JPS5680629A - Safety device for combusting apparatus - Google Patents

Abstract

PURPOSE:To prevent the occurrence of incomplete combustion of fuel and to reduce the amount of CO produced immediately before occurrence of incomplete combustion, by providing a means for detecting elongation of flame and stopping combustion of fuel in response to the detection signal. CONSTITUTION:CO removing catalyst 2 is disposed at the outlet of a heat exchanger, and a by- pass pipe 6 extended from a combustion chamber 5 is provided downwardly of the catalyst 2. Further, a pipe 4 having outlet ports 3 is connected to the by-pass pipe 6, and a detecting element 15 is provided in the pipe 6. One open end 10 of the pipe 6 is extended into the combustion chamber 5. With such an arrangement, when the amount of oxygen and air necessary for combustion of fuel, flame 23 is elongated to a position 24 shown by the dotted line in the drawing and closes the open end 10 of pipe 6. In this state, combustion gas having a higher temperature is supplied to the by-pass pipe 6, so that the catalyst 2 is heated to a higher temperature and enhances its CO removing function. On the other hand, high-temperature gas during combustion or after combustion is passed through the pipe 6, and O2 is not detected by the detecting element 15, so that there is produced a difference in the density of O2 as compared with that during normal combustion of fuel. Through detection of the difference, a gas valve 20 is closed by an electric circuit 18 for stopping the combustion of fuel.