CA2851745C

CA2851745C - Fan with sound-insulated fan housing

Info

Publication number: CA2851745C
Application number: CA2851745A
Authority: CA
Inventors: Francois Ceccaldi; Reinhold Both
Original assignee: CFT GmbH Compact Filter Technic
Current assignee: CFT GmbH Compact Filter Technic
Priority date: 2011-10-11
Filing date: 2012-09-19
Publication date: 2017-08-15
Anticipated expiration: 2032-09-19
Also published as: EP2766610A1; CA2851745A1; EP2766610B1; DE102011115530A1; WO2013053342A1

Abstract

A fan (1) that is to be used primarily in underground mining and tunnel construction has a tubular fan housing (2), the inner wall (5) of which has sound-conducting openings (24, 25) that are designed in a specific manner. Said sound-conducting openings (24, 25), which are generally annular, annularly leave enough surrounding material (23) in the segment (16) that supports the fan wheel (9) and the drive (10) in order to thus ensure the secure and precise arrangement of the two components. The inner wall (5) is omitted in the remaining region, said outer wall (4) and/or the coupling wall (3) as such being designed to compensate for the effect of the sound-conducting openings.

Description

DESCRIPTION
Fan with Sound-Insulated Fan Housing The invention relates to a fan with sound-insulated fan housing, preferably for use in underground mining and tunnel construction, with a sound-insulated, generally tubular fan housing having a double wall, between the outer wall and the inner wall of which a sound-insulating filling material is packed, and in the air channel of said double wall, a fan wheel with drive and guiding stub is arranged, wherein the drive supporting the fan wheel with its blades is connected to the inner wall of the double wall, and wherein the double wall consists of segments which are connected detachably to one another by their segment head walls.
Fans or ventilators are used in a great variety of sectors in industry, but also in private sectors, for example, for the purpose of conveying air to be cooled through a cooling unit or else for the purpose of pulling or pushing air through a downstream dust removing device, in order to filter the entrained dust out of the air. Ventilators and blowers are also referred to as fans if they are used in general for suctioning air. In the broadest sense, all said devices are assigned to the so-called compressors, wherein, depending on the field of use, the noise generated by the drive and fan type as well as by the air flowing through is to be absorbed by a sound-insulating wall.
These sound-insulating components are accommodated as a rule between the outer wall and the inner wall of the tubular fan housing and they consist of styrofoam, for example. For the insulation, mineral fiber mats are also used, which are inserted in the gap.
In underground mining it is preferable to use stable filling material components, in order to ensure in that manner the stability of the tube wall which accommodates the drive and the fan wheel. Due to the large air quantities or airflows required underground, the fans have to be correspondingly large and provided with an appropriate sound insulation. Here the sound-insulating filling material should be used to provide insulation both from the noise pollution originating from the drive with the fan wheel located in front and also from the noise pollution originating from the air flowing through. Besides the fact that the structure of such apparatuses for underground use is preferably stable in any case, the entire fan housing is also designed so that it is appropriately stable given the high stress. However, the sound insulation of such apparatuses is relatively minor and it is considerably less than that used in above-ground apparatuses.

An aspect of the present disclosure is directed to the problem of providing a fan with sound insulation, which dampens the noise pollution originating from the airflow flowing through and from the drive and the fan wheel possibly to 80 db and less.
According to an aspect of the present invention, there is provided a fan comprising, a tubular fan housing having an outer wall and an inner wall thereby defining a double wall, the inner wall being provided with sound-conducting openings, the double wall being packed with sound-insulating filling material, the fan housing defining an air channel; a fan wheel with blades, a drive, and a guiding stub arranged in said air channel, wherein the drive supports the fan wheel and is connected to the inner wall of the double wall, and wherein the double wall comprises segments which include segment head walls, the segments being connected detachably to one another via their segment head walls, wherein the sound-conducting openings of the inner wall include openings in the segment in the area of the fan wheel and drive, which are configured to be so large that the inner wall is limited to sections that are necessary for supporting components including the drive and the fan wheel, and wherein the sound-insulating filling material, in a hollow space defined by the outer wall, the inner wall with the sound-conducting openings and the segment head walls, is securely arranged so that the sound-insulating filling material is prevented from one of or both falling out and being pressed out, and wherein one of or both (1) the outer wall and (2) the entire double wall is/are reinforced so as to compensate for the effect of the sound-conducting openings.
In one aspect, the inner wall has sound-conducting openings, particularly in the segment with fan wheel and drive, and the sound-insulating filling material, located in the hollow space formed by the outer wall, the inner wall with the sound-conducting openings as well as the segment head walls, is arranged so that it is prevented from falling out and/or being pressed out, and the outer wall and/or the double wall as such is/are designed so as to compensate for the effect of the sound-conducting openings.
In some embodiments of a fan of such a design, the noise pollution originating from the drive and from the fan wheel as well as from the air or airflows flowing through is absorbed by the "exposed" filling material in such a manner that the noise pollution can thus be reduced to less than 80 db. This has been shown by corresponding internal tests. Even if

