Interrupted thread type supercritical fluid foaming sealing in-situ opening and closing device

The invention provides a discontinuous thread type supercritical fluid foaming sealing in-situ opening and closing device aiming at the defect that the installation and operation space of a manhole sealing end of supercritical fluid foaming horizontal tank equipment is large. Rapid opening and closing of the foaming device are achieved through two-step type intermittent threaded connection, three-layer step type structure matching and in-situ rotation, and the intermittent threaded kettle cover is matched with the in-situ ring body and the opening and closing end of the kettle body to achieve rotary transferring of the kettle cover and sealing of the kettle body through insertion and screwing of the grooved intermittent threads; the in-situ ring body and the discontinuous thread kettle cover form a double-layer cover body structure, so that rotation around the side surface of the kettle body is realized, and meanwhile, the in-situ ring body is easily fixed and locked in a three-layer step type structure at th