Spray drying is a process in which a liquid containing dissolved or suspended solids is injected into a chamber through a spray nozzle or centrifugal disk atomizer. The resulting mist is contacted with hot air, which evaporates most or all of the liquid, leaving the dried solids to fall to a conveyor belt at the bottom of the chamber. Milk (70% H,O) Wet air 311 m'/min 83°C, 1 atm Dried milk Inlet air 167°C,-40 cm H,0 Powdered milk is produced in a spray dryer 6 m in diameter by 6 m high. Air enters at 167 °C and -40 cm H2O. The milk fed to the atomizer contains 70% water by mass, all of which evaporates. The outlet gas contains 12 mole % water and leaves the chamber at 83 °C and 1 atm (absolute) at a rate of 311 m/min. (a) Calculate the production rate of dried milk and the volumetric flow rate of the inlet air. Estimate the upward velocity of air (m/s) at the bottom of the dryer.
Spray drying is a process in which a liquid containing dissolved or suspended solids is injected into a chamber through a spray nozzle or centrifugal disk atomizer. The resulting mist is contacted with hot air, which evaporates most or all of the liquid, leaving the dried solids to fall to a conveyor belt at the bottom of the chamber. Milk (70% H,O) Wet air 311 m'/min 83°C, 1 atm Dried milk Inlet air 167°C,-40 cm H,0 Powdered milk is produced in a spray dryer 6 m in diameter by 6 m high. Air enters at 167 °C and -40 cm H2O. The milk fed to the atomizer contains 70% water by mass, all of which evaporates. The outlet gas contains 12 mole % water and leaves the chamber at 83 °C and 1 atm (absolute) at a rate of 311 m/min. (a) Calculate the production rate of dried milk and the volumetric flow rate of the inlet air. Estimate the upward velocity of air (m/s) at the bottom of the dryer.
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
Related questions
Question
Transcribed Image Text:Q 3. Spray drying is a process in which a liquid containing dissolved or suspended solids is
injected into a chamber through a spray nozzle or centrifugal disk atomizer. The resulting
mist is contacted with hot air, which evaporates most or all of the liquid, leaving the dried
solids to fall to a conveyor belt at the bottom of the chamber.
Milk (70% H,O)
Wet air
311 m/min @ 83°C, 1 atm
Dried milk
Inlet air
167°C,-40 cm H,0
Powdered milk is produced in a spray dryer 6 m in diameter by 6 m high. Air enters at
167 °C and -40 cm H2O. The milk fed to the atomizer contains 70% water by mass, all of
which evaporates. The outlet gas contains 12 mole % water and leaves the chamber at 83
°C and 1 atm (absolute) at a rate of 311 m/min.
(a) Calculate the production rate of dried milk and the volumetric flow rate of the inlet
air. Estimate the upward velocity of air (m/s) at the bottom of the dryer.
39%
27°C
Transcribed Image Text:(b) Engineers often face the challenge of what to do to a process when demand for a
product increases (or decreases). Suppose in the present case production must be doubled.
(i) Why is it unlikely that the flow rates of feed and air can simply be increased to
achieve the new production rate? (ii) An obvious option is to buy another dryer like the
existing one and operate the two in parallel. Give two advantages and two disadvantages
of this option. (iii) Still another possibility is to buy a larger dryer to replace the original
unit. Give two advantages and two disadvantages of doing so. Estimate the approximate
dimensions of the larger unit.
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution!
Trending now
This is a popular solution!
Step by step
Solved in 7 steps with 1 images
Recommended textbooks for you
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…
Chemical Engineering
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY
Elements of Chemical Reaction Engineering (5th Ed…
Chemical Engineering
ISBN:
9780133887518
Author:
H. Scott Fogler
Publisher:
Prentice Hall
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…
Chemical Engineering
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY
Elements of Chemical Reaction Engineering (5th Ed…
Chemical Engineering
ISBN:
9780133887518
Author:
H. Scott Fogler
Publisher:
Prentice Hall
Industrial Plastics: Theory and Applications
Chemical Engineering
ISBN:
9781285061238
Author:
Lokensgard, Erik
Publisher:
Delmar Cengage Learning
Unit Operations of Chemical Engineering
Chemical Engineering
ISBN:
9780072848236
Author:
Warren McCabe, Julian C. Smith, Peter Harriott
Publisher:
McGraw-Hill Companies, The