EP1022470B1 - Radial fan - Google Patents

Abstract

The fan has two induction cavities, the first (A1) of which has an induction aperture (28), The induction aperture has an injector wall (20) extending into the first induction cavity to act as a feed injector. It is in the form of an annular wall, part annular wall or spoiler wall. and improves the achievable static pressure, working pressure and output.

Description

The invention relates to a radial fan with a pot-like Impeller with a blade ring on its circumference is provided with a housing accommodating the impeller, starting from a part-circle-curved, running directly along the blade ring Circumferential wall area like a screw in the direction of rotation of the Impeller expanded radially to one outlet and two the side walls covering axial end faces of the impeller has, one on one of the side walls arranged partition engages in the pot-like impeller and its interior into a first and a second Divided suction space, and wherein the first suction space Intake opening is assigned and the second suction chamber circumferential wall area running directly along the blade ring is facing.

With a radial fan known from EP 0 589 300 B1 this genus is used to improve static pressures and the P / V characteristic between the impeller and the a labyrinth sealing system on both side walls of the housing intended. To further improve these parameters or the achievable working pressure and the achievable blower output were still in DE-GM 298 20 766 and DE-GM 298 20 767 further measures to improve the seal between the blades of the impeller on the outer circumference and the housing and between the impeller and the partition proposed.

A radial blower is also known from DE 195 01 816 A1 known type mentioned in which to increase the Pressure and the slope of the pressure / volume flow curve measures for the specific design and arrangement of the partition and the entry opening are taken, in particular the arrangement and area of the inlet opening is tried to optimize, even with the help of an adjustable Throttle disc.

A radial fan is known from WO 83/02646, at which a guide tongue for flow guidance of the entering Air is arranged at the inlet opening, but unfolds due to the missing partition in the impeller, none Injector effect, since there is no directed one below this tongue Airflow happens.

The object of the present invention is now to to show further measures by which the achievable working pressure and the efficiency can also be increased can.

This object is achieved by a radial fan solved with the features of claim 1.

The air flow drawn in from outside through the suction opening leaves the first suction chamber due to the rotation of the impeller accelerates in the radial direction. Part of this accelerated air flow comes from outside as so-called first working flow back into the first suction chamber, the entry area being seen in the direction of rotation rearmost area in front of the partition. This first working current flows in the interior of the first suction space past the suction opening. As a result of the invention A spoiler effect or an injector effect occurs according to the jet pump principle, through which the Air intake from the outside is reinforced. This leads to more advantageous Way to the desired increase in working pressure, efficiency and fan performance. A special one good effect is achieved by the fact that the spoiler-like injector wall only in the direction of flow seen rear area of the suction opening extends along this. With a good injector effect, this leads to a possible little impairment of the suctioned in from the outside Airflow.

By the measures listed in the subclaims are advantageous developments and improvements of radial fan specified in claim 1 possible.

This can improve the effect that the suction opening and / or the injector wall obliquely to the flow direction in the interior of the first suction space is directed.

The injector wall is expediently on the inside attached to the corresponding side wall of the housing or molded or integrally connected to this. The intake opening is to improve the flow on the outside of the corresponding side wall the housing by a bead-like flow guide ring surround. The streamlines of the intake airflow are thereby harmonizing and stabilizing what also an increase in efficiency or reduction of losses leads. Advantageously, the suction opening also narrows to the inside, so that the airflow in addition is compressed and accelerated.

The suction opening can be round, but triangular, teardrop-shaped or kidney-shaped suction openings proven to be even cheaper. These extend then preferably up to the corner area of the first Suction chamber in the direction of flow through the blade ring of the impeller and the partition is formed.

Can be used to set a desired fan behavior the suction opening can be varied. There is a small one Intake opening to achieve a steeper pressure-volume characteristic or a large suction opening to achieve this a flattened pressure-volume characteristic is provided. In all of these cases, the injector wall improves the efficiency.

The characteristics of finished blowers too change and adapt to the respective requirements can, is an adjustable cover in an advantageous manner for the suction opening to set the desired Intake opening size is provided, which is preferred is designed as a swivel plate.

