生物多孔材料干燥过程中组织非稳态收缩

Transient Shrinkage of Tissue of Bio-porous Material during Dehydration

根据颗粒体积收缩和平均湿度的变化规律,提出了生物多孔材料干燥组织非稳态收缩的递推模型。利用该模型对40℃热空气干燥下的豌豆各单元层边界半径变化、收缩位移及各层组织的收缩量变化进行了计算。计算结果表明:豌豆在干燥过程中随着湿分的对外迁移、湿度降低,豌豆组织收缩并不是由外向内同步收缩,而是先失去水分的外部先收缩,没有失水的部位不收缩。同时,与内部相比,外部失水较多,收缩幅度也较大。

A transient shrinkage model was proposed for bio-porous material on the base of the relationship between the shrinking volume and average moisture content of particle.The changes of boundary radius,shrinkage displacement and the tissue shrinkage of every element layer of the pea at 40℃ were calculated.As suggested in the result,the external of the pea firstly appeared contraction due to water loss,rather than synchronous contraction from the outside to the inside with the wet sub-external migration and humidity decrease during the drying process for the pea.There is no shrinkage of parts of no loss water.Furthermore,the external shrinked more greatly than the internal due to more water loss in the external of the pea.