PCA filtering elements advantages

Metal filtering elements are mounted on the most important equipment or in extreme operational conditions. Filtering elements have been produced by powder sintering for more than 100 years. Porous aluminum casting is a relatively new material, which has gained a foothold on the market because of its unique technical characteristics: Nominal (guaranteed) filtration is defined by the minimal pore size – the particles cannot penetrated into the pore area and are stored at the surface. The minimal pore size of porous aluminium casting is within 35-200μm. The fine fraction slippage coefficient is detected according to the number of particles, which size is smaller than the nominal filtration that passes through the filtering element. The low fine fraction slippage coefficient is characteristic of porous aluminium and demonstrates that particles stay in the filtering element bulk, which is a consequence of graze percussion mechanism of reduction: the turbulent current occurs due to the significant relation of maximum and minimum pore size (4-8 times) and absence of smooth transition between them in the flow tube. As the fine fraction slippage coefficient is low the average filtration in porous aluminium is considerably lower than the nominal one. The average filtration of sintered filtering elements is close to nominal, because the less effective reduction mechanism at the surface prevails over the graze percussion mechanism due to the negligible relation between minimal and maximum pore sizes and smooth form of the flow tube. The porosity is determined the operation life before cleaning. The PCA porosity is regulated within 50-70%, the sintered filters porosity is lower only within 20-35%. Cleaning of PCA filtering elements is quite conventional, i.e. rinsing in kerosene or by reverse water flow or compressed air. The hydraulic resistance of porous aluminium is significantly lower than that of the sintered powder filtering elements with the same filtration characteristics. The PCA filtering elements price is a pleasant supplement to the aforementioned advantages.

/A.B. Finkelshtein DSc (Technology), 2012/

Porous aluminium for noise suppression

The exhaust noise appears because of high gas velocity. The simplest air silencer is a porous permeable glass. It is set on the exhaust opening and prevents noise appearance because of gas velocity reduction at the disposal area. The air silencer is supposed to provide pressure reduction during the working cycle without destruction under gas jet pressure impact. This requirements are contradictory as for the fast pressure drop the porous wall should be thin and might be broken by the pressure impact. However, it is possible to increase the the porous glass surface area, but this results in bare room effect, i.e. the sound is formed in the inside volume of air silencer. Porous aluminium casting has optimal characteristics for the air silencer. As compared with the large-scale assembled silencers made of wire thread wastes in the pipe shell, these air silencers have a significantly greater pressure impact that significantly decreases the gas disposal velocity, and thus noise formation level. PCA air silencer comparative tests performed at OJSC 'AvtoVaz' demonstrated the advantages of the model over foreign analogues. As compared with the small air silencers sintered from metal powders, the PCA air silencers provide 5-8 times smaller pressure impact and high dirt capacitance that allows increasing wall thickness at high disposal pressure, that sigificantly broadens application range. The PCA air silencer price is lower and mechanical properties are greater, than that of the powder air silencers. The air silencer constructions, in which the pressure is disposed by air transport through porous wall channels, are developed. This is the unique construction that allows noise level reduction of pneumatic equipment practically to sanitary standards and muffles small arms shooting. These air silencers may be produced using the infiltration technique because the mechanical treatment of the work pieces is required. The PCA air silencer is the integrated solution for your pneumatic equipment!

/A.B. Finkelshtein DSc (Technology), 2012/