July 12/13 2005

Flash-drying: a suitabletechnology for bulksolids processing

Ricard Fenollosa– Sales Manager Riera Nadeu S.A

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HOTorNOT Seminar

SOME BASIC CONCEPTS

Thermal separation: to form homogeneous groups of substanceswhichever mixed with other ones, applying heating energy.

Mix: Combination of 2 or more substances where all ingredientsare keeping its own physical identity. In a mix substances con be combined in any proportion. The properties of the mix are thecombined properties of all ingredients and these component can be recovered with no alteration from de mix without a chemicalreaction.

Drying operation is a contact mass transference (solid/liquid), where moisture mix will be transferred by means evaporation to thegaseous phase, based to the vapour pressure coming from the mixand the partial vapour pressure of the gas flow.

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More CONCEPTS

Vaporization: Runing of molecules from liquid phase to gas.

The molecules which run off are the more close to the hot surface.

So, evaporation is fastest; at same pressure level, when thetemperature is higher, due a large fraction of molecules haveenough energy to run off.

Effect of pressure:

3

4

17910,0991,0

1586,0860,6

1202,0600,2

1708,0930,8

1434,0750,4

°C bar °C bar

Temp.PresiónTemp.Presión

Boiling temeperatures of H2O at different

pressures:

CONCEPT

Heat transfer: process where there is energy interchangeamong several parts or among different element of onebody whose are at same temperature.

The heat is transferred by means convection, radiationor conduction. These three processes can be carried out simultaneously, but it can occur that one of themechanisms will be predominant on the other ones.

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When is used a thermal solid-liquid separation process?

When the specs. for separation of final products are no possible toreach by means mechanical methods: centrifugation, decanting, filtration, …

When product value permits it.

Potential Secondary Effects of Drying

Tension and shrinkage (constriction) of dried material) (i.e. ceramicmaterials)

Chemical changes (pirolisis, oxidations, ….)

Bio-chemical changes (food, proteins, …)

Estrcuctural changes (modification on crystalline phase, shape, particlesize,…)

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Solid – liquid relation

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Surface moisture Interstice moisture Solvation moisture

- Easy drying Difficult drying +

POWER NEEDED BY A DRYER:

Q (total)= Q sólid + Q líquid + Q evaporation + Q others

Qsólido = ms · Ces · ∆T

Qlíquido = ml · (Cel · ∆T + Cev · ∆T’)

Qevap = ml · ∆Hvap

Qotros if there are dispersion fluid, agitation, no isolationlooses,heating of drying from outside, ….

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TYPE OF DRYERS

FLUID BED

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TYPE OF DRYERS

FLUID BED

• Batch and continuous

• Product cooling if needed.

• Only drying of wet solids

• OK for eliminate interstice and

solvation moisture.

• Low thermal efficiency.

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TYPE OF DRYERS

PADDLE DRYER

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TYPE OF DRYERS

PADDLE DRYER

• Batch and continuous.

• Only Drying of wet solids

• Lumps formation during drying (not desired)

• Low thermal efficiency.

• No possible drying of solutions/ supensions

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TYPE OF DRYERS

BICONE DRYER

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TYPE OF DRYERS

BICONE DRYER

• Batch

• Wet solids drying only.

• Low drying temperatures

• Vacuum application

• Lumps formation during drying (not desired)

• Sterilization permitted

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TYPE OF DRYER

CONE DRYER

• Batch

• Wet solids drying only.

• Low drying temeperatures

• Vacuum application

• Lumps formation during

drying (not desired)

• Sterilization permitted

• Possibility of particle

coating

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TYPE OF DRYERS

SPRAY-DRYER

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TIPOS DE SECADORES

SPRAY-DRYER

• Continuous drying

• Pump able solutions/suspensions could be dried

• High temperatures for drying possible

• Large surface and volume for drying

• Possible to obtain granules, powder.

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TIPOS DE SECADORES

SECADOR DE BANDEJAS

• Trabajo por batch

• Secado de sólidos húmedos

• Inversión económica

• Posibilidad de utilización

de vacío

• Secado no homogéneo

• Precisa molturación /

disgregación posterior

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TYPES OF DRYERS

TURBULENCE DRYING

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• Continuous drying

• Wearing effect

• Wet solids drying

• Obtaining fine powder

• High temperatures for drying

• Milling effect as complementary

TYPES OD DRYERS

LIOFILIZERS

• Batch operation.

• High operation cost

• Drying temperature very low.

• Freeze drying

• Sterile conditions

• Evaporation capacity quite limited.

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TIPOS DE SECADORES

FLASH-DRYER

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TYPES OF DRYERS

FLASH-DRYER

+ Continuous process

• Wet solids and solutions and sus

pensions able to be dried.

• Short residence time

• Nice for thermosensible products

• Possibility of sieving pneumatically

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• Fine powder obtention

• Deagglomeration of initial lumps

• Large surface of drying.

