CN101189415A - Air intake muffler - Google Patents

Abstract

An air intake silencer (10) placed at the inlet of an air handling system includes: a pressurized housing (20) having an inlet end (23) for receiving air and an outlet end (24) for discharging air; two sound insulation panels (28) relatively isolated within the housing, which, together with the housing, define an inlet chamber (30), a central chamber (32), and an outlet chamber (34); and a plurality of tubular components (36) supported by the sound insulation panels (28), each tubular component including a perforated core (40) and sound dissipating fibers (42) wound around the core, wherein air flows into the inlet chamber, passes through the plurality of tubular components into the outlet chamber, and is discharged from the outlet chamber through the outlet.

Description

Air intake muffler

References to other applications

This application claims priority under Title 35, Section 119, of the United States Patent Code to Provisional Patent Application No. 60/687,739, filed June 6, 2005, which is hereby incorporated by reference.

technical field

The present invention relates to an air intake silencer for attenuating the noise of air flowing into an air handling system, such as an air compressor or blower.

Background technique

Air handling systems, such as air compressors or blowers, involve drawing in air from the interface environment. Air in motion, when it reaches the inlet of an air handling system, is subject to changes in air pressure due to the air's interaction with stationary or moving objects. Pressure changes in air manifests, such as sounds, accompanied by annoying or unwanted sounds are broadly defined as noise. Sound propagates at a certain speed through air, other gases and the surrounding medium and reaches the receiver from the wave source in the form of pressure waves. Most sounds at the air inlet of an air compressor are the result of complex interactions between the air and obstacles in its path and are made up of multiple frequencies.

Existing techniques for attempting noise attenuation in industrial air compressor intakes include the use of acoustically lined ducts. Such acoustically lined tubes are typically placed in front of the air intake filter due to the tendency of the acoustic material within the tube to dislodge. The air intake filter thus prevents any shedding of acoustic material from entering the compressor. One disadvantage of this method is that it makes the distance between the liner pipe and the air compressor longer, which further increases the noise and leakage at the connecting pipe and hose. Since noise leaks from the source, noise suppression by effective and economical means becomes quite difficult. Other devices that suppress or prevent further transmission of noise to the surrounding environment include barriers, such as free standing walls and shielding structures. Barriers are characterized by high transmission loss and high absorbing interfaces, and are effective at attenuating high-frequency and short-wave noise. Generally speaking, the physical size of the acoustic barrier should be at least three times the wavelength of the main frequency of the noise. For relatively low-frequency, relatively long-wavelength noise, the size and cost of the acoustic barrier becomes critical. Acoustic shields are used when greater attenuation of noise leakage from the air compressor inlet is required. Typical acoustic shields consist of relatively high transmission loss and high adsorption internal panels and can be placed directly at the source of the noise. Acoustic shields, for the same reasons as the mentioned acoustic barriers, can be relatively large in size and cost. Acoustic enclosures, which are supposed to be airtight to reduce internal noise radiation to the external environment, can also cause heat retention problems, complicating the design of acoustic enclosures and increasing their cost by necessitating cooling systems and specific ventilation systems .

Contents of the invention

In one embodiment, the present invention provides an improved, cost-effective air intake muffler that can be used as a noise attenuation device and can be placed immediately downstream of an air intake filter and directly and The air inlet of the air handling system is connected. In addition, the muffling device offers the least resistance to the passage of air therethrough, thereby providing the downstream air handling system with the required capacity commensurate with its rated performance. Further, the position of the material of the noise reduction device is fixed, and it will not fall off freely under the action of shear and pressure of the air flow.

In one embodiment, an air inlet muffler at the inlet of an air handling system includes a plenum enclosure having an inlet port for receiving filtered air; Together, define an inlet chamber, a central chamber, and a discharge chamber; a plurality of tubular members, which are disposed primarily within the central chamber, each tubular member comprising an end face supported by a baffle, a perforated stainless steel core and a wound Sound dissipating fibers on the core. Filtered air flows into the inlet chamber, undergoes reflection and pressure equalization at the inlet chamber, passes through a plurality of tubular members from the inlet chamber to the discharge chamber, undergoes reflection and pressure equalization at the discharge chamber, and passes through the outlet of the housing Drain from the discharge chamber.

