171results about How to "Improve the noise reduction effect" patented technology

The utility model provides a broadband silencer and an engine air inlet system. The broadband silencer comprises an air inlet pipe, an air outlet pipe, a silencer shell connected between the air inlet pipe and the air outlet pipe, and a resonance sound absorption structure arranged in the silencer shell. The resonance sound absorption structure is made of an elastic vibration material and is configured to be tubular; the resonance sound absorption structure is connected between the air inlet pipe and the air outlet pipe and forms an air inlet channel together with the air inlet pipe and the air outlet pipe. The inner diameter of the silencer shell is larger than the outer diameter of the resonance sound absorption structure, and a silencing cavity is formed between the silencer shell and the resonance sound absorption structure. According to the broadband silencer, elastic vibration of the resonance sound absorption structure enables the silencing cavity to form a resonance cavity, energy of noise is converted into vibration kinetic energy, and therefore the silencing performance of the broadband silencer can be improved.

The utility model discloses a pressure regulating silencer with a deslagging function, which comprises a silencing pipe, a pressure regulating sleeve sleeved on the silencing pipe and a silencing outer sleeve sleeved outside the pressure regulating sleeve, a silencing chamber is formed between the silencing pipe and the silencing outer sleeve, a deslagging silencing hole communicated with the silencing chamber is arranged on the silencing pipe, and a deslagging hole is arranged on the silencing outer sleeve. The residue discharging holes are formed in the silencing outer sleeve, so that independent residue discharging paths are formed among the residue discharging silencing holes in the silencing pipe, the silencing chamber between the silencing pipe and the silencing outer sleeve and the residue discharging holes in the silencing outer sleeve, and residues do not need to enter the nail fixing device any more. The nail fixing device effectively prevents the residues from entering the nail fixing device to cause corrosion, jamming and other damage to key components (such as a firing pin assembly), greatly prolongs the service life of related equipment components, reduces the maintenance frequency and cost caused by component damage, does not need to disassemble and assemble the nail fixing device main body to clean the residues in the nail fixing device, and improves the working efficiency. And the overall reliability and stability of the equipment are improved.

The high-position air inlet channel comprises an air inlet channel shell, an air inlet and an air outlet are formed in the air inlet channel shell, the air inlet and the air outlet are communicated to form an airflow channel, and the air inlet and the air outlet face different directions; the channel structure comprises a first-section channel close to the air inlet and a rear-section channel close to the air outlet, the air inlet is formed in one end of the first-section channel, the other end of the first-section channel is communicated with one end of the rear-section channel, the air outlet is formed in the other end of the rear-section channel, and the first-section channel is divided into a plurality of side-by-side channels in the airflow circulation direction; wherein the plurality of channels are suitable for generating reflected sound waves to counteract sound waves transmitted from the rear-section channel to the first-section channel. By the adoption of the high-position air inlet channel, the silencing function of the air inlet of the high-position air inlet channel can be achieved, weight cost increase caused by an external connection structure can be reduced, and the high-position air inlet channel is more attractive.

The invention relates to the technical field of visual image detection based on deep learning, and particularly discloses a conveyor belt deviation detection method and an improved yolov5 network model, and the model comprises carrier roller detection processing and belt area segmentation processing; the method comprises establishing a model; training data by using an improved yolov5 network model; when the conveyor belt is subjected to deviation detection, a camera acquires a detection image, and the called improved yolov5 network model is processed and input; the area of the carrier roller is calculated through carrier roller detection processing, and whether the area exceeds a set threshold value or not is judged; carrying out belt region segmentation processing for edge extraction, and judging whether a detection straight line deviates from a threshold value of a set straight line or not through Hough straight line detection; when the two judgment results are both yes, deviation is judged, and an alarm is given; and when one or two judgment results are negative, the steps are performed again. The method is a novel method for detecting belt deviation based on deep learning, and a more accurate detection result can be obtained.

