.

In this regard, the impeller assembly with a free radial impeller is characterized in that the front end edge of the vane of the impeller formed in the section is perpendicular to the axis of rotation of the impeller, along a circular arc.

In addition, the impeller assembly with a free radial impeller is characterized in that the diameter of the front windshield is 1.1 ... 1.2 and the diameter of the main pulley is 1.05 ... 1.15 the diameter of a circle passing through the ends the blades of the fan wheel is circumscribed. In this case, a non-diverging channel is formed in the meridian plane between the generatrices of the front windshield and the main disk in the direction from the axis of rotation to the ends of the blades of the impeller.

The impeller assembly having a free radial impeller is characterized in that the width of the impeller at the exit of the impeller is not less than 0.25 of the diameter of a circle circumscribed by the ends of the blades of the impeller.

The impeller assembly having a free radial impeller is characterized in that the impeller is provided with at least one ring interconnecting the side edges of the vanes of the vanes.

• Fig. 1 einen Längsschnitt durch eine Gebläseradanordnung, die das nächstkommende Analogon darstellt,
• Fig. 2 einen Schnitt längs der Linie A-A in Fig.1,
• Fig. 3 eine Vergrößerung der Einzelheit B in Fig. 1,
• Fig. 4 einen Längsschnitt der Gebläseradanordnung gemäß der Erfindung,
• Fig. 5 einen Längsschnitt der Gebläseradanordnung gemäß der Erfindung mit einem radialen Gebläserad, das eine vergrößerte Vorderfrontscheibe und eine vergrößerte Hauptscheibe aufweist,
• Fig. 6 eine Vergrößerung der in den Figuren 4 und 5 dargestellten Einzelheit C,
• Fig. 7 einen Schnitt längs der Linie D-D in Fig. 4,
• Fig. 8 eine Seitenansicht einer Schaufel,
• Fig. 9 eine Ansicht in Richtung E in Fig. 8,
• Fig. 10 eine Ansicht einer zusammengesetzten Schaufel in Richtung E in Fig. 8,
• Fig. 11 einen Schnitt längs der Linie F-F in Fig. 5 in der bevorzugten Ausführung der Gebläseradanordnung,
• Fig. 12 ein Fragment eines Gebläserads mit Schaufeln, die sich in einem Bereich mit zulässigen Abweichungen des Winkelschritts befinden,
• Fig. 13 die Druckkennlinie ψ _S =F(ϕ) eines Gebläses mit einer Gebläseradanordnung in verschiedenen Ausführungen,
• Fig. 14 die Druckkennlinie ψ _S =F(ϕ) eines Gebläses mit einer Gebläseradanordnung mit verschiedenen Längen eines Zusatzabschnitts des Kollektors,
• Fig. 15 das Diagramm ψ _S=F(L _u,k /D), worin ϕ=const im Fall der Verwendung einer Gebläseradanordnung ohne einen Wirbellöscher in einem Kanalgebläse ist,
• Fig. 16 das Diagramm ψ_S(C-D) =F(L/D), worin ϕ=const im Fall der Verwendung einer Gebläseradanordnung mit einem Wirbellöscher in einem Kanalgebläse ist,
• Fig. 17 das Diagramm Δ ψ _S = ψ _S(B-I)- ψ_S=F((L _u,k /D), worin ϕ=const ist,
• Fig. 18 das Diagramm L_P=F(f) eines Schmalbandspektrums von Pegeln des Geräuschdrucks am Eingang des Kanalgebläses mit einer Gebläseradanordnung, die das nächstkommende Analogon ist, und mit einer Gebläseradanordnung, die mit Vorflügeln und einem Wirbellöscher ausgerüstet ist,
• Fig. 19 das Diagramm L_W =F(f) des Oktavspektrums der Pegel der Geräuschleistung am Eingang des Kanalgebläses mit der Gebläseradanordnung des nächstkommenden Analogons und mit der Gebläseradanordnung, die mit Vorflügeln und einem Wirbellöschers ausgestattet ist,
• Fig. 20 das Diagramm L_P=F(f) des Schmalbandspektrums von Pegeln des Geräuschdrucks unter den Bedingungen der Maximalausgangsleistung am Eingang des Kanalgebläses mit der Gebläseradanordnung des nächstkommenden Analogons und mit der Gebläseradanordnung gemäß der bevorzugten Ausführung der Erfindung,
• Fig. 21 das Diagramm L_P=F(f) des Schmalbandspektrums von Pegeln des Geräuschdrucks unter den Bedingungen einer mittleren Ausgangsleistung am Eingang des Kanalgebläses mit der Gebläseradanordnung des nächstkommenden Analogons und mit der Gebläseradanordnung gemäß der bevorzugten Ausführung der Erfindung,
• Fig. 22 das Diagramm L_W=F(f) des Oktavspektrums der Pegel der Geräuschleistung unter den Bedingungen der Maximalausgangsleistung am Eingang des Kanalgebläses mit der Gebläseradanordnung des nächstkommenden Analogons und mit der Gebläseradanordnung gemäß der bevorzugten Ausführung der Erfindung,
• Fig. 23 das Diagramm L_W=F(f) des Oktavspektrums der Pegel der Geräuschleistung unter den Bedingungen einer mittleren Ausgangsleistung am Eingang des Kanalgebläses mit der Gebläseradanordnung des nächstkommenden Analogons und mit der Gebläseradanordnung gemäß der bevorzugten Ausführung der Erfindung.