Another advantageous measure to optimize the Pressure-volume characteristics, the efficiency and the Blower performance is that inside the case outside of the impeller between the two side walls at least an adjustable flow guide element is arranged is, in particular, wing-shaped and preferably adjustable by means of an adjusting device is. As a location for this flow control element the border area between which the Blower leaving power flow and the radial in the second suction chamber of the impeller entering second Working current, this flow control element for division is formed between these streams.

In preferred structural configurations, this is wing-like Flow guide element as a whole or in Direction of flow seen rear area around an axis pivoted.

Fig. 1

eine Seitenansicht eines Radialgebläses als Ausführungsbeispiel der Erfindung, bei dem die mit der Trennwand versehene Seitenwandung abgenommen, jedoch die Trennwand und die Ansaugöffnung dargestellt sind,

Fig. 2

eine Teilschnittdarstellung des in Fig. 1 dargestellten Ausführungsbeispiels durch die Ansaugöffnung und parallel zur Trennwand,

Fig. 3

eine entsprechende Schnittdarstellung mit einer weiteren Ausführungsform der Injektorwandung,

Fig. 4

einen Teilbereich des Laufrads mit runder Ansaugöffnung in der Draufsicht,

Fig. 5

eine entsprechende Darstellung mit im wesentlichen dreieckförmiger Ansaugöffnung,

Fig. 6

eine entsprechende Darstellung mit tropfen- oder nierenförmiger Ansaugöffnung und einer gekrümmten Trennwand,

Fig. 7

eine entsprechende Darstellung mit einer alternativ ausgestalteten nieren- oder tropfenförmigen Ansaugöffnung,

Fig. 8

eine gegenüber Fig. 6 erweiterte Darstellung mit einer Schwenkscheibe zur Veränderung der Ansaugöffnung und

Fig. 9

verschiedene P/V-Charakteristiken zu den Ausführungen gemäß den Fig. 4 bis 7.

Embodiments of the invention are shown in the drawing and explained in more detail in the following description. Show it:

Fig. 1

2 shows a side view of a radial fan as an exemplary embodiment of the invention, in which the side wall provided with the partition is removed, but the partition and the suction opening are shown,

Fig. 2

2 shows a partial sectional illustration of the exemplary embodiment shown in FIG. 1 through the suction opening and parallel to the partition,

Fig. 3

a corresponding sectional view with a further embodiment of the injector wall,

Fig. 4

a partial area of the impeller with a round suction opening in plan view,

Fig. 5

a corresponding representation with an essentially triangular suction opening,

Fig. 6

a corresponding representation with a drop-shaped or kidney-shaped suction opening and a curved partition,

Fig. 7

a corresponding representation with an alternatively designed kidney or drop-shaped suction opening,

Fig. 8

an expanded compared to FIG. 6 with a swivel plate for changing the suction opening and

Fig. 9

different P / V characteristics to the designs according to FIGS. 4 to 7.

In the embodiments shown in FIGS. 1 and 2 a radial fan is a pot-like impeller 10 rotatably mounted in a screw-like housing 11. The impeller 10 consists of a circular disc Bottom 12, the center of a hub 13 for connection with the drive axis of a not shown for simplicity Drive motor owns. On the radially outer peripheral area of the floor 12 rises perpendicular to the plane of the bottom 12 a plurality of blades 14, one Form blade ring 15. The blades 14 are on one End at the bottom 12 and at the other end with a retaining ring 16 connected by means of bent retaining tabs 17. The Blades 14 are curved and opposite to the radial direction inclined by an angle, which is preferably 26 - 29 °.

The housing 11 consists of a helically shaped Circumferential wall 18, with a curved part-circle Circumferential wall area 19 directly with a very small Gap of less than 1 mm along the blade ring 15 extends, in the exemplary embodiment over an angle of approx. 110 °. However, this angle can vary and between 60 ° and 150 °. This peripheral wall area 19 can provided with a large number of parallel groove-like depressions be that parallel or oblique or curved extend to the axis of rotation of the impeller 10 and opposite Blade ring 15 of the impeller 10 a seal according to Art a labyrinth seal to increase the blower output and work pressure.