The utility model relates to an oilless compressor which comprises a crankcase, the crankcase is connected with an air cylinder box, a crankshaft is arranged in the crankcase and connected with an air cylinder through a connecting rod, the air cylinder reciprocates in the air cylinder box, balancing weights are arranged at the two ends of the crankshaft, a transmission shaft is fixedly connected to the rotating center of the balancing weight on one side, and a transmission shaft is fixedly connected to the rotating center of the balancing weight on the other side. The transmission shaft penetrates through the bearing box to be connected with the transmission wheel, the bearing box is connected with the crankcase, the transmission shaft is connected with the bearing box through a bearing, and the shaft diameter of the transmission shaft is not smaller than one third of the sectional area of the balancing weight. According to the oilless compressor, the balancing weights are arranged at the two ends of the crankshaft, the rotating center of the balancing weight on one side is fixedly connected with the transmission shaft, the crankshaft is supported only through the transmission shaft, vibration of the crankshaft is completely transmitted to the transmission shaft, the crankshaft is not connected with the crankcase, and vibration of the crankshaft cannot be transmitted to the crankcase; vibration of the crankcase can be reduced, and therefore vibration noise is reduced.

The utility model relates to the technical field of silencer devices, in particular to an efficient fan silencer, which comprises a fan silencer main body, a silencing core part of the fan silencer main body is as follows: a common limit type resistance-limiting composite wide interesting belt silencing body is arranged in the fan silencer main body and is formed by compounding a resonator and a resistive sound absorption ring made of resistive sound absorption materials, the cavity depth is 15cm, the agricultural thickness is 25mm, and the inner side of the fan silencer main body is provided with a plurality of through holes; the sound absorption coefficients of resonators with the punching rates of 06%, 1%, 12% and 2% within the frequency range of 125-400 HZ are all larger than 07, the resonance silencing body is matched with a glass wool integrated body (the density is 2 skgm, and the surface glass is combined with a steel plate net), so that the sound absorption coefficient of the resonance silencing body within the broadband range of 125-8000 Hz reaches up to more than 07, and the sound absorption coefficient of the resonance silencing body within the broadband range of 125-8000 Hz reaches up to more than 07. Meanwhile, the silencer made of a plurality of common-limit type limited-resistance composite wide interesting belt silencing body structures is adopted, and a good silencing effect can be obtained within a wide frequency range by selecting the combination of different plate thicknesses, perforation L diameters, different cavity depths behind the silencing perforated plates and the like.

The utility model belongs to the technical field of gas film buildings, and particularly relates to a gas film structure capable of effectively reducing sound focusing in a gas film, which comprises a gas film, a steel wire rope, a sound-absorbing plate and a reinforcing rope, a plurality of hanging rings are arranged at the top of the gas film, one end of the steel wire rope is connected with the hanging rings in a hanging manner, and the other end of the steel wire rope is connected with the sound-absorbing plate in a hanging manner. The adjacent sound absorption plates are arranged in an up-down staggered mode, and the reinforcing rope is connected with a plurality of steel wire ropes in a tying and hanging mode. The plurality of sound-absorbing plates which are arranged in an up-down staggered manner can enable part of sound waves reflected by the upper sound-absorbing plate to be reflected by the lower sound-absorbing plate again, so that the sound waves are absorbed for multiple times, and the sound attenuation effect is effectively improved; a plurality of steel wire ropes can be connected into a whole through the reinforcing ropes, and the hanging stability of the acoustic board is improved.

The invention relates to the field of propellers or rotors for airplanes, in particular to a bionic curved zigzag ducted rotor based on owl wings. A bionic curved zigzag ducted rotor wing based on an owl wing comprises a ducted body (1), a support (2) and a rotating shaft (3), the outer end of the support (2) is fixed on the inner side wall of the ducted body (1), the rotating shaft (3) is rotatably arranged at the center of the support (2), the bionic curved zigzag ducted rotor wing is characterized by further comprising at least two rotor wings (4), the rear ends of the rotor wings (4) are fixed on the rotating shaft (3), and the rotor wings (4) are evenly distributed around the rotating shaft (3). Namely, the connecting lines of the outer end points of all the rotor wings (4) form a line segment or a regular polygon with the rotating shaft (3) as the center, gaps are reserved between the front ends of the rotor wings (4) and the inner side wall of the duct body (1), and sawteeth (41) are arranged on the rear edges of the rotor wings (4). The pneumatic performance is excellent, and noise is reduced.

