Patent Application
20150147170
The invention relates to a modular fan unit of a diagonal and/or axial fan.
Such modular fan units are used as part of a filter fan for industrial systems such as, for example, switching cabinets. Here, the modular fan units can be configured as fans that blow air out or fans that suck air in.
For example, German utility model DE 20 2009 017 511 U1 of the applicant discloses a modular fan unit. The modular fan unit has a fan with an axial fan runner or a diagonal fan runner as the flow drive of the modular fan unit, and it is screwed to a filter frame by means of a fastening flange of the housing of the modular fan unit. As protection for the modular fan unit or as protection against accidental contact, the housing of the modular fan unit has a protective grid on both sides. With this modular fan unit, the housing is divided perpendicularly to the axis of the fan runner in the area of the housing edge into at least two detachably joined housing parts, namely, the motor holding part and the air inlet part. The motor holding part as well as the air inlet part are both configured in one piece and they comprise a protective grid structure. The protective grid structure of the motor holding part has a motor receptacle with fasteners in order to fasten the fan. The division of the housing into two halves, together with the one-piece configuration, permits a very simple installation of the fan in the housing of the modular fan unit. Moreover, as a result, the housing and the modular fan unit are very easy and cost-effective to manufacture, and the design of the modular fan unit can be very compact.
Modular fan units of the generic type can be arranged in the form of a stack in order to create an air-handling system. For example, U.S. Pat. No. 8,398,365 B2 describes such an air-handling system in which several modular fan units having rectangular outer contours are arranged in the form of an air-handling system. The rectangular outer contour makes it possible to arrange the modular fan units as close to each other as possible in the radial direction, thereby increasing the packing density of the modular fan units. A drawback of such air-handling systems lies in the noise emission. In this context, the cited U.S. patent teaches lining the outside of the airflow duct with noise-attenuation materials such as fiberglass-reinforced plastic and foam. Modular fan units with such linings, however, are laborious to manufacture. Moreover, such linings take up a great deal of installation space so that the outer dimensions of the modular fan unit are increased and thus the packing density is diminished.
The objective of the invention is to put forward a modular fan unit that generates a minimum amount of noise, whereby the outer dimension of the modular fan unit is minimized.
According to the invention, this objective is achieved by a modular fan unit having the features of independent claim 1. Advantageous refinements of the modular fan unit can be gleaned from subordinate claims 2 to 7.
According to the invention, the modular fan unit has a housing that has been provided with an inlet opening and an outflow opening. The housing accommodates a fan, whereby the fan can be an axial fan or a radial fan. In any case, the fan conveys the air at least in the axial direction. The housing is divided perpendicularly to the middle axis of the fan into at least two housing halves that are joined to each other, namely, the motor holding part and the air inlet part. The housing forms a chamber in which the blades of the fan are accommodated so as to rotate around the axis of the fan. Moreover, the housing has a circumferential, radially extending edge in the vicinity of which the housing has a thickness B extending in the axis direction of the fan. The motor holding part has a dimension R as the maximum extension in the edge area in the axis direction of the fan. Moreover, the chamber has an extension in the axis direction of the fan at the height of the dimension L, whereas the extension of the air inlet part in the axis direction of the fan has a dimension T in the area of the chamber. By selecting a ratio of the dimension B to the dimension R with respect to the ratio of the dimension L to the dimension T within the range from 0.9 to 1.2, the noise emission of the fan during operation is minimized. As a result, no subsequent measures have to be taken to damp the noise that is emitted. Noise-damping layers that would increase the physical size of the modular fan unit are not necessary, as a result of which the outer diameter of the modular fan unit is kept to a minimum.
It has proven to be advantageous for the diameter of the chamber to be approximately 1.04 times larger than the outer diameter of the fan runner. This creates a gap between the outer diameter of the fan runner and the diameter of the chamber that is about 2% of the outer diameter of the fan runner, as a result of which the noise emission of the fan during operation is further minimized.
In an advantageous embodiment, the housing, as seen in a top view, has an essentially rectangular outer contour. As a result, modular fan units according to the invention can be arranged modularly to form an air-handling system, so that several modular fan units with rectangular outer contours can be arranged in the form of an air-handling system. The rectangular outer contour makes it possible to arrange the modular fan units as close to each other as possible in the radial direction, thereby increasing the packing density of the modular fan units.
It has proven to be advantageous for the motor holding part to have a set-back dimension E and for the air inlet part to likewise have the set-back dimension E, whereby the set-back depth a, as the ratio of the set-back dimension E to the maximum axial extension C of the housing in the axis direction of the fan, is within the range from 0.2 to 0.35. Consequently, E=a*c, wherein 0.2≦a≦0.35.
Moreover, it has proven to be advantageous for the ratio of the maximum outer dimension K of the housing to the impeller diameter D to be 1.15 at the maximum. Here, if the outer geometry of the housing is circular, then K refers to the outer diameter. In the case of a rectangular outer contour of the housing, especially an essentially square outer contour, K refers to the edge dimension of the longest side of the housing.
In another advantageous embodiment, the housing has a circumferential wall ring, whereby the wall ring has a circumferential hollow chamber, also referred to below as a hollow chamber ring. The wall ring is formed by the edge area of the air inlet part and/or of the motor holding part. Owing to the configuration as a hollow chamber ring, on the one hand, a high mechanical stability is achieved for the modular fan unit, whereas on the other hand, the noise emission during operation is further minimized.
Further advantages, special features and practical refinements of the invention can be gleaned from the subordinate claims and the presentation below of a preferred embodiment on the basis of the figure.
The figure shows the following:
The diameter DK of the chamber 111 is 4% larger than the outer diameter D of the fan runner. This creates a gap between the outer diameter of the fan runner and the diameter of the chamber DK amounting to approximately 2% of the outer diameter of the fan runner, as a result of which the noise emission of the fan 150 during operation is further minimized.
The motor holding part 120 as well as the air inlet part 130 have a set-back dimension E, whereby the set-back depth a, as the ratio of the set-back dimension E to the maximum axial extension C of the housing 110 in the axis direction of the X-X of the fan 150, has a value of 0.27, that is to say, a=0.27.
The housing 110 has a circumferential wall ring with a square outer contour, whereby the wall ring has a circumferential hollow chamber 115. Owing to the configuration as a hollow chamber ring, on the one hand, a high mechanical stability is achieved for the modular fan unit 100 against bending and twisting, whereas on the other hand, the noise emission during operation is further minimized.
The embodiment presented here is only an example of the present invention and must therefore not be construed in a limiting manner. Alternative embodiments considered by the person skilled in the art are likewise encompassed by the scope of protection of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102013223983.1 | Nov 2013 | DE | national |
