| 摘要 |
<p>The present invention relates to an unpowered apparatus for preventing backflow, comprising: a tubular main body having a stepped portion, wherein the main body has an inlet port for the inflow of sewage, an outlet port for discharging the sewage, and a communication port which is inclined toward the outlet port and which puts the inlet port and the outlet port in communication; an opening/shutting door having a door body rotatably hinged to the inside of the main body so as to open/shut the communication port, and a pair of blocking plates extending from either side of the door body so as to block the space between the stepped portion and an inner wall of the main body; a floating part which is arranged in the opening/shutting door, the interior of which is empty such that the floating part can float on a water surface, and which provides the opening/shutting door with buoyancy and operates the opening/shutting door so as to close the communication port when the sewage flows back toward the outlet port; and a guide interposed between the stepped portion and a bottom surface of the main body so as to guide the sewage introduced from the inlet port such that the sewage flows toward the outlet port via the communication port.</p> |
