DE2809597A1 - Radial air circulation fan for room - has central straight radial fixed blades and curved enclosing rotor blades - Google Patents

Abstract

The radial fan has a housing with an electric motor driven rotor for circulating or suction of fluids in vapour phase. The rotor is not damaged if the fan is contacted by air or gases contg. dust and dirt. The coaxial inlet of the rotor (2) is normal to the fixed blades (10). An equal number of fixed and rotor blades are used. The straight fixed blades at the centre project radially. The rotor blades around the fixed blades are curved.

Description

MACH- :: iF : £ ^l wi

Konrad Reitz _ _

Machine and apparatus construction KG 2809597

Hansastrasse

3470 Höxter 1-Albaxen '* 3'

File number RE 1/78

CENTRIFUGAL FAN

The invention relates to a radial fan consisting of a housing and a preferably arranged in this Electrically driven impeller for circulating and / or sucking off vaporous media, whereby the The impeller consists of a supporting disc mechanically coupled to the drive device, on which the vertical im peripheral area a plurality of curved impeller blades are welded, which in their, from the support disk facing away from the edge area are limited in such a way that the medium to be transported is sucked in and coaxially is discharged radially after passing the impeller chambers.

Such radial fans are known and will be used in particular where there is a risk of pollution in production rooms There is a risk of people working in clearing areas, or a targeted removal of gases is required as part of manufacturing processes is.

Here, for example, is the dedusting or ventilation from coking plants, smelting works, waste incineration plants and also plastic production plants. In such locations where there is a high amount of dust or dirt, the impellers wear out, in particular the impeller blades arranged in these, so that expensive maintenance is required at relatively short time intervals the same must be carried out if the risk of destruction of the impeller as a result of high imbalance has not been taken shall be.

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Increased caking of dust and dirt on the impeller blades can also lead to the impellers become unbalanced, so that the impeller may be destroyed as a result can be done.

Another risk of destruction of the impeller is to be seen in the fact that it hits the impeller at high speed shovel impacting dust or dirt particles destroy them mechanically, which is also a Removal and re-installation of a new impeller with the associated costs.

DTAS 1 063 323 has already proposed for Avoiding these disadvantages the impeller blades in their area opposite from the air inlet one to the rear to give sloping form. Tests have shown, however, that this measure does not solve the actual problem either.

The invention has accordingly set itself the task of ensuring destruction of the impeller or the impeller blades to be avoided, even if it is loaded with air or gases with an increased proportion of dust and dirt will.

The object is achieved in that in the coaxial suction area of the impeller approximately perpendicular to the Support disk level guide vanes are arranged, which are star-shaped from the center of the impeller in the direction of the Impeller blades are aligned.

Here it is necessary and expedient that guide vanes are also provided in accordance with the number of impeller blades are.

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In an advantageous development of the invention it is also provided that the guide vanes are each centered between with the inlet edges of two adjacent impeller blades Distance before these ends.

The solution to the problem is further developed and developed by the measures of the further subclaims.

It should also be mentioned as particularly advantageous that the guide vanes, when they are on a centering sleeve and on are welded to a substructure is designed as an independent unit, so that this is also in the Retrospectively on centrifugal fans that have already been delivered and have them installed in the intake area. This is then useful if in the course of the operation of these fans it has been shown that there is a risk of destruction mentioned above is.

On the basis of two figures, an example embodiment is intended of the invention are described, with reference to detailed individual features of such a radial fan in favor the better understanding of the invention was waived.

Show it:

FIG. 1 an impeller according to the section along the line A-A of FIG. 2; FIG. 2 a plan view of the impeller according to the direction of the flowing medium, the housing was not shown.

A centrifugal fan known per se consists essentially of a housing 1 in which an impeller 2 attached to an impeller hub 3 is arranged such that it can rotate. The impeller hub is driven by an electric motor, not shown here. The impeller 2 in turn consists of a support disk 4 on which curved rotor blades 5 are welded vertically in the peripheral area, which are also held by a cover disk 6 by welding on the edge area opposite the support disk. The cover sheet -H- 909840/0013

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Disk 6 runs in a coaxial suction area 7 to a Inflow nozzles 8, which contributes to noise reduction and has a flow-guiding character.

The width of the impeller blades 5 decreases in the direction of flow, which leads to an increase in efficiency and to Optimization of the flow conditions contributes.

To the driving forces from the impeller hub 3 to the support disc 4- to transmit, a wheel disk9 is provided on the one hand on the impeller hub 3 and on the other hand on the Support plate 4 is mechanically firmly connected.

