Visualization research on ash deposition characteristics of Zhundong coal in a vertical liquid slagging cyclone furnace

Abstract

A 300 kW vertical liquid slagging cyclone furnace is built for the combustion experiment of Hami coal(HM), a kind of Zhundong coal. The sampling probe and CCD camera are used to monitor the growth process of deposition in the furnace online. In addition, the slags at various positions of the furnace are collected and analyzed to study the metal migration law and slagging characteristics of HM during combustion in the furnace. The results show that compared with the traditional furnace, deposition thickness on the probe of the liquid slagging cyclone furnace is much smaller. The stable thickness of the deposition on probes 1 and 2 is 0.85 mm and 3.30 mm respectively. Fe2O3 shows enrichment in liquid slag. The alkali metals in the gas phase condensed on the low-temperature surface of the sampling probe and existed in the initial layer of the deposition. The SO3 reacts with alkaline oxides at low temperature to form viscous compounds such as Na2SO4 and CaSO4. Due to the fast cooling rate, almost no diffraction peaks can be observed in the XRD curves of the liquid slag and glass filaments, which indicates that the material is a completely amorphous solid.