From the rear with respect to the direction of rotation A of the impeller 10 The end of the peripheral wall region 19 widens Circumferential wall 18 increasing the radial distance to the axis of rotation of the impeller 10 to a blower outlet 21 out. The peripheral wall 18 thus forms in this Area a spiral expansion angle towards the impeller 10, the peripheral wall 18 in the transition region experiences a slight kink. One against the direction of curvature of the peripheral wall portion 19 curved end portion 22 of the The peripheral wall 18 connects the peripheral wall region 19 to the fan outlet 21. The peripheral wall 18 forms together with two the open sides of the peripheral wall 18th covering side walls 23, 24, the housing 11 cover these side walls 23, 24 also the axial End faces of the impeller 10. To seal this Impeller 10 to the two side walls 23, 24 serve labyrinth seals 25, such as in state of the art at the beginning. The bottom 12 of the impeller 10 is the shape of the adjacent side wall 23 adapted, the in Fig. 2 recognizable, multi-angled cross-sectional shape the bottom 12 causes an additional seal.

A partition extends from the side wall 24 26 inside the pot-like impeller 10 and divided whose interior into a first suction chamber V1 and one second suction chamber V2, which faces the peripheral wall region 19 is. This partition 26 can according to the beginning indicated prior art from the side wall 24 extend obliquely to the bottom 12 of the impeller 10, wherein in principle also an arrangement parallel to the axis of rotation the impeller 10 is possible.

The side wall 24 has an air intake opening 28 provided, which opens into the first suction chamber V1. This kidney or teardrop-shaped air intake opening 28 extends from the middle area of the first suction chamber V1 their tapered end to the corner of this first Suction chamber V1 into that of the partition 26 and the Blade ring 15 is formed on the outflow end region becomes. The working current A1, which will be discussed in more detail later flows into the interior of the work space V1 this air intake opening 28 past. An injector wall 20 encompasses the rear in the flow direction Area of the air intake opening 28 in the manner of a partial ring or a blade and extends obliquely to the working current A1 directed into the interior of the suction space V1. The air intake opening 28 itself is also obliquely ins Interior of the suction chamber V1 directed.

Three flow guiding elements designed as flow islands 29 - 31 in the interior of the housing 11 are as Connecting elements between the two side walls 23, 24 trained and serve for elimination of turbulent flow components (vortex zones) and to Establishing a flow profile that is as homogeneous as possible. turbulent Currents would produce the desired flow hinder and cause increased noise. The adjustable flow guide element 31 is wing-shaped and in the border area between the directed to the blower outlet 21 and there the blower leaving power flow and into the suction chamber V2 backflow working stream 2 (A2) arranged. The Flow guide element 31 consists of a front, non-moving area 32 and a rear, pivotable area 33, with the Swivel an adjusting device, not shown is provided, through which the pivotable region 33 actuated or set from outside the housing can be. In a modification of the flow guide element shown 31 this can also be made in one piece and be pivotable as a whole. In addition, too the other flow guide elements 29 and 30 and any further flow guide elements designed to be pivotable his.

In the following, the mode of operation of what is shown and described radial fan, wherein here functions of radial and cross-flow fan technology as well as the side channel compressor technology are. Depending on the design and execution, one dominates or other technique.

When the impeller 10 rotates in the direction of rotation A, this acts Impeller 10 in the area of the first suction chamber V1 as a radial fan. Outside air is drawn in through the air intake opening 28 in sucked the first suction chamber V1 and over the circumferential area of the first suction chamber V1 radially through the blade ring 15 accelerated to the outside. This accelerated air flow divides outside into a working current A1 and one Working current A2 on. The working current A1 comes in again the first suction chamber V1 back and is by the radial fan action accelerated outward again, whereby a substantial part of this work flow on the opposite End of the first suction chamber V1 in the by the Spiral expansion angle formed spiral expansion area arrives.

According to FIG. 2, this working flow A1 passes through the air intake opening 28. There is a redirection and acceleration on the spoiler-like injector wall 20. This creates a suction effect based on the jet pump principle, reinforced by the air from the outside the air intake opening 28 is sucked in and accelerated, which leads to the desired increase in efficiency, the Working pressure and the achievable blower performance leads.

