Electrical apparatus using pressurized air as a dielectric and having air drying means incorporated therein

Claim 1

AN AIR BLAST ELECTRIC CIRCUIT BREAKER COMPRISING: (A) A TANK CONTAINING AIR AT A HIGH NORMAL OPERATING PRESSURE OF AT LEAST SEVERAL HUNDRED P.S.I., (B) METALLIC PARTS AND INSULATING PARTS WITHIN SAID TANK HAVING SURFACES THAT ARE UNDER HIGH ELECTRIC STRESS IN COMPARISON TO THE ELECTRIC STRESS ADJACENT THE INTERNAL SURFACE OF THE TANK, (C) MEANS FOR RELEASING PRESSURIZED AIR FROM SAID TANK UPON OPERATION OF SAID CIRCUIT BREAKER, (D) SUPPLY MEANS FOR SUPPLYING AIR TO SAID TANK TO COMPENSATE FOR AIR RELEASED THEREFROM, (D) SAID SUPPLY MEANS COMPRISING: A SOURCE OF SUBSTANTIALLY SATURATED AIR AT A PRESSURE HIGHER THAN SAID NORMAL OPERATING PRESSURE, MEANS CONNECTING SAID SOURCE TO SAID TANK, A NORMALLY-CLOSED REGULATOR VALVE CONTROLLING THE FLOW OF AIR THROUGH SAID CONNECTING MEANS, AND MEANS FOR OPENING SAID VALVE IN RESPONSIVE TO A DROP OF PRESSURE INSIDE SAID TANK TO A PREDETERMINED LEVEL, (E) MEANS COMPRISING SAID REGULATOR VALVE FOR REDUCING THE RELATIVE HUMIDITY OF AIR PASSING THROUGH SAID CONNECTING MEANS AND FOR LIMITING THE RELATIVE HUMIDITY OF THE AIR ENTERING SAID TANK TO A VALUE LESS THAN 50 PERECENT, (E) SAID REGULATOR VALVE EFFECTING SAID REDUCTION IN RELATIVE HUMIDITY BY EXPANDING AIR THERETHROUGH UPON VALVE-OPENING, (F) A QUANTITY OF DESICCANT MATERIAL WITHIN SAID TANK THAT IS OF SUCH CHARACTER THAT IT RELEASES ADSORBED MOISTURE TO SURROUNDING AIR WHEN THE VAPOR PRESSURE OF THE ADSORBED MOISTURE EXCEEDS THE PARTIAL PRESSURE OF THE MOISTURE IN THE AIR, (G) THE SATURATION CHARACTERISTICS OF SAID DESICCANT MATERIAL AT ROOM TEMPERATURE BEING SUCH THAT THE DESICCANT IS UNSATURATED WHEN THE EQUILIBRIUM RELATIVE HUMIDITY OF AIR SURROUNDING IT IS MAINTAINED AS HIGH AS 50 PERCENT, (H) SAID DESICCANT MATERIAL HAVING THE ADDITIONAL CHARACTERISTIC OF MAINTAINING AN APPROXIMATELY CONSTANT RELATIVE HUMIDITY AT EQUILIBRIUM TEMPERATURES OF BETWEEN 30 DEGREES F. AND 200 DEGREES F. WHEN ITS WATER CONTENT IS FIXED. (I) THE WEIGHT OF DESICCANT PRESENT IN SAID TANK BEING SO HIGH THAT THE DESICCANT CAN ABSORB THE MAXIMUM AMOUNT OF MOISTURE CONTAINED IN ONE TANKFUL OF AIR AT SAID HIGH NORMAL OPERATING PRESSURE AND AT THE HIGHEST EQUILIBRIUM OPERATING TEMPERATURE OF SAID CIRCUIT BREAKER WITHOUT MORE THAN A FEW PERCENT INCREASE IN SAID DESICCANT WEIGHT, (J) THE SURFACE OF SAID DESICCANT EXPOSED TO AIR IN SAID TANK BEING SO LARGE THAT THE DESICCANT ADSORBS MOISTURE QUICKLY ENOUGH TO PREVENT MOISTURE-CONDENSATION ON SAID SURFACES UNDER HIGH STRESS EVEN WHEN THE AMBIENT TEMPERATURE EXTERNAL TO SAID TANK DROPS BY AS MUCH AS 50 DEGREES F. IN ONE HOUR.