Patent ID: 8065883
Filing Date: 2011-11-29
Classification: F17C

Abstract:
1. An apparatus for the controlled storage of liquefied gases, comprising an enclosed insulated container providing a liquid space and an ullage space and having an external refrigeration unit, means for withdrawing part of the liquid and feeding the withdrawn part to the external refrigeration unit for subcooling and at least one header for reintroducing the subcooled liquid into the container, the ullage space comprising at least one valve-controlled header and at least one pressure sensor, the liquid space comprising at least two valve-controlled headers at different levels in the liquid space and at least two temperature sensors at different levels in the liquid space, and further comprising a control system linked to the external refrigeration unit, liquid withdrawing means, the pressure and temperature sensors, and the valve-controlled headers to operate the valve-controlled headers in response to signals from the pressure and temperature sensors to adjust a level of refrigeration introduced into the ullage and liquid spaces.