Computer-Designed Vacuum Vessels

Abstract

Today a wide variety of chemical and petrochemical processes require equipment that operates under partial vacuum. The ASME Code for Unfired Pressure Vessels, Section VIII, sets forth a method for designing these vessels by trial and error, leaving any consideration for economics up to the designer, who quite often neglects this because he is pressed for time. For this reason it became apparent that a computerized design was the only solution since the computer can perform this time-consuming, tedious, and repetitive calculation quickly and systematically. The computer cannot make use of the vacuum charts in their present form; thus the IBM program “STUFF,” Sixteen Twenty Universal Function Filter, was used to obtain formulas that replace the charts. With this program an optimum design is obtained each time, thus realizing a savings for each vessel processed through it, both in material and time. The following paper describes some of the problems encountered in trying to program the charts and how they were solved. A specific formula is set up showing the method used, and a hand-calculated problem is compared with the same problem processed through the program.