PS-type cryogenic storage tank.

Abstract

The PS-type cryogenic storage tank is a low temperature storage tank designed to provide double safety against leakage. The tank consists of an inner tank and an outer enclosure. The inner tank contains the low temperature and ultra-low temperature liquefied gases, such as liquefied petroleum gas (LPG) and liquefied natural gas (LNG). Even in the event of an accidental leakage occurring on the inner tank, the outer enclosure of prestressed concrete will serve as an integral secondary barrier to keep the gas from flowing out. This report presents the circumstances surrounding the development of the PS-type cryogenic storage tank, and covers the construction and field testing of a large-scale prestressed concrete structure (6 meters in diameter×6 meters in height), modelled under actual field conditions, to prove its effectiveness as an integral barrier and liquid restraining wall. Tests were also run to demonstrate resistance to seismic shock equivalent to or greater than that of a metal storage tank, and to demonstrate the necessary resistance to low temperature thermal shock to function as a liquid receiving vessel of flat bottomed cylindrical design. The results of these tests and their numerical analyses are reported, as well as the results of numerical analysis concerning structural safety with reference to the radiant heat from hypothetical adjacent fires. A 3, 000 ton ethylene storage tank and two 40, 000 ton LPG storage tanks have been constructed based on the results of this research and development project, and these tanks have received a high evaluation as safe storage facilities.