METHOD OF REMOVING CLOGGING SUBSTANCE FROM HEAT EXCHANGER FOR APPARATUS FOR TREATING WASTE LIQUID FROM COG DESULFURIZATION

摘要

PURPOSE: To remove clogging sulfur by reducing the amount of a gas flowing through a hot bypass to below the amount thereof in an ordinary operation and thus elevating the temp. of a desulfurization waste liquid in a heat exchanger to thereby melt the clogging sulfur. ;CONSTITUTION: A desulfurization waste liquid discharged from a lower part of an absorption tower in a COG purification process is diluted so that the total calorific value in an apparatus for treating waste liquid from COG desulfurization remains constant, and then mixed with air for oxidation fed through air feed line 22. The mixture is fed to a heat exchanger A and then fed to a lower part 23 of a reaction tower R via heat exchangers B and C. A gas discharged from the top of the tower R is introduced into the heat exchanger C and fed to the exchangers B and A via a line 26 to heat the waste liquid. When the differential pressure in the exchanger B has increased, a hot-bypass valve 30 disposed in a line 29 extending from the line 26 is regulated to reduce the amount of the gas flowing through the hot bypass to below the amount thereof in an ordinary operation to thereby increase the amount of the gas fed to the exchanger B. Thus, the temp. of the waste liquid is elevated to melt the clogging sulfur.;COPYRIGHT: (C)1996,JPO