Experimental Investigation Of Drying Paste Material Utilizing Vibrating Fluidized Bed With Inner Heat And Inert Particles

Many techniques for drying the paste materials in industry, such as the belt drying and sprayer drying, are of enormous infrastructure, insufficient contact between gas and fluid, inferiority of heat and mass transfer and low heat efficiency. Fluidized bed with inert particles based method is one of the attractive approaches. However, the need heat of the process was all offered by the hot air, which results in huge vent heat lose and low heat efficiency. The dosage of air shall be reduced and the power consume be descended by introducing inner heat into the bed to provide the needed heat; furthermore, the heat and mass transfer shall be strengthened and gobbets be broken up by introducing machine vibration. Accordingly, these two improvements are considered in the fluidized bed with inert particles in our work, and the drying process is proposed, and moreover, the experiment research about the improvements is also included for drying paste materials.A set of VFB with inner heat and inert particles was designed for drying paste materials with the beading as the inert particles. And three aspects experiments are carried out. Firstly, in the hydrodynamics characteristic experiment, the bed pressure drop descended because of the vibration, and the minimum fluidized velocity raised when the inert particles' diameter and the height of still bed increased. Secondly, in the heat transfer experiment, the results indicated that the heat transfer coefficient between the fluidized beds and immersed tubes descended with the inert particles' diameter and increased with fluidized gas velocity and vibration frequency at the beginning, then turn to steady; when the gas velocity was 1.6m/s and the vibration frequency was 14.5H, the heat transfer coefficient can get the most data. Finally, the relationship between intensify index for volume heat transfer coefficient and the various operating factors was investigated.In the aspect of model investigation, a criteria connection formula about the volume heat transfer coefficient which is important for engineering magnify were obtained with dimensional analysis method and went out on contrast and demonstration with experiment data. The result proved that they can inosculate commendably.At last, a pilot-scale device was designed according the results of the lab experiments and the research based this device was achieved the anticipative result. Through experiment demonstration and model analysis, proving that it is feasible to use vibrating fluidized bed with inner heat and vibration for drying paste material and this kind of equipment has certain economic and applied value.