2 the fan is operated at full load, the db value is 79. This is achieved in that the dampening surfaces of the filling material are "opened" to the sound generated by the fan wheel and the drive as well as the airflows, so that this filling material can absorb sound practically without being subjected to any influences. In the process, as explained further below, the sound-conducting openings are designed to have a size such that the inner wall, with the exception of the partial areas that are truly needed in order to brace the drive and the fan wheel, is entirely omitted. The resulting potentially reduced stability of the entire fan housing is compensated for since either the outer wall or else the entire double wall is designed so as to compensate for the problem. In some embodiments, this can entail a reinforcement, that is a thickening of the outer wall, but another type of stabilization can also be used or a different shaping of the double wall without resulting in the -uncovering" of the filling material being affected by the inner wall that covers it.
According to an advantageous embodiment of the invention, it is provided that the inner wall of the segments, with the exception of the drive and fan wheel area, is replaced by a sound-permeable covering, or coated with a sound-absorbing coating. Such a coating or covering can be dispensed with if the filling material as such has the required stability in order to ensure that it remains in the provided hollow space in spite of the sound-conducting openings.
In some embodiments, the inner wall in the area of the drive should not be dispensed with, wherein it is provided for this that the inner wall in the area of the blades of the 2a fan wheel and of the holder of the drive is formed in the shape of an annular jacket, to which the drive is immobilized its holder designed as support feet, and the annular jacket in turn is connected via holding supports to the outer wall. This means that the drive with the fan wheel articulated rotatably thereto is connected via the support feet to the remaining inner wall in the form of an annular jacket via support feet, while this annular jacket as such is immobilized via holding supports on the outer wall. As a result, the drive with the fan wheel can be positioned securely within the tubular fan housing, wherein the sound generated by the drive and transmitted via the support feet and the holding supports can still be largely dampened, since the holding supports are located within the insulating material and are tightly enclosed by said material.
In some embodiments, in the segment comprising the drive and the fan wheel, the sound-conducting openings are designed so that they extend, on the one hand, from the segment head wall to the outer margin of the blade, and, on the other hand, from the other segment head wall to the support feet of the drive, in the process advantageously forming an opening ring that is continuous except for any possible supporting struts. In the case of the remaining segments, the segments located either upstream or downstream of this segment which supports the drive and the fan wheel, such an annular jacket is not necessary; here the sound-conducting openings are thus continuous from one segment head wall to the other. In the case of the central segment, the size of the sound-conducting openings has to be selected to be as large as possible, wherein these sound-conducting openings have an annular design.
Depending on the size and the design of the fan, in some embodiments, several segments have to be arranged upstream or downstream with respect to the segment which supports the drive and fan wheel.
In order to allow for some flexibility here, the invention provides for the segment head walls to be shaped so that they from folded edges toward the sound-conducting openings and thus they are shaped so that they form a U shape with the outer wall and the respective segment head wall.
Such segment head walls are optimally suited for a detachable connection of the individual segments, since here, in the central U-shaped arch, which is stabilized by the folded edges, screw connections and the like can be used.
In some embodiments, because of the high stress, in the form of vibrations, for example, the segments have to be firmly connected together in a lasting manner, which can be achieved by detachably connecting to one another the segment head walls of one segment with the segment head wall of

