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1)Suspension:

Heterogeneous Miture containing

solid particles that are su!!icientl"

large !or sedi#entation$%

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&articles:

Larger then 1 but less then 10 micron.Particles are visible under a microscope.Settle over time if left undisturbed.

Can be separated through a filter.Surface area exposed to fluid is constant.

&urpose:

Increase surface area, ate of dissolution.

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'#peller:

!xial"flo# impellers are used forsuspension.

$hree blade #ith s%uare pitch and four

blade #ith &'degree are common.

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'#peller Speed:

Sli# is carrie# up$ar# b% mil# stirring& ntt 'rm pile at bttm

(cal up$ar# )elcit% is greater thenterminal settling )elcit% ' particals*

ritical '#peller Speed:Critical +,ust-suspen#e# impeller spee# nc*

n particle remains lnger than 1 sec n the

)essel bttm*

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States o! Suspension:

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$o dissolve the solids

$o catal()e a chemical reaction

$o promote the gro#th of cr(stal from

a super saturated solution

'n he#ical &rocessing%%

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2)Dispersion:

Heterogeneous Miture in *hich

dispersed phase is uni!or#l" distri+utedin continuu# phase%$

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&articles:

Si)e of particle 0.01*' micron. Settle do#n if not disturbed but ver( little. !t high shear rate particles are bro+en,

diameter reduces and ne# surface are is

created. -ermentation Li%uid"li%uid/rops and gas"li%uidubbles

total interfacial area b# dispersed and

continuous material ma( var( according to

conditionand degree of Mixing.(Mean

diameter).

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'#peller:adial and axial flo# t(pe impellers.

$hat provide some of both shearturbulence and movement.

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)Blending:

Ho#ogeneous Miture o! t*o Misci+le

i.uids to !or# a single li.uid *ith no

/ariation in concentration !ro# point to

point$%

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i.uids:7niformit( at drop scale is re%uired.

$he li%uid is #ell mixed close to the impeller

/ue to the intense turbulence.

Large radial mixing but small mixing along the

flo#.

!t last li%uid returns to e(e of impeller foragain vigorous mixing.

889 mixing complete in ' circulations.

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'#peller:Small tan+"""Propeller,

:igh ;fficienc( Impeller

center mounted

Large tan+""""Side

;ntering Propeller or

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Static Mier:

:elical"element mixer

>ortex =ixer

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For lo* /iscosit":lending is done b( turbulence in #hich eddies

are formed #hich helps mixing

For high /iscosit":$he flo# is mostl( laminar

lending is done b( repeatedl( dragging a la(er

of one fluid through another.e.g.:and mixing of paint.

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'n he#ical &rocessing%%

In the manufacturing of perfume, blending is

re%uired to dilute the concentrated perfume oils

b( dissolving them in ethanol.Pharmaceutical, in?ection, s(ringeabilit(, pourse

level mixing.

2asoline re%uires uniformit( up to 1mm si)edrop variation in this causes @noc+ing.

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Char\product

Suspension Dispersion Blending

Purpose $urbidit( 7niformit( :omogeneit(

Si)e ofparticles

1 to 10 um 0.01*' um Less then0.01 um

Impellerused

!xial -lo# adial as #ellas !xial -lo#

-lat blade adial-lo#

/egree ofmixing

>er( small Small Large

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