Flange sealing structure for heat exchanger and liquid treatment equipment

The flange sealing structure comprises a flange plate and a sealing gasket, the flange plate is used for being fixed to the heat exchanger, the flange plate is provided with a liquid inlet cavity, the liquid inlet cavity is used for being communicated with the heat exchanger and inputting heat exchange media into the heat exchanger, and the flange plate is further provided with at least one first limiting part. The first limiting part is located on the side, facing the heat exchanger, of the flange plate, the sealing gasket is used for being arranged between the flange plate and the heat exchanger, the sealing gasket is provided with a first through hole matched with the liquid inlet cavity so that the liquid inlet cavity can be communicated with the heat exchanger, the sealing gasket is provided with at least one second limiting part, and the second limiting parts are arranged on the side, facing the flange plate, of the sealing gasket. And the second limiting parts and the first limiting parts are in one-to