The impeller 10 is on in the area of the second suction chamber V2 its two axial end faces through the side walls 23, 24 tightly closed. Forms towards the interior the partition 26 has a tight seal, and on which the Partition opposite peripheral edge region 19 takes place also by small column or if necessary Labyrinth sealing system sealing the impeller 10. This therefore works in the area of the second suction chamber V2 exclusively as a cross flow fan, which is the working current A2 draws in the area of the blower outlet 21, compresses and in the one limited by the spiral expansion angle Blow out spiral expansion area or diffuser. The radial fan thus works in part as a two-stage Blower with a formed by the first suction chamber V1 as a radial fan stage and one by the second suction chamber V2 formed as a cross-flow fan working level. Through the adjustable flow control element 31 can be the ratio between the working current A2 and the power flow to the fan outlet 21 L can be set. By increasing the working current A2 and thus a reduction in the power current becomes a higher air flow with better efficiency and reached lower pressure (flat characteristic curve), while in vice versa a higher pressure with worse Efficiency (steeper characteristic curve) is achieved. Depending on Use case, therefore, the respective way of working Adjustment of the pivotable range 33 set and also be changed.

In the further embodiment shown in FIG. 3 an injector wall 34 is in contrast to the injector wall 20 in one piece with the correspondingly modified Side wall 35 connected. Same or equivalent Components are otherwise with the same reference numerals provided and not described again.

In contrast to the first embodiment, here is one much smaller air intake opening 36 is provided also tapers inwards towards the suction chamber V1, which too compression and acceleration of the intake air flow leads. Furthermore, this air intake opening 36 is on the outside of a bead-like flow guide ring 37 surrounded, also in one piece on the side wall 35 is molded and for harmonization and stabilization the streamlines of the intake air flow.

In the two exemplary embodiments, the spoiler-like surrounds Injector wall 34 like a ring, the air intake opening 28 or 36 on opposite to the flow direction End region of this air intake opening 28 or 36. In Modification to this could also be a tubular or Kick injector wall.

Another modification is that the air intake opening and / or the injector wall on one in the Side wall 24 or 35 insert insert arranged are interchangeable for different applications is trained. A bayonet or screw-like connection, whereby also Usual fasteners can be used. If this insert part is essentially circular is formed, a pivoting of the Position of the air intake opening and the angle of the partition will be realized.

In the examples shown in Figs. 4 to 7 are different designs of air intake openings 38 - 41 provided. 4 is an approximation centrally arranged round air intake opening 38 with a corresponding injector wall 42, in Fig. 5 in substantially triangular air intake opening 39 with a corresponding injector wall 43 on the air outlet side End region of the suction chamber V1, in Fig. 6 a drip or kidney-shaped air intake opening 40 with a corresponding Injector wall 44 and a modified one in FIG. 7 drop-shaped or kidney-shaped air intake opening 41 with a corresponding injector wall 45 shown. It is 6 instead of the linear partition 26 of the rest Embodiments of an S-shaped curved partition 46 provided at the curvature of the air intake opening 40 in is adapted to a certain extent.

Because of the different positions, the different Shape and the different size of the air intake openings 38 - 41 the P / V characteristics of the Blower can be set or preselected. In Fig. 9 the corresponding P / V characteristics a to c are shown, the air intake openings 38 to 41 in this Order are assigned. This in the blower technology The usual P / V characteristics are given by the pressure digit ψ the delivery number ϕ again. The digit ψ sets the delivery pressure Δp in relation to the dynamic Pressure that the medium has when its speed equal to the peripheral speed of the impeller is. The delivery number ϕ sets the mean flow rate based on the outer wheel diameter of the Impeller in relation to the peripheral speed of the Impeller. 9 shows that smaller openings steeper characteristics with higher pressure, but lower Delivery volume compared to the larger air intake opening result. In all cases, however, the injector walls increase 42 to 45 - as already described - the Efficiency, the achievable working pressure and the achievable Fan power.

