Investigation of extraction fraction in confined impinging jet reactors for tri-butyl-phosphate extracting butyric acid process

The extraction fraction E and overall volumetric mass transfer coefficient kka of TBP extracting butyric acid pro- cess in confined impinging jet reactors （CIJR） with two jets were investigated. The main variables tested were the concentration of tri-butyl-phosphate （TBP） and butyric acid, the impinging velocity V, the impinging velocityratio of two phases Vorg/Vaq, the nozzle inner diameter di and the distance L between the jet axes and the top wall of the impinging chamber. The results showed that E and kLa increase with an increase of the impinging velocity V, the concentration ofTBP Corg, and the impinging velocity ratio Vor/Vaq. However, E and kta decrease with an increase of the inner diameter d1 from 1 to 2 mm, the concentration of butyric acid Caq from 0.5% （v/v） to 2% （v/v）. The factor L ranging from 3 to 11 mm has a negligible effect on E and kLa. A correlation on these variables and kLa was proposed based on the experimental data. These results indicated good mass transfer oerformance of CIJR in the extraction operation.

Theoretical analysis of fluid mixing time in liquid-continuous impinging streams reactor

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.

Micromixing efficiency in a T-shaped confined impinging jet reactor

Confined impinging jet reactor(CIJR)offers advantages for chemical rapid processes and has become an important new reactor used in the chemical industry.The micromixing efficiency in a T-shaped CIJR for two tubes of inner diameter of 3 mm was studied by using a parallel competing iodide–iodate reaction as the working system.In this work,the effects of different operating conditions,such as impinging velocity and acid concentration,on segregation index were investigated.In addition,the effects of the inner nozzles diameter and the distance L between the jet axis and the top wall of the mixing chamber on the micromixing efficiency were also considered.It is concluded that the best range of L in this CIJR is 6.5–12.5 mm.Based on the incorporation model,the estimated minimum micromixing time tmof CIJR approximately equals to 2×10-4s.These experimental results indicate clearly that CIJR possesses a much better micromixing performance compared with the conventional stirred tank(micromixing time of 2×10-3to 2×10-2s).Hence,it can be envisioned that CIJR has more promising applications in various industrial processes.

Characterization of micro-mixing in a novel impinging streams reactor

This paper presents an experimental investiga-tion of a novel impinging stream reactor(ISR)with the aim of high mixing intensity.The integral mixing quality in the reactor was measured with the iodide-iodate reaction and showed excellent mixing performance.The impact of the operating parameters,such asfluxes,circulation and inter-nozzle distances,was investigated in terms of segregation index.The results showed that the increase offlux,the decrease of inter-nozzle distance and a suitable circulation can improve the micro-mixing efficiency.Based on turbulence theory,it was estimated that the characteristic micro-mixing time was 0.002–0.02 s,which was much shorter than that in the stirred tank reactor.The micro-mixing time was related to the segregation index,which was in good agreement with those in the literature.

Residence time distribution and modeling of the liquid phase in an impinging stream reactor

Based on some experimental investigations of liquid phase residence time distribution(RTD)in an impinging stream reactor,a two-dimensional plug-flow dispersion model for predicting the liquid phase RTD in the reactor was proposed.The calculation results of the model can be in good agreement with the experimental RTD under different operating conditions.The axial liquid dispersion coefficient increases monotonously with the increasing liquid flux,but is almost independent of gas flux.As the liquid flux and the gas flux increase,the liquid dispersion coefficient of center-to-wall decreases.The axial liquid dispersion coefficient is much larger than that of center-to-wall,which indicates that the liquid RTD is dominated mainly by axial liquid dispersion in the impinging stream reactor.