Separation process of butanol-butyl acetate-methyl isobutyl ketone system by the analysis to residual curve and the double effect pressure-swing distillation

The separation of ternary mixture of butanol, butyl acetate, and methyl isobutyl ketone(MIBK) was initially analyzed by the residual curve. In this process, MIBK was chosen as the azeotropic agent during the first step of separation. The optimum mass ratio of extra MIBK was 1.6 in the modified feed stream according to the residual curve. Thus on this condition the top product was butanol-MIBK azeotrope while the bottom product was butyl acetate in the preliminary separation of the mixture. Then the butanol and MIBK azeotrope was separated by the double effect pressureswing distillation with the low pressure column performing at 30 kPa and the atmospheric pressure column at 101 kPa. The optimal operating conditions were then obtained by using Aspen Plus to simulate and optimize the process. The results showed that the mass purities of butanol, butyl acetate, and MIBK were all more than 99% and reached the design requirements. Additionally, compared with the traditional distillation with outside heating, the double effect pressure swing distillation saved the reboiler duty by 48.6% and the condenser duty by 44.6%.

Sliding Mode Control Approach for Electrically Controllable Clutch of AMT Based on the Feedback Linearization

A sliding mode control approach based on the feedback linearization is proposed for the electrically controllable clutch of AMT vehicles. The nonlinear dynamic model for the hydraulic actuator associated with clutch is established. By means of the exact feedback linearization procedure of differential geometry, an equivalent, fully controllable and linear model is derived via a homomorphic transformation for the AMT clutch system.Furthermore, a sliding mode control is introduced to improve robustness. The tracking tests are performed using the sliding mode control on a Santana LX passenger car, and the experimental results prove that this nonlinear controller is of fine robustness and high degree of tracking accuracy.

Safe Distance for Inspection of 1 000 kV UHVAC Lines with Helicopter

Helicopter inspection of ultra high voltage （UHV） transmission lines has unmatched advantages compared to manual work due to the inspection angle and high-tech equipment on board, especially in detailed inspections of tower heads and defect-detections in virtue of infrared/ultraviolet techniques. This paper deals with some key technical problems in the inspections of i 000 kV UHVAC lines with a helicopter, such as the safe distance of live-line working, electromagnetic field intensity and flight control. Based on the study results, a set of UHV line inspection methods was worked out and applied to the inspection of live UHV lines.

Modified k-ω model using kinematic vorticity for corner separation in compressor cascades

A new method of modifying the conventional k-w turbulence model for comer separation is proposed in this paper. The production term in the w equation is modified using kinematic vorticity considering fluid rotation and deformation in complex geometric boundary conditions. The corner separation flow in linear compressor cascades is calculated using the original k-w model, the modified k-w model and the Reynolds stress model （RSM）. The numerical results of the modified model are compared with the available experimental data, as well as the corresponding results of the original k-w model and RSM. In terms of accuracy, the modified model, which significantly improves the performance of the original k-w model for predicting comer separation, is quite competitive with the RSM. However, the modified model, which has considerably lower computational cost is more robust than the RSM.

The effect of symmetry potential on the balance energy of light particles emitted from mass symmetric heavy-ion collisions with isotopes,isobars and isotones

Using the Ultrarelativistic Quantum Molecular Dynamics(UrQMD) model,the balance energies of free neutrons,free protons and Z=1 particles(including free protons,deuterons and tritons) from mass symmetric heavy-ion collisions with isotopes,isobars and isotones are studied.The influence of nuclear symmetry potential energy on the balance energy is emphasized.It is found that the balance energy of free neutrons is sensitive to the nuclear symmetry energy,while that of free protons is not.Particularly,the initial neutron/proton ratio dependence of the balance energy of free neutrons from Sn isotopes can be taken as a useful probe to constrain the stiffness of the nuclear symmetry energy.