Gas condensing high bypass hot air balloon burner

A conventional hot air balloon burner is just a big flame burning up into the interior of the envelope.

There are, however, some disadvantages to this. The combustion is not that efficient, and one of the combustion products - water - is a liquid at ambient temperatures; as it cools, its volume decreases by orders of magnitude, and as the flight progresses, the envelope is pretty much full of just combustion products.

The answer to this is the new BorgCo Gas condensing high bypass hot air balloon burner. Borrowing technology from domestic hot water/heating systems, the enclosed burner (the enclosure being built of lightweight aerospace-grade materials such as ceramics) heats a separate airstream, driven by a minature gas turbine operating in a venturi tube, which passes through a jacket around the burner to the desired temperature, and cools the exhaust gases to the point that water vapour condenses out. The remaining warm air is also piped into the envelope, and the condensate (actually a strong solution of nitric acid) is simply allowed to dribble out randomly on whatver's under the basket at that moment.