Pressure control device for cryogenic liquid vessel

1. An economizer circuit assembly for a cryogenic liquid vessel assembly, said cryogenic vessel assembly including a first, outer shell and a second, inner shell defining a storage space, said storage space having a liquid in a liquid space and a vapor in a vapor space, said vapor and said liquid being at, or about, the same saturation pressure, said cryogenic vessel having a delivery line extending from outside said first, outer vessel shell into said liquid space, said delivery line structured to draw liquid from said liquid space and pass a flow of said liquid through said delivery line, said economizer circuit assembly comprising:

a vent line extending from outside said first, outer vessel shell into said cryogenic vessel and having a first end and a second end, said first end disposed in said vapor space;

an integration device structured to integrate gas bubbles into a flow of liquid;

said vent line and said delivery line coupled, and in fluid communication at, said integration device; and;

whereby gas from said vapor space is integrated into said liquid flow in the form of bubbles.

2. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 1 , wherein said vent line extending from outside said cryogenic vessel into said cryogenic vessel and having a first end and a second end, said second end extending within said delivery line.

3. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 2 , wherein said vent line second end extends in a generally vertical direction within said delivery line.

4. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 3 , wherein said integration device includes a plurality of perforations disposed at said second end.

5. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 4 , wherein said vent line includes a back pressure regulator.

6. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 5 , wherein said integration device is disposed outside of said first, outer vessel shell.

7. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 1 , wherein said integration device is a venturi assembly.

8. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 7 , wherein:

said delivery line has a diameter;

said venturi assembly is disposed on said delivery line;

said venturi assembly having a conduit with a diameter that is smaller than the delivery line diameter; and

said vent line coupled to said venturi assembly at said conduit with a diameter that is smaller than the delivery line diameter.

9. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 8 , wherein:

said venturi assembly includes a venturi opening; and

said vent line is coupled to, and in fluid communication with, said venturi opening.

10. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 9 , wherein said vent line includes a back pressure regulator.

11. A cryogenic vessel comprising:

a first, outer vessel shell; a

second, inner vessel shell defining a storage space, said storage space having a liquid in a liquid space and a vapor space, said vapor and said liquid being at, or about, the same saturation pressure,

said second, inner vessel shell disposed within said first, outer vessel shell;

a delivery line extending from outside said first, outer vessel shell into said liquid space, said delivery line structured to draw liquid from said liquid space and pass a flow of said liquid through said delivery line;

an economizer circuit assembly comprising:

a vent line extending from outside said first, outer vessel shell into said cryogenic vessel and having a first end and a second end, said first end disposed in said vapor space;

an integration device structured to integrate gas bubbles into a flow of liquid;

said vent line and said delivery line coupled, and in fluid communication at, said integration; and

whereby gas from said vapor space is integrated into said liquid flow in the form of bubbles.

12. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 11 , wherein said vent line extending from outside said cryogenic vessel into said cryogenic vessel and having a first end and a second end, said second end extending within said delivery line.

13. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 12 , wherein said vent line second end extends in a generally vertical direction within said delivery line.

14. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 13 , wherein said integration device includes a plurality of perforations disposed at said second end.

15. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 14 , wherein said vent line includes a back pressure regulator.

16. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 15 , wherein said integration device is disposed outside of said first, outer vessel shell.

17. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 11 , wherein said integration device is a venturi assembly.

18. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 17 , wherein:

said delivery line has a diameter;

said venturi assembly is disposed on said delivery line;

said venturi assembly having a conduit with a diameter that is smaller than the delivery line diameter; and

said vent line coupled to said venturi assembly at said conduit with a diameter that is smaller than the delivery line diameter.

19. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 18 , wherein:

said venturi assembly includes a venturi opening; and

said vent line is coupled to, and in fluid communication with, said venturi opening.

20. The economizer circuit assembly for a cryogenic liquid vessel assembly of claim 19 , wherein said vent line includes a back pressure regulator.