The invention will now be explained in more detail with reference to embodiments of an impeller assembly with a free radial impeller. Show it:

• Fig. 1 a longitudinal section through an impeller assembly, which represents the closest analogue,
• Fig. 2 a section along the line AA in Fig.1 .
• Fig. 3 an enlargement of the detail B in Fig. 1 .
• Fig. 4 a longitudinal section of the impeller assembly according to the invention,
• Fig. 5 a longitudinal section of the impeller assembly according to the invention with a radial impeller having an enlarged front windshield and an enlarged main disc,
• Fig. 6 an enlargement of the FIGS. 4 and 5 shown detail C,
• Fig. 7 a section along the line DD in Fig. 4 .
• Fig. 8 a side view of a shovel,
• Fig. 9 a view towards E in Fig. 8 .
• Fig. 10 a view of a composite blade in the direction of E in Fig. 8 .
• Fig. 11 a section along the line FF in Fig. 5 in the preferred embodiment of the impeller assembly,
• Fig. 12 a fragment of an impeller with vanes located in an area with allowed deviations of the angular step,
• Fig. 13 the pressure characteristic ψ _S = F ( φ ) of a blower with an impeller arrangement in various designs,
• Fig. 14 the pressure characteristic ψ _S = F ( φ ) of a blower with an impeller arrangement with different lengths of an additional section of the collector,
• Fig. 15 the diagram ψ _S = F (L _{u , k} / D), where φ = const in the case of using an impeller assembly without a vortex extinguisher in a duct fan,
• Fig. 16 the diagram ψ _{S (CD)} = F (L / D), where φ = const in the case of using an impeller assembly with a vortex extinguisher in a duct fan,
• Fig. 17 the diagram Δ ψ _S = ψ _{S (BI)} - ψ _S = F ((L _{u , k} / D) , where φ = const ,
• Fig. 18 the graph L _P = F (f) of a narrowband spectrum of levels of noise pressure at the entrance of the duct fan with an impeller assembly which is the closest analog and with an impeller assembly equipped with slats and a vortex extinguisher,
• Fig. 19 the diagram L _W = F (f) of the octave spectrum, the noise power level at the inlet of the duct fan with the fan wheel assembly of the nearest analog, and with the impeller assembly equipped with slats and a vortex extinguisher,
• Fig. 20 the graph L _P = F (f) of the narrowband spectrum of levels of noise pressure under maximum output power conditions at the entrance of the duct fan with the closest analogue fan wheel assembly and with the fan wheel assembly according to the preferred embodiment of the invention;
• Fig. 21 the plot L _P = F (f) of the narrowband spectrum of levels of noise pressure under conditions of average output power at the entrance of the duct fan with the closest analogue fan wheel assembly and with the fan wheel assembly according to the preferred embodiment of the invention;
• Fig. 22 the octave spectrum diagram L _W = F (f) shows the noise power level under the maximum output power conditions at the inlet of the duct fan with the nearest analogue fan wheel assembly and with the fan wheel assembly according to the preferred embodiment of the invention;
• Fig. 23 the octave spectrum graph L _W = F (f) shows the noise power level under the conditions of average output power at the entrance of the duct fan with the closest analogue fan wheel assembly and with the fan wheel assembly according to the preferred embodiment of the invention.

An impeller assembly having a free radial impeller as in the closest analog and in the FIGS. 1 to 3 is shown, has a radial impeller 1 and an input collector 2, which are connected to each other by means of a carrier (not shown) or in a housing of a channel blower (not shown). The radial impeller 1 has a front windshield 3 and a main disk 4, wherein blades 5 are arranged between these disks.

The impeller 1 is equipped with means for connection to a power drive (not shown) which serves to rotate the radial impeller 1 about its axis 6.