3 the adjacent segment via the clamping parts that press the segment head walls against each other.
These clamping parts thus ensure that the adjacent segments with their segment head walls remain tightly and lastingly connected to one another, but in a manner so that they compensate foi corresponding stresses.
In some embodiments, this "adaptation" to stresses via the clamping parts is achieved in particular in that the clamping parts comprise a spring hook-shaped coupling part adapted to the bore hole in the adjacent segment and an inserted spring. By means of the coupling part, a relatively simple connection between the individual adjacent segments becomes possible, wherein, via the "yielding" clamping parts, it is then ensured that these segment head walls are equally pressed against each other and remain in this connection. As a result of the use of these spring hook-shaped coupling parts, no main or secondary activity is needed, so that a rapid and effective connection of the individual segments is achieved in this manner.
In some embodiments, the lack of securing of the filling material, due to the sound-conducting openings, is replaced by a sound permeable covering or the like. This effect can be promoted, or else replaced, by the fact that the holding supports or holding support rows and the clamping parts are arranged and designed in such a manner that they also secure the sound insulating filling material. As a rule, this applies only to the segment which supports the drive and the fan wheel, but it can also apply to the other segments, if they are provided additionally with such holding supports or holding support rows. It is conceivable here for the holding supports to be provided with additional holding elements or to be provided with an appropriate securing means or the like.
In some embodiments, in order to stabilize the arrangement of the drive and the fan wheel within the fan housing, it can be advantageous to connect the outer wall and the inner wall to one another in the area of the holding supports for the drive via a second row of holding supports, wherein the holding supports of two rows in each case are preferably arranged with mutual offset. Here it is conceivable to use two rows of such holding supports or else multiple rows, depending on how large the fan housing with the drive arranged therein is. The holding supports as such support the annular jacket which in tum is responsible for holding the drive and the fan wheel.
Depending on the design of the entire fan, guiding stubs are used, which ensure, both before the fan wheel and also after the fan wheel, that the air or the airflows are supplied in a controlled manner to the individual blades of the fan wheel, without generating excessive

4 turbulence in the process. This fan wheel can also be used according to some embodiments of the invention in order to reduce the resulting noise pollution, and for this purpose it is provided according to some embodiments of the invention that the guiding stub or its end piece located upstream of the fan wheel in the 15 direction of the arriving air stream is adapted to the head of the fan wheel and designed so that it encloses said fan wheel with a small separation and without interrupting the air stream.
This promotes the steady guidance of the air or airflow, wherein this can be further promoted by having the wall of the guiding stub or of the guiding stubs be replaced by a sound-permeable covering which has a smooth outer surface. Since the guiding stub as.such does not have to withstand high stress, a correspondingly stable filling or sound-insulating material can be used, which provides a large area for dampening the noise generated. This means then that, in the case of the fan housing inner space which extends through the annular channel, sound insulation occurs on both sides, which is particularly advantageous if the guiding stubs are led sufficiently far out into the airflow.
In embodiments of the invention, a fan housing is made available which is provided with a sound insulation that is exposed over a large area, in order to capture the generated noise or sound, and thus dampen it in such a manner that a pollution level of less than 80 db can be achieved. Such a fan can be referred to as a whisperer, because it is much below the standard values and because such a pollution level is not audible at all anymore precisely in underground operation due to the general ambient noise pollution existing at the site. This is achieved in particular in that all the areas of a sound-irapermeable wall that are not used for supporting the drive and the fan wheel are kept exposed, so that, overall, a large annular area is available for absorbing any noise or noise pollution present.
Further details and advantages of the subject matter of some embodiments of the invention can be obtained from the following description of the associated drawing, in which a non-limiting example of a prefened embodiment is represented with the necessary details and individual parts.
Figure 1 shows a section of a fan housing with the fan wheel and the drive as well as with the upstream and downstream guiding stabs, Figure 2 shows a partial cutout with an enlarged reproduction of the fan housing segment that supports the drive and fan wheel, Figure 3 shows a clamping part for securing the adjacent segments in a side view, and Figure 4 shows the clamping part in a head-on view.
The fan 1 shown in Figure 1 is a fan for underground use with a corresponding stable fan housing 2. This fan housing 2 consists of a tubular double wall 3, wherein the outer wall 4 is continuous and the inner wall 5 is interrupted by sound-conducting openings 24, 25 formed in a controlled manner. Between the outer wall 4 and the inner wall 5, a sound-insulating filling material 6 is arranged, which is accommodated and arranged in such a manner that it is not negatively affected by the air stream or airflow that passes by.
On the outside of the double wall 3 of the fan housing 2, suspensions 7, T are provided, for suspending such an element or such a fan 1 reliably, for example, from the gallery lining of an underground gallery.
Inside the fan housing 2, the air channel 8 extends, in which the drive 10 with the fan wheel 9 are arranged in a fixed manner, in order to generate the air stream 42. A guiding stub 11 is located upstream of and a guiding stub 12 is located downstream of the drive 10, so as to achieve a steady and as low-noise as possible a guidance of the air stream 42.
The fan wheel 9, which is rotatably connected to the drive 10, comprises blades 14, 15, which are led with their outer margin 29 close along the inner wall 5 and bent so that the air stream 42 is generated. The fan wheel 9 and the drive 10 are associated with a specially designed segment 16 of the fan housing 2. This fan housing 2 consists in fact of the segments 16, 17 and 18 or also of additional segments. While, in the case of the outer segments 17, 18, it is possible to practically omit the inner wall 5, in the case of the central segment 16, an annular jacket 23 is kept as a remainder of the inner wall 5, and connected via the holding supports 28, 28 to the outer wall 4, so that it can fulfill its supporting function for the drive 10 and the fan wheel 9.
Figure 1 shows a corresponding situation and Figure 2 illustrates it. The annular jacket 23 is connected to the holder 22 or the support foot 27 of the drive 10, wherein, on the facing side or offsett, several such support feet 27 are provided, so that a precise securing and arrangement of the drive 10 in the air channel 8 is ensured.
Figure 2 illustrates furthermore that the central segment 16 can have several holding supports 28, 40, which are arranged in a row, wherein they can be positioned mutually offset with respect to the rows in order to secure at the same time also the filling material 6 arranged in this hollow space.

