Ecodyne Corporation

Christopher J Halbfoster

Donald J Butterworth

Robert Loudon

A filter element having a perforated tubular core and a plurality of layers of strand material wound about the tubular core. The outermost layer has the ability to retain particles smaller than those retained by the innermost layer. The size range of particles retained by the outermost layer is from one to twenty-five microns and the size range of particles retained by the innermost layer is from twenty-five to one hundred microns. According to the method of invention, the filter element is used to purify liquids through the steps of precoating, delivering liquid through the filter, periodically backwashing the filter, and precoating the filter again.

Apparatus and method

A method and filter bed for removing impurities from liquids wherein the filter bed comprises a mixture of treated filter aid material and an active particulate material having opposite surface charges in aqueous suspension. The filter aid material has been treated to produce the desired surface charge. The identity of the active particulate material depends on the application. Examples are organic polymeric absorbents, zeolites, bentonite, zirconium oxide, zirconium phosphate, activated alumina, ferrous sulfide, activated carbon and diatomaceous earth.

Purification of liquids with treated filter aid material and active

A method for preparing an improved filter material, together with the improved material prepared thereby and an improved method for removing impurities from a liquid. The filter material comprises a mixture of ion exchange resin particles and treated filter aid material. In the preferred embodiment, the ion exchange resin particles comprise a mixture of anion and cation exchange resin particles, and the filter aid material is treated with a chemical compound to produce a positive surface charge thereon. The filter aid material may be further treated with a second compound to produce an enhanced negative surface charge.

Charged filter aid material and ion exchange bed

Impurities are removed from a liquid by passing the liquid through an improved filter bed. The filter bed comprises a mixture of oppositely charged particles of filter aid material, the particles normally having a surface charge in aqueous solution. A portion of these particles are treated with a chemical compound to produce a surface charge that is opposite from the normal surface charge. These oppositely charged particles clump in aqueous suspension, and produce a filter bed which is capable of removing suspended particles with very high efficiency, while maintaining a relatively low pressure drop across the filter bed.

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Greenbrook, NJ, United States of America

Christopher J Halbfoster