Simulation of the Gas Flow Distribution in the Inlet Chamber of the Conventional and Bathtub TLE

摘要

The Bathtub transfer line exchanger differs from the conventional TLE in the arrangement of the tubes and the shape of the gas inlet chamber. Multiple gas inlet nozzles, reduced volume and an optimized internal shape of the gas inlet chamber have a favorable effect on the gas velocity profile, residence time of gas and deposits of coke. Numerous CFD calculations have been carried out for conventional and bathtub gas inlet chambers. Results shows, that in the bathtub cooler the mean residence time of the gas and coke particle can be reduced to less, than 50 % of the residence time of the gas and coke particles in the conventional TLE's. Protective grids, which main purpose is to protect the ovalheader tubesheet from erosion have also positive influence on the gas flow distribution into the individual tubes. Pressure and gas velocity profiles shown on the diagrams demonstrate the advantages and specific differences between both types of coolers. Results from theoretical calculations have been confirmed in actual operation on both types of coolers.