Method of damping of sound waves in different media


(57) Abstract:


Same patents:

FIELD: the booth is assigned for ventilation of the shaft of the Metro.

SUBSTANCE: the booth includes an above the shaft building with air passing windows and an external barrier in the shape of a ring-type housing. The housing is fulfilled in the shape of a expanding upwards funnel with sound reflecting surface. A hollow gap is between the housing and the above the shaft building.

EFFECT: reduces noise levels with the aid of a single element out of sheet material.

1 dwg

Noise suppressor // 2338964

FIELD: physics; heating.

SUBSTANCE: suppressor is intended for decrease of aerodynamic noise in air ducts of mechanical ventilation and air conditioning systems. Suppressor contains the body in cavity of which there are mounted acoustic dissipation elements pairwise contacting at inlet, forming tapering air passage channels and provided with convex fairings in contact points, as well as swing-out mechanism consisting of levers and control rods rigidly mounted at end faces of acoustic dissipation elements by washers and cotters.

EFFECT: higher efficiency of noise suppression within all the operation modes of ventilation and air conditioning systems.

3 dwg

FIELD: machine building.

SUBSTANCE: suppressor is intended for reduction of hydrodynamic noise level emitted by liquid flow in pipelines. In closed cavity of hydrodynamic noise suppressor, pliable element is installed, for instance, hose, ends of which are connected to nipples withdrawn outside casing, pliable element is filled with air of pressure equal to maximum operating pressure of liquid, and free space of cavity is filled with loose or deformable substance, for instance, sand or rubber balls with diameter of up to 5 mm.

EFFECT: lower level of hydrodynamic noise level downwards hydrodynamic noise suppressor at all working modes by pressure, and also exclusion of necessity for adjustment and control.

2 cl, 1 dwg

FIELD: machine building.

SUBSTANCE: invention refers to procedure of noise suppressing. The noise suppressor consists of a case, of inlet and outlet branches and of a sound absorber. The sound absorber includes a rigid wall. A profiled layer out of sound absorbing material is attached to this wall. Sound absorbing material is produced by alteration of semi-sphere or partially spherical surfaces so, that between the wall and the layer of sound absorbing material there are continuous intervals alternating with air intervals formed with semi-sphere. The profiled layer is also attached to a perforated element of the case. This profiled layer consists of sound absorbing material obtained at alternation of semi-sphere or partially spherical surfaces. This arrangement facilitates alteration of continuous and air gaps formed with semi-sphere between the perforated element of the case with acoustic transparent material and the layer of sound absorbing material. Also the profiled layer at the rigid wall is a mirror reflection of the profiled layer at the perforated element of the case relative to symmetry line 0-0 of the solid profiled layer.

EFFECT: increased efficiency of noise suppressing.

3 dwg

FIELD: machine building.

SUBSTANCE: here is disclosed element of silencer consisting of case with flap cover. The case is filled with sound absorbing material placed in a protective shell. Walls of the case are formed with a sound absorbing structure made as cylinder perforated coaxial shells - internal and external ones. Between the shells there is installed a sound absorber made out of at least one profiled sheet. Also, profile of the sheet in cross section can be rectangular or trapezoidal.

EFFECT: improved acoustic characteristics in region of low, medium of high frequencies.

3 dwg

FIELD: machine building.

SUBSTANCE: device is designed for damping noise in flow through channels. The sound absorbing flow-through channel device forms at least two flow through channels having an inlet orifice and an outlet orifice. The flow-through channels at least partially are restricted with three walls dissipating acoustic energy; the walls are formed with a package of the first, second and third sheets forming flow-through channels between them. Each of the said first, second and third channels is equipped with at least one lug and/or recess. The said lug partially enters the recess, so that the outlet orifice of the flow-through channel can not be visualised through the inlet orifice and vice versa.

EFFECT: additional dissipation of sound energy.

17 cl, 20 dwg

FIELD: machine building.

SUBSTANCE: proposed device comprises, at least, one bent pipe length with inner wall lined by sound absorbing material. Note here that said bent pipe length houses at, least, one air guide device for flow optimisation made up of acoustic separator with its sheet metal jacket covering central absorbing core and provided with micro perforations on inner or outer lateral surface. Note also that nonperforated inner or outer lateral surface of said jacket includes usual perforations with their specific area making, at least, 20%.

EFFECT: higher noise absorption factor.

5 cl, 2 dwg

FIELD: machine building.

SUBSTANCE: sound damper is designed to suppress sound radiation into environment in systems for removal of industrial off-gases. A resonant sound damper of reflecting type comprises an acoustically transparent perforated pipeline, the first and second flange put onto edges of this pipeline and an external jacket covering the device along the perimetre of flanges. A set of Helmholtz resonators is installed in a volume limited with the first and second flanges with an acoustically transparent perforated pipeline and a jacket, besides, the volume of each Helmholtz resonator and geometry of its half is selected so that reflected acoustic capacity exceeds the absorbed one, and the band of reflected frequencies for the entire resonant sound damper covers the frequency band of suppressed noise.

EFFECT: ability to operate in a medium of hot industrial gases saturated with vapours of aggressive liquids.

2 dwg

FIELD: machine building.

SUBSTANCE: elbow includes inlet funnel (21), outlet funnel (22) and hole (23). The hole is closed with plug (24). Into hole (23) there inserted is flexible impact-resistant element (26). Flexible impact-resistant element is borne against stop (29) and forms an additional inner surface of the elbow. The stop projects out of the inlet funnel and/or outlet funnel towards the hole. Impact-resistant element (26) has curvature in radial direction and curvature in longitudinal direction. Inner surface of impact-resistant element is aligned with inner surface of the inlet funnel and/or outlet funnel respectively.

EFFECT: higher operating efficiency of elbow.

19 cl, 11 dwg

FIELD: machine building.

SUBSTANCE: device is designed for muffling of hydrodynamic noise sent along liquid medium filling the pipelines. It comprises a metal body with an elastic element, communicated with a pipeline by means of a neck. The elastic element is made in the form of hollow metal discs with bases in the form of membranes arranged in the metal body. Hollow metal discs are arranged in the body concentrically, at the same time there are central holes in them for placement of the neck, which is arranged as detachable, with the possibility of replacement for necks of different length. The metal body is installed on the pipeline by means of its coverage, and in the area of the coverage in the pipeline there are holes, some of which are equipped with plugs for provision of additional tuning of the muffler.

EFFECT: high sound-insulating efficiency in entire range of hydrostatic pressures of working liquid with unified dimensions of a device.

3 cl, 3 dwg