In the fluidized bed, the drying energy is brought in and the fluidization is achieved by a cross flow of hot gases through a product layer. The fluidized beds can be designed gas-tight for inertization or solvent recovery. Additional contact exchangers may be installed within the product bed to increase the performance per volume. Designs with two or more drying temperature areas, or for final cooling of the product are possible.
Processes: Drying, cooling, heating, calcining or roasting.
Applications: free-flowing bulk solids, from fine powders to thick grain or short fibers which require a short to medium residence time.
Advantages: High evaporation rates with relatively short residence times, careful mechanical treatment, and absence of moving pieces (in static fluidized beds), flexible and adaptable design.
A fluidised bed is formed when a cross flow of hot gases is pressurised through a product layer resulting in its fluidisation. The drying/cooling air flows in an ascending direction through a grid or bored plate which equalises speed and pressure. The particles or granules are fluidised and drop on the grid/plate. The particles float on an air cushion and the product behaves like a boiling liquid.
The product entering the fluidisation area displaces the product already on the bed, until it overflows a final retention. The high turbulence around the fluidised particles prevents contact among them. Thus, and in spite of the high swirling agitation, this mechanical treatment is very gentle.
Our tailor-made fluidised beds allow for a variety of arrangements and combinations with other equipment. According to the customer’s requirements, Ingetecsa can supply a wide range of fluidised bed combinations: air-tight, expanded, self-emptying, ATEX, solvent-recovering, with internal exchangers, multi-stage, equipped with combined drying and cooling areas, among others. The following diagram shows an example of a fluidised bed with internal exchangers.