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Enquiry into sewage pump station problems with specific focus on removing solidsTulleken, Joubert 03 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: There is a general lack of published research on sewage pump station problems and the removal
of solids in South African sanitary sewers. Research was undertaken to investigate the problems
at sewage pump stations by means of site visits, interviews, literature reviews and laboratory
experiments. An in-depth literature study is presented on sewage pump stations, pump station
problems and solids in sewers. The problems at sewage pump stations were categorised into
identifiable groups with possible generalised solutions. The site visits and literature review
indicated a specific lack of knowledge regarding screening baskets used to remove solids at
sewage pumping stations. This led to the experimental testing of a screening basket on full scale
in a controlled environment to develop an efficiency index for screening baskets. The efficiency
index was determined using fuzzy logic methodology with predetermined solids load, basket
height above the sump level and solids retention time. The fuzzy logic proved that the basket is
best operated halfway submerged, after one hour retention time and with degradable solids in the
system. The literature compiled and problems identified in this study were used as the backbone
for the development of a conceptual Decision Support Tool (DST) for sewage pump stations. The
DST is aimed at requiring limited inputs and providing maximum knowledge output and is
presented as a software tool in MS Excel format. The functionality was added by applying visual
basic applications in MS Excel user forms. The idea of developing a DST is to assist designers,
sewage service providers and operators with understanding the various components and for
problem identification pertaining to sewage pump stations in the future. The DST is relatively
self-explanatory with a user friendly visual interface that is easy to operate. This study sets the
scene for further research into efficiency indices pertaining to different components of sewage
pump stations and their application in comprehensive sewage pump decision support tools. / AFRIKAANSE OPSOMMING: Daar is 'n algemene gebrek aan gepubliseerde navorsing oor probleme met rioolpompstasies en
die verwydering van ongewenste voorwerpe in Suid-Afrikaanse sanitêre rioolsisteme. Navorsing
is gedoen om die probleme by rioolpompstasies te ondersoek deur middel van terreinbesoeke,
onderhoude, literatuurstudie en eksperimente in „n laboratorium. 'n Omvattende literatuurstudie is
op rioolpompstasies, probleme by pompstasies en ongewenste voorwerpe in rioolnetwerke
gedoen. Die probleme by rioolpompstasies is verdeel in identifiseerbare groepe met moontlike
oplossings. Die terreinbesoeke en literatuuroorsig het 'n spesifieke gebrek aan kennis met
betrekking tot skermmandjies, wat gebruik word om ongewenste voorwerpe by rioolpompstasies
te verwyder, aangedui. Dit het gelei tot die eksperimentele toetsing van 'n skermmandjie deur die
volskaalse opstelling in 'n beheerde omgewing om 'n doeltreffendheidsindeks vir skermmandjies
in die praktyk te ontwikkel. Die doeltreffendheidsindeks is bepaal deur gebruik te maak van
“fuzzy logic” metodologie met voorafbepaalde insette naamlik, die mandjie se hoogte bo die
watervlak, soort ongewenste voorwerpe en die tyd wat die voorwerpe aan water blootgestel is.
Die “fuzzy logic” bewys dat die mandjie die beste werking toon, halfpad onder die water, na „n
een uur van blootstelling aan water en met degradeerbare voorwerpe in die stelsel. Die literatuur
wat saamgestel is en probleme wat in hierdie studie geïdentifiseer is, is gebruik as die inhoud vir
die konseptuele “Decision Support Program” (DST) vir rioolpompstasies. Die DST het ten doel
om met beperkte insette die maksimum kennis te verskaf en word aangebied as 'n sagteware
instrument in MS Excel formaat. Die funksionaliteit is bygevoeg deur die toepassing van die
“visual basic applications” in MS Excel gebruikersvorms. Die doel van die ontwikkeling van 'n
DST is om ontwerpers, riooldiensverskaffers en operateurs te help om die verskillende funksies
en probleem-identifikasie met betrekking tot rioolpompstasies te begryp. Die DST is relatief
selfverduidelikend met 'n gebruikers vriendelike visuele koppelvlak wat maklik is om te bedryf.
Hierdie studie bied die basis vir verdere ondersoek na die doeltreffendheidsindekse met
betrekking tot die verskillende komponente van rioolpompstasies en die toepassing daarvan in
omvattende rioolpomp “DSTs”.
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