Large-diameter nanofiltration membrane shell

The utility model discloses a large-diameter nanofiltration membrane shell which comprises a shell body, the bottom end of the shell body is fixedly communicated with a lower sealing head, a membrane shell flange is fixedly arranged on the periphery of the top end of the shell body, an upper sealing head is arranged at the top end of the membrane shell flange, and a lower positioning plate is fixedly arranged on the inner side of the joint of the shell body and the lower sealing head. According to the large-diameter nanofiltration membrane shell disclosed by the utility model, all membrane elements in the membrane shell are arranged in parallel and continuously enter the same water quality, and the running flux and the pollution condition of the membrane elements in the same membrane shell are relatively balanced, so that the membrane cleaning is more targeted, and the cleaning effect can be effectively enhanced; all the membrane elements are exposed in the same water quality, the service life of the membrane