Continuous homogenous azeotropic distillation(CHAD) and pressure-swing distillation(PSD) are explored to separate a minimum-boiling azeotropic system of ethyl acetate and n-hexane. The CHAD process with acetone as the...Continuous homogenous azeotropic distillation(CHAD) and pressure-swing distillation(PSD) are explored to separate a minimum-boiling azeotropic system of ethyl acetate and n-hexane. The CHAD process with acetone as the entrainer and the PSD process with the pressures of 0.1 MPa and 0.6 MPa in two columns are designed and simulated by Aspen Plus. The operating conditions of the two processes are optimized via a sequential modular approach to obtain the minimum total annual cost(TAC). The computational results show that the partially heat integrated pressure-swing distillation(HIPSD) has reduced in the energy cost and TAC by 40.79% and 35.94%, respectively, than the conventional PSD, and has more greatly reduced the energy cost and TAC by 62.61% and 49.26% respectively compared with the CHAD process. The comparison of CHAD process and partially HIPSD process illustrates that the partially HIPSD has more advantages in averting the product pollution, energy saving, and economy.展开更多
Ordinary columns of jet grouting are circular or fan-shaped. But in recent years, such shapes as candy-shaped columns were put to practical use. They are constructed by switching the rotational speed of the stem in on...Ordinary columns of jet grouting are circular or fan-shaped. But in recent years, such shapes as candy-shaped columns were put to practical use. They are constructed by switching the rotational speed of the stem in one rotation. We applied this method to swing jet grouting. That is, we changed the rotational speeds in the swing jet grouting to make elongated columns near rectangle. The test construction was succeeded and the columns’ shapes conformed to those designed. In addition, the quality was confirmed to be as good as ordinary columns. Radii （distances from center to outer ends） were 1.03 to 1.21 times as large as those designed. Improvement ratios were 95% or more in any position. Strengths were varied by location, but they satisfied design strength 1.5 kN/m2 at any position. We concluded that this new column can be applied to practice in the same way as ordinary columns.展开更多
基金Supported by the Education Foundation of Chongqing(KJ1712307)the Application Technology Research and Developments Foundation of Fuling Technology Board(FLKJ,2016ABA1026)the Young Foundation of Yangtze Normal University(2015XJXM03)
文摘Continuous homogenous azeotropic distillation(CHAD) and pressure-swing distillation(PSD) are explored to separate a minimum-boiling azeotropic system of ethyl acetate and n-hexane. The CHAD process with acetone as the entrainer and the PSD process with the pressures of 0.1 MPa and 0.6 MPa in two columns are designed and simulated by Aspen Plus. The operating conditions of the two processes are optimized via a sequential modular approach to obtain the minimum total annual cost(TAC). The computational results show that the partially heat integrated pressure-swing distillation(HIPSD) has reduced in the energy cost and TAC by 40.79% and 35.94%, respectively, than the conventional PSD, and has more greatly reduced the energy cost and TAC by 62.61% and 49.26% respectively compared with the CHAD process. The comparison of CHAD process and partially HIPSD process illustrates that the partially HIPSD has more advantages in averting the product pollution, energy saving, and economy.
文摘Ordinary columns of jet grouting are circular or fan-shaped. But in recent years, such shapes as candy-shaped columns were put to practical use. They are constructed by switching the rotational speed of the stem in one rotation. We applied this method to swing jet grouting. That is, we changed the rotational speeds in the swing jet grouting to make elongated columns near rectangle. The test construction was succeeded and the columns’ shapes conformed to those designed. In addition, the quality was confirmed to be as good as ordinary columns. Radii （distances from center to outer ends） were 1.03 to 1.21 times as large as those designed. Improvement ratios were 95% or more in any position. Strengths were varied by location, but they satisfied design strength 1.5 kN/m2 at any position. We concluded that this new column can be applied to practice in the same way as ordinary columns.