Other features and advantages of the present invention will be apparent to those skilled in the art upon review of the following detailed description, claims and drawings.

Description of drawings

Fig. 1 is a specific embodiment of the air inlet muffler device in the air compression system, wherein, the muffler device is fixed on the downstream side of the air inlet filter and the upstream side of the air compressor;

Fig. 2 is the perspective view of an embodiment of the air intake muffler device;

Fig. 3 is a sectional view of an embodiment of the air intake muffler device shown in Fig. 2;

Fig. 4 is a diagrammatic view of a removable device of the air intake muffler device shown in Fig. 2;

Figure 5(a) and (b) are perspective views of perforated tubular members wound by fibers;

Figure 6 is a diagrammatic view of an acoustic panel.

Detailed ways

Before describing any embodiments of the present invention in detail, it should be understood that the present invention is not limited to the detailed description in this application to the configuration and structure of elements described below or shown in the figures below. The invention is capable of other embodiments and of embodiments in which it is applied or carried out in different ways. It is also to be understood that, for the purposes of description, the phraseology and terminology employed herein should not be taken as limiting. "Includes", "comprises", "has" and similar conjugates thereof mean the inclusion of the subsequently listed item and equals to the appended item. The order recited in any method claims does not imply that the steps or actions presented must be performed in that order unless specifically and clearly stated in that order.

FIG. 1 shows a preferred configuration of an air inlet muffler device 10 for use in an air handling system, such as an air compression system 12 . In particular, the air intake muffler 10 is installed on the downstream side of the air intake filter 14 and on the upstream side of the air compressor 18 . The air is filtered as it flows into the air inlet filter 14, passes through the air inlet muffler 10, to the duct 16, and then enters the air compressor 18 where the air passes through one or more stages of being compressed before being delivered to the compressor type air management system (not shown).

Referring to FIGS. 2 and 3 , the air inlet muffler 10 includes a high pressure housing 20 that receives filtered air at an inlet port 22 . Flange 21 at inlet end 22 allows for easier mounting of intake air muffler 10 to intake air filter 14 . Further, the bracket 19 is used to install the air inlet muffler device 10 on a closet or housing (not shown) of the air compression system 12 , such as a housing for an electronic control unit of the system 12 . The air flows out through the air intake muffler 10 to the outlet 24 of the connecting pipe 16 . In a preferred embodiment, outlet 24 is located at side 26 in housing 20 rather than on the side of the housing opposite inlet port 22 . As described below, the air intake muffler 10 can be placed on the downstream side of the air intake filter 14 because the air intake muffler 10 preferably includes a material that does not easily fall off and flow into the air handling system located on the downstream side.

Referring to Figures 3, 4, 6, in one embodiment, the air inlet muffler 10 includes two baffles 28 isolated from each other in the housing 20, which, together with the housing 20, define an inlet chamber 30 and a central Chamber 32 and exhaust chamber 34 . Preferably, the baffles 28 are arranged parallel to each other in the housing 20 . In other embodiments, it is conceivable to define more than one central chamber 32 with additional baffles. Tubular members 36 for sound dissipation are supported by acoustic panels 28 such that each tubular member 36 is located substantially within central chamber 32 . In detail, the baffle 28 includes a hole 29 through which the end of the tubular member can be inserted or supported. The tubular member 36 and the baffle 28 together form a subassembly 38 as shown in FIG. 4 which can be easily inserted into or removed from the housing 20 .

As shown in Figures 5(a)-(b), each tubular member 36 includes a perforated core 40 around which sound dissipative fibers 42 are wound. In one embodiment the tubular member is a water filtration device, such as from Johnson Filtration Products. The perforated core 40 may be stainless steel. Further, in one embodiment, the area of the outer surface of the core is perforated to approximately 30% of the area of the outer surface of a uniform unperforated core. The core may consist of other materials such as fine wire mesh. Further, in one embodiment, the fibers are cotton, although in other embodiments, the fibers may be one or more other fibers, such as fiberglass, nylon, or polyester. Preferably, the sound dissipating fibers cannot shed and flow into the compression system 12 on the downstream side.

