VACUUM PRESSURE RECOVERY DEVICE, VACUUM TYPE SEWERAGE SYSTEM, AND VACUUM PRESSURE RECOVERY METHOD

PROBLEM TO BE SOLVED: To recover the pressure in a vacuum conduit of a vacuum type sewerage system.SOLUTION: A vacuum pressure recovery device includes: an atmospheric opening valve in which, when a pressure equal to or less than a first pressure is provided, a first valve body moves and opens an air circulation path introducing air into a vacuum conduit, the provided pressure rises to a prescribed pressure, thereby the moved first valve body returns and the air circulation path is closed; a vacuum pressure circulation flow channel connected to the vacuum conduit and the atmospheric opening valve, and providing the prescribed pressure obtained on the basis of a pressure in the vacuum conduit to the atmospheric opening valve; a mechanical controller configured so that, when the pressure in the vacuum conduit rises to a pressure equal to or more than a second pressure, a second valve body moves by utilizing an increase in pressure and opens the air circulation path; and an atmospheric air introduction section installed on halfway of the vacuum pressure circulation flow channel and communicating with the atmosphere, gradually introducing air into the vacuum pressure circulation flow channel, and gradually increasing the prescribed pressure provided to the atmospheric opening valve.