An evaporator operating at 50 kPa is used to concentrate juice from a solids content of 5% to a solids content of 25% using steam at 120 kPa (which leaves as condensate at 80°C). The initial temperature and flow rate of the feed juice are 15 °C and 5 kg/s. The overall heat transfer coefficient is 3500 W/m²-K and the area available for heat transfer is 25 m2. The feed juice has a boiling point rise of 12 °C and the specific heats of the feed, concentrated product and water are 3500 J/kg-K, 4000 J/kg-K and 4180 J/kg-K respectively. Calculate: a) The steam economy for the evaporator and, b) Heat transfer area.

Introduction to Chemical Engineering Thermodynamics
8th Edition
ISBN:9781259696527
Author:J.M. Smith Termodinamica en ingenieria quimica, Hendrick C Van Ness, Michael Abbott, Mark Swihart
Publisher:J.M. Smith Termodinamica en ingenieria quimica, Hendrick C Van Ness, Michael Abbott, Mark Swihart
Chapter1: Introduction
Section: Chapter Questions
Problem 1.1P
icon
Related questions
Question
An evaporator operating at 50 kPa is used to concentrate juice from a solids content of 5% to a solids
content of 25% using steam at 120 kPa (which leaves as condensate at 80°C). The initial temperature and
flow rate of the feed juice are 15 °C and 5 kg/s. The overall heat transfer coefficient is 3500 W/m²-K and
the area available for heat transfer is 25 m2. The feed juice has a boiling point rise of 12 °C and the specific
heats of the feed, concentrated product and water are 3500 J/kg-K, 4000 J/kg-K and 4180 J/kg-K
respectively. Calculate:
a) The steam economy for the evaporator and,
b) Heat transfer area.
Transcribed Image Text:An evaporator operating at 50 kPa is used to concentrate juice from a solids content of 5% to a solids content of 25% using steam at 120 kPa (which leaves as condensate at 80°C). The initial temperature and flow rate of the feed juice are 15 °C and 5 kg/s. The overall heat transfer coefficient is 3500 W/m²-K and the area available for heat transfer is 25 m2. The feed juice has a boiling point rise of 12 °C and the specific heats of the feed, concentrated product and water are 3500 J/kg-K, 4000 J/kg-K and 4180 J/kg-K respectively. Calculate: a) The steam economy for the evaporator and, b) Heat transfer area.
Expert Solution
Step 1

Evaporation is unit operation. The unit operation equipment is an evaporator that comes under heat transfer equipment. The amount of water is removed from the mixture by this there will be an increase in the concentration of the compound.  the steam economy is obtained from the amount of water vaporized to the steam used. The heat transfer area is obtained from log mean temperature, heat, and overall heat transfer coefficient. 

steps

Step by step

Solved in 2 steps

Blurred answer
Similar questions
Recommended textbooks for you
Introduction to Chemical Engineering Thermodynami…
Introduction to Chemical Engineering Thermodynami…
Chemical Engineering
ISBN:
9781259696527
Author:
J.M. Smith Termodinamica en ingenieria quimica, Hendrick C Van Ness, Michael Abbott, Mark Swihart
Publisher:
McGraw-Hill Education
Elementary Principles of Chemical Processes, Bind…
Elementary Principles of Chemical Processes, Bind…
Chemical Engineering
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY
Elements of Chemical Reaction Engineering (5th Ed…
Elements of Chemical Reaction Engineering (5th Ed…
Chemical Engineering
ISBN:
9780133887518
Author:
H. Scott Fogler
Publisher:
Prentice Hall
Process Dynamics and Control, 4e
Process Dynamics and Control, 4e
Chemical Engineering
ISBN:
9781119285915
Author:
Seborg
Publisher:
WILEY
Industrial Plastics: Theory and Applications
Industrial Plastics: Theory and Applications
Chemical Engineering
ISBN:
9781285061238
Author:
Lokensgard, Erik
Publisher:
Delmar Cengage Learning
Unit Operations of Chemical Engineering
Unit Operations of Chemical Engineering
Chemical Engineering
ISBN:
9780072848236
Author:
Warren McCabe, Julian C. Smith, Peter Harriott
Publisher:
McGraw-Hill Companies, The