Post on 18-Dec-2021
Recent Innovations in Sustainable Drying Technologies
Prof Arun S Mujumdar
McGill University, Montreal, Canada
University of Queensland, Brisbane, Australia
NIFTEM, Kundli, India
KMUTT, Bangkok, Thailand
www.arunmujumdar.com September 2017
Sustainable Drying Technologies - Role of Global R&D
可持续干燥技术 - 在全球研发中的作用
Professor Arun S Mujumdar McGill University, Montreal & Western University, London, Canada
加拿大 麦吉尔大学 和 西安大略大学 Honorary Professor, Jiangnan University, China
荣誉教授,中国 江南大学 Plenary Lecture, ADC2017, Wuxi, China
September 2017
www.arunmujumdar.com
Introduction – Role of ADC/IDS/LDRT – Vison/Mission
Innovation – Needs and challenges Selected innovations
o SHSD (Superheated Steam Drying) o Pulse Combustion Drying o DIC/Swell Drying o Flame Drying o Miscellaneous
Closing remarks
To provide a global forum for exchange, transfer of ideas, knowledge on drying
To encourage industry-academia transfer of knowledge, knowhow and technology
Develop a truly inter- and cross-disciplinary forum across geopolitical and industrial sectorial boundaries
Establish a new research discipline of Drying R&D combining transport phenomena with material science
To promote innovation essential to have a central location to disseminate knowledge, exchange ideas and network globally
Short answer: Qualified, yes With over 4000 papers from 80+ countries over four decades
IDS has contributed to the technical literature in drying. IDS spawned many other similar fora e.g. ADC, AIDC, WFCFD
and stimulated others like NDC, CDC, Nigerian DC. Let to the only archival peer-reviewed journal devoted to
drying and dewatering – Drying Technology – An International Journal
It is relevant to look into the history of the journal at this point.
Following statistical information available on ASM website: www.arunmujumdar.com
Montreal (3) Birmingham
Kyoto Boston Prague
Versailles
Gold Coast
Beijing
Noordwijkerhout Kraków
Thessaloniki Sao Paulo
Bali Penang
Bangkok (2)
Sao Paolo
Montreal
Veracruz
Kolkata Trondheim
Copenhagen Karlstad
Mumbai (11)
Budapest
Gifu
KL
IDS ADC NDC IADC IWSID/ WFCFD
Hyderabad
Iceland Tianjin
Hong Kong
Xiamen
Magdeburg
Lyon
Wuxi
A few authors made massive contribution of papers, reviews – Pereto principle – 20% contributed 80%
Over last decade situation has turned around but for quality assurance dedicated referees are the “key” to success – still a challenge due to heavy manuscript flow
Latest Impact Factor (2016) – 1.98
Latest 5 year Impact factor (2015) – 2.006
True impact in industrial application
No of papers since 2005 - ∼2318
No of authors per volume since 2005– ∼300
No of countries/territories contributing to LDRT (All years) – 105
Projected Impact Factor for 2016 – 2.0+
Source: ISI Web of Science (last accessed on Aug 1, 2017)
Year Impact factor
2016` 1.98
2015 1.85
2014 1.52
2013 1.74
2012 1.81
2011 2.08
2010 1.66
2009 1.05
2008 1.39
2007 1.17
2006 1.10
2005 1.03
Two-year impact factor of Drying Technology
Source: ISI Web of Science (last accessed on Aug 1, 2017)
Country No. of papers published
China 479
Canada 397
United States 316
France 281
Brazil 266
Australia 260
Poland 226
Japan 215
Singapore 171
Thailand 168
India 159
Germany 123
Turkey 112
Top contributing countries during 1982-Present (Only RESEARCH articles)
Source: ISI Web of Science (last accessed on Aug 1, 2017)
Author Name No. of papers published
Mujumdar, A.S. 222 Zhang, M. 83 Langrish, T.A.G. 60 Soponronnarit, S. 60 Chen, X.D. 54 Freire, J.T. 42 Raghavan, G.S.V. 41 Maroulis, Z.B. 40 Kudra, T. 37 Perre, P. 35 Prachayawarakorn, S. 34 Lee, D.J. 33 Zbicinski, I. 31
Top contributors during 1982-Present (Only RESEARCH articles)
Source: ISI Web of Science (last accessed on Aug 1, 2017)
Arun S Mujumdar (Editor-in-Chief)
Sakamon Devahastin
(Senior Associate Editor)
B. Adhikari; Takeshi Furuta; Tadeusz Kudra; Timothy A.G. Langrish and C.L. Law
(Associate Editors)
Sachin V Jangam; Agus P. Sasmito; Meng W. Woo; Zhonghua Wu and Azharul Karim, Hong Wei
(Assistant Editors)
22 EAB members from 16 countries 3000+ authors from 100+ countries 185 papers published in 2015
27 review papers published in 2012-2015
A Brief SWOT Analysis Strengths Globalized, multi-disciplinary, multi-industry
forum with huge opportunities for innovation Weaknesses Highly interdisciplinary; applied discipline;
Options/ Opportunities
Broad range of problems in drying/dewatering with over 10000 materials in several hundreds of dryers . Huge opportunities for enhancing efficiency, quality, environmental impact
Threats As applied discipline must benefit industry/society. Technology transfer is key. Must attract active industry participation. A real challenge. Threatens innovation.
