US Patent 7870747 Fogless ambient air vaporizer

In the method of using ambient air to vaporize liquefied gas, the steps include transferring heat from a stream of ambient air to a stream of liquefied gas, thereby cooling the air stream, and vaporizing the liquid; transferring heat from a source into the cooled air stream; and then discharging the heated air stream to atmosphere, sufficient heat being transferred to obviate objectionable fog production resulting from step c).