401 results about "Acoustic quieting" patented technology

A pump piston assembly has a pump cylinder, at least one hollow piston slidably mounted for reciprocating motion in the pump cylinder, the piston having an inner surface of a first diameter and an outer surface of a second diameter, and a liner sleeve of a different material from the piston mounted on the inner or outer surface of the piston with a close or friction fit to the diameter of the piston surface on which it is mounted. The liner sleeve is of an acoustic dampening material which has a lower acoustic frequency than the piston material and is configured to absorb harmonic acoustic vibrations resulting from reciprocation of the piston in the cylinder.

Systems and methods for measuring and controlling fluid flow comprises an orifice plate defining a variable opening, wherein the orifice plate includes an outer assembly comprising a central opening and an inner assembly extending through the central opening. Another embodiment comprises a plurality of blades disposed parallel to each other, wherein the blades are pivotable along its longitudinal axis and include at least one low-flow blade or partial blade and a plurality of high-flow blades The flow device regulates high and very low volumes of fluid with precision, inexpensively, with superior acoustics, reduced energy, a simpler design, and prevents building infiltration. The high turndown device permits use at lower velocities, thereby reducing noise generation and eliminating need for sound-attenuating liners. The high rangeability device combines several part numbers into fewer parts, thereby streamlining product portfolios. Cost benefits associated with the flow device allow equipment to be scaled back 100:1 rather than legacy 4:1, providing energy savings, fewer product variations, simple and more robust applications. The device meets new and old building fresh air, comfort and energy codes. The flow device can be engineered, selected, and sized without sophisticated software programs.

The invention provides a sound attenuating panel (100) with controllable sound attenuation properties, the sound attenuating panel (100) comprising (a) a sound attenuating unit (200) with cavities (212) with variable dimensions and (b) an infrastructure (300) for controlling the dimensions of the cavities (212) in the sound attenuating unit (200). The sound attenuating unit comprises sound attenuating material with controllable sound attenuating properties, but may also have wave guiding properties, thereby allowing to combine in the sound attenuating unit 200 both sound attenuating properties and optical properties.

The invention discloses a muffling structure which comprises more than two layers of resonant film materials. The adopted film is soft, uneven in surface and has airflow barrier. The surface of the film is uneven on the basis of the soft film, so that the absorption peak of the resonant structure deflects to the low frequency, the absorption of the low frequency is promoted; and moreover, when the medium-high frequency sound is incident from different angles, the sound waves have a chance to reflect on the surface of the film repeatedly; and therefore, the opportunity that the sound waves pass through the airflow barrier film is greatly increased, the strong reflection of the smooth airflow barrier film on the medium-high frequency sound is avoided, most of the medium-high frequency sound can enter the structure to be absorbed, and the absorption of the medium, high and low-frequency sound is considered.

The invention discloses a supporting noise reduction system for a combustion gas turbine mobile power station, and relates to the technical field of prevention of noise pollution. The system comprisesa sound insulation box body used for mounting a combustion gas turbine, wherein the bottom of the sound insulation body is fixedly mounted on a suspending body frame through a sound attenuation system underframe, and wheels are mounted at the bottom of the suspending body frame; an inlet gas sound attenuation system is connected to one end of the sound insulation box body, and an intake air soundattenuation system is arranged above the inlet gas sound attenuation system and communicates with a gas inlet of the sound insulation box body; and a first-stage exhaust sound attenuation system is arranged at the top of the other end of the sound insulation box body, a second-stage exhaust sound attenuation system is mounted at the top of the first-stage exhaust sound attenuation system, and thefirst-stage exhaust sound attenuation communicates with an exhaust port of the sound insulation box body. According to the supporting noise reduction system for the combustion gas turbine mobile power station, noise produced by the combustion gas turbine during working is reduced, and the working environment is protected.

