Pressurized Cooldown of Cryogenic Transfer Lines

One of the most serious limitations imposed on the fast transfer of cryogenic liquids is the transient period that exists during line cooldown. When a cryogenic liquid is suddenly admitted to a transfer line that is at ambient temperature, some portion of the cryogenic liquid must vaporize before the line is cool enough to allow steady liquid flow. While the transfer line is cooling, flow into the line will be limited by the ability of the transfer line to vent the cooldown gas. In systems designed to transfer a given quantity of liquid within a fixed period of time, the duration of this transient period, known as line cooldown time, can be a critical design consideration.