Kiln for ceramics

Claim 1

APPARATUS FOR RECARBONIZATION OF FORMED CERAMIC ARTICLES BY FIRING THE SAME TO CONVERT THE CALCIUM OXIDE THEREOF INTO CALCIUM CARBONATE COMPRISING MEANS FOR PASSING THE GASES OF COMBUSTION ACROSS THE ARTICLES FIRST IN A FIRING CHAMBER 9 FROM THE TOP DOWNWARDLY, THEN THROUGH A COMBUSTION GAS PASSAGE 14 AND THROUGH A PREFIRING CHAMBER 8 FROM THE BOTTOM UPWARDLY, AND THEN THROUGH ANOTHER COMBUSTION GAS PASSAGE 19 AND THROUGH A PREHEATING CHAMBER 7 FROM THE TOP DOWNWARDLY SO THAT IN THE PREHEATING CHAMBER THE TEMPERATURE WILL BE KEPT BETWEEN 150 AND 180*C. TO KEEP IT ABOVE THE DEWPOINT, IN COMBINATION WITH MEANS FOR SIMULTANEOUSLY PASSING GASES OF COMBUSTION WHICH CONTAIN CARBON DIOXIDE THROUGH A COOLING CHAMBER 10 TO RETARD COOLING DURING RECARBONIZATION WHILE THE TEMPERATURE OF THE COOLING CHAMBER IS ABOVE 550*C., AND MEANS FOR THEREAFTER BLOWING COOLING AIR ACROSS THE ARTICLES IN THE COOLING CHAMBER TO BRING THE TEMPERATURE DOWN TO BELOW 500*C.