Centrifugal fan

 

The fan is intended for use in the field of power engineering. The fan contains the tail cone with the language. End edge of the latter has the form of a broken line. The latter consists of at least three linear sections. One of the sites is located opposite the impeller with an inclination to the axis of the latter. The remaining two extreme land adjacent to the body and parallel to the axis of the impeller. Extreme sites are located on one straight line. Reduction of noise and increase efficiency of the centrifugal fan. 2 C.p. f-crystals, 4 Il.

The invention relates to the field of power engineering, in particular to the design of centrifugal fans and compressors.

Known vane machine in which to reduce aerodynamic noise applied sloping languages.

A known design of a centrifugal fan, comprising a bladed impeller and a housing that includes a spiral section, diffuser and language between them (Solomonova ie, Chebyshev K. C. Centrifugal fans. Aerodynamic configuration and characteristics. The Handbook. M.: Mashinostroenie, 1980). In this design coming out rabochego interacts with the language of the body and causes an increased noise level at blade frequency or a multiple of it, and is estimated by the formula: f=knz/60 (Hz), where K= 1, 2, 3,... - coefficient ratio; n is the number of revolutions of the impeller in a minute; z is the number of blades of the impeller.

To reduce the noise level from the heterogeneity of flow can be achieved by increasing the clearance between the outer radius of the impeller and the radius of the location of the language. Increasing this distance leads to a gradual reduction in the heterogeneity of the flow and, consequently, reduces the noise level. But the increase of the distance between the impeller and the tongue leads to lower efficiency of the shoulder of the machine.

Known centrifugal fan design, selected as a prototype containing the impeller blades and the casing, consisting of volute, diffuser and tongue at the junction of the spiral portion in the diffuser (G. A. good, S. I. Petrov, N. F. Egorov. The noise of the ship's systems of ventilation and air-conditioning. Leningrad: Sudostroenie, 1974, S. 106, Fig.60). Reducing aerodynamic noise at blade frequency and multiples of it frequencies is achieved through the use of slanted language across the entire width of the spiral casing. This leads to a decrease in the intensity of the impact of uneven velocity field and pressure on the surface of the tongue, resulting in the reduction of noise coming from the inhomogeneity of the flow is remote from the impeller and in this area increased losses, which leads to lower efficiency of the machine. In addition, the use of slanted language increases its length and complexity of the design of the diffuser, so as long sloping language leads to the fact that the gap between the impeller and the tongue, alternating along the length of the language and in some parts of the language, may exceed the permissible limits, which leads to increased energy losses.

The technical result of the present invention is to reduce noise and increase efficiency of the centrifugal fan.

This technical result is achieved in the following way. The centrifugal fan includes an impeller blades and the casing, consisting of volute, diffuser and tongue at the junction of the spiral portion in the diffuser. According to the invention the trailing edge of the tongue has the form of a broken line consisting of at least three straight portions, one of which is located opposite the impeller at an angle to the axis of the latter. Two extreme land adjacent to the housing, parallel to the axis of the impeller.

The proposed form of the end edges of the language allows to reduce the noise level as well as in the prototype, but reducing the length of the inclined part reduces losses to ispolnennym at an angle to the axis of the impeller, and between plot, made with an inclination to the axis of the impeller, and other extreme plots can be done one section perpendicular to the extreme. This is another possible embodiment of edges of the tongue.

It is advisable extreme sites be placed on the same line. This will allow to reduce losses by providing a minimum gap between the impeller and the outer areas of the language. The same clearances will ensure minimal loss. And the noise level will be reduced by the fact that the sloping site located opposite the wheel aligns the velocity and pressure of the stream.

The invention is illustrated by drawings.

In Fig.1 shows a General view of the centrifugal fan.

In Fig.2 is a view As in Fig.1.

In Fig.3 shows the shape of the edges of the tongue and its location relative to the impeller.

In Fig.4 shows another form of the edges of the tongue.

Centrifugal fan (Fig.1 and 2) consists of an impeller 1 with the rotor blades installed in the housing 2 with a spiral channel 3, and a limit cone 4 and the tongue 5 between them.

In Fig.3 shows a stepped tongue 5, which has two extreme plot 6, 7 parallel to the axis of the impeller 1 (Fig.2), and plot the Edge of the tongue 5 may be composed of four sections: two extreme - 6 and 7, section 8 and section 9, perpendicular to the extreme section 7 (Fig.4). At this end zones 6 and 7 can be placed on one line.

During the rotation of the impeller 1, the air or gas enters the impeller 1, receives the energy from the blades of the impeller 1 and extends in the spiral channel 3 of the housing 2 and the diffuser 4, interacting with the tongue 5. While the section 8 of the edges of the tongue 5 aligns the velocity field of the flow, reducing aerodynamic noise. Sections 6 and 7 reduce energy losses, increasing the efficiency of the fan. In the construction shown in Fig.4, when the fan energy loss will be minimal, as the parts 6 and 7 is removed from the impeller 1 in the radial direction (i.e. parallel to the axis of the impeller 1).

Thus, the proposed design can reduce noise, increase efficiency and to use a more compact construction of the diffuser by reducing the length of the inclined section 8 compared with the design of the prototype.

Claims

1. Centrifugal fan comprising an impeller with blades, which are accommodated in the housing, containing a spiral outlet channel and the tail cone with the language between them, characterized in that the end edge of the tongue has come against the impeller at an angle to the axis of the latter, while the two extreme of the site, adjacent to the housing, parallel to the axis of the impeller.

2. Centrifugal fan under item 1, characterized in that at one extreme, the plot is connected with a plot, made at an angle to the axis of the impeller and between the plot is made at an angle to the axis of the impeller, and the other extreme of the plot made more plot, perpendicular to the extreme.

3. The centrifugal fan according to p. 2, characterized in that the end zones are located on one straight line.

 

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SUBSTANCE: invention relates to electric compressors, turbocompressors for supercharging internal combustion engines, air blowers and other vane machines. Proposed high-speed rotor of blower provides practically complete elimination of rotor unbalance owing to provision of minimum tolerable deformation of shaft when rotor parts pack is tightened by nut, thanks to which vibration and noise of turbocompressor in operation are considerably reduced, service life of bearings is increased and rubbing of impeller or turbine of compressor against base members is prevented which improves operating capabilities and reduces energy consumption. For this purpose, according to first design version, rotor is furnished with plates, each placed between end face of compressor impeller bushing and nut. Said plate has concave spherical surface at one side adjoining convex spherical surface of nut, and at other side, flat surface adjoining flat end face of bushing of compressor impeller. Ring groove is made on each bushing of compressor impeller between blades and end face of compressor impeller bushing. According to second version, ring groove is made on each bushing of compressor impeller between blades and end face of compressor impeller bushing provided with concave spherical surface adjoining convex spherical surface of nut.

EFFECT: improved operating capabilities, reduced energy consumption.

3 cl, 2 dwg

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