Boating & Marine
Open flames used in heating, cooking, and bathing aboard can pose a serious threat to a boater's safety. GHT's flameless technology eliminates this danger of fire. It can change the way we heat yachts, winterize boats and maintain the temperature of the goods we import and export. Plus, with reduced needs for shore power in port, harbors and marinas conserve energy. Easy and efficient temperature regulation of aquariums helps reduce stress on fish, and some hatcheries require a constant, uniform heat of their egg wash water in order to conduct successful research. In cold, deep water, marine biologists, rescue workers and recreational divers can benefit from mobile, non-electric portable flameless heaters, as well.
In depth: A revolutionary membrane catalytic heater system assists divers
We present a case study in the application of our catalytic heater system for divers. The particular characteristics that a scuba diver requires in a mobile heater are:
Make the system as simple as possible
The heater must be separate from the diver's air supply
A pure compressed oxygen supply will be the most compact, lightweight and efficient means of enabling the heater itself to breathe
Automatic thermostatic control for ease of use and instrumental sensing of temperature
Safe operation from 1 to 10 atmospheres (14.7 to 147 psi)
Insensitivity to ambient pressure changes
Regulators that are protected from freezing in cold conditions
We discussed a variety of system designs. They vary in the method in which heat is uniformly delivered and distributed to the diver's body. The major systems considered are as follows:
Closed loop water circulation
Open loop water circulation
Open heat pipe system
Flexible sealed heat pipe systems at ambient pressure
Rigid sealed heat pipe system
Metallic conductors
Exhaust gas stream circulation
Aspirated exhaust gas stream and water circulation
We chose the aspirated exhaust stream circulation with ambient water injected into the flow with an aspirator as the best solution. This allows the temperature from the heater to be appropriately reduced and also captures the heat from exhaust by adding some of the carbon dioxide offgas to the water solution. If a malfunction of the heater or internal leak occurs, the exhaust flow will be primarily water. Unburned fuel in this situation is quickly dissolved and carried away by the water. Leaks are easy to detect in a dry suit. The thermostat sensor will throttle back the heater if there is an abnormal temperature rise due to a blocked aspirator inlet flow.
A thermostat controls the oxygen delivery. A special membrane controls fuel delivery to achieve an approximate stoichiometric mixture of fuel and oxygen while the oxygen concentration varies by a factor of 10 with water depth.
Advantages of a methanol fueled GHT system include:
Methanol fuel is water-soluble and would not present a hazard in a marine environment
Alternative gaseous fuels such as hydrogen, butane, and propane present a storage hazard in boats and could build up under water and in trapped spaces, creating an explosive mixture with air or oxygen. Naphtha and kerosene are liquid fuels but also have a similar hazards because of lack of solubility in water and due to their low density will float to the surface of the water. (Ethanol, however, could be used.)
The membrane eliminates the requirement of a fuel-injected or carbureted system. It will also eliminate the chance of flooding the heater with liquid fuel. Although it may be necessary to provide a means of equalizing the pressure in the combustion chamber when the oxygen supply is cut off and the temperature drops. It will pull a vacuum against the check valve
No active pump required
