Micromixing in the submerged circulative impinging stream reactor (SCISR) developed by the authors is investigated with the Bourne's reaction scheme. The values measured for the impinging velocity, u0, under the ...Micromixing in the submerged circulative impinging stream reactor (SCISR) developed by the authors is investigated with the Bourne's reaction scheme. The values measured for the impinging velocity, u0, under the conditions of SCISR normal operation, only is of the order of 0.1m·s^-1, are much slower than that inferred,suggesting low power requirement for operation. The values of the characteristic time constant for micromixing,tM, determined in the impinging velocity range of 0.184m·s^-1 < u0 < 0.326m·s^-1 are ranged from 192ms to 87 ms, showing that impinging streams promotes micromixing very efficiently. The data follow approximately the relationship of tM∝ u0^-1.5. A comparative study shows that the micromixing performance of SCISR is much better than that of the traditional stirred tank reactor. The tM values predicted with the existing theoretical model are systematically longer than those measured by about 2--3 times, implying that the regularity of impinging streams promoting micromixing is unclear yet.展开更多
The mixing time of impact zone in liquid-continuous impinging streams reactor(LISR) is theoretically calculated by empirical model and modern micromixing model of the fluid mixing process, and the variation laws of ma...The mixing time of impact zone in liquid-continuous impinging streams reactor(LISR) is theoretically calculated by empirical model and modern micromixing model of the fluid mixing process, and the variation laws of macromixing time and micromixing time are quantitatively discussed. The results show that under a continuous and stable operating condition, as the paddle speed increases, the macromixing time and micromixing time calculated by the two models both decrease, even in a linkage equilibrium state. Simultaneously, as the paddle speed increases, the results figured by the two models tend to be consistent. It indicates that two models both are more suitable for calculation of mixing time in high paddle speed. Compared with the existing experimental results of this type of reactor, the mixing time computed in the speed of 1500 r/min is closer to it. These conclusions can provide an important reference for systematically studying the strengthening mechanism of LISR under continuous mixing conditions.展开更多
The elution of WO ions by NaOH. NaNO3 NaCl and NH4Cl on strong basicanion exchange resins in quaternary ammonium form I and the adsorption properties after elution were studied. In addition, the elution curse, the per...The elution of WO ions by NaOH. NaNO3 NaCl and NH4Cl on strong basicanion exchange resins in quaternary ammonium form I and the adsorption properties after elution were studied. In addition, the elution curse, the permeation curveand the exchange capacities of operation were presented. The eluate containingtungsten with high content and excessive eluant of low content were obtained by employing the process of eluting using mixed solution of NaCl and NaOH. It's possible to obtain Na2WO4. 2H2O with high purity by evaporating and crystallizing theeluate. The results of mixed elution showed that the diffusion coefficients of Cl-.OH- and WO ions in solution or exchange agent varied due to the coexistence ofcounter ions and then the exchange velocity of WO→Cl- and WOe→OH- wasaccelerated.展开更多
基金Supported by the National Natural Science Foundation of China (No. 29276260, No. 20176043).
文摘Micromixing in the submerged circulative impinging stream reactor (SCISR) developed by the authors is investigated with the Bourne's reaction scheme. The values measured for the impinging velocity, u0, under the conditions of SCISR normal operation, only is of the order of 0.1m·s^-1, are much slower than that inferred,suggesting low power requirement for operation. The values of the characteristic time constant for micromixing,tM, determined in the impinging velocity range of 0.184m·s^-1 < u0 < 0.326m·s^-1 are ranged from 192ms to 87 ms, showing that impinging streams promotes micromixing very efficiently. The data follow approximately the relationship of tM∝ u0^-1.5. A comparative study shows that the micromixing performance of SCISR is much better than that of the traditional stirred tank reactor. The tM values predicted with the existing theoretical model are systematically longer than those measured by about 2--3 times, implying that the regularity of impinging streams promoting micromixing is unclear yet.
基金Project(51276131)supported by the National Natural Science Foundation of ChinaProject(ZRZ0316)supported by the Natural Science Foundation of Hubei Province,ChinaProject(2013070104010025)supported by the Morning Glory Project of Wuhan Science and Technology Bureau,China
文摘The mixing time of impact zone in liquid-continuous impinging streams reactor(LISR) is theoretically calculated by empirical model and modern micromixing model of the fluid mixing process, and the variation laws of macromixing time and micromixing time are quantitatively discussed. The results show that under a continuous and stable operating condition, as the paddle speed increases, the macromixing time and micromixing time calculated by the two models both decrease, even in a linkage equilibrium state. Simultaneously, as the paddle speed increases, the results figured by the two models tend to be consistent. It indicates that two models both are more suitable for calculation of mixing time in high paddle speed. Compared with the existing experimental results of this type of reactor, the mixing time computed in the speed of 1500 r/min is closer to it. These conclusions can provide an important reference for systematically studying the strengthening mechanism of LISR under continuous mixing conditions.
文摘The elution of WO ions by NaOH. NaNO3 NaCl and NH4Cl on strong basicanion exchange resins in quaternary ammonium form I and the adsorption properties after elution were studied. In addition, the elution curse, the permeation curveand the exchange capacities of operation were presented. The eluate containingtungsten with high content and excessive eluant of low content were obtained by employing the process of eluting using mixed solution of NaCl and NaOH. It's possible to obtain Na2WO4. 2H2O with high purity by evaporating and crystallizing theeluate. The results of mixed elution showed that the diffusion coefficients of Cl-.OH- and WO ions in solution or exchange agent varied due to the coexistence ofcounter ions and then the exchange velocity of WO→Cl- and WOe→OH- wasaccelerated.
