Emergency acid return device for pickling

The utility model discloses an emergency acid return device for pickling, which comprises a total acid tank, a main acid pipe, a ceramic filter and an acid inlet structure for inputting acid liquor into the ceramic filter, the total acid tank is connected with a middle barrel through an acid feeding pipe, an acid feeding pump is mounted on the acid feeding pipe, and one end of the main acid pipe is connected to the total acid tank; the middle barrel is fixedly connected with an acid outlet pipe; the acid outlet pipe is connected with the main acid pipe and is provided with an acid outlet valve for controlling the opening and closing of acid liquor; the acid inlet structure comprises an acid inlet pipe connected to the main acid pipe, an acid preparation barrel communicated with the acid inlet pipe and an acid pickling pipe connected between the ceramic filter and the acid preparation barrel, an acid inlet valve used for controlling the on/off of acid liquor is mounted on the acid inlet pipe, and a metering pu