Vacuum Sewer Systems
RoeVac® Vacuum Sewer Systems
High groundwater table, low population density, flat terrain (lack of natural slope); unfavourable soil conditions like sandy, unstable or rocky ground are the ideal circumstances to use RoeVac® vacuum sewer systems. In areas along rivers, lakes or coasts as well as in water protection zones, vacuum sewer systems are often the only choice. Moreover they offer specific advantages for residential areas where wastewater flow is low or vary in a wide range (e.g. tourist areas). Other benefits include independence from terrain, small pipe diameters, high flexibility and low maintenance costs.
The advantages are also evident in the construction phase: small pipe diameters allow narrow trenches and reduced excavation works. This allows streets and footpaths to be used during construction works. A benefit which especially the residents in the immediate vicinity and all road users highly appreciate. In addition, vacuum sewers and fresh water lines may be laid in the same trench according to the German guidelines.
Wastewater from a vacuum sewer pipe network is collected in a central vacuum station via differential air pressure. From there, the wastewater is forwarded to a wastewater treatment facility or to other sewer collection systems (central force main, gravity sewer, etc.). The vacuum station typically includes one or two vacuum vessels, several vacuum pumps, two non-clog sewage pumps, and a control panel. The pipeline system is maintained under vacuum at all times by the vacuum pumps.
A pipeline network connects the vacuum station with collection chambers that are typically installed adjacent to the private houses. The collection chambers equipped with vacuum valve units are the transition between the conventional gravity lines from the houses and the vacuum system. Wastewater flows by gravity from a house into a collection chamber’s sump. After a given quantity (batch) of wastewater accumulates in the sump, a vacuum valve automatically opens. The vacuum valve uses differential air pressure (atmosphere & vacuum) as its energy source. No electrical power is required at the collection chambers. After approximately 5 seconds the valve closes and the process can start again.
|
