Study On Effect Mechanism Of Parallel Inclined Plates In Liquid-Solid Fluidized Bed

In terms of current issues for the limitations of the traditional liquid-solid fluidized bed including ineffective treatment of refractory materials and insufficient handling capacity, the advantages, such as high separation precision and large settlement area, of many inclined plate settling devices at home and abroad were introduced. A new idea for the sake of improving separation effect by the combination of fluidization effect and inclined settlement action was proposed. The mechanism effect of parallel inclined plates for the mineral particle settlement, separation and yield improvement was expounded from the view of particle motion dynamics in liquid-solid fluidized bed.The paper was based on free settling process of single particle. The movement theoretical relationship among particle property, equipment dimension and rising water velocity was built by methodology combination of vector calculation, theoretical derivation and geometric application, which describes the movement law of single phase sedimentation, two-phase separation and critical state. The suitable equipment model was designed and the test system was established to verify the model.For the first time, a new thinking was presented to describe the motion law by analyzing the velocity vector of a single particle. The motion model for single phase particle in inclined plates channels, ,was proposed. Then experimental verification was arranged by different size of ballotini(0.2-0.4mm,0.4-0.6mm,0.6-0.8mm) and magnetite(0.2-0.3mm,0.3-0.5mm). Results indicate that the theoretical values are agree with the experimental data,and the model has better predication performance on the densier or larger particle, especially when the rising velocity is low. The experiment with different feed rate was carried out to modify the model by hindered settling principle and the new model wasFurthermore, theoretical model of bi-phase particles settling simultaneously was deduced including the difference expression of motion trace, the utilization coefficient, and separation efficiency. The trajectory deviation was put forward to explain effect of inclined plates in liquid-solid fluidized bed for separation accuracy improvement.Through the test and analysis Lpd becomes larger with the increase of the feed speed and water rate. While the k and η value get greater with the decrease of water velocity and the increase of feed rate. By and large the k value is about 2.5-8 and η value is about 70-90%.Moreover, through the research of the critical particles in the inclined plates channels, the theoretical expression of treatment advantage, was derived after adding the inclined plates. Meanwhile the particle critical condition,, and settling efficiency,,were set up. Different kinds of tests were conducted, which found that the critical water velocity and e value decreases with the increase of the feed rate. As a result, the UL/U0 value on critical state is up to 2.5 and e value generally between 0.45-0.7 in feed case of 50-200 g.From the point of movement track by experimental and theoretical analysis, the effect mechanism of parallel inclined plates for capacity enlargement and accuracy improvement in liquid-solid fluidized bed have been described qualitatively and quantitatively. The research results are of certain theoretical significance and practical value for industrial inclined plate channel structure design and operation conditions.