SlideShare a Scribd company logo
1 of 20
EVAPORATION:
18ch17
CONTENTS;
• Evaporation process
• Objectives of evaporation
• Evaporation equipment (Evaporator)
• Parts of evaporator
• Problems occurring in evaporator
• Types of evaporator
• Potential hazards
• Environmental applications of evaporator
OBJECTIVE OF EVAPORATION:
• The objective of evaporation is to concentrate a solution
consisting of a non volatile Solute and a volatile solvent.
1. Evaporation is conducted by vaporising a portion of
the solvent to produce concentrated solution of thick
liquor.
2. In evaporation the thick liquor is the valuable
product and the vapours are condensed and
discarded.
EVAPORATION DIFFERS FROM OTHER
OPERATIONS
1. Evaporation
VS
1. Drying
2. Distillation
3. Crystallization
4. Water distillation ( large scale evaporation)
EVAPORATOR;
• An evaporator is a device
used in a process to turn
the liquid form of a
chemical substance such
as water into its gaseous-
form/vapor.
COMPONENTS OF AN EVAPORATOR:
1. Thermoexpansion Valve (TEV):Meters refrigerant flow and converts
hot high pressure liquid to a cold low-pressure liquid.
2. Differential Pressure Switch: Monitors the cleanliness of the air filter
3. Evaporator Coil: Absorbs heat through the vaporization of low-pressure liquid.
4. Low-Pressure Cut Out Switch: Shuts off compressor when pressure drops
from 27.3 psi.
5. EMI Filter and EMI Gasket: Dissipates and prevents EMI from affecting the
operation of other electronic equipment located within close proximity.
6. Handle: Allows two people to lift evaporator assembly.
7. Terminal Board, Single Row: Allows for ease of troubleshooting and repair.
8. Condensate Drain Pan: Collects condensation from coil and discharges
through drain hole.
9. Evaporator Fan Motor: Drives evaporator housing fan.
10.Evaporator Fan Housing: Draws air across evaporator coil to increase
PROBLEMS
The practical solution of evaporation problems is profoundly effected by
character of the liquor is to be concentrated. It is the wide variation in liquor
characteristics which demands experience and judgement in designing and
evaporator . Some of the most important properties of the evaporatong liquid
are as follows.
1. Concentration: On evaporation the concentration of solution increases. The
density and viscosity increases with solid content until the liquor becomes
more viscous for adequate heat transfer. Continued boiling of saturated
solution causes crystals to form; these must be removed or the tubes clog.
2. Foaming: Some materials specially inorganic substances foam during evaporation.
A stable foam accompanies the vapour out of the evaporator, causing heavy
entertainment. In extreme cases the entire mass of the liquid may boil into vapour
outlet and be lost.
CONTINUE...
3. Temperature Sensitivity: Many fine chemicals, Pharmaceutical products,
foods are damaged when heated to moderate temperatures for relatively short
times. In concentrating such materials special techniques are needed to reduce
both the temperature of liquid and the time of heating.
4. Scale: Some solutions deposit scale on the heating surface. The overall
coefficient then diminishes until the evaporator may shut down and the tubes
cleaned. When the scale is hard and insoluble, the cleaning is difficult and
expensive.
5. Materials of construction: Whenever possible, evaporators are made of
some kind of steel.Many solutions, however, attack ferrous metals or
contaminated by them. Special materials such as copper, nickel, stainless steel,
aluminium, impervious graphite and lead are then used. Since these materials
are expensive, high heat transfer rates becomes specially desirable to minimize