The hollow space 21 is formed by the outer wall 4 and the segment head walls 19, 30 as well as by the folded edges 33, 34 associated with these segment head walls.
Toward the air channel 8, the inner wall 5 is lacking, with the exception of the annular jacket 23, so that opening rings 32, 32' are formed, where the sound collides without impediment against the filling material packing which absorbs the sound at least partially.
Due to the folded edges 33, 34 on the segment head walls 18, 19 and also 20, the individual segments 16, 17, 18 are advantageously stabilized, which, in the case of the central segment, is further promoted by the holding supports 28, 28' and the annular jacket 23. In any case, in this manner an advantageous noise reduction is already ensured, wherein the sound-absorbing filling material 6 can here also be immobilized additionally by a sound-permeable covering 26. In any case, this sound-permeable covering 26 will largely replace the inner wall 5 in the remaining segments 17, 18. This is shown particularly in Figure 1, where the fan housing 2 is reproduced in section.
In order to be able to connect to one another the individual segments 16, 17, 18, while advantageously protecting from stress, the folded edges 33, 34 on the segment head walls 19, 20, 30 are advantageous, since they can receive the clamping parts 36, 37 which effectively connect the segments to each other, as illustrated in Figure 2. These clamping parts 36, 37 are represented additionally in Figures 3 and 4, wherein such a clamping part 36, 37 has a coupling part 38, which has, for example, a kind of screw head 47 and a screw nut 48. This coupling part 38 additionally has a spring 39, which ensures that the segment head walls 19, 20 are detachably connected to each other in an effective and lasting manner, and pressed against each another. It is conceivable here that these coupling parts 38 are also solid parts, which can be inserted with a spring hook-shaped design of the coupling parts 38 into corresponding bore holes 49 in the two adjacent segment head walls 19, 20. By means of the reinforcement 50, it is achieved that, in the case of corresponding movements, the segment head walls 19, 20 cannot be affected and that as a result the inserted sound-insulating filling material 6 is also immobilized.
Figure 1 shows that not only the sound-conducting openings 24, 25 in the case of the segment 16, but also the corresponding sound-conducting openings 25' in the case of the segments 17, 18, and also at the same time the specially designed guiding stubs 11, 12, effectively perform the sound-insulating function. These guiding stubs 11, 12 have a rounded off design at the free end and they can have a sound-absorbing coating 45 here, while, up to the fan wheel 9 or up to the drive 10, the entire guiding stub 11 or 12 is held only by the supports 46 arranged with some separation, while the wall 44 itself is designed to be sound-absorbing or has a sound-absorbing coating 45. Thus, in any case, the air channel 8, which in fact has an annular shape or design, is delimited both on the inner side and also on the outer side by a sound-absorbing or sound-insulating material. In addition to the supports 46, the end-side reinforced supports 53 are provided for the front part 54 of the guiding stub 11, 12.
On the end piece 52 of the guiding stub 11, which faces the front part 54, this guiding stub is provided with a special shape. This end piece is designed in fact with adaptation to the head 43 of the fan wheel 9 or designed so that it partially encloses said fan wheel, thus allowing a particularly steady guiding of the air stream 42.

