Method and apparatus for the purification of heavy-water

Claim 1

A METHOD OF PRODUCING HEAVY WATER CONCENTRATE COMPRISING FEEDING FEED WATER TO THE FIRST OF A SERIES OF AT LEAST THREE RECTIFYING COLUMNS, EACH RECTIFYING COLUMN HAVING A PLURALITY OF SPACED TUBES FILLED WITH TOWER PACKINGS THROUGH WHICH DOWNFLOW WATER FLOWS, SAID WATER BEING HEATED FROM OUTSIDE OF THE TUBES WHERE COMPRESSED HEATING MEDIUM FLOWS, FEEDING THE DOWNFLOW WATER IN TURN THROUGH SUCCEEDING COLUMNS, TAKING STEAM OUT OF THE TOP OF EACH OF THE COLUMNS AND FEEDING IT TO THE BOTTOM OF THE RESPECTIVE PRECEDING COLUMNS INTO DIRECT CONTACT WITH THE DOWNFLOW WATER, RECOVERING THE HEAVY WATER CONCENTRATE COMING OUT OF THE LAST COLUMN, RETURNING A PART DENSATES OF HEATING MEDIUM FROM EACH COLUMN WHICH CONDENSE WHILE HEATING EACH COLUMN, RETURNING A PART THEREOF TO THE FIRST COLUMN AND FEEDING IT AS REFLUX WATER INTO DIRECT CONTACT WITH THE STEAM RISING IN THE COLUMN PASSING THE REST THROUGH A HEAT EXCHANGER TO HEAT THE FEED WATER BEING FED TO THE FIRST COLUMN, AND SUPPLYING THE STEAM GENERATED IN THE COLUMNS FROM SAID FIRST COLUMN TO THE SPACE BETWEEN SAID SPACED TUBES AND INTO INDIRECT HEAT EXCHANGE RELATIONSHIP WITH THE DOWNFLOW WATER IN EACH OF SAID COLUMNS AS HEATING MEDIUM,THE PORTION OF SAID STREAM ENTERING EACH COLUMS BEING COMPRESSED BEFORE IT ENTERS EACH COLUMN A NUMBER OF TIMES EQUAL TO THE NUMBER OF THE POSITION OF THE COLUMN IN SAID SERIES OF COLUMNS SO THAT IT ABSORBS ENERGY NECESSARY AND SUFFICIENT FOR CIRCULATION AND HEATING THE COLUMNS.