Comessa S.A. products

Flash drying works on the principle of pneumatic transport using hot air. Wet product is introduced into a high velocity air stream through a special Venturi feeder.

Fluidization confers to a divided solid the properties of a fluid. Products with a wide particle size distribution or including large particles, cannot be processed in a static fluidization equipment. It is the same for products discharged from centrifuges which are sticky or include lumps and which will not permit treatment by direct fluidization. Comessa developed the vibrating fluidized bed to solve most of these delicate drying problems. In such case, vibration insures a better fluidization and allows transport of largest particles or lumps.

In complementto standard static or vibrating fluidized beds, suitable to work up to 400°C COMESSA designs also high temperature fluid beds up to 950°C. This batch fluidized bed is constituted by a metallic cylindrical reactor heated through the wall, allowing an internal controlled atmosphere, independent from heating load. The retort can be externally heated by radiation with electrical coils or by hot gases.

The fluidization is a state of dynamic balance of a divided solid in an ascending moving gas. It confers hydraulic properties to solids (angle of repose equal to zero, easy spreading, total filling of a receiver in which the product is fluidized). Such method of bringing in contact a solid with a gas, allows high mass and heat transfers. Mechanical energy transferred by gas to the particles is low enough to prevent attrition. Crystals for instance will remain bright and will keep sharp edges.