The manufacturing method of nitrogen generator with oxygen enriched back flow expansion

      The distillation tower includes a turbine expander, a main heat exchanger and a subcooler for heat exchange, a distillation tower and a condensing evaporator. The distillation tower includes an upper tower and a lower tower. The outlet of the purification system is connected to the air inlet of the lower tower through a pipeline which passes through the main heat exchanger.

      The lower tower is also provided with an oxygen enriched liquid air outlet for the air outflow of the oxygen enriched liquid produced by distillation, the oxygen enriched liquid air outlet is connected to the purification system through a pipeline, and the pipeline passes through the main heat exchanger; the upper tower is provided with a nitrogen outlet, and the pipeline connected to the outlet passes through the main heat exchanger.