Filtration element for severe service applications

Abstract

A filtration module is provided using metallic interconnect tubes that are sealed to carbon or ceramic based tubular filtration elements and that are also sealed to metallic tubesheets which are sealed to a filter housing. A sealed joint is formed between the interconnect tubes and the filtration elements using a metal alloy and an optional metallic plating on the filtration elements. In order to reduce or prevent undesired wicking of the alloy into the filtration element, refractory small solid particles may be added to or formed in the alloy to block the pores and channels in the filtration element at the site of the joint. Wicking can also be reduced by induction, torch or other type of heating where only those portions of the filtration element at the site of the joint is heated so that temperatures adjacent the site are below the solidus temperature of the alloy. When sealing on the inside of the wall of the filtration element, a compressive force may be applied to the outside of the wall during formation of the sealed joint to reduce the opportunity for the joint to fail as a result of the different coefficients of thermal expansion of the filtration element and the interconnect tubes. The use of the metallic interconnect tubes and tubesheets, rather than the conventional elastomers, polymers and rubbers, allows the filtration module to better withstand the high temperatures and corrosive fluids often present in severe service applications. The filtration elements may be reverse osmosis, nanofiltration, ultrafiltration or microfiltration membranes.

Dependencies are inferred from the claim text.