Method for maximizing availability of heat exchangers for removal of volatile vapors from a storage vessel

A method of recovering hydrocarbons from a storage vessel comprising:

• flowing a stream of vapors from the vessel;
• directing the stream through a first heat exchanger having an inlet and an outlet to cool the vapor stream;
• directing the stream through a second heat exchanger having an inlet and an outlet to further cool the stream and condense at least a portion of the vapors;
• monitoring the pressure drop between either the inlet of the first heat exchanger or the inlet of the second heat exchanger and the outlet of the second heat exchanger to detect frozen condensate in the second heat exchanger;
• and
• remediating the pressure drop by redirecting a relatively warm portion of the stream to a portion of the second heat exchanger containing the frozen condensate to melt the frozen condensate.

A method of recovering material from a vessel comprising:

• flowing a stream of vapors from the vessel;
• directing the vapor stream through a first heat exchanger and then though a second heat exchanger in series with the first heat exchanger to condense at least a portion of the vapors;
• freezing at least a portion of the condensate in the second heat exchanger;
• monitoring the pressure drop across either the second heat exchanger or both the first and second heat exchangers to detect plugging due to frozen condensate;
• and
• remediating the pressure drop by redirecting the path of the vapor stream to flow a relatively warmer portion of the vapor stream to an affected portion of the second heat exchanger containing the frozen condensate.