SYSTEMS AND METHODS FOR PREVENTING ICE DEPOSITION ON A GAS VENTING OUTLET

1 . A system comprising:

a vacuum jacketed pipe that has an inlet end configured to flow a gas to an outlet end of the vacuum jacketed pipe;

a gas venting outlet that includes a vent pipe connected axially to the outlet end of the vacuum jacketed pipe and configured to vent the gas to an atmosphere; and

a first heating cable that is spirally wrapped around the vent pipe and configured to prevent ice deposition on the gas venting outlet.

2 . The system of claim 1 , wherein the first heating cable is a first self-regulating heating cable.

3 . The system of claim 2 , further including:

a second self-regulating heating cable,

wherein:

the second self-regulating heating cable is spirally wrapped around the vacuum jacketed pipe and is located adjacent to the first self-regulating heating cable; and

the second self-regulating heating cable is spirally wrapped around the vent pipe and is configured to prevent ice deposition on the gas venting outlet.

4 . The system of claim 3 further including insulation surrounding the first self-regulating heating cable and the second self-regulating heating cable.

5 . The system of claim 4 further including a shroud configured to protect the insulation.

6 . The system of claim 1 , wherein preventing ice deposition on the gas venting outlet requires less than 1000 Watts.

7 . The system of claim 1 further including insulation surrounding the first heating cable.

8 . The system of claim 7 further including a shroud configured to protect the insulation.

9 . The system of claim 8 , wherein the shroud includes a hood configured to reduce an amount of wind driven rain or snow entering the vent pipe.

10 . The system of claim 1 wherein preventing ice deposition on the gas venting outlet includes raising an atmospheric temperature at the gas venting outlet above a dewpoint.

11 . The system of claim 1 wherein:

the first heating cable is a first self-regulating heating cable that includes two conductors and a conductive core that surrounds the two conductors;

the conductive core is configured to increase a distance between the two conductors in response to the conductive core heating up; and

the conductive core is configured to decrease the distance between the two conductors in response to the conductive core cooling down.

12 . The system of claim 11 , wherein the first self-regulating heating cable is configured to keep a temperature of the first self-regulating heating cable within a range of 339 degrees Kelvin to 347 degrees Kelvin.

13 . The system of claim 1 , further including:

a power controller configured to prevent ice deposition on the gas venting outlet by providing electric power to the first heating cable.

14 . The system of claim 13 , further including:

a temperature sensor configured to produce a sensor output that indicates a temperature of the first heating cable,

wherein the power controller is configured to keep the temperature of the first heating cable within a range of 339 degrees Kelvin to 347 degrees Kelvin.

15 . A method comprising:

flowing a gas having a gas temperature lower than 228 degrees Kelvin to an outlet end of a vacuum jacketed pipe;

venting the gas to atmosphere via a gas venting outlet that includes a vent pipe connected axially to the outlet end of the vacuum jacketed pipe; and

raising an atmospheric temperature at the gas venting outlet above a dewpoint by electrically powering a first heating cable that is spirally wrapped around the vent pipe.

16 . The method of claim 15 , wherein the first heating cable is a first self-regulating heating cable.

17 . The method of claim 16 , wherein:

a second self-regulating heating cable is spirally wrapped around the vacuum jacketed pipe and is located adjacent to the first self-regulating heating cable; and

the second self-regulating heating cable spirally is wrapped around the vent pipe and is configured to prevent ice deposition on the gas venting outlet.

18 . The method of claim 15 , wherein preventing ice deposition on the gas venting outlet requires less than 1000 Watts.

19 . A system comprising:

a piping means for flowing a gas having a gas temperature lower than 228 degrees Kelvin;

a venting means for venting the gas to atmosphere, the venting means connected axially to an outlet end of the piping means; and

a heating means for raising an atmospheric temperature at the venting means above a dewpoint, the heating means spirally wrapped around the venting means.

20 . The system of claim 19 wherein:

the heating means is self-regulating and includes two parallel conductors; and

the heating means is configured to regulate a temperature of the heating means by:

increasing a distance between the two parallel conductors in response to the heating means heating up; and

decreasing the distance between the two parallel conductors in response to the heating means cooling down.