Vacuum sewage collection systems
Economical and clean sewage collection system using negative pressure
Product Lineup
In Japan, the profitability of sewerage projects is expected to be a major issue in the future, since many regions continue to experience a gradual decline in population due to aging and regional depopulation.
In many rural municipalities, the low residential density, topographical and geological conditions, and surrounding construction environments are factors that make the cost of pipeline construction using natural flow pipelines relatively high. The vacuum type demonstrates its true value as a sewage collection system in the locations with these types of difficulty.
The vacuum sewage collection system collects and transports sewage by mixing it with air through the differential pressure between the vacuum generated in the pipeline and the atmosphere. The system consists of three components: a vacuum valve unit, vacuum pipeline, and vacuum station. Sewage drained from homes and other buildings flows into the vacuum valve unit through the on-premises drainage system using natural flow pipelines. When a certain amount of sewage flows into it, the vacuum valve automatically activates to suck sewage and air into the vacuum pipeline. The air sucked in the vacuum pipeline expands and the sewage becomes a gas-liquid mixed-phase flow that is collected and transported to the vacuum station.
Features
1. Economical
(1) Shallow burial depth
Vacuum pipelines are laid in a “sawtooth” longitudinal layout to enable a shallow burial depth.
(2) Small pipe diameter
Sewage is collected and transported using air expansion. Since this has a high transport speed, it allows for smaller pipe diameters.
(3) Avoids buried objects with ease
If pipeline loss is within the allowable range, it is able to avoid buried objects by going over and below them.
2. Leakproof and clean
Since a vacuum is maintained inside the pipeline, sewage will not leak out when there is minor damage. Its high airtightness prevents groundwater and other liquids from infiltrating the pipe. In addition, it does not require cleaning because of the high transport speed of the sewage. This system is less susceptible to scum because floating objects are sucked in when the vacuum valve is operated.
3. Earthquake resistant
Electric power is required only for the vacuum station to collect and transport sewage. Therefore, it facilitates power outage countermeasures. In addition to its strength, chemical resistance, and corrosion resistance, it can also use polyethylene pipes with excellent earthquake resistance as the pipe material for vacuum pipelines.