Process and apparatus for afterburning exhaust gases of internal combustion engines

Claim 2

IN A PROCESS FOR THE CATALYTIC AFTERBURNING OF THE EXHAUST GASES OF INTERNAL COMBUSTION ENGINES, WITH SECONDARY AIR SUPPLY IN THE PRESENCE OF A CATALYST BEING OPERATIVE ONLY ABOVE A FIXED STARTING TEMPERATURE SUBSTANTIALLY ABOVE THE AMBIENT TEMPERATURE, THE IMPROVEMENT COMPRISING THE STEPS OF: SUPPLYING THE SECONDARY AIR FOR ADMIXTURE ONLY AFTER THE EXPIRATION OF A WARM-UP PHASE DETERMINED BY THE CATALYST TEMPERATURE DURING WHICH SUBSTANTIALLY ONLY EXHAUST GASES FLOW THROUGH SAID CATALYST; SUPPLYING AND ADMIXING THE SECONDARY AIR AT A RATE INCREASING WITH INCREASING CATALYST TEMPERATURE, BEGINNING WITH A CATALYST TEMPERATURE BELOW THE FIXED STARTING TEMPERATURE AND ABOVE AMBIENT TEMPERATURE, AND REACHING AT LEAST THE ADMIXTURE RATE OPERATIONAL STOICHIOMETRIC VALUE WHEN THE CATALYST HAS REACHED ESSENTIALLY THE FIXED STARTING TEMPERATURE.

Claim 3

AN INSTALLATION FOR THE CATALYTIC AFTERBURNING WITH SECONDARY AIR SUPPLY, OF THE EXHAUST GASES OF INTERNAL COMBUSTION ENGINES, COMPRISING: EXHAUST GAS LINE MEANS FOR COLLECTING AND CONDUCTING EXHAUST GASES FROM AN INTERNAL COMBUSTION ENGINE TO THE ATMOSPHERE INCLUDING A CATALYST HOUSING IN FLOW COMMUNICATION WITH THE EXHAUST GASES AND A CATALYST WITHIN SAID HOUSING IN FLOW COMMUNICATION HAVING A FIXED STARTING TEMPERATURE SUBSTANTIALLY ABOVE THE AMBIENT TEMPERATURE; SECONDARY AIR SUPPLY MEANS CONNECTED WITH SAID EXHAUST LINE MEANS FOR SUPPLYING SECONDARY AIR TO THE EXHAUST GASES; CONTROL MEANS FOR CONTROLLING THE SECONDARY AIR SUPPLY SO THAT SECONDARY AIR IS ADDED ONLY AFTER THE EXPIRATION OF A WARM-UP PHASE DETERMINED BY THE CATALYST TEMPERATURE DURING WHICH SUBSTANTIALLY ONLY EXHAUST GASES FLOW THROUGH SAID CATALYST HOUSING; SAID CONTROL MEANS INCLUDING TEMPERATURE RESPONSIVE MEANS FOR ADDING THE SECONDARY AIR SUBSTANTIALLY IN DEPENDENCE OF THE CATALYST TEMPERATURE AT A RATE INCREASING WITH INCREASING CATALYST TEMPERATURE, BEGINNING WITH A CATALYST TEMPERATURE BELOW THE FIXED STARTING TEMPERATURE FOR THE CATALYST AND SUBSTANTIALLY ABOVE THE AMBIENT TEMPERATURE, AND REACHING AT LEAST THE ADMIXTURE RATE OPERATIONAL STOICHIOMETRIC VALUE WHEN THE CATALYST HAS REACHED A FIXED STARTING TEMPERATURE THEREOF.

Claim 4

AN INSTALLATION FOR THE CATALYTIC AFTERBURNING WITH SECONDARY AIR SUPPLY, OF THE EXHAUST GASES OF INTERNAL COMBUSTION ENGINES, COMPRISING: EXHAUST GAS LINE MEANS FOR COLLECTING AND CONDUCTING EXHAUST GASES FROM AN INTERNAL COMBUSTION ENGINE TO THE ATMOSPHERE INCLUDING A CATALYST HOUSING IN FLOW COMMUNICATION WITH THE EXHAUST GASES AND A CATALYST WITHIN SAID HOUSING IN FLOW COMMUNICATION HAVING A FIXED STARTING TEMPERATURE SUBSTANTIALLY ABOVE THE AMBIENT TEMPERATURE; SECONDARY AIR SUPPLY MEANS CONNECTED WITH SAID EXHAUST LINE MEANS FOR SUPPLYING SECONDARY AIR TO THE EXHAUST GASES; CONTROL MEANS FOR CONTROLLING THE SECONDARY AIR SUPPLY SO THAT SECONDARY AIR IS ADDED ONLY AFTER THE EXPIRATION OF A WARM-UP PHASE DETERMINED BY THE CATALYST TEMPERATURE DURING WHICH SUBSTANTIALLY ONLY EXHAUST GASES FLOW THROUGH SAID CATALYST HOUSING; SAID CONTROL MEANS INCLUDING TEMPERATURE RESPONSIVE MEANS FOR ADDING THE SECONDARY AIR SUBSTANTIALLY IN DEPENDENCE OF THE CATALYST TEMPERATURE AT A RATE INCREASING WITH INCREASING CATALYST TEMPERATURE, BEGINNING WITH A CATALYST TEMPERATURE BELOW THE FIXED STARTING TEMPERATURE FOR THE CATALYST AND SUBSTANTIALLY ABOVE THE AMBIENT TEMPERATURE, AND REACHING AT LEAST THE ADMIXTURE RATE OPERATIONAL STOICHIOMETRIC VALUE WHEN THE CATALYST HAS REACHED A FIXED STARTING TEMPERATURE THEREOF.