The invention relates to the field of portable heat dissipation, in particular to a neck-hanging fan which comprises a fan, a ventilation channel, a first air inlet and a first air outlet, the first air inlet and the first air outlet are communicated with the ventilation channel, and the fan is arranged in the ventilation channel. The fan runs, air flow penetrating through the ventilation channel is formed between the first air inlet and the first air outlet, and the direction of the rotating center axis of the fan is consistent with the direction of the air flow; at least two silencing devices are arranged in the ventilation channel, at least one silencing device is arranged between the first air inlet and the draught fan, and at least the other silencing device is arranged between the draught fan and the first air outlet. The neck-hanging fan can achieve the effects of high wind speed and low noise, and can effectively reduce the influence of high-frequency noise on a user so as to improve the user experience.

The invention relates to the technical field of air conditioning equipment, in particular to an air treatment air cabinet. The air handling air cabinet comprises a shell, an air duct is arranged in the shell, and the air duct comprises an air return channel, a heat exchange channel and an air supply channel which are sequentially arranged in the air flow direction; the air return channel and the air supply channel are arranged side by side in parallel, so that the air channel is of a U-shaped structure. The heat exchanger comprises a filter module, a heat exchange module, a fan module and a silencing module. According to the embodiment of the invention, the air duct is arranged to be of the U-shaped structure, so that the flowing path of air in the air cabinet is more reasonable, the air flowing resistance is reduced to a certain extent, and the air treatment efficiency is improved. Due to the fact that the filtering module is mainly installed in the air return channel, the space occupied by the filtering module is sufficient, under the condition of the same air passing area, the filtering module can be thicker, the whole unfolded filtering area is larger, the service life is longer, and the replacement period of the filtering module is greatly prolonged.

The utility model relates to a combined splash-proof device of a high-level water-collecting mechanical draft cooling tower, which comprises a water-collecting tank and a water-collecting inclined plate, the water-collecting inclined plate is obliquely arranged, the water-collecting tank is arranged below the lower end of the water-collecting inclined plate, the included angle between the water-collecting inclined plate and the horizontal plane is 45-55 degrees, a splash-proof filler is further arranged on the water-collecting inclined plate, and the splash-proof filler is arranged on the lower end of the water-collecting inclined plate. The splash-proof filler is obliquely and upwards placed on the upper surface of the water collecting inclined plate from the lower end of the water collecting inclined plate, one end of the splash-proof filler is aligned to the lower end of the water collecting inclined plate, and the length H2 of the splash-proof filler is two thirds of the length H1 of the water collecting inclined plate in the inclination direction from the lower end to the high end of the water collecting inclined plate. The utility model mainly aims to provide the combined type splash-proof device of the high-level water collecting mechanical ventilation cooling tower, which has the functions of silencing and reducing noise, and is remarkable in splash-proof effect and good in economical efficiency.

The invention discloses a silencing device for an outlet of a fire-fighting smoke exhaust fan. The silencing device comprises a mounting cylinder and a plurality of components assembled in the mounting cylinder, wherein the components comprise a smoke dust cleaning component, a heat exchange silencing component, a smoke dust collecting tank, an adsorption component and a smoke dust discharging component. The smoke cleaning assembly is located at the top of the mounting cylinder, the heat exchange silencing assembly and the smoke collecting tank are connected to the bottom of the mounting cylinder, the adsorption assembly is connected to the bottom of the heat exchange silencing assembly, and the smoke discharging assembly is connected to the bottom of the smoke collecting tank and located on the inner side of the adsorption assembly. The device forms a closed cold air through cavity, and a smoke outlet is formed in the bottom, so that effective smoke emission is ensured. In addition, the device further comprises a stirring assembly, a conveying assembly and a driving assembly which are connected with the adsorption assembly and the smoke dust discharging assembly respectively. Not only is the silencing effect remarkably improved, but also the functions of smoke cooling, dust removal and toxic and harmful substance treatment are integrated, many problems in the prior art are effectively solved, and a safe, environment-friendly and efficient smoke exhaust silencing device is provided for the field of fire protection and smoke exhaust.

