The novel SiC foam valve tray was made of thin slices of SiC foam material with a high specific surfacearea. Hydrodynamic performances of the novel SiC foam valve tray were studied with air-water system at atmos-pheri...The novel SiC foam valve tray was made of thin slices of SiC foam material with a high specific surfacearea. Hydrodynamic performances of the novel SiC foam valve tray were studied with air-water system at atmos-pheric pressure. These performance parameters included pressure drop, entrainment, weeping and clear liquidheight. The mass transfer efficiency of the SiC foam valve tray was measured in laboratory plate column. Comparedwith the F1 float valve tray, the dry pressure drop was decreased about 25%, the entrainment rate was about 70%lower at high gas load, the weeping was much better, and the mass transfer efficiency was far higher. Thus, theoverall performance of the novel SiC foam valve tray was better than that of F1 float valve tray.展开更多
A real-time sensing of the molecular distillation process temperature by a FLUKE brand thermograph Ti50 IR FlexCam and thermography technique was realized. After completion of the molecular distillation, three propert...A real-time sensing of the molecular distillation process temperature by a FLUKE brand thermograph Ti50 IR FlexCam and thermography technique was realized. After completion of the molecular distillation, three properties of heat transport chain cuts and residues obtained in the process were estimated by Differential Scanning Calorimetry （DSC） （specific heat, enthalpy, thermal conductivity）. These properties are of great importance for improving oil characterization and for future modeling and simulation of the molecular distillation process. The results show that through the method of Differential Scanning Calorimetry, profiles have been obtained from the variation of specific heat, enthalpy and thermal condutivity as a function of temperature for samples of cuts from the distillation （ASTM D-2892） and fractions of distillate and residue from the process of molecular distillation.展开更多
This article describes the experimental results obtained by the solar distiller by specifying the radiative properties of materials, the analysis of various types of losses in the system and the establishment of the e...This article describes the experimental results obtained by the solar distiller by specifying the radiative properties of materials, the analysis of various types of losses in the system and the establishment of the energy assessment of the system being the main question to consider. The experiment was undertaken in Tlemcen-Algeria by working out a solar distiller in order to measure the various temperatures of the system. Salt was added to study the negotiable effect of the salinity of water on solar distillation and it is noted that the production of distilled water decreases with salinity. The distiller is forwarded to a constant global solar flow. Experimental results obtained in heat transfer of natural convection in the pure and simultaneous heat and mass transfer, proven that these phenomena are in the boundary layer. This enables people to admit that the existence of a stagnant zone inside of distiller is called the ＂buffer zones＂.展开更多
Distillation column control is widely explored in literature due to its complexity and importance in chemical and petrochemical industries. In this process, pressure represents one of the most important variables to b...Distillation column control is widely explored in literature due to its complexity and importance in chemical and petrochemical industries. In this process, pressure represents one of the most important variables to be controlled. However, there are few studies about how pressure affects the dynamic behavior of distillation columns and most research on distillation column control involve direct manipulation of cooling fluid through the condenser. Nevertheless, such an approach demands constant changes in cooling fluid flowrates that are commonly by the order of tons per hour, which can be difficult to work or even unfeasible in a real plant. Furthermore, this strategy is usually avoided, as it can cause fouling and corrosion acceleration. The hot-vapor bypass strategy fits well as a solution for these issues, eliminating the need to dynamically manipulate cooling fluid flowrates in the condensation unit. This work presents the modeling and simulation of a conventional distillation column for the separation of water and ethanol, in which a comparative study between a conventional pressure control and a control using hot-vapor bypass was performed. The main results were obtained through dynamic simulations which considered various disturbances in the feed stream, and demonstrated superior performance by the hot-vapor bypass system over the usual scheme proposed in literature, while evaluating the lntegral Absolute Error （IAE） norm as the control performance index.展开更多
In order to investigate the effect of priming on Chickpea seed performance under drought stress, a study was carried out at the Seed Research Laboratory of Razi University, Kermanshah, Iran. The experiment was a facto...In order to investigate the effect of priming on Chickpea seed performance under drought stress, a study was carried out at the Seed Research Laboratory of Razi University, Kermanshah, Iran. The experiment was a factorial with three factors arranged in a completely randomized design with four replications. The first factor was seed priming （control （untreated）, HB-101 （Completely organic herbal extracts, derived from the bark of dark cones）, KNO3 and distilled water）, the second was drought stress levels （0.0, -0.3, -0.6, -0.9, -1.2 MPa） and the third was chickpea cultivars （Arman and Azar）. Results indicated that for both cultivars germination percentage （GP）, mean germination rate （MGR）, radicle length （RL）, plumule length （PL） and seedling dry weight （SDW） were reduced when drought stress level were increased from 0 to -!.2 Mpa, although, the cultivars showed different responses to the increased drought stress level. For all of the traits under study, the best results due to the priming treatments were obtained at the drought stress levels higher than -0.6 or -0.9 MPa. So that, at the -1.2 MPa of drought stress level, GP, MGR, and SDW were increased 53.75, 0.49, and 13.85, respectively by HB -101 when compared with control. However, seeds primed with HB-101 showed better performance than those primed with distilled water and KNO3. In general, this study revealed that seed priming especially with HB-101 improved chickpea seed performance under drought stress condition. However, the improvements were more obvious at the higher levels of drought stress.展开更多
基金Supported by the National Basic Research Program of China （2009CB219905） National Natural Science Foundation of China（21176172）+1 种基金 National Key Technology R＆D Program （2011BAE03B07） Program for Changjiang Scholars and Innovative Research Team in University （IRT0936） The authors are also grateful to Institute of Metal, Chinese Academy of Science for providing SiC foam elements, and their support and discussions.
