ALUPOR™ performs exceptionally well alongside sintered materials for exhaust noise silencing. Moreover, silencers made of porous aluminum function perfectly under cryogenic temperatures maintaining their strength properties. Exhaust noise can occur in various technological processes involving pneumatic and compressor equipment. Technological equipment that assumes gas discharge have to be equipped with silencers to protect the environment and production personnel from the harmful effects of noise. Currently, the company offers several series of commercially produced silencers.

• GR-SW series - Thread silencers
• GR-SW-HP series - High pressure silencers
• M series - Special silencers for pneumatic motors / engines / screwdrivers

• Increased strength and durability compared to silencers made of sintered powders
• Resistance to cyclic and vibration loads
• Resistance to contaminants — maintains flow capacity for extended periods even in dusty air
• High dirt-holding capacity due to unique structure
• Fully controlled and stable structural parameters
• Durability: maximum pressure differential up to 50 atm (under normal conditions)
• Any sizes and configurations available
• Parts combining solid and porous sections in a single product
• Thread cutting possible on both solid metal and porous sections
• Low weight - only plastic is a competitor
• Service life exceeding 5 years
• Environmentally friendly — material can be recycled as aluminum scrap

• Icing (fair for any porous silencer): when designing silencers, it should be considered that the discharged medium is throttling through the porous structure. Its temperature may drop below the crystallization point of the water. Ice formation on the silencer can reduce or completely block the flow. In such conditions, heating is required.
• On large silencers, noise may be generated inside the silencer itself: it is necessary to provide additional distribution elements made of coarse-porous material at the outlet of the pipe for preliminary jet breaking.

FLOW PARAMETERS

STRUCTURE PROPERTIES

More details on mechanical properties of ALUPOR™ see "Properties" page.

MECHANICAL PROPERTIES

More details on mechanical properties of ALUPOR™ see "Properties" page.

• Maximum dimensions of the final flat part: 850 × 650 × 150 mm
• Maximum dimensions of the cylinder part: ø410, length is not limited
• Minimum plate thickness:
  • 3 mm for parts up to 300 mm
  • 5 mm for parts up to 500 mm
  • 8 mm for parts over 500 mm
• Final product weight: up to 150 kg
• Manufacturing method: casting with vacuum impregnation of NaCl (see here...)
• Threading available for both solid metal and porous sections

Parts with Solid Metal Sections (SMS) are a significant advantage of our technology because we can do fastening elements on solid section. Possible options for manufacturing parts with solid metal sections are presented below.

Without solid section

Solid end face

Solid flange

Seal slots for O-ring

Tread & Hex-nut

Tread & Seal slots 

Modular Mufflers

The image shows a special solution for large-volume steam discharge: a steel casing containing a cylindrical porous element with anti-icing electric heating incide.

Anodizing and Oxidation

To enhance corrosion resistance it is possible to perform anodizing or micro-arc oxidation treatment on the entire internal surface of pores. 

Noise is generated during exhaust of compressed air from pneumatic units due to flow turbulence at zones between jet and the external environment. Turbulent compressed air vortices excite acoustic vibrations in the surrounding air medium. A silencer made of ALUPOR™ porous material distributes the turbulent flow from the pipe over the filtering area of the silencer and divides it into many small streams with more favorable hydraulic characteristics, thereby reducing the sound power level. The theory of aeroacoustics is quite complex. Here we will provide the most general and simplest formulations and references for following deeper understanding.