Stress Analysis of a 46-Inch Reactor Feed/Effluent Exchanger

Stress Engineering Services, Inc. performed a series of analyses for Brown Fintube to determine the mechanical behavior of its high performance 46-inch reactor feed/effluent exchanger. Initial efforts focused on the global behavior of the exchanger subjected to pressure and thermal loads, while the ultimate objective addressed potential leakage in the main body flange. Using finite element analyses incorporating shell, solid, and continuum models, Stress Engineering was able to demonstrate that the sealing load of the flanges could be maintained even with elevated bolt temperatures up to 400°F. Using the methods permitted by the ASME Boiler & Pressure Vessel Code, Section VIII, Division 2, linearized stresses were calculated. All calculated stress intensities were less than the Division 2 allowable stresses. Based upon the results of the analyses, the design of the main body flange also met the stress design criteria per Division 1 of the Code. This project was a clear demonstration on how analysis methods can be used to solve complex engineering problems that include a wide range of variables and operating conditions. The conservative calculation techniques of Division 1 of the Code were also confirmed in this work.