The blades 5 are inclined rearwardly with respect to the direction of rotation of the radial impeller 1 ( Fig. 2 ). The inlet 7 of the air flow into the radial impeller 1 is arranged in the plane which passes through the input edge 8 of the front windshield 3 (FIG. Fig. 3 ) is formed. The outlet 9 of the air flow from the radial impeller 1 lies between the outer edges 10 and 11 of the front windshield 3 and the main disk 4 (FIG. Fig. 1 ). The input collector 2 comprises a convergent input section 12 and an output section 13.

The edge 12 of the output section 13 is, as in FIGS FIGS. 1 and 3 shown between the main disk 4 and the input edge 8 of the front windshield 3 of the radial impeller 1 to form an annular gap 15 (FIG. Fig. 3 ) arranged.

The claimed impeller assembly, in addition to the means used in the closest analog, has an additional portion 16 (FIG. FIGS. 4, 5 and 6 ) disposed between the convergent input section 12 and the output section 13. Its surface is connected to the surfaces of the input section and the output section of the input collector. The generatrix of the inner surface of the auxiliary portion 16 may be formed with a weak curve 1 / R _{u , k} → 0 _including a cylindrical one in which 1 / R _{u, k} = 0 . The length L _{u, k of} the auxiliary portion 16 of the input collector 2 is not less than 0.04 of the diameter D of the impeller 1, which is equal to the diameter of a circle circumscribed by the ends 17 of the blades 5 during the rotation of the impeller 1 : L _{u, k} / D≥0.04.

The in Fig. 6 shown annular gap 15 is formed such that the radial impeller converges inwardly, that is, the gap is convergent. In front of the annular gap 15 a vortex extinguisher is arranged, which may be in the form of at least one plate 18, the side edges thereof with the walls of the input collector 2 (FIG. FIGS. 4, 5 ), while the trailing edge 19 in front of the annular gap 15 (FIG. Fig. 6 ) is arranged.

The radial impeller 1 can be provided with an enlarged front windshield 20 and with an enlarged main pulley 21 ( Fig. 5 ). The blades 5 of the radial impeller 1 can be equipped with a main portion 22, the front front edge 23 abuts the front windshield 3, and with a portion which is arranged closer to the axis 6 of the radial impeller 1 and hereinafter referred to as "slat" 24th ( FIGS. 4, 5, 7 . 8th ) referred to as. The main section 22 and the slat 24 (FIG. FIGS. 7 . 8th ) of the blade 5 can be formed in one piece, for example, from a piece of sheet metal ( Fig. 9 ) or in the form of an aerodynamic profile (not shown) or as a composite part ( Fig. 10 ) in such a manner that the slat 24 is attached to the main portion 22 of the blade 5.

The front front edge 25 of the slat 24 can be arranged in the range of the angle of ± 10 ° to the plane which is perpendicular to the axis of rotation 6 of the impeller 1. The side edge 26 may be at an acute angle to the front edge 25 (FIG. Fig. 8 ), wherein the side edge 26 and the front edge 25 are connected to each other by means of a free curve piece, for example a circular arc, which forms a cam 27 of the slat 24. The front front edge 25 of the slat 24 in the projection from the plane which is perpendicular to the axis of rotation 6 of the impeller 1 is curvilinear and extends, for example along a circular arc ( FIGS. 7 . 9, 10 ). The side edge 26 of the slat 24 can be executed with a local radius R _SE , which in the course of the front edge 22 (FIG. Fig. 8 ) increases to the outside.

In order to increase the strength of the slats 24 of the blades 5, the side edges 26 of the slat 24 by means of a ring 28 (FIG. Fig. 5 ) get connected. Similar rings may be disposed at the ends 17 of the blades 5 and also in addition to the already fixed ring 28 at the side edges 26 of a slat 23 (not shown).

Example of preferred embodiments of the impeller assembly with a free radial impeller

In the preferred embodiment, the additional portion 16 of the input collector 2 is formed with a cylindrical inner surface ( 1 / R _{u, k} = 0 ) and with a relative length within a range of L _{u, k} / D = 0.04 ... 006 . The radial impeller 1 of the impeller assembly 1 ( FIGS. 4, 5 ) has not less than six vanes 5, the width H , which corresponds to the distance between the front windshield 3 and the main disc 4 at the location of their overlap with the ends of the blades 5 at the output of the impeller 1, 0.25 ... 0 , 37 of the diameter D of a circle circumscribed by the ends 17 of the blades 5 of the impeller 1: 1 / R _{u, k} = ₀ , L _{u, k} / D = 0.04 ... 0.8, H = (0.25 ... 0.37) D.

