Swirl Fluidizer

SWIRL FLUIDIZER™ From paste to powder in one efficient step

The SWIRL FLUIDIZER™ For drying of pastes, filter cakes and viscous liquids When it comes to drying of pastes, filter

Extensive R&D work aimed at rendering

cakes and highly viscous liquids, the

the design suitable for an even larger

Niro SWIRL FLUIDIZER offers a cost-

range of applications has resulted in a

effective solution for obtaining a fine,

“new generation” SWIRL FLUIDIZER ,

homogeneous and non-agglomerated

mainly characterized by a conical lower

dry product – in one compact process

portion of the drying chamber, an even

Now the SWIRL FLUIDIZER is available

step.

more compact configuration and a

in a wide range of sizes from small

number of easily implemented optional

standardized pilot scale units to very

features for special applications.

large industrial installations.

TM

In this respect it is superior to most

TM

- Ability to handle very high drying temperatures - Capability to dry very heat-sensitive products TM

conventional processes. Contact dryers, band dryers, drum dryers and tray

Comprehensive modeling and testing

dryers are all drying processes charac-

as well as experience from many indus-

terized by long processing times and

trial scale installations have led to this

the need for costly post-treatment

new, flexible design, which offers the

such as milling.

following process advantages:

Also, the SWIRL FLUIDIZER’S ability TM

ability to handle even the most viscous liquids makes it an attractive alterna-

- Improved tolerance of changes in

Exhaust air

feed properties - Increased capacity

tive to spray drying for applications where dilution would be needed to obtain a pumpable and sprayable feed. The SWIRL FLUIDIZER offers the TM

Feed Drying chamber

following main process advantages: Bag filter - Ability to handle non-pumpable products - One stage combined drying and product treatment - Continuous operation

Feed system

- Compact layout requiring a minimum of space - Effective heat and mass transfer - Negligible heat loss - Maintenance-friendly design Hot air system

Process Concept

Drying Chamber

The arrangement of the lower part

Hot air system

The heart of the process is the Drying

of the drying chamber and the air dis-

Hot drying air is supplied to the air

Chamber where the feed disintegration

perser is also ideal for effective cooling

disperser at a controllable rate in order

and evaporation take place. The cham-

of hot internal surfaces, optionally

to ensure optimum thermal efficiency

ber consists of cylindrical upper and

allowing for drying of even very heat

of the drying process.

conical lower parts. For most applica-

sensitive products. The dried product

tions the feed is introduced into the

particles and the spent drying gas exit

Any available energy source can be

middle of the chamber. The hot drying

the drying chamber through the outlet

effectively utilized.

gas is fed into the chamber through

at the top of the chamber. Powder recovery and exhaust

the air disperser, which surrounds the lower conical portion of the drying

Feed tank

air cleaning system

chamber. The air disperser generates

The cylindrical feed tank is equipped

A bag filter is typically selected for dried

a tangential air flow which enters the

with a slowly rotating agitator, driven

product collection and cleaning of the

drying chamber from the bottom. There

from the bottom, which ensures a

spent drying air.

is an intense, swirling internal flow pat-

steady feed supply to the bottom-

tern of product and drying air within

mounted, speed-controlled dosing

the chamber, insuring uniform drying

screw. The screw transfers feed to the

and disintegration. The swirling flow

drying chamber at a continuous and

is assisted by the rotary disintegrator, a

controllable rate.

series of rotating blades that impact the product, reducing it to ever smaller particles; increasing the surface area in this manner increases the evaporation rate.

Process Configurations Selecting a configuration of a Niro

Process applications

SWIRL FLUIDIZER for the substantial

Recognized for its flexibility, the SWIRL

variety of applications is actually quite

FLUIDIZERTM has been used for a wide

easy. All plants are composed of stan-

range of applications in the chemical

dardized modules that are configured

industry, including:

TM

Open cycle system

Exhaust air Bag filter

with product-specific options. For instance, there could be a cooling system for heat-sensitive products,

- Agrochemicals – herbicides and fungicides

special features for particle size control

- Ceramics – silica, bentonite, kaolin

or the fundamental choice of an open

- Dyestuffs/pigments – iron oxides,

system versus a closed system.

Feed

titanium dioxides, phthalocyanines,

Dryer

zinc phosphates Open cycle system

Product

- Inorganic chemicals – metal carbon-

In the open system atmospheric air

ates and hydroxides, calcium

is used for drying. This system can

phosphates, zeolites

be applied even in cases where the product to be dried poses a potential dust explosion hazard, as the plant

- Organic chemicals – optical brighteners, flame retardants, polymers - Waste products – sludge, sediments

can be provided with pressure release or suppression systems.

Heater

The SWIRL FLUIDIZER is also well suited TM

Closed cycle system

Bag filter

for pharmaceutical and food industry applications. Whatever the application,

In the closed cycle system the oxygen

Niro’s comprehensive pilot plant facili-

content of the gaseous drying medium

ties in Columbia, Maryland are available

is either kept below a certain level or

for testing, trial and production.

eliminated by operating the plant in

Customers may draw on Niro’s com-

an inert mode using nitrogen as drying

prehensive expertise in drying and the

gas. Suppression of the oxygen content

experience we’ve gained in supplying

is often used where the product poses a

over 10,000 units worldwide since the

severe dust explosion hazard, whereas

company’s founding in 1933.

the inert nitrogen atmosphere is essen-

Scrubber/Condenser

Closed cycle system

Feed

Dryer

Product

Heater

tial when drying products containing a

Niro Inc. Process Engineering Division

A company of GEA Group Niro Inc. · 9165 Rumsey Road · Columbia · MD 21045 · USA Tel +1-410 997 8700 · Fax +1-410 997 5021 · E-mail: [email protected] · Web: www.niroinc.com

BNA 855/US September 2005

flammable solvent.