文摘The novel SiC foam valve tray was made of thin slices of SiC foam material with a high specific surfacearea. Hydrodynamic performances of the novel SiC foam valve tray were studied with air-water system at atmos-pheric pressure. These performance parameters included pressure drop, entrainment, weeping and clear liquidheight. The mass transfer efficiency of the SiC foam valve tray was measured in laboratory plate column. Comparedwith the F1 float valve tray, the dry pressure drop was decreased about 25%, the entrainment rate was about 70%lower at high gas load, the weeping was much better, and the mass transfer efficiency was far higher. Thus, theoverall performance of the novel SiC foam valve tray was better than that of F1 float valve tray.
文摘A real-time sensing of the molecular distillation process temperature by a FLUKE brand thermograph Ti50 IR FlexCam and thermography technique was realized. After completion of the molecular distillation, three properties of heat transport chain cuts and residues obtained in the process were estimated by Differential Scanning Calorimetry （DSC） （specific heat, enthalpy, thermal conductivity）. These properties are of great importance for improving oil characterization and for future modeling and simulation of the molecular distillation process. The results show that through the method of Differential Scanning Calorimetry, profiles have been obtained from the variation of specific heat, enthalpy and thermal condutivity as a function of temperature for samples of cuts from the distillation （ASTM D-2892） and fractions of distillate and residue from the process of molecular distillation.
文摘This article describes the experimental results obtained by the solar distiller by specifying the radiative properties of materials, the analysis of various types of losses in the system and the establishment of the energy assessment of the system being the main question to consider. The experiment was undertaken in Tlemcen-Algeria by working out a solar distiller in order to measure the various temperatures of the system. Salt was added to study the negotiable effect of the salinity of water on solar distillation and it is noted that the production of distilled water decreases with salinity. The distiller is forwarded to a constant global solar flow. Experimental results obtained in heat transfer of natural convection in the pure and simultaneous heat and mass transfer, proven that these phenomena are in the boundary layer. This enables people to admit that the existence of a stagnant zone inside of distiller is called the ＂buffer zones＂.
基金the Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq)for financial support for this work
文摘Distillation column control is widely explored in literature due to its complexity and importance in chemical and petrochemical industries. In this process, pressure represents one of the most important variables to be controlled. However, there are few studies about how pressure affects the dynamic behavior of distillation columns and most research on distillation column control involve direct manipulation of cooling fluid through the condenser. Nevertheless, such an approach demands constant changes in cooling fluid flowrates that are commonly by the order of tons per hour, which can be difficult to work or even unfeasible in a real plant. Furthermore, this strategy is usually avoided, as it can cause fouling and corrosion acceleration. The hot-vapor bypass strategy fits well as a solution for these issues, eliminating the need to dynamically manipulate cooling fluid flowrates in the condensation unit. This work presents the modeling and simulation of a conventional distillation column for the separation of water and ethanol, in which a comparative study between a conventional pressure control and a control using hot-vapor bypass was performed. The main results were obtained through dynamic simulations which considered various disturbances in the feed stream, and demonstrated superior performance by the hot-vapor bypass system over the usual scheme proposed in literature, while evaluating the lntegral Absolute Error （IAE） norm as the control performance index.
文摘In order to investigate the effect of priming on Chickpea seed performance under drought stress, a study was carried out at the Seed Research Laboratory of Razi University, Kermanshah, Iran. The experiment was a factorial with three factors arranged in a completely randomized design with four replications. The first factor was seed priming （control （untreated）, HB-101 （Completely organic herbal extracts, derived from the bark of dark cones）, KNO3 and distilled water）, the second was drought stress levels （0.0, -0.3, -0.6, -0.9, -1.2 MPa） and the third was chickpea cultivars （Arman and Azar）. Results indicated that for both cultivars germination percentage （GP）, mean germination rate （MGR）, radicle length （RL）, plumule length （PL） and seedling dry weight （SDW） were reduced when drought stress level were increased from 0 to -!.2 Mpa, although, the cultivars showed different responses to the increased drought stress level. For all of the traits under study, the best results due to the priming treatments were obtained at the drought stress levels higher than -0.6 or -0.9 MPa. So that, at the -1.2 MPa of drought stress level, GP, MGR, and SDW were increased 53.75, 0.49, and 13.85, respectively by HB -101 when compared with control. However, seeds primed with HB-101 showed better performance than those primed with distilled water and KNO3. In general, this study revealed that seed priming especially with HB-101 improved chickpea seed performance under drought stress condition. However, the improvements were more obvious at the higher levels of drought stress.
