Boil-off gas removal system
AssigneeChicago Bridge & Iron Company
InventorsJack Sudduth, Warren Carpenter
Life of this patent
Estimating the term…
Abstract
In a new boil-off gas removal system for a liquid storage tank, boil-off vapor from the storage tank is first pressurized in the low-stage compressor. The pressurized vapor may be cooled to near cryogenic temperature in a cooler that can include a preliminary cooler and/or a high-pressure gas exchanger in which the pressurized vapor is cooled against boil-off vapor. The pressurized vapor may also be cooled by the addition of cryogenic liquid through a branch on the liquid supply line running from the low-stage pump in the storage tank. The cooled, pressurized vapor is directed to a heat exchanger where the cool, pressurized vapor travels in a path in which it is condensed against cryogenic liquid that travels in another, separate path.
Claims14
A boil-off gas removal system for a liquid storage tank comprising:
- a vapor outlet and a separate liquid outlet on the storage tank;
- a low-stage compressor that is capable of pressurizing boil-off vapor;
- a branch from the liquid outlet through which cryogenic liquid can be introduced to a pressurized vapor line leading from the low-stage compressor;
- a cooler that receives pressurized vapor from the compressor and cools it to at least near cryogenic temperature;
- a heat exchanger in which cooled, pressurized vapor travels in one path and is condensed against cryogenic liquid that travels in another, separate path;
- and
- an output line from the heat exchanger that directs the condensed vapor for further pressurization.
A boil-off gas removal system for a liquid storage tank comprising:
- a vapor outlet and a separate liquid outlet on the storage tank;
- a low-stage compressor that is capable of pressurizing boil-off vapor;
- a cooler that receives pressurized vapor from the compressor and cools it to at least near cryogenic temperature;
- a heat exchanger in which cool, pressurized vapor travels in one path and is condensed against cryogenic liquid that travels in another, separate path, the cryogenic liquid coming from the liquid outlet on the storage tank;
- and
- an output line from the heat exchanger that directs the condensed vapor for further pressurization.
A boil-off gas removal system for a liquid storage tank comprising:
- a low-stage compressor that is capable of pressurizing boil-off vapor from a vapor outlet on the storage tank;
- a branch through which cryogenic liquid can be introduced to a pressurized vapor line leading from the low-stage compressor;
- a heat exchanger in which cooled, pressurized vapor travels in one path and is condensed against cryogenic liquid from a separate liquid outlet on the storage tank that travels in another, separate path;
- and
- an output line from the heat exchanger that directs the condensed vapor for further pressurization.
A boil-off gas removal system for a liquid storage tank comprising:
- a low-stage compressor that is capable of pressurizing boil-off vapor from a vapor outlet on the storage tank;
- a branch on a liquid supply line through which cryogenic liquid can be introduced to a pressurized vapor line leading from the low-stage compressor, the branch enabling the cooling of pressurized vapor in the pressurized vapor line to within about 5 degrees F. of the temperature of liquid in the liquid supply line;
- a heat exchanger in which cooled, pressurized vapor travels in one path and is condensed against cryogenic liquid that travels in another, separate path;
- and
- an output line from the heat exchanger that directs the condensed vapor for further pressurization.
Dependencies are inferred from the claim text.