Presentation On

“Fluidization”

By:- Rushikesh G. Satote (20110448)

S. Y. B.Tech Chemical Engg.

Under The Guidance ofDr. Vijay Babu.

Outline:

Fluidization

Properties

Types of Bed

Designs

Applications

Advantages

Steps in fluidization

What is Fluidization?

Process in which fixed solid bed behaves like liquid showing fluidity.

Pop-corn Hopper theory

When pressure drop across bed balances gravitational pull on it bed becomes fluidized.

Properties:

High surface area contact between fluid & solid.

High level of intermixing of particulate phase.

High relative velocity between fluid phase & dispersed solids

Affecting Factors:

Size, roughness & density of particles.

Temperature, pressure & humidity of gas

Important terms:

Eurgen’s equation

Minimum fluidization velocity

Minimum porosity

Slugging velocity

Disengagement space

Superficial velocity

Entrainment & minimum bubbling velocity

Types:

Particulate fluidization:In it density difference of solid and fluid is small.

Ex. Liquid-solid system

Aggregative fluidization:When density difference of solid & fluid is large.

Ex. Gas-solid system

Boiling bed fluidization, spouted bed fluidization, incipient fluidization, centrifugal fluidized bed,recirculating fluidized bed

Major parts of fluidization system:

Fluidization vessel & bed-portion.

Freeboard (disengagement space )

Gas distributor

Solid feeder & discharge

Gas supply

Instrumentation

Applications:

Many of catalytic chemical reactions like catalytic cracking of crude oil in smaller fractions.

In coating.

Drying of suspensions & moist cakes.

Roasting of ores drying.

Fluidized leaching.

Size reduction

Advantages:

Temperature uniformity

Good heat transfer

Transportability

Provides intimate contact

Disadvantages:

Attrition means erosion of bed particles & equipment.

Recovery of the fines.

High capital & maintenance cost.

Future Scope:

Effective utilization of the fuels.

Chemical looping combustion

Use of incinerators in power plants