Natural Gas Pipeline Heater
Cold Weather Technologies
What is the Cold Weather Technology Principle?
The Heat Driven Loop
- Utilizes two-phase thermosyphon technology in an evacuated, closed loop system with no moving
components – indirect heating.
- Utilizes the energy release which occurs when steam transforms from vapor to a condensed state.
- Consists of an evaporator and a condenser/heat exchanger section.
- Large quantities of heat can be transported quickly, efficiently, and safely.
- Swordfish ribbon burners generate the necessary heat
- Heat rises from flame bed
- Water boils out of the water/glycol mixture
- Low-pressure, low-temperature steam rushes to the
- The system is kept on vacuum
- Low-temperature natural gas enters the heater
- Heat exchanges from the condensing system to the
natural gas in the coil
- High-temperature natural gas leaves the heater
- The phase change of steam to water heats the natural
gas and results in condensate
- Condensate returns to be reheated
Fuel Consumption Comparison Between
Traditional & CWT Heaters
The system uses the latent heat of vaporization for the heat transfer. Note in the chart above a large amount of energy required to turn water into steam. When you condense that water, that energy is released to heat the gas.
Using steam for the heat transfer results in very high efficiency. As the system operates at less than 14.7 psi and 250°F, it is not a pressure boiler and does not need ticketed operators nor does it have to be registered.
The CWT operates on a vacuum. Why?
he CWT boils water in a vacuum to make steam for the heat exchange process. There are a number of reasons. First and foremost, the boiling point of the water is reduced significantly under a vacuum. Water at atmospheric pressure boils at 212°F. In the CWT the water boils at about 110°F. Using the latent heat of the steam to heat the process fluid makes us very efficient.
The vacuum also reduces corrosion as there is no air in the system and allows the CWT to operate at less than 14.7 psig and 250°F so it is not considered a pressure boiler.
What kind of fuel does the CWT use and at what pressure?
The CWT can operate on natural gas or propane and can be modified to operate on liquid fuels as well. Gas needs to be delivered to the heater at 5.0 psig.
Does the CWT require utility power?
No utility power is required for the CWT. The unit operates with internally generated power. A high quality furnace power-pile system creates a 700 mV current from the standing pilot. This is sufficient to provide the power required to operate and control the system.
As a result the unit is impervious to power failure; the only utility required is natural gas.
There is no need to provide expensive utility power nor is an electrician required for installation or maintenance.
How much fluid is required and do I need secondary containment?
The CWT uses a 50/50 water-glycol mixture for the heat exchange. The standard glycol is propylene-based and is none toxic. The volume is significantly less than a conventional indirect heater and is generally less than 15 gallons. Secondary containment is not required in most jurisdictions.
A device is a sealed unit and all required fluids are supplied with the purchase. In larger units, this is a significant advantage in both capital and operating cost impacts. A large conventional line heater will often hold barrels of glycol while the CWT requires gallons.
On an ongoing basis, fluid is added to a conventional glycol bath type heater as it is evaporated away – the CWT has a sealed system and does not require additional glycol over time.
There is no need to monitor the mixture to add fluid to the CWT.
What do I need to do to install the CWT?
The CWT needs to be set on a solid foundation. The system operates better outside so no building is required. The installation consists of 1) hooking up the fuel supply, 2) connecting the process lines in and out, and 3) installing the operating temperature control in the process stream.
What sizes are available?
The CWT comes in a number of standard sizes and can be scaled to as large an application as is required. The system can be turned –down and tuned to best match the application and further increase efficiency.
How noisy is the heater?
The CWT is completely silent while operating and is suitable for urban and semi-urban areas.
What about emissions?
The CWT burns significantly less fuel than conventional systems and burns it more efficiently. Emission reductions in the order of 50% of conventional technology can be expected.
How long have the CWT’s been in service and how many are in the field?
The first CWT heaters were in the field in 2001 in heavy oil heating applications. The first natural gas heaters were installed in 2003. There are over 200 natural gas line heaters in service across North America.
What maintenance is required on a CWT?
On an annual basis, the flame arrestor should be blown out with compressed air to ensure enough air can pass to support combustion. The safeties and shutdowns should be function tested and a glycol analysis is done.
The pressure coil should be inspected every 10 years or so to monitor for corrosion.
I am a long way from Alberta Canada where the CWT is built. How can we ensure I get adequate service and support.
CWT offers 24-hour telephone support and troubleshooting.
The CWT is very simple to service and the components are standard furnace parts. Our representatives in your area will be able to handle most service concerns and provide support.
In those cases where a CWT technician is required, we can be there tomorrow.
I am reluctant to try something new. What assurances can I have that the heater will perform as promised?
CWT can provide you with a list of references from companies that have CWT units in service. We also provide a Performance Guarantee. If at the end of the first heating season you are unhappy with your CWT we will buy it back.