液-液混合的机理主要有层流混合和湍流混合。对于高黏度液体(黏度在10

The main mechanisms of liquid-liquid mixing are laminar mixing and turbulent mixing. For high-viscosity liquids (viscosity above 10 Pa·s), the mixing process is usually laminar mixing. For most chemical production processes, the viscosity of liquid materials is relatively low, generally below 10 Pa. s. At this time, mixing is often achieved through strong turbulence between fluids [2]. The mechanism of turbulent mixing is more complicated. Generally speaking, when two fluids meet, the following mixing process will occur: <br>(1) In the initial stage of macro-mixing, there are large eddies in the liquid due to turbulence. As the mixing process progresses, the larger eddies are subjected to turbulent stretching and shearing, and the material transfers through the interchange positions, and at the same time the energy is transferred from the large eddies to the small eddies. From the observation scale larger than the size of the vortex, the uniformity of the macroscopic concentration is achieved. On a scale smaller than the size of the vortex, no obvious mixing occurs. <br>(2) Mesoscopic mixing means that the small vortex is further deformed and divided into smaller clusters under the further action of the turbulent stretching and shearing force, until the smaller scale, namely the Kolmogorov [3] scale cluster. However, these mixtures still maintain a high degree of separation at the molecular level inside the Kolmogorov-scale micelles. On this scale, small vortices become Kolmogorov-scale clusters mainly through two ways: vortex fragmentation and vortex diffusion. Through these two effects, the unevenness of the mixture is reduced to the size of the vortex itself.<br>(3) Micro-mixing Micro-mixing refers to mixing on the molecular scale. When the size of the vortex micelles is small enough, molecular diffusion takes effect within a short distance, resulting in a random distribution of molecular scales in the mixture. At this time, the mixture has reached a high degree of homogeneity at the molecular level. Baldyga [4] believed that when the spatial scale of the vortex cluster reaches the Kolmogorov scale, the vortex cluster will entrain the surrounding fluid to form a short-lived tubular vortex structure. The fluid flow inside the tubular vortex structure is laminar flow, and the molecules diffuse between different laminar fluids. For the mixing process between low-viscosity small molecule (or medium molecule) fluids, the time scale of forming a tubular vortex structure is generally larger than the time scale of molecular diffusion, which becomes the main factor to control the liquid-liquid micro-mixing. The mixing process of the above three scales is carried out sequentially from a general perspective, but to a certain extent, it is also carried out at the same time. The time scale of the entire mixing process needs to consider the mixing process of the above three scales comprehensively.

The mechanism of liquid-liquid mixing mainly includes laminar mixing and turbulent mixing. For high viscosity liquids (viscosity above 10 Pa · s), the mixing process is usually laminar mixing. For most chemical production processes, the viscosity of liquid materials is relatively low, generally at 10Pa Below s, mixing is often achieved through strong turbulence between fluids [2]. The mechanism of turbulent mixing is complex. Generally speaking, when two streams of fluids meet, the following mixing process will occur:<br>(1) Macro mixing at the initial stage of mixing, there is a large vortex in the liquid due to the turbulence. With the progress of the mixing process, the large vortex transfers material through the exchange position under the action of turbulence tension and shear, and the energy is transferred from the large vortex to the small vortex. From the observation scale larger than the vortex size, the uniformity of macro concentration is achieved There is no obvious mixing on the scale of smaller vortex size.<br>(2) Mesoscopic mixing, i.e. small vortex, under the further action of turbulent tension and shear force, the vortex further deforms and divides into smaller micro clusters to a smaller scale, i.e. Kolmogorov [3] Scale micelles. However, these mixtures still maintain a high degree of separation at the molecular level within Kolmogorov scale micro clusters. On this scale, small vortices become Kolmogorov scale micro clusters mainly through] two ways: vortex fragmentation and vortex diffusion. Through these two effects, the non-uniformity of the mixture is reduced to the size of the vortex itself.<br>(3) Micromixing micromixing refers to mixing on the molecular scale. When the size of vortex micro clusters is small enough, molecular diffusion acts in a short distance, resulting in the mixture reaching the random distribution of molecular scale. At this time, the mixture reaches a high degree of homogeneity at the molecular level. Baldyga [4] When the spatial scale of vortex micro cluster reaches Kolmogorov scale, vortex micro cluster will suck up the surrounding fluid and form a short tubular vortex structure. In the tubular vortex structure, the flow of fluid is laminar flow, and molecules diffuse between different laminar fluids. For the mixing process between low viscosity small molecule (or medium molecule) fluids, the time scale of forming tubular vortex structure is generally larger than that of molecular diffusion, which has become the main factor controlling liquid-liquid micromixing. In general, the mixing processes of the above three scales are carried out successively, but they are also carried out at the same time to a certain extent. The time scale of the whole mixing process needs to comprehensively consider the mixing processes of the above three scales.

The mechanism of liquid-liquid mixing mainly includes laminar mixing and turbulent mixing. The mixing process between high viscosity liquids (viscosity above 10 Pa· s) is usually laminar mixing. For most chemical production processes, the viscosity of liquid materials is relatively low, generally below 10 pa.s. At this time, mixing is often realized by strong turbulence between fluids [2]. The mechanism of turbulent mixing is complicated. Generally speaking, when two streams of fluids meet, the following mixing process will occur: (1) Macro-mixing At the initial stage of mixing, there is a large vortex inside the liquid due to turbulence. With the mixing process going on, the larger vortex will transfer material by exchanging positions under the action of turbulent stretching and shearing, and at the same time, energy will be transferred from the large vortex to the small vortex. From the observation scale larger than the vortex size, the macroscopic concentration uniformity is achieved. On the scale smaller than the vortex size, there is no obvious mixing. (2) Mesoscopic mixing, that is, under the further action of turbulent stretching and shearing force, the vortex is further deformed and divided into smaller micro-clusters, until the smaller scale, that is, Kolmogorov[3] scale micro-clusters. However, these mixtures remain highly separated in Kolmogorov-scale micelles at the molecular level. On this scale, small vortices are transformed into Kolmogorov-scale micro-clusters mainly through two ways: vortex fragmentation and vortex diffusion. Through these two actions, the degree of inhomogeneity of the mixture is reduced to the size of the vortex itself. (3) Micro-mixing Micro-mixing refers to the mixing on the molecular scale. When the size of vortex micelles is small enough, molecular diffusion works in a short distance, resulting in the mixture reaching the random distribution of molecular scale. At this time, the mixture has reached a high degree of homogeneity at the molecular level. Baldyga[4] and others think that when the spatial scale of the vortex micro-cluster reaches Kolmogorov scale, the vortex micro-cluster will suck the surrounding fluid and form a short tubular vortex structure. In the tubular vortex structure, the fluid flow is laminar flow, and molecules are diffused among different layered fluids. For the mixing process between low viscosity small molecular (or medium molecular) fluids, the time scale of forming tubular vortex structure is generally larger than that of molecular diffusion, which becomes the main factor to control the micro-mixing of liquid and liquid. Generally speaking, the mixing process of the above three scales is carried out sequentially, but to a certain extent, it is also carried out at the same time, and the time scale of the whole mixing process needs to comprehensively consider the mixing process of the above three scales.