A compact cylindrical vaporizer for simultaneous reduction of a reformate
stream temperature and generation of a process stream is disclosed. The
vaporizer utilizes counter flowing nested tubular portions that spiral
between an outer section of the vaporizer and a central section of the
vaporizer. The return spiral has a larger cross-sectional area than the
inward spiral to accommodate a higher volumetric flow rate of the water
flowing there through as it vaporizes while keeping the fluid velocity
below erosion design constraints. The counter spiraling flow provides a
substantially uniform spatial temperature profile of a reformate stream
flowing on the exterior of the tubular portions. The vaporizer can be
sized to be substantially the same as that of an upstream reactor to
minimize velocity losses and pressure drops in the reformate stream
flowing there through. A plurality of fins are positioned between the
opposing tubular portion to enhance the heat transfer.