The utility model discloses a pressure regulating sleeve which comprises a sleeve section and a pressing step on the end portion of the sleeve section, the sleeve section is provided with a pressure regulating hole and at least one step ring, and the step ring is provided with a chip removal channel. According to the design, the gap between the silencing outer sleeve and the pressure regulating sleeve of the silencer can be divided into a plurality of chambers through the step rings, the silencing effect is effectively improved, and noise transmission is reduced. And meanwhile, a deslagging channel is optimized, residues are prevented from directly entering the nail fixer main body, the problems of corrosion and jamming of key parts are reduced, the structural stability is enhanced, the equipment reliability is improved, and the service life of the equipment is prolonged. The problems that an existing pressure regulating sleeve is poor in noise reduction effect, and residues damage parts of a nail fixing device are effectively solved.

This utility model discloses a low-resistance, sound-absorbing, enhanced composite fiberglass duct, comprising a duct body and a sound-absorbing inner tube. The duct body includes, from the inside out, a porous aluminum plate layer, a first fiberglass cloth layer, a glass fiber layer, a second fiberglass cloth layer, and an outer protective color steel layer. The surface of the porous aluminum plate layer has multiple equidistantly distributed strip-shaped grooves, and ventilation holes are provided on the inner walls of both sides of the strip-shaped grooves. The sound-absorbing inner tube includes two pairs of upper supports, two pairs of lower supports, a first sound-absorbing aluminum tube, a fiberglass ring, and a second sound-absorbing aluminum tube. By setting the strip-shaped grooves and ventilation holes, the contact area between the airflow and the porous aluminum plate layer can be increased, allowing the glass fiber layer to better absorb sound waves. By setting the sound-absorbing inner tube, sound waves will contact the second and first sound-absorbing aluminum tubes from both the inside and outside sides respectively. Finally, the fiberglass ring can further reduce noise. This utility model effectively improves the sound absorption and noise reduction effect when the wind speed is high or the noise level is high.

The utility model discloses a cooling tower air duct with a noise reduction and flow guide structure, which comprises a mounting seat, a plurality of mounting holes are equidistantly formed in the edge of the top of the mounting seat in a surrounding manner, the top of the mounting seat is fixedly communicated with an air duct body, and a plurality of flow guide plates are fixedly connected onto the inner wall of the air duct body. A first silencing assembly is arranged on the inner wall of the air duct body. The mounting seat, the mounting hole, the air duct body, the guide plate, the first silencing assembly, the first silencing layer, the first sound insulation felt layer, the glass wool layer, the second sound insulation felt layer, the first silencing plate, the first silencing groove, the second silencing assembly, the silencing cover, the second silencing layer, the second silencing plate and the second silencing groove are matched with one another, so that a good silencing effect is achieved; and therefore, the practicability of the cooling tower air duct is greatly improved, and the market demand can be greatly met.

The utility model discloses a decorative plate not prone to deformation, and belongs to the technical field of decorative plates. Aiming at the problem that the existing decorative plate cannot absorb noise and impact, the utility model provides the following technical scheme that the decorative plate comprises a wood plate and a reinforcing layer, and the reinforcing layer is arranged in the wood plate; the bottom of the wooden board is connected with a silencing layer, and the bottom of the silencing layer is connected with a cushioning layer. The sound attenuation layer and the shock absorption layer are installed on the wooden board, the sound attenuation layer is connected to the bottom of the wooden board and is made of flexible rubber materials, when noise in the external environment is conducted into the decorative board, the sound attenuation effect of the decorative board is improved through the air guide holes in the outer surface of the sound attenuation layer, and the shock absorption layer is made of silica gel materials. When the impact force in the external environment is conducted to the interior of the decorative plate, the decorative plate further absorbs the impact force, and then the stability of the decorative plate is improved.

The utility model discloses a square cabin detachable partition, including front board, side plate, roof and a plurality of first L shape pressure bar, a plurality of positioning pin is fixed respectively in first L shape pressure bar, and the front board bottom, side plate bottom and roof rear part are fixed respectively a plurality of locating plate, and the locating sleeve of locating plate middle part is respectively inserted in the front board bottom, side plate bottom and roof rear part, when assembling, the locating sleeve of front board bottom and side plate bottom is respectively inserted on the corresponding positioning pin of first L shape pressure bar on square cabin floor, and the locating sleeve of roof rear part is respectively inserted on the corresponding positioning pin of first L shape pressure bar on rear cabin wall. The utility model guarantees that each board piece can be separately disassembled, and the disassembly is very convenient, and each board piece is light in weight, and the transportation is time -saving and labor -saving, and the work efficiency is high. Each board piece is filled with polyurethane foam, and the heat preservation and sound attenuation effect are good, and the first L shape pressure bar and second L shape pressure bar all paste sponge rubber board, and can play waterproof sealing effect.

