Apparatus and method for collecting gas from aluminum furnaces

Claim 1

IN AN ALUMINUM REDUCTION FURNACE OF THE TYPE HAVING A POT ADAPTED TO RECEIVE A BATH OF CRYOLITE AND ALUMINA, A CASING ABOVE THE BATH ADAPTED TO HOLD AND GUIDE AN ELECTRODE AND VERTICAL CONTROL STUDS RUNNING DOWN INSIDE THE CASING ADAPTED TO ENTER THE ELECTRODE TO SUPPORT THE SAME AND CONDUCT CURRENT TO IT, MEANS FOR COLLECTING GASES GENERATED AROUND THE ELECTRODE COMPRISING A MEMBER RUNNING AROUND THE ELECTRODE EXTENDING OUT FROM THE CASING ADAPTED TO BE SEALED BY ALUMINA RELATIVE TO THE TOP ON A BATH IN THE POT TO FORM A SUBSTANTIALLY GAS-TIGHT SEAL BETWEEN SUCH MEMBER AND THE BATH WHEREBY GASES CAN BE COLLECTED BELOW SUCH MEMBER AND ADJACENT THE ELECTRODE AT A CONCENTRATION ABOVE THE EXPLOSIVE POINT, A SECOND MEMBER ALSO EXTENDING OUT ABOVE SUCH CASING ABOVE SAID FIRST MEMBER TO FORM A CHANNEL HAVING OPEN AREAS THROUGH WHICH GASES CAN BE SUCKED INTO SUCH CHANNEL AND SUCTION MEANS WHEREBY AIR AND ESCAPED FURNACE GASES CAN BE COLLECTED INTO A SECOND CHANNEL AT A CONCENTRATION BELOW THE EXPLOSIVE POINT, SAID SECOND MEMBER BEING SO POSITIONED THAT A LARGE OPEN AREA IS LEFT BETWEEN SAID MEMBER AND THE OUTER PERIPHERY OF THE FURNACE POT THROUGH WHICH ACCESS CAN BE HAD FOR WORKING ON THE SURFACES OF THE CHARGE IN THE POT AND THROUGH WHICH GASES MIGHT ESCAPE EXCEPT FOR THE SUCTION MEANS WHEREBY SUCH GASES ARE COLLECTED INTO THE SAID SECOND CHANNEL.