Pure water nitrogen sealing device

The utility model relates to a pure water treatment system, and discloses a pure water nitrogen sealing device which comprises a nitrogen sealing water tank (1) and a nitrogen water sealing device, the nitrogen sealing water tank (1) is provided with a water inlet (11), a water outlet (12) and a nitrogen supplementing pipeline (13), and the nitrogen water sealing device comprises a water sealing barrel (3) and a water sealing structure (14). The nitrogen seal water tank (1) is respectively connected with the water seal barrel (3) and the water seal structure (14) through a three-way pipe (16), the connecting end of the three-way pipe (16) and the water seal barrel (3) extends into the bottom of the water seal barrel (3), and the water seal structure (14) comprises a bent pipe section and a straight pipe II (8) which are connected in sequence. According to the pure water nitrogen sealing device, nitrogen in the nitrogen sealing water tank is repeatedly utilized in the ascending and descending processes of the