High yield high purifying nitrogen apparatus

The utility model provides a high yield high purifying nitrogen apparatus, which comprises a preprocessing system, a purifying system and a fractionating tower, the preprocessing system comprises filters, air compressors and pre-cooling machines which are connected in turn; the fractionating tower comprises a turbine expansion machine, a rectification tower and a condensation evaporator, the rectification tower comprises an upper tower and a lower tower, an outlet of the purifying system is connected to an air inlet of the lower tower by a pipeline, the pipeline passes through a main heat exchanger; the lower tower is also provided with an oxygen-enriched solution air outlet, the preprocessing system comprises two sets of filters, air compressors and the pre-cooling machines which are connected in parallel in turn. According to the utility model, the oxygen-enriched pipeline, a raw material air pipeline and a nitrogen gas pipeline are simultaneously connected to the main heat exchanger to enable the cooling c