liquid phase

The liquid phase refers to the portion of a substance system that is in a liquid state. In this phase, the molecules are close together but can move against each other. The liquid is stable in terms of volume but unstable in terms of shape. It takes on the shape of the container in which it is located but retains its volume.

In multiphase systems (e.g. solid–liquid–gas), the term "liquid phase" is used to distinguish the liquid component from solid particles or a gas phase. Examples of this are suspensions (solid particles in a liquid phase), emulsions (droplets of one liquid phase in another liquid phase) or liquid-gas systems (foam, bubble columns). The physical properties of the liquid phase – such as density, viscosity, surface tension, solubility and diffusion coefficients – influence mass transport, flow behaviour and reaction kinetics in such systems.

In process engineering equipment such as stirred tanks, columns or reactors, the liquid phase is often regarded as a continuous phase in which other phases (gas bubbles, solid particles or droplets) are present. The design of agitators, pumps, nozzles or heat exchangers is largely based on the properties of the liquid phase, such as viscosity (laminar/turbulent), the difference in density compared to other phases and surface tension (bubble or droplet size, coalescence behaviour). Evaporation processes can be carried out efficiently in amixon® devices. The liquid is added continuously at the rate at which evaporation takes place. This keeps the fill level constant as the concentration increases. The suspension/solution is then gently dried under vacuum and discharged as a powder.