Secadores de leito fluidizado

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Secadores de leito fluidizado

Os secadores e resfriadores de leito fluidizado Metso são usados para secagem e resfriamento de vários tipos de materiais.

Através do fenômeno da fluidização, o material passa a agir como um fluido, com o gás passando pela velocidade correta através do leito. Isso gera um contato excelente entre sólidos e gás, resultando em alta transferência de calor parasecagem rápida. Temos secadores de leito fluidizado com capacidade de secagem de até 300 tph.

Aplicação dos secadores de leito fluidizado: Aplicação dos secadores de leito fluidizado:
* Areia (mineral e em fundições)
* Minerais (calcário, magnetita, gesso, cobre, sal, ferro)
* Sementes e grãos (grama, trigo, aveia)
* Misturas químicas

Principais benefícios dos secadores deleito fluidizado:
* Habilidade para secar materiais pequenos e finos
* Baixa manutenção
* Boa agitação
* Alta capacidade

A Metso já instalou mais de 100 sistemas de leito fluidizado sob as marcas Pyrotherm e Allis-Chalmers.



Vibrating _uid bed dryer for cooked grains Fluid bed cooler for sugar incorporating cooling tubes

Fluidised Bed Dryers andCoolers
Our Fluidised Beds are in widespread use throughout the
process industries for drying, cooling and calcining of
powders, crystals and granules.
Materials processed in a Fluidised Bed Dryer or Cooler _oat on a
cushion of air or gas. The hot or cold air is supplied to the bed
through a special perforated distributor plate and _ows
through the layer (or bed) of solids at a velocitysu_cient to
support the weight of particles in a _uidised state. Bubbles
form and collapse within the _uidised bed of material
promoting intense particle movement. In this state, the solids
behave like a free-_owing boiling liquid. Very high heat and
mass transfer values are obtained as a result of the intimate
contact with the solids and di_erential velocities between
individual particles andthe _uidising gas.
The design of the distributor plate ensures that the _uidising
gas is evenly distributed across the area of the bed. The gas
velocity is such that only the very _ne material fraction is
carried over to the dust collection equipment. A high
turndown ratio of production capacity is possible and
_uctuations of the feed rate are easily absorbed. In most cases
there are nomoving parts in contact with the product.
Fluidised Beds can also be built with:
• drying and cooling zones in the same unit
• multiple stages for drying and conditioning of heat
sensitive materials
• exhaust gas recycle, either between sections or full recycle
when, for example, toxic materials are processed.
Two _uid bed dryer/coolers for sand
Fluid bed cooler for sugar incorporating coolingtubes
Vibrating _uid bed dryer for cooked grains
Fluid Bed with in-bed
tubes & gas recycle
Dry
Product
Dry
Product
Recycle
Steam
Steam
Tubes Tubes
Water
Condensate
Cooler
Section
Feed
Contact Tubes
A deep fluidised bed fitted with contact tubes offers significant
improvements in three key areas: emissions, plant size and
operating costs. Up to 90% of the heat can besupplied (drying)
or removed (cooling) by the steam or fluid circulating through
the tubes. The result is an enormous reduction in airflow
compared with the typical standard fluidised bed plant. Contact
fluidised beds are best suited to non-cohesive materials.
Vibrating Beds
Many materials begin at or pass through a sticky, softening or
cohesive phase during processing. Vibrating beds areextremely
effective in keeping the material in a live fluidised state during
this transitory phase. They are also suitable for materials
which have a wider particle distribution.
Stirred Beds
Where materials at the feed point are particularly sticky, a
rotating agitator can be incorporated within the first drying
section of the bed. This slow moving device serves to gently
agitate the wet...
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