Process for cleaning slurry coolers

Claim 1

THE PROCESS FOR OPERATING A HEAT EXCHANGER WHEREIN A REACTION SYSTEM COMPRISING A SLURRY IS COOLED BY PASSING SAID SLURRY THROUGH ONE SIDE OF SAID HEAT EXCHANGE AND PASSING A COOLER LIQUID THROUGH THE OTHER SIDE OF SAID HEAT EXCHANGER. THE IMPROVEMENT WHICH CONSIST OF: REGULATING THE COMPOSITION OF SAID SLURRY BY CONDUCTING THE OXIDATION OF METAXYLENE BY AIR TO ISOPHTHALIC ACID IN AN AQUEOUS ACETIC ACID SOLVENT CONTAINING A SOLUTION OF COBALT AS CATALYST, SAID SLURRY TENDING TO DEPOSIT PLATING DEPOSITS OF SLURRIED MATERIAL ONTO THE SURFACE OF THE PROCESS SIDE OF THE EXCHANGER, SAID PLATING COMPRISING ORGANIC COMPOUNDS AND ACIDS, REGULATING THE TEMPERATURE OF THE REACTION SYSTEM IN THE HEAT EXCHANGER TO MAINTAIN A REACTION TEMPERATURE OF FROM ABOUT 200*F TO 275*F. BY CIRCULATING COOLING WATER IN SAID HEAT EXCHANGER, AND OPERATING THE HEAT EXCHANGER IN AN IMPROVED MANNER BY PERIODICALLY SUBSTITUTING LOW PRESSURE STEAM FOR SAID COOLING WATER TO REMOVE PLATING DEPOSITS OF SLURRIED MATERIAL FROM THE SURFACE OF THE PROCESS SIDE OF THE EXCHANGER, THE TEMPERATURE OF THE LOW PRESSURE STEAM BEING LESS THAN THE MELTING POINT OF ISOPHTHALIC ACID BUT SUFFICIENTLY HOT TO ALTER THE ADHESION OF SUCH DEPOSITS TO PERMIT SUCH DEPOSITS TO BECOME DISPERSED AND WITHDRAWN AS A COMPONENT OF WITHDRAWN SLURRY, SAID LOW PRESSURE STEAM HEATING THE HEAT EXCHANGER AND CIRCULATING SLURRY TO A TEMPERATURE OF ABOUT 200*F.