The arrangement according to FIG. 6 is somewhat expanded in FIG. 8 shown. In addition, one is parallel to one Rotation axis of the impeller 10 arranged pivot axis 47 pivotable swivel plate 48 is provided, through which the Suction opening 40 can be covered more or less. hereby the air intake cross section can be changed, so that in principle the characteristic curves or Characteristics can be set as required can. Instead of a swivel plate 48 can of course other means of covering occur through which the Cross section of the air intake opening 40 or the air intake openings of the other embodiments changed can be.

As an adjustment device for adjusting the flow guiding element a lockable one is suitable, for example Adjustment knob or rotary lever. Furthermore, one could Motorized adjustment device may be provided, for example in the event that the fan characteristic over a control device is controlled or regulated. in the The simplest case can be such an adjustment device also from an engagement recess for attaching a Screwdriver or the like consist.

Claims (12)

1. Radial-flow fan with a pot-type impeller (10) fitted with a blade ring (15) on its circumference, with a housing (11) containing the impeller (10), which, starting at a circumferential wall area (19) with a circular arc curvature, which extends directly along the blade ring (15), radially widens in the manner of a volute in the direction of rotation of the impeller (10) towards an outlet (21) and has two side walls (23, 24; 35) covering the axial end faces of the impeller (10), whereby a dividing wall (26; 46) on one of the side walls (24; 35) extends into the pot-type impeller (10) and divides its interior into a first and a second suction chamber (V1, V2) and whereby a suction port (28; 36; 38-41) is assigned to the first suction chamber (V1) and the second suction chamber (V2) is adjacent to the circumferential wall area (19) extending directly along the blade ring (15), characterised in that the suction port (28; 36; 38-41) is provided with an injector wall (20; 34; 42-45) extending in the first suction chamber (V1) and designed in the manner of a discharge injector as a ring wall, part-ring wall or spoiler wall, whereby the spoiler-type injector wall (20; 34; 42-45) extends along the suction port (28; 36; 38-41) only in its rear area as viewed in the flow direction.
2. Radial-flow fan according to claim 1, characterised in that the suction port (28; 36; 38-41) and/or the injector wall (20; 34; 42-45) is/are oriented at an angle to the flow direction in the interior of the first suction chamber (V1).
3. Radial-flow fan according to any of the preceding claims, characterised in that the injector wall (20; 34; 42-45) is mounted on or integral with or connected to form a single piece with the inside of the corresponding side wall (24; 35) of the housing (11).
4. Radial-flow fan according to any of the preceding claims, characterised in that the suction port (36) is surrounded by a bulbous flow guide ring (37) on the outside of the corresponding side wall (35) of the housing (11).
5. Radial-flow fan according to any of the preceding claims, characterised in that the suction port (36) narrows towards the interior.
6. Radial-flow fan according to any of the preceding claims, characterised in that the suction port (28; 36; 38-41) is designed circular, triangular, drop- or kidney-shaped.
7. Radial-flow fan according to claim 6, characterised in that the triangular, drop- or kidney-shaped suction port (28; 39-41) extends to the comer area of the first suction chamber (V1) formed in the flow direction by the blade ring (15) and the dividing wall (26; 46).
8. Radial-flow fan according to claim 6 or 7, characterised in that a smaller suction port (36; 38; 39) for a steeper pressure-volume characteristic or a larger suction port (28; 40; 41) for a flatter pressure-volume characteristic is provided.
9. Radial-flow fan according to any of the preceding claims, characterised in that an adjustable covering element (48) preferably designed as a swashplate is provided for the suction port (40) to adjust the suction port to the desired size.
10. Radial-flow fan according to any of the preceding claims, characterised in that a flow baffle element (31) designed in particular like an aerofoil and preferably adjustable by means of an adjusting device is located in the housing (11) outside the impeller (10) between the two side walls (23, 24).
11. Radial-flow fan according to claim 10, characterised in that the flow baffle element (31) is located in the boundary area between the power flow (L) leaving the fan and the working flow (A2) radially entering the second suction chamber (V2) of the impeller (10) and is designed for distribution between these flows.
12. Radial-flow fan according to claim 10 or 11, characterised in that the whole of the aerofoil-like flow baffle element (31) or its rear area (33) as viewed in the flow direction is pivoted about an axis.

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