Abstract: A tubular vaporizer for vaporizing volatile liquids, and especially hydrocarbon fuels. Liquid fuel is passed into the vaporizer tube, is vaporized by heat transferred through fuel contact with the hot walls, and vaporized fuel exits the vaporizer tube. A hot carrier air stream is passed through the vaporizer with the vaporized fuel, greatly reducing the rate of buildup of deposits on the vaporizer walls; however, fueling of the vaporizer eventually must be shut down to remove the deposits. The deposits are easily removed, and the vaporizer tube completely regenerated, by passing hot air alone through the tube for a period of time. In a preferred embodiment, two parallel-path vaporization tubes and switching means therebetween are provided for alternate use and regeneration cycles, affording a continuous flow of vaporized fuel from the apparatus. The vaporizer is especially useful in providing gaseous fuel for a catalytic hydrocarbon reformer.