Method of and arrangement for increasing the alkali content in alkali-laden dusts of flue gases

Claim 1

IN COMBINATION WITH A CEMENT BURNING KILN: A FIRST DUST SEPARATOR HAVING AN INLET PORT AND AN OUTLET PORT AND ALSO HAVING A SEPARATED DUST DISCHARGE PORT, FIRST CONDUIT MEANS LEADING FROM SAID KILN TO SAID INLET PORT OF SAID SEPARATOR FOR CONVEYING FROM SAID KILN TO SAID SEPARATOR A CONTINUOUS FLOW OF FLUE GASES CARRYING DUST AND ALKALI VAPORS, SECOND CONDUIT MEANS LEADING FROM SAID DUST DISCHARGE PORT OF SAID FIRST SEPARATOR TO SAID KILN TO RETURN THE SEPARATED OUT DUST THERETO, A SECOND SEPARATOR HAVING AN INLET PORT, AN OUTLET PORT, AND A SEPARATED DUST DISCHARGE PORT, THIRD CONDUIT MEANS CONNECTING THE OUTLET PORT OF SAID FIRST DUST SEPARATOR WITH THE INLET PORT OF THE SECOND SEPARATOR, FOURTH CONDUIT MEANS LEADING FROM THE DUST DISCHARGE PORT OF SAID SECOND SEPARATOR TO SAID THIRD CONDUIT NEAR THE SAID OUTLET PORT OF SAID FIRST SEPARATOR FOR SUPPLYING DUST TO THE ALKALI VAPOR LADEN FLUE GASES LEAVING SAID FIRST SEPARATOR, A COOLER ASSOCIATED WITH SAID FOURTH CONDUIT MEANS TO COOL DUST PASSING THERETHROUGH TO A TEMPERATURE AT WHICH ALKALI VAPORS WILL CONDENSE THEREON, PORT MEANS FOR INTRODUCING DUST INTO SAID FOURTH CONDUIT MEANS, AND MEANS FOR WITHDRAWING ALKALI LADEN DUST FROM SAID DUST DISCHARGE PORT OF SAID SECOND SEPARATOR.