Experimental Investigation On The Conditions Producing Calcium Dihydrogenphosphate Granules With A Spray Fluidized Bed

The ways of making calcium dihydrogenphosphate include the wet-process andthe dry-process. The first method have many disadvantages such as complexequipments, high. energy consumption, granulation inhomogmeous. Producingcalcium dihydrogenphosphate granules with a spray fluidized bed can shorten theprocess route, reduce the energy consume, improvement of product quality. Atheoretical analysis and experimental study of experimental investigation on theconditions producing calcium dihydrogenphosphate granules with a spray fluidizedbed has an important guiding meaning for this production process.On the basis of literature and the purpose and conditions of the experiment,draw up the process route of the experiment, accomplished the design and debuggingof the devices. For the experiment, adopting the twin-fluid atomizer atomize thecalcium dihydrogenphosphate, do the experimental research of calciumdihydrogenphosphate granules with a spray fluidized bed, conducted to study theeffect of the spray density, the temperature of the fluidized bed layer, and the gasvelocity.The experimental results indicate that:(1) The two different granule results in the experiment were investigated. It waspossible that they were formed in different growth mechanism, ie the layer type mechanism and the agglomeration mechanism. Under the certain operation condition,the grain mainly is grow up with the layer type mechanism, the end grain takesoriginal grain as a basic son grain, the formation of the shape and is close by theoriginal grain son. Changing the operation condition, then the grain mainly is grow upwith the agglomeration mechanism, then the end grain is started a grain of son byseveral beginnings to glue knot together through a solid bridge, shows irregular form.(2) The spray density, the temperature of the fluidized bed layer have greateffect on the granular velocity and the growth mechanism. When the bed temperaturebelow 87℃and the spray density above 4.78ml/(m².s), the average granular diameterincreased rapidly, mainly in agglomeration mechanism. On the coutrany, mainly inlayer type mechanism.(3) In the experimental range, the fluidizing gas velocity (0.5～0.75rn/s) haslittle effect on the experimente result.(4) According the result of experiment, presented the sketch map of dividedregion of manipulation.Base on the law of energy conservation, a correction to the model according tothe experimental results was made so that the predictions by the model have a goodagreement with those from the experiment.d_i=d₀·((p₁·v₁·c₁·p_s)/(m·p_h)·t+1)^1/3...