Process for producing anhydrous sodium sulfate

Claim 1

IN A PROCESS FOR PRODUCING ANHYDROUS SODIUM SULFATE, THE STEPS CONSISTING IN DISCHARGING A CONTINUOUS STREAM OF A SATURATED OF SODIUM SULFRATE DOWNWARDLY AS A THIN TUBULAR LIQUID FILM FROM THE UPPER END OF A COMBUSTION ZONE TO THE LOWER END THEREOF AND SPRAYING ADDITIONAL SATURATED SOLUTION OF SODIUM SULFATE INTO THE FREE SPACE OF SAID ZONE TO EVAPORATE WATER FROM SAID SOLUTION COLLECTING SAID SOLUTION SATURATED WITH RESPECT TO SODIUM SULFATE AND AT A TEMPERATURE ABOVE THE TRANSITION TEMPERATURE OF NA2SO4, 10H2O TO NA2SO4 AND H2O, AT A LOWER PORTION OF SAID ZONE, REMOVING SAID SOLUTION FROM SAID ZONE, THEN MIXING SODIUM SULFATE DECAHYDRATE INTO SAID SOLUTION IN AN AMOUNT SUFFICIENT TO REPLACE THE WATER REMOVED IN THE AFORESAID EVAPORATION STEP UPON MELTING OF THE DECAHYDRATE IN SAID