Method of catalytically purifying exhaust gases and regenerating the catalyst utilized therein

Claim 1

A METHOD FOR THE PURIFICATION OF EXHAUST GASES FROM ENGINES USING LEADED GASOLINE, INVOLVING THE SIMULTANEOUS REMOVAL OF LEAD COMPOUNDS THEREFROM AND THE CATALYTIC OXIDATION OF OXIDIZABLE CONSTITUENTS THEREOF WHICH COMPRISES THE STEPS OF FLOWING SAID EXHAUST GASES AND AIR THROUGH A PURIFIER CONTAINING A BED OF RELATIVELY SMALL PELLETS OF OXIDATION CATALYST, MAINTAINING SAID BED AT AN ELEVATED TEMPERATURE SUCH AS TO INSURE THE CATALYTIC OXIDATION OF THE OXIDIZABLE CONSTITUENTS THEREOF, WHILE AT THE SAME TIME COLLECTING IN SAID BED A SUBSTANTIAL PORTION OF THE LEAD COMPOUNDS PRESENT IN THE EXHAUST GASES, CONTINUING THE OPERATION OF SAID PURIFIER UNTIL THE ACCUMULATION OF SAID LEAD COMPOUNDS SUBSTANTIALLY EFFECTS THE ACTIVITY OF THE OXIDATION CATALYST, AND PERIODICALLY FLOWING THROUGH THE PURIFIER IN CONTACT WITH SAID CATALYST BED AN AQUEOUS SOLUTION OF THE REAGENT CAPABLE OF DISSOLVING AND THEREBY REMOVING SAID LEAD COMPOUNDS WITHOUT DISSOLVING OR DAMAGING SAID CATALYST, DRAINING AND THEN FLUSHING SAID BED WITH WATER, EFFECTING DRYING OF SAID WET CATALYST BY OPERATING THE ENGINE AND PASSING THE HOT EXHAUST PRODUCTS MIXED WITH AIR THROUGH SAID WET CATALYST THEREBY EFFECTING PARTIAL DRYING AND CONCOMITANT PARTIAL ACTIVATION THEREOF BY MEANS OF THE SENSIBLE HEAT CONTENT OF SAID EXHAUST GASES, CONTINUING THE FLOW OF EXHAUST GASES AND AIR THROUGH SAID PARTIALLY ACTIVATED CATALYST THEREBY EFFECTING CATALYTIC OXIDATION OF A PORTION OF THE OXIDIZABLE CONSTITUENTS OF SAID GASES THEREBY RAPIDLY COMPLETING THE DRYING AND ACTIVATION OF THE REMAINDER OF SAID CATALYST BED.