The secondary steam from the evaporator is compressed by the compressor, the pressure and temperature rise, the enthalpy increase, and then sent to the heating chamber of the evaporator as heating steam, so that the material liquid is maintained in a boiling state, and the heating steam itself is condensed into water. In this way, the original steam to be discarded has been fully utilized, the latent heat has been recovered, and the thermal efficiency has been improved, and the economy of the steam is equivalent to 30 effects of multi-effect evaporation. The whole evaporation system does not need to be supplemented with steam during normal operation.
In an MVR falling film evaporator, liquid and steam flow downward and in parallel. The feed liquid is preheated to boiling temperature by the preheater, and a uniform liquid film is formed through the liquid distribution device at the top into the heating tube, and part of the tube evaporates.
Secondary steam and concentrated liquid flow down the tube. The residence time of the feed liquid in the evaporator is short, which can adapt to the evaporation of the heat sensitive solution. In addition, falling film evaporation is also suitable for high viscosity solutions, with a viscosity range of 0.05 to 0.4Pas. Falling film evaporator is easy to burst the foam in the tube, so it is also suitable for the evaporation of foaming materials.
Because falling film evaporator is liquid film heat transfer, so its heat transfer coefficient is higher than other forms of evaporator; In addition, falling film evaporation has no liquid column static pressure, and the heat transfer temperature difference is significantly higher than other forms of evaporator. Therefore, it is desirable to have good heat transfer effect and minimum one-time investment, which is the preferred evaporator form of the owner.

(1) Short residence time, will not cause degradation of heat-sensitive materials.
(2) Due to the film flow, the heat transfer coefficient K value is relatively large.
(3) The pressure drop is small, so the pressure and temperature on the process side of the heat exchanger are nearly constant.
(4) Because the process fluid flows under the action of gravity, rather than driven by the temperature difference, it allows a more economical low temperature difference.
(5) The boiling is convective boiling, so the state of the heat exchange tube surface has little influence on the boiling.
(6) MVR technology coupled falling film evaporator compared with the traditional three-effect evaporator, can save 60-70% of the energy cost.