the first cost of the equipment.
TYPES OF EVAPORATORS USED TODAY
The chief types of steam heated tubler evaporator in use today are;
1. Shell and tube type
• Long-tube vertical evaporator
a. Upward flow (Rising film evaporator)
b. Downward flow (Falling film evaporator)
c. Forced circulation
2. plate type
• Agitated-film evaporator
ALSO
• Flash evaporation
• Vacuum evaporation
• Centrifugal evaporator
• Rotary evaporator
• Vapor-compression evaporator
• Evaporative cooler
• Pumpable ice technology
• Circulation evaporator
A. UPWARD FLOW (RISING FILM
EVAPORATOR):
• The liquid being evaporated is feed from the
bottom into long tubes and heated with
steam condensing on the outside of the
tube from the shell side. This is to produce
steam and vapour within the tube bringing
the liquid inside to a boil. The vapour
produced then presses the liquid against
the walls of the tubes and causes the
ascending force of this liquid. As more
vapour is formed, the centre of the tube will
have a higher velocity which forces the
remaining liquid against the tube wall
forming a thin film which moves upwards.
This phenomenon of the rising film gives
the evaporator its name.
B. DOWNWARD FLOW
(FALLING FILM
EVAPORATOR):
• In falling film evaporators, the liquid product
usually enters the evaporator at the head of
the evaporator. In the head, the product is
evenly distributed into the heating tubes. The
liquid enters the heating tube and forms a thin
film on the tube wall where it flows
downwards at boiling temperature and is
partially evaporated. In most cases, steam is
used for heating the evaporator. The product
and the vapor both flow downwards in a
parallel flow. This gravity-induced downward
movement is increasingly augmented by the
co-current vapor flow. The separation of the
concentrated product from its vapor takes
place in the lower part of the heat exchanger
C. FORCED
CIRCULATION
• Developed for processing fluids which
are fouling, scaling, and crystallizing, The
raw material liquid is circulated through
circulation pump in the heating chamber
and separation chamber at a high speed
and heated up in the heating chamber
while flashed in the separation chamber,
to achieve efficient vapour-liquid
separation.
• The high flow speed of material liquid in
the heat exchange tube can improve heat
transfer efficiency. Evaporation process
takes place in the separator instead of
the heater. Therefore, the scaling caused
by crystallization and precipitation in the
AGITATED-FILM EVAPORATOR
• The feed enters evaporator at top, tangential to
shell and gets distributed along the shell by the
distributor. The rotor blades spread the feed
evenly on the heated surface into a thin film and
further agitate the film.
• Heating medium passing through the jacket
evaporates the volatile component in feed. The
vapor generated flow counter currently to feed
and gets cleared in entrainment separator
before leaving through vapor nozzle. The
concentrate product comes out at bottom.
PERFORMANCE OF EVAPORATOR
The principal measures of performance of a steam-
heated tubler evaporator are the capacity and the
economy of the evaporator.
• Capacity is defined as number of kilograms of water vaporized per hour.
• Economy is defined as number of kilograms of water vaporized per
kilogram of stream feed to the unit.
• Steam consumptionis defined as the ratio of capacity of evaporator
to the economy of evaporator (kilograms of steam per hour).
POTENTIAL HAZARDS
OF EVAPORATOR
ENVIRONMENTAL APPLICATIONS OF EVAPORATOR
1. Brine
2. Wastewater treatment
3. Manure
4. Sludge
5. By-product from bioethanol production
6. Food and agricultural waste
7. Fruit concentrate
8. Cement industries
9. Etc.