The utility model belongs to the technical field of sound barriers, and particularly relates to a composite nonmetal sound barrier unit plate. The non-metal sound barrier unit plate comprises a back plate formed by pouring concrete and a face plate made of ceramic particle sound absorption materials, the back plate and the face plate are connected through a damping deformation layer, and the face plate can float relative to the back plate in a damping mode after being impacted by a load. The sound absorption panel of the non-metal sound barrier unit plate can perform damping floating relative to the back plate, so that the non-metal sound barrier unit plate is more impact-resistant and fatigue-resistant, and has the characteristics of high structural strength, lasting vibration and noise reduction effects and long service life.

The utility model discloses a special silencer for an adsorption type drying machine, and relates to the related technical field of the adsorption type drying machine. The device comprises an exhaust jacket, a bottom end cover, a top end cover and a gas delivery pipe, an installation disc is fixed to the lower portion of the inner wall of the exhaust jacket, the gas delivery pipe is fixed to the center of the top end of the installation disc, spiral blades are fixed to the peripheral side of the gas delivery pipe, the top end cover is fixed to the upper portion of the peripheral side of the gas delivery pipe, and the bottom end cover is fixed to the lower portion of the peripheral side of the exhaust jacket. The top end of the bottom end cover is flush with the top end of the mounting disc. By arranging the exhaust jacket, the bottom end cover, the top end cover and the gas conveying pipe, the problems that the special silencer for the adsorption type drying machine is insufficient in gas-water separation and poor in silencing effect are solved, and the special silencer for the adsorption type drying machine has the advantages that the special silencer for the adsorption type drying machine is more sufficient in gas-water separation and better in silencing effect.

The utility model discloses a silencer which comprises a body, the body is provided with a cavity, the two ends of the cavity are provided with a first communicating nozzle and a second communicating nozzle which are communicated with each other, and the first communicating nozzle and the second communicating nozzle are arranged in a staggered mode. A first inclined partition plate and a second inclined partition plate are arranged in the cavity, the first partition plate is provided with a first communicating groove, the second partition plate is provided with a second communicating groove, and the first communicating groove and the second communicating groove are vertically staggered; the first partition plate and the second partition plate divide the cavity into a first cavity, a second cavity and a third cavity, the first cavity is communicated with the first communication nozzle, the second cavity is located between the first cavity and the third cavity and communicated with the first cavity and the third cavity, and the third cavity is communicated with the second communication nozzle. The propagation path of sound waves in the silencer body is prolonged, the reflection frequency of the sound waves is increased, and finally a better silencing effect is achieved.

The present invention relates to the field of air compressors, and in particular to a portable air compressor, comprising a motor and a chassis arranged at the output end of the motor, a head assembly for compressing air arranged on the chassis, a pressure stabilizing tank arranged on the chassis, the pressure stabilizing tank and the motor arranged on opposite sides of the chassis, and the outer dimensions of the pressure stabilizing tank do not exceed the chassis; the pressure stabilizing tank comprises a side wall and an end cover arranged at the end of the side wall, a cavity is formed between the side wall and the end cover, and the other end of the side wall is sealed and connected to the chassis, so that the cavity becomes an air storage chamber; a mounting portion is arranged on the side wall, and a gas transmission channel connected to the air storage chamber is arranged in the mounting portion, and the input end of the gas transmission channel is connected to the high-pressure end in the head assembly. The present invention is provided with a pressure stabilizing tank at one end of the air compressor, and the outer dimensions of the pressure stabilizing tank do not exceed the chassis, so that it is easy to carry.

