Spray Granulator

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Spray Granulator
By - Sasi Keerthi.G
(CH05B037) T.Kenneth Winfred (CH05B015) S.Ramacha
ndran (CH05B025) Virendra Kumar (CH05B047)
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Introduction

• What is Granulation?
• Granulation may be considered as a size
  enlargement process
• during which primary particles are formed into
  larger, physically
• strong agglomerates wherein the primary particles
  can still be
• identified.
• Objectives of granulation
• To improve the flow properties
• Densification
• To improve compression characteristics
• Prevention of segregation of the constituents

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In a more broader way , Granulation methods can
be classified as follows Granulation Process
Methodology Wet processes
Pan
granulation Spray drying
High shear granulation
(wet
massing) Fluid bed spray
granulation Dry processes
Slugging Roller
compaction
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Wet and Dry Granulation

• In wet granulation process, a granulating liquid
  is used to facilitate the agglomeration process.
• In dry granulation process, dry powder particles
  may be brought mechanically by compression into
  slugs or, more frequently these days, by roller
  compaction.

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What is Spray Granulation? Spray Granulation
occurs when a liquid solution is rapidly dried
over an active ingredient. This newly
encapsulated particle structure is harder and
denser, yielding particle properties that are
desirable in many applications. The newly formed
particle can be sprayed again and again creating
larger and larger spherical pellets that form in
successive onion like layers.
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In the granulation process, the particles are
conveyed through the inner partition into the
expansion chamber by the hot fluidizing air.
Gravity overcomes the force of the fluidized air
and the particles fall back into the outer
partition. The pneumatic atomizing nozzle in the
bottom center of the chamber introduces the
coating solution. This nozzle sprays upward
providing successive applications of coating to
the product.
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Mechanism

• Stages in Spray Granulation
• 1.Atomization of granulation liquid
• 2.Agglomeration of particles
• 3.Drying

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Atomization

• It is the process by which a liquid is
  disintegrated into many fine droplets, thereby
  yielding a high surface/mass ratio.
• This is achieved by supplying energy to the
  liquid in the form of kinetic energy, pressure
  energy, centrifugal energy etc.
• The most common form of atomization is hydraulic
  pressure nozzle atomization.
• The differential pressure drop across the orifice
  determines the mean droplet diameter.

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Agglomeration

• In this stage, the atomized granulating liquid is
  sprayed over the particles to facilitate the
  agglomeration.
• At low moisture contents, particles contact each
  other and adhere due to the formation of liquid
  bridges.
• Finally, droplets are formed when the liquid
  completely surrounds the granule.
• The strength of the droplet is dependent on the
  surface tension of the liquid phase.

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Agglomeration (contd..)

• The basic wet-granulated unit may be visualized
  as two particles and a liquid bridge that serves
  to hold the particles together by surface tension
  at air-liquid interface and by hydrostatic
  suction.

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Drying

• In this stage, the agglomerated droplets are
  brought into contact with heated gas for the
  evaporation to take place equally from the
  surface of all droplets.

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• Why Spray Granulation? ?Advantages
• Most spray granulation systems spray a liquid
  solution over a hot fluidized bed of active
  material. This process works by suspending the
  particles in a high velocity gas flow while
  applying the coating as a fine mist. Both liquid
  and solid powder coatings may be applied in this
  type of process.
• Some of the desirable product properties of the
  spray granulation process are
• Dust-free granules
• Spherical pellets
• Free flowing properties
• Good solubility
• Compact structure
• Less hygroscopic
• Less abrasive

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Different types of granulators Spray
Granulator The powder to be granulated is
suspended in the heated air of a fluid bed, and a
liquid binder sprayed from nozzles positioned
above High-shear Granulator The high-shear
granulation process combines the active powder
with a binder solution using a high-speed mixing
blade and chopper.
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• Typical Applications
• Spray granulators are widely used for forming
  materials in industries like chemicals, food
  products and pharmaceuticals. Its main purpose is
  to convert light, small powders into high-density
  free-flowing granulates.
• Some of its applications are given below
• Soup powder
• Sweeteners
• Tea
• Coffee
• Cocoa
• Organic acids
• Enzymes

Soya Sauce Gelatin Animal Drugs
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Fluid Bed Spray Granulator Nowadays, spray
granulation wherever used is mostly done in a
fluid bed. Fluid bed granules are very
homogeneous. All particles in the powder mix are
sprayed evenly with liquid starting materials.
The type of granulate (size, density, porosity)
can be influenced over a wide range by the
adjustment of various parameters.
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The particle formation in fluidized bed
granulation is influenced by numerous parameters
1. Moisture content in solids 2. Liquid spray
flow rate 3. Airflow rates 4. Atomization
pressure
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Batch fluid bed For Granulation in batch mode,
the dry starting product is placed in the product
container. Here it is mixed vigorously in the
heated gas stream, held in suspension and
agglomerated/granulated by spraying with a
suitable bonding material. The product is then
dried to the required end moisture content with
high heat and material transition coefficients.
PrincipleBatch fluid bed granulation,
Top Spray
PrincipleBatch fluid bed granulation,
Bottom Spray
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Continuous fluid bed Continuous granulators are
sub-divided into several granulation zones, which
are operated at different speeds and
temperatures, e.g. Granulation in the first and
second sections, drying in the third and cooling
at the end of the process chamber.
Principle
Principle Continuous fluid bed
granulation, Continuous fluid bed
granulation, Top Spray Bottom Spray
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Case Study I Port Kembla Steelworks Problem
A significant amount of material is stored in
the plants stockpile areas at any given time. In
the Raw Materials area, approximately 1.2million
tonnes of iron ore and other material is stored
in the primary and secondary yards. These
stockpiles have the potential to create
dust emissions as fine particles of material are
blown from the stockpiles into the air and out
into the community. Analysis Dust emissions
can be avoided if the particles that reside on
the surface were somehow made heavy or large.
This was achieved by granulation.
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Solution - The granulation process can be
achieved by installing sprayers that spray water
thereby increasing the size of fine particles
(dust). The installed water spray granulator
system effectively suppresses dust emissions from
the stockpiles under most weather conditions. The
spray system includes regular dampening of
stockpiles and spraying. Conclusion The
problem of dust emission was solved to a great
extent by the installation of the sprayers in the
stockpile area of Port Kembla Steelworks
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Bibliography http//www.glatt.com http//www.malve
rn.co.uk/ProcessEng/processes/granulation http//w
ww.pro-c-ept.com http//www.google.com
Thank you