More Related Content

What's hot

What's hot (20)

Types of Distillation & column internals
Types of Distillation & column internalsTypes of Distillation & column internals
Types of Distillation & column internals
 
Forced circulation
Forced circulationForced circulation
Forced circulation
 
Evaporators
Evaporators Evaporators
Evaporators
 
Reactive distillation
Reactive distillationReactive distillation
Reactive distillation
 
Drum Dryer
Drum DryerDrum Dryer
Drum Dryer
 
Functional Design of Heat Exchanger
Functional Design of Heat ExchangerFunctional Design of Heat Exchanger
Functional Design of Heat Exchanger
 
Evaporators
EvaporatorsEvaporators
Evaporators
 
Types of evaporators
Types of evaporatorsTypes of evaporators
Types of evaporators
 
Spray drying pre lab report ppt final
Spray drying pre lab report ppt finalSpray drying pre lab report ppt final
Spray drying pre lab report ppt final
 
Factors affecting distillation column operation
Factors affecting distillation column operationFactors affecting distillation column operation
Factors affecting distillation column operation
 
Plate heat exchanger
Plate heat exchangerPlate heat exchanger
Plate heat exchanger
 
Evaporators
EvaporatorsEvaporators
Evaporators
 
1.2 Flash distillation
1.2 Flash distillation1.2 Flash distillation
1.2 Flash distillation
 
69686364-Evaporation-Calculations.pdf
69686364-Evaporation-Calculations.pdf69686364-Evaporation-Calculations.pdf
69686364-Evaporation-Calculations.pdf
 
Heat exchanger types and application
Heat exchanger types and applicationHeat exchanger types and application
Heat exchanger types and application
 
Evaporation ppt
Evaporation pptEvaporation ppt
Evaporation ppt
 
Heat exchangers
Heat exchangersHeat exchangers
Heat exchangers
 
crude oil refining process - CDU & VDU
crude oil refining process - CDU & VDUcrude oil refining process - CDU & VDU
crude oil refining process - CDU & VDU
 
Evaporators and their methods
Evaporators and their methods Evaporators and their methods
Evaporators and their methods
 
Evaporation
EvaporationEvaporation
Evaporation
 

Similar to Evaporation process

Evaporation and Distillation
Evaporation and DistillationEvaporation and Distillation
Evaporation and DistillationDr. Samia
 
EVAPORATION DISTILLATION AND CRYSTALLIZATION.pptx
EVAPORATION DISTILLATION AND CRYSTALLIZATION.pptxEVAPORATION DISTILLATION AND CRYSTALLIZATION.pptx
EVAPORATION DISTILLATION AND CRYSTALLIZATION.pptxPurushothamKN1
 
Evaporation.pptx
Evaporation.pptxEvaporation.pptx
Evaporation.pptxANKIT915111
 
Pharmaceutical Engineering: Evaporation
Pharmaceutical Engineering: EvaporationPharmaceutical Engineering: Evaporation
Pharmaceutical Engineering: EvaporationParag Jain
 
Objectives, applications and factors on evaporation
Objectives, applications and factors on evaporationObjectives, applications and factors on evaporation
Objectives, applications and factors on evaporationAkankshaPatel55
 
5.evaporation.pptx
5.evaporation.pptx5.evaporation.pptx
5.evaporation.pptxYashThorat20
 
Evaporation - Pharmaceutical Engineering 1st
Evaporation - Pharmaceutical Engineering 1stEvaporation - Pharmaceutical Engineering 1st
Evaporation - Pharmaceutical Engineering 1stRAHUL PAL
 
Evaporation physical pharmaceutics engineering.pdf
Evaporation physical pharmaceutics engineering.pdfEvaporation physical pharmaceutics engineering.pdf
Evaporation physical pharmaceutics engineering.pdfSuraj803123
 
evaporationanddistillation.pptx
evaporationanddistillation.pptxevaporationanddistillation.pptx
evaporationanddistillation.pptxDr. Samia
 
MP5040 Lecture 5.pdf- Process engineering
MP5040 Lecture 5.pdf- Process engineeringMP5040 Lecture 5.pdf- Process engineering
MP5040 Lecture 5.pdf- Process engineeringakalankar
 
Evaporation by ankita yagnik
Evaporation by ankita yagnikEvaporation by ankita yagnik
Evaporation by ankita yagnikAnkita Yagnik
 

Similar to Evaporation process (20)

Evaporation and Distillation
Evaporation and DistillationEvaporation and Distillation
Evaporation and Distillation
 
Types of evaporators
Types of evaporatorsTypes of evaporators
Types of evaporators
 
EVAPORATION DISTILLATION AND CRYSTALLIZATION.pptx
EVAPORATION DISTILLATION AND CRYSTALLIZATION.pptxEVAPORATION DISTILLATION AND CRYSTALLIZATION.pptx
EVAPORATION DISTILLATION AND CRYSTALLIZATION.pptx
 
