fluidiseerija

A fluidiseerija, or fluidizer in English, is a device or process used to transform solid particles into a fluid-like state. This is achieved by suspending the solid particles within a gas or liquid stream. When a gas is passed upwards through a bed of finely divided solid particles at a sufficient velocity, the drag force exerted by the gas on the particles overcomes the gravitational force. This causes the bed to expand, and the solid particles begin to move around freely, exhibiting characteristics similar to those of a liquid. The mixture of gas and solid particles behaves as a fluid, capable of flowing, mixing, and maintaining a level surface.

Fluidisation is a crucial phenomenon in various industrial applications. Fluidised beds are widely employed in chemical reactors, particularly in catalytic processes like the cracking of hydrocarbons in the petroleum industry. The fluidised bed offers excellent heat and mass transfer properties, leading to uniform temperature distribution and efficient contact between reactants and catalyst. They are also used in drying, roasting, calcining, and combustion processes. The efficiency of a fluidised bed depends on factors such as particle size and shape, gas velocity, and the density difference between the solid and the fluidizing medium. Different types of fluidisation exist, including bubbling fluidisation, turbulent fluidisation, and fast fluidisation, each offering distinct characteristics and suitability for specific applications.