EP1022469A1 - Radial fan - Google Patents

Abstract

The fan has an induction aperture (28) for its first induction cavity (A1). The second induction cavity (A2) faces the surrounding wall region (19) directly along the scoop crown. There is at least one flow element in the casing outside the running wheel, which can be adjusted by a setting device so that the characteristics of the fan can be altered.

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, and with at least one current conducting element in the housing outside the impeller.

With a radial fan known from EP 0 589 300 B1 this genus is used to improve static pressures and the P / V characteristics 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 performance continued in the DE-GM 29820766 or DE-GM 29820767 further measures for Improve the seal between the blades of the Impeller on the outer circumference and the housing and between the Impeller and the partition proposed. From these publications are also flow control elements in the housing known outside of the impeller, which is used to eliminate turbulent flow components and to build one as possible serve homogeneous flow profile. You decrease thereby the noise and contribute to increasing the Efficiency and fan performance. You need for a predetermined desired characteristic of the blower be optimized. If the characteristic of the Blower by changing other parameters or assemblies is changed or is to be changed, so the flow control elements must at least partially be changed in terms of their geometry or location. This is relatively expensive and complicated in the known blowers.

An object of the present invention is to provide a To create blowers, the characteristics of which to the respective Requirements can be adjusted.

This object is achieved in that at least one flow guide element by means of an adjusting device is adjustable.

Due to the adjustability of a flow control element can the relationships between the work flows and the power flow in the fan can be changed so that a desired change in the blower characteristics or characteristic is possible in a simple manner. Even if one Changing the blower characteristics by changing other parameters or components are brought about, so can this advantageously by the at least one adjustable flow guide are supported, and optimal adaptation is possible in a simple manner.

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

The flow guide element is preferably wing-like trained, on the one hand, the lowest possible flow resistance to form and on the other one as possible to be able to have a great influence on the direction of flow.

Suitable as an attachment point for this flow control element especially the border area between which the blower leaving power flow and the radial in the second Suction chamber of the impeller entering second working flow, this flow control element for distribution between these currents is formed. This will make it easier Way according to the desired needs by downsizing of the power flow and simultaneous enlargement of the working flow, the air outlet quantity and the Efficiency can be increased (flatter characteristic), while in reverse case, that is, by reducing the work flow and power flow increase, steeper Characteristic curves at higher pressure and worse Efficiency can be achieved.

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.

The suction opening is advantageously with a extending into the first suction space, in the manner of a Delivery injector as a ring wall, partial ring wall or Spoiler wall provided trained injector wall, the suction opening and / or the injector wall preferably diagonally to the direction of flow inside the first suction chamber is directed. The one through the intake opening Air flow drawn in from outside leaves the first suction space due to the rotation of the impeller accelerates in radial Direction. Part of this accelerated air flow arrives from the outside as a so-called first working current back into the first suction chamber, the entrance area the rearmost area in front of the Partition is. This first working current flows inside of the first suction chamber past the suction opening. As a result a spoiler effect or one occurs in the injector wall Injector effect according to the jet pump principle which increases the air intake from the outside, this leads advantageously to increase the working pressure, efficiency and blower output so that for example a reduction in efficiency Reduction of the working current could be compensated.

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. A particularly good effect will thereby achieved that the spoiler-like injector wall only in the rear seen in the direction of flow Area of the suction opening extends along this. This leads to the lowest possible with a good injector effect Impairment of the air flow sucked in from the outside.

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. Thanks to the adjustable flow control element a quick and easy adaptation to a changed one Characteristics take place and these are supported.

The characteristics of finished blowers in particular easy to change and to the respective requirements To be able to adapt is advantageously an adjustable Cover element for the suction opening for adjustment the desired intake opening size, which is preferably designed as a swivel disk.

Further, supporting a change in the fan characteristic Measures are a swiveling training of the Intake opening and / or the partition, in particular one Swiveling around the axis of rotation of the impeller. You can the suction opening and the partition either together or be pivoted independently of one another.

A particularly favorable structural design exists in that the suction opening and / or the partition one especially adjustable in rotation in a side wall insert insert are arranged. Thereby is also a simple and easy exchange of Suction opening and / or partition possible. These measures are also independent of the adjustability of flow control elements of inventive importance.

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 axle 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 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 while 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 extension 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 region 19 curved end region 22 of the Circumferential wall 18 connects the circumferential wall region 19 with 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 and divided into the interior of the pot-like impeller 10 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. These 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 area 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 form of a partial ring or a scoop and extends obliquely to the working current A1 directed into the interior of the suction space V1. The air intake 28 itself is also slanted accordingly 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 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 Swiveling 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, you can 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 and is due to the radial fan action accelerated again towards the outside, 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 reached.

