How can such a simple system work so well?

The system consists of toilets and greywater interfaces connected to a vacuum generator via the piping.

Generating vacuum in the piping

The basic principle behind a vacuum toilet system is to use differences in air pressure to transport sewage from toilets and urinals (sometimes also greywater). In our modern vacuum systems, the Vacuumarator™ pump generates vacuum directly in the piping system. The entire piping system is kept at a constant vacuum level, normally between 35% and 50% (in a Constant Vacuum System - CVS™).

Transporting sewage from toilets

When a toilet is flushed, a valve in the toilet opens. Approximately 60 litres of air along with about 1 litre of water is sucked into the piping system because of the vacuum present in the piping. The water and sewage create a "slug", which is transported through the piping system because of the different air pressure levels in front of and behind the slug.

Re-forming slugs

During the transport through the vacuum piping, the slug is affected by gravity and flattens out after a time. Slugs have to be re-formed in the piping. This is done by installing low points in the piping, known as transport pockets. As blackwater builds up in the transport pockets, new slugs are formed. At the next flush of a toilet, the slug moves on and re-forms again and again in transport pockets further down the piping system.

Simple yet advanced pump

Vacuum is generated by one or more Vacuumarator™ pumps. Black water is macerated and pumped to a sewage treatment plant or a collecting tank.

 

Sewage transport in a vacuum piping system