METHOD FOR CONTROLLING THE HEAT LEVEL OF A SOLID IN A HEAT EXCHANGER WITH CYLINDRICAL TUBE LAYERS

摘要

Method for controlling the heat level during the continuous processing in a fluidized bed of a pulverulent solid, whereby said solid is processed in a fluidized bed processing zone, at least a portion of the solid is drawn off from the zone and conveyed to an external heat exchanger (21) containing at least a bundle (22) of heat exchanging tubes in which a vaporizable cooling fluid circulates, after which a thermal control process is effected in a fluidized bed by indirect heat exchange with the fluid, and the heat controlled portion is drawn off to be recycled in the processing zone or in another processing zone (1). In particular, the portion of the solid is circulated downwards by means of an inert or non-inert fludization fluid, in the fludized bed and over the tube bundle (22) which is wound in such a way that the solids stream crosses the tubes, and the cooling liquid is circulated in a single direction in the tube bundle. The invention applies to catalytic cracking of petroleum feedstocks.