A liquefier device for producing liquid oxygen and liquid nitrogen comprising:
- a plurality of heat exchangers including an oxygen cooler, a nitrogen bath boiler, a preheater for heating a vaporized nitrogen flow produced by the boiler, a condenser, and an added cooling heat exchanger;
- the oxygen cooler, boiler, and condenser connected for cooling an oxygen gas flow from an oxygen gas inlet line prior to the oxygen gas flow entering an oxygen production flash pot for converting the oxygen gas flow to subcooled liquid oxygen;
- a turbine assembly including a plurality of turbine expanders connected in parallel and exiting to a common header, and a plurality of turbine boosters connected in series each having an associated aftercooler;
- the turbine boosters connected in series connected to pass a major flow of compressed nitrogen gas into a last of the turbine boosters connected in series, and an exit line of the aftercooler associated with the last turbine booster connected in series connected for the major flow to provide warming nitrogen flows via branch lines to the oxygen cooler and to the preheater, and to a bypass valve, said branch lines rejoining prior to directing the rejoined major flow sequentially into the boiler, and then into the condenser where the rejoined major flow is converted to a two-phase liquid gas nitrogen stream;
- the added cooling heat exchanger further cooling the two-phase liquid gas nitrogen stream prior to entering a nitrogen pump flash pot wherein the two-phase liquid gas nitrogen stream is converted to a single-phase liquid nitrogen flow;
- a liquid nitrogen pump connected for moving a branch flow of the single-phase liquid nitrogen flow produced by the nitrogen pump flash pot to a higher pressure prior to entering a shell side of the nitrogen bath boiler, wherein said branch flow of the single-phase liquid nitrogen flow is vaporized, forming a vaporized nitrogen flow;
- the preheater connected to warm the vaporized nitrogen flow exiting the boiler prior to entering the turbine expanders, wherein the warmed vaporized nitrogen flow is used to drive the turbine expanders, and upon exiting the turbine expanders yielding an expanded nitrogen gas flow having a reduced pressure and a reduced temperature almost at a boiling point of the expanded nitrogen gas flow;
- a turbine exhaust phase separator connected for separating the expanded nitrogen gas flow into nitrogen liquid droplets and a separated nitrogen gas flow, said separated nitrogen gas flow connected to remove heat from the condenser, boiler, and oxygen cooler, and to remove the latent heat of vaporization from the rejoined major flow in the condenser;
- the nitrogen liquid droplets fed through a liquid line to a shell side of the oxygen production flash pot, a shell side of the nitrogen pump flash pot, and a shell side of the nitrogen production flash pot;
- and
- separate exit nitrogen gas lines connecting from the shell side of the nitrogen production flash pot and the shell side of the nitrogen pump flash pot providing cooling flows of exit nitrogen gas to the added cooling heat exchanger and condenser, another liquid line containing flashed liquid nitrogen droplets connecting from the turbine exhaust phase separator to the exit nitrogen gas line from the nitrogen production flash pot prior to entering the condenser, and a separate exit nitrogen gas line connecting from the shell side of the oxygen production flash pot providing another cooling flow of exit nitrogen gas to the condenser, said separate exit nitrogen gas lines joining in a connected exit nitrogen gas line and providing a combined cooling flow of nitrogen gas to the boiler and the oxygen cooler, said connected exit nitrogen gas line then joining a low pressure nitrogen gas inlet line connecting to an inlet to the first turbine booster connected in series.