I am trying to find the most power efficient method for heating a metal tube in order to heat up the airflow within it. I came across the Minco mica heater but when I talked to another engineer they said it would be just as effective to simply wrap the cylinder in heater wire and then put ceramic tape over the top. Is there a good way to determine which route is better without buying and trying?
I am trying to maximize airflow through the tube, hence heating the tube itself, and not heating the air directly inside.
I am not stuck on a cylinder, necessarily, but from a mechanical standpoint, it seemed like the most effective shape to take advantage of the heat, but that was possibly a terrible assumption.
Best Answer
Heating the cylinder is an inefficient way to heat the air inside. This is because the cylinder loses heat to the outside, as well as to the air inside. A better scheme would be a heater that warms the center of the (presumably streamline) airflow, and perhaps a porous plug or baffle at the outflow end of the air stream that conducts heat so that the air becomes more uniform in temperature. As for 'maximizing airflow', that would result in lower temperature for any given heating power. Is that the real goal?