棉籽和蓖麻籽的冷榨试验与数值模拟

Cold pressing experiment and numerical simulation of cottonseed and castor bean

探讨棉籽和蓖麻籽植物油料的冷榨应力-应变关系、应力-压缩比关系以及加载速率对应力-应变关系和应力-压缩比关系的影响,探讨临界压榨压力选取问题。进行了棉籽和蓖麻籽冷榨试验,采用川北方程建立双曲线型应力-应变模型和压缩比的理论计算模型。研究表明,加载速率对油料破碎应力、应变以及应力-应变关系有影响,速率越大,破碎应力和应变越大;棉籽和蓖麻籽的模拟结果与实测值比较吻合。根据压缩比变化率及其斜率曲线近似确定出棉籽和蓖麻籽工程临界压榨压力分别为70 MPa和100 MPa。

The experiments of cold pressing of cottonseed and castor bean were carried out to study the stress-strain relationship and the stress-compression ratio relationship. The effects of rate of applied pressure on the stress-strain relationship and the stress- compression ratio relationship were investigated. The methods of identification of critical pressing pressure were proposed. Hyperbolic stress-strain model and calculative model of compression ratio of oil plant were developed on the basis of the Kawakita＇s Equation. The results of the experiments indicate that effects of rate of applied pressure on the broken stress and strain and stress-strain relationship are obvious, the broken stress and strain increase with increasing rate of applied pressure. The simulated results of cottonseed and castor bean coincide with those from experiments. By using of variation rate and slope curves of realistic compression ratio, 70 MPa and 100 MPa are defined as the critical pressing pressure of cottonseed and castor bean respectively.