S
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Introduction - What is innovation? Novelty, Renovation versus Innovation
Why Innovation? Incremental vs Radical
Technology Development via Industry-University Collaboration
Time scales of Innovation in Drying-Academia-Industry appear to be a mismatch
Innovative dryers-most are at lab and pilot scales-Need to develop reliable scale-up and LCA models
New product or process
Higher capacities than current technology permits
Better quality than currently feasible
Reduced overall cost
Reduced environmental impact, sustainable
Safer operation; more flexibility
Better efficiency
Quality trumps energy saving currently
Innovative dryers for particulates
Modified Fluid Beds
Impinging Streams
Vibrated
Modified spouted beds
Agitated Mechanically
Pulsed Air
Periodic localized Fluidization
Superheated Steam
Pulsed
2D
Superheated Steam
Mechanical fluidization
SB driven by pulse combustor
2D
Complex Geometries
Superheated steam
Vortex Type
Classification of Innovations
Based on way heat is supplied
Multi - staging
•Steady
•Periodic
•on/off
•Combination of different modes - concurrent or sequential
•Conventional or innovative dryers in multi-stage arrangement
Cyclic Operation
•Pulsed fluidization or spouting
• Steady thermal energy impact
• Constant gas flow
• Single mode of heat input
• Single dryer type – single stage
• Air/combustion gas as convective medium
Conventional Innovative
• Intermittent energy input
• Variable gas flow
• Combines different modes of heat input
• Multi-stage; each stage maybe different dryer type
• Superheated steam drying medium; flame drying
Developments in Drying A Coarse Classification
Developments in Drying Coarse Classification
Empirical (> 90% published work)
Modeling Drying
*Modeling Dryers
Lab Scale
Pilot Scale
** Industrial Scale
• Microscopic • Macroscopic • Analysis /
scale-up / Control
• Smart dryers
> 80% ~ 10% ~ 10%
* Dependent on dryer type and material
** Unpublished; difficult to guestimate
Industrial Drying - Innovations
Incremental Evolutionary
Radical / *Revolutionary
• Low risk • Hybrids of known
technologies • More accepted by
industries
• High risk • Not readily
accepted • High R&D cost
* Game changing technologies - few
Long half-life of drying technologies attracts less R&D. ROI on R&D investment not attractive in most sectors
Coarse Classification of Innovations in Thermal Dryers
How wet material is handled
Miscellaneous
• Stationary • Moving • Agitated • Vibrated • etc
• Convection • Conduction • Radiation • MW/RF • Combinations /
Concurrent / Consecutive
• Intermittent
How heat is supplied to dryer
• Hybrids • Multi-staging • In-situ heat
generation – Rema flam / Flame Drying
• Pulse Combustion Drying
• Superheated Steam Drying
Intensification Techniques for Fluidized Beds
Internal heat
exchangers
Vibration
Agitation
Microwave
field
Pulsation of
Flow
Rotating bed
Superheated steam
Some techniques used to enhance efficiency e.g. intermittent fluidization; low pressure fluidization, may decrease the drying
rate but contribute to improved product quality
Variable operating parameters: pulsating gas flow, variable temperature, adjustable heat input or periodic fluidization
energy and cost effectiveness Pulsating – provides vertical vibration, improving
the fluidization quality Bed temperature - batch FB - constant - adjustable
heat input Pulsating FB –rotated hot air inlet – intermittent
drying times
Pulsating Fluidized Bed
low energy consumption due to high specific moisture extraction rate (SMER)
high coefficient of performance (COP) wide range of drying temperature (-20 0C to 110 0C)
and humidity environmental friendly high product quality. suitable for heat sensitive products (food, bio-origin
products.