Evaporation.pptx
Evaporation.pptxEvaporation.pptx
Evaporation.pptx
 
Pharmaceutical Engineering: Evaporation
Pharmaceutical Engineering: EvaporationPharmaceutical Engineering: Evaporation
Pharmaceutical Engineering: Evaporation
 
Evaporation
EvaporationEvaporation
Evaporation
 
Objectives, applications and factors on evaporation
Objectives, applications and factors on evaporationObjectives, applications and factors on evaporation
Objectives, applications and factors on evaporation
 
5.evaporation.pptx
5.evaporation.pptx5.evaporation.pptx
5.evaporation.pptx
 
Evaporation
EvaporationEvaporation
Evaporation
 
evaporation
evaporationevaporation
evaporation
 
evaporation.pdf
evaporation.pdfevaporation.pdf
evaporation.pdf
 
Evaporation - Pharmaceutical Engineering 1st
Evaporation - Pharmaceutical Engineering 1stEvaporation - Pharmaceutical Engineering 1st
Evaporation - Pharmaceutical Engineering 1st
 
Types of Evaporator
Types of EvaporatorTypes of Evaporator
Types of Evaporator
 
Evaporation physical pharmaceutics engineering.pdf
Evaporation physical pharmaceutics engineering.pdfEvaporation physical pharmaceutics engineering.pdf
Evaporation physical pharmaceutics engineering.pdf
 
evaporationanddistillation.pptx
evaporationanddistillation.pptxevaporationanddistillation.pptx
evaporationanddistillation.pptx
 
MP5040 Lecture 5.pdf- Process engineering
MP5040 Lecture 5.pdf- Process engineeringMP5040 Lecture 5.pdf- Process engineering
MP5040 Lecture 5.pdf- Process engineering
 
B.pharm sem-3-Evaporation
B.pharm sem-3-EvaporationB.pharm sem-3-Evaporation
B.pharm sem-3-Evaporation
 
2 EVAPORATION.pptx
2 EVAPORATION.pptx2 EVAPORATION.pptx
2 EVAPORATION.pptx
 
Evaporation
EvaporationEvaporation
Evaporation
 
Evaporation by ankita yagnik
Evaporation by ankita yagnikEvaporation by ankita yagnik
Evaporation by ankita yagnik
 

Recently uploaded

System Simulation and Modelling with types and Event Scheduling
System Simulation and Modelling with types and Event SchedulingSystem Simulation and Modelling with types and Event Scheduling
System Simulation and Modelling with types and Event SchedulingBootNeck1
 
Indian Dairy Industry Present Status and.ppt
Indian Dairy Industry Present Status and.pptIndian Dairy Industry Present Status and.ppt
Indian Dairy Industry Present Status and.pptMadan Karki
 
Mine Environment II Lab_MI10448MI__________.pptx
Mine Environment II Lab_MI10448MI__________.pptxMine Environment II Lab_MI10448MI__________.pptx
Mine Environment II Lab_MI10448MI__________.pptxRomil Mishra
 
US Department of Education FAFSA Week of Action
US Department of Education FAFSA Week of ActionUS Department of Education FAFSA Week of Action
US Department of Education FAFSA Week of ActionMebane Rash
 
An experimental study in using natural admixture as an alternative for chemic...
An experimental study in using natural admixture as an alternative for chemic...An experimental study in using natural admixture as an alternative for chemic...
An experimental study in using natural admixture as an alternative for chemic...Chandu841456
 
Arduino_CSE ece ppt for working and principal of arduino.ppt
Arduino_CSE ece ppt for working and principal of arduino.pptArduino_CSE ece ppt for working and principal of arduino.ppt
Arduino_CSE ece ppt for working and principal of arduino.pptSAURABHKUMAR892774
 
