VINAMILK 24 11 03

Modern Types of Spray
Drying Plants for the
Dairy & Food Industry


One-stage Drying (1CSD)

K64 KØ - 2 -


Drying of droplets in hot air
Temperature oC

• Relation between air temperature, product temperature and drying time
500
400
300

Air temperature

200
100

Product temperature

Start of drying
1
2
3

4

5

1
2
3
4
5

End of drying
Heat transfer to solids by convection.
Internal heat transfer.
Evaporation.
Internal diffusion of water vapour.
External mass transfer by convection.


Typical temperature profile measured
in the drying chamber
200 -110 o C
110 -105 o C
105 -100 o C
100 - 95 o C
95 - 80 o C
80 - 60 o C
60 -

o

C

T out : 200 o C
T in :

100 o C


Two-stage Drying (2CSD)

powder outlet

K64 KØ - 5 -


3-stage spray dryer with fines return

powder outlet

K64 KØ - 6 -


Spray bed dryer with fines return

K64 KØ - 7 -


Mollier diagram


Tall-form spray drying plant with bustle
(TFDB) and external fluid bed

K64 KØ - 9 -


3-stage Conical Spray Dryer (3CSD)
1

3

2

10
9

5

4
6
7
8
8
8

K64 KØ - 10 -

1
2
3
4
5

6

Air heater
Air distributor
Atomizer
Feed System
Drying chamber
Integrated
fluid bed
7 External fluid bed
8 Fluid bed air
supply systems
9 Cyclone
10 Bag filter


Indirect air heater
Process air outlet

Combustion air inlet Flue gas outlet

Burner

Liquid-coupled
heat exchanger

Recuperator
Exhaust duct
Concentric
cylinders

Combustion
chamber

Process air inlet Fan
K64 KØ - 11 -

Preheater

Inspection door / Pressure relief valve


Air distributor designed for centrifugal
as well as nozzle atomizer
Uniform air distribution.
Designed for nozzle or
centrifugal atomization
and fines return.
Easy change of
atomizer type.

K64 KØ - 12 -


Tall form computer flows


Optimized air flow in single-stage
spray drying plant with bottom outlet

K64 KØ - 14 -

Optimized air flow in three-stage
spray drying plant with bottom outlet

High thermal efficiency
Agglomerated as well as high
bulk density powder

K64 KØ - 15 -


Optimized air flow in Spray Bed Dryer (SBD)
Inlet air

Outlet air

Centrifugal atomizer
and pressure nozzle
capability.
Technical superior
air distributor.

K64 KØ - 16 -

Inlet air


Spray bed dryer with nozzle atomizer
computer flow

Air distributor designed for centrifugal
as well as nozzle atomizer
Uniform air distribution.
Designed for nozzle or
centrifugal atomization
and fines return.
Easy change of
atomizer type.

K64 KØ - 18 -


Air distributor with centrifugal atomizer

K64 KØ - 19 -


Centrifugal atomization


Centrifugal Atomizers

K64 KØ - 21 -


Atomizer wheel with nozzle inserts

K64 KØ - 22 -

HP nozzle atomizer
Product
Product

Fines

The HP nozzle atomizer
is flexible and unique,
suitable for
agglomeration

Air
distributor

Peripheral nozzle

Central nozzle

K64 KØ - 23 -


Nozzle Atomizer in stand

K64 KØ - 24 -


Centrifugal atomizer
Advantages

•

Is uncomplicated with regard to operation

•

Insensitive to changes in capacity (with the capacity
range)

•

Insensitive to changes in viscosity

•

Insensitive to some impurities in feed

•

Requires a “simple” feed pump

•

Can atomize abrasive products

•

Easy to start-up on water

•

Easy to clean

K64 KØ - 25 -