Catalytic heater

Abstract

A catalytic heating system comprising a main catalyst (20, 50) for flameless catalytic burning of fuel gas and a triggering system for initiating the catalytic burning, the triggering system comprising an electrical power source electrically connected to a metallic catalyst portion (104). As electric current flows through the metallic catalyst portion, it is in itself heated as an electric resistance heater to a temperature necessary for triggering the catalytic burning. By using electrical current for direct heating of a catalyst portion, reaction starts as soon as the resistance heating achieves the temperature for initiating the catalytic reaction. As soon as the reaction starts, it is transferred to the main catalyst.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a catalytic heating system comprising a main catalyst for flameless catalytic burning of fuel gas and a triggering system for initiating the catalytic burning, the triggering system comprising an electrical power source electrically connected to an electrical resistance heater for heating a catalyst portion to a temperature necessary for triggering the catalytic burning.BACKGROUND OF THE INVENTION[0002]Catalytic heating for hot water supplies is well known in the art and described, for example, in U.S. Patent No. 4,510,890 by Cowan, U.S. Pat. No. 4,886,017 by Viani, and U.S. Pat. No. 5,709,174 by Ledjeff et al. Though, burning of fuel by combustion is easily started by a piezo spark, it is very difficult to start by such simple means, especially if the system has small dimensions. In order for the flameless catalytic oxidation of the fuel to start, a temperature of typically 150° C. has to be achieved first for the catalyt...

AI Technical Summary

Benefits of technology

[0006]It is therefore the object of the invention to provide a catalytic heating system with a starting mechanism that is easy to implement in small systems having a minimum weight.

Problems solved by technology

Though, burning of fuel by combustion is easily started by a piezo spark, it is very difficult to start by such simple means, especially if the system has small dimensions.

A disadvantage of such systems may be seen in the provision of a combustion chamber, Which makes it difficult to provide small systems, for example portable systems, when using a combustion chamber.

Another disadvantage is the fact that combustion only starts if the oxygen content is between 2% and 9% in the case of propane or butane as fuel.

However, this oxygen-poor mixture results in incomplete burning, such that the combustion products have a strong smell, which requires that these burners also have an afterburner for burning the remaining fuel in the combustion gases.

All in all, this kind of systems are generally large and expensive and not suited for portable devices.

If used for a portable system, which is interesting for hikers and military purpose, relatively heavy batteries limit the usefulness.

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