In the case where the impeller 1 is equipped with 6 ... 10 blades, the surface of the main portion 22 and the surface of the slat 24 of the blades 5 which encounter them are provided with a single cam or double cam ( Fig. 7 ) Mistake. In the case where the impeller with more than eleven vanes 5 ( FIGS. 9, 11 ), the main portion 22 of the blade 5 may be formed flat. The slat 24 abuts on this main portion in the portion which is perpendicular to the axis of rotation 6 of the impeller 1 in the form of a circular arc, wherein the front edge 25 and the side edge 26 of the slat 24 are interconnected along the circumference. The side edge 26 is provided with a local radius R _SE which is not less than 0.5D and close to the front edge 25 is located and parallel to the axis of rotation 6 of the impeller 1 (ie equal to endless) close to the main disk 4 ( FIGS. 4, 5 . 8th ) runs.

In the projection of the plane perpendicular to the axis of rotation 6 of the impeller 1, the straight line connecting the axis of rotation 6 of the impeller 1 with the cam 27 of the slat 24 does not exceed the portion bounded by rays falling within a range of Δ t = ± 0.05 of the angular step t with respect to the straight line, the axis of rotation 6 of the impeller connects to an abutment point 29 of the front edge of the blade 5A, the direction of rotation of the front windshield 3 follows or lies on the straight line ( Fig. 12 ). In the case where the radial impeller 1 is provided with enlarged front face plate 20 and enlarged rear plate 21, their diameters are equal to (1.1 to 1.2) D and (1.05 to 1.15, respectively ). D, s. the Figures 5 . 11 , In the meridian section between the generatrices of the front windshield 20 and the main disk 21 in the direction from the axis of rotation 6 to the ends 17 of the blades 5 of the impeller is a non-diverging channel ( Fig. 5 ) educated.

$$\mathit{z}\mathit{=}\left(-\mathit{0}\mathit{,}\mathit{39}\mathit{\pm }\mathit{0}\mathit{,}\mathit{01}\right)\mathit{x}-\mathit{0}\mathit{,}\mathit{27}$$

$${\mathit{r}}^{\mathit{2}}\mathit{=}{\mathit{x}}^{\mathit{2}}\mathit{+}{\mathit{y}}^{\mathit{2}}\mathit{,}$$

worin

z=Z/D

eine relative Koordinate ist, die längs der Drehachse 6 des radialen Gebläserads 1 in Richtung von der Hauptscheibe 4 zum Eingang 7 des Gebläserads 1 gerichtet ist,

x=X/D

eine relative Koordinate ist, die senkrecht zur Drehachse 6 des radia- len Gebläserads 1 steht,

y= Y/D

eine relative Koordinate ist, die senkrecht zur Achse 0Z und Achse 0X steht,

r=R/D

ein relativer laufender Radius des Gebläserads 1 ist,

R

der laufende Radius des Gebläserads 1 ist,

X, Y, Z

die laufenden Koordinaten sind,

D

der Durchmesser des radialen Gebläserads 1 ist, der gleich dem Um- fangsdurchmesser ist, der durch die Enden 17 der Schaufeln 5 wäh- rend deren Drehung umschrieben wird.

In the case where the impeller 1 is provided with eleven or more blades 5, the main portion 22 of the blades 5 must be formed flat with a rectilinear front edge 23. The generatrix of the front windshield 3 at the abutting portion of the front front edge 23 of the main portion 22 of the blade 5 (FIG. Fig. 5 ) is carried out in accordance with the following equations: $$\mathit{y}\mathit{=}\left(\mathit{0}\mathit{.}\mathit{29}\mathit{\pm }\mathit{0}\mathit{.}\mathit{01}\right)\mathit{x}\mathit{+}\mathit{0}\mathit{.}\mathit{37}$$

$$\mathit{z}\mathit{=}\left(-\mathit{0}\mathit{.}\mathit{39}\mathit{\pm }\mathit{0}\mathit{.}\mathit{01}\right)\mathit{x}-\mathit{0}\mathit{.}\mathit{27}$$

$${\mathit{<figure-callout\; id="2"\; label="r"\; filenames="imgf0001.png,imgf0005.png"\; state="\{\{state\}\}">r</figure-callout>}}^{\mathit{2}}\mathit{=}{\mathit{x}}^{\mathit{2}}\mathit{+}{\mathit{<figure-callout\; id="2"\; label="y"\; filenames="imgf0001.png,imgf0005.png"\; state="\{\{state\}\}">y</figure-callout>}}^{\mathit{2}}\mathit{.}$$

