METHOD FOR CONTROLLING COMBUSTION IN INDUSTRIAL FURNACE

摘要

PURPOSE:To considerably reduce NOX generated by combustion by measuring the oxygen concentration of the air for combustion and the velocity of the flow by means of a device for analyzing air for combustion provided between a burner and a valve for regulating the supply of air for combustion. CONSTITUTION:Into each of separate ducts 3 at a position between the burner and the valve, a device 21 for analyzing air for combustion is inserted through the duct wall. The device 21 for analyzing air for combustion is equipped with a probe for an oxygen sensor for measuring the oxygen concentration of the air for combustion, a gaseous object for the measurement, and with a probe for a flow-rate sensor for measuring the quantity of the flow of the gaseous object for the measurement. The oxygen sensor 45 outputs a voltage correspond ing to the oxygen concentration of the air for combustion; the voltage is processed by an O2-computing element 121 and supplied to a Wet/Dry conversion device 125 whereby the measurement value determined in terms of a concentra tion of wet oxygen containing moisture is converted to a value in terms of a concentration of dry oxygen containing no moisture. The dry air value thus obtained is outputted to a control device, which executes a feed-forward control according to the dry air value.