Development of a high efficiency radiation converter using a spiral heat exchanger

Heating by radiation is widely used for materials processing. Electrical radiant heaters are the most commonly used heaters. Electricity is expensive and the combustion of fossils fuels for electricity production emits CO ₂. In order to convert the energy from the fuel to radiation energy directly and efficiently, our group has developed a compact, high efficiency, radiation converter using a spiral heat exchanger to recover the energy from high-temperature exhaust gas. The spiral heat exchanger has a weld-free construction to prevent cyclic thermal stress, and is constructed from inexpensive ferrite steel plates. The combustion chamber, equipped with a swirler to mix the gas fuel and air, can achieve stable combustion. The distribution of the surface temperature on the radiant tube was measured by a radiation thermometer, called a thermo viewer, and then the radiant energy emitted from the radiant tube was estimated. The efficiency of the spiral heat exchanger was measured from the temperature of the inlet air and exhaust gas. The heat exchanger achieved a high effectiveness, and heat loss from the exhaust gas was minimized. Consequently, a highly efficient radiation converter was produced to convert the fuel energy to radiation energy.