Heat-storage breather system

Claim 1

IN A HEAT-STORAGE SYSTEM COMPRISING A CONTAINER, HEAT-STORAGE MATERIAL IN SAID CONTAINER WITH A SPACE ABOVE THE MATERIAL IN THE UPPER PART OF THE CONTAINER, SAID MATERIAL BEING ABSORPTIVE OF CARBON DIOXIDE TO FORM CARBONATES HAVING MELTING POINTS HIGHER THAN THAT OF THE MATERIAL, CONDUIT MEANS THROUGH WHICH FLUID MAY BE CIRCULATED PAST THE CONTAINER TO DRAW HEAT FROM THE MATERIAL, A WALL OF INSULATION AROUND THE CONTAINER, AND TUBULAR BREATHER MEANS EXTENDING FROM SAID SPACE THROUGH SAID WALL, SAID TUBULAR MEANS INCLUDING A TUBE OF SMALL DIAMETER AND A TUBE OF RELATIVELY LARGE DIAMETER, THE OUTER END OF THE LARGE TUBE BEING CLOSED EXCEPT FOR AN OPENING WHICH IS SEALED AROUND THE SMALL TUBE AND THE CONTAINER BEING CLOSED EXCEPT FOR AN OPENING SEALED AROUND THE LARGE TUBE, SAID MATERIAL TENDING TO CREEP OUTWARDLY ALONG THE SURFACE OF SAID LARGE TUBE WHEN MOLTEN, THE LARGE TUBE EXTENDING INTO SAID WALL BEYOND THE LOCATION WHERE ITS TEMPERATURE REACHES THE MELTING POINT OF SAID MATERIAL, WHEREBY IN CREEPING ALONG SAID LARGE TUBE THE MATERIAL CANNOT ENTER THE SMALL TUBE.