wherein

z = Z / D

a relative coordinate which is directed along the axis of rotation 6 of the radial impeller 1 in the direction of the main disk 4 to the inlet 7 of the impeller 1,

x = X / D

is a relative coordinate that is perpendicular to the axis of rotation 6 of the radial impeller 1,

y = Y / D

is a relative coordinate that is perpendicular to axis 0Z and axis 0X ,

r = R / D

is a relative running radius of the impeller 1,

R

the running radius of the impeller 1 is

X, Y , Z

the current coordinates are,

D

is the diameter of the radial impeller 1 which is equal to the circumferential diameter circumscribed by the ends 17 of the vanes 5 during their rotation.

Operation of the invention

The equipment of the input collector 2 with an additional portion 16, whose inner surface has a weak curve 1 / R _{u, k} → O and is combined with surfaces of the convergent input portion 12, ensures alignment along the cross section of the collector 2 of a velocity profile in front of the edge 14 the output section 13 of the input collector 2 and for a uniform flow at the inlet 7 to the radial impeller 1 and on the surface of the front windshield 3 (or 20) of the impeller 1. Overall, the arrangement of the additional portion 16 of the input collector 2 increases the coefficient of the static pressure ψ _S. (which is equal to the relationship of the static pressure P _SV from the product of the air density ρ and the square of the peripheral velocity u of the impeller blade ψ _S = 2Psv / ρ u ² ) in the absence of a vortex extinguisher.

The arrangement of a vortex extinguisher, which is embodied, for example, in the form of a plate 18 with a trailing edge 19 arranged in front of the annular gap 15, ensures interruption of the annular flow occurring at the output surfaces of the rotating front-face disk 3 and the stationary input collector 2 is formed. As a result, the value of the static component of the total pressure before the annular gap 15 is increased.

Thereby, the momentum of the annular flow flowing from the annular gap 15 to the inner surface of the front windshield 3 is increased. The blown air stream delays the flow separation from the inner surface of the front windshield 3, whereby the width H of the blades 5 can be increased to a value of H = (0.25 ... 0.37) D. The provision of the annular gap 15, which causes the radial impeller to converge inwardly (ie, converge), also promotes the increase in the momentum of the annular flow.

The above is confirmed experimentally and in diagrams of the Figures 13 ... 23 shown. In these diagrams, the fan wheel assembly presumed to be the closest analog [1] to the blower wheel RH31G-4DK.0F / 1R assembled with an electric motor having an outer rotor and an input collector has been taken as a basis. In the impeller assembly, the blades 5 of the impeller 1 were further improved by the slat 24 in the in Fig. 8 shown form was executed. Furthermore, a vortex extinguisher in the form of four plates 18 was installed. An additional portion 16 was interposed between the convergent input portion 12 and the output portion 13 of the input collector 2 with different lengths L _{u, k} / D = 0.032, 0.065 and 0.097 and with a cylindrical inner surface ( 1 / R _uk = ∞) coincident with the surfaces of the convergent input section 12 and the output section 13 of the input collector 2.

The fan wheel assembly [1] with an input collector 2 and the in Fig. 8 The vane 24 shown corresponds to the zero relative length ( L _{u, k} / D = 0 ) of the additional portion 16 of the input collector 2. In order to analyze the aerodynamic and acoustic properties, the impeller assemblies were installed in a similar in-stock casing of a duct fan equipped with sound absorbing Walls was provided with a cross-sectional area S _{K of} the channel, which exceeded the area S _{PK of} the impeller 1 by not less than 2.4 times ( S _K / S _PK ≥ 2.4 ), in a portion which is the axis of rotation. 6 the impeller 1 was vertical.

1. (1) "Prototyp" bezeichnet ein Kanalgebläse mit der Gebläseradanordnung, die als nächstkommendes Analogon [1] mit dem Gebläserad RM31G-4DK.0F/1R genommen wurde, das mit einem Eingangskollektor und einem einen Außenrotor aufweisenden elektrischen Motor zusammengebaut ist.
2. (2)"Prototyp+Vorflügel" bezeichnet ein Gebläserad (1) mit verbesserten Vorflügeln 24 der Schaufeln 5.
3. (3) "Prototyp+Vorflügel+Wirbellöscher" bezeichnet ein Gebläserad (2), das mit einem Wirbellöscher in Form von vier Platten 18 ausgerüstet ist.
4. (4) "Prototyp+Vorflügel+Wirbellöscher+L_u,k /D=..." bezeichnet ein Kanalgebläse (3), dessen Kollektor 2 mit einem Zusatzabschnitt 16 mit der genannten relativen Länge L_u,k /D ausgerüstet ist.
5. (5) "Prototyp+Vorflügel+L_u,k /D=..." bezeichnet ein Kanalgebläse (2), dessen Kollektor 2 mit einem Zusatzabschnitt 16 mit der genannten relativen Länge L_u,k /D ausgerüstet ist.
6. (6) "Die bevorzugte Ausführung der Gebläseradanordnung" bezeichnet ein Kanalgebläse (4), dessen Kollektor 2 mit einem Zusatzabschnitt 16 mit einer relativen Länge L_u,k /D=0,065 ausgerüstet ist.

