Device for preparing urea

Claim 1

AN APPARATUS FOR SYNTHESIZING UREA FROM AMMONIA AND CARBON DIOXIDE BY THE INTERMEDIATE FORMATION OF AMMONIUM CARBAMATE, COMPRISING A SYNTHESIS AUTOCLAVE, COMPRISING AN AMMONIUM CARBAMATE REACTOR PORTION AND A UREA REACTION PORTION SEPARATED BY A WALL, PROVIDED WITH A SUPPLY CONDUIT FOR THE REACTION MIXTURE AND AT LEAST ONE SERIES OF HEAT EXCHANGER BUNDLES IN THE AMMONIUM CARBAMATE REACTOR PORTION, EACH HEAT EXCHANGER BUNDLE COMPRISING ELEMENTS CONSISTING OF CONCENTRIC INNER AND OUTER PIPES, THE OUTER PIPE SEALED AT THE END WITHIN THE AMMONIUM CABAMATE REACTOR PORTION AND THE INNER PIPE PASAGEWAY IN CONNECTION WITH AN ANNULAR SPACE BETWEEN THE INNER PIPE AND THE OUTER PIPE NEAR THE SEALED END OF THE OUTER PIPE, OVERFLOW OPENINGS IN THE WALL OF THE AMMONIUM CARBAMATE REACTOR PORTION ALLOWING PASSAGE INTO THE UREA REACTION PORTION, A STRIPPING COLUMN COMMUNICATING WITH THE UREA REACTION PORTION OF THE SYNTHESIS AUTOCLAVE A CONDUIT FOR THE SUPPLY OF STRIPPING GAS AND A DISCHARGE CONDUIT FOR THE GAS RELEASED IN THE STRIPPING COLUMN COMMUNICATING WITH THE AMMONIUM CARBAMATE REACTOR PORTION ATTACHED TO TH STRIPPING COLUMN, A RECTIFYING COLUMN AND A GAS-LIQUID SEPARATOR, A CONDUIT, PROVIDED WITH A THROTTLE VALVE, CONNECTING THE STRIPPING COLUMN AND THE RECTIFYING COLUMN, THE RECTIFYING COLUMN COMMUNICATING WITH THE GAS-LIQUID SEPARATOR, A CONDUIT CONNECTING THE RECTIFYING COLUMN TO A SERIES OF INNER PIPES IN THE HEAT EXCHANGER IN THE CARBAMATE REACTOR, A CONDUIT FROM THE ANNULAR SPACE BETWEEN THE INNER AND OUTER PIPES OF THE HEAT EXCHANGER TO THE GAS-LIQUID SEPARATOR, AND A DISCHARGE CONDUIT FITTED TO THE BOTTOM OF THE GAS-LIQUID SEPARATOR.

Claim 2

AN APPARATUS FOR SYNTHESIZING UREA FROM AMMONIA AND CARBON DIOXIDE BY THE INTERMEDIATE FORMATION OF AMMONIUM CARBAMATE, COMPRISING A SYNTHESIS AUTOCLAVE, COMPRISING AN AMMONIUM CARBAMATE REACTOR PORTION AND A UREA REACTION PORTION SEPARATED BY A WALL, PROVIDED WITH A SUPPLY CONDUIT FOR THE REACTION MIXTURE AND AT LEAST ONE SERIES OF HEAT EXCHANGER BUNDLES IN THE AMMONIUM CARBAMATE REACTOR PORTION, EACH HEAT EXCHANGER BUNDLE COMPRISING ELEMENTS CONSISTING OF CONCENTRIC INNER AND OUTER PIPES, THE OUTER PIPE SEALED AT THE END WITHIN THE AMMONIUM CABAMATE REACTOR PORTION AND THE INNER PIPE PASAGEWAY IN CONNECTION WITH AN ANNULAR SPACE BETWEEN THE INNER PIPE AND THE OUTER PIPE NEAR THE SEALED END OF THE OUTER PIPE, OVERFLOW OPENINGS IN THE WALL OF THE AMMONIUM CARBAMATE REACTOR PORTION ALLOWING PASSAGE INTO THE UREA REACTION PORTION, A STRIPPING COLUMN COMMUNICATING WITH THE UREA REACTION PORTION OF THE SYNTHESIS AUTOCLAVE A CONDUIT FOR THE SUPPLY OF STRIPPING GAS AND A DISCHARGE CONDUIT FOR THE GAS RELEASED IN THE STRIPPING COLUMN COMMUNICATING WITH THE AMMONIUM CARBAMATE REACTOR PORTION ATTACHED TO TH STRIPPING COLUMN, A RECTIFYING COLUMN AND A GAS-LIQUID SEPARATOR, A CONDUIT, PROVIDED WITH A THROTTLE VALVE, CONNECTING THE STRIPPING COLUMN AND THE RECTIFYING COLUMN, THE RECTIFYING COLUMN COMMUNICATING WITH THE GAS-LIQUID SEPARATOR, A CONDUIT CONNECTING THE RECTIFYING COLUMN TO A SERIES OF INNER PIPES IN THE HEAT EXCHANGER IN THE CARBAMATE REACTOR, A CONDUIT FROM THE ANNULAR SPACE BETWEEN THE INNER AND OUTER PIPES OF THE HEAT EXCHANGER TO THE GAS-LIQUID SEPARATOR, AND A DISCHARGE CONDUIT FITTED TO THE BOTTOM OF THE GAS-LIQUID SEPARATOR.