The application belongs to the field of acoustics, and discloses a low-frequency and wide-band noise reduction acoustic structure and a design method of the acoustic structure. The acoustic structure comprises a plurality of acoustic structural members and an embedded member. At least one embedded member is arranged in the plurality of acoustic structural members. On the same embedded member, the acoustic structural members in communication with the two open ends of the embedded member are arranged in pairs and jointly form a first unit. The acoustic structural member not in communication with the embedded member is a second unit. The first unit and the second unit are arranged in parallel. Compared with the prior art, when sound waves pass through the acoustic structural members arranged in pairs, the coupling resonance generated in the acoustic structural members can widen the noise reduction frequency band at a certain resonance frequency in the low-frequency range. The added embedded member can generate a new noise reduction frequency band. The weak coupling effect between the parallel units can further widen the noise reduction frequency band. Finally, the low-frequency and wide-band noise reduction effect is achieved.

The invention relates to the technical field of airflow silencing, in particular to an automobile airflow silencer which comprises a shell and a shell air inlet. The connecting pipe is connected to the inner wall of the air inlet of the inner shell in an inserted mode, and a rectangular or round hole communicated with the first inner cavity is formed in the outer wall of the connecting pipe. The air inlet pipe is connected to the inner wall of the air inlet of the shell in an inserted mode, and the air inlet pipe corresponds to the connecting pipe in position. The front end of the air outlet pipe penetrates through the outer shell air outlet and then is inserted into the inner wall of the inner shell air outlet, and a rectangular or circular hole communicated with the interior of the outer shell is formed in the outer wall of the lower end of the air outlet pipe. By improving the automobile airflow silencer, the automobile airflow silencer has the advantages of being reasonable in structural design, rapid in silencing, smooth in exhaust and capable of changing the exhaust sound effect, and therefore the problems and defects in the prior art and equipment are effectively solved.

The utility model discloses a deslagging silencer. The deslagging silencer comprises a silencing pipe, a pressure regulating sleeve, a silencing outer sleeve, a heat insulation sleeve and a heat dissipation deslagging sleeve. A first deslagging silencing gap is formed between the heat dissipation deslagging sleeve and the silencing outer sleeve, a second deslagging silencing gap is formed between the heat insulation sleeve and the heat dissipation deslagging sleeve, a first silencing deslagging opening is formed in the outer wall of the heat insulation sleeve, and a second silencing deslagging opening is formed in the outer wall of the heat dissipation deslagging sleeve. The first deslagging and noise reduction gap and the second deslagging and noise reduction gap are communicated through a third deslagging and noise reduction opening in the heat dissipation and deslagging sleeve, and the first deslagging and noise reduction gap is communicated with a binding channel in the silencing pipe through a deslagging channel. The heat dissipation deslagging sleeve is arranged between the heat insulation sleeve and the silencing outer sleeve, impact and corrosion to the heat insulation sleeve can be reduced, the service life of the heat insulation sleeve is prolonged, the heat insulation performance is enhanced, the silencing effect is enhanced, meanwhile, a traditional deslagging mode is changed, residues are prevented from entering the nail fixing device, and the service life of the nail fixing device is prolonged.

This utility model relates to the field of high-gloss wall panel technology, specifically a crack-resistant high-gloss wall panel, comprising a first substrate board, a second substrate board disposed on one side of the first substrate board, a quick-assembly mechanism disposed on the surfaces of the first and second substrate boards, a crack-resistant mechanism disposed inside the first substrate board, and a sound-dampening mechanism disposed inside the first substrate board. This utility model not only significantly improves the assembly efficiency between the first and second substrate boards during use, making the high-gloss wall panel more convenient for users to operate, but also increases the overall strength of the high-gloss wall panel, making it less prone to cracking and more durable. Furthermore, it reduces noise interference, improving users' sleep quality and quality of life, reducing the impact of noise on the wall structure, and extending the building's lifespan.

The utility model discloses a flange plate with sound attenuation groove, including flange plate, auxiliary mechanism, the top of flange plate is ring array and is equipped with mounting hole, auxiliary mechanism is located at the top of flange plate, and auxiliary mechanism is used for carrying out sound attenuation protection to flange plate, and auxiliary mechanism includes sound absorption cylinder, sound attenuation groove, sound absorption subassembly, and sound absorption cylinder fixedly connected in the top of flange plate, and sound attenuation groove is equipped with in the top of flange plate, and sound absorption subassembly is located inside sound absorption cylinder. The utility model discloses a mutual cooperation of sound absorption cylinder, sound attenuation groove, sound absorption subassembly, heat conduction spare, fixed ring and auxiliary sound attenuation cylinder, and sound absorption subassembly is located inside sound attenuation groove, and sound attenuation groove carries out the absorption to the noise of flange plate, and absorption subassembly carries out sound absorption and sound attenuation operation, and auxiliary sound attenuation cylinder carries out sound absorption operation to fixed ring, is favorable in directly carrying out sound attenuation operation on flange plate, is convenient for improving the sound attenuation effect of flange plate, and is favorable in carrying out heat export protection when sound attenuation.