To the diagrams of the FIGS. 13 to 23 the following is noticed:

1. (1) "prototype" means a duct fan with the impeller assembly taken as the closest analog [1] to the impeller RM31G-4DK.0F / 1R assembled with an input collector and an external rotor electric motor.
2. (2) "Prototype + slat" means an impeller (1) with improved slats 24 of the blades 5.
3. (3) "Prototype + slat + vortex extinguisher" means an impeller (2) equipped with a vortex extinguisher in the form of four plates 18.
4. (4) "Prototype + slat + vortex extinguisher + L _{u, k} / D = ..." denotes a duct fan (3) whose collector 2 is equipped with an additional section 16 of said relative length L _{u, k} / D.
5. (5) "Prototype + slat + L _{u, k} / D = ..." denotes a duct fan (2) whose collector 2 is equipped with an additional section 16 of said relative length L _{u, k} / D.
6. (6) "The preferred embodiment of the impeller assembly" means a duct fan (4) whose collector 2 is equipped with an additional portion 16 having a relative length L _{u, k} / D = 0.065 .

The study carried out showed, as in the diagram of Fig. 13 that the pressure characteristic ψ _S = F ( φ ) (where φ = Q / uS _{PK represents} the output coefficient , where Q is the blower output, u the peripheral speed, S _{PK is} the blower surface S _PK = 0.25 π D ² ) of the channel blower in which an impeller assembly is installed was influenced by the shape of the slat 24 of the blade 5 and by the presence of a vortex extinguisher.

In the diagram ψ _S = F ( φ ) in Figure 14 is a pressure characteristic of a duct blower with a built-fan assembly shown, the impeller 1 is equipped with a slat 24 and an input collector 2, which is provided with an additional portion 16 of different relative length L _{u, k} / D , once with and at other times without vortex extinguisher , It can be concluded from the diagram that the presence of the additional portion 16 of the collector 2 increases the coefficient of the static pressure φ _S , the output coefficient of performance φ remaining the same. Thus, the presence of a vortex extinguisher having the same relative length L _{u, k} / D of the additional portion 2 of the collector also results in an increase in the static pressure coefficient ψ _S.

In the diagram ψ _S = F (L _{u, k} / D) the Fig. 15 with φ = const, it is shown that the coefficient of the static pressure ψ _S for the duct fan with an impeller assembly without vortex extinguisher is increased when the relative length L _{u, k} / D of the additional portion 16 of the input collector 2 is increased. The installation of a vortex extinguisher is shown in the diagram ψ _{S (CD)} = F (L _{u, k} / D) Fig. 16 shows and gives a more intense increase in the values of the coefficient of static pressure ψ _{S (CD} ) of a channel blower with a vortex extinguisher.

Thus, in the case where the values of the output coefficient φ = 0.02 ... 0.03 corresponding to the operating range of the channel blower, the intensity of increasing the static pressure coefficient ψ _{S (CD) is} decided higher than in the case where the relative length is L _{u, k} / D≤0.04D , and lower than in the case where the relative length L _{u, k} / D is 0.04D .

Therefore, the relative length of the additional portion 16 of the input collector 2 L _{u, k} / D ≥ 0.04 is an essential feature of the present invention. The optimum length of the additional portion 16 of the input collector 2, as shown in the diagram ψ _{S (CD)} = F (L _{u, k} / D) Fig. 16 follows, L _{u, k} / D = 0.04 ... 0.8.

The comparison of the values of the coefficient of static pressure of a channel blower with a fan blade arrangement with slats 24 and an additional portion 16 of the input collector 2 with a vortex extinguisher and without a vortex extinguisher, as in the diagram ψ _S = ψ _{S (C} - _D) = F (L _{u, k} / D) of the Fig. 17 with φ = const , confirms the importance of equipping the impeller assembly with a vortex extinguisher as well as with an additional portion 16 on the collector 2 to improve the pressure characteristics.

