Successfully reported this slideshow.
Your SlideShare is downloading. ×

Evaporation.pptx

Ad
Ad
Ad
Ad
Ad
Ad
Ad
Ad
Ad
Ad
Ad
Upcoming SlideShare
Clustering-dendogram.pptx
Clustering-dendogram.pptx
Loading in …3
×

Check these out next

1 of 22 Ad

Evaporation.pptx

Download to read offline

Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science o

Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporationv Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science of Evaporation Science o

Advertisement
Advertisement

More Related Content

Recently uploaded (20)

Advertisement

Evaporation.pptx

  1. 1. Evaporation Submitted By- Rajat Uppal (16110040) Sunil Kumar (16110049)
  2. 2. INDEX  What is Evaporation?  Types of Evaporation.  Factors affecting evaporation.  Types of Evaporators:- • Climbing film • Falling Film • Forced Circulation • Natural Circulation
  3. 3. Evaporation means simply vaporization from the surface of a liquid below its boiling point. Thus, no boiling occurs and the rate of vaporization depends on the diffusion of vapour through the boundary layers above the liquid. EVAPORATION
  4. 4. When heat applied in solution the motion of molecules increase and molecules present in the surface overcome the surface tension of the liquid and it evaporates because surface molecules have less cohesive force than others. MECHANISM
  5. 5.  Concentration – With inc in conc-->Crystal formation  Clogging of tubes  Foaming – Foam causes heavy entrainment by accompanying vapors.  Temperature Sensitivity- High Temp Damage (Food)  Scale- Some soln deposits scales on heating reducing overall coff. Of evaporation.  Material of Construction – Soln can react with the material of evaporator. FACTORS AFFECTING THE EVAPORATION
  6. 6. Other properties to be considered are-: Specific Heat Heat of Concentration Toxicity Radioactivity Explosion hazards OTHER FACTORS
  7. 7. • Equipments which are used for evaporation are called Evaporators. Types of Evaporator: 1. Natural circulation evaporator 2. Forced circulation evaporator. 3. Film evaporators(Climbing film & Falling film) EVAPORATORS
  8. 8. • Working principle: • The movement of the liquid results from convection currents set up by the heating process. • Convection currents: The process in which heat moves through a gas or liquid as the hotter parts rises and the cooler part sinks. NATURAL CIRCULATION EVAPORATORS
  9. 9. DIAGRAM
  10. 10. 1) They are simple, easy and cheap to construct. 2) They are easy to use and clean. 3) Stirring of the evaporating liquids can be done easily. ADVANTAGES
  11. 11. 1)The whole of the liquid is heated all the time which may lead to decomposition of the components. 2)On the evaporating surface foam is rapidly formed which decreases evaporation. Solids may be deposited at the bottom which make the stirring necessary. 3)This pan can only be used for evaporating aqueous and thermostable liquid extracts. 4)They can not be used for evaporating extracts containing organic solvents like alcohol etc. DISADVANTAGES
  12. 12.  Construction: • The evaporator consists of a short tube calendria and a large cylindrical vessel (body of the evaporator) for separation of vapor and liquid takes place. • The liquor inlet is provided at the side of the cylindrical vessel. • A pump is fitted in between the calendria and the body of the evaporator. • A tangential inlet for liquid under high pressure is placed at neck of the body of the evaporator. • The vapor outlet is placed at the top of the body and it may be passed through a condenser to collect the condensed liquid. FORCED CIRCULATION EVAPORATORS
  13. 13. DIAGRAM
  14. 14. 1)These have an great advantage over natural circulation evaporators in that the rapid liquid movement improves heat transfer, especially with viscous liquids or materials that deposit solids or foam readily. 2)The equipment is suitable for operation under reduced pressure due to the capacity of the process to overcome the effect of greater viscosity of liquids. 3)These evaporators possess rapid evaporation rate. ADVANTAGES
  15. 15. • Corrosion-erosion can occur, due to high circulation velocities. • Salt deposits detach and accumulate at the bottom. DISADVANTAGES
  16. 16. Film evaporators spread the material as a film over the heated surface, and the vapor escapes the film. Types:- Climbing Film evaporators Falling Film evaporators FILM EVAPORATORS
  17. 17. • Working • At the upper end, the mixture of vapor and concentrated liquor enters a separator, the vapor passes to a condenser, and the concentrated liquid to a receiver. • Cold or pre heated liquor is introduced into the tube. • Heat is transferred to the liquor from the walls and boiling begins. • Ultimately sufficient vapor has been formed for the smaller bubbles to unite to a large bubble,filling the width of the tube. • As more vapor is formed, the slug of liquid is blown up the tube, the tube is filled with vapor, while the liquid continues to vaporize rapidly, the vapor escaping up the tube and, because of friction between the vapor and liquid, the film also is dragged up the tube upto a distance of 5 to 6 metres. CLIMBING FILM EVAPORATORS
  18. 18. DIAGRAM
  19. 19. Working principle • The liquor to be evaporated is introduced at the top of the evaporator tubes and the liquor comes down due to gravity. • The concentrate and vapor leaves the bottom. They are separated in a chamber where the concentrate is taken out through product outlet and vapor from vapor outlet. FALLING FILM EVAPORATORS
  20. 20. DIAGRAM
  21. 21.  Advantages: • Because of obtaining good heat transfer the method being especially useful with liquids that are too viscous to be processed in units in which the film is formed naturally.  Disadvantages: • A major disadvantage of falling film evaporators is the potential instability of the falling film • Expense to manufacture and install the instrument is high. • Difficult to clean and maintain. ADVANTAGES & DISADVANTAGES
  22. 22. THANK YOU 

×