| 摘要 |
<p>A vacuum sewer arrangement comprises a bowl (1) connected to a sewer pipe (2) provided with means for establishing, in the sewer pipe (2), a vacuum sufficient for obtaining efficient sewage transport. There is a normally-closed sewer valve (3) connecting the bowl (1) to the sewer pipe (2) and a control device (7) for controlling operation of the sewer valve (3) to allow discharge of sewage from the bowl (1) to the sewer pipe (2). There is also an air inlet duct (4) for letting air into the sewer pipe (2) separately from the bowl (1). For controlling flow of air through the air inlet duct (4) into the sewer pipe (2), when the sewer pipe (2) is under proper vacuum for effective sewage transport, there is an air inlet valve (6) with means operating it in response to pressure variations in the sewer pipe (2). Such pressure variations occur when the sewage discharged from the bowl (1) has passed the point (36) where the air inlet duct (4) is connected to the sewer pipe (2). This ensures that the air inlet valve (6) operates accurately and securely. <IMAGE></p> |
