An improved fluid permeable porous electric heating element.

摘要

A fluid permeable electric heating element made by, forming a fibrous precursor 200, coating the fibres of the precursor 200 with a selected material so as to form tubular fibres of the selected material, and heating the coated precursor 200 at a temperature such as to modify the structure of the selected material to provide a desired electrical resistivity of the tubular fibres.