According to the invention, guide vanes 10 are now arranged within the suction region 7, which are spaced in front of the impeller vanes 5 ends.

Due to the special shape of the same, namely the leading edge rises against the direction of flow of the medium and then A conical drop in the direction of flow, in addition to noise dampening, is highly effective in terms of homogeneous distribution the dust and dirt particles reached in the direction of the impeller blades 5, which process is even closer is to be described.

The guide vanes 10 are in the middle of a centering sleeve 11, which is directed towards the rear, improving the flow conditions, delta-shaped, attached, e.g. welded, while they are also welded to a special substructure 12 at the rear.

At the front, the centering sleeve 11 is closed with a washer 13 through which a fastening screw 14 is guided is.

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Substructure 12, guide vanes 10 and centering sleeve 11 thus form an independent dust guide wheel, which can also be used subsequently fans which have not yet been equipped with this dust diffuser can be installed in the suction area 7. Around to avoid that a dust deflector mounted in this way detaches from its holder, it is provided that the substructure 12 is connected to the support disk 4 by means of a screw connection.

On the other hand, it is more cost effective to take the guide vanes below Under certain circumstances, the centering sleeve can also be welded directly onto the support disk 4 by letting it out, i.e. in the impeller integrate. This is always useful if such a fan is used in locations with particularly high levels of dust and dust Dirt accumulation is provided.

Mode of action:

In the case of an impeller without guide vanes, the dust and dirt particles hit the impeller blades at high speed, especially the rear welding edge, where they give off their kinetic energy and over time file ¹ the welds and other smooth areas of the impeller blades. Dust and dirt particles also settle in the corner areas of the back, which - if the impeller is not to be destroyed by imbalance - must be removed from time to time.

In the case of an impeller with guide vanes, these disadvantages become avoided. This can be explained roughly as follows:

The mass of the dust and dirt particles flowing backwards - i.e. in the direction of the support disk - are there they do not yet carry out any, or only insignificant, rotary motion, with the rotary motion here being the one of the impeller 2 is meant, detected by the guide vane, set in rotary motion and in the direction of the impeller blades thrown off, the direction of the spinning approximately is provided in the middle between two inlet edges of two adjacent impeller blades.

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The speed of rotation of the guide vanes is essential smaller than those of the impeller blades, so that they are hardly endangered. The delta-shaped design of the centering sleeve 11 and the special, already described shape of the "leading edge of the guide vanes 10 promote this directional Effect.

Measurements and practical tests have also shown that a device according to the invention equipped with these guide vanes Radial fan only has to be serviced in almost three times the usual maintenance times - when at all.

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Claims (8)

Sheet -7- Claims Ί. Radial fan, "consisting of a housing and a in this arranged, preferably electric motor driven impeller for circulation and / or suction of vaporous media, the impeller from a with the drive device mechanically coupled support disc, on which a perpendicular in the peripheral area Variety of curved impeller blades welded on are limited in their edge region facing away from the support disk by a cover disk, such that the medium to be transported is sucked in coaxially and discharged radially after passing through the impeller chambers. characterized in that in the coaxial suction area of the impeller (2) approximately perpendicular to the Support disk level guide vanes (10) are arranged, which from the center of the impeller (2) in a star shape in the direction the impeller blades (5) are aligned and end at a distance in front of them. 2. Radial fan according to claim 1, characterized in that corresponding to the number of impeller blades (5) the same number of guide vanes (10). is provided. 3. Radial fan according to claim 1, characterized in that the guide vanes (10) are each centrally end between the inlet edges of two adjacent impeller blades (5) at a distance in front of them. 4. Radial fan according to claim 1, characterized in that the leading edges of the guide vanes (10) increases against the direction of flow of the medium to be transported from the center up to half the length of the same and then falls conically in the direction of flow, that is, in the direction of the support disk (4). Sheet -8-9098 AfI / 0 Π 1 3 Sheet -ψ- 5. Radial fan according to claim 1, characterized in that the guide vanes (10) are raittig a centering sleeve (11), e.g. welded on. 6. Radial fan according to claim 5, characterized in that the centering sleeve (11) in the direction the support disc expires in a delta shape. 7. Radial fan according to claim 1, characterized in that the guide vanes (10) are integrated Components of the impeller (2) are. 8. Radial fan according to claim 1, characterized in that the guide vanes (10) and centering sleeve (11) to create an independent dust deflector on a substructure reinforced with the mechanical structure (12) are welded on. 9 · Radial fan according to claim 5i, characterized in that the centering sleeve (11) at the front with a Disc (13) is closed, through which a fastening screw (14-) is passed, which the dust guide on the Impeller hub (3). Sheet -9-