In the exemplary embodiment, inlet chamber 30 and outlet chamber 34 act as reactive plenums. Air filtered from the air inlet filter 14 flows into the inlet chamber 30 . The air in the inlet chamber undergoes reflections so that pressure changes in the inlet chamber are balanced to some extent. Air then passes from the inlet chamber 30 , through each of the plurality of tubular members 36 , and into the outlet chamber 34 . The sound in the central chamber 32 is attenuated by the sound dissipation effect of the fibers 42 . The air in the discharge chamber undergoes reflections so that pressure changes in the discharge chamber are balanced to some extent. Air is exhausted from exhaust chamber 34 through outlet 24 .

In other embodiments, the inlet chamber 30 and/or the outlet chamber 34 may also be lined with an adsorbent (dissipative) material so that sound is also dissipated in these chambers.

Various features and advantages of the invention are set forth in the following claims.

Claims (20)

1. An air intake muffler placed at the inlet of the air handling system, comprising: a plenum enclosure having an inlet port for receiving air and an outlet port for exhausting air; at least two relatively isolated baffles in the housing which together with the housing define an inlet chamber, a central chamber and an exhaust chamber; a plurality of tubular members supported by acoustic panels, each tubular member comprising a perforated core and sound dissipative fibers wound around the core, wherein, Air flows into the inlet chamber, enters the outlet chamber through the plurality of tubular members, and exits from the outlet chamber through the outlet. 2. The air intake muffler device of claim 1, wherein the core is stainless steel. 3. The air intake muffler device of claim 1, wherein the wrapping fibers are cotton. 4. The air intake muffler device of claim 1, wherein the tubular member is a water filtration device. 5. The air intake muffler device of claim 1, wherein the housing is generally box-shaped. 6. The air intake muffler device of claim 1, wherein the baffle panels are identical. 7. The air intake muffler assembly of claim 1, wherein the baffle and tubular member comprise removable subassemblies. 8. The air intake muffler of claim 1, wherein the perforated area on the outer surface of the core is about 30% of the outer surface of the same core that is not perforated. 9. The air intake muffler device of claim 1, further comprising an outwardly extending flange at the inlet end, wherein the flange is used to secure the device to the air intake filter. 10. The air intake muffler device of claim 9, wherein a duct connects the outlet to the air handling system. 11. The air intake muffler device of claim 1, wherein the tubular members are all substantially parallel to each other. 12. An air intake muffler device placed at the inlet of an air handling system, the air intake muffler device comprising: a plenum enclosure having an inlet port for receiving filtered air; at least two relatively isolated acoustic panels which, together with the housing, define an inlet chamber, a central chamber and an exhaust chamber; and a plurality of tubular members disposed substantially within the central chamber, each tubular member comprising an end face supported by a baffle, a perforated stainless steel core and sound dissipative fibers wound around the core, wherein filtered air flows into the inlet chamber and undergoes reflection and pressure equalization at the inlet chamber, passes from the inlet chamber through a plurality of tubular members to the discharge chamber, experiences reflection and pressure balance at the discharge chamber, and Exhaust from the discharge chamber through the outlet of the housing. 13. The air intake muffler device of claim 12, wherein the tubular member is a water filtration device. 14. The air intake muffler device of claim 12, wherein the housing is generally box-shaped. 15. The air intake muffler device of claim 12, wherein there are two identical baffles. 16. The air intake muffler assembly of claim 12, wherein the baffle and tubular member comprise removable subassemblies. 17. The air intake muffler device of claim 12, wherein the perforated area on the outer surface of the core is about 30% of the outer surface of the same core that is not perforated. 18. The air intake muffler device of claim 12, further comprising a flange extending outwardly at the end having the inlet, wherein the flange is used to secure the device to the air intake filter. 19. The air intake muffler device of claim 18, wherein a pipe connects the outlet to the air compressor. 20. The air intake muffler device of claim 12, wherein the tubular members are all substantially parallel to each other.

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