The change in the shape of the slat 24 and the installation of a vortex extinguisher in the form of at least one plate 18, which is used for increasing the coefficient of static pressure ψ _S (diagrams of FIGS. 13 and 14 ), where the output power coefficient φ = const remains the same, as compared to the nearest analogue [1], as shown in the diagram L _P = F (f) Fig. 18 and from the diagram L _W = F (f) of Fig. 19 indicates an increase in the levels of the noise pressure L _P and the noise power L _W at the entrance of the channel blower for all frequencies f .

However, the design of the input collector 2 with an additional portion 16 having a relative length of L _{u, k} / D≥0.04 and thus the best aerodynamic characteristics, resulted in a noise reduction at the entrance of the duct fan , with the impeller assembly according to the invention was equipped. In the diagrams L _P = F (f) of the FIGS. 20 and 21 is shown that the levels of noise pressure L _P practically at all frequencies f under the conditions of maximum output power ( Fig. 20 ) and a mean output power ( Fig. 21 ) decreased during operation of the duct fan.

Therefore, in the preferred embodiment of the impeller assembly, the presence of a vortex extinguisher, the vane 5 of the recommended shape with the vane 24 and the auxiliary portion 16 on the input collector 2 having a relative length L _{u, k} / D≥0.04, provide essential features for achieving a technical Result for the decrease of the noise level at the entrance of the channel blower, which is equipped with the claimed impeller assembly.

The design of the impeller 1 of the impeller assembly with blades 5 with slats 24 of a cylindrical shape and with a flat main portion 22, the front edge 23 is rectilinear, as well as the embodiment of the front face plate 3 with a hyperbola, whose generatrix along the attachment line of the main portion 22 of the blade 5, simplifies the manufacturing tool for making the impeller 1. This achieves better aerodynamic properties and a lower noise level compared to the closest analog [1].

The design of the impeller assembly with an impeller provided with enlarged disks 20, 21 provides an increase in the coefficient of static pressure of the impeller 1 and, consequently, an improvement in the duct fan with the claimed impeller assembly.

The connection of the side edges 26 of the vanes 24 of the blades 5 by means of the ring 28 increases the rigidity of the impeller and prevents deformation of the blades 5 in the case of a high rotational speed. In the case of large dimensions of the impeller assembly, if necessary, similar rings are secured to the side edges 26 and also to the ends 17 of the blades 5.

The impeller assembly with a free impeller presented in the description of the present invention can be installed in duct and radial fans in helical housings and in pressure pumps. Through the disclosure of the invention, the impeller assembly can be designed and manufactured in specialized equipment. The impeller assembly with a free radial impeller meets the requirement "commercially applicable" for patentability.

Reference and remark list

1

Radial fan wheel 1,

2

Input Panel,

3

Front windshield of the impeller 1,

4

Main disc of the impeller 1,

5

Blade of the impeller 1,

6

Rotary axis of the impeller 1,

7

Entrance to the impeller 1,

8th

Input edge of the front windshield 3,

9

Output of the impeller 1,

10

Outer edge of the front windshield 3,

11

Outer edge of the main disk 4,

12

convergent input portion of the input collector 2,

13

Output section of the input collector 2,

14

Edge of the output section of the input collector 2,

15

annular gap,

16

Additional portion of the input collector 2,

17

End of the bucket 5,

18

Plate of the vortex extinguisher,

19

Trailing edge of the plate of the vortex extinguisher,

20

enlarged front windscreen,

21

enlarged main window,

22

Main section of the blade 5,

23

Front edge of the blade 5,

24

Vane of the blade 5,

25

Front edge of the slat 24,

26

Side edge of the slat 24,

27

Cam of the slat 24,

28

Ring for connecting the side edges 26 of the slats 24,

29

Abutting point of the front edge 23 of the blade 5A, which follows the direction of rotation with the front windshield 3,

R _{u, k}

Radius of the generatrix of the inner surface of the additional portion of the input collector 2,

L _{u, k}

Length of the additional portion 16 of the input collector 2,

D

Diameter of the impeller 1, which is equal to the diameter of a circle, which is circumscribed by the ends 17 of the blades 5 during the rotation of the impeller 1,

R

current radius of the impeller,

X , Y,

Z current coordinates,

x = X / D

relative coordinate which is perpendicular to the axis of rotation 6 of the impeller,

y = Y / D

relative coordinate, which is perpendicular to the axis 0Z and axis 0X ,

z = Z / D

relative coordinate, which is directed along the axis of rotation 6 of the impeller 1 in the direction of the main disk 4 to the inlet 7 of the impeller 1,

r = R / D

relative radius of the impeller 1,

H

Width of the blades 5, which is equal to the distance between the front face disc 3 and the main disc 4 at the outlet 9 of the fan wheel 1,