Why does (not) Kafka need fsync: Eliminating tail latency spikes caused by fsync
Why does (not) Kafka need fsync: Eliminating tail latency spikes caused by fsyncWhy does (not) Kafka need fsync: Eliminating tail latency spikes caused by fsync
Why does (not) Kafka need fsync: Eliminating tail latency spikes caused by fsyncssuser2ae721
 
Industrial Safety Unit-I SAFETY TERMINOLOGIES
Industrial Safety Unit-I SAFETY TERMINOLOGIESIndustrial Safety Unit-I SAFETY TERMINOLOGIES
Industrial Safety Unit-I SAFETY TERMINOLOGIESNarmatha D
 
Industrial Safety Unit-IV workplace health and safety.ppt
Industrial Safety Unit-IV workplace health and safety.pptIndustrial Safety Unit-IV workplace health and safety.ppt
Industrial Safety Unit-IV workplace health and safety.pptNarmatha D
 
CCS355 Neural Networks & Deep Learning Unit 1 PDF notes with Question bank .pdf
CCS355 Neural Networks & Deep Learning Unit 1 PDF notes with Question bank .pdfCCS355 Neural Networks & Deep Learning Unit 1 PDF notes with Question bank .pdf
CCS355 Neural Networks & Deep Learning Unit 1 PDF notes with Question bank .pdfAsst.prof M.Gokilavani
 
Correctly Loading Incremental Data at Scale
Correctly Loading Incremental Data at ScaleCorrectly Loading Incremental Data at Scale
Correctly Loading Incremental Data at ScaleAlluxio, Inc.
 
Call Girls Narol 7397865700 Independent Call Girls
Call Girls Narol 7397865700 Independent Call GirlsCall Girls Narol 7397865700 Independent Call Girls
Call Girls Narol 7397865700 Independent Call Girlsssuser7cb4ff
 
IVE Industry Focused Event - Defence Sector 2024
IVE Industry Focused Event - Defence Sector 2024IVE Industry Focused Event - Defence Sector 2024
IVE Industry Focused Event - Defence Sector 2024Mark Billinghurst
 
NO1 Certified Black Magic Specialist Expert Amil baba in Uae Dubai Abu Dhabi ...
NO1 Certified Black Magic Specialist Expert Amil baba in Uae Dubai Abu Dhabi ...NO1 Certified Black Magic Specialist Expert Amil baba in Uae Dubai Abu Dhabi ...
NO1 Certified Black Magic Specialist Expert Amil baba in Uae Dubai Abu Dhabi ...Amil Baba Dawood bangali
 
Solving The Right Triangles PowerPoint 2.ppt
Solving The Right Triangles PowerPoint 2.pptSolving The Right Triangles PowerPoint 2.ppt
Solving The Right Triangles PowerPoint 2.pptJasonTagapanGulla
 
Class 1 | NFPA 72 | Overview Fire Alarm System
Class 1 | NFPA 72 | Overview Fire Alarm SystemClass 1 | NFPA 72 | Overview Fire Alarm System
Class 1 | NFPA 72 | Overview Fire Alarm Systemirfanmechengr
 
Introduction-To-Agricultural-Surveillance-Rover.pptx
Introduction-To-Agricultural-Surveillance-Rover.pptxIntroduction-To-Agricultural-Surveillance-Rover.pptx
Introduction-To-Agricultural-Surveillance-Rover.pptxk795866
 
Sachpazis Costas: Geotechnical Engineering: A student's Perspective Introduction
Sachpazis Costas: Geotechnical Engineering: A student's Perspective IntroductionSachpazis Costas: Geotechnical Engineering: A student's Perspective Introduction
Sachpazis Costas: Geotechnical Engineering: A student's Perspective IntroductionDr.Costas Sachpazis
 

Recently uploaded (20)

System Simulation and Modelling with types and Event Scheduling
System Simulation and Modelling with types and Event SchedulingSystem Simulation and Modelling with types and Event Scheduling
System Simulation and Modelling with types and Event Scheduling
 
Indian Dairy Industry Present Status and.ppt
Indian Dairy Industry Present Status and.pptIndian Dairy Industry Present Status and.ppt
Indian Dairy Industry Present Status and.ppt
 
