Content. 1 Basics. 2 Detailed Information on different types of Vacuum technologies. Vacuum sanitary installations. Vacuum sewer systems

Transcription

1 Vacuum Technology - collection and transport of sewage by means of low pressure Christine Werner, Florian Klingel, Ulrike Mosel, Sebastian Hass Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH ecological sanitation programme, Division 44 environment and infrastructure Commissioned by: ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

2 Content 1 Basics 2 Detailed Information on different types of Vacuum technologies Vacuum sewer systems Vacuum sanitary installations How it works Application Operation and maintenance Economical data Evaluation ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

3 Basics and main benefit for ecosan Sewage collection tool (ships, train, aircrafts) Domestic technology: Vacuum sewer and Vacuum sanitary installations Wastewater transport by using air instead of water Integrated ecological concepts can be realized Flushing water amount is reduced to 80%, unnecessary dilution of flow streams is avoided, high concentrations of recyclables Split stream collection Greywater: Blackwater: irrigation or ground infiltration anaerobic treatment incl. biogas production and power generating, end use of the bio sludge products as a valuable fertilizer ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

4 Vacuum sewer systems - How it works Vacuum sewer line Collection chambers Vacuum station Vacuum Sewerage consists of 3 main components: Central vacuum station which creates low pressure Vacuum sewer line for transport of sewage Collection chambers with interface units ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

5 How it works Wastewater flows by gravity into the collection chamber; from there the waste water is evacuated into the system No modifications inside the house! ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

6 How it works Wastewater flows by gravity into a collection sump. When a certain quantity of liquid has accumulated, air in the sensor pipe is compressed and the controller unit gives a signal to the interface valve. The waste water is then sucked by the valve into the vacuum connection sewer. Air sucked in afterwards creates the necessary pressure gradient. The air quantity streaming in afterwards, pushes away all liquids out from the sump. Approximately four seconds after, the interface valve will close again. ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

7 How it works ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

8 How it works Passing procedure Saw tooth- pocket or wave profile Significant high and low points Wastewater comes to rest at low points and forms plugs ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

9 How it works Wastewater flows to the low point In the low point wastewater is collected, closing the pipe-diameter When air is admitted through an upstream interface valve, plugs are accelerated and pushed over the high points towards the vacuum station ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

10 How it works ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

11 Application Suitability of vacuum sewer system Low density population settlement Decentralized or semi-decentralized sanitation systems Insufficient natural soil conditions (i.e. unstable soil or rock, high groundwater table, complicate excavation) Obstacles to the sewer route Seasonal operation (holiday resorts) Water sensitive areas (lakes, rivers and coasts, or where flooding can occur) ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

12 Operation and maintenance High Technology, requires correct construction, maintenance and damage control Emergency generator in case of frequent power cuts No blockages (turbulent flow), continuous aeration prevents deposits, odours and septicity No flushing of sewer required Maintenance and electrical energy limited to one central station Access can be gained at each collection chamber Troubleshooting: Division valves installed on major branch connections and on the mains to allow for isolation ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

13 Economical data Vacuum sewer systems are 20 to 25 % less costly to construct than conventional sewers due to following cost savings ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

14 Economical data Capital and operational cost savings due to Narrow and shallow trenches Low diameter of sewer Efficient construction period No requirements of manholes No requirements to clean or remove sediments from within the vacuum sewer Elimination of infiltration allows a reduction of size and costs of the treatment plant Pump sizes and subsequently electrical power consumption are significantly reduced concerning no groundwater infiltration ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

15 Vacuum sanitary installations - How it works Air pressure gradients generate rapid airflow Large scale application Small scale application Constant vacuum system Vacuum on demand CVS VOD ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

16 How it works - CVS CVS Vacuum station (vacuum pumps, sewage pumps, vacuum tank and control panel) Vacuum piping (40 to 70 mm) Vacuum toilets and interface units for all kind of fixtures Greywater from showers, washbasins, sinks is collected in pneumatically regulating interface valves, until a certain volume is reached washbasin shower/ bathtub interface unit vacuum collection line to sewer interface unit vent stack vacuum toilet vacuum station vacuum toilet vacuum pumps sewage pumps ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

17 How it works - CVS Vacuum toilets Wall-, floor-, squatting model sanitary porcelain or stainless steel principle: After use of toilet, flushing (0,7-1,2 litre/flush) is triggered by pushing a button. The interface valve is opened when the button is released and the blackwater, together with a volume of 10 to 50 litres air is evacuated through the vacuum lines to the system tank ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

18 How it works - CVS Example for greywater connection Pneumatic sensor Atmospheric pressure Ventilation valve Under pressure Control unit Greywater is collected via gravity in holding tank, up to certain volume Greywater holding tank valve Pneumatic sensor is activated by hydrostatic pressure Control unit opens a pneumatic valve for an adjustable time period Greywater and some air is evacuated through the open valve into the vacuum collection line ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

19 How it works - CVS Interface for wash basin Vacuum station PE vessel Vacuum station steel vessel ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

20 How it works - VOD VOD Vacuum aerator (produces vacuum, macerates sewage, pumps sewage) Vacuum piping (50 mm) Vacuum toilets and interface units Principle: No vacuum in the pipeline unless someone activates flush button Toilets connected to a vacuum arator which in one operation evacuates the wastewater and discharges it to the public gravity sewer or to a kind of storage tank, if further treatment is required ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

21 Application Suitability of Vacuum sanitary installation Water consumption has to be reduced for environmental or costs reasons Sewers or WWTP`s are non existent or overloaded Sanitary facilities are frequently used Insufficient slope, lack of space, low ceilings, or other structural limitations make gravity drainage impossible or difficult Separate grey- and blackwater treatment is required Reconstruction, modernisation or modification of existing structures is difficult or expensive ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

22 Operation and maintenance High Technology, requires correct construction, maintenance and damage control Caretakers need special education CVS: saw-tooth profile, VOD: no specific kind of passing procedure Vacuum toilets used in same way as flush toilets, different flushing noise No blockages (turbulent flow), continuous aeration prevents deposits, odours Troubles: Lime and urine precipitation is possible, effective chemicals against such deposits Power breakdowns cause break downs of VOD, not for CVS ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

23 Economical data Investment costs of Vacuum sanitary systems are 40% higher than for a conventional system due to higher costs for vacuum toilets and vacuum station But amortisation due to high water prices is possible within a couple of years ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

24 Evaluation Strengths Weaknesses Health impact Environmental impact Socio-cultural suitability No leakage Highest hygienic safety (closed system) No pathogen contamination of the groundwater Reduction of wastewater flows through sewers and WWTP`s Tool for integrated ecological concepts such as energy recovery (biogas) from blackwater possible High security against leakage of wastewater Water savings up to 80% for vacuum toilet flushing High Tech provides the same comfort than gravity No odour nuisance Additional energy for operation required Correct construction, operation and maintenance required ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

25 Evaluation Costs and benefits Technical suitability Strengths 20 to 25% than conventional sewerage due to easy construction without heavy machinery Due to water savings amortisation for vacuum sanitary installation within few years possible Ductile lightweight material, ease of installation and handling No slope requirements Shallow and narrow trenches High flexibility according to appearing obstacles Weaknesses Vacuum sewer system require about 10 to 30 KWh/(p*a) Vacuum sanitary installation require about 4 KWh/(p*a) and cause higher investment costs High Tech solution Correct construction, operation and maintenance required Vulnerable for power break downs ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

26 Thanks for your attention QUESTIONS??? ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^

27 VOD vacuum arator ecosan im GTZ Haus 1, ecosan Praktikanten und Baseline Studien Tage, Eschborn, 1^