Presentation Mse 260

8/14/2019 Presentation Mse 260

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SPRAY DRYINGSPRAY DRYING,,

GEL CASTINGGEL CASTING,,HOT ISOSTATIC PRESSINGHOT ISOSTATIC PRESSING

; AND; ANDPOWDER INJECTION MOLDPOWDER INJECTION MOLD

RYAN D. CORPUZRYAN D. CORPUZ


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SPRAY DRYINGSPRAY DRYING

a very widely applied, technical method used to

dry aqueous or organic solutions, emulsions

etc., in industrial chemistry and food industry

the transformation of feed from a fluid state intoa dried particulate form by spraying the feed into

a hot drying medium

The mixture being sprayed can be a solvent, em


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The complete process of spray dryingThe complete process of spray drying

basically consists of a sequence of fourbasically consists of a sequence of four

processesprocesses::

Dispersion of the feed solution in sma

Mixing of spray and drying medium (ai

Open-cycle and closed cycle system Drying of spray (removal of moisture)


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Dispersion of the feed solution inDispersion of the feed solution in

small dropletssmall droplets

dispersion can be achieved with a pressurenozzle, a two fluid nozzle, a rotary disk atomiseror an ultrasonic nozzle.

different kinds of energy can be used to dispersethe liquid body into fine particles

atomiser type depends upon the nature andamount of feed and the desired characteristics

of the dried product The higher the energy for the dispersion, the

smaller is the generated droplets.


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Mixing of spray and drying medium (air)Mixing of spray and drying medium (air)

with heat and mass transferwith heat and mass transfer

The manner in which spray contacts the

drying air has great bearing on dried

product properties by influencing droplet

behaviour during drying.

mixing defines the method of spray drying


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MIXING IS ACHIEVED BY ANY OFMIXING IS ACHIEVED BY ANY OF

THE FOLLOWING:THE FOLLOWING:

Co-Current flow

Counter-Current flow

Combined Disk atomizer (rotary wheel)


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Co-Current flowCo-Current flow

The material is sprayed in the same

direction as the flow of hot air through the

apparatus


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Counter-Current flowCounter-Current flow

The material is sprayed in the opposite

direction of the flow of hot air


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CombinedCombined

The advantages of both spraying methods

mentioned earlier are combined.


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Disk atomizer (rotary wheel)Disk atomizer (rotary wheel)

The material to be sprayed flows onto a

rapidly rotating atomizing disk and isconverted to a fine mist.

The drying air flows in the same direction

CLOSE AND OPEN


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Open-cycle and closed cycleOpen-cycle and closed cycle

systemsystem

open-cycle system, air stream is heated

electrically or in a burner and after the

process exhausted to atmosphere

closed cycle system, the heating medium

is recycled and reused


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Drying of spray (removal ofDrying of spray (removal of

moisture)moisture)

As soon as droplets of the spray come intocontact with the drying air, evaporationtakes place from the saturated vapour film

which is quickly established at the dropletsurface.

Due to the high specific surface area andthe existing temperature and moisturegradients, an intense heat and masstransfer results in an efficient drying.


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Diagram of the dry air flowDiagram of the dry air flow

TO APPLICATION


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Diagram of the product flow andDiagram of the product flow and

spray nozzlespray nozzle

TO THE 4 PROCESS OF DRYING


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OVERVIEW OF APPLICATIONSOVERVIEW OF APPLICATIONS


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GELCAST


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GEL CASTINGGEL CASTING

is a forming process similar to slip casting

for making complex-shaped parts

produces large complex-shaped parts that

are strong enough to be machined before

firing

this process is simple, economical, and

uses conventional equipment


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A P P L I C A T I O N SA P P L I C A T I O N S

large, complex-shaped components

large components having simple shapes

prototypes custom manufacturing

adding features to a cast part that would

be too difficult or too costly to include inthe mold


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HOT ISOSTATIC PRESSINGHOT ISOSTATIC PRESSING

subjects a component to elevated

temperatures and pressures to eliminate

internal microshrinkage

a slow process and takes 6-24 hours for

completion

for low production volumes of costly alloys

and advanced composites


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sintering kineticssintering kinetics

where p is the porosity at time t, po is the

initial porosity, and k is a temperature-dependent hot-pressing constant, determined

from the analysis of experimental data


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APPLICATIONSAPPLICATIONS

densifying castings

diffusion bonding of dissimilar materials

component repair powder metal consolidation


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Powder Metal MarketPowder Metal Market

HIP technology is applied in four separate

areas:

Consolidation of powder metals (PM)

Creation of PM shapes

Production of near-net shapes

Cladding


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PIM


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APPLICATIONSAPPLICATIONS

PIM is especially competitive in the

production of small intricately shapedcomponents

silicon carbide turbochargers

radial rotors for heat engines alumina thread guides

rare earth magnet pole pieces for hard

disk drives and stainless steel gear wheels for electric

tooth brushes


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TTHANK YOU!!!HANK YOU!!!

Presentation Mse 260

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