Mine Environment II Lab_MI10448MI__________.pptx
Mine Environment II Lab_MI10448MI__________.pptxMine Environment II Lab_MI10448MI__________.pptx
Mine Environment II Lab_MI10448MI__________.pptx
 
POWER SYSTEMS-1 Complete notes examples
POWER SYSTEMS-1 Complete notes  examplesPOWER SYSTEMS-1 Complete notes  examples
POWER SYSTEMS-1 Complete notes examples
 
young call girls in Rajiv Chowk🔝 9953056974 🔝 Delhi escort Service
young call girls in Rajiv Chowk🔝 9953056974 🔝 Delhi escort Serviceyoung call girls in Rajiv Chowk🔝 9953056974 🔝 Delhi escort Service
young call girls in Rajiv Chowk🔝 9953056974 🔝 Delhi escort Service
 
US Department of Education FAFSA Week of Action
US Department of Education FAFSA Week of ActionUS Department of Education FAFSA Week of Action
US Department of Education FAFSA Week of Action
 
An experimental study in using natural admixture as an alternative for chemic...
An experimental study in using natural admixture as an alternative for chemic...An experimental study in using natural admixture as an alternative for chemic...
An experimental study in using natural admixture as an alternative for chemic...
 
Arduino_CSE ece ppt for working and principal of arduino.ppt
Arduino_CSE ece ppt for working and principal of arduino.pptArduino_CSE ece ppt for working and principal of arduino.ppt
Arduino_CSE ece ppt for working and principal of arduino.ppt
 
Why does (not) Kafka need fsync: Eliminating tail latency spikes caused by fsync
Why does (not) Kafka need fsync: Eliminating tail latency spikes caused by fsyncWhy does (not) Kafka need fsync: Eliminating tail latency spikes caused by fsync
Why does (not) Kafka need fsync: Eliminating tail latency spikes caused by fsync
 
Industrial Safety Unit-I SAFETY TERMINOLOGIES
Industrial Safety Unit-I SAFETY TERMINOLOGIESIndustrial Safety Unit-I SAFETY TERMINOLOGIES
Industrial Safety Unit-I SAFETY TERMINOLOGIES
 
Industrial Safety Unit-IV workplace health and safety.ppt
Industrial Safety Unit-IV workplace health and safety.pptIndustrial Safety Unit-IV workplace health and safety.ppt
Industrial Safety Unit-IV workplace health and safety.ppt
 
CCS355 Neural Networks & Deep Learning Unit 1 PDF notes with Question bank .pdf
CCS355 Neural Networks & Deep Learning Unit 1 PDF notes with Question bank .pdfCCS355 Neural Networks & Deep Learning Unit 1 PDF notes with Question bank .pdf
CCS355 Neural Networks & Deep Learning Unit 1 PDF notes with Question bank .pdf
 
Correctly Loading Incremental Data at Scale
Correctly Loading Incremental Data at ScaleCorrectly Loading Incremental Data at Scale
Correctly Loading Incremental Data at Scale
 
Call Girls Narol 7397865700 Independent Call Girls
Call Girls Narol 7397865700 Independent Call GirlsCall Girls Narol 7397865700 Independent Call Girls
Call Girls Narol 7397865700 Independent Call Girls
 
IVE Industry Focused Event - Defence Sector 2024
IVE Industry Focused Event - Defence Sector 2024IVE Industry Focused Event - Defence Sector 2024
IVE Industry Focused Event - Defence Sector 2024
 
NO1 Certified Black Magic Specialist Expert Amil baba in Uae Dubai Abu Dhabi ...
NO1 Certified Black Magic Specialist Expert Amil baba in Uae Dubai Abu Dhabi ...NO1 Certified Black Magic Specialist Expert Amil baba in Uae Dubai Abu Dhabi ...
NO1 Certified Black Magic Specialist Expert Amil baba in Uae Dubai Abu Dhabi ...
 
