Abstract: Reforming reactor is the key equipment of continuous reforming unit. In the reactor, the contact between the gas and solid phases is a cross flow contact. The abnormal phenomena cavity and pinning could occur if the gas flow is large enough, which may greatly restrict the operating flexibility and affect the safe and stable operation of the reactor. Acoustic emission technology was used to detect the reactor under cold operation. The acoustic emission data of different operation states of the reactor were compared and analyzedso as to determine in time whether the above-mentioned abnormal phenomena occurred or not.The experimental results showed that the waveform was stable during normal operation of the reactor and the average signal level was 20 dB; the amplitude was 35~45 dB. The waveform displayed pulse shape when the reactor was abnormal. When cavity appeared, the average signal level was 20~35 dB; the amplitude was 35~55 dB and the characteristic frequency was 25~150 kHz. When pinning appeared, the average signal level was 30~60 dB; the amplitude was 35~75 dB and the characteristic frequency was 25~250 kHz. The waveform, characteristic parameters and power spectrum of the signal changed obviously when the flow state of the catalyst changed. By using multiple sensors, the fault could be located and the fault type could be identified. The above results indicate that as a non-invasive measurement technology, acoustic emission technology can effectively detect the operation state of the continuous reforming reactor and can provide technical support for the long-term safe and stable operation of the device.

Key words: reforming reactor, gas-solid flow, acoustic emission, cavity, pinning, fault diagnosis