• Low operation cost

• Possibility of sterilization w/ steam

RINA - JET DRYER (TOROIDAL TYPE – HIGH TURBULENCE)

RINA - JET DRYER (P & I DIAGRAM – Flow sheet)

RINA - JET DRYER (P & I DIAGRAM – Flow sheet)

RINA-JET type S1008 unit

RINA-JET S3632 type evap 7/8 tn/h

RINA-JET (Straight type - low turbulence)

RINA-JET type S1008 R unit

RINA-JET Slurry/suspension feeding nozzle

RINA-JET Slurry feeding system

RINA-JET Operation cost calculation

RINA-JET Operation cost calculation

RINA-JET Internal heating recuperation

RINA-JET External heating recuperation

RINA-JET Heating recuperation. Loweroperation cost and low CO2 emission

RINA-JET Special performances

RINA-JET Complete Centrifugation+Drying+JetMilling set

RINA-JET ZrO-AA lining.

Wearing protection.

TABLE WITH PARAMETERS COMPARISON OF DRYERS

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SíBatch0.1-10ppm5-90 %LowLiofilizer

NoContinuo10-5.0000.1-1 %5-80 %HighTurbulence dryer

NoContinuo10-10.0000.1-1 %5-98 %HighFlash dryer

SíBatch10-1000.1-2 %10-70 %LowTray dryer

NoContinuo10-10.0000.1-5 %20-98 %HighSpray dryer

SíBatch10-100ppm5-50 %LowCone

SíBatch10-100ppm5-50 %LowBicone

Sí / NoBatch/

Continuo10-50000.1-5 %5-50 %MedPaddle dryer

Sí / No

Vacuum

necessary

5-1.000

Evap.

capacity

5-50 %

Initial

moisture

Batch/

Continuo0.1-5 %MedFluid Bed

Type of

process

Final

moisture

Thermal

power

CHOICE AND SIZING OF A DRYING SYSTEM

Physical properties of materials to be dried and dried product :

Presentation (wet solid, slurry, solution)

Viscosity,

Particle size distribution

Thermal conductivity,

Latent heat of liquid to evaporate,

Wearing (abrasion effect)

Porosity,

Fusion point - melting -,

Etc.

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CHOICE AND SIZING OF A DRYING SYSTEM

Chemical properties of dry solid and liquid:

Odour,

Thermal stability,

Flammability,

Reactivity in front drying gases,

Corrosion effect,

Existence of several crystalline phases,

Proportion solid – liquid

Etc.

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CHOICE AND SIZING OF A DRYING SYSTEM

Properties of flow of material to be dried:

Quantity of product to be dried per time unit,

Quantity od liquid to be separated,

Continuous or discontinuous process,

Material handling

Etc.

Drying kinetics

Lugar de instalación

Size of building or area to be sited.

ATEX area

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CHOICE AND SIZING OF A DRYING SYSTEM

Environmental conditions:

Noise restrictions,

Dangerous emission vapours of liquid to atmosphere.

Dangerous leakages of dried product by exhaust.

Etc.

Tech specs for dried product:

Bulk density,

Particle size distribution,

Crystalline structure,

Residual (final) moisture

Sterilization

Etc.

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CHOICE AND SIZING OF A DRYING SYSTEM

Economical considerations:

Value (added) of the product,

Operation cost (man power, energy costs, etc.)

Heat recovery possibilities,

Heat from exhausts to be used (cogeneration)

Etc.

Validation and certification:

Process validation FDA

GMP/GAMP

Certification CE-ATEX

HazOp studies

CIP Validation Riboflavin tests

SIP Validation

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SOME PRACTICAL APPLICATIONS

XXFumaric

Acid

XXIron oxide

XXXXBarium

Sulfate

X

X

X

Turb.

dryer

XXXXXXHerbicides

XXCalc.

carbonate

XXCeramic

enamels

XXXXXXAntibiótics

XXXXXXAminoacids

X

Spray

dryer

X

Flash

dryer

Tray d.

Waste water

ConeBiconePaddle

dryer

Fluid

bed

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SOME PRACTICAL APPLICATIONS

XXXXXXAPI’s

XXXXXPectine

XXXXXOxàlic àcid.

XrXSoda

bicarbonate

XXCopper

oxiclorure

XXXXXCopper

sulfate

XXXLactose

XXPlant extracts

X

Turb.

dryer

XXXPolimers

XXXKaolin

Spray

dryer

Flash

dryer

Tray d.ConeBiconePaddle

dryer

Fluid

bed

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SOME PRACTICAL APPLICATIONS

XXXOrg/Inorganic

pig,ments

XXXXXZinc Oxide

XXTartaric acid

XXrXStarch

XXXSulphur

XXXXTitanium

dioxixe

XXXXEstearates

X

Turb.

dryer

XXSilica gel

XMicro

celulose

Spray

dryer

Flash

dryer

Tray d.ConeBiconePaddle

dryer

Fuid

bed

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Some questions ...

… and t

hank yo

u for yo

ur atten

tion.