关键词: 球团, 竖炉, 填料床, 气流, 压降

Abstract: The palletizing shaft furnace(PSF) with internal channels and drying bed is a conventional pellet roasting equipment in China. According to the principle of similitude, a cold-state experimental setup was built to study the gas flow distribution in PSF. Based on the experimental data, representative flow-net diagrams are plotted to make sure of gas flow distribution in PSF and, further, to ascertain how the operating parameters affect the gas flow distribution in PSF. Some conclusions are therefore drawn as follows. The gas flow distribution will depend on the ratio of inflow, k, if the constructional parameters of PSF are constant, if the ratio of inflow k is critical, i.e., a critical operating condition. The roasting and cooling gases will entirely flow into the roasting zone and the internal vertical air channels (internal channels for short), respectively. When starting from such a critical operating condition to increase roasting gas flow or decrease cooling gas flow, the roasting gas starts flowing downwards so as to enter inside the inner channels, and the greater the ratio k is, the larger the downward flowrate will be. On the contrary, when starting from the same condition to decrease roasting gas flow or increase cooling gas flow, the cooling gas starts flowing upwards so as to enter into the roasting zone, and the smaller the ratio k is, the larger the upward flowrate will be. However, in the two cases as above-mentioned, there will be only one which is possible to take place at the same time, otherwise both are impossible.