Air heater with burner - has passage from fan to discharge chamber by=passing main heat exchanger

摘要

The air heat comprises a burner, the hot gases from which pass through a heat-exchanger on their way to the flue. A fan delivers the ambient air to be heated via the heat exchanger to a discharge chamber. A passage (15) for part of the air connects the fan (5) to the chamber, bypassing the heat exchanger (13), and containing an auxiliary heat exchanger (16), whose primary side lies between the main one and the flue (17). This bypass passage can be formed by a partition in a heater chamber enclosing the main heat exchanger and the combustion chamber on the one hand and the auxiliary heat exchanger on the other.