Heat exchange system having slide bushing for tube expansion

摘要

A tube-and-shell heat exchanger system is disclosed which provides for partial heating of the cooler stream as it flows through a first compartment in the shell and conducting the partially heated stream to the outlet end of a second compartment in the shell to maintain the outlet end of the tubes at a higher temperature. The higher temperature at the outlet ends of the tubes avoids rapid fouling of tubes near the outflow end. There are provided slide bushings for tubes passing between the compartments in the shell. The slide bushings make possible heating of greater volumes of the cooler stream and maintaining the outlet end of tubes at higher temperature, while extracting more heat from the hot stream. The slide bushings provided may also be used to replace conventional expansion joints. The system is particularly useful in carbon black plants, where the hot smoke stream containing combustion gases and carbon black is used to preheat the air stream used for burning fuel in the reactor of the plant.