The invention provides a directional sounding device and method and AR equipment. The directional sounding device comprises a main loudspeaker used for sounding and a silencing loudspeaker; the frequency of sound waves emitted by the silencing loudspeaker is the same as that of sound waves emitted by the main loudspeaker, and the phase of the sound waves emitted by the silencing loudspeaker is opposite to that of the sound waves emitted by the main loudspeaker in the silencing direction. According to the directional sounding device, the main speaker is arranged for sounding, and the silencingloudspeaker is arranged, the silencing loudspeaker points to the silencing direction; the sound attenuation loudspeaker and the main loudspeaker emit sound waves with the same frequency, and the soundattenuation loudspeaker and the main loudspeaker emit sound waves with opposite phases in the sound attenuation direction, so that the sound attenuation loudspeaker in the sound attenuation directioncan weaken or offset the sound waves emitted by the main loudspeaker, and then sound is emitted only in the specified direction to realize directional sound emission.

The invention discloses a ventilation and sound insulation window, which comprises a window, an active noise reduction ventilator is arranged on the window, the active noise reduction ventilator includes a ventilation channel, and a high frequency noise reduction device and a low frequency noise reduction device are arranged on the ventilation channel , the ventilation channel is provided with a fan for increasing the air circulation rate; the low-frequency muffler device includes a low-frequency muffler chamber, and a sound wave generator is arranged on the low-frequency muffler chamber. It can achieve large-flow ventilation in the room and at the same time reduce the noise introduced from the external environment; especially the low-frequency noise less than 300Hz that is not easy to attenuate and has strong penetrability can be effectively controlled to reduce low-frequency radiation noise; when the window is closed, the window as a whole The sound insulation is 35‑40dB, reaching the level 4 sound insulation performance of building doors and windows (GB/T8485‑2000).

The invention discloses a sound insulation and noise reduction method and device for an MVR energy saving vaporization system. A lobed rotor compressor is subjected to sound insulation and noise reduction through a sound insulation cover formed by combining reinforcing ribs, a sound insulation layer, a damping layer and a sound absorption layer, and natural negative pressure heat dissipation is conducted on the sound insulation cover; noise in the sound insulation cover is absorbed through a sound absorption layer of a composite sound absorption and insulation steel plate at first and then secondarily absorbed through a damping layer of the composite sound absorption and insulation steel plate, and after being insulated and weakened, the noise enters a silencer to be subjected to sound attenuation and then is emitted out of a room; a combined heat preservation sound insulation noise reduction material composed of rock wool, a damping material body, a sound-proof felt and an aluminum sheet is applied to a horizontal heat exchanger so that sound reflection can be reduced, that is, reverberation in the sound space can be avoided, and the strength of pipeline vibration radiating outwards is reduced, vibration produced due to the fact that a pipeline is rubbed by gas is inhibited, the situation that a large amount of sound energy is consumed is avoided, and the noise level is decreased; and meanwhile, the influence of inhibiting and weakening resonance and being consistent with response is achieved. According to the sound insulation and noise reduction method and device for the MVR energy saving vaporization system, the noise which is more than three meters away from the device is reduced to 70 dB or less from 110 dB, and plant boundary noise is reduced to 60 dB or less.

The invention relates to a sound attenuation and noise reduction device applied to an air duct. The sound attenuation and noise reduction device includes a flexible joint and a muffler. Flange piecesare arranged at both ends of the flexible joint and the muffler. A pipe at the original air duct is cut and removed, and the flange pieces are installed at pipe orifices by welding. The flange piece at one end of the flexible joint is connected with the flange piece on the end part of the pipe on one side, and the flange piece at the other end of the flexible joint is connected with the flange piece at one end of the muffler. The flange piece at the other end of the muffler is connected with the flange piece on the end part of the pipe on the other side. The sound attenuation and noise reduction device can realize arbitrary combination, disassembly and installation. Meanwhile, the sound attenuation and noise reduction device can be quickly connected and installed with the pipes at any desired position in an original pipeline. Through the installation of the sound attenuation and noise reduction device in the middle of the existing pipe, the impact of vibration generated during the operation of the air duct on existing surrounding structures can be efficiently and safely reduced, the decibel value of noise generated during the operation is reduced, and it is ensured that the factoryboundary noise meets the standard.