R _se

Value of the local radius of the side edge 26 of the slat 24 of the blade 5,

t

Angular step from blade to blade,

Δ t

Deviation from the angular step t,

S _K

Channel surface of the fan in the section which is perpendicular to the axis of rotation 6 of the impeller 1,

S _PK = 0.25 π D ²

Surface of the impeller 1,

ψ _S = 2Psv / ρ u ²

Coefficient of static pressure,

psv

static pressure of the blower,

ρ

Air density,

u

Peripheral speed of the blade 5 of the impeller 1,

φ = Q / uS _PK

Output coefficient,

Q

Output power of the blower,

S _PK = 0.25 π D ²

Surface of the impeller 1,

L _P

Level of noise pressure,

L _W

Level of noise power,

f

Frequency in kHz.

Claims (10)

An impeller assembly comprising a free radial impeller having an impeller (1) and an input collector (2), wherein - The radial impeller (1) has a main disc (4) and a front windshield (3), - Blades (5) between these discs (3, 4) are arranged and inclined in relation to the direction of rotation backwards, the input collector (2) has a convergent input section (12) and output section (13), the edge of the output section (13) is arranged between the main disk (4) and the input edge (8) of the front windshield (3) of the fan wheel (1), forming an annular gap (15),
characterized,
in that the input collector (2) is provided with an additional section (16) arranged between the convergent input section (12) and the output section (13) and with an area coincident with the surfaces of the convergent input section (12) and the output section (13 ) of the input collector (2), and is provided with a weakly curved generatrix ( 1 / R _{u, k} ),
further that the length ( L _{u, k} ) of the additional portion is not less than 0.05 of the diameter ( D ) of a circle circumscribed by the ends (17) of the blades (5) of the impeller (1), and
in that a vortex extinguisher (18) is arranged in front of the annular gap (15). Fan wheel assembly according to claim 1,
characterized,
in that the additional section (16) of the input collector (2) has a cylindrical inner surface. Fan wheel assembly according to claim 1 or 2,
characterized,
that the vortex quencher in the form of at least one plate (18) is formed, which is connected to the outer wall of the collector (2). Fan wheel assembly according to claim 1 or 2,
characterized,
in that the annular gap (15) is formed in the radial section and converges inward in the radial impeller. Fan wheel assembly according to claim 1,
characterized,
in that each blade (5) of the impeller (1) is provided with a slat (24) arranged between the joint of the blade (5) with the surface of the front windshield (3) and the axis of rotation (6) of the impeller (1) in which, in the projection of the plane perpendicular to the axis of rotation (6) of the impeller (1), the straight line connecting the axis of rotation (6) with a cam (27) of the slat (24) does not exceed the portion which is blasted which are within a range of ± 0.05 of the angular step of blade (5) to blade (5) with respect to the straight line which the axis of rotation (6) of the impeller (1) with the joint (29) the front edge (23) of that blade (5A) connects, which follows in the direction of rotation of the surface of the front windshield (3). Fan wheel assembly according to claim 5,
characterized,
in that the side edge (26) of the slat (24) of the blade (5) of the impeller (1) forms an acute angle with the front edge (25) of the slat (24). Fan wheel assembly according to claim 5 or 6,
characterized,
in that the front front edge (25) of the slat (24) of the blade (5) of the impeller (1) is formed in the section which is perpendicular to the axis of rotation (6) of the impeller (1) along a circular arc. Fan wheel assembly according to claim 5 or 6,
characterized,
that the diameter of the front disc (20) is 1.1 ... 1.2 and that the diameter of the main disc (21) is equal to 1.05 ... 1.15 of the diameter (D) of a circle passing through the Ends (17) of the blades (5) of the impeller (1) is circumscribed, in the meridian plane a non-divergent plane between the Generatrizen the front windshield (20) and the main disc (21) in the direction of the axis of rotation (6) to the Ends (17) of the blades (5) of the impeller (1) forms. Fan wheel assembly according to claim 5 or 6,
characterized,
that the width (H) of the blade (5) at the output (9) of the impeller (1) is not less than 0.25 of the diameter (D) is a circle defined by the ends (17) of the blades (5) of the impeller (1) is circumscribed. Fan wheel assembly according to claim 5 or 6,
characterized,
that the impeller (1) is provided with at least one ring (28), connecting the side edges (26) of the slat (24) of the blades (5) with each other.

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