振动流化床浸没水平管传热特性研究

Study on heat transfer characteristics in an aerated vibrated fluidized bed with inner-heating tubes

为了深入研究振动流化床浸没水平管的传热特性,分别以沙子和玉米细颗粒作为实验物料,用水平探头测定了振动流化床中这2种床层颗粒与浸没水平管间的传热系数,分析了操作气速、振动频率、空气进口温度等因素对传热过程的影响。结果表明:在低气速下,振动是影响振动流化床中传热的主要因素,振动的引入可以明显改善流化作用,可以在低气速下得到较好的传热效果,同时达到节能的效果。通过分析实验结果,建立了振动流化床的传热关联式,模型计算值与实测值能较好吻合。研究结果可为干燥膏状物料时确定适宜的操作参数提供参考。

In order to get a further study of the heat transfer characteristics in an aerated vibrated fluidized bed with inner-heating tubes, the heat transfer coefficients were measured with a horizontal gauging rod. The heat transfer coefficients of a horizontal tube immersed in an aerated vibrated fluidized bed was investigated by using sand and corn particles as experimental materials. The effects of operating gas velocity, vibration frequency and air inlet temperature on heat transfer were studied. The test results indicate that the vibration is the key factor affecting the heat transfer in the case of lower gas velocity. By vibrating the effect of the fluidization can be intensified and good heat transfer performance is obtained, and also energy saving can be realized. The heat transfer correlation in the aerated vibrated fluidized bed was established. The model agreed well with the measured data. The research provides the experimental basis for the design of proper operating parameters in drying process of paste materials.