Proceedings of
The First International Symposium on Drying

McGill University, Montreal, Canada,
August 3-5, 1978

A.S. MUJUMDAR
Editor

Published by SCIENCE PRESS, Princeton


CONTENTS

FOREWORD i
PREFACE ii
SECTION I.
DRYING THEORY AND MODELLING
A Short-Cut Method for the Calculation of Drying Rates in Case of a Concentration-dependent Diffusion Coefficient
W.J.A.H. Schoeber, Eindhoven University of Technology, Eindhoven, The Netherlands
1
The Kinetics of Drying Microporous Materials
J.M.D. MacElroy and J.J. Kelly, University College Dublin, Dublin, Ireland
10
A Transport Phenomena Analysis of Air Drying of Foodstuffs
E. Rotstein, PLAPIQUI (UNS-CONICET) Bahia Blanca, Argentina; and A.R.H. Cornish, Imperial College, London, England
24
Determination of the Diffusivity of Moisture Within Wet Materials
I. Shishido and S. Ohtani, Dept. of Chemical Eng., Tohoku University, Sendai, Japan
30
Adiabatic Drying of Hygroscopic Materials
K. Werling, Chemical Eng., University of Lund, Sweden
36
An Approximation of Transient Change of Moisture Distribution Within Porous Materials Being Dried
M. Suzuki and S. Maeda, Dept. of Chemical Eng., Tohoku University, Sendai, Japan
42
Numerical Evaluation of Transfer Coefficients of Drying Process of Porous Bodies in the Falling Rate Period
S. Endrenyi, Technical University Budapest; and D. Szentivanyi, Institute of Inland Trade for Organization, Budapest, Hungary
48
Drying Mechanism of a Non-Supported Droplet
R. Toei, M. Okazaki, and T. Furuta, Dept. of Chemical Eng., Kyoto University, Kyoto, Japan
53
Capillary Mechanism in Drying
B. Kisakurek, Middle East Technical University, Turkey; and O. Gebizlioglu, Princeton University, Princeton, New Jersey, U.S.A.
59
Drying Apparatus for Crystal Urea
T. Jojima and K. Iida, Mitsui Toatsu Chemicals Inc.; and M. Nobue, S. Nioh, Toyo Engineering Corp., Tokyo, Japan
66
On the Period of Constant Drying Rate
J. van Brakel and P.M. Heertjes, Delft University of Technology, Laboratory of Chemical Eng., Delft, The Netherlands
70
Role of Relative Transfer Factors in Controlling the Operation of Driers
L. Imre and I. Szab? Technical University, Budapest, Hungary
76
Spinning a Filament in Dry Spinning
Y. Sano, Dept. of Chemical Eng., Yamaguchi University, Tokiwadai, Ube, Japan
82
Calculation of Drying Parameters for the Penetrating Evaporation Front
S. Szentgyorgyi and K. Molnar, Dept. of Chemical Machinery and Agricultural Industries, Technical University, Budapest, Hungary
92
A Non-Equilibrium Thermodynamics Approach to Transport Phenomena in Capillary Porous Media
M. Fortes and M.R. Okos, Purdue University, W. Lafayette, U.S.A.
100
SECTION II.
DRYING OF GRANULAR MATERIALS
Convective Drying of Small Wood Particles
O.A. Plumb, P.C. Malte, R.W. Cox, and R.J. Robertus, Dept. of Mechanical Eng., Washington State University, Pullman, Washington, U.S.A.
110
Puffing and Drying of Grains
T. Akao and R. Aonuma, Kikkoman Shoyu Co. Ltd., Noda-shi, Japan
117
Conductive Heating Drying of Granular Bed With Low Water Content
M. Okazaki, T. Yamasaki, and R. Toei, Dept. of Chemical Eng., Kyoto University, Kyoto, Japan
122
The Inverse Region Criterion in the Design of Through-Circulation Dryers
L.J. Stradling, Jr. and J.R. Thygeson, Jr., Drexel University, Philadelphia, U.S.A.
130
Particle Residence Time Distribution in Plug Flow Fluid Bed Dryers
D. Reay, AERE Harwell, Oxfordshire, England
136
Continuous Removing Devices of Large Particles from Fluidized Bed Dryer
T. Takahashi, Kurimoto Iron Works, Osaka, Japan
145
A High Efficiency Thermal Drying System
Vere Maffet, Organic Recycling Inc., Pennsylvania, U.S.A.
147
Volumetric Heat Transfer Coefficient and Pressure Drop in Rotary Dryers and Coolers
H. Hirosue, National Industrial Research Institute of Kyushu Tosu; and H. Shinohara, Kyushu University, Fukuoka, Japan
152
Transport Processes in Packed Beds
M. Parti, Dept. of Chemical Machinery and Agricultural Industries, Technical University, Budapest, Hungary
160
SECTION III.
DRYING OF CONTINUOUS SHEETS
The Optimization of Textile Tenter Frame Dryer Operations
W.F. Beckwith, J.N. Beard, Jr. and R.L. Gross, Dept. of Chemical Eng Clemson University, Clemson, South Carolina, U.S.A.
168
Coupled Heat and Mass Transfer Under a Laminar Impinging Jet
Y.K. Li, A.S. Mujumdar, and W.J.M. Douglas, Dept. of Chemical Eng., McGill University, Montreal, Canada
175
Drying Rate and Energy Consumption for an Air Cap Dryer System
D.A. Rounds and G.L. Wedel, Beloit Corporation, Beloit, Wisconsin, U.S.A.
185
Evaluation of Drying Times, Drying Rates, and Evaporative Fluxes When Drying Wood With Impinging Jets
H.N. Rosen, North Central Forest Experiment Station, USDA Forest Service, Carbondale, Illinois, U.S.A.
192
Drying and Shrinkage of Paper
W.Z. Tarnawski, Institute of Papermaking and Paper Machines, University of Lodz, Lodz, Poland
201
The Analysis of the Drying Process in the Thin Films of Ink
H. Hardisty, University of Bath, Bath, U.K.
208
SECTION IV.
GENERAL TOPICS
Opinions About Selection and Design of Dryers
J. van Brakel, Delft University of Technology, Laboratory of Chemical Technology, Delft, The Netherlands
216
Drying of Solution Droplets in Superheated Vapors
C.G. Moyers, Jr., Union Carbide Corporation, S. Charleston, West Virginia, U.S.A.
224
The Effect of Energy Costs, Safety and Environmental Factors on Dryer Design
R.W. Lang, Stork-Bowen Ltd., London, England
230
Effect of Drying Temperature and Cooling Rate on the Physical Properties of Shelled Corn. A New Measuring Method
G. Sitkei, Agricultural Machinery Trust, Budaors, Hungary
236
Drying of Gels
D. Gehrmann and W. Kast, Technische Hochschule, Darmstadt, W. Germany
239
Spray Drying Problems for High Viscous and Heat Sensitive Food
H. Hayashi, T. Wada and E. Kumazawa, Snow Brand Milk Products Co. Ltd., Higashi-ku Sapporo, Japan
247

SUBJECT INDEX
254

AUTHOR INDEX
254