Shell-and-tube type reactor for carrying out catalytic gaseous phase reactions and a procedure for operating the same

Shell-and-tube type reactor for carrying out catalytic gaseous phase reactions, comprising (a) a bundle of contact tubes, through which the relevant reaction gas mixture flows, that extend between a gas intake-side tube sheet and a gas output-side tube sheet, that contain a catalytic filling, and that are flushed by a heat transfer medium inside a surrounding reactor shell;

• (b) a gas intake hood and a gas outlet hood spanning the two tube sheets, respectively, for providing the relevant process gas to the contact tubes;
• and (c) a process gas main pipe for feeding the process gas into the gas intake hood, the improvement wherein the process gas main pipe comprises a first section, in which the process gas is in a non-explosive range, and in process gas flow direction behind it a second section, in which the process gas is in an explosive range;
• wherein the process gas main pipe comprises in its first section a check valve arrangement;
• and wherein the check valve arrangement and the gas intake-side tube sheet, and all parts therebetween, which bear the process gas pressure under normal operation conditions, are designed to withstand the maximum pressure caused by a deflagration or detonation.