Patent ID: 6237368
Filing Date: 2001-05-29
Classification: B01D,C03B,G05D,Y10S

Abstract:
A method of regulating or controlling the content of NO.sub.x in exhaust gases released from a denitrating plant associated with the operation of glass-melting furnaces with several burners which are operated in alternation, wherein the setpoint of the content of NO.sub.x, NO.sub.x set, is supplied to a multiplier (2), at the same time the content of O.sub.2 in the released gas, O.sub.2 act, is measured continuously, and the content of O.sub.2 detected in a first transducer (3), O.sub.2 act', is likewise supplied to the multiplier (2), and in the multiplier (2) a standardization of the setpoint NO.sub.x set into a standardized setpoint NO.sub.x set n is effected, where the following applies for the standardization: ##EQU3##and where the standardized setpoint NO.sub.x set n is compared with the content of NO.sub.x in the released gas detected by a second transducer (6), NO.sub.x ', the deviation xd resulting from this comparison is supplied to a regulator (4), which adapts an amount of NH.sub.3 to be supplied to the denitrating plant (5) as a correcting variable y for reacting with and regulating the content of NO.sub.x as regulating variable, and where both the beginning of a combustion break FP.sup.+ and the end of a combustion break FP.sup.- are each supplied as a signal to a binary signal generator (8), which with a time delay supplies the signals as time-delayed beginning of a combustion break FP.sub.z.sup.+ or as time-delayed end of a combustion break FP.sub.z.sup.- to the regulator (4), which interrupts the regulation upon receipt of the signal FP.sub.z.sup.+ and adjusts the amount of NH.sub.3 to a lower constant fixed value F1 via a control, the amount of NO.sub.x in the released gas detected by the second transducer (6), NO.sub.x ', is supplied to a memory element (7), transformed there into a higher constant fixed value F2 as amount of NH.sub.3, and is likewise supplied to the regulator (4), and where, as soon as the regulator (4) has received the signal FP.sub.z.sup.-, the fixed value F1 is adjusted to the fixed value F2 via a control, whereafter the regulation is continued immediately.