Abstract: There is provided a combustion appliance with a safety device. An oxygen partial pressure sensor made up of a transition metal oxide or rare earth metal oxide is normally disposed in a position in which the excess air ratio downstream of a flame formed by a burner can be detected and, at times of abnormality, within the flame. The resistance change of said oxygen partial pressure is detected and the combustion is stopped when incomplete combustion occurs due to oxygen depression, clogging of the primary air orifice of the burner or clogging of the combustion chamber with the products of combustion.

Abstract: A method of producing resin powder in which a resin solution prepared by dissolving a resin in a water-miscible solvent is sprayed from a nozzle while spraying water from another nozzle located close to the first-said nozzle so as to form fine emulsified droplets of said resin solution in water, then at least a substantial portion of the water-miscible solvent in said emulsified droplets is rapidly transferred into water to produce a suspension of resin powder. The suspension is then filtered. Apparatus for practicing this method is also provided.