The invention discloses a ceiling type indoor air purifier. The air purifier structurally comprises an LED lamp, an air outlet, a display screen, a telescopic rod, a connecting plate, a noise reduction device, a sweeping device, a primary filter screen, an HEPA efficient filter screen, an activated carbon filter screen and a machine body. According to the invention, when purification is carried out after improvement, vibration generated by air purification is reduced through cooperation of the protection damping blocks and the damping springs, most of generated noise is efficiently blocked through the silencing net plate and the sound insulation net plate auxiliary silencing cover, sound generated by operation of the air purifier is eliminated, and the use effect of the air purifier is improved; after air is purified, the brush is driven by the sliding block to rotate, dust particles on the filter screen are swept, then the dust suction piece is used in cooperation with blades for dustsuction treatment, swept dust is sucked into a dust collection cavity through a connector, dust in the air purifier is removed, and the practicability of the air purifier is improved.

The invention discloses a sound attenuation plate capable of absorbing noise. The sound attenuation plate comprises a plate body. Sound attenuation holes are formed in the plate body and comprise sound wave inlets and sound wave outlets which are connected with the sound wave inlets and have large cross sections. The sound wave inlets are located in rims of the sound wave outlets. Sound wave baffles which are identical with the sound wave outlets in terms of shape and size are arranged at the sound wave outlets and arranged on the edges of the sound wave outlets through columns. When noise waves enter the sound wave inlets, the noise waves are compressed by the walls of the sound wave inlets. When the sound waves enter the sound wave outlets, the sound waves rapidly expand, the majority of the sound wave energy of noise is converted into heat energy, the rest of the noise waves are emitted from exit places of the sound wave outlets and encounter the sound wave baffles which are arranged by facing the sound wave outlets. The remaining sound waves are rebounded to the sound wave outlets and coincide with the rest of the noise sound waves emitted from the sound wave outlets. The sound waves which are identical with frequencies and adverse in phases are counteracted, so that the noise is thoroughly eliminated.

A sound attenuating baffle device has a baffle casing supported within a duct such that a boundary wall of the baffle device is oriented in the flow direction from the leading end to the trailing end of the baffle casing. The baffle casing includes a sound attenuating structure therein, and a trailing member protruding outwardly beyond the trailing end of the baffle casing towards a free trailing edge of the trailing member which is non-linear in profile. As compared to a continuous, straight trailing edge as found on most silencer outlets, a non-linear profile, for example a V-shaped or saw-toothed edge, improves the flow distribution along the height of the baffle or perimeter of the centerbody. The distribution of airflow across the resulting extended tail edge represents an improvement in the flow recovery.

The invention provides a double-wall spiral hush pipe and relates to a plastic drain pipe, and particularly relates to a drain pipe capable of sound muffling. The double-wall spiral sound muffling pipe aims to overcome the defect that an existing drain pipe is loud in noise and provide a drain pipeline simple in structure and capable of sound muffling and sound insulating. The double-wall spiral hush pipe comprises a pipe body and is characterized in that the pipeline wall is in a connection and double-layer structure, gapped through holes are evenly formed between the inner wall and the outer wall at intervals, protruding river diversion ribs are evenly arranged along the inner pipeline wall. The double-wall spiral hush pipe mainly applies to a modern construction drainage system.

The invention provides a closed tunnel structure sound barrier for overcoming defects existing in the prior art. The whole sound barrier is easy and rapid to install. By adopting a ventilation and noise reduction window shade, the wind pressure can be lowered, and the influence caused by noise on surroundings when a train passes can be lowered to the maximum extent; by adopting the technical scheme, the closed tunnel structure sound barrier comprises a steel support, a sound barrier unit, a laminated glass noise reduction barrier, an acrylic plate noise reduction barrier and a ventilation and noise reduction window shade, and the closed tunnel sound barrier is composed of a U-shaped structure formed by fixedly connecting the steel support, the sound barrier unit, the laminated glass noise reduction barrier, the acrylic plate noise reduction barrier and the ventilation and noise reduction window shade and a track foundation. The closed tunnel structure sound barrier is widely applied to the field of railroad bridges.

