Patent ID: 8069677
Filing Date: 2011-12-06
Classification: F17C

Abstract:
1. A process for regasification of LNG to form natural gas, said process comprising the steps of: (a) circulating an intermediate fluid between a vaporizer and an ambient air heater, the intermediate fluid being warmed by exchanging heat with the ambient air as the intermediate fluid passes through the ambient air heater, the intermediate fluid being cooled by exchanging heat with LNG as the intermediate fluid passes through the vaporizer; and, (b) subjecting the ambient air heater to a defrosting cycle by intermittently regulating the temperature of the intermediate fluid fed to the ambient air heater to a temperature greater than zero degrees Celsius using a source of supplemental heat, wherein the ambient air heater comprises a horizontal tube bundle and a vertical tube bundle, when a temperature of the intermediate fluid is above 0° C. the intermediate fluid is directed only through the horizontal tube bundle, and when the temperature of the intermediate fluid is less than or equal to 0° C. the intermediate fluid is directed through the vertical tube bundle.