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 sealed. 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 flow A2 sucks in the area of the blower outlet 21, compressed and in the one limited by the spiral expansion angle Blow out spiral extension 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 airflow 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, 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 purposes is trained. A bayonet-like or screw-like connection can occur for insertion, and also Usual fasteners can be used. If this insert 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 others 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 figure ψ the delivery number  again. The digit ψ sets the delivery pressure Δp in relation to the dynamic Pressure that the fluid has when its speed equal to the peripheral speed of the impeller is. The delivery number  sets the mean flow rate based on the outside diameter of the wheel Impeller in relation to the peripheral speed of the Impeller. From Fig. 9 it follows that smaller openings steeper characteristic curves with higher pressure, but lower Delivery volume compared to the larger air intake opening surrender. 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 is more or less coverable. 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, a 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 (15)

Radial blower with a pot-like impeller (10), provided with a blade ring (15) on its circumference with a housing (11) accommodating the impeller (10), starting from a part-circle-curved, extending directly along the blade ring (15) Circumferential wall area (19) like a screw in the direction of rotation of the Impeller (10) extends radially to an outlet (21) and two covering the axial end faces of the impeller (10) Has side walls (23, 24; 35), one on one of the side walls (24; 35) arranged partition (26; 46) engages in the pot-like impeller (10) and its Interior into a first and a second suction space (V1, V2), and the first suction chamber (V1) one Suction opening (28; 36; 38-41) is assigned and the second suction chamber (V2) directly along the blade ring (15) facing circumferential wall region (19) and with at least one flow guiding element (29-31) in the housing (11) outside the impeller (10), characterized in that that at least one flow guide element (31) formed adjustable by means of an adjusting device is. Radial fan according to claim 1, characterized in that that the flow guide element (31) wing-like is trained. Radial fan according to claim 1 or 2, characterized in that that the flow guide element (31) in the border area between the power flow (L) leaving the fan and the radially into the second suction chamber (V2) of the impeller (10) entering working current (A2) is arranged and is designed to be divided between these streams. Radial fan according to one of the preceding claims, characterized in that the wing-like Flow guiding element (31) as a whole or in Direction of flow seen rear area (33) around Axis is pivotally mounted. Radial fan according to one of the preceding claims, characterized in that the suction opening (28; 36; 38-41) with one in the first suction chamber (V1) extending, in the manner of a delivery injector as a ring wall, Partial wall or spoiler wall trained Injector wall (20; 34; 42-45) is provided, the Intake opening (28; 36; 38-41) and / or the injector wall (20; 34; 42-45) preferably at an angle to the direction of flow is directed towards the inside of the first suction chamber (V1). Radial fan according to claim 5, characterized in that the spoiler-like injector wall (20; 34; 42-45) only in the rear in the flow direction Area of the suction opening (28; 36; 38-41) along this extends. Radial fan according to one of the preceding claims, characterized in that the injector wall (20; 34; 42-45) on the inside of the corresponding side wall (24; 35) of the housing (11) attached or molded or is integrally connected to this. Radial fan according to one of the preceding claims, characterized in that the suction opening (36) on the Outside of the corresponding side wall (35) of the Housing (11) from a bead-like flow guide ring (37) is surrounded. Radial fan according to one of the preceding claims, characterized in that the suction opening (36) narrowed towards the interior. Radial fan according to one of the preceding claims, characterized in that the suction opening (28; 36; 38-41) round, triangular, teardrop-shaped or kidney-shaped is trained. Radial fan according to claim 10, characterized in that the triangular, teardrop-shaped or kidney-shaped suction opening (28; 39-41) up to the corner area of the first suction chamber (V1), which in Flow direction through the blade ring (15) and Partition (26; 46) is formed. Radial fan according to claim 10 or 11, characterized in that a smaller suction opening (36; 38; 39) to achieve a steeper pressure-volume characteristic or a larger suction opening (28; 40; 41) to achieve this a flattened pressure-volume characteristic is provided is. Radial fan according to one of the preceding claims, characterized in that an adjustable Cover element (48) is provided for the suction opening, which is preferably designed as a swivel disk. Radial fan according to one of the preceding claims, characterized in that the suction opening (28; 36, 38-41) and / or the partition (26; 46) can be pivoted are formed, in particular about the axis of rotation of the impeller (10). Radial fan according to claim 14, characterized in that that the suction opening (28; 36; 38-41) and / or the dividing wall (26; 46) can be rotated in particular in a side wall (24; 35) of the housing (11) attachable Insert part are arranged.

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