The invention relates to a compound broadband muffler with a multi-layer structure. The compound broadband muffler comprises a shell and a central pipe coaxially arranged in the shell, a closed muffling cavity is formed between the central pipe and the shell, one or more partition plates which divide the muffling cavity into two or more independent spaces are arranged in the muffling cavity, a plurality of muffling holes which communicate with the independent spaces are formed in the central pipe, and air holes are formed in the partition plates between the independent spaces which not communicate with the central pipe through the muffling holes and the adjacent independent spaces. Compared with the prior art, according to the compound broadband muffler, holes are formed in the partition plates, a multi-layer compound porous resonant cavity is formed, and a compound resonant cavity with a plurality of cavities in the structure is formed; and the impedance of the multi-layer resonant structure is utilized to generate the reflection of sound wave for muffling, from the acoustic point of view, the compound broadband muffler is composed of a porous tube resonant cavity and the multi-layer compound porous resonant cavity, the better muffling effect is achieved, and the noise with a wider frequency can be eliminated.

The invention discloses an intelligent noise reduction suspended ceiling. The intelligent noise reduction suspended ceiling comprises a keel frame, a suspended ceiling plate, a sound absorption layerand an active noise reduction device, wherein the keel frame is suspended at the layer top through a hanger; the suspended ceiling plate is arranged on the keel frame and is used for being matched with the layer top to form a silencing cavity; the sound absorption layer is arranged on the suspended ceiling plate and used for absorbing noise; the active noise reduction device is arranged in the silencing cavity and comprises a pickup module, a sound production module and a master control module, the master control module is electrically connected with the pickup module and the sound productionmodule, the master control module is used for picking up noise in the silencing cavity through the pickup module and controlling the sound production module to send out anti-noise with equal noise amplitude and opposite phase when the noise is higher than a preset value. The intelligent noise reduction suspended ceiling provided by the technical scheme of the invention has the advantages of strongnoise reduction capability, energy conservation and high efficiency.

The invention discloses a shock absorption and noise reduction device for an air compressor, and relates to the technical field of air compressors. The device comprises a device body, wherein the device body comprises an outer shell, an inner shell located in the outer shell and a top plate located at the top of the outer shell; a supporting plate is slidably connected into the inner shell; an air compressor is fixed to the top of the supporting plate; telescopic columns are fixed to the four corners of the bottom of the supporting plate; an arc-shaped rubber plate is arranged below the supporting plate; the two sides of the bottom of the rubber plate are slidably connected with chutes in the two sides of the inner bottom wall of the inner shell through sliding mechanisms correspondingly; clamping mechanisms are symmetrically arranged at the two sides of the air compressor; a first adjusting mechanism and a second adjusting mechanism are arranged on the clamping mechanisms; a first acoustical board and a second acoustical board are fixed to the top of the inner shell; sound absorption cotton is filled between the first acoustical board and the second acoustical board; and a vacuum cavity is formed between the second acoustical board and the top plate. The defects in the prior art are overcome, the air compressor is not prone to shaking, and the shock absorption and noise reduction effects are good.

The invention discloses a sound insulation type oil immersed transformer which comprises a base, wherein a device box is arranged at the top of the base, an oil tank is arranged at the top of the device box, silencing boxes are arranged on the two sides of the oil tank, a mounting plate is arranged in the oil tank, an iron core is arranged at the top of the mounting plate, a winding is arranged on the outer side of the iron core, and the bottom of the oil conservator is communicated with an oil pipe penetrating into the oil tank. By means of the linkage mechanism, multiple sets of silencing cotton can move up and down back and forth in a staggered mode, due to the fact that the multiple sets of apertures are formed in the multiple sets of silencing cotton, when the silencing cotton moves up and down, the multiple sets of apertures are continuously staggered, and when noise is spread into the silencing cotton, sound waves can be intricate when penetrating through the apertures, due to viscous resistance of air and continuous vibration friction between the air and the hole wall, most sound energy can be converted into heat energy to be absorbed, and the silencing effect is better.