Automatic distillation method and system based on solution saturation temperature and pressure relationship

Abstract

The invention discloses an automatic distillation method based on a solution saturation temperature and pressure relationship. The method comprises the following steps: S1, adopting a physical property calculation method according to a vapor pressure equation provided in a 'petrochemical engineering basic data manual' and a 'vapor pressure and temperature relationship table of a solution in a solvent manual' (version 3) and 'a practical solvent manual', establishing a relationship between the saturated vapor pressure of the selected solvent and the temperature of the selected solvent, and establishing a mathematical model p = f (t); S2, continuously acquiring vapor pressure data or vapor temperature data of the solvent selected in the rotary evaporator or the reaction kettle by using a temperature sensor or a pressure sensor; and S3, taking a saturation temperature value as a control target according to the mathematical model p = f (t) of the selected solvent, and realizing an automatic reduced pressure distillation process of the rotary evaporator or the reaction kettle through time proportion control. The distillation rate, the evaporation efficiency and the heat exchange utilization rate of a heat-carrying medium are improved; and a foam phenomenon generated by boiling of a solvent in a reactant is prevented.

Description

technical field [0001] The invention relates to the vacuum distillation control of a rotary evaporator or a reactor, in particular to an automatic distillation method and system based on the relationship between solution saturation temperature and pressure. Background technique [0002] At present, the vacuum distillation system of rotary evaporator or reactor is mostly composed of rotary evaporator or reactor, vacuum pump and cold (hot) circulation device. The decompression control method adopts manual adjustment or only one target Single-point control of the value, that is, the user checks the "relationship table between the vapor pressure of the solution and its temperature" in the relevant information according to the type of solvent selected, and selects a solution vapor pressure value (or vapor temperature value) as the steady-state control target value. However, the decompression process does not take into account the influence of the local atmospheric pressure and th...

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Problems solved by technology

However, the decompression process does not take into account the influence of the local atmospheric pressure and the influence of the solvent heating rate.

When the control target of the solution vapor temperature selected by the user is lower than the optimal value, the evaporation efficiency is low, the evaporation process is longer, and the energy consumption is large; when the control target of the vapor temperature is higher than the optimal value, there will be solvent boiling to generate foam or The phenomenon of overflow affects the effect of distillation and purification

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