Patent ID: 7343759

Claim:
A method for removing volatile vapors from a storage vessel, comprising: establishing a flow of a stream of volatile vapors from the storage vessel; directing the stream through a vapors side of a first low temperature condenser having an inlet and an outlet; starting a refrigerant flow through a refrigerant side of the first low temperature condenser; condensing a portion of the stream flowing through the vapors side of the first low temperature condenser; freezing a portion of condensate formed in the vapors side of the first low temperature condenser until a pressure drop through the vapors side of the first low temperature condenser exceeds a setpoint; directing the stream from the outlet of the vapors side of the first low temperature condenser through a vapors side of a second low temperature condenser having an inlet and an outlet; reducing the refrigerant flow through the refrigerant side of the first low temperature condenser and starting the refrigerant flow through a refrigerant side of the second low temperature condenser; melting the frozen condensate in the vapors side of the first low temperature condenser by heat contained in the flow of the stream of volatile vapors; and circulating the stream back to the storage vessel.