Engine Filters

Introduction 5B. Engine filters 5C. Oil-water separators 5D. Oil cleaning 5E. Hydraulic systems 

This section of the Handbook is entirely devoted to the utility filtration applications involving machinery fluids - mostly to do with those used in engines and hydraulic systems. Some of the subject matter has already been covered in Section 4, but it was done there from the point of view predominantly of aqueous fluids, whereas now the emphasis is on the treatment of oils. 

The subject matter of this section is also largely concerned with liquid filtration, but coverage is included of engine air filtration for the sake of completeness. 

The engines used in automotive vehicles of all kinds, and as stationary power sources, consume air and liquid fuel as their energy source, and rely on liquid lubricant and coolant to maintain them in good condition. Another fluid - the exhaust gas - is currently of considerable environmental concern, as a source of atmospheric pollution. So there are five fluids involved in the operation of an engine, all needing filtration for one reason or another  

As with every other field of human endeavour, the demands of modem society are making the operation of engines of all kinds more difficult. Ambient air is dirtier, especially with the products of engine combustion, or engines are used in less amenable places where the air is intrinsically more of a problem - desert areas, where the air is full of sand, or littoral and off-shore installations, where the air is laden with salt spray. Demands on the engine are more stringent, temperatures 

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Figure 4-78. Tubular in-line pressure filter with reusable elements. The flow unfiltered liquid enters the inlet port, flows upward, around, and through the media, which is a stainless steel or fabric screen reinforced by a perforated stainless steel backing. Filtered liquid disch lrges through the outlet (top) port. Because of outside-to-lnside flow path, solids collect on the outside of the element so screens are easy to clean. By permission, Ronningen-Petter Engineered Filter Systems, Bulletin RP-2.

Gas-air mixer The gas volume has to be mixed with an about 1.1 times larger, adjustable air flow, which is almost stoichiometric. The total gas-air flow passes through the normal engine filter for final dust removal. 

The application of nonwoven filter media in the fuel and oil filter segment of the transportation industry is affected significantly by governmental regulations related to the environment and the desire for longer intervals between engine filter replacements. 

Recently, for the example ofpoly(3-hydroxybutyrate) (PHB) and a number of its composites [14-16] we have studied physical-chemical, dynamic and transport characteristics of macroscopic biodegradable matrices and microparticles of PHB which were designed for controlled dmg release [16, 17]. High biocompatibility, controlled biodegradation and appropriate mechanical properties allow one to consider this biopolymer as one of the most promising biomedical polymers. Besides therapeutical aims, PHB is widely used as bone implants, nervous conduits, matrices in cell engineering, filters and membranes, in cardiology and in the other areas [14,18,19]. 

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