Destilacion General

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

 

 

 

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