Abstract: An industrial fuel blender having a vaporizer chamber adapted to be partially filled with a liquid fuel additive, heater means for heating liquid fuel additive in the vaporizer chamber, and a fuel blender housing. A base fuel conduit passes through the fuel blender housing through which gaseous base may flow, and a fuel additive conduit communicates between the vaporizer chamber and the base fuel conduit within the fuel blending housing through which vaporized fuel additive may flow. Means are provided for thermally coupling the fuel blender housing with the vaporizer chamber to inhibit condensation of vaporized fuel additive as it flows through the fuel additive conduit and into the base fuel conduit within the fuel blender housing. Valve means are provided for concurrently controlling the flow of gaseous fuel and vaporized fuel additive in the conduits. A venturi is also provided at the junction of the two conduits for drawing the fuel additive into a flowing stream of the base fuel.