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(Image: Protective hose guide - on the vehicle) During cleaning procedures in sewer systems, high-pressure flushing hoses are exposed to mechanical stress due to internal pressure, as well as tensile, bending and frictional forces. In practice, guide rollers or hose guides are used to reduce these stresses. They help guide the flushing hose and the nozzle to a horizontal position in the sewer without kinks, therefore avoiding hose contact at the edges … |
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Further measures to increase the service life of high-pressure flushing hoses include:
(Image: Example of damages to the outer cover of a high pressure flushing hose) (Image: Example of damages to the outer cover of a high pressure flushing hose) (Image: Example of damages to … |
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Operational errors in the use of high-pressure hoses:
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Suction tubes are used to extract the waste material collected in the manhole. (Image: Suction tube in manhole) (Image: Suction tube with damming flaps) Images: Extraction of the waste material from a manhole using a suction tube [Image: Prof. Dr. Ing. Stein & Partner GmbH] |
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In practice, abrasion-proof rubber tubes are used for this purpose. They have to meet the following requirements
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According to [DIN30705:1991], the nominal size of the suction tube needs to correspond hydraulically to the volumetric flow rate of the vacuum pump. (Table: Recommended nominal sizes of the suction tube in reference to the volumetric flow rate of the vacuum pump) |
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Sep 27, 2012 (Video: High pressure water jetting with a combined vehicle with water treatment technique) Animation: Combined high pressure flushing and suction vehicle with water treatment technology [Image: visaplan GmbH]. This object is only visible in the online version of the module. |
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May 27, 2013 Congratulations! You have successfully finished this module. Next you will have the opportunity to review the newly acquired knowledge with an interactive questionnaire. You can of course still navigate back to any point in the modules if you wish to review a specific point or subject. Stay curious! |
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May 09, 2012 Depending on the boundary conditions, different types of vehicles are used for high-pressure cleaning. This module provides a detailed overview of the cleaning vehicles and familiarises you with the central process sequences and the diverse vehicle technology. After completing this module, you will have a sound knowledge of:
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Wastewater according to [[DIN EN 752]] Water composed of any combination of water discharged from domestic, industrial, and commercial sources; surface runoff; and accidental any sewer infiltration water. Wastewater is a term typically used to describe liquid wastes from two types of sources. The first source, sanitary sewage, is generated from homes, businesses, institutions and industries. The second source, stormwater, is generated from rain or … |
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(Image: Domestic wastewater)
(Image: Industrial (commercial) waste water)
(Image: Infiltration of extraneous water)
(Image: Storm water)
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According to the municipal sewage regulations, substances that could adversely affect the stability of the public sewers should not enter into the system. Limiting regulations exist under [DWAM115-2:2013] for
Generally, municipalities and water utilities have by-laws specifying limitations on wastewater discharge. |
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The various components found in wastewater are classified according to their physical state:
(Image: Emulsion example) |
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Undissolved substances are referred to as solid or particulate substances or matter. According to [DIN38409:1987] they are divided into suspended and settleable solids.
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Solids are categorised by their composition into:
(Image: Organic solids in sewer line) (Image: Mineral solids in the sewer line) (Image: Deposits in the sewer – sewer film) (Video: Organic and mineral deposits in the sewer line) Video: Organic and mineral deposits in the sewer line [Prof. Dr. Ing. Stein & Partner … |
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The solids found in sewers originate predominantly from the following sources:
(Image: Origin of solids) |
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Domestic wastewater originates from private households and similar facilities. These solids consist of 80-90% organic matter, such as food particles, grease, feces, hair, paper, etc. The remaining portion consists of mineral solids that result from the incorrect disposal of household waste such as cat litter. (Image: Private household drainage system) |
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The entry of solids through stormwater runoff is characterised by the type and location of the drainage system, and is separated into solids entry from roof drainage systems, that are directly connected to the sewer line, and the solids entry from road surfaces through catch basins. The entry of solids through the manhole covers ventilation slots also needs to be taken into consideration. (Image: Roof drainage) (Image: Storm drain - catch basin) (Image: … |
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The stormwater runoff from unsealed and sealed surfaces (i.e. open space, tree grates, yards, parks, roads, etc.), which enters the separate or combined sewer systems through catch basins contains the highest amount of solids. Nearly half of all combined sewer, and 100% of all storm sewer solids come from this source [Artie1988]. (Image: Origin and type of solids from the surface runoff) |
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The type and amount of solids in the storm water runoff from sealed and unsealed surfaces varies from location to location and is influenced by:
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