Transformers with evaporative cooling system

Claim 1

IN A POWER TRANSFORMER HAVING AN EVAPORATIVE LIQUID COOLING SYSTEM OPERATING WITHIN A PRESSURE-RESISTANT CASING INCLUDING A SUMP FOR A LIQUID COOLANT, SPARY MEANS TO SPRAY LIQUID COOLANT WITHIN SAID CASING, A PUMP TO SUPPLY THE SPRAY MEANS FROM SAID SUMP, A COOLANT MIXTURE OF FIRST AND SECOND FLUIDS, THE FIRST FLUID HAVING A BOILING POINT LESS THAN THE OPERATING TEMPERATURE OF THE TRANSFORMER UNDER FULL LOAD AND THE SECOND LIQUID HAVING A LOWER BOILING POINT AND COLLANT MIXTURE SEPARATION MEANS CONNECTED TO SAID CASING, THE IMPROVEMENT WHICH COMPRISES IN FRACTIONATING COLUMN, TUBULAR MEANS CONNETING SAID COLUMN TO SAID CASING, CONDENSER MEANS CONNECTED TO SAID COLUMN, A REFRIGERATED CONDENSER ELEMENT WITHIN SAID CONDENSER MEANS, A RECEIVER CONNECTED TO SAID CONDENSER MEANS TO RECEIVE A STORE LIQUID DISCHARGED BY SAID CONDENSER ELEMENT, A MASTER VALVE CONTROLLING FLOW OF FLUID THROUGH SAID TUBULAR MEANS, SAID VALVE BEING CONSTRUCTED TO OPEN IN RESPONSE TO A RISE IN PRESSURE IN THE CASING ABOVE A PREDETERMINED VALVE AND TO CLOSE IN RESPONSE TO A PRESSURE IN SAID CASING CORRESPONDING TO THE SUBSTANTIALLY COMPLETE REMOVAL FROM THE CASING OF SAID SECOND FLUID, A FLUID FROM LINE CONNECTING SAID CONDENSER MEANS TO SAID CASING AND A ONE-WAY CHECK VALVE TO PERMIT FLOW THROUGH SAID LINE ONLY WHEN PRESSURE IN SAID CASING IS LESS THAN THE PRESSURE IN SAID CONDENSER MEANS.