Fluid Bed Heat Pump Dryer
Homogeneous FB without channeling or bubbles; high gas velocity possible Deeper bed depth is possible if the bed is agitated-Not commonly used
• Centrifugal / rotating FB - flowing gas radially - rotating cylindrical perforated distributor.
• Promising, contacting Umf and Ut can be controlled
Variant Conventional Modified FBD
Mode of heat transfer
Only convection Convection + conduction (immersed heaters in bed) + radiative heat transfer (MW assisted fluid beds)
Gas flow Steady Pulsating; on/off
Mode of fluidization
Pneumatic Mechanically agitated / vibrations
Drying media Air / flue gases Superheated steam / heat pump assisted (even using inert media)
Type of material dried
Particulate material Drying of pastes / slurries using bed of inert particles
Developments in fluid bed drying (comparison Modified and conventional fluidized beds)
Some Recent Innovations*
Inclined Blade Paddle Dryer TSK, Japan
Pulse Combustion Dryer
• Sludge • Pastes
• Textile • Liquids
Remaflam / Flame Drying
• Liquids
DIC / Swell Drying
• Illustrative only, No commercial endorsement is intended or implied
• LCA, Sustainability not examined for most innovations yet
Enhancement of Drying Rates Vibration (e.g. Vibrated bed dryers) Pulsations (e.g. Impinging jets) Sonic or ultrasonic fields (e.g. pulse combustion
dryers) Dielectric fields {MW, RF} (e.g. MW-assisted steam
drying) Superheated steam drying Cost effectiveness not known for most cases
Vacuum steam dryers for wood*
Vacuum steam dryers for silk cocoons**
Fluidized bed dryers for coal*
Impingement and/or through dryer for textiles, paper***
Flash dryers for peat (25 bar)****
Conveyor dryers for beet pulp (5 bar)****
Fluidized bed dryers for pulps, sludges*
* Extensive commercial applications ** Laboratory scale testing *** Pilot scale testing ****At least one major installation
Superheated Steam Dryers
Near Atmospheric Pressure High Pressure Low Pressure
• Flash dryers with or without indirect heating of walls
• FBDs with or without immersed heat exchangers
• Spray dryers • Impinging jet dryers • Conveyor dryers • Rotary dryers • Impinging stream dryers
Fluid bed
Possible Types of SSD
Devahastin et al., Drying Technol., 22, 1845-1867 (2004)
Photographs of carrot cubes underwent LPSSD and vacuum drying
SEM photographs of carrot undergoing (a)LPSSD, (b) vacuum drying
SEM photographs showing pore distribution of carrot undergoing (a)LPSSD, (b) vacuum drying
Devahastin et al., Drying Technol., 22, 1845-1867 (2004)
• Pulse combustion is intermittent ; can be subsonic or supersonic Mach
Number >1.0 (supersonic) Features Steady Pulsed
Combustion intensity (kW/m3) 100-1000 10000-
50000 Efficiency of burning (%) 80-96 90-99
Temperature level ( K) 2000-2500
1500-2000
CO concentration in exhaust (%) 0-2 0-1
NOx concentration in exhaust (mg/m3) 100-7000 20-70
Convective heat transfer coefficient (W/m2k) 50-100 100-500
Time of reaction (s) 1-10 0.01-0.5 Excess air ratio 1.01-1.2 1.00-1.01
http://blastwavejet.com/pulsejet.htm
• High drying rates
– Increased turbulence and flow reversal in the drying zone promote
gas/materials mixing
– Decreased boundary layer thickness of materials
– Increased heat and mass transfer rates
– High driving force because of high gas temperature
• short contact time
– Suitable for some heat sensitive materials
• High energy efficiency and economic use of fuels
• Environmentally friendly operation
• Noise and scale-up issues
Dryers Typical evaporation capacity
Typical consumption (kJ/kgH2O)
PC dryers 250-2000 kg H2O/h 3000-3500
Tunnel dryer 5500-6000 Impingement
dryer 50 kg H2O/hm2 5000-7000
Rotary dryer 30-80 kg H2O/hm2 4600-9200
Fluid bed dryer 4000-6000
Flash dryer 5-100 kg H2O/hm3 4500-9000
Spray dryer 1-30 kg H2O/hm3 4500-11500 Drum dryer