Solving The Right Triangles PowerPoint 2.ppt
Solving The Right Triangles PowerPoint 2.pptSolving The Right Triangles PowerPoint 2.ppt
Solving The Right Triangles PowerPoint 2.ppt
 
Class 1 | NFPA 72 | Overview Fire Alarm System
Class 1 | NFPA 72 | Overview Fire Alarm SystemClass 1 | NFPA 72 | Overview Fire Alarm System
Class 1 | NFPA 72 | Overview Fire Alarm System
 
Introduction-To-Agricultural-Surveillance-Rover.pptx
Introduction-To-Agricultural-Surveillance-Rover.pptxIntroduction-To-Agricultural-Surveillance-Rover.pptx
Introduction-To-Agricultural-Surveillance-Rover.pptx
 
Sachpazis Costas: Geotechnical Engineering: A student's Perspective Introduction
Sachpazis Costas: Geotechnical Engineering: A student's Perspective IntroductionSachpazis Costas: Geotechnical Engineering: A student's Perspective Introduction
Sachpazis Costas: Geotechnical Engineering: A student's Perspective Introduction
 

Evaporation process

  • 1.
  • 3. CONTENTS; • Evaporation process • Objectives of evaporation • Evaporation equipment (Evaporator) • Parts of evaporator • Problems occurring in evaporator • Types of evaporator • Potential hazards • Environmental applications of evaporator
  • 4.
  • 5.
  • 6. OBJECTIVE OF EVAPORATION: • The objective of evaporation is to concentrate a solution consisting of a non volatile Solute and a volatile solvent. 1. Evaporation is conducted by vaporising a portion of the solvent to produce concentrated solution of thick liquor. 2. In evaporation the thick liquor is the valuable product and the vapours are condensed and discarded.
  • 7. EVAPORATION DIFFERS FROM OTHER OPERATIONS 1. Evaporation VS 1. Drying 2. Distillation 3. Crystallization 4. Water distillation ( large scale evaporation)
  • 8. EVAPORATOR; • An evaporator is a device used in a process to turn the liquid form of a chemical substance such as water into its gaseous- form/vapor.
  • 9. COMPONENTS OF AN EVAPORATOR: 1. Thermoexpansion Valve (TEV):Meters refrigerant flow and converts hot high pressure liquid to a cold low-pressure liquid. 2. Differential Pressure Switch: Monitors the cleanliness of the air filter 3. Evaporator Coil: Absorbs heat through the vaporization of low-pressure liquid. 4. Low-Pressure Cut Out Switch: Shuts off compressor when pressure drops from 27.3 psi. 5. EMI Filter and EMI Gasket: Dissipates and prevents EMI from affecting the operation of other electronic equipment located within close proximity. 6. Handle: Allows two people to lift evaporator assembly. 7. Terminal Board, Single Row: Allows for ease of troubleshooting and repair. 8. Condensate Drain Pan: Collects condensation from coil and discharges through drain hole. 9. Evaporator Fan Motor: Drives evaporator housing fan. 10.Evaporator Fan Housing: Draws air across evaporator coil to increase
  • 10. PROBLEMS The practical solution of evaporation problems is profoundly effected by character of the liquor is to be concentrated. It is the wide variation in liquor characteristics which demands experience and judgement in designing and evaporator . Some of the most important properties of the evaporatong liquid are as follows. 1. Concentration: On evaporation the concentration of solution increases. The density and viscosity increases with solid content until the liquor becomes more viscous for adequate heat transfer. Continued boiling of saturated solution causes crystals to form; these must be removed or the tubes clog. 2. Foaming: Some materials specially inorganic substances foam during evaporation. A stable foam accompanies the vapour out of the evaporator, causing heavy entertainment. In extreme cases the entire mass of the liquid may boil into vapour outlet and be lost.
