Patent ID: 7481375

Claim:
An apparatus for controlling the temperature of a process fluid, the apparatus comprising: a cryogenic fluid tank containing a cryogenic fluid within an interior portion of the cryogenic fluid tank; a process fluid tank comprising an inlet and an outlet through which a process fluid circulates through an interior portion of a the process fluid tank, the process fluid tank spaced from the cryogenic fluid tank to define an insulating space between the cryogenic fluid tank and the process fluid tank; a plurality of heat transfer devices transferring heat between the process fluid in the process fluid tank and the cryogenic fluid in the cryogenic fluid tank, each of the heat transfer devices extending at least partially through both of the interior portions and between opposing sidewalls of the process fluid tank and the cryogenic fluid tank, each of the heat transfer devices comprising a first portion positioned in the cryogenic fluid tank wherein the first portion contacts the cryogenic fluid in the cryogenic fluid tank, a second portion positioned in the process fluid tank wherein the second portion contacts the process fluid in the process fluid tank, and a third portion positioned in the insulating space between the cryogenic fluid tank and the process fluid tank; and a heater being controlled to add heat to the third portion of the heat transfer devices to control the rate of heat transfer between the process fluid in the process fluid tank and the cryogenic fluid in the cryogenic fluid tank.