Cooling of Granules in Vibrating, Suspended Bed: Engineering Simulation

摘要

Here we suggest an algorithm for calculation of the process parameters and design of a vertical cooler with inclined, gas-permeable blades and with a vibrating, suspended layer of granules on them (Vibrating Fluidized Bed—VFB). The algorithm is based on the use of the equations of heat and material balance, taking into account the influx of moisture into the layer with cold air and dust—as a carryover. Mode entrainment of dust particles and moisture from the VFB is described by using empirical formulas and Π-theorem. To calculate the cooling time of granules a model of the dynamics of a variable mass VFB was built, which linked the geometrical and physical process parameters to a single dependency. An example showed that mass flow of granules of 248 kg/h and a volume flow of air of 646 m3/h with temperature of 30℃ to cool the zeolite granules from 110℃ to 42℃ for 49 s required a vertical apparatus of rectangular shape with four chambers and with volume of 0.2 m3. A comparative analysis of technological parameters of the projected cooler with the parameters of typical industrial apparatuses showed that for all indicators: the cooling time of granules, the flow rate of gas (air) and the heat flow, a 4-chambered, vertical apparatus of rectangular shape with VFB was the most effective.