This invention relates to a low-noise optical module three-temperature testing device, comprising a test box with a test cavity formed inside. An air inlet pipe is connected to the test box and communicates with the test cavity. A first silencing cavity is also formed inside the test box, and a first exhaust channel communicating with the first silencing cavity is provided on the test box. A duct is also connected to the test box, connecting the test cavity and the first silencing cavity. By setting up the first silencing cavity and connecting it to the test cavity via the duct, this invention not only extends the gas flow path within the test box and serves to store airflow, but also significantly increases the gas flow area and the diffuse reflection area and number of reflections within the test box, thereby reducing gas velocity and noise energy, achieving noise reduction. The test cavity-duct-first silencing cavity can form a Venturi effect, resulting in better noise reduction.

The silencer for the marine air conditioner comprises a silencing barrel and an air outlet barrel frame, the air outlet barrel frame is arranged at one end of the silencing barrel, a silencing cotton barrel is arranged on the inner wall of the silencing barrel, a plurality of sets of static silencing inwards-concave pieces are arranged in the silencing cotton barrel at equal intervals, and the silencing cotton barrel is arranged in the silencing cotton barrel. A plurality of static silencing concave pieces are arranged in the silencing cotton barrel, a reflecting cavity is formed between every two adjacent static silencing concave pieces, a movable silencing concave piece is arranged at the position, on one side of each static silencing concave piece, in the silencing cotton barrel, air holes are formed in the center positions of the interiors of the static silencing concave pieces and the movable silencing concave pieces, and a sealing ring is installed on the outer wall of each movable silencing concave piece. According to the silencer for the marine air conditioner, the excellent noise reduction and silencing effect of the silencer for the marine air conditioner is achieved, the size of air noise can be adjusted in a micro mode conveniently, the size of an air outlet can be conveniently and rapidly controlled for air supply, and the convenience of air volume adjustment is improved.

The utility model discloses a noise elimination structure, equipment and light storage system, the noise elimination structure is installed at an air inlet and / or an air outlet, the noise elimination structure comprises an outer frame, a blocking part and a first sound absorption part, the edge of the outer frame is formed by connecting an arc section and a plurality of continuous straight line sections or arc lines and straight line sections in a matched mode, the blocking part comprises a plurality of cavities, and the first sound absorption part comprises a first sound absorption part and a second sound absorption part. The cavity is formed by abutting one end of the first partition plate and / or one end of the second partition plate against the outer frame, the inclination angle of the second partition plate relative to the air inlet and / or the air outlet is larger than or equal to 0 degree and smaller than or equal to 180 degrees, and the first sound absorption part covers the blocking part. According to the technical scheme, noise at the air inlet and / or the air outlet can be reduced, sound leakage and sound pollution are reduced, and normal life and physical and psychological health of residents are facilitated.

The utility model discloses a sound attenuation through-wall pipe for building water supply and drainage, and particularly relates to the technical field of building equipment, the sound attenuation through-wall pipe comprises an outer sleeve, an inner sleeve is arranged in the outer sleeve, the shape of the inner sleeve is a circular pipe, a sound attenuation mechanism is arranged outside the inner sleeve, and the sound attenuation mechanism comprises two damping sleeves sleeved outside the inner sleeve. The two shock absorption sleeves are sleeved with fixing sleeves, silencing cotton is arranged in the shock absorption sleeves and the fixing sleeves, a plurality of clamping grooves are formed in the inner wall of the outer sleeve, sound insulation layers are arranged in the clamping grooves, shock absorbers are arranged on one sides of the fixing sleeves, and one sides of the shock absorbers are connected with the clamping grooves. According to the device, the interior of the pipeline can be silenced, the influence of noise pollution of the drainage pipe on a building is effectively reduced, and the installation stability of the device can be improved.