Based on the double-flow model, a three-dimensional mathematical model of multiphase flow in RH system has been developed to predict the flow field and gas holdup distribution. Also, the circulation flow rate was measured with the water model. The results show that the nozzle blockage layers have small influence on circulation flow rate, while the effect of the blockage modalities and numbers is significant. Under the interaction of blockage modalities and numbers, the gas holdup distribution is the key factor to determine the circulation flow rate. Symmetrical blockage is an acceptable modality under the condition of a small amount of blockage, but the effect of non-symmetrical blockage on circulation flow rate is more obvious. If the blockage number is more than 3, the up-snorkel must be promptly treated or replaced.

RH degasser is an efficient way of degassing in producing high quality products. Moreover, ultrasonic degassing has also been proven to be a reasonably efficient way of degassing. In this paper, an experimental equipment similar to RH degasser combined with ultrasound was built. Parametric studies have been carried out to assess the effectiveness of ultrasonic degassing and to explore the possibility of using ultrasonic vibration to accelerate the degassing process in RH degasser. The results indicate that the degassing process can be accelerated by the use of ultrasound, and makes the RH degassing more efficient.

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