POROUS METAL FILTERS FOR LUBRICATING OILS

The USE OF POROUS METALS, manufactured by powder metallurgy, for filtering gases and liquids is not new and the potentiality of this type of filtering medium was realised when the first efforts were made. Such filter elements overcome many disadvantages of the more conventional filter elements using paper, felt and other materials. Firstly, they are everlasting, being easily cleaned by washing, or even by reversing the flow. Secondly, their filtering capacity can be regulated, since the pore size can be closely controlled during manufacture. They also have the advantage over ceramic filters in that they are almost unbreakable. In the early days, however, perfect filtration was not assured because the particle size and shape could not be guaranteed and therefore the degree of filtration could only be specified between rather wide limits. Now, however, powder metallurgy has advanced considerably, and metal particles can be provided in whatever size and shape required. Porous metal elements are easily housed in whatever size and shape of filter is required.