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Feb 16, 2011 (Image: Pipe saw robot [FI-KMG]) Cutting apparatus are used in the nominal size range from DN 100 to DN 600 for the removal of internally projecting laterals and other localised obstacles as well as roots. They are usually used with the aid of TV observation [NASSCO89a] [WPCF85]. As regards the method of operation, this can be divided into the mechanically operated apparatus and those that work with high pressure water jets. The mechanically operated … |
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Feb 16, 2011 Sand blasting apparatus can be used in order to obtain a particularly high degree of cleaning, especially for creating a metallic white surface on steel and cast piping. The apparatus is pulled into the pipe to be cleaned by means of a tension ring and slowly pulled back with the hose during the sandblasting process, during which the used sand is blown forward to the pipe. This apparatus is supplied for nominal size range DN 60 to DN 1600 (Bild 3.2.4.3.5) |
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Nov 04, 2004 Special apparatus have been developed in the past few years, especially in the non-man-accessible regions, for removal of hardened deposits, internally projecting laterals or artificial obstacles and roots, as well as for achieving a specially high degree of cleanliness. They can be divided according to their method of operation into:
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The process for increasing the flow velocity by the introduction of air is used, for example, in Hamburg in pressure piping. Two or four times a day, or at irregular periods of long-term flushing, air is blown into the pressure pipe system and in this way the flow cross section is reduced. The increased velocity of the flow causes any gathered deposits to be whirled up and conveyed further. In pressure piping that is adapted to the lie of the land, … |
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A further possibility for removing deposits in piping systems is offered by the Ultrasonic process. This process, developed and patented in France, can be used in the nominal size range from DN 20 to DN 600 for drains and sewers as well as for hot water systems [FI-Alben] [Loese98a] [Loese98b]. The manufacturer claims that with a working pressure of 700 to 1050 bar and a water flow of 12 to 17 l/min, pipes of PVC, PE, fibre cement, cast iron, steel … |
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(Image: Vibration nozzle Rümax [FI-IBG]) The cleaning effect of the vibration nozzle is based on the creation of a frequency field, which separates the structure of the deposits to be removed from the pipe or sewer wall and conveyes it away with the wastewater (Bild 3.2.4.4.3). According to the manufacturer, the process can be used for the removal of mineral deposits, concrete, slag, filler masses or similar substances from sewers in the nominal size … |
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These processes are utilised for the removal of
The former case is limited mostly to industrial pipes and pipelines for oil and gas. In the sewage sector it is reserved for exceptional cases. An example of an application of the removal of incrustations in dam wall drainpipes is dealt with in detail in [Siebe81]. Conditions for these applications are especially:
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(Image: Removal of roots by the use of foamed herbicides) The mechanical root removal methods mostly used today, e.g. by cutting or boring (Abschnitt 3.2.4.3) usually leads to strengthened new root formation requiring treatment again at relatively short intervals [Schmi81]. An alternative to this is seen as the treatment with various herbicides, about whose suitability comprehensive experiments have been carried out [Sulli77] [Ahren70] [Townl73]. The … |
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Biological cleaning processes are utilised for the degradation of fats and fibrous materials in the sewer wall slime, as well as phenols, proteins and mineral oils and, furthermore, for removal or reduction of odour nuisances [Baig76] [Jense77]. Fundamentally, there are two possible paths to biological support of the degradation processes of organic oils and fats [ATVAG3116] :
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Nov 04, 2004 In particular cases, special processes are used for cleaning, such as:
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Mechanical cleaning can be carried out
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Nov 13, 2006 Repair of Concrete, Reinforced Concrete and Brick Manholes – Part 2: Climbing Aids, Defects, Joints
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Aug 28, 2019 Cleaning is one of the most important measures for maintaining and ensuring a long-lasting efficiency of drain and sewer systems [ [EN752:2017]]. Cleaning measures can either be implemented proactively or reactively. Proactive cleaning serves to mitigate problems before they occur by implementing the following principal objectives [ [EN14654-1:2005]]:
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Aug 28, 2019 In addition to the principal objectives listed in this chapter, the development of the cleaning plan may include other objectives, as e.g.:
The determination … |
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Aug 28, 2019 A cleaning plan should be based on a demand and condition oriented cleaning strategy, where only sections showing deposits and debris are cleaned. During cleaning, their structural condition is taken into account. This allows for the reduction of the costs incurred during cleaning and the avoidance of excessive stress on the pipes. A demand- and condition-oriented cleaning plan has the objectives to:
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Aug 28, 2019 The starting point for the development of demand- and condition-oriented cleaning plans is a description of the drain and sewer system, the analysis of previous cleaning methods (devices, equipment, staff, selected operational parameters, logistics, documentation of disturbances/incidents/failures, complaints, trouble spots, accessibility difficulties, etc.) and previous cleaning expenses (strategy and costs, etc.) in order to identify the economic … |
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Aug 28, 2019 "Planning is the conceptual anticipation of steps that seem necessary to achieve an objective. In the process, it is taken into consideration by which means the objective is to be achieved, how these means are to be applied and how the achieved results are to be controlled." [ [Wiki2001]] The achievement of the objective must not be taken for granted, because, to a large extent, the plan is always based on assumptions. It illustrates the complex interrelations … |
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Aug 28, 2019 Inspection plans are developed based on the "review and description of the drain and sewer system" that has been realised in step 1. Their purpose is to determine the on-site situation regarding the formation of deposits and the need for planned cleaning measures. Inspection plans combine statements with respect to the deposition behaviour from various operational processes, as for example in the course of manhole or shaft inspections (accessed by … |
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Aug 28, 2019 Following the acquisition of deposit data from the individual sections and manholes, the findings are classified and assessed. An example of a three-step model for the classification and assessment of data, which has been developed and applied in several research projects [ [Orth2008]] [ [Bosse2004]] [ [Freit2005]] is shown in Table 3‑4. Depending on both the size and structure of the drain and sewer system, other, more advanced assessment criteria, … |
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Aug 28, 2019 Based on the technical assessment and prioritisation of the deposit situation in the drain and sewer system and as part of the strategic cleaning plan, the resulting data is combined with the objectives mentioned in (Cleaning objectives and strategies). The final results show a prioritisation and area ranking (Image 3‑6). In addition to a technical assessment of the deposits, the results also include environment-related, operational, hydraulic, economic … |
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Aug 28, 2019 The cleaning measures are carried out based on operative cleaning planning in the form of operational or flushing plans. These plans include a priority ranking of the determined cleaning measures, specifying both the cleaning method of choice and associated cleaning devices and tools ( (Cleaning of drains and sewers)). Furthermore, the method-specific performance parameters are determined and specified considering the structural condition of the … |
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Aug 28, 2019 In step 3, the cleaning planning is implemented based on the developed operational and flushing plans. During cleaning, the collected waste is to be checked as regularly as possible. A higher proportion of mineral solids and broken pipe bits indicates serious damage, e.g. pipe fracture or collapse. In such situations, the cleaning procedures have to be stopped immediately and protective measures have to be taken. If required, a less destructive cleaning … |
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