A system for in direct heat exchange with particulate material permits the use of small catalyst transfer pipes increased spacing between the vessel supplying particulate material and the heat exchanger and complete isolation of the heat exchanger from high temperature particulate materials for repair while the source of particulate continues in operation. The arrangement uses a cyclic movement of fluidized particulate material from a particle bed through a supply line to a heat exchanger and back from the heat exchanger to a particulate bed through a return line. Pressurization and depressurization of a particulate material containing volume within the heat exchanger creates the cyclic flow of particulate material in through the supply line and out through the return line. This system is particularly beneficial for the fluidized catalytic cracking process and removes essentially all limitations on the distance between a catalyst cooler and the regenerator. With this system a pair of coolers can be located at grade for an unvarying supply of steam and safely isolated for servicing of one or both of the exchangers while the regenerator is on stream.
