Falling film evaporation process for evaporation materials through feed pump from the top falling film evaporator, evaporation tube (monitor), the material through the cloth membrane in membrane distribution in the heat exchange tube, when material with gravity flow lumen is outside of the tube steam heating, evaporation after reaching evaporating temperature, material together with the secondary steam from the tube in the form of thin film evaporation.
The shell side heat transfer heat steam into the falling film evaporator.
The shell side of the falling film evaporator has a baffle plate, guide the secondary steam, condensation and discharge can not be condensed gas.
And in this process the heat through the wall from the gaiden to pipe domestic evaporation materials, through heat after secondary steam condensed water is falling film evaporator outside.
The characteristics of falling film evaporation system:
1) falling film evaporator of material liquid from the top of the evaporator, along the tube wall under the gravity into a membrane, and in the process to add thick, concentrate at the bottom.
Falling film evaporator can be low evaporation concentration, viscosity smaller (for example, within the range of 0.05 ~ 0.45 Ns/m2) of the material.
2) due to the solution of the membrane flow in single type evaporator, heat transfer coefficient is higher.
3) stay time is short, not easy to cause the material deterioration, suitable for heat-sensitive materials processing.
4) small amount of fluid retention and falling film evaporator can be according to the energy supply, vacuum degree, and the concentration of the feed rate of change and quickly.
Only 5) due to the process fluid flow under the gravity, rather than by high temperature difference, you can use the evaporation temperature difference.
6) falling film evaporator is suitable for evaporation and concentration, foam materials due to the material liquid into membrane evaporation in the heating tube, which form the gas-liquid separation, in effect at the bottom of the body at the same time, most of the material liquid is siphoned off, only a small portion of material liquid separated from the secondary steam enters the separator to strengthen, the whole process of material liquid forming no too big impact, to avoid the formation of bubbles.