(pastes) 6-20 kg H2O/hm2 3200-6500
• limited industrial data • Very promising technology
Product quality-pysical properties
Product color
PC spray drying Tradiational spray drying
White pale yellow
Product quality-pysical properties Product morphology
PC spray drying Tradiational spray drying
1. Hallow 2. Single 3. Soomth surface
1. Solid 2. Aggrigated 3. Coase surface
Apply step-wise change in operating conditions for batch drying
Especially final stage of drying – drying rates are sluggish (diffusion controlled) hence effect of external conditions is negligible
Use – stepwise change in operating conditions to save energy
Use – Combinations of modes of heat input Concept can be applied for different drying methods – tray
dryer, FBD, conveyor dryer etc. Flipping of product-expose wetter surface to drying agent
Classification of Intermittent Dryers
ON/OFF Type
Examples:
Pulsed fluidized beds
Pulsed heat pump drying
Cyclic
Examples:
Fixed/variable frequency
Multi-flash drying
Heat pump drying
Step-wise
Examples:
Convective drying of foods with step-wise change in operating conditions
Random Variations
Examples:
Use of hybrid heat inputs at random time as required
Some examples of Intermittent Drying
Rotating Jet Spouted Bed dryer
Pulsed bed - intermittent fluidization
Vibrated bed with tempering periods
Intermittent IR/MW in a batch heat pump dryer
Conveyor (Apron) dryer with parts of the dryer unheated
Aside from reduced energy/air consumption, product quality may be better for heat-sensitive and/or fragile solids. Slight increases in drying time are expected
MW Freeze drying • microwave can heat the material volumetrically; thus, greatly improving
freeze drying rate is possible • most promising techniques to accelerate drying and to enhance overall quality • Examples – Cabbage, marine products, banana chips, potato, skim milk
T
Cold trap
Vacuum Pump
MW freeze drying chamber
MW sourcefreeze drying chamber
• Flash + Fluid bed• Fluid bed + Packed bed • Vacuum + MW• Well-mixed fluid bed + plug flow fluid bed dryer
• Convection dryer + Vacuum frying
Some Hybrid Dryers
Liquid/ Paste Sheets (e.g. fruit leather)
Particulate, Granular products
• Spray + Fluid bed• Spouted bed or
fluid bed of inert particles
• Impingement + IRRadiation
• Fluid bed of inertparticles
Drying is highly energy intensive hence it adversely effects environment, plus good quality is needs to be maintained for foods – need for smart/intelligent dryers
Use mathematical models, advanced sensors and automatic control strategies to design smart dryer
A smart dryer: o Provides actionable information regarding the performance of the
drying system o Proactively monitors and detects errors or deficiencies in dryer
operation o Incorporates the tools, technologies, resources and practices to
contribute to energy conservation and environmental sustainability.
Designed to sense local drying conditions/product properties and adjust them in order to get specified quality at optimized energy consumption.
Industry-academia collaboration with tangible industry collaboration
Global networking – pool human and financial resources. Also promotes innovation and avoids duplication
Develop reliable math models to study innovative concepts before physical testing
Study carefully archival literature and conference papers for ideas and also collaborations
Crowd-sourcing to seek innovative ideas – often very successful
Despite low energy cost – R&D for innovation is needed
Quality, Carbon footprint are driving forces Better models for drying and dryers are still needed Industry collaboration is critical for technology
transfer LCA, sustainability analysis is recommended for all
innovations.
Books /monographs by Prof. Arun S. Mujumdar During 2009-2014
Visit us at: http://www.arunmujumdar.com/