Method of removing so{11 {11 and h{11 so{11 {11 mist from a gas stream

Claim 1

IN THE PRODUCTION OF SULFURIC ACID WHEREIN: A GAS STREAM CONTAINING SULFUR DIOXIDE IS SUBJECTED TO CONTACT CATALYSIS TO FORM SULFUR TRIOXIDE THEREIN, THE SULFUR TRIXIE IS AT LEAST IN PART REMOVED FROM THE GAS STREAM BY ABSORPTION IN AT LEAST ONE ABSORBER STAGE BY EFFECTING CONTACT OF THE GAS STREAM WITH SULFURIC ACID THEREIN, AND A DRY CONTACT-PROCESS END GAS CONTAINING SULFUR TRIOXIDE AND/OR SULFURIC ACID MIST EMERGES FROM THE FINAL ABSORBER STAGE, THE IMPROVEMENT WHICH CONSISTS OF A METHOD OF REMOVING SULFUR TRIOXIDE AND/OR SULFURIC ACID MIST FROM SAID DRY CONTACT-PROCESS END GAS, SAID IMPROVEMENT COMPRISING THE STEPS OF: A. INTIMATELY CONTACTING SAID DRY-PROCESS END GAS SUBSEQUENT TO THE FINAL ABOSRBER STAGE WITH A WATER-DILUTED SULFURIC ACID TREATING SOLUTION HAVING A SULFURIC ACID CONCENTRATION OF 40 TO 90 PERCENT BY WEIGHT TO INCREASE THE WATER-VAPOR CONTENT OF SAID END GAS, TO CONVERT SLFUR TRIOXIDE THEREIN TO SULFURIC ACID AND TO CONVERT SULFURIC ACID MIST THEREIN TO SEPARABLE SULFURIC ACID DROPLETS, AND TO FORM A MIXUTRE OF SULFURIC ACID LIQUID PHASE AND A GAS PHASE, SAID WATER-DILUTED SULFURIC ACID TREATING SOLUTION BEING INJECTED INTO SAID END GAS IN A DOWNWARDLY DIRECTED VENTURI TUBE TO PRODUCE A DOWNWARDLY FLOW OF SAID MIXTURE OF SAID PHASE, AND FURTHER PASSING SAID DOWNWARDLY FLOWING MIXTURE THROUGH A PACKING LAYER DOWNSTREAM OF SAID VENTURI TUBE; B. SEBSEQUENT TO THE CONTACT OF SAID DRYING CONTACT-PROCESS SUBSEQUENT TO THE CONTACT OF SAID DRYING CONTACT-PROCESS END GAS WITH SAID SULFURIC ACID TREATING SOLUTION AHVING SAID SULFURIC ACID CONCENTRATION OF 40 TO 90 PERCENT BY WEIGHT TO RECOVER SULFURIC ACID AS THE LIQUID PHASE, SAID LIQUID AND GAS PHASE BEING SEPARATED BY COLLECTING PART OF SAID LIQUID PHASE BELOW SAID PACKING LAYER, DEFLECTING SAID GAS PHASE AT RIGHT ANGLES DOWNSTREAM OF SAID PACKING LAYER, AND PASSING SAID DEFLECTED GAS STREAM THROUGH A FURTHER PACKING LAYER FOR REMOVAL OF ADDITIONAL QUANTITIES OF SAID LIQUID PHASE THEREFROM; C. DISCHARGING THE GAS PHASE AFTER SEPARATION OF THE LIQUID PHASE THEREFROM IN STEP (B) AS AN EXHAUST GAS SUBSTANTIALLY FREE FROM SULFURIC ACID; AND HEATING SAID END GAS PRIOR TO CONTACT OF ACID TREATING SOLUTION THEREWITH IN STEP (A) AND SUBSEQUENT TO SAID FINAL ABSORBER STAGE.