SU1560740A1 - Noise muffler - Google Patents

Abstract

The invention makes it possible to increase the efficiency of sound attenuation by splitting the flow. The silencer comprises a housing 1 with an inlet 2 and an exhaust 3 apertures, a central bushing 4 with an axial bore 10 and a sound-absorbing cylinder 5. The radial distance between the respective adjacent surfaces of the casing 1 and the cylinder 5, the latter and the bushing 4 is determined by the given formula. Air through the opening 2 enters the silencing cavity, is divided into flows flowing through the axial opening 10 of the sleeve 4 and the annular gaps formed between the adjacent surfaces of the sleeve 4 and the cylinder 5, the latter and the housing 1, and is ejected from the silencer through the opening 3. 1 silt

Description

one

(21) 4468695 / 25-06

(22) 06/15/88

(46) 04/30/90. Bul Number 16

(71) Donetsk State Design and Experimental Institute for Complex Mechanization of Mines

(72) B.N. Molchanov, S.K.Ivanov and S.S.Ivanov

(53) 621.43.06 (088.8)

(56) Yudin E.Ya., Terekhin A.S., Fight against noise of mine ventilation installations. M .: Nedra, 1973, p.145, ris.3.36.

(54) NOISE SILENT

(57) The invention improves the efficiency of sound attenuation by

The silencer comprises a housing 1 with an inlet 2 and an exhaust 3 holes, a central bushing 4 with an axial bore 1 0 and / sound-absorbing cylinder 5, Radial distance, respectively, adjacent surfaces of the casing 1 and cylinder 5, the latter and the sleeve 4 by the given formula. Air through the opening 2 enters the silencing cavity, is divided into flows flowing through the axial opening 10 of the sleeve 4 and the annular gaps formed between the adjacent surfaces of the sleeve 4 and the cylinder 5, the latter and the housing 1, and is ejected from the silencer through the opening 3. 1 silt

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ЈО1гозггз2гГ№ТШ 1пшп

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The invention relates to mechanical engineering, in particular to noise suppressors, mainly a fan.

The purpose of the invention is to increase the efficiency of sound attenuation in the high-frequency region.

The drawing shows a silencer, a longitudinal section.

The silencer contains a cylindrical body 1 with an inlet 2 and an exhaust | 3 aperture, a central bushing 4 and a sound-absorbing cylinder 5S interconnected by means of extensions 6 and 7. The housing 1 is formed by an outer casing 8 and coaxially formed to form an annular gap, filled with sound-absorbing material, perforated insert 9. The central sleeve 4 is made perforated, provided with an axial bore 10, and on the side of the inlet 2, with a fairing 11 and filled with sound-absorbing material.

The sound-absorbing cylinder 5 is installed coaxially between the case t and the central sleeve 4, is formed by two coaxially arranged with the formation of an annular gap filled with sound-absorbing material, perforated shells 12 and 13 and provided on the side of the inlet 2 with an additional fairing 14. Radial distance between correspondingly adjacent surfaces housing 1 and cylinder 5, the latter and sleeve 4 is determined by the formula

, 2 h 0.333D - 0.666t - 0.414,

where h is the radial distance between the adjacent surfaces of the housing 1 and the cylinder 5, the latter and the sleeve 4, m;

D - diameter of the connecting pipe of the fan, m;

t is the thickness of the layer of sound-absorbing material in the cylinder 5 and the sleeve 4, m;

d is the diameter of the sleeve 4 at the inlet to the impeller of the fan, m.

To reduce aerodynamic losses, the free section area of the muffler is equal to the free section area at the fan inlet.

The muffler works as follows.

Air through the inlet

2 enters the silencing cavity; it is divided into streams flowing through the axial bore 10, bushings 4 and annular gaps formed between adjacent surfaces of bushings 4 and

the cylinder 5, the latter and the housing 1, and is ejected from the silencer through the opening 3. The sound attenuation effect occurs due to sound absorption in a wide frequency range. And

For given channel sizes, the front of a sound wave at high frequencies, being flat, provides effective sound absorption in sound absorbing material and specified frequencies, which makes it possible to significantly reduce its length compared to known silencers.

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Claims (1)

Invention Formula A silencer, predominantly a fan, containing cylindrical bodies with inlet and outlet openings and a central bushing, interconnected by means of extensions, the casing being formed by an outer casing and installed coaxially with an annular gap filled with a sound-absorbing material, perforated with an insert, and central the sleeve is made perforated, filled with sound-absorbing material, and provided with a fairing on the side of the inlet, characterized in that high noise efficiency in the high-frequency region, it is equipped with a sound-absorbing cylinder mounted coaxially between the housing and the central bushing, formed by two coaxially arranged to form an annular gap filled with sound-absorbing material, perforated shells and provided with an additional opening from the vluhole opening, with a central hole, a chassis, and there is a body in the sleeve, and the body in the center of the sleeve has a body that has a chambered body and has a body in the center of the sleeve. and the radial distance between respectively the adjacent surfaces of the housing and the cylinder, the latter and the sleeve is determined by the formula n h 0.333D - 0.666t - 0.416 - 5 1560740 where h is the radial distance between t and the thickness of the layer of sound-absorbing surfaces of the crushing material in the cylinder and the cylinder, the last and the sleeve, m; and bushings, m; d is the diameter of the sleeve at the inlet D is the diameter of the connecting wheel of the fan, fan pipe, m; m.