Pipe connection structure and vacuum-type sewage collecting apparatus

Abstract

A vacuum-type sewage collecting apparatus collect sewage discharged from a plurality of houses or facilities in an accumulating tank through a vacuum sewage pipe network, the inner pressure of which is negative. The vacuum sewage pipe network includes a plurality of upper stream pipes and lower stream pipes fastened to each other in a branch-like fashion. Each lower stream pipe has a sawtooth-like shape formed by alternately disposed downwardly-sloping portions extending gently downwards toward said accumulating tank, and lift portions fastened to the lowermost portion of a respective downwardly-sloping portion and extending upwardly with a steep slope. The upper stream pipe is connected to the lower stream pipe in a range in which a horizontal plane, which extends through an upper end portion of the lower stream pipe at the position in which the downwardly-sloping portion adjoins the lift portion, is higher than the center of the lower stream pipe. The upper stream pipe opens to the lower stream pipe at a position diagonally above the center of the lower stream pipe as viewed in a plane perpendicular to the pipe central axis. At least a portion of the opening is higher than the horizontal plane, and the upper stream pipe extends from the lower stream pipe diagonally upwards.