Expertise in granular Products processing
The High Temperature Fluid Bed     In addition to standard Static or Vibrating Fluid Beds, able to work up to 400°C, comessa designs also High Temperature Fluid Beds suitable up to 1000°C. Two types are available : Direct or Indirect Heated. click the picture to enlarge           1) The Direct Heated Fluid Bed The Direct Heated High Temperature Fluid Bed is constituted by a tight casing separated in two parts by the fluidization plate. Considering the internal temperatures, the casing will be lined by a refractory brick concrete layer. The fluidization plate itself will be manufactured from refractory steel or concrete with suitable nozzles in conformity with product requirements.   The unit is continuously supplied and product is discharged by overflow due to the fluidization effect. The heat is brought by a hot gas generator using fuel or gas as heating medium or by direct injection of the heating medium in the Fluid Bed. The exhausted fine particles are caught in a dedusting system ie. cyclone followed usually by a scrubber. This kind of installation allows processing of pulverulent particles located in a range of 1 to 10 mm. Maximum temperature in such process can reach 1000°C.   Main applications : Pyrite roasting, Phosphate calcining, Coal activation, Incineration of sludges, Ore calcining, Pyrolyse of plastic wastes.. click the picture to enlarge           2) The Indirect Heated Fluid Bed The unit is constituted by a metallic cylindrical reactor vessel fifted a special plate allowing an optimum fluidization. Heating through the wall of the retort is achieved by radiation. Exhaust gases are cleaned by a special filter made from porous metal cartridges. Fluidization will generate an important stirring between the treatment phases and therefore a very homogeneous temperature. Precise temperature cycle can be followed by a programmed controller.   This filter is divided in four quadrants. At any time, three of the quadrants are onstream, while one is being backflushed by a pulse of air or other gas. The treated product is discharged by a special high temperature valve in a cooling system which can be a Fluid Bed Cooler. Usually this type of process is batchwise, however it can be arranged for continuous processing. Such installations allow treatment of particles under 30 microns. Maximum operating temperature will be 1000°C Within the framework of applications on the desulfuration of pyrites, comessa was brought to develop a tight Static Fluid Bed where the gas process is preheated by a standard heat exchanger and the booster of thermal contribution is given by radiant tubes in silicon carbide. The circuit of process gas is foreseen under close loop. The High temperature Fluid Bed is constituted by a Carbon Steel casing fitted internally by a tight refractory lining.   Main applications : Pyrite desulphurisation, Metallic oxides reduction ( Iron, Nickel), Catalysts reactivation, Pyrolysis of wastes, Alumina and Silica calcination. click the picture to enlarge