The invention provides high-purity
nitrogen equipment which comprises a preprocessing
system, a purifying
system and a fractionating
tower, wherein the fractionating
tower comprises a
turboexpander, a main
heat exchanger and a subcooler for heat exchange, a rectifying
tower and a condensation
evaporator, the rectifying tower comprises an upper tower and a lower tower, the outlet of the purifying
system is connected with the air inlet of the lower tower through a pipeline, and the pipeline passes through the main
heat exchanger; the lower tower is also provided with an
oxygen-enriched
liquid air outlet for
oxygen-enriched
liquid air generated by rectification to flow out, the
oxygen-enriched
liquid air outlet is connected with the purifying system through a pipeline, and the pipeline passes through the main
heat exchanger; and the upper tower is provided with a
nitrogen gas outlet, and the pipeline connected with the outlet passes through the main heat exchanger. In the invention, the pipeline of enriched oxygen, the pipeline of
raw material air and the pipeline of
nitrogen gas are simultaneously connected with the main heat exchanger, so that the cold quantities of the enriched oxygen and the
nitrogen gas are fully utilized, and the high-purity nitrogen equipment saves the energy and protects the environment; meanwhile, the enriched oxygen is sent into the expander for
refrigeration, and the high-purity nitrogen equipment has the advantages of reasonable structure, material saving and simple flow configuration.