  • 11. CONTINUE... 3. Temperature Sensitivity: Many fine chemicals, Pharmaceutical products, foods are damaged when heated to moderate temperatures for relatively short times. In concentrating such materials special techniques are needed to reduce both the temperature of liquid and the time of heating. 4. Scale: Some solutions deposit scale on the heating surface. The overall coefficient then diminishes until the evaporator may shut down and the tubes cleaned. When the scale is hard and insoluble, the cleaning is difficult and expensive. 5. Materials of construction: Whenever possible, evaporators are made of some kind of steel.Many solutions, however, attack ferrous metals or contaminated by them. Special materials such as copper, nickel, stainless steel, aluminium, impervious graphite and lead are then used. Since these materials are expensive, high heat transfer rates becomes specially desirable to minimize the first cost of the equipment.
  • 12. TYPES OF EVAPORATORS USED TODAY The chief types of steam heated tubler evaporator in use today are; 1. Shell and tube type • Long-tube vertical evaporator a. Upward flow (Rising film evaporator) b. Downward flow (Falling film evaporator) c. Forced circulation 2. plate type • Agitated-film evaporator
  • 13. ALSO • Flash evaporation • Vacuum evaporation • Centrifugal evaporator • Rotary evaporator • Vapor-compression evaporator • Evaporative cooler • Pumpable ice technology • Circulation evaporator
  • 14. A. UPWARD FLOW (RISING FILM EVAPORATOR): • The liquid being evaporated is feed from the bottom into long tubes and heated with steam condensing on the outside of the tube from the shell side. This is to produce steam and vapour within the tube bringing the liquid inside to a boil. The vapour produced then presses the liquid against the walls of the tubes and causes the ascending force of this liquid. As more vapour is formed, the centre of the tube will have a higher velocity which forces the remaining liquid against the tube wall forming a thin film which moves upwards. This phenomenon of the rising film gives the evaporator its name.
  • 15. B. DOWNWARD FLOW (FALLING FILM EVAPORATOR): • In falling film evaporators, the liquid product usually enters the evaporator at the head of the evaporator. In the head, the product is evenly distributed into the heating tubes. The liquid enters the heating tube and forms a thin film on the tube wall where it flows downwards at boiling temperature and is partially evaporated. In most cases, steam is used for heating the evaporator. The product and the vapor both flow downwards in a parallel flow. This gravity-induced downward movement is increasingly augmented by the co-current vapor flow. The separation of the concentrated product from its vapor takes place in the lower part of the heat exchanger
  • 16. C. FORCED CIRCULATION • Developed for processing fluids which are fouling, scaling, and crystallizing, The raw material liquid is circulated through circulation pump in the heating chamber and separation chamber at a high speed and heated up in the heating chamber while flashed in the separation chamber, to achieve efficient vapour-liquid separation. • The high flow speed of material liquid in the heat exchange tube can improve heat transfer efficiency. Evaporation process takes place in the separator instead of the heater. Therefore, the scaling caused by crystallization and precipitation in the
  • 17. AGITATED-FILM EVAPORATOR • The feed enters evaporator at top, tangential to shell and gets distributed along the shell by the distributor. The rotor blades spread the feed evenly on the heated surface into a thin film and further agitate the film. • Heating medium passing through the jacket evaporates the volatile component in feed. The vapor generated flow counter currently to feed and gets cleared in entrainment separator before leaving through vapor nozzle. The concentrate product comes out at bottom.
  • 18. PERFORMANCE OF EVAPORATOR The principal measures of performance of a steam- heated tubler evaporator are the capacity and the economy of the evaporator. • Capacity is defined as number of kilograms of water vaporized per hour. • Economy is defined as number of kilograms of water vaporized per kilogram of stream feed to the unit. • Steam consumptionis defined as the ratio of capacity of evaporator to the economy of evaporator (kilograms of steam per hour).
  • 20. ENVIRONMENTAL APPLICATIONS OF EVAPORATOR 1. Brine 2. Wastewater treatment 3. Manure 4. Sludge 5. By-product from bioethanol production 6. Food and agricultural waste 7. Fruit concentrate 8. Cement industries 9. Etc.