Distillation/evaporation processes:
1) Separate or undilute solutions (mixtures) based on the different volatilities of the components.
Limit of atmospheric operation:
2) thermal sensitivity, decomposition under boiling temperature.
Solution: Different kinds of vacuum distillation.
Evolution steps of vacuum distillers, evaporators
1) Distillation below 1 mbar
2) Low temperature: gentle handling (max. 250 °C)
3) No thermal decomposition
4) Vertical, polished evaporator surface
5) Internal cooler
6) Roller wiper
7) Expensive technique
*0 Reactories quimicos
Falling Film Evaporator
Wiped Film Evaporators
Roller-wiper system
1) Vertical and horizontal mixing
2) Very thin film (<1 mm)
3) Optimal heat transfer
4) Low mechanical gear (lightweight)
5) Material
6) Fiber-glass reinforced PTFE
7) Graphite
8) Self-cleaning ability
Heating, cooling
1) Use of preheater
2) Heat recovery ?
3) External steam-heated coat (Thermal sheet)
4) Heated pumps and product outlets
The Condenser
1) Main part of vacuum formation (regulation).
2) Condensation just above melting temperature.
3) Theoretical optimum not feasible
4) Problem of freezing product: multiple parallel evaporators
5) Leakage
Vacuum System
1) Only to evacuate non condensable gases.
2) Generally consists of Roots-blowers and diffusion pumps.
Scale up process steps:
| Laboratory | Pilot | Industrial |
|---|---|---|
| 1) After computer simulation 2) Borosilicate glass 3) Visual observation 4) Feasibility studies 5) 0,02 m2 evaporator surface 6) 0,1-0,8 kg/h feed rate 7) Computer aided
|
1) Stainless steel 2) 0,06 m2 evaporator surface 3) Feed rate: 3-9 kg/h 4) Often took over by manufacturer
|
1) Residence time: maximum 20 s 2) Evaporator surface: 50 m2 3) 11,6 m high 2 m diameter 4) 5000 kg/h capacity
|
Scale up – big industrial
1) Residence time: maximum 20
2) Evaporator surface: 0,3-50
3) 11,6 m high 2 m diameter
4) 30-5000 kg/h capacity
| Atm distillation | Vacuum Distillation | Film Evaporator | Short-path Distillation | Molecular Distillation | |
|---|---|---|---|---|---|
| Operation Pressure(Pa) Residence Time(s)
Use Cases |
105 4000 Petroleum Industry Laboratory Industry |
103 3000 Petroleum Industry Laboratory Industry Heat sensitive materials |
102 25 Pharmaceutical Industry Oil Production Food Industry Chemical Industry |
0,1 10 Lanolin Cleaning Fish Oil Butter Pepper oil Vitamins Silicone Oils Alcohols |
10-2 1 Plastic Softeners Vacuum Oil Separation of fatty acids Separation of dyes |