Claims

CLAIMS:

1. A fan comprising, a tubular fan housing having an outer wall and an inner wall thereby defining a double wall, the inner wall being provided with sound-conducting openings, the double wall being packed with sound-insulating filling material, the fan housing defining an air channel; a fan wheel with blades, a drive, and a guiding stub arranged in said air channel, wherein the drive supports the fan wheel and is connected to the inner wall of the double wall, and wherein the double wall comprises segments which include segment head walls, the segments being connected detachably to one another via their segment head walls, wherein the sound-conducting openings of the inner wall include openings in the segment in the area of the fan wheel and drive, which are configured to be so large that the inner wall is limited to sections that are necessary for supporting components including the drive and the fan wheel, and wherein the sound-insulating filling material, in a hollow space defined by the outer wall, the inner wall with the sound-conducting openings and the segment head walls, is securely arranged so that the sound-insulating filling material is prevented from one of or both falling out and being pressed out, and wherein one of or both (1) the outer wall and (2) the entire double wall is/are reinforced so as to compensate for the effect of the sound-conducting openings.

2. A fan according to Claim 1, wherein the inner wall of the segments, with the exception of the area of the drive and the fan wheel, is replaced by a sound-permeable covering or coated with a sound-absorbing coating.

3. A fan according to Claim 1, wherein the inner wall, in the area of the blades of the fan wheel and of a holder of the drive, is shaped so that the inner wall forms an annular jacket, to which the drive is immobilized, the holder designed as support feet, and the annular jacket in tum is connected via holding supports to the outer wall.

4. A fan according to Claim 3, wherein the sound-conducting openings are designed so that they extend, from the segment head wall to an outer margin of the blades, and from another segment head wall to the support feet of the drive, thereby forming an opening ring that is continuous except for supporting struts, if any.

5. A fan according to any one of claims 1 to 4, wherein the segment head walls are shaped to form folded edges toward the sound-conducting openings and thus are shaped so that they form a U shape with the outer wall and the respective segment head wall.

6. A fan according to any one of claims 1 to 5, wherein the segment head walls of a segment are detachably connected with the segment head wall of an adjacent segment via clamping parts that press the segment head walls against each other.

7. A fan according to claim 6, wherein the clamping parts comprise a spring hook-shaped coupling part adapted to a bore hole in the adjacent segment and an inserted spring.

8. A fan according to claim 6 or 7, wherein said clamping parts are arranged and designed to immobilize the sound-insulating filling material.

9. A fan according to any one of claims 1 to 8, further comprising holding supports or holding support rows connecting the inner wall to the outer wall.

10. A fan according to claim 9, wherein the holding supports or holding support rows are arranged and designed to immobilize the sound-insulating filling material.

11. A fan according to claim 9 or 10, wherein the holding supports include holding supports for the drive, and the outer wall and the inner wall in the area of the holding supports for the drive are connected to one another via a second row of holding supports.

12. A fan according to claim 11, wherein the holding supports of two rows in each case are arranged with a mutual offset.

13. A fan according to any one of claims 1 to 12, wherein the guiding stub or an end piece of the guiding stub located upstream of the fan wheel in the direction of an arriving air stream is adapted to a head of the fan wheel and designed to enclose said fan wheel with a small separation and without interrupting the air stream.

14. A fan according to any one of claims 1 to 13, wherein a wall of the guiding stub is replaced by a sound-permeable covering which has a smooth outer surface.