VORTEX PILOT GAS HEATER (VPGH)

The Vortex Pilot Gas Heater (VPGH) protects pilot-operated gas regulators from freeze-off by self-heating pilots at pressure regulation stations. The VPGH is a flameless, coilless, energy-saving and maintenance-free alternative to conventional pilot heaters, such as Catalytic Pilot Gas Heaters and Electrical Pilot Gas Heaters.

Overview

Since introduction in 2001 the Vortex Pilot Gas Heater has been applied in all types of natural gas delivery applications: district regulator stations, town border stations, power plant combustion turbine fuel gas and ethanol production plant fuel gas delivery. The Vortex Pilot Gas Heater is Class 1, Division 1 explosion proof device that meets and/or exceeds all federal and state requirements for regulator station design and applications.

The core of the Vortex Pilot Gas Heater is a proprietary Self-Heating Single Path vortex tube, operating under the station's available gas pressure differential converting the internal energy of the decompressing gas flow into highly intensive heat flux. The released thermal energy is then applied to the pilot gas (load gas) as it travels through a heat exchanger set up on the vortex tube's walls. A portion of the generated heat flux is also applied to warm up the vortex tube's pressure reducing inlet nozzles (Non Freeze provision), thus allowing for the VPGH to make a non-freeze pressure cut of non pre-heated gas.

Advantages

Effective:
- Adds up to 90°F to the pilot supply gas
Efficient:
- Heats pilot gas as an outcome of routine gas pressure reduction at the PRS
- No lost gas
Durable:
- Not a single VPGH has required replacement after installation, including the original units installed some 14 years ago
- Not sensitive to wet feed gas
Reliable:
- No moving parts
- No chance of overheating
- Maintenance-free
- No single VPGH failure has been reported among the 5,000+ units currently installed worldwide
- Easy to install or retrofit in new or existing facilities

Configuration

Available in 2 designs:

Single Path (VPGH-SP) has a single heating chamber to serve one pilot at a time.
Dual Path (VPGH-DP) can simultaneously serve two pilots.

Working pressure is 1500 psig or 100 barg. Can be built for higher working pressure upon request.

Applicability:

Effective in practically any operating environment.
A few extreme examples include:
- Handling a single pressure cut of over 1,000 psi pressure differential of non preheated gas while operating outdoors under ambient temperatures that can reach as low as -44°F.
- Operating while submerged in water (pit installations).
- While working with sulfur-containing flow, it maintains the sulfur content as vapor, which prevents the sulfur from depositing in the pilot orifice.

Applications

Vortex Pilot Gas Heater Mini Case Study #1

Vortex Pilot Gas Heater Mini Case Study #2

Situation:

A Pressure Regulation Station with a 250,000 BTU rated Water Bath Heater (Line Heater) set at 120°F to preheat the gas flow that is upstream of the 900 to 135 psi pressure regulator. UVI's client installed the Vortex Pilot Gas Heater at the Station to separately heat the pilot flow to a measured pilot gas temperature of 135°F at the VPGH discharge.

Results:

The Water Bath Heater set up temperature was reduced to 85°F (35° less) yet still maintained 32°F at the Station outlet.

Situation:

Pressure Regulating Stations with the inlet pressure of 55 barg (808.5 psig), delivery pressure of 23,5 barg (345.5 psig) and the inlet gas temperature of 7ºC (45ºF). To overcome the Joule-Thomson temperature drop in the depressurized gas of 16ºC (61ºF) and keep the pilot gas at positive temperatures, a Line Heater was used all year at both Stations. Before implementing the VPGH solution, the total fuel cost of the gas pre-heat was $247,000 in 2011.

Results:

After installing a Dual Path Vortex Pilot Gas Heater at both Stations, UVI's client was able to shut down its line heaters during the summer months and reduce the gas discharge temperature to 0ºC (32ºF) in the winter time. The estimated savings for the client in fuel gas is $150,000/year.