DISPENSER NITROGEN PURGE

• US 20140345708A1
• Filed: 05/24/2013
• Published: 11/27/2014
• Est. Priority Date: 05/24/2013
• Status: Abandoned Application

• Current Assignee: Clean Energy Fuels Corp.
• Original Assignee: Clean Energy Fuels Corp.
• Inventors: Oldham, Kenny, Martin, Devin
• Application Number:
  US13/902,601
• Publication Number:
  US 20140345708A1
• Time in Patent Office: Days
• US Class Current: 137/341
• CPC Class Codes: F17C 13/10 Arrangements for preventing freezing
• CPC Class Codes: F17C 2205/0355 Insulation thereof
• CPC Class Codes: F17C 2221/014 Nitrogen
• CPC Class Codes: F17C 2221/033 Methane, e.g. natural gas, CNG, LNG, GNL, GNC, PLNG
• CPC Class Codes: F17C 2223/0161 cryogenic, e.g. LNG, GNL, PLNG
• CPC Class Codes: F17C 2223/033 Small pressure, e.g. for liquefied gas
• CPC Class Codes: F17C 2227/0304 using an electric heater
• CPC Class Codes: F17C 2227/0372 in the gas
• CPC Class Codes: F17C 2227/044 by purging
• CPC Class Codes: F17C 2250/032 using computers
• CPC Class Codes: F17C 2250/0439 Temperature
• CPC Class Codes: F17C 2250/0631 Temperature
• CPC Class Codes: F17C 2260/032 Avoiding freezing or defrosting
• CPC Class Codes: F17C 2265/06 Fluid distribution
• CPC Class Codes: F17C 2270/0139 Fuel stations
• CPC Class Codes: Y10T 137/6606 With electric heating element

Abstract

A dispenser nitrogen purge and heater system for a liquid natural gas (LNG) fueling dispenser, comprising a nitrogen purge enclosure; a nitrogen container containing nitrogen; a nitrogen feed line for feeding nitrogen from the nitrogen container to the nitrogen purge enclosure; a heater for heating an interior space within the enclosure; and a fan assembly for circulating the nitrogen within the interior space

Claims

1. A dispenser nitrogen purge and heater system for a liquid natural gas (LNG) fueling dispenser, comprising:

a nitrogen purge enclosure;

a nitrogen container containing nitrogen;

a nitrogen feed line for feeding nitrogen from the nitrogen container to the nitrogen purge enclosure;

a heater for heating an interior space within the enclosure; and

a fan assembly for circulating the nitrogen within the interior space.

2. The system of claim 1, wherein the heater maintains the interior space of the nitrogen purge enclosure at a temperature above freezing.

3. The system of claim 1, wherein the heater is controlled to keep the temperature of the interior space within a desired temperature range.

4. The system of claim 1, wherein the nitrogen purge enclosure forms a portion of the LNG dispenser.

5. The system of claim 1, wherein the fan assembly comprises a fan attached to the nitrogen purge enclosure by way of a magnetic coupler.

6. The system of claim 1, wherein nitrogen is introduced through a nitrogen inlet of the enclosure at a rate of approximately 1 cubic feet per minute to ensure a positive purge pressure.

7. The system of claim 1, wherein nitrogen is introduced into the enclosure at a rate of between 0.75 and 1.25 cubic feet per minute to ensure a positive purge pressure.

8. The system of claim 1, wherein the nitrogen purge and heater system inhibits ice and frost from generating in the interior space during operation of the LNG dispenser.

9. The system of claim 1, wherein the nitrogen purge and heater system eliminates frost from generating on an exterior of the nitrogen purge enclosure.

10. The system of claim 1, wherein the nitrogen purge enclosure is formed of sheet metal that is sealed to minimize the nitrogen purge flow rate required to maintain a substantially moisture-free environment in the interior space.

11. The system of claim 10, wherein a top panel of the enclosure is removable to allow maintenance access.

12. The system of claim 1, wherein the nitrogen purge enclosure is completely sealed such that it is substantially air tight.

13. The system of claim 1, wherein the enclosure is sealed to an extent needed to minimize a nitrogen leak rate of the enclosure to allow a relatively low nitrogen container capacity.

14. The system of claim 1, wherein the nitrogen purge and heater system prevents frost from generating on process piping within the enclosure.

15. The system of claim 14, wherein the process piping includes piping insulation in the form of pipe wrap that is secured by custom fitting and VELCRO.

16. The system of claim 1, wherein the nitrogen container comprises an on-site nitrogen generator.

17. The system of claim 1, wherein the nitrogen container comprises a nitrogen storage bottle.

18. A dispenser nitrogen purge and heater system for a liquid natural gas (LNG) fueling dispenser, comprising:

a nitrogen purge enclosure;

a nitrogen container containing nitrogen;

a nitrogen feed line for feeding nitrogen from the nitrogen container to the nitrogen purge enclosure;

a heater for maintaining the interior space of the nitrogen purge enclosure at a temperature above freezing, wherein the heater is controlled to keep the temperature of the interior space within a desired temperature range; and

a fan assembly for circulating the nitrogen within the interior space;

wherein the nitrogen purge enclosure forms a portion of the LNG dispenser.

19. The system of claim 18, wherein nitrogen is introduced through a nitrogen inlet of the enclosure at a rate of approximately 1 cubic feet per minute to ensure a positive purge pressure.

20. The system of claim 18, wherein nitrogen is introduced into the enclosure at a rate of between 0.75 and 1.25 cubic feet per minute to ensure a positive purge pressure.

21. The system of claim 18, wherein the nitrogen purge enclosure is formed of sheet metal that is sealed to minimize the nitrogen purge flow rate required to maintain a substantially moisture-free environment in the interior space.

22. The system of claim 21, wherein a top panel of the enclosure is removable to allow maintenance access.