| 摘要 |
PURPOSE:To properly control a combustion condition and to permit the control to be completely automatic by detecting combustion noises made in combustion in order to judge the combustion condition according to the frequency characteristic or composite sound-pressure level. CONSTITUTION:Combustion noises detected by a sound-pressure probe 9 installed to a furnace 30 are converted into an electric signal in a sound-pressure detector 11, and transmitted to a noize meter 12, in which the sound-pressure level is measured, and the sound-pressure spectrum is obtained in a spectrum analyzer 14. The output is processed in an arithmetic unit 15 to obtain a fixed control signal, and the arithmetic unit calculates the composite sound-pressure level in a specified frequency-band, or the ratio of the specified frequency-band to the whole composite sound-pressure. The operation result is compared with a setting value in a sound-pressure level-indicating controller 16, and an air flow-rate control valve 20 is so controlled that the deviation becomes zero, by controlling, for example, an air flow-rate-indicating controller 19 through a ratio-setting unit 18. |
