Complete recycle urea synthesis process

Claim 1

IN A COMPLETE RECYCLE UREA SYNTHESIS PROCESS WHEREIN AMMONIA, CARBON DIOXIDE AND RECYCLED AMMONIUM CARCLAVE, UNCONVERTED AMMONIUM CARBANETE IN THE AUTOCLAVE EFFUENT STREAM IS DECOMPOSED TO GENERATE FIRST AND SECOND OFF-GAS STREAMS AT FIRST AND SECOND SUCCESSIVELY LOWER PRESSURE LEVELS, SAAID OFF-GAS STREAMS CONTAINING AMMONIA, CARBON DIOXIDE AND WATER VAPOR, THE REAIDUAL LIQUID STREAM BAMATE SOLUTION ARE REACTED AT ELEVATED PRESSURE IN AN AUTOCOMORISING AQUEOUES UREA SOLUTION IS HEATED TO REMOVE EXCESS WATER AS GENERATED STEAM, THE FIRST OFF-GAS STREAM IS PASSED TO A FIRST ABSORBER, THE SECOND OFF-GAS STREAM AND SAID GENERATED STEAM ARE PASSED TO A SECOND ABSORBER, SAID ABSORBER SERVING TO PARTIALLY CONDENSE SAID GASEOUS STREAMS BY CONTACT WITH CIRCULATING AQUEOUS AMMONIUM CARBAMATE SOLUTION WHEREBY STREAMS OF PURE AMMONIA GAS ARE WITHDRAW OVERHEAD FROM SAID ABSORBERS AND RECYCLED TO UREA SYNTHESIS, EXCESS CONCENTRATED AQUEOUS AMMONIUM CARBAMATE SOLUTION IS WITHDRAW AS FIRST ABSORBER BOTTOMS AND RECYCLED TO UREA SYNTHESIS, AND EXCESS DILUTE AQUEOUS AMMONIUM CARBAMATE SOLUTION IS WITH DRAW AS SECOND ABSORBER BOTTOMS AND PASSED TO SAID FIRST ABSORBER, A METHOD FOR MAINTAINING CONSTANT STIOCHIOMETRIC UREA PRODUCTION RATE AND PROCESS WATER BALANCE COMPRISING MAINTAINING THE CONCENTRATED AQUEOUS AMMONIUM CARBAMATE SOLUTION IN SAID FIRST ABSORBER AT A CONSTANT LEVEL BY REGULATING THE RATE OF WITHDRAWL OF SECOND ABSORBER BOTTOMS IN RESPONSE TO CHANGE IN SAID LEVEL MAINTINAING THE DILUTE AQUEOUS AMMONIUM CARBAMATE SOLUTION IN SAID SECOND ABSORBER AT A CONSTANT LEVEL BY REGULATING THE RATE OF STEAM GENERATION IN RESPONSE TO CHANGE IN SAID LEVEL, AND MAINTAINING THE CONCENTRATED AQUEOUS AMMONIUM CARBAMATE SOLUTION AT A SUBSTANTIALLY CONSTANT CONCENTRATED BY MODIFYING THE RATE OF RECYCLE OF FIRST ABSORBER BOTTOMS TO UREA SYTHESIS AS A DIRECT FUNCTION OF PROCESS VARIATION IN BOTTOMS SOLUTION CONCENTRATION.