Process and apparatus for recovering waste gases from converters in steel works

Claim 1

A PROCESS FOR THE RECOVERY OF GASES EMANATING FROM A PIG IRON REFINING ZONE, COMPRISING THE STEPS OF RECOVERING SAID GASES IN A CHAMBER ABOVE SAID REFINING ZONE, SAID CHAMBER HAVING A WALL DEFINING AN OPEN BOTTOM ZONE IN COMMUNICATION WITH THE SURROUNDING AIR; DRAWING THE RECOVERED GASES FROM THE CHAMBER THROUGH AN EXHAUST CONDUIT REMOTE FROM THE OPEN BOTTOM ZONE, THE RECOVERED GASES FORMING A SEAL WITH THE WALL OF THE CHAMBER AGAINST ENTRY OF ATMOSPERIC AIR IN A HORIZONTAL PLANE IN THE LOWER PART OF THE OPEN BOTTOM ZONE, MEASURING TEMPERATURE FLUCTUATIONS IN SAID OPEN BOTTOM ZONE CLOSE TO THE REFINING ZONE, CONTROLLING THE DRAUGHT OF THE GASES THROUGH THE EXHAUST CONDUIT IN RESPONSE TO THE MEASURED TEMPERATURE FLUCTUATIONS IN EXCESS OF A PREDETERMINED TEMPERATURE FLUCTUATION RANGE WHEREBY THE TEMPERATURE AT THE MEASURED LEVEL IS RE-ESTABLISHED WITHIN SIAD RANGE AND SAID SEALING PLANE IS MAINTAINED AT A SUBSTANTIALLY CONSTANT LEVEL TO MINIMIZE LEAKS OF SURROUNDING AIR AND RECOVERED GASES BEYOND SAID PLANE.