Closed feeding device with filtering function

The utility model discloses a closed feeding device with a filtering function, which relates to the technical field of feeding devices, solves the technical problems that air enters a liquid preparation tank through the feeding device during feeding and feed liquid in the liquid preparation tank is polluted when the air is not filtered, and comprises a feeding tank and a filtering device, a first vacuumizing connector connected with the vacuumizing system and a first nitrogen connector connected with the nitrogen system are arranged above the feeding tank, the filtering device is arranged at a discharging port of the feeding tank, a discharging valve is arranged at an outlet of the filtering device, and the outlet of the filtering device is connected with the batching tank; according to the utility model, gas in the closed feeding tank is completely replaced by nitrogen, air is prevented from entering the next step along with feeding, impurities in liquid or insoluble substances/reaction derivatives in a solu