Abstract: Installed at the outlet of the afterburning chamber is a diffuser whose narrow section forms a base for the afterburning chamber. The joint between the afterburning chamber and the diffuser is enclosed by a depression chamber which has a manifold with a circular slot for admitting compressed inert gas, e.g. nitrogen, from the outside. The diffuser accommodates a nozzle for feeding freon into the discharged gas flow. This increases the capacity, head and fire-fighting efficiency of the generator.