Research on the erosion analysis of continuous slag discharge pressure reducing devices in high-pressure gasifiers

High-pressure differential liquid-solid two-phase flow is widely used in the chemical industry, energy, and power fields. In this study, a multistage segmental throttling orifice pressure-reducing pipe was developed to address the bridging risk and erosion challenges associated with batch slag discharge in coal gasification. Ultrasonic technology was used to evaluate the erosion distribution inside the pipe and to establish the erosion mechanism. The research results demonstrate a rapid increase in the pressure drop of the pressure-reducing pipe with a rising flow rate, indicating its high-pressure drop characteristics. However, after the experiment was conducted for 30 h, the pipe failed at 5.56 m3/h operating conditions and the pressure drop performance of the pressure-reducing pipe was significantly decreased as erosion time increased. The pipe structure experiences severe deformation, expansion, and formation of pits due to impact, which exacerbated erosion and led to more complex erosion behavior.