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Wang H.,Zhejiang University of Technology | Mu J.,Zhejiang University of Technology | Su M.,Linde Engineering Hangzhou Co. | Zheng S.,Zhejiang University of Technology | And 2 more authors.
Applied Mechanics and Materials | Year: 2012

The paper studies the relationship between axial force and breadth of back blade by numerical simulation and experiment. On the basis of the RNG k-ε turbulence model and technology of compact local grids and regional computing, three dimensional numerical simulations to 100HZ165-250 centrifugal pump with various breadths were carried out. Through comparing and analyzing of the flow field, it can be seen that the axial force reduces with the increase of the back blade breadth. After that, the simulation results were verified by the experimental data got from different test devices, and it shows that the conclusions are reliable. © (2012) Trans Tech Publications, Switzerland.

Xia M.,Tianjin University | Xin Y.,Tianjin University | Luo J.,Tianjin University | Li W.,Tianjin University | And 3 more authors.
Industrial and Engineering Chemistry Research | Year: 2013

In our previous work, the extractive dividing-wall column (EDWC) was proved to be a promising energy-saving method for methylal/methanol azeotrope separation because it offered about an 8.3% energy saving over the corresponding conventional extractive distillation columns. We also have explored two effective composition control structures for the stabilization of the EDWC previously. However, the composition control needs online composition analyzers which are usually expensive, require high maintenance, and introduce large lags. Therefore, it is highly desirable to avoid the use of composition analyzers to economically gain this energy-saving potential. In this work, the use of temperature control instead of composition control for the EDWC process is investigated to overcome the above drawbacks. Several control structures are developed on the basis of singular value decomposition (SVD) analysis. Two temperature control structures with an adjustable vapor split are proposed first. Dynamic simulations show that the structure can handle feed disturbances effectively, except for 20% changes in methanol or water concentrations. Then, a differential temperature control is further developed. Dynamic simulations demonstrate that this structure reduces the offsets in methanol product purities. Moreover, several group comparisons of dynamic responses are demonstrated to confirm the feasibility and superiority of temperature control for stabilizing the EDWC process. © 2013 American Chemical Society.

Yang Z.-H.,Zhejiang University of Technology | Zhang Y.,Linde Engineering Hangzhou Co. | Wu J.,Zhejiang University of Technology | Chen J.-M.,Zhejiang University of Technology | And 2 more authors.
Gao Xiao Hua Xue Gong Cheng Xue Bao/Journal of Chemical Engineering of Chinese Universities | Year: 2011

Polypropylene (PP), polysulfone (PS) and polyethersulfone (PES) hollow fiber membranes were used as novel structured packings, respectively, in contactors for iso-propanol/water distillation. In the contactor, the liquid flows through the lumens of fibers, and the vapor flows counter currently outside the fibers. Results indicate that all the contactors with above three kinds of membranes separately have higher separation efficiency than the distillation column with traditional packings. The HTU values of above hollow fibers could attain to the range of 8~10 cm. The sequence of separation efficiency for above three membrane contactors is PES > PP > PS and their overall mass transfer coefficients are 0.0026, 0.0020 and 0.0019 cm · s-1, respectively. All contactors with above hollow fiber membranes can operate normally under the gas velocity above the flooding limit of conventional packing column, which presents great advantage in hydraulics performance and separation efficiency. Further analyses with Hansen solubility parameters and micro-structure show that PES and PP structured packing have better operation stability than PS.

Lai C.,Zhejiang University of Technology | Zhang G.,Zhejiang University of Technology | Sheng X.,Linde Engineering Hangzhou Co. | Sun H.,Zhejiang University of Technology | And 2 more authors.
Advanced Materials Research | Year: 2011

Novel membrane contactors offer a number of important advantages over conventional dispersed phase contactors, including absence of emulsions, no flooding at high flow rates, no unloading at low flow rates, no density difference between fluids required, and surprisingly high interfacial area. Based on the former work of our group, this paper provides a general review of recent progress in the application of hollow fiber membrane contactors in liquid/liquid and gas/liquid separation and in the environmental waste treatment including VOCs and CO2 separation, metal ion recovery, and alcohol purification. © (2011) Trans Tech Publications, Switzerland.

Wang L.,Zhejiang University of Technology | Sheng X.,Linde Engineering Hangzhou Co. | Zhang G.,Zhejiang University of Technology | Zuo W.,Zhejiang University of Technology
Proceedings - International Conference on Computer Distributed Control and Intelligent Environmental Monitoring, CDCIEM 2011 | Year: 2011

Textile industry is producing large amounts of wastewater heavily colored with high loading of inorganic salts. Two kinds of composite reverse osmosis membranes aimed for advanced treatment of textile dyeing wastewater were investigated, which made up an effective hybrid membrane separation coupled with coagulation-flocculation, microfiltration(MF)-uItrafiltration (UF) and reverse osmosis (RO) dual membrane processes. At first, effect of membrane materials on practical treatment efficiency was discussed and performance of different membrane separation as well as quality of permeates used for industrial recycling was compared. Since ultrafiltration combined with coagulation as pretreatment for RO/NF process can remove most turbidity, the rejection for COD and salts in integrated RO membrane process could reach as high as 94% and 97%, respectively. The permeate flux of CPA2 was larger than BW30, but its anti-fouling ability was less than that of BW30. All final RO permeates were colorless, and had a fairly good quality to exceed the Water Quality Standard for Industrial Water Consumption (GB/T 19923-2005) of China, which showed feasibility of integrated membrane process application in industrial textile wastewater reutilization. © 2011 IEEE.

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